Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 1 of 90 PageID: 1
UNITED STATES DISTRICT COURT DISTRICT OF NEW JERSEY
AMPEREX TECHNOLOGY LIMITED, Civil Action No.______
Plaintiff, v. JURY TRIAL DEMANDED MAXELL, LTD. and MAXELL HOLDINGS, INC.,
Defendants.
COMPLAINT FOR DECLARATORY JUDGMENT
Plaintiff Amperex Technology Limited (“ATL”), for its complaint against Defendants
Maxell, Ltd. and Maxell Holdings, Inc. (collectively “Maxell”) alleges as follows:
NATURE OF ACTION
1. ATL brings this action seeking a declaratory judgment that the ATL lithium ion battery products including, without limitation ATL’s Cell Nos. 465867, 575577N, 785075 and “all
ATL products substantially similar in form, function, manufacture, or design” (“Accused ATL
Products”) do not infringe any of the following patents (collectively referred to as the “Maxell LIB
Patents”):
a. U.S. Patent No. 8,691,446 (“the ’446 Patent,” attached as Ex. 1),
b. U.S. Patent No. 9,350,019 (“the ’019 Patent,” attached as Ex. 2),
c. U.S. Patent No. 9,077,035 (“the ’035 Patent,” attached as Ex. 3), and
d. U.S. Patent No. 9,166,251 (“the ’251 Patent,” attached as Ex. 4).
2. ATL further seeks declaratory judgment that it has not infringed, induced others to
infringe, or contributed to the infringement by others under 35 U.S.C. § 271 (or any subsection
thereof) of the Maxell LIB Patents. Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 2 of 90 PageID: 2
3. ATL further seeks declaratory judgment that ATL’s customers have not infringed
and do not infringe under 35 U.S.C. § 271 (or any sub-section thereof) any claim of the Maxell
LIB Patents based on their purported making, sale, offer for sale, importation, and/or use of ATL’s products based on their purported making, using, importing, offering to sell, or selling products and/or services that include ATL’s products.
4. ATL also seeks to enjoin Defendants and their officers, employees, and agents from
(1) alleging that ATL or its customers infringe the Maxell LIB Patents; (2) taking any action to
suggest that ATL or its customers require a license from any of the Defendants for use of the
Maxell LIB Patents; or (3) pursuing infringement actions against ATL’s customers on the basis of those customers’ making, sale, offer for sale, importation, and/or use of ATL’s products, or on the basis of their making, using, importing, offering to sell, or selling products and/or services that include ATL’s products.
5. ATL seeks this necessary relief because Maxell, which has asserted that it has the right to license the Maxell LIB Patents, has threatened or implied litigation against ATL and its customers. Maxell has alleged that ATL’s customers infringe the Maxell LIB Patents by their use of the Accused ATL Products, and has demanded that ATL take a license to Maxell LIB Patents and pay an exorbitant, unreasonable, and unjustified royalty. Maxell has threatened litigation against ATL and has implied litigation against ATL’s customers if ATL does not pay for a license to the Maxell LIB Patents.
6. In making its infringement allegations against ATL and its customers, Maxell has referenced various components of the Accused ATL Products, ATL documentation, and alleged reverse engineering reports and thereby has established a substantial risk that Maxell will file a
lawsuit against ATL for infringement of the Maxell LIB Patents.
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7. In fact, on March 26, 2021, Maxell’s attorneys sent ATL a letter in which Maxell
threatened that if ATL does not “enter into a licensing agreement by Friday, April 9, 2021 , Maxell
will be left with no choice but to pursue litigation.”
8. Maxell’s allegations have cast inappropriate uncertainty over ATL and its lithium
ion battery products and have created a concrete and immediate justiciable controversy between
ATL and the Defendants.
9. Maxell’s allegations lack merit. ATL does not infringe any claim of the Maxell LIB
Patents. The Accused ATL Products do not infringe any claim of the Maxell LIB Patents. Nor do
ATL’s customers infringe any claim of the Maxell LIB Patents. Accordingly, ATL brings this case
to clear its name and that of its lithium ion products, and to protect its customers against meritless claims of infringement.
10. An actual and justiciable controversy therefore exists under 28 U.S.C. §§ 2201-
2202 between ATL and Maxell as to whether ATL is infringing or has infringed the Maxell LIB
Patents.
PARTIES
11. Plaintiff Amperex Technology Limited (“ATL”) is a Chinese corporation having a
principal place of business at 3503 Wharf Cable TV Tower, 9 Hoi Shing Road, Tsuen Wan N.T.,
Hong Kong.
12. Upon information and belief, Defendant Maxell, Ltd. is a Japanese corporation with
a registered place of business at 1 Koizumi, Oyamazaki, Oyamazaki-cho, Otokuni-gun, Kyoto,
Japan.
13. Upon information and belief, Defendant Maxell Holdings, Inc. is a Japanese corporation with a registered place of business at 1 Koizumi, Oyamazaki, Oyamazaki-cho,
Otokuni-gun, Kyoto, Japan.
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JURISDICTION AND VENUE
14. This action arises under the Declaratory Judgment Act, 28 U.S.C. §§ 2201 et seq., under the patent laws of the United States, 35 U.S.C. §§ 1 et seq. This Court has subject matter jurisdiction pursuant to 28 U.S.C. §§ 1331 and 1338(a).
15. Because this action presents an actual controversy with respect to the noninfringement of the Maxell LIB Patents, the Court may grant the declaratory relief sought pursuant to 28 U.S.C. §§ 2201 and 2202.
16. This Court has personal jurisdiction over Maxell by virtue of its sufficient minimum contacts with this forum based on business it conducts within the State of New Jersey, including in this judicial district.
17. Defendants are subject to this Court’s specific and general personal jurisdiction under due process and/or the New Jersey Long Arm Statute due at least to Defendants’ substantial business in this forum, including: (i) U.S. operations headquartered in this District; (ii) regularly doing or soliciting business, engaging in other persistent courses of conduct, and/or deriving substantial revenue from licensing its patents and from goods and services provided to individuals in New Jersey and in this District; and (iii) by virtue of its significant and active litigation it has initiated in the United States, including in this District. For example, Maxell has purposely availed itself of this Court by recently filing and continuing to litigate a patent infringement complaint in an unrelated case in this District. Thus, it would be reasonable and fair for this Court to exercise jurisdiction consistent with the principles underlying the U.S. Constitution, and would not offend traditional notions of fair play and substantial justice.
18. Upon further information and belief, Defendants have also established minimum contacts with this District and regularly transact and do business within this District, including advertising, promoting and selling products over the internet, through intermediaries,
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representatives and/or agents located within this District and litigating patent infringement actions
in this District.
19. Upon further information and belief, Defendants have purposefully directed
activities at citizens of this State and located within this District.
20. Venue in the District of New Jersey is proper pursuant to 28 U.S.C. § 1391(c)(3)
because Defendants are not residents in the United States and thus may be sued in any judicial district.
21. Venue in this district is also proper per 28 U.S.C. §§ 1391(b)(2) and 1400(b) because a substantial part of the events giving rise to the claims in this action occurred in this
District and Defendants’ agent resides or may be found in this District. Specifically, Maxell’s wholly-owned U.S. subsidiary, Maxell Corporation of America (“Maxell America”), is located at
3 Garret Mountain Plaza, Suite 300, Woodland Park, New Jersey, 07424-3352.
22. Upon information and belief, Maxell America functions as Maxell’s U.S.
operations, and Maxell has and continues to conduct substantial business with and through Maxell
America.
BACKGROUND
23. Founded in 1999, ATL is the world’s leading producer and innovator of lithium-
ion batteries. ATL is a global company known worldwide for its high-tech, high-volume prowess
in developing, producing and packaging high quality rechargeable lithium-ion battery cells and
packs.
24. ATL is now the world’s largest lithium ion battery manufacturer for smartphones
and one of the largest and most successful lithium ion battery manufacturer for all consumer
electronics. ATL’s market share continues to grow, and it has manufactured well over 1 billion
lithium ion batteries per year for the past three years. In contrast, upon information and belief,
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Maxell does not maintain a significant market share in the industry, and its production is a fraction
of ATL’s production.
25. In March 2020, Maxell contacted ATL and alleged that ATL’s products infringed
the Maxell LIB Patents, and demanded that ATL license the Maxell LIB Patents.
26. From May 2020 until February 2021, ATL and Maxell engaged in several rounds
of discussions regarding the Maxell LIB Patents.
27. On March 26, 2021, Maxell sent ATL correspondence that threatened it would
“pursue litigation” and “seek injunctive relief and recover monetary damages” over the Maxell
LIB Patents absence the entry of “a licensing agreement by Friday, April 9, 2021.”
28. Consequently, ATL has a reasonable apprehension, and there exists a substantial
risk, that Defendants will imminently file an action against ATL and allege that ATL infringes
directly and/or indirectly the Maxell LIB Patents. Maxell’s claims and allegations have cast
uncertainty over ATL and its products and have created a concrete and immediate justiciable
controversy between ATL and the Defendants. ATL thus brings this case to clear its name and that
of its lithium ion products, and to protect its customers against claims of infringement that lack
merit.
COUNT I - DECLARATORY JUDGMENT OF NONINFRINGEMENT OF U.S. PATENT NO. 8,691,446
29. ATL realleges and incorporates paragraphs 1 to 28 as if fully set forth herein.
30. Maxell Holdings Inc. is the owner of the ’446 Patent, entitled “Nonaqueous
secondary battery and method of using the same.” The ’446 Patent issued on April 8, 2014. A true and correct copy of the ’446 Patent is attached as Exhibit 1.
31. Maxell provided ATL with a claim chart purporting to demonstrate how each and every element of claim 1 of the ’446 Patent is met by ATL’s Accused Products and accusing ATL’s
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customers of infringement. By way of example, and without limitation, ATL products do not
infringe the ’446 Patent (under any sub-section of 35 U.S.C. § 271) because they do not meet the
(1) “wherein the positive electrode contains, as an active material, at least two lithium-containing
transition metal oxides having different average particle sizes, wherein said at least two lithium- containing transition metal oxides having different average particle sizes have different compositions of elements between them,” and (2) “said lithium-containing transition metal oxide having the smallest average particle size is a lithium-containing transition metal oxide represented by the formula (1): LixM1 yM2 zM3 vO2 (1) … x, y, z and v are numbers satisfying the equations respectively: 0.97 x<1.02, 0.8 y<1.02, 0.002 z 0.05, and 0 v 0.05” limitations, as required
by the claims of ≦the ’446 Patent.≦ The allegations≦ ≦ in this paragraph≦ ≦ are exemplary and do not
preclude ATL from contending that the claims are not infringed for additional reasons.
32. ATL has never had any intent to cause its customers or anyone else to infringe the
’446 Patent.
33. An actual and justiciable controversy therefore exists between ATL and Maxell
regarding whether any of the Accused ATL Products have infringed any of the asserted claims of
the ’446 Patent. A judicial declaration is necessary to determine the parties’ respective rights
regarding the ’446 Patent.
34. ATL seeks a judgment declaring that the Accused ATL Products do not directly or
indirectly infringe any asserted claims of the ’446 Patent, either literally or under the doctrine of
equivalents under 35 U.S.C. § 271 (or any sub-section thereof).
35. ATL further seeks and is entitled to a declaratory judgment that its customers do
not and have not infringed under 35 U.S.C. § 271 (or any sub-section thereof) any claim of the
’446 Patent by using the Accused ATL Products (or any other ATL Products).
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COUNT II - DECLARATORY JUDGMENT OF NONINFRINGEMENT OF U.S. PATENT NO. 9,350,019
36. ATL realleges and incorporates paragraphs 1 to 35 as if fully set forth herein.
37. Maxell Holdings Inc. is the owner of the ’019 Patent, entitled “Nonaqueous
secondary battery and method of using the same.” The ’019 Patent issued on May 24, 2016. A true
and correct copy of the ’019 Patent is attached as Exhibit 2.
38. Maxell provided ATL with a claim chart purporting to demonstrate how each and
every element of claim 1 of the ’019 Patent is met by the Accused ATL Products and accusing
ATL’s customers of infringement. By way of example, ATL products do not infringe the ’019
Patent (under any sub-section of 35 U.S.C. § 271) because they do not meet the (1) “wherein the
positive electrode contains, as an active material, at least two lithium-containing transition metal
oxides having different average particle sizes, wherein said at least two lithium-containing
transition metal oxides having different average particle sizes have different compositions of
elements between them,” and (2) “said lithium-containing transition metal oxide having the
smallest average particle size is a lithium-containing transition metal oxide represented by the
formula (1): LixM1 yM2 zM3 vO2 (1) … x, y, z and v are numbers satisfying the equations
respectively: 0.97 x<1.02, 0.8 y<1.02, 0.002 z 0.05, and 0 v 0.05” limitations, as required by the claims of ≦the ’019 Patent.≦ The allegations≦ ≦ in this paragraph≦ ≦ are exemplary and do not preclude ATL from contending that the claims are not infringed for additional reasons.
39. ATL has never had any intent to cause its customers or anyone else to infringe the
’019 Patent.
40. An actual and justiciable controversy therefore exists between ATL and Maxell regarding whether any of the Accused ATL Products have infringed any of the asserted claims of the ’019 Patent. A judicial declaration is necessary to determine the parties’ respective rights
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regarding the ’019 Patent.
41. ATL seeks a judgment declaring that the Accused ATL Products do not directly or
indirectly infringe any asserted claims of the ’019 Patent, either literally or under the doctrine of
equivalents under 35 U.S.C. § 271 (or any sub-section thereof).
42. ATL further seeks and is entitled to a declaratory judgment that its customers do
not and have not infringed under 35 U.S.C. § 271 (or any sub-section thereof) any claim of the
’019 Patent by using the Accused ATL Products (or any other ATL Products).
COUNT III - DECLARATORY JUDGMENT OF NONINFRINGEMENT OF U.S. PATENT NO. 9,077,035
43. ATL realleges and incorporates paragraphs 1 to 42 as if fully set forth herein.
44. Maxell Holdings Inc. is the owner of the ’035 Patent, entitled “Nonaqueous
secondary battery and method of using the same.” The ’035 Patent issued on July 7, 2015. A true
and correct copy of the ’035 Patent is attached as Exhibit 3.
45. Maxell provided ATL with a claim chart purporting to demonstrate how each and
every element of claim 1 of the ’035 Patent is met by the Accused ATL Products and accusing
ATL’s customers of infringement. By way of example, ATL products do not infringe the ’035
Patent (under any sub-section of 35 U.S.C. § 271) because they do not meet the (1) “a positive electrode having a positive electrode mixture layer, a negative electrode, and a nonaqueous electrolyte, wherein the positive electrode comprises, as active materials, at least two lithium- containing transition metal oxides having different average particle sizes” and (2) “the lithium- containing transition metal oxide having the smallest average particle size is a lithium-containing transition metal oxide represented by the formula (1): LixM1 yM2 zM3 vO2 (1)
… x, y, z and v are numbers satisfying the equations respectively: 0.97 x<1.02, 0.8 y<1.02,
0.002 z 0.05, and 0 v 0.05” limitations, as required by the claims of≦ the ’035 Patent.≦ The
≦ ≦ ≦ ≦
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allegations in this paragraph are exemplary and do not preclude ATL from contending that the
claims are not infringed for additional reasons.
46. ATL has never had any intent to cause its customers or anyone else to infringe the
’035 Patent.
47. An actual and justiciable controversy therefore exists between ATL and Maxell
regarding whether any of the Accused ATL Products have infringed any of the asserted claims of
the ’035 Patent. A judicial declaration is necessary to determine the parties’ respective rights
regarding the ’035 Patent.
48. ATL seeks a judgment declaring that the Accused ATL Products do not directly or
indirectly infringe any asserted claims of the ’035 Patent, either literally or under the doctrine of
equivalents under 35 U.S.C. § 271 (or any sub-section thereof).
49. ATL further seeks and is entitled to a declaratory judgment that its customers do
not and have not infringed under 35 U.S.C. § 271 (or any sub-section thereof) any claim of the
’035 Patent by using the Accused ATL Products (or any other ATL Products).
COUNT IV - DECLARATORY JUDGMENT OF NONINFRINGEMENT OF U.S. PATENT NO. 9,166,251
50. ATL realleges and incorporates paragraphs 1 to 49 as if fully set forth herein.
51. Maxell Holdings Inc. is the owner of the ’251 Patent, entitled “Battery separator and nonaqueous electrolyte battery.” The ’251 Patent issued on October 20, 2015. A true and correct copy of the ’251 Patent is attached as Exhibit 4.
52. Maxell provided ATL with a claim chart purporting to demonstrate how each and every element of claim 1 of the ’251 Patent is met by Accused ATL Products and accusing ATL’s customers of infringement. By way of example, ATL products do not infringe the ’251 Patent
(under any sub-section of 35 U.S.C. § 271) because they do not meet the limitation of “the
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thermoplastic resin constitutes a shutdown layer formed of a heat-shrinkable microporous film” as required by the claims of the ’251 Patent. The allegations in this paragraph are exemplary and do not preclude ATL from contending that the claims are not infringed for additional reasons.
53. ATL has never had any intent to cause its customers or anyone else to infringe the
’251 Patent.
54. An actual and justiciable controversy therefore exists between ATL and Maxell regarding whether any of the Accused ATL Products have infringed any of the asserted claims of
the ’251 Patent. A judicial declaration is necessary to determine the parties’ respective rights
regarding the ’251 Patent.
55. ATL seeks a judgment declaring that the Accused ATL Products do not directly or
indirectly infringe any asserted claims of the ’251 Patent, either literally or under the doctrine of
equivalents under 35 U.S.C. § 271 (or any sub-section thereof).
56. ATL further seeks and is entitled to a declaratory judgment that its customers do
not and have not infringed under 35 U.S.C. § 271 (or any sub-section thereof) any claim of the
’251 Patent by using the Accused ATL Products (or any other ATL Products).
DEMAND FOR JURY TRIAL
Plaintiff, under Rule 38 of the Federal Rules of Civil Procedure, requests a trial by jury of
any issues so triable by right.
REQUEST FOR RELIEF
WHEREFORE, ATL respectfully requests the Court to enter judgment in its favor and
against the Defendants as follows:
1. That neither ATL nor its products have infringed or do infringe under 35 U.S.C. §
271 (or any sub-section thereof) any claim of the Maxell LIB Patents;
2. That ATL’s customers’ products and/or services have not infringed and do not
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infringe under 35 U.S.C. § 271 (or any sub-section thereof) any claim of the Maxell LIB Patents
based on their purported use of ATL’s products;
3. Enjoining Defendants and their officers, employees or agents from (a) alleging that
ATL or its customers infringe the Maxell LIB Patents; (b) taking any action to suggest that ATL
or its customers require a license from Defendants for use of the Maxell LIB Patents; or (c) pursuing or continuing to pursue infringement actions against ATL’s customers on the basis of those customers’ use of ATL’s products;
4. Declaring this to be an exceptional case within the meaning of 35 U.S.C. § 285;
5. Awarding costs and reasonable attorneys’ fees incurred in connection with this action; and
6. For such other and further relief as the Court deems just and proper.
DATED: April 6, 2021 Respectfully submitted,
/s/ Becky L. Caruso Becky L. Caruso (local counsel) GREENBERG TRAURIG LLP 500 Campus Drive, Suite 400 Florham Park, NJ 07932 Tel: (973) 360-7900 [email protected]
GREENBERG TRAURIG LLP L. Howard Chen (to be admitted pro hac vice) Harold H. Davis (to be admitted pro hac vice) Yang Liu (to be admitted pro hac vice) Four Embarcadero Center, Suite 3000 San Francisco, CA 94111 (415) 655-1300 [email protected] [email protected] [email protected]
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Rose Cordero-Prey (to be admitted pro hac vice) MetLife Building 200 Park Avenue New York, NY 10166 (212) 801-9200 [email protected]
Vishesh Narayen (to be admitted pro hac vice) 101 East Kennedy Boulevard, Suite 1900 Tampa, FL 33602 (813) 318-5700 [email protected]
ATTORNEYS FOR PLAINTIFF AMPEREX TECHNOLOGY LIMITED
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Exhibit 1 Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 15 of 90 PageID: 15
USOO8691446B2
(12) United States Patent (10) Patent No.: US 8,691.446 B2 Sakata et al. (45) Date of Patent: Apr. 8, 2014
(54) NONAQUEOUS SECONDARY BATTERY AND (56) References Cited METHOD OF USING THE SAME U.S. PATENT DOCUMENTS (75) Inventors: Hideo Sakata, Ibaraki (JP); Fusaji Kita, 4,302,518 A 11/1981 Goodenough et al. Ibaraki (JP); Kumiko Ishizuka, Ibaraki 4,668,595 A 5, 1987 Yoshino et al. (JP) 5,147,738 A 9/1992 Toyoguchi et al. 2002fOO3745.6 A1 3/2002 Hosoya 2003/0068555 A1 4/2003 Naruoka ...... 429,2314 (73) Assignee: Hitachi Maxell, Ltd., Ibaraki-shi, Osaka 2004/001394.6 A1 1/2004 Abe et al. (JP) 2005, 0164082 A1* 7/2005 Kishi et al...... 429,188 2005/0266315 A1 12/2005 Sato et al. 2006/0024584 A1 2/2006 Kim et al...... 429,326 (*) Notice: Subject to any disclaimer, the term of this 2006.0035144 A1 2/2006 Shimizu et al. patent is extended or adjusted under 35 2006/01 15730 A1* 6/2006 Taniguchi et al...... 429,217 U.S.C. 154(b) by 765 days. 2006/0134521 A1* 6/2006 Shima ...... 429,231.1 2006, O1941 18 A1 8, 2006 Yew et al. (21) Appl. No.: 11/976,566 2006/0263690 A1* 11/2006 Suhara et al...... 429,231.3 FOREIGN PATENT DOCUMENTS (22) Filed: Oct. 25, 2007 CN 1776938 A 5, 2006 (65) Prior Publication Data (Continued) US 2008/O102369 A1 May 1, 2008 OTHER PUBLICATIONS Machine translation of JP 2001-176511, Honbo et al., Jun. 2001.* (30) Foreign Application Priority Data (Continued) Oct. 26, 2006 (JP) ...... 2006-290637 Primary Examiner — Kenneth Douyette (74) Attorney, Agent, or Firm — Birch, Stewart, Kolasch & (51) Int. Cl. Birch, LLP HOLM 4/50 (2010.01) HOLM 4/52 (2010.01) (57) ABSTRACT HOLM 4/525 (2010.01) A nonaqueous secondary battery having a positive electrode HOLM 6/16 (2006.01) having a positive electrode mixture layer, a negative elec (52) U.S. Cl. trode, and a nonaqueous electrolyte, in which the positive USPC ...... 429/231.95; 429/339; 429/231.3: electrode contains, as an active material, a lithium-containing 429/231.5; 429/223; 429/224 transition metal oxide containing a metal element selected (58) Field of Classification Search from the group consisting of Mg, Ti, Zr, Ge, Nb, Al and Sn, USPC ...... 429/188, 326,330, 331, 332, 200,339, the positive electrode mixture layer has a density of 3.5 g/cm 429/307, 245, 231, 231.5, 231.95, 223, 224, or larger, and the nonaqueous electrolyte contains a com 429/231.3 pound having two or more nitrile groups in the molecule. See application file for complete search history. 5 Claims, 2 Drawing Sheets
: s
NN N assassistiaaser Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 16 of 90 PageID: 16
US 8,691.446 B2 Page 2
(56) References Cited JP 2006-245001 A 9, 2006 WO WO 2005/069423 A1 7/2005 WO WO 2005,117198 A1 12/2005 FOREIGN PATENT DOCUMENTS WO WO 2006/091019 A1 8, 2006 WO 2007-042302 A 2, 2007 JP 55-136131 A 10, 1980 WO WO-2004/03.0125 A1 * 4, 2008 ...... HO1 M 4/58 JP 3-201368 A 9, 1991 JP 4-171659 A 6, 1992 OTHER PUBLICATIONS JP T-1763O2 A 7, 1995 JP T-176322 A 7, 1995 JP 2001-167763. A 6, 2001 Mohine Translation of JP 2005/050582 A, Kikuchi, Kazuhiro, Feb. JP 2001-176511 A 6, 2001 - JP 2001 176511 A * 6, 2001 ...... HO1 M 4/58 Chinese Office Action for Application No. 200710180385.4, dated JP 2001-319652. A 11, 2001 Feb. 10, 2011. JP 2002-216745. A 8, 2002 Submission of Publications for Application No. 2006-290637, dated JP 2002-270238 A 9, 2002 Mar. 14, 2011. JP 2003-217582 A T 2003 A Japanese Office Action, dated Oct. 11, 2011, for Japanese Appli E 58:53:5. A 1858: cation No. 2006-290637. JP 2005050582. A * 2/2005 ...... HO1 M 4/O2 Japanese Office Action, dated May 17, 2013, for Japanese Patent JP 2005-339.970. A 12/2005 Application No. 2011-261150. JP 2006-73513. A 3, 2006 JP 2006-164742 A 6, 2006 * cited by examiner Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 17 of 90 PageID: 17
U.S. Patent Apr. 8, 2014 Sheet 1 of 2 US 8,691.446 B2
Fig. A
Fig. 1B Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 18 of 90 PageID: 18
U.S. Patent Apr. 8, 2014 Sheet 2 of 2 US 8,691.446 B2
Fig. 2
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US 8,691.446 B2 1. 2 NONAQUEOUS SECONDARY BATTERY AND To solve such a problem, many attempts have been made to METHOD OF USING THE SAME add a different metal element to LiCoO, (cf.JP-A-4-171659, JP-A-3-201368, JP-A-7-176302 and JP-A-2001-167763). FILED OF THE INVENTION In addition, attempts have been made to use a battery in a high-voltage range of 4.2V or higher (cf.JP-A-2004-29.6098, The present invention relates to a nonaqueous secondary JP-A-2001-176511 and JP-A-2002-270238). battery having a high capacity, good charge-discharge cycle In years to come, a secondary battery will be required to characteristics and high reliability Such as safety. have a higher capacity and also better reliability than the conventional batteries. In general, the battery capacity can be RELATED ART 10 greatly improved by raising the content of an active material in electrodes or by increasing an electrode density, in particu In recent years, the secondary battery is an indispensable, lar, the density of a positive electrode mixture layer. However, important device as a power source of a personal computer or according to such capacity-increasing measures, the reliabil ity of the battery including storage characteristics gradually a cellular phone, or a power Source for an electric Vehicle oran 15 decreases. electric power storage. Accordingly, in order to meet requirements for the increase In particular, in applications for a mobile communication of the electric capacity, it is highly desired to provide a battery device Such as a portable computer and a personal digital which uses a material that generates a higher electromotive assistant, the battery is required to be made Smaller and to force (voltage range) than LiCoO and has a stable crystalline trim-weight. Under the current circumstances, however, the structure capable of being stably and reversibly charged and system of the battery is not easily made compact or light discharged, and which further satisfies reliability such that the weight, since an electric power consumed by a back light of a safety of the conventional batteries can be maintained and the liquid crystal display panel or consumed to control the draw battery does not expand during storage when the density of ing of graphics is large, or the capacity of a secondary battery the positive electrode mixture layer is increased. is not sufficiently large. In particular, a personal computer is 25 When the discharge final voltage of a conventional battery progressively multi-functionalized by mounting a digital ver comprising LiCoO as a positive electrode active material is satile disc (DVD) drive and so on. Thus, the power consump made higher than 3.2 V, the battery cannot be completely tion thereof tends to increase. For this reason, it is highly discharged since the Voltage in the final stage of the discharge required to increase the electric capacity of a secondary bat significantly falls. Thus, an electric quantity efficiency of tery, in particular, the discharge capacity, when the Voltage of 30 discharge relative to charging remarkably decreases. Since a single battery is 3.3 V or higher. the complete discharge cannot be attained, the crystalline Attention is paid to electric vehicles, which discharge no structure of LiCoO easily decays, and thus the charge-dis exhaust gas and make less noise in association with the charge cycle life is shortened. This phenomenon remarkably increase of global environmental problems. Recently, parallel appears in the above-mentioned high Voltage range. hybrid electric vehicles (HEV), which adopt a system of 35 Under a charging condition that the final Voltage at full storing regenerative energy generated at the time of braking in charging is set to 4.2V or higher in the conventional battery, a battery and making effective use of the energy, or using an apart from shortening of the charge-discharge cycle life or the electric energy stored in a battery at the time of engine starting decrease of the thermal stability caused by the decay of the to increase the efficiency of the engine system, have gained crystalline structure of the positive electrode active material, popularity. However, since the electric capacity of the cur 40 the electrolytic solution (a solvent) is oxidatively decom rently used battery is small, a plurality of batteries should be posed due to the increase of the active sites in the positive used to generate a Sufficient Voltage. For this reason, prob electrode active material, whereby a passivation film is lems such that a space in the vehicle should be made smaller formed on the surface of the positive electrode and thus the and that the stability of the vehicle body deteriorates arise. internal resistance of the battery increases so that the load Among secondary batteries, a lithium secondary battery 45 characteristic may deteriorate. using a nonaqueous electrolyte attracts attention, since it gen erates a high Voltage, has a lightweight and is expected to SUMMARY OF THE INVENTION achieve a high energy density. In particular, a lithium second ary battery disclosed in JP-A-55-136131, in which a lithium An object of the present invention is to provide a nonaque containing transition metal oxide, for example, LiCoO, is 50 ous secondary battery having a high capacity, good charge used as a positive electrode active material, and metal lithium discharge cycle characteristics and high storage characteris is used as a negative electrode active material, is expected to tics. attain a high energy density, since it has an electromotive Accordingly, the present invention provides a nonaqueous force of 4V or higher. secondary battery comprising: a positive electrode having a However, at present, in the case of a LiCoO based second 55 positive electrode mixture layer, a negative electrode, and a ary battery which uses LiCoO, as a positive electrode active nonaqueous electrolyte, wherein the positive electrode con material and a carbonaceous material Such as graphite as a tains, as an active material, at least one lithium-containing negative electrode active material, a charge final Voltage transition metal oxide comprising at least one metal element thereof is usually 4.2 V or less. According to this charging selected from the group consisting of Mg, Ti, Zr, Ge, Nb, Al condition, the charge capacity is only about 60% of the theo 60 and Sn, the positive electrode mixture layer has a density of at retical capacity of LiCoO. The electric capacity may be least 3.5 g/cm, and the nonaqueous electrolyte contains a increased by increasing the charge final Voltage to higher than compound having at least two nitrile groups in the molecule. 4.2V. However, with the increase of the charge capacity, the The nonaqueous secondary battery of the present invention crystalline structure of LiCoO decays so that the charge can be charged at a high Voltage and thus has a large capacity, discharge cycle life may be shortened, or the crystalline struc 65 since the positive electrode mixture layer has a density of a ture of LiCoO may be destabilized. Accordingly, the thermal specific value or larger So as to increase the filled amount of stability of the battery deteriorates. the positive electrode active material in the positive electrode Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 20 of 90 PageID: 20
US 8,691.446 B2 3 4 mixture layer, and a lithium-containing transition metal oxide cyclic ester. Mixed solvents each comprising an acyclic ester comprising a specific metal element, which is highly stable in as a main solvent and a cyclic ester are particularly Suitable. a charged state at a high Voltage, is used as a positive electrode Apart form the esters exemplified above, the following active material. Solvents may also be used: acyclic phosphoric acid triesters Furthermore, since the positive electrode active material Such as trimethyl phosphate; ethers such as 1,2-dimethoxy used in the nonaqueous secondary battery of the present ethane, 1,3-dioxolane, tetrahydrofuran, 2-methyl-tetrahydro invention has good stability, the decay of the active material is furan and diethyl ether, nitriles and dinitriles; isocyanates; Suppressed when the charging and discharging of the battery and halogen-containing solvents. Furthermore, amine or are repeated. Thereby, the nonaqueous secondary battery has imide organic solvents may be used. 10 Examples of the electrolyte salt to be dissolved in the good charge-discharge cycle characteristics. Solvent during the preparation of the nonaqueous electrolytic In addition, the nonaqueous electrolyte used in the non solution include LiClO, LiPF LiBF LiAsF, LiSbF. aqueous secondary battery of the present invention contains a LiCFSO, LiCFSO, LiCFCO, LiCF (SO), LiN compound having at least two nitrile groups in the molecule. (RfSO) (Rf'SO), LiC(RfSO), LiCFSO, wherein Such a nitrile compound acts on the surface of the positive 15 n>2, and LiN(RfCSO), wherein Rf and Rf each represent a electrode and functions to prevent the direct contact of the fluoroalkyl group. They may be used alone or in combination positive electrode and the nonaqueous electrolyte. Thus, the of two or more thereof. Among these electrolyte salts, par reaction of the positive electrode and the nonaqueous elec ticularly preferred are fluorine-containing organic lithium trolyte is suppressed, whereby the generation of a gas in the salts having 2 or more carbon atoms, since Such lithium salts battery by Such a reaction is prevented. Accordingly, the have a large anionic property and further ion separation easily suppression of the reaction of the positive electrode and the occurs so that the salts are easily dissolved in the above nonaqueous electrolyte and the use of the positive electrode mentioned solvents. The concentration of the electrolyte salt active material having high stability Synergistically function in the nonaqueous electrolytic solution is not particularly to prevent the expansion of the battery during the storage of limited, and it is preferably 0.3 mol/L or more, more prefer the charged battery at a high temperature and thus to improve 25 ably 0.4 mol/L or more, while it is preferably 1.7 mol/L or the storage characteristics of the battery. less, more preferably 1.5 mol/L or less. Consequently, the nonaqueous secondary battery of the According to the present invention, the nonaqueous elec present invention has good charge-discharge cycle character trolyte should contain a compound having at least two nitrile istics and good storage characteristics. The nonaqueous sec groups in the molecule. ondary battery of the present invention can be charged at a 30 The nitrile compound used according to the present inven high positive electrode Voltage in a range of 4.35 to 4.6V with tion can form a protective film on the surface of the positive reference to the potential of lithium, and thus it can be used in electrode active material during charging, in particular, initial applications which require a high output. charging, of the battery, and the protective film Suppresses the direct contact of the positive electrode and the nonaqueous BRIEF DESCRIPTION OF THE DRAWINGS 35 electrolyte. Therefore, the battery of the present invention comprising the nonaqueous electrolyte containing the com FIGS. 1A and 1B schematically show one example of the pound having at least two nitrile groups in the molecule can nonaqueous secondary battery of the present invention. FIG. prevent the generation of a gas in the battery due to the 1A is a plan view thereof and FIG. 1B is a partial vertical reaction of the positive electrode and the nonaqueous elec section thereof. 40 trolyte, when it is stored at a high temperature of, for example, FIG. 2 shows a perspective view of the nonaqueous sec about 85°C., in a charged state, since the protective film ondary battery illustrated in FIGS. 1A and 1B. formed of the nitrile compound prevents the positive elec trode and the nonaqueous electrolyte from direct contact and DETAILED DESCRIPTION OF THE INVENTION in turn prevents the reaction therebetween. The gas generated 45 by the reaction of the positive electrode and the nonaqueous The nonaqueous secondary battery of the present invention electrolyte in the battery causes the expansion of the battery may have Such a configuration that a laminate electrode body resulting in the decrease of the battery characteristics due to having a positive electrode with a positive electrode mixture the increase of the distance between the positive and negative layer and a negative electrode which are laminated each other electrodes. However, the battery of the present invention can withinserting a separator between them, or a wound electrode 50 Suppress the expansion of the battery caused by the gas during body in which the laminate electrode body is wound is storage and thus has good storage characteristics. enclosed within a housing together with a nonaqueous elec The compound having at least two nitrile groups in the trolyte. molecule may be one having two nitrile groups in the mol In the nonaqueous secondary battery of the present inven ecule, one having three nitrile groups in the molecule, etc. tion, the nonaqueous electrolyte is preferably a nonaqueous 55 Among them, a dinitrile compound, that is, a compound Solvent-base electrolytic solution comprising an electrolyte having two nitrile groups in the molecule is preferable since it salt Such as a lithium salt dissolved in a nonaqueous solvent has a better property to form the protective film and thus to Such as an organic solvent, from the viewpoint of electric prevent the reaction of the positive electrode and the nonaque characteristics or handling easiness. A polymer electrolyte or ous electrolyte. The dinitrile compound is preferably a com a gel electrolyte may be used without any problem. 60 pound of the formula: NC R—CN wherein R is a linear or The solvent in the nonaqueous electrolytic solution is not branched hydrocarbon group having 1 to 10 carbon atoms, particularly limited, and examples thereof include acyclic preferably a linear or branched alkylene group having 1 to 10 esters such as dimethyl carbonate, diethyl carbonate, ethyl carbon atoms. methyl carbonate, and methyl propyl carbonate; cyclic esters Specific examples of the dinitrile compound include mal having a high dielectric constant, such as ethylene carbonate, 65 ononitrile, Succinonitrile, glutaronitrile, adiponitrile, 1,4-di propylene carbonate, butylene carbonate, and vinylene car cyanoheptane, 1,5-dicyanopentane, 1,6-dicyanohexane, 1.7- bonate; and mixed solvents comprising an acyclic ester and a dicyanoheptane, 2,6-dicyanoheptane, 1,8-dicyanooctane, Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 21 of 90 PageID: 21
US 8,691.446 B2 5 6 2,7-dicyanooctane, 1,9-dicyanononane, 2,8-dicyanononane, compound that can be oxidized at a lower Voltage than the 1,10-dicyanodecane, 1,6-dicyanodecane, 2,4-dimethylglu alkaryl compound in the nonaqueous electrolytic Solution is taronitrile, etc. preferably 0.1% by weight or more, more preferably 0.2% by The nonaqueous electrolyte containing the nitrile com weight or more, while it is preferably 1% by weight or less, pound may be prepared by any method. For example, the more preferably 0.5% by weight or less. nitrile compound and the electrolyte salt are dissolved in the Furthermore, a Surface protecting coating can beformed on solvent described above by a conventional method. the surface of the positive electrodeactive material in the step The amount of the nitrile compound is preferably at least of initial charging of the battery, when the nonaqueous elec 0.005% by weight, more preferably at least 0.01% by weight, trolytic Solution contains at least one compound selected still more preferably at least 0.05% by weight, based on the 10 from the group consisting of halogen-containing organic Sol whole weight of the nonaqueous electrolyte, from the view vents (e.g., halogen-containing carbonates), organic Sulfur point of effectively utilizing the effects of the addition of the compounds, fluorine-containing organic lithium salts, phos nitrile compound. However, when the amount of the nitrile phorus-containing organic solvents, silicon-containing compound in the electrolyte is too large, the charge-discharge organic solvents, nitrogen-containing organic solvents other cycle characteristics of the battery tends to decrease although 15 than the compounds having at least two nitrile groups in the the storage characteristics of the battery is improve. Thus, the molecule, etc. In particular, the fluorine-containing organic amount of the nitrile compound is preferably 1% or less, more compounds such as fluorine-containing carbonate esters, the preferably 0.75% by weight or less, still more preferably organic Sulfur compounds and the fluorine-containing 0.5% by weight or less, based on the whole weight of the organic lithium salts are preferred. Specific examples thereof nonaqueous electrolyte. include F-DPC CFCHO(C=O)CCHCF), F-DEC Besides the nitrile compound, the nonaqueous electrolytic ICF.CHO(C–O)OCHCF, HFE7100 (CFOCH), butyl solution may contain other additive or additives. A preferred sulfate (CHOSOOCH), methylethylene sulfate example of the additive is a nonionic aromatic compound. ( OCH(CH)CHO )SO), butyl sulfate Specific examples thereof include aromatic compounds hav (CHSOCH), a polymer imide salt (I N(Li)SOOCH ing an alkyl group bonded to an aromatic ring (e.g., cyclo 25 (CF)..CHOSO I, wherein n is from 2 to 100), hexylbenzene, isopropylbenzene, tert-butylbenzene, tert (CFSO)NLi, and (CF)2CHOSO-NLi. amylbenzene, octylbenzene, toluene and Xylene); aromatic Such additives may be used alone. It is particularly prefer compounds having a halogen group bonded to an aromatic able to use a fluorine-containing organic solvent together with ring (e.g., fluorobenzene, difluorobenzene, trifluorobenzene a fluorine-containing organic lithium salt. The amount of and chlorobenzene); aromatic compounds having an alkoxy 30 such an additive added is preferably 0.1% by weight or more, group bonded to an aromatic ring (e.g., anisole, fluoroanisole, more preferably 2% by weight or more, particularly prefer dimethoxybenzene and diethoxybenzene); aromatic car ably 5% by weight or more, while it is preferably 30% by boxylic acid esters such as phthalic acid esters (e.g., dibutyl weight or less, more preferably 10% by weight or less, each phthalate and di-2-ethylhexyl phthalate) and benzoic acid based on the whole weight of the nonaqueous electrolytic esters; carbonic acid esters having a phenyl group (e.g., meth 35 solution. When the amount of the additive is too large, the ylphenyl carbonate, butylphenyl carbonate and diphenyl car electric characteristics of the battery may deteriorate. When bonate); phenyl propionate; and biphenyl. Among them, the the amount is too small, a good coating may hardly beformed. compounds having an alkyl group bonded to an aromatic ring When the battery comprising the nonaqueous electrolytic (alkaryl compounds) are preferred, and cyclohexylbenzene is Solution containing the above-mentioned additive(s) is particularly preferred. 40 charged, particularly at a high Voltage, a Surface protecting The aromatic compounds exemplified above can also form coating that contains fluorine or Sulfur atoms is formed on the a film on the surface of the active material in the positive positive electrode active material surface. This surface pro electrode or the negative electrode in the battery. These aro tecting coating may contain either fluorine atoms or Sulfur matic compounds may be used alone, while more advanta atoms. Preferably, the coating contains both of fluorine atoms geous effects can be attained by the use of two or more of the 45 and Sulfur atoms. aromatic compounds together. Particularly advantageous The amount of the Sulfur atoms in the Surface protecting effects can be attained on the improvement of the safety of the coating formed on the positive electrode active material Sur battery by the use of the alkaryl compound together with an face is preferably 0.5 atomic '% or more, more preferably 1 aromatic compound, which can be oxidized at a lower Voltage atomic '% or more, particularly preferably 3 atomic '% or than the alkaryl compound, Such as biphenyl. 50 more. However, when the amount of the sulfur atoms in the The method for adding the aromatic compound in the non positive electrode active material Surface is too large, the aqueous electrolytic Solution is not particularly limited. In discharge characteristic of the battery tends to decrease. Thus, general, the aromatic compound is added to the nonaqueous the amount is preferably 20 atomic 96 or less, more preferably electrolytic solution prior to the fabrication of the battery. 10 atomic '% or less, particularly preferably 6 atomic 96 or The content of the aromatic compound in the nonaqueous 55 less. electrolytic solution is preferably 4% by weight or more from The amount of the fluorine atoms in the Surface protecting the viewpoint of the safety, and it is preferably 10% by weight coating formed on the positive electrode active material Sur or less from the viewpoint of the load characteristic. When face is preferably 15 atomic 96 or more, more preferably 20 two or more aromatic compounds are used together, the total atomic '% or more, particularly preferably 25 atomic '% or amount thereof is within the above-mentioned range. When 60 more. However, when the amount of the fluorine atoms in the the alkaryl (alkylaryl) compound and the aromatic compound positive electrode active material Surface is too large, the which can be oxidized at a lower voltage that the alkaryl discharge characteristic of the battery tends to fall. Thus, the compound are used in combination, the content of the alkaryl amount of the fluorine atoms is preferably 50 atomic '% or compound in the nonaqueous electrolytic solution is prefer less, more preferably 40 atomic '% or less, particularly pref ably 0.5% by weight or more, more preferably 2% by weight 65 erably 30 atomic 96 or less. or more, while it is preferably 8% by weight or less, more In order to improve the charge-discharge cycle character preferably 5% by weight or less. The content of the aromatic istic of the battery, preferably, the nonaqueous electrolytic Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 22 of 90 PageID: 22
US 8,691.446 B2 7 8 Solution contains at least one carbonate compound selected Herein, the density of the positive electrode mixture layer from the group consisting of vinylene carbonates, such as may be obtained by the following measuring method: The ( OCH=CHO )C=O, ( OCH=C(CH)O ) C=O positive electrode is cut to form a sample piece having a and (—OC(CH)—C(CH)O )C—O, and derivatives predetermined area, the sample piece is weighed with an thereof cyclic carbonate esters having a vinyl group Such as electronic balance having a minimum scale of 1 mg, and then vinylethylene carbonate (—OCH CH(—CH=CH)O—) the weight of the current collector is subtracted from the C=O); and fluorine-substituted ethylene carbonates, such as weight of the sample piece to calculate the weight of the ( OCH CHFO )C=O and ( OCHF CHFO-) positive electrode mixture layer. The total thickness of the C—O. The addition amount thereof is preferably 0.1% by positive electrode is measured atten points with a micrometer 10 having a minimum scale of 1 Lum. Then, the thickness of the weight or more, more preferably 0.5% by weight or more, current collector is subtracted from the resultant individual particularly preferably 2% by weight or more based on the thicknesses, and the thicknesses of the positive electrode whole weight of the nonaqueous electrolytic solution. When mixture layer measured at ten points are averaged. From the the addition amount thereof is too large, the load character averaged thicknesses of the positive electrode mixture layer istic of the battery tends to decrease. Thus, the addition 15 and the surface area, the volume of the positive electrode amount is preferably 10% by weight or less, more preferably mixture layer is calculated. Finally, the weight of the positive 5% by weight or less, particularly preferably 3% by weight or electrode mixture layer is divided by the volume thereof to less based on the whole weight of the nonaqueous electrolytic obtain the density of the positive electrode mixture layer. Solution. The positive electrode active material contained in the In the present invention, the nonaqueous electrolyte may be positive electrode mixture layer comprises a lithium-contain a gel-form polymer electrolyte besides the nonaqueous elec ing transition metal oxide comprising at least one metal ele trolytic solution described above. The gel-form polymer elec ment selected from the group consisting of Mg, Ti, Zr, Ge. trolyte corresponds to a product obtained by the gelation of Nb, Al and Sn. The use of the lithium-containing transition the nonaqueous electrolytic Solution with a gelling agent. For metal oxide can improve the charge-discharge cycle charac the gelation of the nonaqueous electrolytic solution, the fol 25 teristics of the battery, since it has good stability, in particular, lowing gelling agents may be used: a linear polymer Such as in the charged State at a high Voltage, so that the decay of the polyvinylidene fluoride, polyethylene oxide or polyacryloni compound is prevented when the charge-discharge cycle is trile, or a copolymer thereof, or a polyfunctional monomer repeated. Since the lithium-containing transition metal oxide which can be polymerized by irradiation with actinic rays has good stability, it can improve the storage characteristics Such as ultraviolet rays or electron beams (e.g., an acrylate 30 and the reliability such as safety of the battery. having 4 or more functionalities such as pentaerythritol tet The positive electrode active material preferably has a par raacrylate, ditrimethylolpropane tetraacrylate, ethoxylated ticle size frequency peak in a particle size range larger than a pentaerythritol tetraacrylate, dipentaerythritol hydroxypen midpoint d between do and do inaparticle size distribution taacrylate, or dipentaerythritol hexaacrylate; or a methacry curve, which obtained by a method for measuring an average late having 4 or more functionalities, which are analogous to 35 particle size described below. To obtain a positive electrode the above acrylates. In the case of the monomer, the monomer active material having Such a particle size distribution, pref itself does not cause the gelling of the electrolytic solution, erably, at least two lithium-containing transition metal oxides but the polymer formed from the monomer acts as a gelling having different average particle sizes are used. When a agent. lithium-containing transition metal oxide having a larger When a polyfunctional monomer is used to gel the electro 40 average particle size and one having a smaller average par lytic Solution as described above, a polymerization initiator ticle size are used in combination, the particles of the latter may optionally be used. Examples of the polymerization infill the gaps among the particles of the former. Thus, the initiator include benzoyls, benzoin alkyl ethers, benzophe positive electrode mixture layer having a large density as nones, benzoylphenylphosphine oxides, acetophenones, described above can be easily formed. thioxanthones and anthraquinones. As a sensitizer for the 45 The “average particle size of the lithium-containing tran polymerization initiator, an alkylamine oran aminoester may sition metal oxide(s) used herein means a 50% diameter value be used. (ds), that is, an median diameter, read from an integral frac In the present invention, the nonaqueous electrolyte may be tion curve based on Volumes, which is obtained by integrating a solid electrolyte besides the nonaqueous electrolytic solu the Volumes of the particles from a smaller particle size mea tion or the gel-form polymer electrolyte. The solid electrolyte 50 sured by a MICROTRAC particle size analyzer (HRA9320 may be an inorganic Solid electrolyte or an organic Solid available from NIKKISO Co., Ltd.). Analogously, do and do electrolyte. means a 10% diameter value and a 90% diameter value, The positive electrode according to the present invention respectively. may have a structure Such that the positive electrode mixture The mixture of “at least two lithium-containing transition layer containing the positive electrode active material is 55 metal oxides having different average particle sizes' prefer formed on one or both of the surfaces of an electrode collec ably has a particle size frequency peak in a particle size range tOr. larger than a midpoint d between do and doo in a particle The positive electrode mixture layer according to the size distribution curve, as described above. Hereinafter, a present invention may have a density of 3.5 g/cm or more, particle size corresponding to the particle size frequency peak more preferably 3.6 g/cm or more, particularly preferably 60 is expressed by “d”. In a preferred embodiment, the ratio of 3.8 g/cm or more. With such a density, the capacity of the d, to d. (d/d) is at least 1.05, more preferably at least 1.2, battery can be increased. However, when the density of the most preferably at least 1.3. Furthermore, the ratio of d to d, positive electrode mixture layer is too high, the wettability is preferably 1.6 or less, more preferably 1.5 or less, most with the nonaqueous electrolyte, which will be explained preferably 1.45 or less. In a more preferred embodiment, the later, decreases. Thus, the density is preferably 4.6 g/cm or 65 lithium-containing transition metal oxide mixture has at least less, more preferably 4.4 g/cm or less, particularly prefer two peaks in the particle size distribution curve. When the ably 4.2 g/cm or less. lithium-containing transition metal oxides have the same Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 23 of 90 PageID: 23
US 8,691.446 B2 10 d/d of 1.3, the lithium-containing transition metal oxide weight or more. When the positive electrode active material mixture having at least two peaks in the particle size distri (B) is contained in an amount of the above-mentioned range, bution curve can increase the density of the positive electrode the gaps between the particles of the lithium-containing tran mixture layer by 0.1 g/cm or more. When the particle size sition metal oxide having a relatively large particle size are distribution curve has two or more peaks, it can be divided easily filled therewith so that the density of the positive elec into a distribution curve corresponding to particles having a trode mixture layer is increased. When the content of the larger particle size and a distribution curve corresponding positive electrode active material (B) is too large, the density particles having a smaller particle size by a common peak of the positive electrode mixture layer is hardly be increased. separation method and then an average particle size (ds) of Thus, the content of the positive electrode active material (B) the respective lithium-containing transition metal oxide and a 10 is preferably 60% by weight or less, more preferably 50% by mixing ratio of the lithium-containing transition metal oxides weight or less, particularly preferably 40% by weight or less. having the different average particle sizes can be calculated Accordingly, when the lithium-containing transition metal from the particle sizes and the cumulative volumes of the oxides contained in the positive electrode are only the positive particles. electrode active materials (A) and (B), the content of the When the average particle size of the lithium-containing 15 positive electrode active material (A) is preferably 40% by transition metal oxide having the largest average particle size weight or more, more preferably 50% by weight or more, (hereinafter referred to as “positive electrode active material particularly preferably 60% by weight or more of the oxides, (A)) is represented by A, and that of the lithium-containing while it is preferably 95% by weight or less, more preferably transition metal oxide having the Smallest average particle 90% by weight or less, particularly preferably 80% by weight size (hereinafter referred to as “positive electrode active or less. material (B)) is expressed by B, the ratio of B to A (i.e., B/A) Among the lithium-containing transition metal oxides con is preferably from 0.15 to 0.6. When the average particle sizes tained in the positive electrode, the positive electrode active of the two positive electrode active materials (A) and (B) have material (B) having the Smallest average particle size has the such a ratio B/A, the density of the positive electrode mixture above-mentioned average particle size. Such a lithium-con layer can be easily increased. 25 taining transition metal oxide having a relatively small par The positive electrode active material (A) preferably has an ticle size has low stability, for example, in a state that the average particle size of 5um or more, more preferably 8 um battery is charged at a high Voltage, so that the oxide may or more, particularly preferably 11 Lum or more. When the damage the reliability including the safety of the battery. average particle size of the positive electrode active material When two or more lithium-containing transition metal (A) is too small, the density of the positive electrode mixture 30 oxides having the different average particle sizes are used, a layer may hardly be increased. When the average particle size lithium-containing transition metal oxide comprising at least is too large, the battery characteristic tends to decrease. Thus, one metal element M selected from the group consisting of the average particle size is preferably 25 um or less, more Mg, Ti, Zr, Ge, Nb, Al and Sn is preferably used at least as the preferably 20 um or less, particularly preferably 18 um or positive electrode active material (B) which is the lithium less. 35 containing transition metal oxide having the Smallest average The positive electrode active material (B) preferably has an particle size, since the lithium-containing transition metal average particle size of 10 Lim or less, more preferably 7 um oxide comprising the metal element M has the improved or less, particularly preferably 5um or less. When the average stability and thus Surely increases the charge-discharge cycle particle size of the positive electrode active material (B) is too characteristics of the battery and also improves the storage large, the positive electrode active material (B) does not easily 40 characteristics and the reliability including the safety of the fill the gaps between the particles of the lithium-containing battery. transition metal oxide having a relatively large particle size in When two or more lithium-containing transition metal the positive electrode mixture layer, so that the density of this oxides having the different average particle sizes are used, the layer may hardly be increased. When the average particle size positive electrode active material (B) having the smallest is too small, the Volume of Voids among the Small particles 45 average particle size preferably comprises the metal element increases so that the density of the positive electrode mixture M. More preferably, the lithium-containing transition metal layer may not be increased. Thus, the average particle size of oxide other than the positive electrode active material (B), for the positive electrode active material (B) is preferably 2 um or example, the positive electrode active material (A) having the more, more preferably 3 um or more, particularly preferably largest average particle size or the lithium-containing transi 4 um or more. 50 tion metal oxide having the average particle size between The positive electrode active materials according to the those of the positive electrode active materials (A) and (B), present invention may contain only two lithium-containing comprises the metal element M. When the lithium-contain transition metal oxides having different average particle ing transition metal oxide other than the positive electrode sizes, for example, the positive electrode active materials (A) active material (B) comprises the metal element M, the reli and (B) as descried above, while the positive electrode active 55 ability including the safety of the battery can be further materials may contain three or more, for example, three, four improved, since Such a lithium-containing transition metal or five lithium-containing transition metal oxides having dif oxide has the improved stability, in particular, the stability in ferent average particle sizes, for example, the positive elec a state that the battery is charged at a high Voltage as described trode active materials (A) and (B) and one or more lithium above. containing transition metal oxides having an average particle 60 The positive electrode active material (B) is preferably a size between those of the positive electrode active materials lithium-containing transition metal oxide represented by the (A) and (B). following formula (1): The content of the positive electrode active material (B) having the Smallest average particle size in the lithium-con Li, M.M.M.O. (1) taining transition metal oxides contained in the positive elec 65 wherein M' represents at least one transition metal element trode is preferably 5% by weight or more, more preferably selected from Co, Ni and Mn, M represents at least one metal 10% by weight or more, particularly preferably 20% by element selected from the group consisting of Mg, Ti, Zr, Ge. Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 24 of 90 PageID: 24
US 8,691.446 B2 11 12 Nb, Aland Sn, M represents an element other than Li, M'and Each of the positive electrode active material (B) repre M, and x, y, Z and V are numbers satisfying the following sented by the formula (1), and the lithium-containing transi equations respectively: 0.97sXs 1.02, 0.8sy<1.02, tion metal oxides other than the positive electrode active 0.002. US 8,691.446 B2 13 14 preferably less than 0.5% by mole, more preferably less than transition metal oxide(s), respectively, the element M is an 0.2% by mole, particularly preferably 0.1% by mole. element other than Li, M' and M. The positive electrode Also, when the content of Ti, Zr, Ge, Nb, Aland/or Sn is too active material (B) and the other lithium-containing transition large in the positive electrode active material (A), the effect to metal oxides may each contain the M in an amount such that increase the capacity of the battery may not be sufficient. the advantageous effects of the present invention are not Thus, when the oxide contains Ti, Zr, Ge and/or Nb, the total impaired, or they may contain no M. content thereof is preferably less than 0.3% by mole, more Examples of the element M include alkali metals other preferably less than 0.1% by mole, particularly preferably than Li (e.g., Na, K and Rb), alkaline earth metals other than less than 0.05% by mole based on the content of M'. When the Mg (e.g., Be, Ca,Sr and Ba), Group IIIa metals (e.g., Sc., Y. oxide contains Al and/or Sn, the total amount thereof is pref 10 La), Group IVa metals other than Ti and Zr (e.g., Hf), Group erably less than 0.5% by mole, more preferably less than Va metals other than Nb (e.g., V and Ta), Group VIa metals 0.2% by mole, particularly preferably less than 0.1% by mole (e.g., Cr, Mo and W), Group VIIb metals other than Mn (e.g., based on the content of M'. Tc and Re), Group VIII metals other than Co and Ni (e.g., Fe, Furthermore, when the lithium-containing transition metal Ru, and Rh), Group Ib metals (e.g., Cu, Ag and Au), Group oxide other than the positive electrode active materials (A) 15 IIIb metals other than Zn and Al (e.g., B, Ca and In), Group and (B) is used, the content of Mg in the other metal oxide is IVb metals other than Sn and Pb (e.g., Si), P and Bi. preferably at least 0.01% by mole, more preferably at least The metal element M contributes to animprovement in the 0.05% by mole, particularly preferably at least 0.07% by stability of the lithium-containing transition metal oxides. mole, based on the amount of the metal element M', from the However, when the content thereof is too large, a function of view point of more effectively attaining the effects of Mg. storing and releasing Li ions is impaired so that the battery When the lithium-containing transition metal oxide other characteristics may be decreased. Since the positive electrode than the positive electrode active materials (A) and (B) con active material (B) having the Smallest average particle size tains at least one metal element selected from Ti, Zr, Ge and has the particularly Small particle size and decreased stability, Nb, the total content thereof is at least 0.005% by mole, more it is preferable that the content of the element M, which is a preferably at least 0.008% by mole, particularly preferably at 25 stabilizing element, is somewhat high. In addition, since the least 0.01% by mole, based on the content of M', from the positive electrode active material (B) has the small particle viewpoint of more effectively attaining the effects of the use size and in turn the large Surface area, it exhibits a high of these metal elements. When the positive electrode active activity. Thus, the presence of the element M in the material material (A) contains Al and/or Sn, the total content thereof is (B) has less influence on the function of storing and releasing preferably 0.01% by mole or more, more preferably 0.05% by 30 Li ions. mole or more, particularly preferably 0.07% by mole or more In contrast, the lithium-containing transition metal oxides based on the content of M', from the viewpoint of more having relatively large particle sizes, that is, the lithium effectively attaining the effects of the use of these metal containing transition metal oxides other than the positive elements. electrode active material (B), have better stability than the However, again in the lithium-containing transition metal 35 positive electrode active material (B). Therefore, the former oxide other than the positive electrode active materials (A) metal oxides have less necessity to contain the element M and (B), when the content of Mg is too large, the load char than the positive electrode active material (B). Furthermore, acteristic of the battery tends to decrease. Therefore, the their function of storing and releasing Li ions is easily content of Mg is preferably less than 2% by mole, more impaired by the presence of the element M since the mate preferably less than 1% by mole, particularly preferably 0.5% 40 rials have the smaller surface area and the lower activity than by mole, most preferably 0.3% by mole, each based on the the positive electrode active material (B). content of M'. Accordingly, it is preferable that the content of the metal Again, in the lithium-containing transition metal oxide element M' in the positive electrode active material (B) is other than the positive electrode active materials (A) and (B), larger than that in the lithium-containing transition metal when the content of Ti, Zr, Ge, Nb, Al and/or Sn is too large 45 oxide(s) other than the positive electrode active material (B). in the positive electrode active material (A), the effect to That is, Zin the formula (1) is preferably larger than c in the increase the capacity of the battery may not be sufficient. formula (2) (ZDc). In particular, Z is at least 1.5 times, more Thus, when the oxide contains Ti, Zr, Ge and/or Nb, the total preferably at least 2 times, particularly preferably at least 3 content thereof is preferably less than 0.5% by mole, more times larger than c. When Z is much larger than c, the load preferably less than 0.25% by mole, particularly preferably 50 characteristics of the battery tend to decrease. Thus, Z is less than 0.15% by mole based on the content of M'. When the preferably less than 5 times as large as c', more preferably oxide contains Al and/or Sn, the total amount thereof is pref less than 4 times as large as c, particularly preferably less than erably less than 1% by mole, more preferably less than 0.5% 3.5 times as large as c. by mole, particularly preferably less than 0.3% by mole based When the three or more lithium-containing transition metal on the content of M'. 55 oxides having the different average particle sizes are con A method for including the metal element M in the posi tained in the positive electrode, there is no especial limitation tive electrode active material (B) or the other lithium-contain on the relationship of the element M content between the ing transition metal oxide(s) is not particularly limited. For positive electrode active material (A) having the largest aver example, the element M may be present on the particles of age particle size and the other lithium-containing transition the metal oxide, may be evenly present as a Solid Solution 60 metal oxides. Thus, the former may contain a larger amount inside the metal oxides, or may be unevenly present inside the of the element M than the latter, and vise versa, or the metal oxides with having a density distribution. Furthermore, element M' contents in the former and the latter may be the the element M may form a compound which in turn forms a same. In a more preferable embodiment, a metal oxide having layer on the particle surfaces. Preferably, the element M is a smaller average particle size contains a larger amount of the evenly present as a Solid Solution. 65 element M. In particular, when the three lithium-containing In the formulae (1) and (2) representing the positive elec transition metal oxides having different average particle sizes trode active material (B) and the other lithium-containing are used, the element M content in the positive electrode Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 26 of 90 PageID: 26 US 8,691.446 B2 15 16 active material (B) having the Smallest average particle size is content ratios of the metal elements of the positive electrode largest, that in lithium-containing transition metal oxide hav active material having different particle sizes may be mea ing the average particle size between those of the active Sured with an electron prove microanalyZerusing a mixture of materials (A) and (B) is second largest, and that in the positive positive electrode active materials having a known mixing electrode active material (A) having the largest average par ratio as a standard sample. Alternatively, the positive elec ticle size is Smallest. trode is treated with a suitable solvent such as N-methyl-2- When two or more lithium-containing transition metal pyrrolidone (NMP) to separate the active material particles oxides are used, the oxides having different average particle from the positive electrode and settled out in the solvent, sizes may have the same composition of elements, or different followed by washing and drying. Then, the particle size dis compositions of elements between them. When the lithium 10 tribution of the recovered particles is measured and the peak containing transition metal oxides according to the present separation of the particle size distribution curve is carried out. invention are the above-mentioned positive electrode active When the inclusion of two or more particles having different materials (A) and (B), the following combination may be particle sized is confirmed, the particles are classified into a used: a combination of the positive electrode active material larger one and a smaller one, and the contents of the metal (A) consisting of LiCoooosMgoooosTio-ooo.4AloooosC2, and 15 elements in each particle group are measured by the ICP the positive electrode active material (B) consisting of atomic emission spectroscopy. LiCoo.334Nio.33Mno.33 Mgoloo24Ti.o.ool2Alooo24O2. Herein, the contents of the metal elements in the positive The positive electrodeactive material, namely, the lithium electrode active material may be measured by the ICP atomic containing transition metal oxide used according to the emission spectroscopy as follows: about 5 g of the active present invention is formed through a certain synthesizing material is precisely weighed and charged in a 200 ml beaker. process and a certain battery producing process. For example, Then, 100 ml of aqua regia is added, and the mixture is for the preparation of lithium-containing transition metal concentrated by heating to a liquid volume of about 20 to 25 oxides which contain Co as the transition metal element M' ml. After cooling, the mixture is filtrated through a quantita and have different average particle sizes, firstly, a solution of tive filter paper (No. 5B available from Advantec MFS, Inc.) an alkali Such as NaOH is dropwise added to an acidic aque 25 to separate the solids. The filtrate and washing liquid are ous Solution containing Co to precipitate Co(OH). In order to charged in a 100 ml measuring flask and diluted to a specific homogeneously precipitate Co(OH), Co may be coprecipi Volume. Then, the contents of the metal elements in the solu tated with a different element, and then the coprecipitated tion are measured with a sequential type ICP analyzer (IPIS material is calcined to obtain COO. The particle size of the 1000 manufactured by Nippon Jarrel-Ash Co., Ltd.). precipitates can be adjusted by controlling the period for 30 When the content (I) of at least one metal element selected forming the precipitates. The particle size of COO after from the group consisting of Mg, Ti, Zr, Ge, Nb, Al and Sn in calcination is also controlled by the particle size of the pre the transition metal oxidehaving the smallest average particle cipitate at this time. size and a content (II) of the same metal element as one with When the positive electrode active material is synthesized, which the content (I) in the lithium-containing transition conditions such as a mixing condition, calcination tempera 35 metal oxide other than one having the Smallest average par ture, calcination atmosphere, calcination time, starting mate ticle size are measured by the ICP atomic emission spectros rials, and also battery fabrication conditions are Suitably copy described above, the ratio of the content (I) to the con selected. With regard to the mixing condition in the synthesis tent (II) corresponds to the relationship between Z in the of the positive electrode active material, preferably, for formula (I) and c in the formula (2). The ratio of the content (I) example, ethanol or water is added to the powdery starting 40 to the content (II) is preferably at least 1.5, more preferably at materials, and then mixed in a planetary ball mill for 0.5 hour least 2, particularly preferably at least 3. Since the load char or longer. More preferably, ethanol and water are mixed at a acteristics of the battery tend to decrease when Z is much volume ratio of 50:50, and the mixture is agitated in a plan larger than c, the ratio of the content (I) to the content (II) is etary ball mill for 20 hours or longer. Through this mixing preferably less than 5, more preferably less than 4, particu step, the powdery starting materials are sufficiently commi 45 larly preferably less than 3.5. nuted and mixed to prepare a homogeneous dispersion. The The positive electrode used in the present invention is dispersion is dried with a spray drier or the like while keeping formed by, for example, a method described below. Firstly, if homogeneity. The calcination temperature is preferably from necessary, an electric conductive aid (e.g., graphite, carbon 750 to 1,050° C., more preferably from 950 to 1,030°C. The black, acetylene black, etc.) is added to the lithium-contain calcination atmosphere is preferably an air. The calcination 50 ing transition metal oxide used as a positive electrode active time is preferably from 10 to 60 hours, more preferably from material. Furthermore, to the mixture, a binder (e.g., polyvi 20 to 40 hours. nylidene fluoride, poly tetrafluoroethylene, etc.) is added to In the preparation of the positive electrode active material, prepare a positive electrode mixture. A solvent is used to LiCO is preferably used as a lithium source. As the sources formulate this positive electrode mixture in the form of a of other metal such as Mg, Ti, Ge, Zr, Nb, Aland Sn, preferred 55 paste. The binder may be mixed with the positive electrode are nitrates or hydroxides of these metals, or oxides thereof active material and the like after the binder is dissolved in a having a particle size of 1 um or less. It is preferable to use the Solvent. In this way, the paste containing the positive elec coprecipitate of the hydroxides since the different elements trode mixture is prepared. The resultant paste is applied to a are uniformly distributed in the active material. positive electrode current collector made of an aluminum foil The contents of the metal elements in the positive electrode 60 or the like, and then dried to form a positive electrode mixture active materials are measured by the ICP atomic emission layer. If necessary, the layer is pressed to obtain a positive spectroscopy or the like. The content of lithium can be mea electrode. When the positive electrode active material com Sured by an atomic absorption analysis. In the state of a prises two or more lithium-containing transition metal oxides positive electrode, it is difficult to separately measure the having the different average particle sizes, for example, the contents of the metal elements in each of the positive elec 65 positive electrode active materials (A) and (B), they are mixed trode active material having a larger particle size and one at a predetermined ratio, and then the electric conductive aid having a smaller particle size. Therefore, the contents or and the binder are added to the mixture to prepare a positive Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 27 of 90 PageID: 27 US 8,691.446 B2 17 18 electrode mixture, which is used in the Subsequent steps. potential of lithium, and therefore the voltage of the positive However, the method for producing the positive electrode is electrode can be conveniently calculated as a Voltage obtained not limited to the above-mentioned method, and may be any by adding 0.1 V to the battery voltage. Consequently, the other method. charge Voltage of the positive electrode is easily controlled. The thickness of the positive electrode mixture layer is Preferably, graphite has such a form in that a lattice spacing preferably from 30 to 200 um, and the thickness of the current do of the (002) planes is 0.338 nm or less, since the negative collector used in the positive electrode is preferably from 8 to electrode or a negative electrode mixture layer, which will be 20 um. explained later, has a higher density as the crystallinity is In the positive electrode mixture layer, the content of the higher. However, when the lattice spacing doo is too large, the lithium-containing transition metal oxides as the active mate 10 high density negative electrode may decrease the discharge rials is preferably 96% by weight or more, more preferably characteristic or the load characteristic of the battery. Thus, 97% by weight or more, particularly preferably 97.5% by the lattice spacing doo is preferably 0.335 nm or more, more weight or more, while it is preferably 99% by weight or less, preferably 0.3355 nm or more. more preferably 98% by weight or less. The content of the The crystal size of the graphite in the c axis direction (Lc) binder in the positive electrode mixture layer is preferably 1% 15 is preferably 70 nm or more, more preferably 80 nm or more, by weight or more, more preferably 1.3% by weight or more, particularly preferably 90 nm or more. As the Lc is larger, the particularly preferably 1.5% by weight or more, while it is charging curve becomes flat so that the Voltage of the positive preferably 4% by weight or less, more preferably 3% by electrode is easily controlled and also the capacity can be weight or less, particularly preferably 2% by weight or less. made large. When the Lc is too large, the battery capacity The content of the electric conductive aid in the positive tends to decrease with the high-density negative electrode. electrode mixture layer is preferably 1% by weight or more, Thus, the Lc is preferably less than 200 nm. more preferably 1.1% by weight or more, particularly pref Furthermore, the specific surface area of the graphite is erably 1.2% by weight or more, while it is preferably 3% by preferably 0.5 m/g or more, more preferably 1 m/g or more, weight or less, more preferably 2% by weight or less, particu particularly preferably 2 m/g or more, while it is preferably larly preferably 1.5% by weight or less. 25 6 m/g or less, more preferably 5 m/g or less. Unless the When the content of the active material in the positive specific Surface area of the graphite is somewhat large, the electrode mixture layer is too small, the capacity cannot be characteristics tend to decrease. When the specific surface increased and also the density of the positive electrode mix area is too large, the graphite easily reacts with the electrolyte ture layer cannot be increased. When this content is too large, and Such a reaction may have influences on the properties of the resistance may increase or the formability of the positive 30 the battery. electrode may be impaired. When the binder content in the The graphite used in the negative electrode is preferably positive electrode mixture layer is too large, the capacity may made of natural graphite. More preferred is a mixture of two hardly be increased. When this content is too small, the adhe or more graphite materials having different Surface crystal sion of the layer to the current collector decreases so that the linity to achieve the high density of the negative electrode. powder may drop off from the electrode. Thus, the above 35 Since natural graphite is inexpensive and achieves a high mentioned preferable ranges are desirable. Furthermore, capacity, the negative electrode with a high cost performance when the content of the electric conductive aid in the positive can be produced. Usually, when natural graphite is used, the electrode mixture layer is too large, the density of the positive battery capacity is easily decreased as the density of the electrode mixture layer may not be made Sufficiently high so negative electrode is increased. However, the decrease in the that the capacity may hardly be increased. When this content 40 battery capacity can be suppressed by mixing the natural is too small, the Sufficient electric conduction through the graphite with a graphitehaving a reduced Surface crystallinity positive electrode mixture layer is not attained so that the by a Surface treatment. charge-discharge cycle characteristic or the load characteris The surface crystallinity of specific graphite can be deter tic of the battery may deteriorated. mined by the Raman spectrum analysis. When the R value of It is essential for the nonaqueous secondary battery of the 45 the Raman spectrum (R-Iso/Isso, that is, the ratio of the present invention to have the nonaqueous electrolyte and the Raman intensity around 1350 cm to that around 1580 cm) positive electrode, which are explained above, and thus there is 0.01 or more, where the Raman spectrum is measured with is no specific limitation on other elements or structure of the graphite which has been excited with an argon laser having a battery. The battery of the present invention may adopt vari wavelength of 514.5 nm, the surface crystallinity of the spe ous elements and structures, which are commonly adopted in 50 cific graphite is slightly lower than that of natural graphite. the conventional nonaqueous secondary batteries in the State Thus, with the graphite having a Surface crystallinity of art. decreased by the surface treatment, the R value is preferably The negative electrode active material in the negative elec 0.01 or more, more preferably 0.1 or more, while it is prefer trode may be any material that can be doped and de-doped ably 0.5 or less, more preferably 0.3 or less. The content of the with Li ions. Examples thereof are carbonaceous materials 55 graphite having a surface crystallinity decreased by Surface Such as graphite, pyrolytic carbons, cokes, glassy carbons, treatment is preferably 100% by weight of the whole graphite burned bodies of organic polymers, mesocarbon microbeads, in order to increase the density of the negative electrode. carbon fibers and activated carbon. In addition, the following However, in order to prevent the decrease of the battery materials can also be used as the negative electrode active capacity, the content of such graphite is preferably 50% by material: alloys of Si, Sn, In or the like, oxides of Si, Snor the 60 weight or more, more preferably 70% by weight or more, like that can be charged and discharged at a low Voltage near particularly preferably 85% by weight or more of the whole a voltage at which Li can be charged and discharged, and graphite. nitrides of Li and Co such as Li CoolN. Graphite can be When the average particle size of the graphite is too small, partially substituted with a metal, a metal oxide or the like that an irreversible capacity increases. Thus, the average particle can be alloyed with Li. When graphite is used as the negative 65 size of the graphite is preferably 5 um or more, more prefer electrode active material, the voltage when the battery is fully ably 12 um or more, particularly preferably 18 um or more. charged can be regarded as about 0.1 V with reference to the From the viewpoint of the increase of the capacity of the Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 28 of 90 PageID: 28 US 8,691.446 B2 19 20 negative electrode, the average particle size of the graphite is In the negative electrode mixture layer, the content of the 30 um or less, more preferably 25 um or less, particularly binder or binders is preferably 1.5% by weight or more, more preferably 20 um or less. preferably 1.8% by weight or more, particularly preferably The negative electrode may be produced by the following 2.0% by weight or more of the layer, while it is preferably less method, for example: The negative electrode active material than 5% by weight, less than 3% by weight, less than 2.5% by and an optional a binder and/or other additives are mixed to weight. When the amount of the binder in the negative elec prepare a negative electrode mixture, and the mixture is dis trode mixture layer is too large, the discharge capacity of the persed in a solvent to prepare a paste. Preferably, the binder is battery may decrease. When the amount is too small, the dissolved in a solvent prior to mixing with the negative elec adhesion between the particles decreases. The content of the trode active material, and then mixed with the negative elec 10 negative electrode active material in the negative electrode trode active material and so on. The paste containing the mixture layer is preferably more than 95% by weight and negative electrode mixture is applied to a negative electrode 98.5% by weight or less. current collector made of a copper foil or the like, and then In the present invention, a separator used in the present dried to form a negative electrode mixture layer. The layer is invention preferably has a thickness of 5 um or more, more pressed to obtain a negative electrode. However, the method 15 preferably 10 um or more, particularly preferably 12 um or for producing the negative electrode is not limited to the more, while it is preferably less than 25um, more preferably above-mentioned method, and may be any other method. less than 20 Lum, particularly preferably less than 18 um, from The density of the negative electrode mixture layer after the viewpoint of imparting the directionality of the tensile pressing is preferably 1.70 g/cm or more, more preferably strength to the separator, keeping good insulating properties 1.75 g/cm or more. Based on the theoretical density of graph and reducing the thermal shrinkage of the separator. The gas ite, the upper limit of the density of the negative electrode permeability of the separator is preferably 500 second/100 mixture layer formed using graphite is 2.1 to 2.2 g/cm. The mL or less, more preferably 300 second/100-mL or less, density of the negative electrode mixture layer is preferably particularly preferably 120 second/100-mL or less. As the gas 2.0 g/cm or less, more preferably 1.9 g/cm or less from the permeability of the separator is Smaller, the load characteris viewpoint of the affinity with the nonaqueous electrolyte. It is 25 tic is made better but an inside short-circuit is more easily preferable to press the negative electrode plural times since caused. Thus, the gas permeability is preferably 50 second/ the negative electrode can be uniformly pressed. 100-mL or more. Here, a gas permeability is measured The binder used in the negative electrode is not particularly according to JISP8117. As the thermal shrinkage factor of the limited. For the increase of the content of the active material separator in the transverse direction (TD) is Smaller, an inside to increase the capacity, the amount of the binder is preferably 30 short-circuit is less easily caused when the temperature of the made as small as possible. To this end, the binder is preferably battery rises. Thus, the thermal shrinkage factor in TD of the a mixture of an aqueous resin which can be dissolved or separator is as small as possible. The thermal shrinkage factor dispersed, and a rubbery polymer, since the use of only a in TD is preferably 10% or less, more preferably 5% or less. Small amount of the aqueous resin can contribute to the dis In order to restrain the thermal shrinkage of the separator, it is persion of the graphite and thus prevents the delamination of 35 preferable to thermally treat the separator in advance at a the negative electrode mixture layer from the current collec temperature of about 100 to 125° C. The separator having tor caused by the expansion and contraction of the electrode such a thermal shrinkage factor is preferably combined with in the charge-discharge cycles. the positive electrode materials according to the present Examples of the aqueous resins include cellulose resins invention to fabricate a battery, since the behaviors of the Such as carboxymethylcellulose, and hydroxypropylcellu 40 battery at high temperature become stable. lose, and polyvinylpyrrolidone, polyepichlorohydrin, polyvi The thermal shrinkage factor in TD of the separator means nylpyridine, polyvinyl alcohol, polyether resins such as poly the shrinkage factor of a portion thereof that most largely ethylene oxide and polyethylene glycol, etc. Examples of the shrinks in TD when the separator having a size of 30 mm rubbery polymers include latex, butyl rubber, fluororubber, square is allowed to stand at 105° C. for 8 hours. styrene-butadiene rubber, nitrile-butadiene copolymer rub 45 With regard to the strength of the separator, a tensile ber, ethylene-propylene-diene copolymer (EPDM), polyb strength in the machine direction (MD) is preferably 6.8x utadiene, etc. From the viewpoint of the dispersibility of the 10 N/m or more, more preferably 9.8x107 N/m or more. The graphite particles and the prevention of delamination of the tensile strength in TD is preferably smaller than that in MD. layer, it is preferable to use a cellulose ether compound Such The ratio of the tensile strength in TD to that in MD (tensile as carboxymethylcellulose together with abutadiene copoly 50 strength in TD/tensile strength in MD) is preferably 0.95 or mer rubber such as a styrene-butadiene rubber. It is particu less, more preferably 0.9 or less, while it is preferably 0.1 or larly preferable to use carboxymethylcellulose together with more. The transverse direction means a direction perpendicu a butadiene copolymer rubber Such as a styrene-butadiene lar to the direction in which the film resin for the production copolymer rubber or a nitrile-butadiene-copolymer rubber. of the separator is wound up, that is, the machine direction. The cellulose ether compound such as carboxymethylcellu 55 The puncture strength of the separator is preferably 2.0 N lose mainly has a thickening effect on the paste containing the or more, more preferably 2.5 N or more. As this value is negative electrode mixture, while the rubbery polymer such higher, the battery is less easily short-circuited. Usually, how as the styrene-butadiene copolymer rubber has a binding ever, the upper limit thereof is substantially determined by the effect on the negative electrode mixture. When the cellulose material of the separator. In the case of a separator made of ether compound Such as carboxymethylcellulose and the rub 60 polyethylene, the upper limit of the puncture strength is about bery polymer Such as the styrene-butadiene copolymer rub 10 N. Here, a puncture strength is measured by cutting a ber are used in combination, the weight of the former to the sample piece of 50 mmx50 mm from a separator, clamping latter is preferably from 1:1 to 1:15. the sample piece with jigs at the edges of 5 mm, puncturing The thickness of the negative electrode mixture layer is the sample piece with a needle having a tip end with a radius preferably from 40 to 200 um. The thickness of the current 65 of 0.5 mm at a rate of 2 mm/sec., and measuring a maximum collector used in the negative electrode is preferably from 5 to load before the puncture of the sample piece as a puncture 30 um. strength. Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 29 of 90 PageID: 29 US 8,691.446 B2 21 22 When a conventional nonaqueous secondary battery is stylus-operated personal computer, a pocket personal com charged at a high positive electrode voltage of 4.35 V or puter, a notebook word processor, a pocket word processor, an higher with reference to the potential of lithium and is dis electronic book player, a cellular phone, a codeless handset, a charged to a final Voltage higher than 3.2 V, the crystalline pager, a portable terminal, a portable copier, an electrical structure of the positive electrode active material decays to notebook, an electronic calculator, a liquid crystal television decrease the capacity or to induce heating of the battery due to set, an electric shaver, an electric power tool, an electronic the deterioration of the thermal stability. Thus, the battery translating machine, an automobile telephone, a transceiver, a may not be practically used. When a positive electrode active Voice input device, a memory card, a backup power source, a material to which a different element such as Mg or Ti is tape recorder, a radio, a headphone stereo, a handy printer, a added is used, the decrease of the safety or of the capacity 10 handy cleaner, a portable CD player, a MD player, a portable over charge-discharge cycles can be suppressed, but the digital audio player, a video movie, a navigation system, a degree of Suppression is not sufficient. Moreover, the filling refrigerator, an air conditioner, a television, a stereo, a water of the positive electrode is insufficient so that the battery heater, a microwave oven, a dishwasher, a washing machine, easily expands. a drying machine, a game equipment, a lighting equipment, a In contrast, the battery of the present invention having the 15 toy, a sensor equipment, a load conditioner, a medical structure explained above is a nonaqueous secondary battery machine, an automobile, an electric vehicle, a golf cart, an which improves the capacity, the charge-discharge cycle electrically-powered cart, a security system, a power storing characteristic, the safety and the Suppression of expansion of system, or the like. The battery can be used not only for the the battery (storage characteristics). These advantageous consumer applications but also for aerospace applications. effects can be attained at a usual charging volt (a battery The capacity-increasing effect of the present invention is voltage of 4.2V). Furthermore, when the positive electrode is enhanced, in particular, in Small-sized portable devices. Thus, charged up to a high voltage of 4.35 V with reference to the the battery of the present invention is used in a portable device potential of lithium (i.e., a battery voltage of 4.25 V) and then desirably having a weight of 3 kg or less, more desirably 1 kg the discharge of the battery is terminated at a high Voltage, or less. The lower limit of the weight of the portable device is that is, a battery voltage of 3.2 V or higher, the crystalline 25 not particularly limited. However, the lower limit is desirably structures of the positive electrode active materials are very a value equal to the weight of the battery, for example, 10g or stable so that the decrease of the capacity or thermal stability more in order to attain the advantageous effects to some is prevented. degree. Moreover, the positive electrode active material of any conventional nonaqueous secondary battery generates a low 30 EXAMPLES average Voltage. Therefore, when a charge-discharge cycle test is repeated under a condition that the discharge final The present invention will be described in detail with ref voltage of a unit cell is 4.35 V or higher with reference to the erence to the following Examples; however, the Examples do potential of lithium, the positive electrode is doped or not limit the scope of the present invention. Thus, modifica dedoped with a large amount of Li ions. This situation is 35 tions of the examples are encompassed by the scope of the analogous to a case where the battery is subjected to a charge present invention as long as the modifications do not depart discharge cycle test under an overcharge condition. Under from the subject matter of the present invention, which has Such a severe condition, any conventional positive electrode been described above or will be described hereinafter. active material cannot maintain its crystalline structure so as to cause disadvantages Such that the thermal stability declines 40 Example 1 or the charge-discharge cycle life is shortened. To the con trary, the use of the positive electrode active material accord Production of Positive Electrode ing to the battery of the present invention can overcome Such disadvantages of the conventional positive electrode active The lithium-containing positive electrode materials, material. Thus, the present invention provides a nonaqueous 45 LiCuo.99s.MgoooosTio-ooo-AloooosC2 (average particle size: secondary battery which can be reversibly charged and dis 12 um) as a positive electrode active material (A), and charged even at a high Voltage. Such as a Voltage of 4.35 to 4.6 LiCuo.994Mgooo-Tioloo. 2Alooo-O2 (average particle size: 5 V with reference to the potential of lithium, when the battery um) as a positive electrodeactive material (B) at a weight ratio is fully charged. of 65:35 were mixed. Then, 97.3 parts by weight of the Here, the “fully charged’ means that a battery is charged by 50 mixture and 1.5 parts by weight of a carbonaceous material as charging it at a constant current of 0.2C to a specific Voltage an electric conductive aid were charged in a Volumetric feeder and then charging it at a constant Voltage at the specific as a device for Supplying powder. An amount of a 10 wt.% Voltage until the total charging time of the constant current solution of polyvinylidene fluoride (PVDF) in N-methyl-2- charging and the constant Voltage charging reaches 8 hours. pyrrolidone (NMP) to be supplied to the feeder was adjusted When the battery of the present invention has a graphite 55 to control a solid content in the mixture constantly at 94% by negative electrode (i.e. a negative electrode containing graph weight during kneading. While the amount of the mixed ite as a negative electrode active material) which has a Voltage materials Supplied in a unit time was controlled to a prede of 0.1 V with reference to the lithium potential when the termined amount, the materials were Supplied in a biaxial battery is fully charged, the charging of the battery to a battery kneading extruder and then kneaded. In this way, a paste Voltage of 4.45 V or higher is assumed as a charging of the 60 containing the positive electrode mixture was prepared. battery in which the voltage of the positive electrode is sub Separately, the positive electrode active materials (A) and stantially 4.35 V or higher. (B) were dissolved in aqua regia and the ratio of the elements The nonaqueous secondary battery of the present invention contained in the materials (A) and (B) was measured by the has characteristics including a high Voltage, a high capacity ICP atomic emission spectroscopy, the results of which con and a high safety. By making use of Such characteristics, the 65 firmed that they had the above elementary compositions. nonaqueous secondary battery of the present invention can be The resultant paste was charged in a planetary mixer, and used as a power source of a notebook personal computer, a then a 10 wt.% solution of PVDF in NMP, and NMP were Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 30 of 90 PageID: 30 US 8,691.446 B2 23 24 added to dilute the paste, thereby adjusting the viscosity of the 10 um, and then dried to form negative electrode mixture paste at a level sufficient for application. This diluted paste layers. The resultant sheet was pressed with a roller until the containing the positive electrode active material mixture was density of the negative electrode mixture layers became 1.75 passed through a 70-mesh net to remove large Substances. g/cm. The resultant sheet was then cut out in a predetermined Thereafter, the paste was uniformly applied to both surfaces size. Thereafter, a lead member made of nickel was welded to of a positive electrode current collector made of an aluminum the cut piece to form a sheet-form negative electrode. foil with a thickness of 15um, and then dried to form film Preparation of Nonacqueous Electrolytic Solution form positive electrode mixture layers. In the dried positive An amount of LiPF was dissolved in a mixed solvent of electrode mixture layers, the weight ratio of the positive elec methylethyl carbonate, diethyl carbonate and ethylene car trode active material/the electric conduction aiding agent/ 10 bonate mixed at a Volume ratio of 1:3:2 to attain a concentra PVDF was 97.3:1.5:1.2. Thereafter, the resultant sheet was tion of 1.4 mol/L. To this solution, 0.2% by weight of succi pressed and cut out in a predetermined size. To the cut piece, nonitrile and 3% by weight of vinylene carbonate were added a lead member made of aluminum was welded to form a to prepare a nonaqueous electrolytic Solution. sheet-form positive electrode. The density of the pressed Production of Nonacqueous Secondary Battery positive electrode mixture layers (the density of the positive 15 The positive electrode and the negative electrode were electrode) was 3.86 g/cm. The thickness of the positive elec spirally wound with interposing, therebetween, a separator trode mixture layers (the total thickness of the layers on both made of a microporous polyethylene film (porosity: 53%, the Surfaces, i.e., the thickness obtained by Subtracting the tensile strength in MD: 2.1x10 N/m, tensile strength in TD: thickness of the aluminum foil layer of the positive electrode 0.28x10 N/m, thickness: 16 Jum, gas permeability: 80 sec current collector from the total thickness of the positive elec onds/100-mL, thermal shrinkage factor after being kept at trode) was 135um. 105° C. for 8 hours: 3%, puncture strength: 3.5 N (360 g)), to The particle size distribution of the mixture of the positive form an electrode body having a spiral structure. Thereafter, electrode active materials (A) and (B) was measured by a the electrode body was pressed to form a flat-shaped electrode MICROTRAC particle size analyzer (HRA 9320 available body and inserted into a box-shaped battery case made of an from NIKKISO Co., Ltd.). In the particle size distribution 25 aluminum alloy. The positive and negative lead members curve, two peaks were found at an average particle size of were welded and a cover plate was laser welded to the edge about 5um and 12um, respectively. d, was larger thand, and portion of an opening of the battery case. Then, the nonaque d/d was 1.4. ous electrolytic Solution prepared in the above was poured In the positive electrode active material (A), the amount of into the battery case through an inlet made in the cover plate. Mg was 0.08% by mole, that of Ti was 0.04% by mole, and 30 The nonaqueous electrolytic solution was Sufficiently infil that of Al was 0.08% by mole, each based on the amount of trated into the separator and the like. Thereafter, the battery Co. An electron prove X-ray microanalyzer (EMPA 1600 was partially charged, and gas generated during the partial manufactured by Shimadzu Corporation) was used to mea charging was discharged. Then, the inlet was sealed up to sure the concentration of the metal element M in cross sec make the battery airtight. Thereafter, the battery was charged tions of the particles. As a result, no difference in the concen 35 and aged to yield a rectangular nonaqueous secondary battery tration of each of Mg, Ti and Al was observed between the having a structure as shown in FIGS. 1A and 1B and an Surface portion and the core portion. external appearance as shown in FIG. 2, and a width of 34.0 In the positive electrode active material (B), the amount of mm, a thickness of 4.0 mm, and a height of 50.0 mm. Mg was 0.24% by mole, that of Ti was 0.12% by mole, and Here, the battery shown in FIGS. 1A, 1B and 2 will be that of Al was 0.24% by mole, each based on the amount of 40 explained. The positive electrode 1 and the negative electrode Co. The concentration of the metal element M in the cross 2 are spirally wound with interposing the separator 3 therebe sections of the particles was measured in the same manner as tween, as described above, and the spirally wound electrode in the case of the positive electrode active material (A). As a body is pressed in a flatform to form the electrode laminate 6 result, no difference in the concentration of each of Mg, Ti having a flat spiral structure. The laminate 6 together with a and Al was observed between the surface portion and the core 45 nonaqueous electrolytic solution is contained in the box portion. shaped battery case 4. For simplicity, in FIG. 1, metal foils as With regard to the contents of the metal elements M, the current collectors used to form the positive electrode 1 and the molar contents of Mg, Ti and Al in the positive electrode negative electrode 2, and the electrolytic Solution are not active material (B) were 3 times larger, 3 times larger and 3 depicted. times larger, respectively, than those in the positive electrode 50 The battery case 4 is made of an aluminum alloy, and active material (A). constitutes a main part of the exterior package of the battery. Production of Negative Electrode This battery case 4 also functions as a positive electrode As negative electrode active materials, 70 parts by weight terminal. The insulator 5 made of a polytetrafluoroethylene of a graphite type carbonaceous material (a) (purity: 99.9% or sheet is arranged on the inside bottom of the battery case 4. more, average particle size: 18 um, doo: 0.3356 nm, size of 55 The positive electrode lead member 7 and the negative elec the crystallite in the c axis direction (Lc): 100 nm, R value of trode lead member 8 connected to one end of the positive the Raman spectrum: 0.18) and 30 parts by weight of a graph electrode 1 and that of the negative electrode 2, respectively, ite type carbonaceous material (b) (purity: 99.9% or more, are taken out from the electrode laminate 6 having the flat average particle size: 21 um, doo: 0.3363 nm, size of the spiral structure. The terminal 11 made of stainless steel is crystallite in the c axis direction (Lc): 60 nm, R value of the 60 attached to the cover plate 9 made of aluminum for closing the Raman spectrum: 0.11) were mixed. Then, 98 parts by weight opening of the battery case 4 with interposing the insulation of the graphite mixture, 1 part by weight of carboxymethyl packing 10 made of polypropylene therebetween. The lead cellulose and 1 part by weight of a styrene-butadiene rubber plate 13 made of stainless steel is attached to this terminal 11 were mixed in the presence of water to prepare a paste con with interposing the insulator 12 therebetween. taining negative electrode mixture. This paste was uniformly 65 The cover plate 9 is inserted into the opening of the battery applied to both surfaces of a negative electrode current col case 4, and their joining portions are welded to each other, lector made of a strip-form copper foil having a thickness of thereby closing the opening of the battery case 4 to make the Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 31 of 90 PageID: 31 US 8,691.446 B2 25 26 interior of the battery airtight. In the battery shown in FIGS. times larger and 3 times larger, respectively, than those in the 2A and 2B, the inlet 14 for pouring the electrolytic solution is positive electrode active material (A). made in the cover plate 9, and the inlet 14 is welded and sealed up by, for example, laser welding, with inserting a sealing Example 7 member (not shown). In this way, the air-tightness of the battery is kept. Accordingly, in the case of the battery shown A nonaqueous secondary battery was fabricated in the in FIGS. 2A, 2B and 3, the electrolytic solution pouring inlet same manner as in Example 1 except that the weight ratio of 14 is actually composed of the inlet 14 and the sealing mem the positive electrode active material (A) to the positive elec ber, but the inlet 14 is illustrated as such without a sealing trode active material (B) was changed to 90:10. The density of member in order to make the figure simple. The explosion 10 the positive electrode mixture layers (positive electrode) after proof vent 15 is made in the cover plate 9. pressing was 3.75 g/cm. In the battery 1 of Example 1, the positive electrode lead member 7 is directly welded to the cover plate 9, whereby the Example 8 combination of the battery case 4 and the cover plate 9 func 15 A nonaqueous secondary battery was fabricated in the tions as a positive electrode terminal. The negative electrode same manner as in Example 1 except that a mixture of the lead member 9 is welded to the lead plate 13, and the negative positive electrode active material (A) consisting of electrode lead member 8 and the terminal 11 are made elec LiCuo.99s.MgoooosTio-ooo-AloooosC2 (average particle size: trically conductive through the lead plate 13, whereby the 12 um), and the positive electrode active material (B) consist terminal 11 functions as a negative electrode terminal. How ing of LiCuo-oo-Mgooo-Tioloo. 2Aloloo.4O2 (average particle ever, the functions of the positive and negative electrodes may size: 5 Lum) in a weight ratio of 50:50 was used as a positive be reversed in accordance with the material of the battery case electrode active material. The density of the positive elec 4, etc. trode mixture layers (positive electrode) after pressing was FIG. 2 is a perspective view schematically illustrating the 3.76 g/cm. With regard to the contents of the metal elements external appearance of the battery shown in FIGS. 1A and 1B. 25 M, the molar contents of Mg, Ti and Al in the positive FIG. 2 shows that the above-mentioned battery is a rectangu electrode active material (B) were 3 times larger, 3 times lar battery. Thus, FIG. 2 schematically shows the battery, and larger and 3 times larger, respectively, than those in the posi depicts the specific elements out of the constituting elements tive electrode active material (A). of the battery. 30 Example 9 Example 2 A nonaqueous secondary battery was fabricated in the A nonaqueous secondary battery was fabricated in the same manner as in Example 1 except that the positive elec same manner as in Example 1 except that glutaronitrile was trode active material (A) was changed to used in place of Succinonitrile. 35 LiCoooosMgoooosTio-ooo-SnoooosC2 (average particle size: 14 lum), and the positive electrode active material (B) was Example 3 changed to LiCuo.994Mgoloo.24Ti.o.o.o.12Snooo.4O2 (average particle size: 6 Lm). The density of the positive electrode A nonaqueous secondary battery was fabricated in the mixture layers (positive electrode) after pressing was 3.76 same manner as in Example 1 except that adiponitrile was 40 g/cm. With regard to the contents of the metal elements M, the molar contents of Mg, Ti and Sn in the positive electrode used in place of Succinonitrile. active material (B) were 3 times larger, 3 times larger and 3 Example 4 times larger, respectively, than those in the positive electrode active material (A). 45 A nonaqueous secondary battery was fabricated in the Example 10 same manner as in Example 1 except that the amount of succinonitrile was changed to 0.5% by weight. A nonaqueous secondary battery was fabricated in the same manner as in Example 1 except that the positive elec Example 5 50 trode active material (A) was changed to LiCuo.99s.Mgoooos Zroooo-Alooooso2 (average particle size: A nonaqueous secondary battery was fabricated in the 13 Lum) and the positive electrode active material (B) was same manner as in Example 1 except that the amount of changed to LiCuo.994Mgoloo.247mooo 12 Aloloo.24O2 (average Succinonitrile was changed to 1.0% by weight. particle size: 6 Lm). The density of the positive electrode 55 mixture layers (positive electrode) after pressing was 3.8 Example 6 g/cm. With regard to the contents of the metal elements M, the molar contents of Mg, Zr and Al in the positive electrode A nonaqueous secondary battery was fabricated in the active material (B) were 3 times larger, 3 times larger and 3 same manner as in Example 1 except that the positive elec times larger, respectively, than those in the positive electrode trode active material (A) was changed to 60 active material (A). LiCuosossMgoooosTioloo-O2 (average particle size: 12 Lum), and the positive electrode active material (B) was changed to Example 11 LiCuo.9964Mgooo-Tioloo.2O2 (average particle size: 5 Lum). The density of the positive electrode mixture layers (positive A nonaqueous secondary battery was fabricated in the electrode) after pressing was 3.79 g/cm. With regard to the 65 same manner as in Example 1 except that the positive elec contents of the metal elements M, the molar contents of Mg trode active material (A) was changed to and Ti in the positive electrode active material (B) were 3 LiCuo.99s.MgoooosGeoooo-AloooosC2 (average particle size: Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 32 of 90 PageID: 32 US 8,691.446 B2 27 28 12 um), and the positive electrode active material (B) was stored in a thermostatic chamber kept at 85°C. for 24 hours, changed to LiCuo 994Mgoloo.24Geoloo 12 Aloloo.4O2 (average removed from the chamber and kept standing at room tem particle size: 6 Lm). The density of the positive electrode perature for 4 hours. Again, the thickness T of the battery mixture layers (positive electrode) after pressing was 3.79 (after storage) was measured. Using the thicknesses of the g/cm. With regard to the contents of the metal elements M, battery before and after storage, a rate of change of the battery the molar contents of Mg, Ge and Al in the positive electrode thickness was calculated according to the following equation: active material (B) were 3 times larger, 3 times larger and 3 times larger, respectively, than those in the positive electrode Rate of change (%)=(T-T)/Tx100 active material (A). The results are shown in Table 1. 10 Example 12 TABLE 1 Discharge capacity A nonaqueous secondary battery was fabricated in the Example after Rate of change of same manner as in Example 1 except that the positive elec No. charge-discharge cycles battery thickness trode active material (A) was changed to 15 1 102 14.8 LiCoossa Nioss Mno.33 Mgoloo.24Ti.o.o.o. 2Alooo24O2 (average 2 102 13.2 particle size: 5 Lm). The density of the positive electrode 3 103 11.6 mixture layers (positive electrode) after pressing was 3.72 4 101 12.6 g/cm. With regard to the contents of the metal elements M, 5 99 9.8 6 103 15.3 the molar contents of Mg, Ti and Al in the positive electrode 7 102 15.6 active material (B) were 3 times larger, 3 times larger and 3 8 103 15.2 times larger, respectively, than those in the positive electrode 9 102 15.3 active material (A). 10 103 15.4 11 103 15.6 12 104 17.6 Comparative Example 1 25 C. 1 100 2SO A nonaqueous secondary battery was fabricated in the same manner as in Example 1 except that only As can be seen from the results in Table 1, the nonaqueous LiCuo.99s.MgoooosTio-ooo-AloooosC2 (average particle size: secondary batteries of Examples 1-12 according to the 12 um) was used as a positive electrode active material and no 30 present invention had the better discharge capacity, charge Succinonitrile was added to the nonaqueous electrolyte. The discharge cycle characteristics and storage characteristics density of the positive electrode mixture layers (positive elec than the nonaqueous secondary battery of Comparative trode) after pressing was 3.7 g/cm. This is a comparative Example 1. example using only a positive electrode active material hav The invention claimed is: ing a large particle size, that is, the positive electrode active 35 1. A nonaqueous secondary battery comprising: a positive material (A), among the positive electrode active materials electrode having a positive electrode mixture layer, a negative used in Example 1 and further no compound having at least electrode, and a nonaqueous electrolyte, two nitrile compound was used. wherein the positive electrode contains, as an active mate With the nonaqueous secondary batteries fabricated in rial, at least two lithium-containing transition metal Examples 1-12 and Comparative Example 1, the following 40 oxides having different average particle sizes, properties were evaluated: wherein said at least two lithium-containing transition Discharge Capacity After Charge-Discharge Cycles metal oxides having different average particle sizes have Each of the batteries fabricated in Examples and Compara different compositions of elements between them, tive Example was discharged to 3.0 V at 1 CmA at a room said lithium-containing transition metal oxide having the temperature, and charged to 4.2V at a constant current of 1 C 45 Smallest average particle size is a lithium-containing and then at a constant Voltage of 4.2 V until the total charge transition metal oxide represented by the formula (1): time reached 2.5 hours. Thereafter, the battery was dis charged at 0.2 CmA down to 3.0 V. Thereby, a discharge Li, M.M.M.O. (1) capacity of the battery was measured. Then, the above charge wherein M' represents at least one transition metal element discharge cycle was repeated five times, and the discharge 50 selected from Co, Ni and Mn, M represents Mg and at capacity after the fifth cycle was used to evaluate the dis least one metal element selected from the group consist charge capacity after the charge-discharge cycles. The results ing of Ti, Zr, Ge, Nb, Al and Sn, M represents an are shown in Table 1. In Table 1, the discharge capacity after element other than Li, M' and M, and x, y, z and v are the charge-discharge cycles obtained with each battery is numbers satisfying the equations respectively: shown as a relative value in relation to the discharge capacity 55 0.97sx<1.02, 0.8sy<1.02, 0.002. US 8,691.446 B2 29 30 wherein M' represents at least one transition metal element wherein M' represents at least one transition metal element selected from Co, Ni and Mn, M represents at least one selected from Co, Ni and Mn, M represents Mg and at metal element selected from the group consisting of Mg, least one metal element selected from the group consist Ti, Zr, Ge. Nb, Aland Sn, Mrepresents an element other ing of Ti, Zr, Ge, Nb, Al and Sn, M represents an than Li, M' and M, and a, b, c and d are numbers 5 element other than Li, M' and M, and a, b, c and d are satisfying the equations respectively: 0.97sa-1.02, numbers satisfying the equations respectively: 0.8sb-1,02, Oscs0.02, and 0 Exhibit 2 Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 35 of 90 PageID: 35 US00935.0019B2 (12) United States Patent (10) Patent No.: US 9,350,019 B2 Sakata et al. (45) Date of Patent: *May 24, 2016 (54) NONAQUEOUS SECONDARY BATTERY AND (58) Field of Classification Search METHOD OF USING THE SAME CPC ...... H01 M 4/505; H01M 4/60; H01 M 4/525 USPC ...... 429/188, 326,330, 331, 332, 200,339, (71) Applicant: Hitachi Maxell, Ltd., Osaka (JP) 429/307, 245, 231 (72) Inventors: Hideo Sakata, Osaka (JP); Fusaji Kita, See application file for complete search history. Osaka (JP); Kumiko Ishizuka, Osaka (JP) (56) References Cited (73) Assignee: HITACHI MAXELL, LTD., U.S. PATENT DOCUMENTS Ibaraki-shi, Osaka (JP) 4,302,518 A 11/1981 Goodenough et al. 4,668,595 A 5, 1987 Yoshino et al. (*) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 (Continued) U.S.C. 154(b) by 125 days. FOREIGN PATENT DOCUMENTS This patent is Subject to a terminal dis claimer. CN 1776938 A 5, 2006 JP 55-136131 A 10, 1980 (21) Appl. No.: 14/189.628 (Continued) (22) Filed: Feb. 25, 2014 OTHER PUBLICATIONS (65) Prior Publication Data A Japanese Office Action, dated Oct. 11, 2011, for Japanese Appli cation No. 2006-290637. US 2014/0178757 A1 Jun. 26, 2014 (Continued) Related U.S. Application Data (62) Division of application No. 1 1/976,566, filed on Oct. Primary Examiner — Kenneth Douyette 25, 2007, now Pat. No. 8,691.446. (74) Attorney, Agent, or Firm — Birch, Stewart, Kolasch & Birch, LLP (30) Foreign Application Priority Data (57) ABSTRACT Oct. 26, 2006 (JP) ...... 2006-290637 A nonaqueous secondary battery having a positive electrode (51) Int. Cl. having a positive electrode mixture layer, a negative elec HOLM 4/60 (2006.01) trode, and a nonaqueous electrolyte, in which the positive HOLM 4/505 (2010.01) electrode contains, as an active material, a lithium-containing (Continued) transition metal oxide containing a metal element selected from the group consisting of Mg, Ti, Zr, Ge, Nb, Al and Sn, (52) U.S. Cl. CPC ...... H0IM 4/505 (2013.01); H01 M 4/13 the positive electrode mixture layer has a density of 3.5 g/cm (2013.01); H0IM 4/131 (2013.01); H0IM or larger, and the nonaqueous electrolyte contains a com 4/133 (2013.01); pound having two or more nitrile groups in the molecule. (Continued) 5 Claims, 2 Drawing Sheets Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 36 of 90 PageID: 36 US 9,350,019 B2 Page 2 (51) Int. Cl. 2006/0134521 A1 6, 2006 Shima 2006, O1941 18 A1 8, 2006 Yew et al. Et; 38: 2006/0263690 A1 11/2006 Suhara et al. EY 7. 38: FOREIGN PATENT DOCUMENTS HOLM 4/36 (2006.01) JP 3-201368 A 9, 1991 HOLM 4/485 (2010.01) E. 1:23 A $2: HOLM 4/587 (2010.01) JP T-176322. A 7, 1995 HIM I/0525 (2010.01) JP 2001-167763. A 6, 2001 H0IM 10/0567 (2010.01) E. 38.73. A 358 HIM I/42 (2006.01) JP 2001-319652. A 11, 2001 HOIM IO/O569 (2010.01) JP 2002-216745. A 8, 2002 HOIM 4/O2 (2006.01) JP 2002-270238 A 9, 2002 JP 2003-217582. A 7, 2003 (52) U.S. Cl. JP 2004-179146 A 6, 2004 CPC ...... H0IM 4/364 (2013.01); H0IM 4/485 2004-296,098 A 10, 2004 (2013.01); H0IM 4/525 (2013.01); H0IM JP 2005-050582. A 2, 2005 4/587 (2013.01); H01 M 4/60 (2013.01); H0IM E. 2932, A 1339. 10/0525 (2013.01), HOLM 10/0567 (2013.01); , 2006-164742 A 6, 2006 H0IM 10/4235 (2013.01): HOIM 10/0569 2006-245001. A 9, 2006 (2013.01); HOIM 2004/021 (2013.01); Y02E JP 2007-042302. A 2, 2007 60/122 (2013.01); Y02T 10/701 1 (2013.01) WO WO 2004/03.0125 A1 4/2004 WO WO 2005/069423 A1 7/2005 WO WO 2005,117198 A1 12/2005 (56) References Cited WO WO 2006/091019 A1 8/2006 U.S. PATENT DOCUMENTS OTHER PUBLICATIONS 5.147.738 A 9/1992 Toyoguchi Chinese Office Action for Application No. 200710180385.4, dated 2002fOO3745.6 A1 3/2002 Hosoya Feb. 10, 2011. 2003, OO68555 A1 4/2003 Naruoka Japanese Office Action, dated May 17, 2013, for Japanese Patent 2004/001394.6 A1 1/2004 Abe et al. Application No. 2011-261150. 2005. O164082 A1 7/2005 Kishi et al. Machine Translation of JP 2005/050582 A, Kikuchi, Kazuhiro, Feb. 2005/0266315 A1 12, 2005 Sato et al. 2005. 2006.0024584 A1 2/2006 Kim et al. Machine translation of JP 2001-176511, Honbo et al., Jun. 2001. 2006.0035144 A1 2/2006 Shimizu et al. Submission of Publications for Application No. 2006-290637, dated 2006/O115730 A1 6/2006 Taniguchi et al. Mar. 14, 2011. Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 37 of 90 PageID: 37 U.S. Patent US 9,350,019 B2 Fig. A Fig. 1B O r Z UID - stress renar Serr Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 38 of 90 PageID: 38 U.S. Patent May 24, 2016 Sheet 2 of 2 US 9,350,019 B2 Fig. 2 Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 39 of 90 PageID: 39 US 9,350,019 B2 1. 2 NONAQUEOUS SECONDARY BATTERY AND thereof is usually 4.2 V or less. According to this charging METHOD OF USING THE SAME condition, the charge capacity is only about 60% of the theo retical capacity of LiCoO. The electric capacity may be CROSS-REFERENCE TO RELATED increased by increasing the charge final Voltage to higher than APPLICATIONS 5 4.2V. However, with the increase of the charge capacity, the crystalline structure of LiCoO decays so that the charge This application is a Divisional of application Ser. No. discharge cycle life may be shortened, or the crystalline struc 11/976,566 filed on Oct. 25, 2007, now U.S. Pat. No. 8,691, ture of LiCoO may be destabilized. Accordingly, the thermal 446, which claims priority under 35 U.S.C. I190a) to Patent stability of the battery deteriorates. Application No. 2006-290637 filed in Japan on Oct. 26, 2006. 10 To solve such a problem, many attempts have been made to All of the above applications are hereby expressly incorpo add a different metal element to LiCoO (cf. JP-A-4-171659, rated by reference into the present application. JP-A-3-201368, JP-A-7-176302 and JP-A-2001-167763). In addition, attempts have been made to use a battery in a FIELD OF THE INVENTION high-voltage range of 4.2V or higher (cf.JP-A-2004-29.6098, 15 JP-A-2001-176511 and JP-A-2002-270238). The present invention relates to a nonaqueous secondary In years to come, a secondary battery will be required to battery having a high capacity, good charge-discharge cycle have a higher capacity and also better reliability than the characteristics and high reliability Such as safety. conventional batteries. In general, the battery capacity can be greatly improved by raising the content of an active material RELATED ART 2O in electrodes or by increasing an electrode density, in particu lar, the density of a positive electrode mixture layer. However, In recent years, the secondary battery is an indispensable, according to such capacity-increasing measures, the reliabil important device as a power source of a personal computer or ity of the battery including storage characteristics gradually a cellular phone, or a power Source for an electric Vehicle oran decreases. electric power storage. 25 Accordingly, in order to meet requirements for the increase In particular, in applications for a mobile communication of the electric capacity, it is highly desired to provide a battery device Such as a portable computer and a personal digital which uses a material that generates a higher electromotive assistant, the battery is required to be made Smaller and to trim force (voltage range) than LiCoO and has a stable crystalline weight. Under the current circumstances, however, the sys structure capable of being stably and reversibly charged and tem of the battery is not easily made compact or lightweight, 30 discharged, and which further satisfies reliability such that the since an electric power consumed by a back light of a liquid safety of the conventional batteries can be maintained and the crystal display panel or consumed to control the drawing of battery does not expand during storage when the density of graphics is large, or the capacity of a secondary battery is not the positive electrode mixture layer is increased. Sufficiently large. In particular, a personal computer is pro When the discharge final voltage of a conventional battery gressively multi-functionalized by mounting a digital versa- 35 comprising LiCoO as a positive electrode active material is tile disc (DVD) drive and so on. Thus, the power consumption made higher than 3.2 V, the battery cannot be completely thereoftends to increase. For this reason, it is highly required discharged since the Voltage in the final stage of the discharge to increase the electric capacity of a secondary battery, in significantly falls. Thus, an electric quantity efficiency of particular, the discharge capacity, when the Voltage of a single discharge relative to charging remarkably decreases. Since battery is 3.3 V or higher. 40 the complete discharge cannot be attained, the crystalline Attention is paid to electric vehicles, which discharge no structure of LiCoO easily decays, and thus the charge-dis exhaust gas and make less noise in association with the charge cycle life is shortened. This phenomenon remarkably increase of global environmental problems. Recently, parallel appears in the above-mentioned high Voltage range. hybrid electric vehicles (HEV), which adopt a system of Under a charging condition that the final Voltage at full storing regenerative energy generated at the time of braking in 45 charging is set to 4.2V or higher in the conventional battery, a battery and making effective use of the energy, or using an apart from shortening of the charge-discharge cycle life or the electric energy stored in a battery at the time of engine starting decrease of the thermal stability caused by the decay of the to increase the efficiency of the engine system, have gained crystalline structure of the positive electrode active material, popularity. However, since the electric capacity of the cur the electrolytic solution (a solvent) is oxidatively decom rently used battery is small, a plurality of batteries should be 50 posed due to the increase of the active sites in the positive used to generate a Sufficient Voltage. For this reason, prob electrode active material, whereby a passivation film is lems such that a space in the vehicle should be made smaller formed on the surface of the positive electrode and thus the and that the stability of the vehicle body deteriorates arise. internal resistance of the battery increases so that the load Among secondary batteries, a lithium secondary battery characteristic may deteriorate. using a nonaqueous electrolyte attracts attention, since it gen- 55 erates a high Voltage, has a lightweight and is expected to SUMMARY OF THE INVENTION achieve a high energy density. In particular, a lithium second ary battery disclosed in JP-A-55-136131, in which a lithium An object of the present invention is to provide a nonaque containing transition metal oxide, for example, LiCoO, is ous secondary battery having a high capacity, good charge used as a positive electrode active material, and metal lithium 60 discharge cycle characteristics and high storage characteris is used as a negative electrode active material, is expected to tics. attain a high energy density, since it has an electromotive Accordingly, the present invention provides a nonaqueous force of 4V or higher. secondary battery comprising: a positive electrode having a However, at present, in the case of a LiCoO based second positive electrode mixture layer, a negative electrode, and a ary battery which uses LiCoO as a positive electrode active 65 nonaqueous electrolyte, wherein the positive electrode con material and a carbonaceous material Such as graphite as a tains, as an active material, at least one lithium-containing negative electrode active material, a charge final Voltage transition metal oxide comprising at least one metal element Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 40 of 90 PageID: 40 US 9,350,019 B2 3 4 selected from the group consisting of Mg, Ti, Zr, Ge, Nb, Al characteristics or handling easiness. A polymer electrolyte or and Sn, the positive electrode mixture layer has a density of at a gel electrolyte may be used without any problem. least 3.5 g/cm, and the nonaqueous electrolyte contains a The solvent in the nonaqueous electrolytic Solution is not compound having at least two nitrile groups in the molecule. particularly limited, and examples thereof include acyclic The nonaqueous secondary battery of the present invention 5 esters such as dimethyl carbonate, diethyl carbonate, ethyl can be charged at a high Voltage and thus has a large capacity, methyl carbonate, and methyl propyl carbonate; cyclic esters since the positive electrode mixture layer has a density of a having a high dielectric constant, such as ethylene carbonate, specific value or larger so as to increase the filled amount of propylene carbonate, butylene carbonate, and vinylene car the positive electrode active material in the positive electrode bonate; and mixed solvents comprising an acyclic ester and a 10 cyclic ester. Mixed solvents each comprising an acyclic ester mixture layer, and a lithium-containing transition metal oxide as a main solvent and a cyclic ester are particularly Suitable. comprising a specific metal element, which is highly stable in Apart form the esters exemplified above, the following a charged state at a high Voltage, is used as a positive electrode Solvents may also be used: acyclic phosphoric acid triesters active material. Such as trimethyl phosphate; ethers such as 1,2-dimethoxy Furthermore, since the positive electrode active material 15 ethane, 1,3-dioxolane, tetrahydrofuran, 2-methyl-tetrahydro used in the nonaqueous secondary battery of the present furan and diethyl ether, nitriles and dinitriles; isocyanates; invention has good stability, the decay of the active material is and halogen-containing solvents. Furthermore, amine or Suppressed when the charging and discharging of the battery imide organic solvents may be used. are repeated. Thereby, the nonaqueous secondary battery has Examples of the electrolyte salt to be dissolved in the good charge-discharge cycle characteristics. Solvent during the preparation of the nonaqueous electrolytic In addition, the nonaqueous electrolyte used in the non solution include LiClO LiPF LiBF LiAsF LiSbF. aqueous secondary battery of the present invention contains a LiCFSO, LiCFSO, LiCFCO, LiCF (SO), LiN compound having at least two nitrile groups in the molecule. (RfSO)(Rf'SO), LiC(RfSO). LiCFSO, wherein n>2. Such a nitrile compound acts on the surface of the positive and LiN(RfCSO), wherein Rf and Rf each represent a fluo electrode and functions to prevent the direct contact of the 25 roalkyl group. They may be used alone or in combination of positive electrode and the nonaqueous electrolyte. Thus, the two or more thereof. Among these electrolyte salts, particu reaction of the positive electrode and the nonaqueous elec larly preferred are fluorine-containing organic lithium salts trolyte is suppressed, whereby the generation of a gas in the having 2 or more carbon atoms, since such lithium salts have battery by Such a reaction is prevented. Accordingly, the a large anionic property and further ion separation easily suppression of the reaction of the positive electrode and the 30 occurs so that the salts are easily dissolved in the above nonaqueous electrolyte and the use of the positive electrode mentioned solvents. The concentration of the electrolyte salt active material having high stability synergistically function in the nonaqueous electrolytic solution is not particularly to prevent the expansion of the battery during the storage of limited, and it is preferably 0.3 mol/L or more, more prefer the charged battery at a high temperature and thus to improve ably 0.4 mol/L or more, while it is preferably 1.7 mol/L or the storage characteristics of the battery. 35 less, more preferably 1.5 mol/L or less. Consequently, the nonaqueous secondary battery of the According to the present invention, the nonaqueous elec present invention has good charge-discharge cycle character trolyte should contain a compound having at least two nitrile istics and good storage characteristics. The nonaqueous sec groups in the molecule. ondary battery of the present invention can be charged at a The nitrile compound used according to the present inven high positive electrode Voltage in a range of 4.35 to 4.6V with 40 tion can form a protective film on the surface of the positive reference to the potential of lithium, and thus it can be used in electrode active material during charging, in particular, initial applications which require a high output. charging, of the battery, and the protective film Suppresses the direct contact of the positive electrode and the nonaqueous BRIEF DESCRIPTION OF THE DRAWINGS electrolyte. Therefore, the battery of the present invention 45 comprising the nonaqueous electrolyte containing the com FIGS. 1A and 1B schematically show one example of the pound having at least two nitrile groups in the molecule can nonaqueous secondary battery of the present invention. FIG. prevent the generation of a gas in the battery due to the 1A is a plan view thereof and FIG. 1B is a partial vertical reaction of the positive electrode and the nonaqueous elec section thereof. trolyte, when it is stored at a high temperature of, for example, FIG. 2 shows a perspective view of the nonaqueous sec 50 about 85°C., in a charged state, since the protective film ondary battery illustrated in FIGS. 1A and 1B. formed of the nitrile compound prevents the positive elec trode and the nonaqueous electrolyte from direct contact and DETAILED DESCRIPTION OF THE INVENTION in turn prevents the reaction therebetween. The gas generated by the reaction of the positive electrode and the nonaqueous The nonaqueous secondary battery of the present invention 55 electrolyte in the battery causes the expansion of the battery may have Such a configuration that a laminate electrode body resulting in the decrease of the battery characteristics due to having a positive electrode with a positive electrode mixture the increase of the distance between the positive and negative layer and a negative electrode which are laminated each other electrodes. However, the battery of the present invention can withinserting a separator between them, or a wound electrode Suppress the expansion of the battery caused by the gas during body in which the laminate electrode body is wound is 60 storage and thus has good storage characteristics. enclosed within a housing together with a nonaqueous elec The compound having at least two nitrile groups in the trolyte. molecule may be one having two nitrile groups in the mol In the nonaqueous secondary battery of the present inven ecule, one having three nitrile groups in the molecule, etc. tion, the nonaqueous electrolyte is preferably a nonaqueous Among them, a dinitrile compound, that is, a compound Solvent-base electrolytic solution comprising an electrolyte 65 having two nitrile groups in the molecule is preferable since it salt Such as a lithium salt dissolved in a nonaqueous solvent has a better property to form the protective film and thus to Such as an organic solvent, from the viewpoint of electric prevent the reaction of the positive electrode and the nonaque Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 41 of 90 PageID: 41 US 9,350,019 B2 5 6 ous electrolyte. The dinitrile compound is preferably a com When two or more aromatic compounds are used together, the pound of the formula: NC R—CN wherein R is a linear or total amount thereof is within the above-mentioned range. branched hydrocarbon group having 1 to 10 carbon atoms, When the alkaryl (alkylaryl) compound and the aromatic preferably a linear or branched alkylene group having 1 to 10 compound which can be oxidized at a lower Voltage that the carbon atoms. alkaryl compound are used in combination, the content of the Specific examples of the dinitrile compound include mal alkaryl compound in the nonaqueous electrolytic Solution is ononitrile, Succinonitrile, glutaronitrile, adiponitrile, 1,4-di preferably 0.5% by weight or more, more preferably 2% by cyanoheptane, 1,5-dicyanopentane, 1,6-dicyanohexane, 1.7- weight or more, while it is preferably 8% by weight or less, dicyanoheptane, 2,6-dicyanoheptane, 1,8-dicyanooctane, more preferably 5% by weight or less. The content of the 2,7-dicyanooctane, 1,9-dicyanononane, 2,8-dicyanononane, 10 aromatic compound that can be oxidized at a lower Voltage 1,10-dicyanodecane, 1,6-dicyanodecane, 2,4-dimethylglu than the alkaryl compound in the nonaqueous electrolytic taronitrile, etc. solution is preferably 0.1% by weight or more, more prefer The nonaqueous electrolyte containing the nitrile com ably 0.2% by weight or more, while it is preferably 1% by pound may be prepared by any method. For example, the weight or less, more preferably 0.5% by weight or less. nitrile compound and the electrolyte salt are dissolved in the 15 Furthermore, a Surface protecting coating can beformed on solvent described above by a conventional method. the surface of the positive electrodeactive material in the step The amount of the nitrile compound is preferably at least of initial charging of the battery, when the nonaqueous elec 0.005% by weight, more preferably at least 0.01% by weight, trolytic Solution contains at least one compound selected still more preferably at least 0.05% by weight, based on the from the group consisting of halogen-containing organic Sol whole weight of the nonaqueous electrolyte, from the view vents (e.g., halogen-containing carbonates), organic Sulfur point of effectively utilizing the effects of the addition of the compounds, fluorine-containing organic lithium salts, phos nitrile compound. However, when the amount of the nitrile phorus-containing organic solvents, silicon-containing compound in the electrolyte is too large, the charge-discharge organic solvents, nitrogen-containing organic solvents other cycle characteristics of the battery tends to decrease although than the compounds having at least two nitrile groups in the the storage characteristics of the battery is improve. Thus, the 25 molecule, etc. In particular, the fluorine-containing organic amount of the nitrile compound is preferably 1% or less, more compounds such as fluorine-containing carbonate esters, the preferably 0.75% by weight or less, still more preferably organic Sulfur compounds and the fluorine-containing 0.5% by weight or less, based on the whole weight of the organic lithium salts are preferred. Specific examples thereof nonaqueous electrolyte. include F-DPC CFCHO(C=O)CCHCF), F-DEC Besides the nitrile compound, the nonaqueous electrolytic 30 ICF.CHO(C–O)OCHCF, HFE7100 (CFOCH), butyl solution may contain other additive or additives. A preferred sulfate (CHOSOOCH), methylethylene sulfate example of the additive is a nonionic aromatic compound. ( OCH(CH)CHO )SO), butyl Sulfate Specific examples thereof include aromatic compounds hav (CHSOCH), a polymer imide salt (I N(Li)SOOCH ing an alkyl group bonded to an aromatic ring (e.g., cyclo (CF)..CHOSO-1, wherein n is from 2 to 100), (CFSO) hexylbenzene, isopropylbenzene, tert-butylbenzene, tert 35 NLi, and (CF). CHOSO-NLi. amylbenzene, octylbenzene, toluene and Xylene); aromatic Such additives may be used alone. It is particularly prefer compounds having a halogen group bonded to an aromatic able to use a fluorine-containing organic solvent together with ring (e.g., fluorobenzene, difluorobenzene, trifluorobenzene a fluorine-containing organic lithium salt. The amount of and chlorobenzene); aromatic compounds having an alkoxy such an additive added is preferably 0.1% by weight or more, group bonded to an aromatic ring (e.g., anisole, fluoroanisole, 40 more preferably 2% by weight or more, particularly prefer dimethoxybenzene and diethoxybenzene); aromatic car ably 5% by weight or more, while it is preferably 30% by boxylic acid esters such as phthalic acid esters (e.g., dibutyl weight or less, more preferably 10% by weight or less, each phthalate and di-2-ethylhexyl phthalate) and benzoic acid based on the whole weight of the nonaqueous electrolytic esters; carbonic acid esters having a phenyl group (e.g., meth solution. When the amount of the additive is too large, the ylphenyl carbonate, butylphenyl carbonate and diphenyl car 45 electric characteristics of the battery may deteriorate. When bonate); phenyl propionate; and biphenyl. Among them, the the amount is too small, a good coating may hardly beformed. compounds having an alkyl group bonded to an aromatic ring When the battery comprising the nonaqueous electrolytic (alkaryl compounds) are preferred, and cyclohexylbenzene is Solution containing the above-mentioned additive(s) is particularly preferred. charged, particularly at a high Voltage, a Surface protecting The aromatic compounds exemplified above can also form 50 coating that contains fluorine or Sulfur atoms is formed on the a film on the surface of the active material in the positive positive electrode active material surface. This surface pro electrode or the negative electrode in the battery. These aro tecting coating may contain either fluorine atoms or Sulfur matic compounds may be used alone, while more advanta atoms. Preferably, the coating contains both of fluorine atoms geous effects can be attained by the use of two or more of the and Sulfur atoms. aromatic compounds together. Particularly advantageous 55 The amount of the Sulfur atoms in the Surface protecting effects can be attained on the improvement of the safety of the coating formed on the positive electrode active material Sur battery by the use of the alkaryl compound together with an face is preferably 0.5 atomic '% or more, more preferably 1 aromatic compound, which can be oxidized at a lower Voltage atomic '% or more, particularly preferably 3 atomic '% or than the alkaryl compound, Such as biphenyl. more. However, when the amount of the sulfur atoms in the The method for adding the aromatic compound in the non 60 positive electrode active material Surface is too large, the aqueous electrolytic Solution is not particularly limited. In discharge characteristic of the battery tends to decrease. Thus, general, the aromatic compound is added to the nonaqueous the amount is preferably 20 atomic 96 or less, more preferably electrolytic solution prior to the fabrication of the battery. 10 atomic '% or less, particularly preferably 6 atomic 96 or The content of the aromatic compound in the nonaqueous less. electrolytic solution is preferably 4% by weight or more from 65 The amount of the fluorine atoms in the Surface protecting the viewpoint of the safety, and it is preferably 10% by weight coating formed on the positive electrode active material Sur or less from the viewpoint of the load characteristic. face is preferably 15 atomic 96 or more, more preferably 20 Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 42 of 90 PageID: 42 US 9,350,019 B2 7 8 atomic '% or more, particularly preferably 25 atomic '% or more preferably 3.6 g/cm or more, particularly preferably more. However, when the amount of the fluorine atoms in the 3.8 g/cm or more. With such a density, the capacity of the positive electrode active material Surface is too large, the battery can be increased. However, when the density of the discharge characteristic of the battery tends to fall. Thus, the positive electrode mixture layer is too high, the wettability amount of the fluorine atoms is preferably 50 atomic '% or with the nonaqueous electrolyte, which will be explained less, more preferably 40 atomic '% or less, particularly pref later, decreases. Thus, the density is preferably 4.6 g/cm or erably 30 atomic 96 or less. less, more preferably 4.4 g/cm or less, particularly prefer In order to improve the charge-discharge cycle character ably 4.2 g/cm or less. istic of the battery, preferably, the nonaqueous electrolytic Herein, the density of the positive electrode mixture layer Solution contains at least one carbonate compound selected 10 may be obtained by the following measuring method: The from the group consisting of vinylene carbonates, such as positive electrode is cut to form a sample piece having a ( OCH=CHO )C=O, ( OCH=C(CH)O )C—O predetermined area, the sample piece is weighed with an and (—OC(CH)—C(CH)O )C—O, and derivatives electronic balance having a minimum scale of 1 mg, and then thereof cyclic carbonate esters having a vinyl group Such as the weight of the current collector is subtracted from the vinylethylene carbonate (—OCH CH(—CH=CH)O—) 15 weight of the sample piece to calculate the weight of the C=O); and fluorine-substituted ethylene carbonates, such as positive electrode mixture layer. The total thickness of the ( OCH CHFO )C=O and ( OCHF CHFO ) positive electrode is measured atten points with a micrometer C—O. The addition amount thereof is preferably 0.1% by having a minimum scale of 1 Lum. Then, the thickness of the weight or more, more preferably 0.5% by weight or more, current collector is subtracted from the resultant individual particularly preferably 2% by weight or more based on the thicknesses, and the thicknesses of the positive electrode whole weight of the nonaqueous electrolytic solution. When mixture layer measured at ten points are averaged. From the the addition amount thereof is too large, the load character averaged thicknesses of the positive electrode mixture layer istic of the battery tends to decrease. Thus, the addition and the surface area, the volume of the positive electrode amount is preferably 10% by weight or less, more preferably mixture layer is calculated. Finally, the weight of the positive 5% by weight or less, particularly preferably 3% by weight or 25 electrode mixture layer is divided by the volume thereof to less based on the whole weight of the nonaqueous electrolytic obtain the density of the positive electrode mixture layer. Solution. The positive electrode active material contained in the In the present invention, the nonaqueous electrolyte may be positive electrode mixture layer comprises a lithium-contain a gel-form polymer electrolyte besides the nonaqueous elec ing transition metal oxide comprising at least one metal ele trolytic solution described above. The gel-form polymer elec 30 ment selected from the group consisting of Mg, Ti, Zr, Ge. trolyte corresponds to a product obtained by the gelation of Nb, Al and Sn. The use of the lithium-containing transition the nonaqueous electrolytic solution with a gelling agent. For metal oxide can improve the charge-discharge cycle charac the gelation of the nonaqueous electrolytic solution, the fol teristics of the battery, since it has good stability, in particular, lowing gelling agents may be used: a linear polymer Such as in the charged State at a high Voltage, so that the decay of the polyvinylidene fluoride, polyethylene oxide or polyacryloni 35 compound is prevented when the charge-discharge cycle is trile, or a copolymer thereof, or a polyfunctional monomer repeated. Since the lithium-containing transition metal oxide which can be polymerized by irradiation with actinic rays has good stability, it can improve the storage characteristics Such as ultraviolet rays or electron beams (e.g., an acrylate and the reliability such as safety of the battery. having 4 or more functionalities such as pentaerythritol tet The positive electrode active material preferably has a par raacrylate, ditrimethylolpropane tetraacrylate, ethoxylated 40 ticle size frequency peak in a particle size range larger than a pentaerythritol tetraacrylate, dipentaerythritol hydroxypen midpoint d between do and do inaparticle size distribution taacrylate, or dipentaerythritol hexaacrylate; or a methacry curve, which obtained by a method for measuring an average late having 4 or more functionalities, which are analogous to particle size described below. To obtain a positive electrode the above acrylates. In the case of the monomer, the monomer active material having Such a particle size distribution, pref itself does not cause the gelling of the electrolytic solution, 45 erably, at least two lithium-containing transition metal oxides but the polymer formed from the monomer acts as a gelling having different average particle sizes are used. When a agent. lithium-containing transition metal oxide having a larger When a polyfunctional monomer is used to gel the electro average particle size and one having a smaller average par lytic Solution as described above, a polymerization initiator ticle size are used in combination, the particles of the latter may optionally be used. Examples of the polymerization 50 infill the gaps among the particles of the former. Thus, the initiator include benzoyls, benzoin alkyl ethers, benzophe positive electrode mixture layer having a large density as nones, benzoylphenylphosphine oxides, acetophenones, described above can be easily formed. thioxanthones and anthraquinones. As a sensitizer for the The “average particle size of the lithium-containing tran polymerization initiator, an alkylamine oran aminoester may sition metal oxide(s) used herein means a 50% diameter value be used. 55 (dso), that is, an median diameter, read from an integral frac In the present invention, the nonaqueous electrolyte may be tion curve based on Volumes, which is obtained by integrating a solid electrolyte besides the nonaqueous electrolytic solu the Volumes of the particles from a smaller particle size mea tion or the gel-form polymer electrolyte. The solid electrolyte sured by a MICROTRAC particle size analyzer (HRA9320 may be an inorganic Solid electrolyte or an organic Solid available from NIKKISO Co., Ltd.). Analogously, do and do electrolyte. 60 means a 10% diameter value and a 90% diameter value, The positive electrode according to the present invention respectively. may have a structure Such that the positive electrode mixture The mixture of “at least two lithium-containing transition layer containing the positive electrode active material is metal oxides having different average particle sizes' prefer formed on one or both of the surfaces of an electrode collec ably has a particle size frequency peak in a particle size range tOr. 65 larger than a midpoint d between do and doo in a particle The positive electrode mixture layer according to the size distribution curve, as described above. Hereinafter, a present invention may have a density of 3.5 g/cm or more, particle size corresponding to the particle size frequency peak Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 43 of 90 PageID: 43 US 9,350,019 B2 10 is expressed by “d.”. In a preferred embodiment, the ratio of containing transition metal oxides having an average particle d, to d. (d/d) is at least 1.05, more preferably at least 1.2, size between those of the positive electrode active materials most preferably at least 1.3. Furthermore, the ratio of d to d, (A) and (B). is preferably 1.6 or less, more preferably 1.5 or less, most The content of the positive electrode active material (B) preferably 1.45 or less. In a more preferred embodiment, the having the Smallest average particle size in the lithium-con lithium-containing transition metal oxide mixture has at least taining transition metal oxides contained in the positive elec two peaks in the particle size distribution curve. When the trode is preferably 5% by weight or more, more preferably lithium-containing transition metal oxides have the same 10% by weight or more, particularly preferably 20% by d/d of 1.3, the lithium-containing transition metal oxide weight or more. When the positive electrode active material mixture having at least two peaks in the particle size distri 10 (B) is contained in an amount of the above-mentioned range, bution curve can increase the density of the positive electrode the gaps between the particles of the lithium-containing tran mixture layer by 0.1 g/cm or more. When the particle size sition metal oxide having a relatively large particle size are distribution curve has two or more peaks, it can be divided easily filled therewith so that the density of the positive elec into a distribution curve corresponding to particles having a trode mixture layer is increased. When the content of the larger particle size and a distribution curve corresponding 15 positive electrode active material (B) is too large, the density particles having a smaller particle size by a common peak of the positive electrode mixture layer is hardly be increased. separation method and then an average particle size (do) of Thus, the content of the positive electrode active material (B) the respective lithium-containing transition metal oxide and a is preferably 60% by weight or less, more preferably 50% by mixing ratio of the lithium-containing transition metal oxides weight or less, particularly preferably 40% by weight or less. having the different average particle sizes can be calculated Accordingly, when the lithium-containing transition metal from the particle sizes and the cumulative volumes of the oxides contained in the positive electrode are only the positive particles. electrode active materials (A) and (B), the content of the When the average particle size of the lithium-containing positive electrode active material (A) is preferably 40% by transition metal oxide having the largest average particle size weight or more, more preferably 50% by weight or more, (hereinafter referred to as “positive electrode active material 25 particularly preferably 60% by weight or more of the oxides, (A)) is represented by A, and that of the lithium-containing while it is preferably 95% by weight or less, more preferably transition metal oxide having the Smallest average particle 90% by weight or less, particularly preferably 80% by weight size (hereinafter referred to as “positive electrode active or less. material (B)) is expressed by B, the ratio of B to A (i.e., B/A) Among the lithium-containing transition metal oxides con is preferably from 0.15 to 0.6. When the average particle sizes 30 tained in the positive electrode, the positive electrode active of the two positive electrode active materials (A) and (B) have material (B) having the Smallest average particle size has the such a ratio B/A, the density of the positive electrode mixture above-mentioned average particle size. Such a lithium-con layer can be easily increased. taining transition metal oxide having a relatively small par The positive electrode active material (A) preferably has an ticle size has low stability, for example, in a state that the average particle size of 5um or more, more preferably 8 um 35 battery is charged at a high Voltage, so that the oxide may or more, particularly preferably 11 Lum or more. When the damage the reliability including the safety of the battery. average particle size of the positive electrode active material When two or more lithium-containing transition metal (A) is too small, the density of the positive electrode mixture oxides having the different average particle sizes are used, a layer may hardly be increased. When the average particle size lithium-containing transition metal oxide comprising at least is too large, the battery characteristic tends to decrease. Thus, 40 one metal element M selected from the group consisting of the average particle size is preferably 25 um or less, more Mg, Ti, Zr, Ge, Nb, Al and Sn is preferably used at least as the preferably 20 um or less, particularly preferably 18 um or positive electrode active material (B) which is the lithium less. containing transition metal oxide having the Smallest average The positive electrode active material (B) preferably has an particle size, since the lithium-containing transition metal average particle size of 10 Lim or less, more preferably 7 um 45 oxide comprising the metal element M has the improved or less, particularly preferably 5um or less. When the average stability and thus Surely increases the charge-discharge cycle particle size of the positive electrode active material (B) is too characteristics of the battery and also improves the storage large, the positive electrode active material (B) does not easily characteristics and the reliability including the safety of the fill the gaps between the particles of the lithium-containing battery. transition metal oxide having a relatively large particle size in 50 When two or more lithium-containing transition metal the positive electrode mixture layer, so that the density of this oxides having the different average particle sizes are used, the layer may hardly be increased. When the average particle size positive electrode active material (B) having the smallest is too small, the Volume of Voids among the Small particles average particle size preferably comprises the metal element increases so that the density of the positive electrode mixture M. More preferably, the lithium-containing transition metal layer may not be increased. Thus, the average particle size of 55 oxide other than the positive electrode active material (B), for the positive electrode active material (B) is preferably 2 um or example, the positive electrode active material (A) having the more, more preferably 3 um or more, particularly preferably largest average particle size or the lithium-containing transi 4 um or more. tion metal oxide having the average particle size between The positive electrode active materials according to the those of the positive electrode active materials (A) and (B), present invention may contain only two lithium-containing 60 comprises the metal element M. When the lithium-contain transition metal oxides having different average particle ing transition metal oxide other than the positive electrode sizes, for example, the positive electrode active materials (A) active material (B) comprises the metal element M, the reli and (B) as descried above, while the positive electrode active ability including the safety of the battery can be further materials may contain three or more, for example, three, four improved, since Such a lithium-containing transition metal or five lithium-containing transition metal oxides having dif 65 oxide has the improved stability, in particular, the stability in ferent average particle sizes, for example, the positive elec a state that the battery is charged at a high Voltage as described trode active materials (A) and (B) and one or more lithium above. Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 44 of 90 PageID: 44 US 9,350,019 B2 11 12 The positive electrode active material (B) is preferably a preferably 0.99 or more, whilexanda are each preferably less lithium-containing transition metal oxide represented by the than 1.02, more preferably 1.01 or less, particularly prefer following formula (1): ably 1.00 or less. The values of y in the formula (1) and b in the formula (2) Li, M.M.M.O. (1) are each preferably 0.98 or more, more preferably 0.98 or wherein M' represents at least one transition metal element more, particularly preferably 0.99 or more, and they are each selected from Co, Niand Mn, M represents at least one metal preferably less than 1.02, more preferably less than 1.01, element selected from the group consisting of Mg, Ti, Zr, Ge. particularly preferably less than 1.0. Nb, Aland Sn, M represents an element other than Li, M' and Each of the positive electrode active material (B) repre M, and x, y, z and v are numbers satisfying the following 10 sented by the formula (1), and the lithium-containing transi equations respectively: 0.975x<1.02, 0.8sy<1.02, tion metal oxides other than the positive electrode active 0.002. US 9,350,019 B2 13 14 mole or more, particularly preferably 0.07% by mole or more inside the metal oxides, or may be unevenly present inside the based on the content of M', from the viewpoint of more metal oxides with having a density distribution. Furthermore, effectively attaining the effects of the use of these metal the element M” may form a compound which in turn forms a elements. layer on the particle surfaces. Preferably, the element M is Also, when the content of Mg is too large in the positive evenly present as a solid Solution. electrode active material (A), the load characteristic of the In the formulae (1) and (2) representing the positive elec battery tends to decrease. Therefore, the content of Mg is trode active material (B) and the other lithium-containing preferably less than 0.5% by mole, more preferably less than transition metal oxide(s), respectively, the element M is an 0.2% by mole, particularly preferably 0.1% by mole. element other than Li, M' and M. The positive electrode Also, when the content of Ti, Zr, Ge, Nb, Aland/or Sn is too 10 active material (B) and the other lithium-containing transition large in the positive electrode active material (A), the effect to metal oxides may each contain the M in an amount such that increase the capacity of the battery may not be sufficient. the advantageous effects of the present invention are not Thus, when the oxide contains Ti, Zr, Ge and/or Nb, the total impaired, or they may contain no M. content thereof is preferably less than 0.3% by mole, more Examples of the element M include alkali metals other preferably less than 0.1% by mole, particularly preferably 15 than Li (e.g., Na, K and Rb), alkaline earth metals other than less than 0.05% by mole based on the content of M'. When the Mg (e.g., Be, Ca,Sr and Ba), Group Ma metals (e.g., Sc., Y. oxide contains Al and/or Sn, the total amount thereof is pref La), Group IVa metals other than Ti and Zr (e.g., Hf), Group erably less than 0.5% by mole, more preferably less than Va metals other than Nb (e.g., V and Ta), Group VIa metals 0.2% by mole, particularly preferably less than 0.1% by mole (e.g., Cr, Mo and W), Group VIIb metals other than Mn (e.g., based on the content of M'. Tc and Re), Group VIII metals other than Co and Ni (e.g., Fe, Furthermore, when the lithium-containing transition metal Ru, and Rh), Group Ib metals (e.g., Cu, Ag and Au), Group oxide other than the positive electrode active materials (A) IIIb metals other than Zn and Al (e.g., B, Ca and In), Group and (B) is used, the content of Mg in the other metal oxide is IVb metals other than Sn and Pb (e.g., Si), P and Bi. preferably at least 0.01% by mole, more preferably at least The metal element M contributes to animprovement in the 0.05% by mole, particularly preferably at least 0.07% by 25 stability of the lithium-containing transition metal oxides. mole, based on the amount of the metal element M', from the However, when the content thereof is too large, a function of view point of more effectively attaining the effects of Mg. storing and releasing Li ions is impaired so that the battery When the lithium-containing transition metal oxide other characteristics may be decreased. Since the positive electrode than the positive electrode active materials (A) and (B) con active material (B) having the Smallest average particle size tains at least one metal element selected from Ti, Zr, Ge and 30 has the particularly Small particle size and decreased stability, Nb, the total content thereof is at least 0.005% by mole, more it is preferable that the content of the element M, which is a preferably at least 0.008% by mole, particularly preferably at stabilizing element, is somewhat high. In addition, since the least 0.01% by mole, based on the content of M', from the positive electrode active material (B) has the small particle viewpoint of more effectively attaining the effects of the use size and in turn the large Surface area, it exhibits a high of these metal elements. When the positive electrode active 35 activity. Thus, the presence of the element M in the material material (A) contains Al and/or Sn, the total content thereof is (B) has less influence on the function of storing and releasing preferably 0.01% by mole or more, more preferably 0.05% by Li ions. mole or more, particularly preferably 0.07% by mole or more In contrast, the lithium-containing transition metal oxides based on the content of M', from the viewpoint of more having relatively large particle sizes, that is, the lithium effectively attaining the effects of the use of these metal 40 containing transition metal oxides other than the positive elements. electrode active material (B), have better stability than the However, again in the lithium-containing transition metal positive electrode active material (B). Therefore, the former oxide other than the positive electrode active materials (A) metal oxides have less necessity to contain the element M and (B), when the content of Mg is too large, the load char than the positive electrode active material (B). Furthermore, acteristic of the battery tends to decrease. Therefore, the 45 their function of storing and releasing Li ions is easily content of Mg is preferably less than 2% by mole, more impaired by the presence of the element M since the mate preferably less than 1% by mole, particularly preferably 0.5% rials have the smaller surface area and the lower activity than by mole, most preferably 0.3% by mole, each based on the the positive electrode active material (B). content of M'. Accordingly, it is preferable that the content of the metal Again, in the lithium-containing transition metal oxide 50 element M' in the positive electrode active material (B) is other than the positive electrode active materials (A) and (B), larger than that in the lithium-containing transition metal when the content of Ti, Zr, Ge, Nb, Al and/or Sn is too large oxide(s) other than the positive electrode active material (B). in the positive electrode active material (A), the effect to That is, Zin the formula (1) is preferably larger than c in the increase the capacity of the battery may not be sufficient. formula (2) (ZDc). In particular, Z is at least 1.5 times, more Thus, when the oxide contains Ti, Zr, Ge and/or Nb, the total 55 preferably at least 2 times, particularly preferably at least 3 content thereof is preferably less than 0.5% by mole, more times larger than c. When Z is much larger than c, the load preferably less than 0.25% by mole, particularly preferably characteristics of the battery tend to decrease. Thus, Z is less than 0.15% by mole based on the content of M'. When the preferably less than 5 times as large as c', more preferably oxide contains Al and/or Sn, the total amount thereof is pref less than 4 times as large as c, particularly preferably less than erably less than 1% by mole, more preferably less than 0.5% 60 3.5 times as large as c. by mole, particularly preferably less than 0.3% by mole based When the three or more lithium-containing transition metal on the content of M'. oxides having the different average particle sizes are con A method for including the metal element M in the posi tained in the positive electrode, there is no especial limitation tive electrode active material (B) or the other lithium-contain on the relationship of the element M content between the ing transition metal oxide(s) is not particularly limited. For 65 positive electrode active material (A) having the largest aver example, the element M may be present on the particles of age particle size and the other lithium-containing transition the metal oxide, may be evenly present as a Solid Solution metal oxides. Thus, the former may contain a larger amount Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 46 of 90 PageID: 46 US 9,350,019 B2 15 16 of the element M than the latter, and vise versa, or the The contents of the metal elements in the positive electrode element M contents in the former and the latter may be the active materials are measured by the ICP atomic emission same. In a more preferable embodiment, a metal oxide having spectroscopy or the like. The content of lithium can be mea a smaller average particle size contains a larger amount of the Sured by an atomic absorption analysis. In the state of a element M. In particular, when the three lithium-containing positive electrode, it is difficult to separately measure the transition metal oxides having different average particle sizes contents of the metal elements in each of the positive elec are used, the element M content in the positive electrode trode active material having a larger particle size and one active material (B) having the Smallest average particle size is having a smaller particle size. Therefore, the contents or largest, that in lithium-containing transition metal oxide hav content ratios of the metal elements of the positive electrode 10 active material having different particle sizes may be mea ing the average particle size between those of the active Sured with an electron prove microanalyZerusing a mixture of materials (A) and (B) is second largest, and that in the positive positive electrode active materials having a known mixing electrode active material (A) having the largest average par ratio as a standard sample. Alternatively, the positive elec ticle size is Smallest. trode is treated with a suitable solvent such as N-methyl-2- When two or more lithium-containing transition metal 15 pyrrolidone (NMP) to separate the active material particles oxides are used, the oxides having different average particle from the positive electrode and settled out in the solvent, sizes may have the same composition of elements, or different followed by washing and drying. Then, the particle size dis compositions of elements between them. When the lithium tribution of the recovered particles is measured and the peak containing transition metal oxides according to the present separation of the particle size distribution curve is carried out. invention are the above-mentioned positive electrode active When the inclusion of two or more particles having different materials (A) and (B), the following combination may be particle sized is confirmed, the particles are classified into a used: a combination of the positive electrode active material larger one and a smaller one, and the contents of the metal (A) consisting of LiCoooosMgoooosTioooo-AloooosC2, and elements in each particle group are measured by the ICP the positive electrode active material (B) consisting of atomic emission spectroscopy. LiCoo.334Nio.33Mno.33 Mgoloo24Ti.o.ool2Alooo24O2. 25 Herein, the contents of the metal elements in the positive The positive electrodeactive material, namely, the lithium electrode active material may be measured by the ICP atomic containing transition metal oxide used according to the emission spectroscopy as follows: about 5 g of the active present invention is formed through a certain synthesizing material is precisely weighed and charged in a 200 ml beaker. process and a certain battery producing process. For example, Then, 100 ml of aqua regia is added, and the mixture is for the preparation of lithium-containing transition metal 30 concentrated by heating to a liquid volume of about 20 to 25 oxides which contain Co as the transition metal element M' ml. After cooling, the mixture is filtrated through a quantita and have different average particle sizes, firstly, a solution of tive filter paper (No. 5B available from Advantec MFS, Inc.) an alkali Such as NaOH is dropwise added to an acidic aque to separate the solids. The filtrate and washing liquid are ous Solution containing Co to precipitate Co(OH). In order to charged in a 100 ml measuring flask and diluted to a specific homogeneously precipitate Co(OH), Co may be coprecipi 35 Volume. Then, the contents of the metal elements in the solu tated with a different element, and then the coprecipitated tion are measured with a sequential type ICP analyzer (IPIS material is calcined to obtain Co-O. The particle size of the 1000 manufactured by Nippon Jarrel-Ash Co., Ltd.). precipitates can be adjusted by controlling the period for When the content (I) of at least one metal element selected forming the precipitates. The particle size of Co-O after from the group consisting of Mg, Ti, Zr, Ge, Nb, Al and Sn in calcination is also controlled by the particle size of the pre 40 the transition metal oxidehaving the Smallestaverage particle cipitate at this time. size and a content (II) of the same metal element as one with When the positive electrode active material is synthesized, which the content (I) in the lithium-containing transition conditions such as a mixing condition, calcination tempera metal oxide other than one having the Smallest average par ture, calcination atmosphere, calcination time, starting mate ticle size are measured by the ICP atomic emission spectros rials, and also battery fabrication conditions are Suitably 45 copy described above, the ratio of the content (I) to the con selected. With regard to the mixing condition in the synthesis tent (II) corresponds to the relationship between Z in the of the positive electrode active material, preferably, for formula (I) and c in the formula (2). The ratio of the content (I) example, ethanol or water is added to the powdery starting to the content (II) is preferably at least 1.5, more preferably at materials, and then mixed in a planetary ball mill for 0.5 hour least 2, particularly preferably at least 3. Since the load char or longer. More preferably, ethanol and water are mixed at a 50 acteristics of the battery tend to decrease when Z is much volume ratio of 50:50, and the mixture is agitated in a plan larger than c, the ratio of the content (I) to the content (II) is etary ball mill for 20 hours or longer. Through this mixing preferably less than 5, more preferably less than 4, particu step, the powdery starting materials are sufficiently commi larly preferably less than 3.5. nuted and mixed to prepare a homogeneous dispersion. The The positive electrode used in the present invention is dispersion is dried with a spray drier or the like while keeping 55 formed by, for example, a method described below. Firstly, if homogeneity. The calcination temperature is preferably from necessary, an electric conductive aid (e.g., graphite, carbon 750 to 1,050° C., more preferably from 950 to 1,030°C. The black, acetylene black, etc.) is added to the lithium-contain calcination atmosphere is preferably an air. The calcination ing transition metal oxide used as a positive electrode active time is preferably from 10 to 60 hours, more preferably from material. Furthermore, to the mixture, a binder (e.g., polyvi 20 to 40 hours. 60 nylidene fluoride, poly tetrafluoroethylene, etc.) is added to In the preparation of the positive electrode active material, prepare a positive electrode mixture. A solvent is used to LiCO is preferably used as a lithium source. As the sources formulate this positive electrode mixture in the form of a of other metal such as Mg, Ti, Ge, Zr, Nb, Aland Sn, preferred paste. The binder may be mixed with the positive electrode are nitrates or hydroxides of these metals, or oxides thereof active material and the like after the binder is dissolved in a having a particle size of 1 um or less. It is preferable to use the 65 Solvent. In this way, the paste containing the positive elec coprecipitate of the hydroxides since the different elements trode mixture is prepared. The resultant paste is applied to a are uniformly distributed in the active material. positive electrode current collector made of an aluminum foil Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 47 of 90 PageID: 47 US 9,350,019 B2 17 18 or the like, and then dried to form a positive electrode mixture material: alloys of Si, Sn, In or the like, oxides of Si, Snor the layer. If necessary, the layer is pressed to obtain a positive like that can be charged and discharged at a low Voltage near electrode. When the positive electrode active material com a voltage at which Li can be charged and discharged, and prises two ore more lithium-containing transition metal nitrides of Li and Co such as Li CoolN. Graphite can be oxides having the different average particle sizes, for partially substituted with a metal, a metal oxide or the like that example, the positive electrode active materials (A) and (B), can be alloyed with Li. When graphite is used as the negative they are mixed at a predetermined ratio, and then the electric electrode active material, the voltage when the battery is fully conductive aid and the binder are added to the mixture to charged can be regarded as about 0.1 V with reference to the prepare a positive electrode mixture, which is used in the potential of lithium, and therefore the voltage of the positive Subsequent steps. However, the method for producing the 10 electrode can be conveniently calculated as a Voltage obtained positive electrode is not limited to the above-mentioned by adding 0.1 V to the battery voltage. Consequently, the method, and may be any other method. charge Voltage of the positive electrode is easily controlled. The thickness of the positive electrode mixture layer is Preferably, graphite has such a form in that a lattice spacing preferably from 30 to 200 um, and the thickness of the current do of the (002) planes is 0.338 nm or less, since the negative collector used in the positive electrode is preferably from 8 to 15 electrode or a negative electrode mixture layer, which will be 20 um. explained later, has a higher density as the crystallinity is In the positive electrode mixture layer, the content of the higher. However, when the lattice spacing doo is too large, the lithium-containing transition metal oxides as the active mate high density negative electrode may decrease the discharge rials is preferably 96% by weight or more, more preferably characteristic or the load characteristic of the battery. Thus, 97% by weight or more, particularly preferably 97.5% by the lattice spacing doo is preferably 0.335 nm or more, more weight or more, while it is preferably 99% by weight or less, preferably 0.3355 nm or more. more preferably 98% by weight or less. The content of the The crystal size of the graphite in the c axis direction (Lc) binder in the positive electrode mixture layer is preferably 1% is preferably 70 nm or more, more preferably 80 nm or more, by weight or more, more preferably 1.3% by weight or more, particularly preferably 90 nm or more. As the Lc is larger, the particularly preferably 1.5% by weight or more, while it is 25 charging curve becomes flat so that the Voltage of the positive preferably 4% by weight or less, more preferably 3% by electrode is easily controlled and also the capacity can be weight or less, particularly preferably 2% by weight or less. made large. When the Lc is too large, the battery capacity The content of the electric conductive aid in the positive tends to decrease with the high-density negative electrode. electrode mixture layer is preferably 1% by weight or more, Thus, the Lc is preferably less than 200 nm. more preferably 1.1% by weight or more, particularly pref 30 Furthermore, the specific surface area of the graphite is erably 1.2% by weight or more, while it is preferably 3% by preferably 0.5 m/g or more, more preferably 1 m/g or more, weight or less, more preferably 2% by weight or less, particu particularly preferably 2 m/g or more, while it is preferably larly preferably 1.5% by weight or less. 6 m/g or less, more preferably 5 m/g or less. Unless the When the content of the active material in the positive specific Surface area of the graphite is somewhat large, the electrode mixture layer is too small, the capacity cannot be 35 characteristics tend to decrease. When the specific surface increased and also the density of the positive electrode mix area is too large, the graphite easily reacts with the electrolyte ture layer cannot be increased. When this content is too large, and Such a reaction may have influences on the properties of the resistance may increase or the formability of the positive the battery. electrode may be impaired. When the binder content in the The graphite used in the negative electrode is preferably positive electrode mixture layer is too large, the capacity may 40 made of natural graphite. More preferred is a mixture of two hardly be increased. When this content is too small, the adhe or more graphite materials having different Surface crystal sion of the layer to the current collector decreases so that the linity to achieve the high density of the negative electrode. powder may drop off from the electrode. Thus, the above Since natural graphite is inexpensive and achieves a high mentioned preferable ranges are desirable. Furthermore, capacity, the negative electrode with a high cost performance when the content of the electric conductive aid in the positive 45 can be produced. Usually, when natural graphite is used, the electrode mixture layer is too large, the density of the positive battery capacity is easily decreased as the density of the electrode mixture layer may not be made Sufficiently high so negative electrode is increased. However, the decrease in the that the capacity may hardly be increased. When this content battery capacity can be suppressed by mixing the natural is too small, the Sufficient electric conduction through the graphite with a graphitehaving a reduced Surface crystallinity positive electrode mixture layer is not attained so that the 50 by a Surface treatment. charge-discharge cycle characteristic or the load characteris The surface crystallinity of specific graphite can be deter tic of the battery may deteriorated. mined by the Raman spectrum analysis. When the R value of It is essential for the nonaqueous secondary battery of the the Raman spectrum (R-Iso/Isso, that is, the ratio of the present invention to have the nonaqueous electrolyte and the Raman intensity around 1350 cm to that around 1580 cm) positive electrode, which are explained above, and thus there 55 is 0.01 or more, where the Raman spectrum is measured with is no specific limitation on other elements or structure of the graphite which has been excited with an argon laser having a battery. The battery of the present invention may adopt vari wavelength of 514.5 nm, the surface crystallinity of the spe ous elements and structures, which are commonly adopted in cific graphite is slightly lower than that of natural graphite. the conventional nonaqueous secondary batteries in the State Thus, with the graphite having a Surface crystallinity of art. 60 decreased by the surface treatment, the R value is preferably The negative electrode active material in the negative elec 0.01 or more, more preferably 0.1 or more, while it is prefer trode may be any material that can be doped and de-doped ably 0.5 or less, more preferably 0.3 or less. The content of the with Li ions. Examples thereof are carbonaceous materials graphite having a surface crystallinity decreased by Surface Such as graphite, pyrolytic carbons, cokes, glassy carbons, treatment is preferably 100% by weight of the whole graphite burned bodies of organic polymers, mesocarbon microbeads, 65 in order to increase the density of the negative electrode. carbon fibers and activated carbon. In addition, the following However, in order to prevent the decrease of the battery materials can also be used as the negative electrode active capacity, the content of such graphite is preferably 50% by Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 48 of 90 PageID: 48 US 9,350,019 B2 19 20 weight or more, more preferably 70% by weight or more, ether compound Such as carboxymethylcellulose and the rub particularly preferably 85% by weight or more of the whole bery polymer Such as the styrene-butadiene copolymer rub graphite. ber are used in combination, the weight of the former to the When the average particle size of the graphite is too small, latter is preferably from 1:1 to 1:15. an irreversible capacity increases. Thus, the average particle 5 The thickness of the negative electrode mixture layer is size of the graphite is preferably 5 um or more, more prefer preferably from 40 to 200 um. The thickness of the current ably 12 um or more, particularly preferably 18 um or more. collector used in the negative electrode is preferably from 5 to From the viewpoint of the increase of the capacity of the 30 um. negative electrode, the average particle size of the graphite is In the negative electrode mixture layer, the content of the 30 um or less, more preferably 25 um or less, particularly 10 binder or binders is preferably 1.5% by weight or more, more preferably 20 um or less. preferably 1.8% by weight or more, particularly preferably The negative electrode may be produced by the following 2.0% by weight or more of the layer, while it is preferably less method, for example: The negative electrode active material than 5% by weight, less than 3% by weight, less than 2.5% by and an optional a binder and/or other additives are mixed to weight. When the amount of the binder in the negative elec prepare a negative electrode mixture, and the mixture is dis- 15 trode mixture layer is too large, the discharge capacity of the persed in a solvent to prepare a paste. Preferably, the binder is battery may decrease. When the amount is too small, the dissolved in a solvent prior to mixing with the negative elec adhesion between the particles decreases. The content of the trode active material, and then mixed with the negative elec negative electrode active material in the negative electrode trode active material and so on. The paste containing the mixture layer is preferably more than 95% by weight and negative electrode mixture is applied to a negative electrode 20 98.5% by weight or less. current collector made of a copper foil or the like, and then In the present invention, a separator used in the present dried to form a negative electrode mixture layer. The layer is invention preferably has a thickness of 5 um or more, more pressed to obtain a negative electrode. However, the method preferably 10 um or more, particularly preferably 12 um or for producing the negative electrode is not limited to the more, while it is preferably less than 25um, more preferably above-mentioned method, and may be any other method. 25 less than 20 Lum, particularly preferably less than 18 um, from The density of the negative electrode mixture layer after the viewpoint of imparting the directionality of the tensile pressing is preferably 1.70 g/cm or more, more preferably strength to the separator, keeping good insulating properties 1.75 g/cm or more. Based on the theoretical density of graph and reducing the thermal shrinkage of the separator. The gas ite, the upper limit of the density of the negative electrode permeability of the separator is preferably 500 second/100 mixture layer formed using graphite is 2.1 to 2.2 g/cm. The 30 mL or less, more preferably 300 second/100-mL or less, density of the negative electrode mixture layer is preferably particularly preferably 120 second/100-mL or less. As the gas 2.0 g/cm or less, more preferably 1.9 g/cm or less from the permeability of the separator is smaller, the load characteris viewpoint of the affinity with the nonaqueous electrolyte. It is tic is made better but an inside short-circuit is more easily preferable to press the negative electrode plural times since caused. Thus, the gas permeability is preferably 50 second/ the negative electrode can be uniformly pressed. 35 100-mL or more. Here, a gas permeability is measured The binder used in the negative electrode is not particularly according to JISP8117. As the thermal shrinkage factor of the limited. For the increase of the content of the active material separator in the transverse direction (TD) is Smaller, an inside to increase the capacity, the amount of the binder is preferably short-circuit is less easily caused when the temperature of the made as small as possible. To this end, the binder is preferably battery rises. Thus, the thermal shrinkage factor in TD of the a mixture of an aqueous resin which can be dissolved or 40 separatoris as Small as possible. The thermal shrinkage factor dispersed, and a rubbery polymer, since the use of only a in TD is preferably 10% or less, more preferably 5% or less. Small amount of the aqueous resin can contribute to the dis In order to restrain the thermal shrinkage of the separator, it is persion of the graphite and thus prevents the delamination of preferable to thermally treat the separator in advance at a the negative electrode mixture layer from the current collec temperature of about 100 to 125° C. The separator having tor caused by the expansion and contraction of the electrode 45 such a thermal shrinkage factor is preferably combined with in the charge-discharge cycles. the positive electrode materials according to the present Examples of the aqueous resins include cellulose resins invention to fabricate a battery, since the behaviors of the Such as carboxymethylcellulose, and hydroxypropylcellu battery at high temperature become stable. lose, and polyvinylpyrrolidone, polyepichlorohydrin, polyvi The thermal shrinkage factor in TD of the separator means nylpyridine, polyvinyl alcohol, polyether resins such as poly- 50 the shrinkage factor of a portion thereof that most largely ethylene oxide and polyethylene glycol, etc. Examples of the shrinks in TD when the separator having a size of 30 mm rubbery polymers include latex, butyl rubber, fluororubber, square is allowed to stand at 105° C. for 8 hours. styrene-butadiene rubber, nitrile-butadiene copolymer rub With regard to the strength of the separator, a tensile ber, ethylene-propylene-diene copolymer (EPDM), polyb strength in the machine direction (MD) is preferably 6.8x107 utadiene, etc. From the viewpoint of the dispersibility of the 55 N/m or more, more preferably 9.8x10 N/m or more. The graphite particles and the prevention of delamination of the tensile strength in TD is preferably smaller than that in MD. layer, it is preferable to use a cellulose ether compound Such The ratio of the tensile strength in TD to that in MD (tensile as carboxymethylcellulose together with abutadiene copoly strength in TD/tensile strength in MD) is preferably 0.95 or mer rubber such as a styrene-butadiene rubber. It is particu less, more preferably 0.9 or less, while it is preferably 0.1 or larly preferable to use carboxymethylcellulose together with 60 more. The transverse direction means a direction perpendicu a butadiene copolymer rubber Such as a styrene-butadiene lar to the direction in which the film resin for the production copolymer rubber or a nitrile-butadiene-copolymer rubber. of the separator is wound up, that is, the machine direction. The cellulose ether compound such as carboxymethylcellu The puncture strength of the separator is preferably 2.0 N lose mainly has a thickening effect on the paste containing the or more, more preferably 2.5 N or more. As this value is negative electrode mixture, while the rubbery polymer such 65 higher, the battery is less easily short-circuited. Usually, how as the styrene-butadiene copolymer rubber has a binding ever, the upper limit thereof is substantially determined by the effect on the negative electrode mixture. When the cellulose material of the separator. In the case of a separator made of Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 49 of 90 PageID: 49 US 9,350,019 B2 21 22 polyethylene, the upper limit of the puncture strength is about Voltage of 4.45 V or higher is assumed as a charging of the 10 N. Here, a puncture strength is measured by cutting a battery in which the voltage of the positive electrode is sub sample piece of 50 mmx50 mm from a separator, clamping stantially 4.35 V or higher. the sample piece with jigs at the edges of 5 mm, puncturing The nonaqueous secondary battery of the present invention the sample piece with a needle having a tip end with a radius has characteristics including a high Voltage, a high capacity of 0.5 mm at a rate of 2 mm/sec., and measuring a maximum and a high safety. By making use of such characteristics, the load before the puncture of the sample piece as a puncture nonaqueous secondary battery of the present invention can be strength. used as a power source of a notebook personal computer, a When a conventional nonaqueous secondary battery is stylus-operated personal computer, a pocket personal com charged at a high positive electrode voltage of 4.35 V or 10 higher with reference to the potential of lithium and is dis puter, a notebook word processor, a pocket word processor, an charged to a final Voltage higher than 3.2 V, the crystalline electronic book player, a cellular phone, a codeless handset, a structure of the positive electrode active material decays to pager, a portable terminal, a portable copier, an electrical decrease the capacity or to induce heating of the battery due to notebook, an electronic calculator, a liquid crystal television the deterioration of the thermal stability. Thus, the battery 15 set, an electric shaver, an electric power tool, an electronic may not be practically used. When a positive electrode active translating machine, an automobile telephone, a transceiver, a material to which a different element such as Mg or Ti is Voice input device, a memory card, a backup power source, a added is used, the decrease of the safety or of the capacity tape recorder, a radio, a headphone stereo, a handy printer, a over charge-discharge cycles can be suppressed, but the handy cleaner, a portable CD player, a MD player, a portable degree of Suppression is not sufficient. Moreover, the filling digital audio player, a video movie, a navigation system, a of the positive electrode is insufficient so that the battery refrigerator, an air conditioner, a television, a stereo, a water easily expands. heater, a microwave oven, a dishwasher, a washing machine, In contrast, the battery of the present invention having the a drying machine, a game equipment, a lighting equipment, a structure explained above is a nonaqueous secondary battery toy, a sensor equipment, a load conditioner, a medical which improves the capacity, the charge-discharge cycle 25 machine, an automobile, an electric vehicle, a golf cart, an characteristic, the safety and the Suppression of expansion of electrically-powered cart, a security system, a power storing the battery (storage characteristics). These advantageous system, or the like. The battery can be used not only for the effects can be attained at a usual charging volt (a battery consumer applications but also for aerospace applications. voltage of 4.2V). Furthermore, when the positive electrode is The capacity-increasing effect of the present invention is charged up to a high voltage of 4.35 V with reference to the 30 enhanced, in particular, in Small-sized portable devices. Thus, potential of lithium (i.e., a battery voltage of 4.25 V) and then the battery of the present invention is used in a portable device the discharge of the battery is terminated at a high voltage, desirably having a weight of 3 kg or less, more desirably 1 kg that is, a battery voltage of 3.2 V or higher, the crystalline or less. The lower limit of the weight of the portable device is structures of the positive electrode active materials are very not particularly limited. However, the lower limit is desirably stable so that the decrease of the capacity or thermal stability 35 a value equal to the weight of the battery, for example, 10g or is prevented. more in order to attain the advantageous effects to some Moreover, the positive electrode active material of any degree. conventional nonaqueous secondary battery generates a low average Voltage. Therefore, when a charge-discharge cycle EXAMPLES test is repeated under a condition that the discharge final 40 voltage of a unit cell is 4.35 V or higher with reference to the The present invention will be described in detail with ref potential of lithium, the positive electrode is doped or erence to the following Examples; however, the Examples do dedoped with a large amount of Li ions. This situation is not limit the scope of the present invention. Thus, modifica analogous to a case where the battery is subjected to a charge tions of the examples are encompassed by the scope of the discharge cycle test under an overcharge condition. Under 45 present invention as long as the modifications do not depart Such a severe condition, any conventional positive electrode from the subject matter of the present invention, which has active material cannot maintain its crystalline structure so as been described above or will be described hereinafter. to cause disadvantages Such that the thermal stability declines or the charge-discharge cycle life is shortened. To the con Example 1 trary, the use of the positive electrode active material accord 50 ing to the battery of the present invention can overcome Such Production of Positive Electrode disadvantages of the conventional positive electrode active material. Thus, the present invention provides a nonaqueous The lithium-containing positive electrode materials, secondary battery which can be reversibly charged and dis LiCoooosMgoooosTio ooo-AloooosC2 (average particle size: charged even at a high Voltage. Such as a Voltage of 4.35 to 4.6 55 12 um) as a positive electrode active material (A), and V with reference to the potential of lithium, when the battery LiCoooo, Mgooo-Tioloo. 2Alooo-O2 (average particle size: 5 is fully charged. um) as a positive electrodeactive material (B) at a weight ratio Here, the “fully charged’ means that a battery is charged by of 65:35 were mixed. Then, 97.3 parts by weight of the charging it at a constant current of 0.2C to a specific Voltage mixture and 1.5 parts by weight of a carbonaceous material as and then charging it at a constant Voltage at the specific 60 an electric conductive aid were charged in a Volumetric feeder Voltage until the total charging time of the constant current as a device for Supplying powder. An amount of a 10 wt.% charging and the constant Voltage charging reaches 8 hours. solution of polyvinylidene fluoride (PVDF) in N-methyl-2- When the battery of the present invention has a graphite pyrrolidone (NMP) to be supplied to the feeder was adjusted negative electrode (i.e. a negative electrode containing graph to control a solid content in the mixture constantly at 94% by ite as a negative electrode active material) which has a Voltage 65 weight during kneading. While the amount of the mixed of 0.1 V with reference to the lithium potential when the materials Supplied in a unit time was controlled to a prede battery is fully charged, the charging of the battery to a battery termined amount, the materials were Supplied in a biaxial Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 50 of 90 PageID: 50 US 9,350,019 B2 23 24 kneading extruder and then kneaded. In this way, a paste average particle size: 21 um, doo: 0.3363 nm, size of the containing the positive electrode mixture was prepared. crystallite in the c axis direction (Lc): 60 nm, R value of the Separately, the positive electrode active materials (A) and Raman spectrum: 0.11) were mixed. Then, 98 parts by weight (B) were dissolved in aqua regia and the ratio of the elements of the graphite mixture, 1 part by weight of carboxymethyl contained in the materials (A) and (B) was measured by the 5 cellulose and 1 part by weight of a styrene-butadiene rubber ICP atomic emission spectroscopy, the results of which con were mixed in the presence of water to prepare a paste con firmed that they had the above elementary compositions. taining negative electrode mixture. This paste was uniformly The resultant paste was charged in a planetary mixer, and applied to both surfaces of a negative electrode current col then a 10 wt.% solution of PVDF in NMP and NMP were lector made of a strip-form copper foil having a thickness of added to dilute the paste, thereby adjusting the viscosity of the 10 10 um, and then dried to form negative electrode mixture paste at a level sufficient for application. This diluted paste layers. The resultant sheet was pressed with a roller until the containing the positive electrode active material mixture was density of the negative electrode mixture layers became 1.75 passed through a 70-mesh net to remove large Substances. g/cm. The resultant sheet was then cut out in a predetermined Thereafter, the paste was uniformly applied to both surfaces size. Thereafter, a lead member made of nickel was welded to of a positive electrode current collector made of an aluminum 15 the cut piece to form a sheet-form negative electrode. foil with a thickness of 15um, and then dried to form film Preparation of Nonacqueous Electrolytic Solution form positive electrode mixture layers. In the dried positive An amount of LiPF was dissolved in a mixed solvent of electrode mixture layers, the weight ratio of the positive elec methylethyl carbonate, diethyl carbonate and ethylene car trode active material/the electric conduction aiding agent/ bonate mixed at a Volume ratio of 1:3:2 to attain a concentra PVDF was 97.3:1.5:1.2. Thereafter, the resultant sheet was tion of 1.4 mol/L. To this solution, 0.2% by weight of succi pressed and cut out in a predetermined size. To the cut piece, nonitrile and 3% by weight of vinylene carbonate were added a lead member made of aluminum was welded to form a to prepare a nonaqueous electrolytic Solution. sheet-form positive electrode. The density of the pressed Production of Nonacqueous Secondary Battery positive electrode mixture layers (the density of the positive The positive electrode and the negative electrode were electrode) was 3.86 g/cm. The thickness of the positive elec 25 spirally wound with interposing, therebetween, a separator trode mixture layers (the total thickness of the layers on both made of a microporous polyethylene film (porosity: 53%, the Surfaces, i.e., the thickness obtained by Subtracting the tensile strength in MD: 2.1x10 N/m, tensile strength in TD: thickness of the aluminum foil layer of the positive electrode 0.28x10 N/m, thickness: 16 Jum, gas permeability: 80 sec current collector from the total thickness of the positive elec onds/100-mL, thermal shrinkage factor after being kept at trode) was 135um. 30 105° C. for 8 hours: 3%, puncture strength: 3.5 N (360 g)), to The particle size distribution of the mixture of the positive form an electrode body having a spiral structure. Thereafter, electrode active materials (A) and (B) was measured by a the electrode body was pressed to form a flat-shaped electrode MICROTRAC particle size analyzer (HRA 9320 available body and inserted into a box-shaped battery case made of an from NIKKISO Co., Ltd.). In the particle size distribution aluminum alloy. The positive and negative lead members curve, two peaks were found at an average particle size of 35 were welded and a cover plate was laser welded to the edge about 5um and 12um, respectively. d, was larger thand, and portion of an opening of the battery case. Then, the nonaque d/dt was 1.4. ous electrolytic Solution prepared in the above was poured In the positive electrode active material (A), the amount of into the battery case through an inlet made in the cover plate. Mg was 0.08% by mole, that of Ti was 0.04% by mole, and The nonaqueous electrolytic solution was Sufficiently infil that of Al was 0.08% by mole, each based on the amount of 40 trated into the separator and the like. Thereafter, the battery Co. An electron prove X-ray microanalyzer (EMPA 1600 was partially charged, and gas generated during the partial manufactured by Shimadzu Corporation) was used to mea charging was discharged. Then, the inlet was sealed up to sure the concentration of the metal element M in cross sec make the battery airtight. Thereafter, the battery was charged tions of the particles. As a result, no difference in the concen and aged to yield a rectangular nonaqueous secondary battery tration of each of Mg, Ti and Al was observed between the 45 having a structure as shown in FIGS. 1A and 1B and an Surface portion and the core portion. external appearance as shown in FIG. 2, and a width of 34.0 In the positive electrode active material (B), the amount of mm, a thickness of 4.0 mm, and a height of 50.0 mm. Mg was 0.24% by mole, that of Ti was 0.12% by mole, and Here, the battery shown in FIGS. 1A, 1B and 2 will be that of Al was 0.24% by mole, each based on the amount of explained. The positive electrode 1 and the negative electrode Co. The concentration of the metal element M in the cross 50 2 are spirally wound with interposing the separator 3 therebe sections of the particles was measured in the same manner as tween, as described above, and the spirally wound electrode in the case of the positive electrode active material (A). As a body is pressed in a flatform to form the electrode laminate 6 result, no difference in the concentration of each of Mg, Ti having a flat spiral structure. The laminate 6 together with a and Al was observed between the surface portion and the core nonaqueous electrolytic solution is contained in the box portion. 55 shaped battery case 4. For simplicity, in FIG. 1, metal foils as With regard to the contents of the metal elements M, the current collectors used to form the positive electrode 1 and the molar contents of Mg, Ti and Al in the positive electrode negative electrode 2, and the electrolytic Solution are not active material (B) were 3 times larger, 3 times larger and 3 depicted. times larger, respectively, than those in the positive electrode The battery case 4 is made of an aluminum alloy, and active material (A). 60 constitutes a main part of the exterior package of the battery. Production of Negative Electrode This battery case 4 also functions as a positive electrode As negative electrode active materials, 70 parts by weight terminal. The insulator 5 made of a polytetrafluoroethylene of a graphite type carbonaceous material (a) (purity: 99.9% or sheet is arranged on the inside bottom of the battery case 4. more, average particle size: 18 um, doo: 0.3356 nm, size of The positive electrode lead member 7 and the negative elec the crystallite in the c axis direction (Lc): 100 nm, R value of 65 trode lead member 8 connected to one end of the positive the Raman spectrum: 0.18) and 30 parts by weight of a graph electrode 1 and that of the negative electrode 2, respectively, ite type carbonaceous material (b) (purity: 99.9% or more, are taken out from the electrode laminate 6 having the flat Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 51 of 90 PageID: 51 US 9,350,019 B2 25 26 spiral structure. The terminal 11 made of stainless steel is LiCoooossMgoooosTioooo-O2 (average particle size: 12 Lum), attached to the cover plate 9 made of aluminum for closing the and the positive electrode active material (B) was changed to opening of the battery case 4 with interposing the insulation LiCooooo, Mgoloo.24Ti.o.o.o.12O2 (average particle size: 5 (Lm). packing 10 made of polypropylene therebetween. The lead The density of the positive electrode mixture layers (positive plate 13 made of stainless steel is attached to this terminal 11 5 electrode) after pressing was 3.79 g/cm. With regard to the with interposing the insulator 12 therebetween. contents of the metal elements M, the molar contents of Mg The cover plate 9 is inserted into the opening of the battery and Ti in the positive electrode active material (B) were 3 case 4, and their joining portions are welded to each other, times larger and 3 times larger, respectively, than those in the thereby closing the opening of the battery case 4 to make the positive electrode active material (A). interior of the battery airtight. In the battery shown in FIGS. 10 2A and 2B, the inlet 14 for pouring Example 7 the electrolytic solution is made in the cover plate 9, and the inlet 14 is welded and sealed up by, for example, laser weld A nonaqueous secondary battery was fabricated in the ing, with inserting a sealing member (not shown). In this way, same manner as in Example 1 except that the weight ratio of the air-tightness of the battery is kept. Accordingly, in the case 15 the positive electrode active material (A) to the positive elec of the battery shown in FIGS. 2A, 2B and 3, the electrolytic trode active material (B) was changed to 90:10. The density of Solution pouring inlet 14 is actually composed of the inlet 14 the positive electrode mixture layers (positive electrode) after and the sealing member, but the inlet 14 is illustrated as such pressing was 3.75 g/cm. without a sealing member in order to make the figure simple. The explosion-proof vent 15 is made in the cover plate 9. Example 8 In the battery 1 of Example 1, the positive electrode lead member 7 is directly welded to the cover plate 9, whereby the A nonaqueous secondary battery was fabricated in the combination of the battery case 4 and the cover plate 9 func same manner as in Example 1 except that a mixture of the tions as a positive electrode terminal. The negative electrode positive electrode active material (A) consisting of lead member 9 is welded to the lead plate 13, and the negative 25 LiCoooosMgoooosTio-ooo-AloooosC2 (average particle size: electrode lead member 8 and the terminal 11 are made elec 12 um), and the positive electrode active material (B) consist trically conductive through the lead plate 13, whereby the ing of LiCooooo-Mgoloo.24Ti.o.o.o. 2Aloloo.4O2 (average par terminal 11 functions as a negative electrode terminal. How ticle size: 5 um) in a weight ratio of 50:50 was used as a ever, the functions of the positive and negative electrodes may positive electrode active material. The density of the positive be reversed in accordance with the material of the battery case 30 electrode mixture layers (positive electrode) after pressing 4, etc. was 3.76 g/cm. With regard to the contents of the metal FIG. 2 is a perspective view schematically illustrating the elements M, the molar contents of Mg, Ti and Al in the external appearance of the battery shown in FIGS. 1A and 1B. positive electrode active material (B) were 3 times larger, 3 FIG. 2 shows that the above-mentioned battery is a rectangu times larger and 3 times larger, respectively, than those in the lar battery. Thus, FIG. 2 schematically shows the battery, and 35 positive electrode active material (A). depicts the specific elements out of the constituting elements of the battery. Example 9 Example 2 A nonaqueous secondary battery was fabricated in the 40 same manner as in Example 1 except that the positive elec A nonaqueous secondary battery was fabricated in the trode active material (A) was changed to same manner as in Example 1 except that glutaronitrile was LiCoooosMgoooosTio-ooo-SnoooosC2 (average particle size: 14 lum), and the positive electrode active material (B) was used in place of Succinonitrile. changed to LiCoo. 994Mgoloo.24Ti.o.o.o.12Snooo.4O2 (average Example 3 45 particle size: 6 Lm). The density of the positive electrode mixture layers (positive electrode) after pressing was 3.76 A nonaqueous secondary battery was fabricated in the g/cm. With regard to the contents of the metal elements M, same manner as in Example 1 except that adiponitrile was the molar contents of Mg, Ti and Sn in the positive electrode used in place of Succinonitrile. active material (B) were 3 times larger, 3 times larger and 3 50 times larger, respectively, than those in the positive electrode Example 4 active material (A). A nonaqueous secondary battery was fabricated in the Example 10 same manner as in Example 1 except that the amount of succinonitrile was changed to 0.5% by weight. 55 A nonaqueous secondary battery was fabricated in the same manner as in Example 1 except that the positive elec Example 5 trode active material (A) was changed to LiCoooosMgoooos Zroooo-Alooooso2 (average particle size: A nonaqueous secondary battery was fabricated in the 13 lum), and the positive electrode active material (B) was same manner as in Example 1 except that the amount of 60 changed to LiCoooo.4Mgoloo.247mooo 12 Aloloo.24O2 (average Succinonitrile was changed to 1.0% by weight. particle size: 6 Lm). The density of the positive electrode mixture layers (positive electrode) after pressing was 3.8 Example 6 g/cm. With regard to the contents of the metal elements M, the molar contents of Mg, Zr and Al in the positive electrode A nonaqueous secondary battery was fabricated in the 65 active material (B) were 3 times larger, 3 times larger and 3 same manner as in Example 1 except that the positive elec times larger, respectively, than those in the positive electrode trode active material (A) was changed to active material (A). Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 52 of 90 PageID: 52 US 9,350,019 B2 27 28 Example 11 time reached 2.5 hours, followed by discharging at 1 CmA down to 3.0 V. Thereafter, the battery was again charged to 4.2 A nonaqueous secondary battery was fabricated in the Vata constant current of 1 C and then at a constant Voltage of same manner as in Example 1 except that the positive elec 4.2V until the total charge time reached 2.5 hours. Then, the trode active material (A) was changed to thickness T, of the battery (before storage) was measured. LiCoooosMgoooosGeoooo-AloooosC2 (average particle size: After the measurement of the thickness, the battery was 12 um), and the positive electrode active material (B) was stored in a thermostatic chamber kept at 85°C. for 24 hours, changed to LiCoooo-Mgoloo.24Geoloo.12 Aloloo.24O2 (average removed from the chamber and kept standing at room tem particle size: 6 Lm). The density of the positive electrode perature for 4 hours. Again, the thickness T of the battery mixture layers (positive electrode) after pressing was 3.79 10 (after storage) was measured. Using the thicknesses of the g/cm. With regard to the contents of the metal elements M, battery before and after storage, a rate of change of the battery the molar contents of Mg, Ge and Al in the positive electrode thickness was calculated according to the following equation: active material (B) were 3 times larger, 3 times larger and 3 times larger, respectively, than those in the positive electrode Rate of change (%)=(T-T)/Tx100 active material (A). 15 The results are shown in Table 1. Example 12 TABLE 1 A nonaqueous secondary battery was fabricated in the Discharge capacity same manner as in Example 1 except that the positive elec Example after Rate of change of trode active material (A) was changed to No. charge-discharge cycles batterythickness LiCOoss-Nioss MnossMgoloo.24Tioloo. 2Alooo24O2 (average 1 102 14.8 2 102 13.2 particle size: 5 Lm). The density of the positive electrode 3 103 11.6 mixture layers (positive electrode) after pressing was 3.72 4 101 12.6 g/cm. With regard to the contents of the metal elements M, 25 5 99 9.8 the molar contents of Mg, Ti and Al in the positive electrode 6 103 15.3 7 102 15.6 active material (B) were 3 times larger, 3 times larger and 3 8 103 15.2 times larger, respectively, than those in the positive electrode 9 102 15.3 active material (A). 10 103 15.4 30 11 103 15.6 Comparative Example 1 12 104 17.6 C. 1 100 2S.O A nonaqueous secondary battery was fabricated in the same manner as in Example 1 except that only As can be seen from the results in Table 1, the nonaqueous LiCoooosMgoooosTio ooo-AloooosC2 (average particle size: 35 secondary batteries of Examples 1-12 according to the 12 um) was used as a positive electrode active material and no present invention had the better discharge capacity, charge Succinonitrile was added to the nonaqueous electrolyte. The discharge cycle characteristics and storage characteristics density of the positive electrode mixture layers (positive elec than the nonaqueous secondary battery of Comparative trode) after pressing was 3.7 g/cm. This is a comparative Example 1. example using only a positive electrode active material hav 40 ing a large particle size, that is, the positive electrode active The invention claimed is: material (A), among the positive electrode active materials 1. A nonaqueous secondary battery comprising: a positive used in Example 1 and further no compound having at least electrode having a positive electrode mixture layer, a negative two nitrile compound was used. electrode, and a nonaqueous electrolyte, wherein With the nonaqueous secondary batteries fabricated in 45 the positive electrode contains, as an active material, at Examples 1-12 and Comparative Example 1, the following least two lithium-containing transition metal oxides properties were evaluated: having different average particle sizes, Discharge Capacity After Charge-Discharge Cycles said lithium-containing transition metal oxide having the Each of the batteries fabricated in Examples and Compara Smallest average particle size is a lithium-containing tive Example was discharged to 3.0 V at 1 CmA at a room 50 transition metal oxide represented by the formula (1): temperature, and charged to 4.2V at a constant current of 1 C and then at a constant Voltage of 4.2 V until the total charge Li, M.M.M.O. (1) time reached 2.5 hours. Thereafter, the battery was dis wherein M' represents at least one transition metal element charged at 0.2 CmA down to 3.0 V. Thereby, a discharge selected from Co, Ni and Mn, M represents Mg, or Mg capacity of the battery was measured. Then, the above charge 55 and at least one metal element selected from the group discharge cycle was repeated five times, and the discharge consisting of Ti, Zr, Ge, Nb, Aland Sn, M represents an capacity after the fifth cycle was used to evaluate the dis element other than Li, M' and M, and x, y, z and v are charge capacity after the charge-discharge cycles. The results numbers satisfying the equations respectively: are shown in Table 1. In Table 1, the discharge capacity after 0.97sx<1.02, 0.8sy<1.02, 0.002. US 9,350,019 B2 29 30 2. The nonaqueous secondary battery according to claim 1, wherein a lithium-containing transition metal oxide other than the lithium-containing transition metal oxide having the Smallest average particle size is a lithium-containing transi tion metal oxide represented by the formula (2): LiMMMO, (2) wherein M' represents at least one transition metal element selected from Co, Ni and Mn, M represents at least one metal element selected from the group consisting of Mg, 10 Ti, Zr, Ge, Nb, Aland Sn, M represents an element other than Li, M and M, and a, b, c and d are numbers satisfying the equations respectively: 0.97sa-1.02, 0.8sb-1,02, Oscs0.02, and 0 Exhibit 3 Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 55 of 90 PageID: 55 US009077035B2 (12) United States Patent (10) Patent No.: US 9,077,035 B2 Kita et al. (45) Date of Patent: Jul. 7, 2015 (54) NONAQUEOUS SECONDARY BATTERY AND (58) Field of Classification Search METHOD OF USING THE SAME CPC ...... H01 M 4/131; H01 M 4/52; H01 M 4/364; H01M 6/164: H01M 10/0525; H01M 10/0568; (75) Inventors: Fusaji Kita, Ibaraki (JP); Hideki H01M 2004/028; H01M 2300/0028: H01M Tsubata, Ibaraki (JP); Hiroyasu Inoue, 2300/0034; H01M 6/168; H01M 10/0569; Ibaraki (JP) H01M 10/0567; YO2E 60/122 USPC ...... 429/231.1, 231.3, 231.6, 231.5, 340, (73) Assignee: HITACHI MAXELL, LTD., Ibaraki-Shi 429/341, 50 (JP) See application file for complete search history. (*) Notice: Subject to any disclaimer, the term of this (56) References Cited patent is extended or adjusted under 35 U.S.C. 154(b) by 1224 days. U.S. PATENT DOCUMENTS 6,551,744 B1 * 4/2003. Ohzuku et al...... 429,223 (21) Appl. No.: 11/723,350 6,555,268 B1 * 4/2003 Inoue et al...... 429,217 (22) Filed: Mar 16, 2007 (Continued) (65) Prior Publication Data FOREIGN PATENT DOCUMENTS US 2007/0224.504 A1 Sep. 27, 2007 JP 8-2.27708 A 9, 1996 JP 10-112335 A 4f1998 (30) Foreign Application Priority Data (Continued) Mar. 20, 2006 (JP) ...... P2006-077O40 OTHER PUBLICATIONS Mar. 27, 2006 ... P2006-08498O Mar. 27, 2006 ... P2006-084981 English translation for Japanese Office Action, dated Mar. 27, 2012, Jan. 17, 2007 (JP) ...... P2007-007563 for Japanese Patent Application No. 2007-009861. Jan. 19, 2007 (JP) ...... P2007-009860 (Continued) Jan. 19, 2007 (JP) ...... P2007-009861 Primary Examiner — Laura Weiner (51) Int. Cl. (74) Attorney, Agent, or Firm — Birch, Stewart, Kolasch & HOLM 4/52 (2010.01) Birch, LLP HOLM 4/36 (2006.01) (Continued) (57) ABSTRACT (52) U.S. Cl. A nonaqueous secondary battery containing a positive elec CPC ...... H0IM 4/52 (2013.01); H0IM 4/364 trode having a positive electrode mixture layer, a negative (2013.01); H0IM 6/164 (2013.01); HOLM electrode, and a nonaqueous electrolyte, wherein the positive 6/168 (2013.01); HOIM 10/0525 (2013.01); electrode comprises, as active materials, two or more lithium HOIM 2004/028 (2013.01); HOIM 2300/0034 containing transition metal oxides having different average (2013.01); H0IM 10/0567 (2013.01); HOLM particle sizes, and the lithium-containing transition metal 4/02 (2013.01); H01 M 4/131 (2013.01); H0IM oxide having the Smallest average particle size contains one 4/485 (2013.01); or more of Mg, Ti, Zr, Ge, Nb, Al and Sn. (Continued) 11 Claims, 3 Drawing Sheets 15 12 O 10 Particle size (1 m) Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 56 of 90 PageID: 56 US 9,077,035 B2 Page 2 (51) Int. Cl. JP 2002-42890 A 2, 2002 HOLM 6/16 (2006.01) JP 2004-63269 A 23. JP 2004-182564. A 7, 2004 HIM I/0567 (2010.01) JP 2004-259675 A 9, 2004 HOLM 4/13 (2010.01) JP 2004-349132 A 12/2004 HOLM 4/485 (2010.01) JP 2005-5208 A 1, 2005 H0IM 10/0569 (2010.01) E. 636 A 3.58. HOIM IO/O525 (2010.01) HOIM 4/O2 (2006.01) JP 2005-302507 A 10/2005 (52) U.S. Cl. OTHER PUBLICATIONS CPC. H0IM 10/0569 (2013.01); HOIM 2004/021 (2013.01); Y02E 60/122 (2013.01) English translation for Japanese Office Action, dated Mar. 27, 2012, for Japanese Patent Application No. 2007-009860. (56) References Cited English translation for Japanese Office Action, dated May 15, 2012, for Japanese Patent Application No. 2007-007563. U.S. PATENT DOCUMENTS Office Action for corresponding Japanese Patent Application No. 2007-007563, issued on May 15, 2012. 6,737,195 B2 * 5/2004 Kweon et al...... 429,231.1 7,122.278 B1 * 10/2006 Nakashima et al. ... 429,224 Office Action for corresponding Japanese Patent Application No. 2006/01941 19 A1* 8, 2006 Son et al...... 429,330 2007-009860, issued on Mar. 27, 2012. Office Action for corresponding Japanese Patent Application No. FOREIGN PATENT DOCUMENTS 2007-009881, issued on Mar. 27, 2012. Korean Office Action and English translation thereof, dated Jul. 19. JP 11-54.122 A 2, 1999 2013, for Patent Application No. 10-2007-0026624. JP 11-868.45 A 3, 1999 JP 2000-82466 A 3, 2000 * cited by examiner Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 57 of 90 PageID: 57 U.S. Patent Jul. 7, 2015 Sheet 1 of 3 US 9,077,035 B2 Fig. 1 5 12 i Particle size (pum) Fig. 2A 1 O 9. 15 14 Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 58 of 90 PageID: 58 U.S. Patent US 9,077,035 B2 Fig. 2B -14 - ur-f ?-j======Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 59 of 90 PageID: 59 U.S. Patent Jul. 7, 2015 Sheet 3 of 3 US 9,077,035 B2 Fig. 3 Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 60 of 90 PageID: 60 US 9,077,035 B2 1. 2 NONAQUEOUS SECONDARY BATTERY AND To solve such a problem, many attempts have been made to METHOD OF USING THE SAME add a different metal element to LiCoO, (cf.JP-A-4-171659, JP-A-3-201368, JP-A-7-176302 and JP-A-2001-167763). FILED OF THE INVENTION In addition, attempts have been made to use a battery in a high-voltage range of 4.2V or higher (cf.JP-A-2004-29.6098, The present invention relates to a nonaqueous secondary JP-A-2001-176511 and JP-A-2002-270238). Also, attempts battery and a method of using the same. have been made to use a fluorine-containing organic Solvent or a Sulfur-containing organic solvent as a solvent of an elec RELATED ART trolyte (cf. JP-A-8-37024, JP-A-10-112334, JP-A-10 10 112335, JP-A-2000-123880, JP-A-6-302336 and JP-A-11 In recent years, the secondary battery is an indispensable, 162511). important device as a power source of a personal computer or In years to come, a secondary battery will be required to a cellular phone, or a power Source for an electric Vehicle oran have a higher capacity and also better reliability including electric power storage. higher safety than the conventional batteries. In general, the 15 battery capacity can be greatly improved by raising the con In particular, in applications for a mobile communication tent of an active material in electrodes or by increasing an device Such as a portable computer and a personal digital electrode density, in particular, the density of a positive elec assistant, the battery is required to be made Smaller and to trim trode mixture layer. However, according to such capacity weight. Under the current circumstances, however, the sys increasing measures, the safety of the battery gradually tem of the battery is not easily made compact or lightweight, decreases. since an electric power consumed by a back light of a liquid Accordingly, in order to meet requirements for the increase crystal display panel or consumed to control the drawing of of the electric capacity, it is highly desired to provide a battery graphics is large, or the capacity of a secondary battery is not which uses a material that generates a higher electromotive Sufficiently large. In particular, a personal computer is pro force (voltage range) than LiCoO and has a stable crystalline gressively multi-functionalized by mounting a digital versa 25 structure capable of being stably and reversibly charged and tile disc (DVD) drive and so on. Thus, the power consumption discharged, and which further satisfies reliability such that the thereoftends to increase. For this reason, it is highly required safety of the conventional batteries can be maintained and the to increase the electric capacity of a secondary battery, in battery does not expand when the density of the positive particular, the discharge capacity, when the Voltage of a single electrode mixture layer is increased. battery is 3.3 V or higher. 30 When the discharge final voltage of a conventional battery Attention is paid to electric vehicles, which discharge no comprising LiCoO as a positive electrode active material is exhaust gas and make less noise in association with the made higher than 3.2 V, the battery cannot be completely increase of global environmental problems. Recently, hybrid discharged since the Voltage in the final stage of the discharge electric vehicles (HEV), which adopt a system of storing significantly falls. Thus, an electric quantity efficiency of regenerative energy generated at the time of braking in a 35 discharge relative to charging remarkably decreases. Since the complete discharge cannot be attained, the crystalline battery and making effective use of the energy, or using an structure of LiCoO easily decays, and thus the charge-dis electric energy stored in a battery at the time of engine starting charge cycle life is shortened. This phenomenon remarkably to increase the efficiency of the engine system, have gained appears in the above-mentioned high Voltage range. popularity. However, since the electric capacity of the cur 40 Under a charging condition that the final Voltage at full rently used battery is small, a plurality of batteries should be charging is set to 4.2V or higher in the conventional battery, used to generate a Sufficient Voltage. For this reason, prob apart from shortening of the charge-discharge cycle life or the lems such that a space in the vehicle should be made smaller decrease of the thermal stability caused by the decay of the and that the stability of the vehicle body deteriorates arise. crystalline structure of the positive electrode active material, Among secondary batteries, a lithium secondary battery 45 the electrolytic solution (a solvent) is oxidatively decom using a nonaqueous electrolyte attracts attention, since it gen posed due to the increase of the active sites in the positive erates a high Voltage, has a lightweight and is expected to electrode active material, whereby a passivation film is achieve a high energy density. In particular, a lithium second formed on the surface of the positive electrode and thus the ary battery disclosed in JP-A-55-136131, in which a lithium internal resistance of the battery increases so that the load containing transition metal oxide, for example, LiCoO, is 50 characteristic may deteriorate. used as a positive electrode active material, and metal lithium is used as a negative electrode active material, is expected to SUMMARY OF THE INVENTION attain a high energy density, since it has an electromotive force of 4V or higher. An object of the present invention is to provide a nonaque However, at present, in the case of a LiCoO based second 55 ous secondary battery having a high capacity, good charge ary battery which uses LiCoO, as a positive electrode active discharge cycle characteristics, and high reliability including material and a carbonaceous material Such as graphite as a high safety, and a method of using the same. negative electrode active material, a charge final Voltage Accordingly, the present invention provides a nonaqueous thereof is usually 4.2 V or less. According to this charging secondary battery comprising: a positive electrode having a condition, the charge capacity is only about 60% of the theo 60 positive electrode mixture layer, a negative electrode, and a retical capacity of LiCoO. The electric capacity may be nonaqueous electrolyte, wherein the positive electrode com increased by increasing the charge final Voltage to higher than prises, as active materials, at least two lithium-containing 4.2V. However, with the increase of the charge capacity, the transition metal oxides having different average particle crystalline structure of LiCoO decays so that the charge sizes, and at least the lithium-containing transition metal discharge cycle life may be shortened, or the crystalline struc 65 oxide having the Smallest average particle size comprises at ture of LiCoO may be destabilized. Accordingly, the thermal least one metal element selected from the group consisting of stability of the battery deteriorates. Mg, Ti, Zr, Ge, Nb, Al and Sn. Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 61 of 90 PageID: 61 US 9,077,035 B2 3 4 Furthermore, the present invention provides a nonaqueous FIG. 3 shows a perspective view of the nonaqueous sec secondary battery comprising: a positive electrode having a ondary battery illustrated in FIGS. 2A and 2B. positive electrode mixture layer, a negative electrode, and a nonaqueous electrolyte, wherein the positive electrode com DETAILED DESCRIPTION OF THE INVENTION prises, as active materials, at least two lithium-containing transition metal oxides having different average particle The positive electrode used in the nonaqueous secondary sizes, the lithium-containing transition metal oxides com battery of the present invention comprises, as the active mate prise at least one metal element selected from the group rial, the mixture of at least two lithium-containing transition consisting of Mg, Ti, Zr, Ge, Nb, Al and Sn, and a ratio of a metal oxides having different average particle sizes. When the 10 lithium-containing transition metal oxide having a larger par content (I) of said at least one metal element selected from the ticle size and one having a smaller particle size are used in group consisting of Mg, Ti, Zr, Ge, Nb, Al and Sn in the combination, gaps between the particles of one having the transition metal oxide having the Smallest average particle larger particle size are filled with the particles of one having size to a content (II) of the same metal element as one with the Smaller particle size. Accordingly, the density of the posi which the content (I) is measured, in the lithium-containing 15 tive electrode mixture layer is increased and, in turn, the transition metal oxide other than one having the Smallest capacity of the battery is increased. average particle size is at least 1.5, where the contents (I) and The mixture of “at least two lithium-containing transition (II) are measured by an inductively coupled plasma (ICP) metal oxides having different average particle sizes has three atomic emission spectroscopy. or more inflection points in a particle size distribution curve The “average particle size' of the lithium-containing tran of the mixture. The particle size distribution curve may have sition metal oxides used herein means a 50% diameter value two or more peaks or a shoulder in one or more peaks. In the (dso), that is, an median diameter, read from an integral frac case of Such a particle size distribution curve, firstly, a con tion curve based on Volumes, which is obtained by integrating ventional peak-separating method is applied to separate a the Volumes of the particles from a smaller particle size mea distribution of particles having a larger particle size and that sured by a MICROTRAC particle size analyzer (HRA9320 25 of particles having a smaller particle size. Subsequently, from available from NIKKISO Co., Ltd.). the particle sizes and the integrated Volume, the average par The present invention also provides a method of using a ticle size (do) of each of the lithium-containing transition nonaqueous secondary battery according to the present inven metal oxides and the mixing ratio between them can be cal tion comprising the step of charging the battery so that a culated. positive electrode voltage is in a range of 4.35 to 4.6 V with 30 When the average particle size of the lithium-containing reference to the potential of lithium when the battery is fully transition metal oxide having the largest average particle size charged. (hereinafter referred to as "positive electrode active material For example, in the method of using the nonaqueous sec (A)') is represented by A, and that of the lithium-containing ondary battery according to the present invention, when the transition metal oxide having the Smallest average particle nonaqueous secondary battery of the present invention com 35 size (hereinafter referred to as “positive electrode active prises a graphite negative electrode, namely, a negative elec material (B)) is expressed by B, the ratio of B to A (i.e., B/A) trode containing graphite as a negative electrode active mate is preferably from 0.15 to 0.6. When the average particle sizes rial, which has a voltage of 0.1 V with reference to the lithium of the two positive electrode active materials (A) and (B) have potential when the battery is fully charged, charging the bat such a ratio B/A, the density of the positive electrode mixture tery up to a battery Voltage of 4.45 V or higher is regarded as 40 layer can be easily increased. charging the battery So as to Substantially attain a positive The positive electrode active material (A) preferably has an electrode voltage of 4.35 V or higher. average particle size of 5um or more, more preferably 8 um In the method of using the nonaqueous secondary battery or more, particularly preferably 11 Lum or more. When the according to the present invention, the term “fully charging average particle size of the positive electrode active material (charged) means charging under the following conditions: 45 (A) is too small, the density of the positive electrode mixture the battery is charged at a constant current of 0.2C up to a layer may hardly be increased. When the average particle size predetermined Voltage and Subsequently the battery is is too large, the battery characteristic tends to decrease. Thus, charged at a predetermined constant Voltage, provided that the average particle size is preferably 25 um or less, more the total time of the constant current charging and the constant preferably 20 Lum or less, particularly preferably 18 um or Voltage charging is set to 8 hours. 50 less. Consequently, the nonaqueous secondary battery of the The positive electrodeactive material (B) preferably has an present invention has a high capacity, good charge-discharge average particle size of 10 Lim or less, more preferably 7 um cycle characteristics and high reliability including high or less, particularly preferably 5um or less. When the average safety. particle size of the positive electrode active material (B) is too According to the using method of the present invention, the 55 large, the positive electrode active material (B) does not easily nonaqueous secondary battery of the present invention can be fill the gaps between the particles of the lithium-containing used in applications which require larger power output. transition metal oxide having a relatively large particle size in the positive electrode mixture layer, so that the density of this BRIEF DESCRIPTION OF THE DRAWINGS layer may hardly be increased. When the average particle size 60 is too small, the Volume of Voids among the Small particles FIG. 1 shows an example of a particle size distribution increases so that the density of the positive electrode mixture curve of a positive electrode active material used in the non layer may not be increased. Thus, the average particle size of aqueous secondary battery according to the present invention. the positive electrode active material (B) is preferably 2 um or FIGS. 2A and 2B schematically show one example of the more, more preferably 3 um or more, particularly preferably nonaqueous secondary battery of the present invention. FIG. 65 4 um or more. 2A is a plan view thereof and FIG. 2B is a partial vertical The positive electrode active materials according to the section thereof. present invention may contain only two lithium-containing Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 62 of 90 PageID: 62 US 9,077,035 B2 5 6 transition metal oxides having different average particle than the positive electrode active material (B) comprises the sizes, for example, the positive electrode active materials (A) metal element M, the reliability including the safety of the and (B) as descried above, while the positive electrode active battery can be further improved, since Sucha lithium-contain materials may contain three or more, for example, three, four ing transition metal oxide has the improved stability, in par or five lithium-containing transition metal oxides having dif 5 ticular, the stability in a state that the battery is charged at a ferent average particle sizes, for example, the positive elec high Voltage as described above. trode active materials (A) and (B) and one or more lithium The positive electrode active material (B) is preferably a containing transition metal oxides having an average particle lithium-containing transition metal oxide represented by the size between those of the positive electrode active materials following formula (1): (A) and (B). 10 The content of the positive electrode active material (B) Li, M.M.M.O. (1) having the Smallest average particle size in the lithium-con wherein M' represents at least one transition metal element taining transition metal oxides contained in the positive elec selected from Co, Niand Mn, M represents at least one metal trode is preferably 5% by weight or more, more preferably element selected from the group consisting of Mg, Ti, Zr, Ge. 10% by weight or more, particularly preferably 20% by 15 Nb, Aland Sn, Mrepresents an elementother than Li, M'and weight or more. When the positive electrode active material M, and x, y, Z and V are numbers satisfying the following (B) is contained in an amount of the above-mentioned range, Equations respectively: 0.975x<1.02, 0.8sy<1.02, the gaps between the particles of the lithium-containing tran 0.002 US 9,077,035 B2 7 8 element M' is preferably 30% by mole or more, more pref mole, based on the amount of the metal element M', from the erably 65% by mole or more, particularly preferably 95% by viewpoint of more effectively attaining the effects of Mg. mole or more. When the positive electrode active material (A) contains at The values of x in the formula (1) and a in the formula (2) least one metal element selected from Ti, Zr, Ge and Nb, the may vary as the battery is charged or discharged. Neverthe total content thereof is at least 0.005% by mole, more prefer less, when the battery is an as-produced one, X and a are each ably at least 0.008% by mole, particularly preferably at least preferably 0.97, more preferably 0.98 or more, particularly 0.01% by mole, based on the content of M', from the view preferably 0.99 or more, whilexanda are each preferably less point of more effectively attaining the effects of the use of than 1.02, more preferably 1.01 or less, particularly prefer these metal elements. When the positive electrode active 10 material (A) contains Al and/or Sn, the total content thereof is ably 1.00 or less. preferably 0.01% by mole or more, more preferably 0.05% by The values of y in the formula (1) and b in the formula (2) mole or more, particularly preferably 0.07% by mole or more are each preferably 0.98 or more, more preferably 0.98 or based on the content of M', from the viewpoint of more more, particularly preferably 0.99 or more, and they are each effectively attaining the effects of the use of these metal preferably less than 1.02, more preferably less than 1.01, 15 elements. particularly preferably less than 1.0. Also, when the content of Mg is too large in the positive Each of the positive electrode active material (B) repre electrode active material (A), the load characteristic of the sented by the formula (1), and the lithium-containing transi battery tends to decrease. Therefore, the content of Mg is tion metal oxides other than the positive electrode active preferably less than 0.5% by mole, more preferably less than material (B) which are represented by the formula (2) pref 0.2% by mole, particularly preferably 0.1 by mole. erably contains Mg as the element M, since the safety of the Also, when the content of Ti, Zr, Ge, Nb, Aland/or Sn is too battery is more effectively improved. In addition, each of large in the positive electrode active material (A), the effect to them comprises Mg and also at least one metal element M increase the capacity of the battery may not be sufficient. selected from the group consisting of Ti, Zr, Ge, Nb, Al and Thus, when the oxide contains Ti, Zr, Ge and/or Nb, the total Sn. In this case, the stability of those lithium-containing tran 25 content thereof is preferably less than 0.3% by mole, more sition metal oxides is further improved in a state that the preferably less than 0.1% by mole, particularly preferably battery is charged at a high Voltage. less than 0.05% by mole based on the content of M'. When the In the positive electrode active material (B), the content of oxide contains Al and/or Sn, the total amount thereof is pref Mg is preferably at least 0.1% by mole, more preferably at erably less than 0.5% by mole, more preferably less than least 0.15% by mole, particularly preferably at least 0.2% by 30 0.2% by mole, particularly preferably less than 0.1% by mole mole, based on the amount of the metal element M', from the based on the content of M'. viewpoint of more effectively attaining the effects of Mg. Furthermore, when the lithium-containing transition metal Herein the content of the metal element M (% by mole) is oxide other than the positive electrode active materials (A) based on the amount of the metal element M' (100% by and (B) is used, the content of Mg in the other metal oxide is mole). 35 preferably at least 0.01% by mole, more preferably at least When the positive electrode active material (B) contains at 0.05% by mole, particularly preferably at least 0.07% by least one metal element selected from Ti, Zr, Ge and Nb, the mole, based on the amount of the metal element M', from the total content thereof is at least 0.05% by mole, more prefer viewpoint of more effectively attaining the effects of Mg. ably at least 0.08% by mole, particularly preferably at least When the lithium-containing transition metal oxide other 0.1% by mole, based on the content of M', from the viewpoint 40 than the positive electrode active materials (A) and (B) con of more effectively attaining the effects of the use of these tains at least one metal element selected from Ti, Zr, Ge and metal elements. When the positive electrode active material Nb, the total content thereof is at least 0.005% by mole, more (B) contains Al and/or Sn, the total content thereof is prefer preferably at least 0.008% by mole, particularly preferably at ably 0.1% by mole or more, more preferably 0.15% by mole least 0.01% by mole, based on the content of M', from the or more, particularly preferably 0.2% by mole or more based 45 viewpoint of more effectively attaining the effects of the use on the content of M', from the viewpoint of more effectively of these metal elements. When the positive electrode active attaining the effects of the use of these metal elements. material (A) contains Al and/or Sn, the total content thereof is When the content of Mg is too large in the positive elec preferably 0.01% by mole or more, more preferably 0.05% by trode active material (B), the load characteristic of the battery mole or more, particularly preferably 0.07% by mole or more tends to decrease. Therefore, the content of Mg is preferably 50 based on the content of M', from the viewpoint of more less than 2% by mole, more preferably less than 1% by mole, effectively attaining the effects of the use of these metal particularly preferably 0.5% by mole, most preferably 0.3% elements. by mole. However, again in the lithium-containing transition metal When the content of Ti, Zr, Ge, Nb, Aland/or Sn is too large oxide other than the positive electrode active materials (A) in the positive electrode active material (B), the effect to 55 and (B), when the content of Mg is too large, the load char increase the capacity of the battery may not be sufficient. acteristic of the battery tends to decrease. Therefore, the Thus, when the oxide contains Ti, Zr, Ge and/or Nb, the total content of Mg is preferably less than 2% by mole, more content thereof is preferably less than 0.5% by mole, more preferably less than 1% by mole, particularly preferably 0.5% preferably less than 0.25% by mole, particularly preferably by mole, most preferably 0.3% by mole, each based on the less than 0.15% by mole based on the content of M'. When the 60 content of M'. oxide contains Al and/or Sn, the total amount thereof is pref Again, in the lithium-containing transition metal oxide erably less than 1% by mole, more preferably less than 0.5% other than the positive electrode active materials (A) and (B), by mole, particularly preferably less than 0.3% by mole based when the content of Ti, Zr, Ge, Nb, Al and/or Sn is too large on the content of M'. in the positive electrode active material (A), the effect to In the positive electrode active material (A), the content of 65 increase the capacity of the battery may not be sufficient. Mg is preferably at least 0.01% by mole, more preferably at Thus, when the oxide contains Ti, Zr, Ge and/or Nb, the total least 0.05% by mole, particularly preferably at least 0.07%by content thereof is preferably less than 0.5% by mole, more Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 64 of 90 PageID: 64 US 9,077,035 B2 9 10 preferably less than 0.25% by mole, particularly preferably characteristics of the battery tend to decrease. Thus, Z is less than 0.15% by mole based on the content of M'. When the preferably less than 5 times as large as c', more preferably oxide contains Al and/or Sn, the total amount thereof is pref less than 4 times as large as c, particularly preferably less than erably less than 1% by mole, more preferably less than 0.5% 3.5 times as large as c. by mole, particularly preferably less than 0.3% by mole based 5 When the three or more lithium-containing transition metal on the content of M'. oxides having the different average particle sizes are con A method for including the metal element M in the posi tained in the positive electrode, there is no especial limitation tive electrode active material (B) or the other lithium-contain on the relationship of the element M content between the ing transition metal oxide(s) is not particularly limited. For positive electrode active material (A) having the largest aver example, the element M” may be present on the particles of 10 age particle size and the other lithium-containing transition the metal oxide, may be evenly present as a Solid Solution metal oxides. Thus, the former may contain a larger amount inside the metal oxides, or may be unevenly present inside the of the element M than the latter, and vise versa, or the metal oxides with having a density distribution. Furthermore, element M' contents in the former and the latter may be the the element M may form a compound which in turn forms a same. In a more preferable embodiment, a metal oxide having layer on the particle surfaces. Preferably, the element M is 15 a smaller average particle size contains a larger amount of the evenly present as a Solid Solution. element M. In particular, when the three lithium-containing In the formulae (1) and (2) representing the positive elec transition metal oxides having different average particle sizes trode active material (B) and the other lithium-containing are used, the element M content in the positive electrode transition metal oxide(s), respectively, the element M is an active material (B) having the Smallestaverage particle size is element other than Li, M' and M. The positive electrode largest, that in lithium-containing transition metal oxide hav active material (B) and the other lithium-containing transition ing the average particle size between those of the active metal oxides may each contain the M in an amount such that materials (A) and (B) is second largest, and that in the positive the advantageous effects of the present invention are not electrode active material (A) having the largest average par impaired, or they may contain no M. ticle size is Smallest. Examples of the element M include alkali metals other 25 In the lithium-containing transition metal oxides which than Li (e.g., Na, K and Rb), alkaline earth metals other than constitute the positive electrode active material according to Mg (e.g., Be, Ca,Sr and Ba), Group IIIa metals (e.g., Sc., Y. the present invention, the oxides having different average La), Group IVa metals other than Ti and Zr (e.g., Hf), Group particle sizes may have the same composition of elements, or Va metals other than Nb (e.g., V and Ta), Group VIa metals different compositions of elements between them. When the (e.g., Cr, Mo and W), Group VIIb metals other than Mn (e.g., 30 lithium-containing transition metal oxides according to the Tc and Re), Group VIII metals other than Co and Ni (e.g., Fe, present invention are the above-mentioned positive electrode Ru, and Rh), Group Ib metals (e.g., Cu, Ag and Au), Group active materials (A) and (B), the following combination may IIIb metals other than Zn and Al (e.g., B, Ca and In), Group be used: a combination of the positive electrode active mate IVb metals other than Sn and Pb (e.g., Si), P and Bi. rial (A) consisting of LiCoooosMgoooosTioooo-AloooosC2. The metal element M contributes to an improvement in the 35 and the positive electrode active material (B) consisting of stability of the lithium-containing transition metal oxides. LiCoo.334Nio.33Mno.33 Mgoloo24Ti.o.o.o.12Alooo24O2. However, when the content thereof is too large, a function of The positive electrode active material comprising the storing and releasing Li ions is impaired so that the battery lithium-containing transition metal oxides according to the characteristics may be decreased. Since the positive electrode present invention is formed through a certain synthesizing active material (B) having the Smallest average particle size 40 process and a certain battery producing process. For example, has the particularly Small particle size and decreased stability, for the preparation of lithium-containing transition metal it is preferable that the content of the element M, which is a oxides which contain Co as the transition metal element M' stabilizing element, is somewhat high. In addition, since the and have different average particle sizes, firstly, a solution of positive electrode active material (B) has the small particle an alkali such as NaOH is dropwise added to an acidic aque size and in turn the large Surface area, it exhibits a high 45 ous Solution containing Co to precipitate Co(OH). In order to activity. Thus, the presence of the element M' in the material homogeneously precipitate Co(OH), Co may be coprecipi (B) has less influence on the function of storing and releasing tated with a different element, and then the coprecipitated Li ions. material is calcined to obtain Co-O. The particle size of the In contrast, the lithium-containing transition metal oxides precipitates can be adjusted by controlling the period for having relatively large particle sizes, that is, the lithium 50 forming the precipitates. The particle size of Co-O after containing transition metal oxides other than the positive calcination is also controlled by the particle size of the pre electrode active material (B), have better stability than the cipitate at this time. positive electrode active material (B). Therefore, the former When the positive electrode active material is synthesized, metal oxides have less necessity to contain the element M conditions such as a mixing condition, calcination tempera than the positive electrode active material (B). Furthermore, 55 ture, calcination atmosphere, calcination time, starting mate their function of storing and releasing Li ions is easily rials, and also battery fabrication conditions are Suitably impaired by the presence of the element M since the mate selected. With regard to the mixing condition in the synthesis rials have the smaller surface area and the lower activity than of the positive electrode active material, preferably, for the positive electrode active material (B). example, ethanol or water is added to the powdery starting Accordingly, it is preferable that the content of the metal 60 materials, and then mixed in a planetary ball mill for 0.5 hour element M in the positive electrode active material (B) is or longer. More preferably, ethanol and water are mixed at a larger than that in the lithium-containing transition metal volume ratio of 50:50, and the mixture is agitated in a plan oxide(s) other than the positive electrode active material (B). etary ball mill for 20 hours or longer. Through this mixing That is, Zin the formula (1) is preferably larger than c in the step, the powdery starting materials are sufficiently commi formula (2) (ZDc). In particular, Z is at least 1.5 times, more 65 nuted and mixed to prepare a homogeneous dispersion. The preferably at least 2 times, particularly preferably at least 3 dispersion is dried with a spray drier or the like while keeping times larger than c. When Z is much larger than c, the load homogeneity. The calcination temperature is preferably from Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 65 of 90 PageID: 65 US 9,077,035 B2 11 12 750 to 1,050° C., more preferably from 950 to 1,030°C. The having different average particle sizes, for example, the posi calcination atmosphere is preferably an air. The calcination tive electrode active materials (A) and (B), are mixed with time is preferably from 10 to 60 hours, more preferably from each other at a predetermined weight ratio. If necessary, an 20 to 40 hours. electric conductive aid (e.g., graphite, carbon black, acety In the preparation of the positive electrode active material, lene black, etc.) is added to the mixture. Furthermore, to the LiCO is preferably used as a lithium source. As the sources mixture, a binder (e.g., polyvinylidene fluoride, poly tet of other metal such as Mg, Ti, Ge, Zr, Nb, Aland Sn, preferred rafluoroethylene, etc.) is added to prepare a positive electrode are nitrates or hydroxides of these metals, or oxides thereof mixture. A solvent is used to formulate this positive electrode having a particle size of 1 um or less. It is preferable to use the mixture in the form of a paste. The binder may be mixed with coprecipitate of the hydroxides since the different elements 10 the positive electrode active material and the like after the are uniformly distributed in the active material. binder is dissolved in a solvent. In this way, the paste con The contents of the metal elements in the positive electrode taining the positive electrode mixture is prepared. The result active materials are measured by the ICP atomic emission ant paste is applied to a positive electrode current collector spectroscopy or the like. The content of lithium can be mea made of an aluminum foil or the like, and then dried to form Sured by an atomic absorption analysis. In the state of a 15 a positive electrode mixture layer. If necessary, the layer is positive electrode, it is difficult to separately measure the pressed to obtain a positive electrode. However, the method contents of the metal elements in each of the positive elec for producing the positive electrode is not limited to the trode active material having a larger particle size and one above-mentioned method, and may be any other method. having a smaller particle size. Therefore, the contents or The positive electrode mixture layer according to the content ratios of the metal elements of the positive electrode present invention may have a density of 3.5 g/cm or more, active material having different particle sizes may be mea more preferably 3.6 g/cm or more, particularly preferably Sured with an electron prove microanalyzer using a mixture of 3.8 g/cm or more. With such a density, the capacity of the positive electrode active materials having a known mixing battery can be increased. However, when the density of the ratio as a standard sample. Alternatively, the positive elec positive electrode mixture layer is too high, the wettability trode is treated with a suitable solvent such as N-methyl-2- 25 with the nonaqueous electrolyte, which will be explained pyrrolidone (NMP) to separate the active material particles later, decreases. Thus, the density is preferably 4.6 g/cm or from the positive electrode and settled out in the solvent, less, more preferably 4.4 g/cm or less, particularly prefer followed by washing and drying. Then, the particle size dis ably 4.2 g/cm or less. tribution of the recovered particles is measured and the peak Herein, the density of the positive electrode mixture layer separation of the particle size distribution curve is carried out. 30 may be obtained by the following measuring method: The When the inclusion of two or more particles having different positive electrode is cut to form a sample piece having a particle sized is confirmed, the particles are classified into a predetermined area, the sample piece is weighed with an larger one and a smaller one, and the contents of the metal electronic balance having a minimum scale of 1 mg, and then elements in each particle group are measured by the ICP the weight of the current collector is subtracted from the atomic emission spectroscopy. 35 weight of the sample piece to calculate the weight of the Herein, the contents of the metal elements in the positive positive electrode mixture layer. The total thickness of the electrode active material may be measured by the ICP atomic positive electrode is measured atten points with a micrometer emission spectroscopy as follows: about 5 g of the active having a minimum scale of 1 Lum. Then, the thickness of the material is precisely weighed and charged in a 200 ml beaker. current collector is subtracted from the resultant individual Then, 100 ml of aqua regia is added, and the mixture is 40 thicknesses, and the thicknesses of the positive electrode concentrated by heating to a liquid volume of about 20 to 25 mixture layer measured at ten points are averaged. From the ml. After cooling, the mixture is filtrated through a quantita averaged thicknesses of the positive electrode mixture layer tive filter paper (No. SB available from Advantec MFS, Inc.) and the surface area, the volume of the positive electrode to separate the solids. The filtrate and washing liquid are mixture layer is calculated. Finally, the weight of the positive charged in a 100 ml measuring flask and diluted to a specific 45 electrode mixture layer is divided by the volume thereof to Volume. Then, the contents of the metal elements in the solu obtain the density of the positive electrode mixture layer. tion are measured with a sequential type ICP analyzer (IPIS The thickness of the positive electrode mixture layer is 1000 manufactured by Nippon Jarrel-Ash Co., Ltd.). preferably from 30 to 200 um, and the thickness of the current When the content (I) of at least one metal element selected collector used in the positive electrode is preferably from 8 to from the group consisting of Mg, Ti, Zr, Ge, Nb, Al and Sn in 50 20 Lum. the transition metal oxide having the Smallestaverage particle In the positive electrode mixture layer, the content of the size and a content (II) of the same metal element as one with lithium-containing transition metal oxides as the active mate which the content (I) in the lithium-containing transition rials is preferably 96% by weight or more, more preferably metal oxide other than one having the Smallest average par 97% by weight or more, particularly preferably 97.5% by ticle size are measured by the ICP atomic emission spectros 55 weight or more, while it is preferably 99% by weight or less, copy described above, the ratio of the content (I) to the con more preferably 98% by weight or less. The content of the tent (II) corresponds to the relationship between Z in the binder in the positive electrode mixture layer is preferably 1% formula (1) and c in the formula (2). The ratio of the content by weight or more, more preferably 1.3% by weight or more, (I) to the content(II) is preferably at least 1.5, more preferably particularly preferably 1.5% by weight or more, while it is at least 2, particularly preferably at least 3. Since the load 60 preferably 4% by weight or less, more preferably 3% by characteristics of the battery tend to decrease when Z is much weight or less, particularly preferably 2% by weight or less. larger than c, the ratio of the content (I) to the content (II) is The content of the electric conductive aid in the positive preferably less than 5, more preferably less than 4, particu electrode mixture layer is preferably 1% by weight or more, larly preferably less than 3.5. more preferably 1.1% by weight or more, particularly pref The positive electrode used in the present invention is 65 erably 1.2% by weight or more, while it is preferably 3% by formed by, for example, a method described below. Firstly, weight or less, more preferably 2% by weight or less, particu the two or more lithium-containing transition metal oxides larly preferably 1.5% by weight or less. Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 66 of 90 PageID: 66 US 9,077,035 B2 13 14 When the content of the active material in the positive characteristics tend to decrease. When the specific surface electrode mixture layer is too small, the capacity cannot be area is too large, the graphite easily reacts with the electrolyte increased and also the density of the positive electrode mix and Such a reaction may have influences on the properties of ture layer cannot be increased. When this content is too large, the battery. the resistance may increase or the formability of the positive The graphite used in the negative electrode is preferably electrode may be impaired. When the binder content in the made of natural graphite. More preferred is a mixture of two positive electrode mixture layer is too large, the capacity may or more graphite materials having different Surface crystal hardly be increased. When this content is too small, the adhe linity to achieve the high density of the negative electrode. sion of the layer to the current collector decreases so that the Since natural graphite is inexpensive and achieves a high powder may drop off from the electrode. Thus, the above 10 mentioned preferable ranges are desirable. Furthermore, capacity, the negative electrode with a high cost performance when the content of the electric conductive aid in the positive can be produced. Usually, when natural graphite is used, the electrode mixture layer is too large, the density of the positive battery capacity is easily decreased as the density of the electrode mixture layer may not be made Sufficiently high so negative electrode is increased. However, the decrease in the that the capacity may hardly be increased. When this content 15 battery capacity can be suppressed by mixing the natural is too small, the Sufficient electric conduction through the graphite with a graphitehaving a reduced Surface crystallinity positive electrode mixture layer is not attained so that the by a Surface treatment. charge-discharge cycle characteristic or the load characteris The surface crystallinity of specific graphite can be deter tic of the battery may deteriorated. mined by the Raman spectrum analysis. When the R value of It is essential for the nonaqueous secondary battery of the the Raman spectrum (R-Iso/Isso, that is, the ratio of the present invention to have the positive electrode explained Raman intensity around 1350 cm to that around 1580 cm) above, and thus there is no specific limitation on other ele is 0.01 or more, where the Raman spectrum is measured with ments or structure of the battery. The battery of the present graphite which has been excited with an argon laser having a invention may adopt various elements and structures, which wavelength of 514.5 nm, the surface crystallinity of the spe are commonly adopted in the conventional nonaqueous sec 25 cific graphite is slightly lower than that of natural graphite. ondary batteries in the state of art. Thus, with the graphite having a Surface crystallinity The negative electrode active material in the negative elec decreased by the surface treatment, the R value is preferably trode may be any material that can be doped and de-doped 0.01 or more, more preferably 0.1 or more, while it is prefer with Li ions. Examples thereof are carbonaceous materials ably 0.5 or less, more preferably 0.3 or less. The content of the Such as graphite, pyrolytic carbons, cokes, glassy carbons, 30 graphite having a surface crystallinity decreased by Surface burned bodies of organic polymers, mesocarbon microbeads, treatment is preferably 100% by weight of the whole graphite carbon fibers and activated carbon. In addition, the following in order to increase the density of the negative electrode. materials can also be used as the negative electrode active However, in order to prevent the decrease of the battery material: alloys of Si, Sn, In or the like, oxides of Si, Snor the capacity, the content of such graphite is preferably 50% by like that can be charged and discharged at a low Voltage near 35 weight or more, more preferably 70% by weight or more, a voltage at which Li can be charged and discharged, and particularly preferably 85% by weight or more of the whole nitrides of Li and Co such as Li CoolN. Graphite can be graphite. partially substituted with a metal, a metal oxide or the like that When the average particle size of the graphite is too small, can be alloyed with Li. When graphite is used as the negative an irreversible capacity increases. Thus, the average particle electrode active material, the voltage when the battery is fully 40 size of the graphite is preferably 5 um or more, more prefer charged can be regarded as about 0.1 V with reference to the ably 12 um or more, particularly preferably 18 um or more. potential of lithium, and therefore the voltage of the positive From the viewpoint of the increase of the capacity of the electrode can be conveniently calculated as a Voltage obtained negative electrode, the average particle size of the graphite is by adding 0.1 V to the battery voltage. Consequently, the 30 um or less, more preferably 25 um or less, particularly charge Voltage of the positive electrode is easily controlled. 45 preferably 20 um or less. Preferably, graphite has such a form in that a lattice spacing The negative electrode may be produced by the following do of the (002) planes is 0.338 nm or less, since the negative method, for example: The negative electrode active material electrode or a negative electrode mixture layer, which will be and an optional a binder and/or other additives are mixed to explained later, has a higher density as the crystallinity is prepare a negative electrode mixture, and the mixture is dis higher. However, when the lattice spacing doo is too large, the 50 persed in a solvent to prepare a paste. Preferably, the binder is high density negative electrode may decrease the discharge dissolved in a solvent prior to mixing with the negative elec characteristic or the load characteristic of the battery. Thus, trode active material, and then mixed with the negative elec the lattice spacing doo is preferably 0.335 nm or more, more trode active material and so on. The paste containing the preferably 0.3355 nm or more. negative electrode mixture is applied to a negative electrode The crystal size of the graphite in the c axis direction (Lc) 55 current collector made of a copper foil or the like, and then is preferably 70 nm or more, more preferably 80 nm or more, dried to form a negative electrode mixture layer. The layer is particularly preferably 90 nm or more. As the Lc is larger, the pressed to obtain a negative electrode. However, the method charging curve becomes flat so that the Voltage of the positive for producing the negative electrode is not limited to the electrode is easily controlled and also the capacity can be above-mentioned method, and may be any other method. made large. When the Lc is too large, the battery capacity 60 The density of the negative electrode mixture layer after tends to decrease with the high-density negative electrode. pressing is preferably 1.70 g/cm or more, more preferably Thus, the Lc is preferably less than 200 nm. 1.75 g/cm or more. Based on the theoretical density of graph Furthermore, the specific surface area of the graphite is ite, the upper limit of the density of the negative electrode preferably 0.5 m/g or more, more preferably 1 m/g or more, mixture layer formed using graphite is 2.1 to 2.2 g/cm. The particularly preferably 2 m/g or more, while it is preferably 65 density of the negative electrode mixture layer is preferably 6 m/g or less, more preferably 5 m/g or less. Unless the 2.0 g/cm or less, more preferably 1.9 g/cm or less from the specific Surface area of the graphite is somewhat large, the viewpoint of the affinity with the nonaqueous electrolyte. It is Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 67 of 90 PageID: 67 US 9,077,035 B2 15 16 preferable to press the negative electrode plural times since bonate; and mixed solvents comprising an acyclic ester and a the negative electrode can be uniformly pressed. cyclic ester. Mixed solvents each comprising an acyclic ester The binder used in the negative electrode is not particularly as a main solvent and a cyclic ester are particularly Suitable. limited. For the increase of the content of the active material Apart form the esters exemplified above, the following to increase the capacity, the amount of the binder is preferably Solvents may also be used: acyclic phosphoric acid triesters made as small as possible. To this end, the binder is preferably Such as trimethyl phosphate; ethers such as 1,2-dimethoxy a mixture of an aqueous resin which can be dissolved or ethane, 1,3-dioxolane, tetrahydrofuran, 2-methyl-tetrahydro dispersed, and a rubbery polymer, since the use of only a furan and diethyl ether, nitrites and dinitriles; isocyanates; Small amount of the aqueous resin can contribute to the dis and halogen-containing solvents. Furthermore, amine or persion of the graphite and thus prevents the delamination of 10 the negative electrode mixture layer from the current collec imide organic solvents may be used. tor caused by the expansion and contraction of the electrode Furthermore, the nonaqueous electrolytic Solution may in the charge-discharge cycles. contain a fluorine-containing organic solvent, which can Examples of the aqueous resins include cellulose resins improve the stability of the battery since it forms a surface Such as carboxymethylcellulose, and hydroxypropylcellu 15 protective film on the positive electrode active materials dur lose, and polyvinylpyrrolidone, polyepichlorohydrin, polyvi ing charging. More preferably, a fluorine-containing organic nylpyridine, polyvinyl alcohol, polyether resins such as poly Solvent having a carbon-carbon double bond may be used in ethylene oxide and polyethylene glycol, etc. Examples of the combination with other usual fluorine-containing organic Sol rubbery polymers include latex, butyl rubber, fluororubber, vent. Specific examples of the fluorine-containing organic styrene-butadiene rubber, nitrile-butadiene copolymer rub solvent include HFE7100 (CFOCH), F-DPC CFCHO ber, ethylene-propylene-diene copolymer (EPDM), polyb (C=O)OCHCF), F-DEC CFCHO(C=O)OCHCF), utadiene, etc. From the viewpoint of the dispersibility of the fluorobenzene, fluoroethylene carbonate ( OCH graphite particles and the prevention of delamination of the CHFO-(C=O), ( OCHF CHFO-)C=O, etc.), and the layer, it is preferable to use a cellulose ether compound Such like. The amount of such a solvent added is preferably at least as carboxymethylcellulose together with abutadiene copoly 25 0.1% by weight, more preferably at least 2% by weight, mer rubber such as a styrene-butadiene rubber. It is particu particularly preferably at least 5% by weight, while it is larly preferable to use carboxymethylcellulose together with preferably 30% by weight or less, more preferably 20% by a butadiene copolymer rubber Such as a styrene-butadiene weight or less, particularly preferably 15% by weight or less, copolymer rubber or a nitrile-butadiene-copolymer rubber. based on the whole weight of the electrolyte. When the The cellulose ether compound such as carboxymethylcellu 30 lose mainly has a thickening effect on the paste containing the amount of Such a solvent is too large, the electric character negative electrode mixture, while the rubbery polymer such istics of the battery tend to decrease. When it is too small, any as the styrene-butadiene copolymer rubber has a binding good protective film may not be formed. effect on the negative electrode mixture. When the cellulose The nonaqueous electrolyte may contain a Sulfur-contain ether compound Such as carboxymethylcellulose and the rub 35 ing organic solvent, which can improve the stability of the bery polymer Such as the styrene-butadiene copolymer rub battery since it forms a surface protective film on the positive ber are used in combination, the weight of the former to the electrode active materials during charging. The Sulfur-con latter is preferably from 1:1 to 1:15. taining organic solvent is preferably an organic compound The thickness of the negative electrode mixture layer is having —O—SO - bond, more preferably one having a preferably from 40 to 200 um. The thickness of the current 40 —O SO. O—bond. Specific examples of such a solvent collector used in the negative electrode is preferably from 5 to include sulfone, methylsulfolane, methylethylene sulfate, 30 um. 1,3-propanesulfone, diethyl sulfate, butyl sulfate, butylsul In the negative electrode mixture layer, the content of the fone, diphenyldisulfide, etc. The amount of such a solvent is binder or binders is preferably 1.5% by weight or more, more preferably at least 0.1% by weight, more preferably at least preferably 1.8% by weight or more, particularly preferably 45 1% by weight, particularly preferably at least 2% by weight, 2.0% by weight or more of the layer, while it is preferably less while it is preferably 10% by weight or less, more preferably than 5% by weight, less than 3% by weight, less than 2.5% by 5% by weight or less, particularly preferably 3% by weight or weight. When the amount of the binder in the negative elec less, based on the whole weight of the electrolyte. When the trode mixture layer is too large, the discharge capacity of the amount of Such a solvent is too large, the electric character battery may decrease. When the amount is too small, the 50 istics of the battery tend to decrease. When it is too small, any adhesion between the particles decreases. The content of the good protective film may not be formed. negative electrode active material in the negative electrode Furthermore, the nonaqueous electrolytic Solution may mixture layer is preferably more than 95% by weight and preferably contain a nonionic aromatic compound. Specific 98.5% by weight or less. examples thereof include aromatic compounds having an In the nonaqueous secondary battery of the present inven 55 alkyl group bonded to an aromatic ring (e.g., cyclohexylben tion, the nonaqueous electrolyte is preferably a nonaqueous Zene, isopropylbenzene, tert-butylbenzene, tert-amylben Solvent-base electrolytic solution comprising an electrolyte Zene, octylbenzene, toluene and Xylene); aromatic com salt Such as a lithium salt dissolved in a nonaqueous solvent pounds having a halogen group bonded to an aromatic ring Such as an organic solvent, from the viewpoint of electric (e.g., fluorobenzene, difluorobenzene, trifluorobenzene and characteristics or handling easiness. A polymer electrolyte or 60 chlorobenzene); aromatic compounds having an alkoxy a gel electrolyte may be used without any problem. group bonded to anaromatic ring (e.g., anisole, fluoroanisole, The solvent in the nonaqueous electrolytic solution is not dimethoxybenzene and diethoxybenzene); aromatic car particularly limited, and examples thereof include acyclic boxylic acid esters such as phthalic acid esters (e.g., dibutyl esters such as dimethyl carbonate, diethyl carbonate, ethyl phthalate and di-2-ethylhexyl phthalate) and benzoic acid methyl carbonate, and methyl propyl carbonate; cyclic esters 65 esters; carbonic acid esters having a phenyl group (e.g., meth having a high dielectric constant, such as ethylene carbonate, ylphenyl carbonate, butylphenyl carbonate and diphenyl car propylene carbonate, butylene carbonate, and vinylene car bonate); phenyl propionate; and biphenyl. Among them, the Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 68 of 90 PageID: 68 US 9,077,035 B2 17 18 compounds having an alkyl group bonded to an aromatic ring tecting coating may contain either fluorine atoms or Sulfur (alkaryl compounds) are preferred, and cyclohexylbenzene is atoms. Preferably, the coating contains both of fluorine atoms particularly preferred. and Sulfur atoms. The aromatic compounds exemplified above can form a The amount of the Sulfur atoms in the Surface protecting film on the surface of the active material in the positive 5 coating formed on the positive electrode active material Sur electrode or the negative electrode in the battery. These aro face is preferably 0.5 atomic '% or more, more preferably 1 matic compounds may be used alone, while more advanta atomic '% or more, particularly preferably 3 atomic '% or geous effects can be attained by the use of two or more of the more. However, when the amount of the sulfur atoms in the aromatic compounds together. Particularly advantageous positive electrode active material Surface is too large, the effects can be attained on the improvement of the safety of the 10 discharge characteristic of the battery tends to decrease. Thus, battery by the use of the alkaryl compound together with an the amount is preferably 20 atomic 96 or less, more preferably aromatic compound, which can be oxidized at a lower Voltage 10 atomic '% or less, particularly preferably 6 atomic 96 or than the alkaryl compound, Such as biphenyl. less. The method for adding the aromatic compound in the non The amount of the fluorine atoms in the Surface protecting aqueous electrolytic Solution is not particularly limited. In 15 coating formed on the positive electrode active material Sur general, the aromatic compound is added to the nonaqueous face is preferably 15 atomic 96 or more, more preferably 20 electrolytic solution prior to the fabrication of the battery. atomic '% or more, particularly preferably 25 atomic '% or The content of the aromatic compound in the nonaqueous more. However, when the amount of the fluorine atoms in the electrolytic solution is preferably 4% by weight or more from positive electrode active material Surface is too large, the the viewpoint of the safety, and it is preferably 10% by weight 20 discharge characteristic of the battery tends to fall. Thus, the or less from the viewpoint of the load characteristic. When amount of the fluorine atoms is preferably 50 atomic '% or two or more aromatic compounds are used together, the total less, more preferably 40 atomic '% or less, particularly pref amount thereof is within the above-mentioned range. When erably 30 atomic '% or less. The Surface protecting coating, the alkaryl(alkylaryl) compound and the aromatic compound which contains the fluorine atoms and/or the Sulfur atoms, in which can be oxidized at a lower voltage that the alkaryl 25 the positive electrode active material may not be formed by compound are used in combination, the content of the alkaryl charging the battery as described above, but the positive elec compound in the nonaqueous electrolytic solution is prefer trode (battery) may be formed by the use of the positive ably 0.5% by weight or more, more preferably 2% by weight electrode active material, that is, the lithium-containing tran or more, while it is preferably 8% by weight or less, more sition metal oxides, which has such a Surface protecting coat preferably 5% by weight or less. The content of the aromatic 30 ing already formed. compound that can be oxidized at a lower Voltage than the In order to improve the charge-discharge cycle character alkaryl compound in the nonaqueous electrolytic solution is istic of the battery, preferably, the nonaqueous electrolytic preferably 0.1% by weight or more, more preferably 0.2% by Solution contains at least one carbonate compound selected weight or more, while it is preferably 1% by weight or less, from the group consisting of vinylene carbonates, such as more preferably 0.5% by weight or less. 35 ( OCH=CHO )C=O, ( OCH=C(CH)O )C=O Furthermore, a Surface protecting coating can beformed on and ( OC(CH)—C(CH)O )C—O, and derivatives the surface of the positive electrodeactive material in the step thereof; and fluorine-substituted ethylene carbonates, such as of initial charging of the battery, when the nonaqueous elec ( OCH CHFO )C=O and ( OCHF CHFO ) trolytic Solution contains at least one compound selected C—O. The addition amount thereof is preferably 0.1% by from the group consisting of halogen-containing organic Sol- 40 weight or more, more preferably 0.5% by weight or more, vents (e.g., halogen-containing carbonates), fluorine-con particularly preferably 2% by weight or more based on the taining organic lithium salts, phosphorus-containing organic whole weight of the nonaqueous electrolytic solution. When Solvents, silicon-containing organic solvents, nitrogen-con the addition amount thereof is too large, the load character taining organic solvents, etc. Specific examples thereof istic of the battery tends to decrease. Thus, the addition include F-DPC CFCHO(C=O)CCHCF), F-DEC 45 amount is preferably 10% by weight or less, more preferably CFCHO(C=O)OCHCF, HFE7100 (CFOCH), butyl 5% by weight or less, particularly preferably 3% by weight or sulfate (CHOSOOCH), methylethylene sulfate less based on the whole weight of the nonaqueous electrolytic ( OCH(CH)CHO )SO), butyl sulfate Solution. (CHSOCH), a polymer imide salt (I N(Li)SOOCH Examples of the electrolyte salt to be dissolved in the (CF). CHOSO I, wherein n is from 2 to 100), 50 Solvent during the preparation of the nonaqueous electrolytic (CFSO)NLi, and (CF)2CHOSO-NLi. solution include LiClO, LiPF LiBF LiAsF, LiSbF. Such additives may be used alone. It is particularly prefer LiCFSO, LiCFSO, LiCFCO, LiCF (SO), LiN able to use a fluorine-containing organic solvent together with (RfSO)(Rf'SO), LiC(RfSO), LiCFSO wherein na2. a fluorine-containing organic lithium salt. The amount of and LiN(RfCSO), wherein Rf and Rf each represent a fluo such an additive added is preferably 0.1% by weight or more, 55 roalkyl group. They may be used alone or in combination of more preferably 2% by weight or more, particularly prefer two or more thereof. Among these electrolyte salts, particu ably 5% by weight or more, while it is preferably 30% by larly preferred are fluorine-containing organic lithium salts weight or less, more preferably 10% by weight or less, each having 2 or more carbon atoms, since such lithium salts have based on the whole weight of the nonaqueous electrolytic a large anionic property and further ion separation easily solution. When the amount of the additive is too large, the 60 occurs so that the salts are easily dissolved in the above electric characteristics of the battery may deteriorate. When mentioned solvents. The concentration of the electrolyte salt the amount is too small, a good coating may hardly beformed. in the nonaqueous electrolytic solution is not particularly When the battery comprising the nonaqueous electrolytic limited, and it is preferably 0.3 mol/L or more, more prefer Solution containing the above-mentioned additive(s) is ably 0.4 mol/L or more, while it is preferably 1.7 mol/L or charged, particularly at a high Voltage, a Surface protecting 65 less, more preferably 1.5 mol/L or less. coating that contains fluorine or Sulfur atoms is formed on the In the present invention, the nonaqueous electrolyte may be positive electrode active material surface. This surface pro a gel-form polymer electrolyte besides the nonaqueous elec Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 69 of 90 PageID: 69 US 9,077,035 B2 19 20 trolytic solution described above. The gel-form polymer elec The ratio of the tensile strength in TD to that in MD (tensile trolyte corresponds to a product obtained by the gelation of strength in TD/tensile strength in MD) is preferably 0.95 or the nonaqueous electrolytic Solution with a gelling agent. For less, more preferably 0.9 or less, while it is preferably 0.1 or the gelation of the nonaqueous electrolytic solution, the fol more. The transverse direction means a direction perpendicu lowing gelling agents may be used: a linear polymer Such as lar to the direction in which the film resin for the production polyvinylidene fluoride, polyethylene oxide or polyacryloni of the separator is wound up, that is, the machine direction. trile, or a copolymer thereof, or a polyfunctional monomer The puncture strength of the separator is preferably 2.0 N which can be polymerized by irradiation with actinic rays or more, more preferably 2.5 N or more. As this value is Such as ultraviolet rays or electron beams (e.g., an acrylate higher, the battery is less easily short-circuited. Usually, how having 4 or more functionalities such as pentaerythritol tet 10 raacrylate, ditrimethylolpropane tetraacrylate, ethoxylated ever, the upper limit thereof is substantially determined by the pentaerythritol tetraacrylate, dipentaerythritol hydroxypen material of the separator. In the case of a separator made of taacrylate, or dipentaerythritol hexaacrylate; or a methacry polyethylene, the upper limit of the puncture strength is about late having 4 or more functionalities, which are analogous to 10 N. Here, a puncture strength is measured by cutting a the above acrylates. In the case of the monomer, the monomer 15 sample piece of 50 mmx50 mm from a separator, clamping itself does not cause the gelling of the electrolytic solution, the sample piece with jigs at the edges of 5 mm, puncturing but the polymer formed from the monomer acts as a gelling the sample piece with a needle having a tip end with a radius agent. of 0.5 mm at a rate of 2 mm/sec., and measuring a maximum When a polyfunctional monomer is used to gel the electro load before the puncture of the sample piece as a puncture lytic Solution as described above, a polymerization initiator strength. may optionally be used. Examples of the polymerization When a conventional nonaqueous secondary battery is initiator include benzoyls, benzoin alkyl ethers, benzophe charged at a high positive electrode voltage of 4.35 V or nones, benzoylphenylphosphine oxides, acetophenones, higher with reference to the potential of lithium and is dis thioxanthones and anthraquinones. As a sensitizer for the charged to a final Voltage higher than 3.2 V, the crystalline polymerization initiator, an alkylamine oran aminoester may 25 structure of the positive electrode active material decays to be used. decrease the capacity or to induce heating of the battery due to In the present invention, the nonaqueous electrolyte may be the deterioration of the thermal stability. Thus, the battery a solid electrolyte besides the nonaqueous electrolytic solu may not be practically used. When a positive electrode active tion or the gel-form polymer electrolyte. The solid electrolyte material to which a different element such as Mg or Ti is may be an inorganic Solid electrolyte or an organic Solid 30 added is used, the decrease of the safety or of the capacity electrolyte. over charge-discharge cycles can be suppressed, but the In the present invention, a separator used in the present degree of suppression is not sufficient. Moreover, the filling invention preferably has a thickness of 5 um or more, more of the positive electrode is insufficient so that the battery preferably 10 um or more, particularly preferably 12 um or easily expands. more, while it is preferably less than 25um, more preferably 35 In contrast, the battery of the present invention having the less than 20 Lum, particularly preferably less than 18 um, from structure explained above is a nonaqueous secondary battery the viewpoint of imparting the directionality of the tensile which improves the capacity, the charge-discharge cycle strength to the separator, keeping good insulating properties characteristic, the safety and the Suppression of expansion of and reducing the thermal shrinkage of the separator. The gas the battery. These advantageous effects can be attained at a permeability of the separator is preferably 500 second/100 40 usual charging Volt (a battery Voltage of 4.2V). Furthermore, mL or less, more preferably 300 second/100-mL or less, when the positive electrode is charged up to a high Voltage of particularly preferably 120 second/100-mL or less. As the gas 4.35 V with reference to the potential of lithium (i.e., a battery permeability of the separator is Smaller, the load characteris voltage of 4.25 V) and then the discharge of the battery is tic is made better but an inside short-circuit is more easily terminated at a high Voltage, that is, a battery Voltage of 3.2V caused. Thus, the gas permeability is preferably 50 second/ 45 or higher, the crystalline structures of the positive electrode 100-mL or more. Here, a gas permeability is measured active materials are very stable so that the decrease of the according to JISP8117. As the thermal shrinkage factor of the capacity or thermal stability is prevented. separator in the transverse direction (TD) is Smaller, an inside Moreover, the positive electrode active material of any short-circuit is less easily caused when the temperature of the conventional nonaqueous secondary battery generates a low battery rises. Thus, the thermal shrinkage factor in TD of the 50 average Voltage. Therefore, when a charge-discharge cycle separator is as Small as possible. The thermal shrinkage factor test is repeated under a condition that the discharge final in TD is preferably 10% or less, more preferably 5% or less. voltage of a unit cell is 4.35 V or higher with reference to the In order to restrain the thermal shrinkage of the separator, it is potential of lithium, the positive electrode is doped or preferable to thermally treat the separator in advance at a dedoped with a large amount of Li ions. This situation is temperature of about 100 to 125° C. The separator having 55 analogous to a case where the battery is subjected to a charge such a thermal shrinkage factor is preferably combined with discharge cycle test under an overcharge condition. Under the positive electrode materials according to the present Such a severe condition, any conventional positive electrode invention to fabricate a battery, since the behaviors of the active material cannot maintain its crystalline structure so as battery at high temperature become stable. to cause disadvantages Such that the thermal stability declines The thermal shrinkage factor in TD of the separator means 60 or the charge-discharge cycle life is shortened. To the con the shrinkage factor of a portion thereof that most largely trary, the use of the positive electrode active materials accord shrinks in TD when the separator having a size of 30 mm ing to the battery of the present invention can overcome Such square is allowed to stand at 105°C. for 8 hours. disadvantages of the conventional positive electrode active With regard to the strength of the separator, a tensile material. Thus, the present invention provides a nonaqueous strength in the machine direction (MD) is preferably 6.8x10 65 secondary battery which can be reversibly charged and dis N/m or more, more preferably 9.8x107 N/m or more. The charged even at a high Voltage. Such as a Voltage of 4.35 to 4.6 tensile strength in TD is preferably smaller than that in MD. V with reference to the potential of lithium. Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 70 of 90 PageID: 70 US 9,077,035 B2 21 22 The nonaqueous secondary battery of the present invention ICP atomic emission spectroscopy, the results of which con has characteristics including a high Voltage, a high capacity firmed that they had the above elementary compositions. and a high safety. By making use of Such characteristics, the The resultant paste was charged in a planetary mixer, and nonaqueous secondary battery of the present invention can be then a 10 wt.% solution of PVDF in NMP, and NMP were used as a power source of a notebook personal computer, a added to dilute the paste, thereby adjusting the viscosity of the stylus-operated personal computer, a pocket personal com paste at a level sufficient for application. This diluted paste puter, a notebook word processor, a pocket word processor, an containing the positive electrode active material mixture was electronic book player, a cellular phone, a codeless handset, a passed through a 70-mesh net to remove large Substances. pager, a portable terminal, a portable copier, an electrical Thereafter, the paste was uniformly applied to both surfaces notebook, an electronic Calculator, a liquid crystal television 10 of a positive electrode current collector made of an aluminum set, an electric shaver, an electric power tool, an electronic foil with a thickness of 15um, and then dried to form film translating machine, an automobile telephone, a transceiver, a form positive electrode mixture layers. In the dried positive Voice input device, a memory card, a backup power source, a electrode mixture layers, the weight ratio of the positive elec tape recorder, a radio, a headphone stereo, a handy printer, a trode active material/the electric conduction aiding agent/ handy cleaner, a portable CD player, a video movie, a navi 15 PVDF was 97.3:1.5:1.2. Thereafter, the resultant sheet was gation system, a refrigerator, an air conditioner, a television, pressed and cut out in a predetermined size. To the cut piece, a stereo, a water heater, a microwave oven, a dishwasher, a a lead member made of aluminum was welded to form a Washing machine, a drying machine, a game equipment, a sheet-form positive electrode. The density of the pressed lighting equipment, a toy, a sensor equipment, a load condi positive electrode mixture layers (the density of the positive tioner, a medical machine, an automobile, an electric vehicle, electrode) was 3.8 g/cm. The thickness of the positive elec a golf cart, an electrically-powered cart, a security system, a trode mixture layers (the total thickness of the layers on both power storing system, or the like. The battery can be used not the Surfaces, i.e., the thickness obtained by Subtracting the only for the consumer applications but also for aerospace thickness of the aluminum foil layer of the positive electrode applications. The capacity-increasing effect of the present current collector from the total thickness of the positive elec invention is enhanced, in particular, in Small-sized portable 25 trode) was 135um. devices. Thus, the battery of the present invention is used in a The particle size distribution of the mixture of the positive portable device desirably having a weight of 3 kg or less, electrode active materials (A) and (B) was measured by a more desirably 1 kg or less. The lower limit of the weight of MICROTRAC particle size analyzer (HRA 9320 available the portable device is not particularly limited. However, the from NIKKISO Co., Ltd.). The result is shown in the graph of lower limit is desirably a value equal to the weight of the 30 FIG.1, which confirm that the mixture contained two kinds of battery, for example, 10 g or more in order to attain the the particles having an average particle size of about 5um and advantageous effects to some degree. 12 um, respectively. In the positive electrode active material (A), the amount of EXAMPLES Mg was 0.08% by mole, that of Ti was 0.04% by mole, and 35 that of Al was 0.08% by mole, each based on the amount of The present invention will be described in detail with ref Co. An electron prove X-ray microanalyzer (EMPA 1600 erence to the following Examples; however, the Examples do manufactured by Shimadzu Corporation) was used to mea not limit the scope of the present invention. Thus, modifica sure the concentration of the metal element M in cross sec tions of the examples are encompassed by the scope of the tions of the particles. As a result, no difference in the concen present invention as long as the modifications do not depart 40 tration of each of Mg, Ti and Al was observed between the from the subject matter of the present invention, which has Surface portion and the core portion. been described above or will be described hereinafter. In the positive electrode active material (B), the amount of Mg was 0.24% by mole, that of Ti was 0.12% by mole, and Example 1 that of Al was 0.24% by mole, each based on the amount of 45 Co. The concentration of the metal element M in the cross Production of Positive Electrode sections of the particles was measured in the same manner as in the case of the positive electrode active material (A). As a The lithium-containing positive electrode materials, result, no difference in the concentration of each of Mg, Ti LiCoooosMgoooosTio ooo-AloooosC2 (average particle size: and Al was observed between the surface portion and the core 12 um) as a positive electrode active material (A), and 50 portion. LiCoooo.4Mgo-oo:24Ti.o.o.o. 2Alooo24O2 (average particle size: 5 With regard to the contents of the metal elements M, the um) as a positive electrodeactive material (B) at a weight ratio molar contents of Mg, Ti and Al in the positive electrode of 65:35 were mixed. Then, 97.3 parts by weight of the active material (B) were 3 times larger, 3 times larger and 3 mixture and 1.5 parts by weight of a carbonaceous material as times larger, respectively, than those in the positive electrode an electric conductive aid were charged in a Volumetric feeder 55 active material (A). as a device for Supplying powder. An amount of a 10 wt.% solution of polyvinylidene fluoride (PVDF) in N-methyl-2- Production of Negative Electrode pyrrolidone (NMP) to be supplied to the feeder was adjusted to control a solid content in the mixture constantly at 94% by As negative electrode active materials, 70 parts by weight weight during kneading. While the amount of the mixed 60 of a graphite type carbonaceous materiel (a) (purity: 99.9% or materials Supplied in a unit time was controlled to a prede more, average particle size: 18 Jum, doo: 0.3356 nm, size of termined amount, the materials were Supplied in a biaxial the crystallite in the c axis direction (Lc): 100 nm, R value of kneading extruder and then kneaded. In this way, a paste the Raman spectrum: 0.18) and 30 parts by weight of a graph containing the positive electrode mixture was prepared. ite type carbonaceous material (b) (purity: 99.9% or more, Separately, the positive electrode active materials (A) and 65 average particle size: 21 um, doo: 0.3363 nm, size of the (B) were dissolved in aqua regia and the ratio of the elements crystallite in the c axis direction (Lc): 60 nm, R value of the contained in the materials (A) and (B) was measured by the Raman spectrum: 0.11) were mixed. Then, 98 parts by weight Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 71 of 90 PageID: 71 US 9,077,035 B2 23 24 of the graphite mixture, 1 part by weight of carboxymethyl trode lead member 8 connected to one end of the positive cellulose and 1 part by weight of a styrene-butadiene rubber electrode 1 and that of the negative electrode 2, respectively, were mixed in the presence of water to prepare a paste con are taken out from the electrode laminate 6 having the flat taining negative electrode mixture. This paste was uniformly spiral structure. The terminal 11 made of stainless steel is applied to both surfaces of a negative electrode current col attached to the cover plate 9 made of aluminum for closing the lector made of a strip-form copper foil having a thickness of opening of the battery case 4 with interposing the insulation 10 um, and then dried to form negative electrode mixture packing 10 made of polypropylene therebetween. The lead layers. The resultant sheet was pressed with a roller until the plate 13 made of stainless steel is attached to this terminal 11 density of the negative electrode mixture layers became 1.75 with interposing the insulator 12 therebetween. g/cm. The resultant sheet was then cutoutina predetermined 10 The cover plate 9 is inserted into the opening of the battery size. Thereafter, a lead member made of nickel was welded to case 4, and their joining portions are welded to each other, the cut piece to form a sheet-form negative electrode. thereby closing the opening of the battery case 4 to make the Preparation of Nonacqueous Electrolytic Solution interior of the battery airtight. In the battery shown in FIGS. 15 2A and 2B, the inlet 14 for pouring the electrolytic solution is An amount of LiPF was dissolved in a mixed solvent of made in the cover plate 9, and the inlet 14 is welded and sealed methylethyl carbonate, diethyl carbonate and ethylene car up by, for example, laser welding, with inserting a sealing bonate mixed at a volume ratio of 1.5:0.5:1 to attain a con member (not shown). In this way, the air-tightness of the centration of 1.2 mol/L. To this solution, 3% by weight of battery is kept. Accordingly, in the case of the battery shown fluorobenzene, 0.2% by weight of biphenyl, 0.5%; by weight in FIGS. 2A, 2B and 3, the electrolytic solution pouring inlet of propanesulfone, 10% by weight of CFOCH, and 3% by 14 is actually composed of the inlet 14 and the sealing mem weight of vinylene carbonate were added to prepare a non ber, but the inlet 14 is illustrated as such without a sealing aqueous electrolytic Solution. member in order to make the figure simple. The explosion proof vent 15 is made in the cover plate 9. Production of Nonaqueous Secondary Battery 25 In the battery 1 of Example 1, the positive electrode lead member 7 is directly welded to the cover plate 9, whereby the The positive electrode and the negative electrode were combination of the battery case 4 and the cover plate 9 func spirally wound with interposing, therebetween, a separator tions as a positive electrode terminal. The negative electrode made of a microporous polyethylene film (porosity: 53%, lead member 9 is welded to the lead plate 13, and the negative tensile strength in MD: 2.1 x 10 N/m, tensile strength in TD: 30 0.28x10 N/m, thickness: 16 um, gas permeability: 80 sec electrode lead member 8 and the terminal 11 are made elec onds/100-mL, thermal shrinkage factor after being kept at trically conductive through the lead plate 13, whereby the 105 CC for 8 hours: 3%, puncture strength: 3.5N (360 g)), to terminal 11 functions as a negative electrode terminal. How form an electrode body having a spiral structure. Thereafter, ever, the functions of the positive and negative electrodes may the electrode body was pressed to form a flat-shaped electrode 35 be reversed in accordance with the material of the battery case body and inserted into a box-shaped battery case made of an 4, etc. aluminum alloy. The positive and negative lead members FIG. 3 is a perspective view schematically illustrating the were welded and a cover plate was laser welded to the edge external appearance of the battery shown in FIGS. 2A and 2B. portion of an opening of the battery case. Then, the nonaque FIG.3 shows that the above-mentioned battery is a rectangu ous electrolytic Solution prepared in the above was poured 40 lar battery. Thus, FIG.3 schematically shows the battery, and into the battery case through an inlet made in the cover plate. depicts the specific elements out of the constituting elements The nonaqueous electrolytic Solution was Sufficiently infil of the battery. trated into the separator and the like. Thereafter, the battery was partially charged, and gas generated during the partial Example 2 charging was discharged. Then, the inlet was sealed up to 45 make the battery airtight. Thereafter, the battery was charged A nonaqueous secondary battery was fabricated in the and aged to yield a rectangular nonaqueous secondary battery same manner as in Example 1 except that fluorobenzene and having a structure as shown in FIGS. 2A and 2B and an CFOCH were not used. external appearance as shown in FIG. 3, and a width of 34.0 mm, a thickness of 4.0 mm, and a height of 50.0 mm. 50 Example 3 Here, the battery shown in FIGS. 2A, 2B and 3 will be explained. The positive electrode 1 and the negative electrode A nonaqueous secondary battery was fabricated in the 2 are spirally wound with interposing the separator 3 therebe same manner as in Example 1 except that propanesulfone was tween, as described above, and the spirally wound electrode not used. body is pressed in a flatform to form the electrode laminate 6 55 having a flat spiral structure. The laminate 6 together with a Example 4 nonaqueous electrolytic Solution is contained in the box shaped battery case 4. For simplicity, in FIG. 2, metal foils as A nonaqueous secondary battery was fabricated in the current collectors used to form the positive electrode 1 and the same manner as in Example 1 except that the positive elec negative electrode 2, and the electrolytic Solution are not 60 trode active material (A) was changed to depicted. LiCoooossMgoooosTio ooo-O2 (average particle size: 12 Lum), The battery case 4 is made of an aluminum alloy, and and the positive electrode active material (B) was changed to constitutes a main part of the exterior package of the battery. LiCooooo-Mgoloo Tioloo.2O2 (average particle size: 5 Lum). This battery case 4 also functions as a positive electrode The density of the positive electrode mixture layers (positive terminal. The insulator 5 made of a polytetrafluoroethylene 65 electrode) after pressing was 3.79 g/cm. With regard to the sheet is arranged on the inside bottom of the battery case 4. contents of the metal elements M, the molar contents of Mg The positive electrode lead member 7 and the negative elec and Ti in the positive electrode active material (B) were 3 Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 72 of 90 PageID: 72 US 9,077,035 B2 25 26 times larger and 3 times larger, respectively, than those in the 12 um) and the positive electrode active material (B) was positive electrode active material (A). changed to LiCoooo-Mgoloo.24Geoloo 12 Aloloo.24O2 (average particle size: 6 Lm). The density of the positive electrode Example 5 mixture layers (positive electrode) after pressing was 3.79 g/cm. With regard to the contents of the metal elements M, A nonaqueous secondary battery was fabricated in the the molar contents of Mg, Ge and Al in the positive electrode same manner as in Example 1 except that the weight ratio of active material (B) were 3 times larger, 3 times larger and 3 the positive electrode active material (A) to the positive elec times larger, respectively, than those in the positive electrode trode active material (B) was changed to 90:10. The density of active material (A). the positive electrode mixture layers (positive electrode) after 10 pressing was 3.75 g/cm. Example 10 Example 6 A nonaqueous secondary battery was fabricated in the same manner as in Example 1 except that the positive elec A nonaqueous secondary battery was fabricated in the 15 trode active material (A) was changed to same manner as in Example 1 except that a mixture of the LiCoosa-Nio.33Mno.33 Mgoloo.24Ti.o.o.o.12Alooo24O2 (average positive electrode active material (A) consisting of particle size: 5 Lm). The density of the positive electrode LiCoooosMgoooosTio-ooo-AloooosC2 (average particle size: mixture layers (positive electrode) after pressing was 3.72 12 um), and the positive electrode active material (B) consist g/cm. With regard to the contents of the metal elements M, ing of LiCoooo-Mgooo-Tioloo. 2Aloloo.4O2 (average particle the molar contents of Mg, Ti and Al in the positive electrode size: 5um) in a weight ratio of 50:50 was used as a positive active material (B) were 3 times larger, 3 times larger and 3 electrode active material. The density of the positive elec times larger, respectively, than those in the positive electrode trode mixture layers (positive electrode) after pressing was active material (A). 3.76 g/cm. With regard to the contents of the metal elements M, the molar contents of Mg, Ti and Al in the positive 25 Example 11 electrode active material (B) were 3 times larger, 3 times larger and 3 times larger, respectively, than those in the posi A nonaqueous secondary battery was fabricated in the tive electrode active material (A). same manner as in Example 1 except that this positive elec trode active material (A) was changed to Example 7 30 LiCoooossMgoooosTioooo-O2 (average particle size: 12 Lum), and the positive electrode active material (B) was changed to A nonaqueous secondary battery was fabricated in the LiCoooossMgoooosTio ooo-O2 (average particle size: 5 Lum). same manner as in Example 1 except that the positive elec The density of the positive electrode mixture layers (positive trode active material (A) was changed to electrode) after pressing was 3.79 g/cm. With regard to the LiCoooosMgoooosTio-ooo-SnoooosC2 (average particle size: 35 contents of the metal elements M, the molar contents of Mg 14 um) and the positive electrode active material (B) was and Ti were the same in the positive electrode active materials changed to LiCoooo-Mgoloo.24Ti.o.o.o.12Snooo-O2 (average (A) and (B). particle size: 6 Lm). The density of the positive electrode mixture layers (positive electrode) after pressing was 3.76 Example 12 g/cm. With regard to the contents of the metal elements M, 40 the molar contents of Mg, Ti and Sn in the positive electrode A nonaqueous secondary battery was fabricated in the active material (B) were 3 times larger, 3 times larger and 3 same manner as in Example 1 except that fluorobenzene was times larger, respectively, than those in the positive electrode not used. active material (A). 45 Example 13 Example 8 A nonaqueous secondary battery was fabricated in the A nonaqueous secondary battery was fabricated in the same manner as in Example 1 except that methylethylene same manner as in Example 1 except that the positive elec Sulfate was used in place of propanesulfone. trode active material (A) was changed to 50 LiCoooosMgoooos Zroooo-Alooooso2 (average particle size: Comparative Example 1 13 lum), and the positive electrode active material (B) was changed to LiCoooo.4Mgoloo.247nooo.2 Aloloo.24O2 (average A nonaqueous secondary battery was fabricated in the particle size: 6 Lm). The density of the positive electrode same manner as in Example 1 except that only mixture layers (positive electrode) after pressing was 3.8 55 LiCoooosMgoooosTio-ooo-AloooosC2 (average particle size: g/cm. With regard to the contents of the metal elements M, 12 um) was used as a positive electrode active material. The the molar contents of Mg, Zr and Al in the positive electrode density of the positive electrode mixture layers (positive elec active material (B) were 3 times larger, 3 times larger and 3 trode) after pressing was 3.7 g/cm. This is a comparative times larger, respectively, than those in the positive electrode example using only a positive electrode active material hav active material (A). 60 ing a large particle size, that is, the positive electrode active material (A), among the positive electrode active materials Example 9 used in Example 1. A nonaqueous secondary battery was fabricated in the Comparative Example 2 same manner as in Example 1 except that the positive elec 65 trode active material (A) was changed to A nonaqueous secondary battery was fabricated in the LiCoooosMgoooosGeoooo-AloooosC2 (average particle size: same manner as in Example 1 except that only Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 73 of 90 PageID: 73 US 9,077,035 B2 27 28 LiCoooo.4Mgo-oo:24Ti.o.o.o. 2Alooo24O2 (average particle size: 5 TABLE 1-continued um) was used as a positive electrode active material. The density of the positive electrode mixture layers (positive elec Discharge Capacity after trode) after pressing was 3.6 g/cm. This is a comparative Charge-Discharge Cycles example using only a positive electrode active material hav Example Charge voltage ing a small particle size, that is, the positive electrode active material (B), among the positive electrode active materials No. 4.2V 4.4W used in Example 1. 3 O2 137 4 O3 139 Comparative Example 3 10 5 O3 134 6 O3 135 7 O3 138 A nonaqueous secondary battery was fabricated in the 8 O3 136 same manner as in Example 1 except that the positive elec 9 O3 138 trode active material (A) was changed to LiCoO (average 10 O3 138 15 11 O2 122 particle size: 12 um), and the positive electrode active mate 12 O2 138 rial (B) was changed to LiCoO (average particle size: 5um). 13 O2 146 The density of the positive electrode mixture layers (positive C. 1 OO 1OO C. 2 99 104 electrode) after pressing was 3.8 g/cm. C. 3 O2 73 C. 4 OO 93 Comparative Example 4 C.5 O2 90 A nonaqueous secondary battery was fabricated in the same manner as in Comparative Example 1 except that The battery of Example 1 was disassembled after it was CFOCH was not used. This is a comparative example charged up to 4.4 V, and the surface of the positive electrode using only a positive electrode active material having a large 25 was analyzed by X-ray photoelectron spectroscopy (XPS). particle size, that is, the positive electrode active material (A) The contents of the fluorine atom and sulfur atom were 25 used in Example 1, and no fluorine-containing organic Sol atomic '% and 5 atomic '%, respectively. In the batteries of Vent. Examples 2 and 12, the content of the fluorine atom was 11 atomic '% and 20 atomic '%, respectively. Comparative Example 5 30 The content of the sulfur atoms on the surface of the posi tive electrode of the battery of Example 3 was less than the A nonaqueous secondary battery was fabricated in the detection limit, while it was 4% in the battery of Example 13. same manner as in Comparative Example 1 except that pro Herein, the XPS analysis of elements was carried out with panesulfone was not used. This is a comparative example PHI ESCA 5500MC (manufactured by ULVAC-PHI, Inc.) using only a positive electrode active material having a large 35 using the Al KC. ray at 400W. Then, an obtained curve was particle size, that is, the positive electrode active material (A) Subjected to peak separation, and an atomic percentage of used in Example 1, and no Sulfur-containing organic solvent. each atom is a ratio of the peak area for each atom to the total With the nonaqueous secondary batteries fabricated in peak area for all the atoms. Examples 1-13 and Comparative Examples 1-5, the follow Safety Evaluation ing properties were evaluated: 40 Each of the batteries fabricated in Examples and Compara Discharge Capacity after Charge-Discharge Cycles tive Examples was charged at a constant current of 0.2Cup to Each of the batteries fabricated in Examples and Compara 4.4 V, and then charged at a constant Voltage until the total tive Examples was charged at a constant current of 0.2Cup to charge time reached 8 hours. Subsequently, in a temperature a voltage of 4.2 V or 4.4 (corresponding to 4.3 V and 4.5V controlled bath, the battery was heated at a heating rate of 5° with reference to the potential of lithium), and then charged at 45 C./min. up to 150° C. and maintained at 150° C. for 10 a constant Voltage until the total charge time reached 8 hours. minutes. During this 10 minute period, the change of the Subsequently, the battery was discharged at a constant current surface temperature of the battery was monitored. The lower of 0.2 C down to a voltage of 3.3 V. Thereby, a discharge Surface temperature during heating means better safety at capacity of the battery was measured. Then, the above charge high temperature. The results are shown in Table 2. discharge cycle was repeated five times, and the discharge capacity after the fifth cycle was used to evaluate the dis 50 charge capacity after the charge-discharge cycles. The results TABLE 2 are shown in Table 1. In Table 1, the discharge capacity after the charge-discharge cycles obtained with each battery is Safety Evaluation shown as a relative value in relation to the discharge capacity Example Charge Voltage of the battery of Comparative Example 1 after the charge 55 No. 4.4W discharge cycles, which is “100'. 155 158 TABLE 1. 1S6 160 155 Discharge Capacity after 60 Charge-Discharge Cycles 162 159 Example Charge voltage 1S6 1S6 No. 4.2V 4.4W 1 154 167 1 103 140 65 157 102 137 s 1S6 Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 74 of 90 PageID: 74 US 9,077,035 B2 29 30 TABLE 2-continued the lithium-containing transition metal oxides is from 5% by weight to 60% by weight, Safety Evaluation wherein the content of said lithium-containing transition metal oxidehaving the largest average particle size in the Example Charge voltage lithium-containing transition metal oxides is from 40% No. 4.4W by weight to 95% by weight, and C. 1 >170 wherein an amount of said fluorine-containing organic Sol C. 2 168 C. 3 >170 vent is 0.1% by weight to 30% by weight based on the C. 4 >170 whole weight of the electrolyte. C.5 >170 10 2. The nonaqueous secondary battery according to claim 1, wherein the lithium-containing transition metal oxide having the largest average particle size is a lithium-containing tran As can be seen from the results in Tables 1 and 2, the nonaqueous secondary batteries of Examples 1-13 according sition metal oxide represented by the formula (2) wherein c to the present invention had larger discharge capacities and and d satisfy the following equation, respectively: 15 0.0002sc.<0.005 and OsdkO.005. better charge-discharge cycle characteristics than those of 3. The nonaqueous secondary battery according to claim 2, Comparative Examples 1-5, and further, they suffered from wherein Zin the formula (1) is larger than c in the formula (2). less temperature rising in the full-charged or overcharged 4. The nonaqueous secondary battery according to claim 1, state, and had excellent safety. wherein Zin the formula (1) is larger than c in the formula (2). The invention claimed is: 5. The nonaqueous secondary battery according to claim 1, 1. A nonaqueous secondary battery comprising: wherein, in the formula (1), the metal elements Mare Mgand a positive electrode having a positive electrode mixture at least one metal element selected from the group consisting layer, a negative electrode, and a nonaqueous electro lyte, of Ti, Zr, Ge, Nb, Al and Sn; a content of Mg is from 0.1% by wherein the positive electrode comprises, as active mate mole to less than 2% by mole based on the amount of the 25 transition metal M'; when Ti, Zr, Ge or Nb is contained, a rials, at least two lithium-containing transition metal total content thereof is from 0.05% by mole to less than 0.5% oxides having different average particle sizes, and the by mole based on the amount of the transition metal M'; and lithium-containing transition metal oxide having the when Al or Sn is contained, a total content thereof is from Smallest average particle size is a lithium-containing 0.1% by mole to less than 1% by mole based on the amount of transition metal oxide represented by the formula (1): 30 the transition metal M'. Li, M.M.M.O. (1) 6. The nonaqueous secondary battery according to claim 1, wherein M' represents at least one transition metal element wherein, in the formula (2), the metal elements Mare Mgand selected from Co, Ni and Mn, M represents Mg and at at least one metal element selected from the group consisting least one metal element selected from the group consist of Ti, Zr, Ge, Nb, Aland Sn; a content of Mg is from 0.01% by ing of Ti, Zr, Ge, Nb, Al and Sn, M represents at least 35 mole to less than 0.5% by mole based on the amount of the one element selected from the group consisting of Na, K, transition metal M'; when Ti, Zr, Ge or Nb is contained, a Rb, Be, Ca, Sr., Ba, Sc, Y, La, Hf, V, Ta, Cr, Mo, W., Tc, total content thereofis from 0.005% by mole to less than 0.3% Re, Fe, Ru, Rh, Cu, Ag, Au, B, Ca, In, Si, P and Bi, and by mole based on the amount of the transition metal M'; and X, y, Zand V are numbers satisfying the equations respec when Al or Sn is contained, a total content thereof is from tively: 0.97sx<1.02, 0.8sy<1.02, 0.002 Exhibit 4 Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 76 of 90 PageID: 76 USOO9166251B2 (12) United States Patent (10) Patent No.: US 9,166,251 B2 Katayama et al. (45) Date of Patent: Oct. 20, 2015 (54) BATTERY SEPARATOR AND NONAQUEOUS (58) Field of Classification Search ELECTROLYTE BATTERY CPC ... H01M 2/1686; H01M 2/1673; H01M 2/14 USPC ...... 429/144, 145 (75) Inventors: Hideaki Katayama, Ibaraki (JP); See application file for complete search history. Mitsuhiro Kishimi, Ibaraki (JP); Yoshinori Sato, Ibaraki (JP); Yasutaka Kuroki, Ibaraki (JP); Toshiyuki (56) References Cited Edamoto, Ibaraki (JP) U.S. PATENT DOCUMENTS (73) Assignee: HITACHI MAXELL, LTD., Ibaraki-Shi 6,447,958 B1 9, 2002 Shinohara et al. (JP) 2001/0005560 A1 6/2001 Yoshida et al. (*) Notice: Subject to any disclaimer, the term of this (Continued) patent is extended or adjusted under 35 U.S.C. 154(b) by 846 days. FOREIGN PATENT DOCUMENTS (21) Appl. No.: 12/673,961 CN 101019266 A 8, 2007 EP 1 115166 A1 T 2001 (22) PCT Fled: Sep. 30, 2008 (Continued) (86). PCT No.: PCT/UP2008/0677S7 Primary Examiner — Stewart Fraser S371 (c)(1), Assistant Examiner — Olatunji Godo (2), (4) Date: Feb. 17, 2010 (74) Attorney, Agent, or Firm — Birch, Stewart, Kolasch & (87) PCT Pub. No.: WO2009/044741 Birch, LLP PCT Pub. Date: Apr. 9, 2009 (57) ABSTRACT (65) Prior Publication Data A nonaqueous electrolyte battery of the present invention US 2011 FOO52987 A1 Mar. 3, 2011 includes a positive electrode having a positive active material capable of intercalating and deintercalating a lithium ion, a (30) Foreign Application Priority Data negative electrode having a negative active material capable of intercalating and deintercalating a lithium ion, a separator Oct. 3, 2007 (JP) ...... 2007-2595.75 interposed between the positive electrode and the negative Feb. 21, 2008 (JP) ...... 2008-0395.27 electrode, and a nonaqueous electrolyte. The heat generation starting temperature of the positive electrode is 180° C. or (51) Int. Cl. higher. The separator includes heat-resistant fine particles and HOLM 2/14 (2006.01) a thermoplastic resin. The proportion of particles with a par HIM I/0525 (2010.01) ticle size of 0.2 um or less in the heat-resistant fine particles is (Continued) 10 vol% or less and the proportion of particles with a particle size of 2 um or more in the heat-resistant fine particles is 10 (52) U.S. Cl. vol% or less. The separator effects a shutdown in the range of CPC ...... H0IM 10/0525 (2013.01); H0IM 2/166 100° C. to 150° C. (2013.01); H0 IM 2/1646 (2013.01); HOLM 2/1653 (2013.01); H0IM 10/4235 (2013.01); Y02E 60/122 (2013.01) 37 Claims, 2 Drawing Sheets 15 g 10 14 20 Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 77 of 90 PageID: 77 US 9,166,251 B2 Page 2 (51) Int. Cl. JP 2004-303474. A 10, 2004 HOLM 2/6 (2006.01) JP 2006-139978 A 6, 2006 JP 2006-269359 A 10, 2006 HIM I/42 (2006.01) JP 2006-351386 A 12/2006 JP 2007-157723. A 6, 2007 (56) References Cited JP 2007-273.123. A 10/2007 JP 2007-273443 A 10/2007 U.S. PATENT DOCUMENTS JP 2007-280911. A 10/2007 2004/019 1611 A1 9, 2004 Imachi et al. JP 2007-335294. A 12/2007 2006/0141352 A1* 6/2006 Kato et al...... 429/144 JP 2008-27634. A 2, 2008 2007/0231700 A1 10, 2007 Watanabe JP 2008-123996 A 5, 2008 2007/0264577 A1 1 1/2007 Katayama et al. JP 2008-210541. A 9, 2008 2008/00386.31 A1 2/2008 Nakura et al. KR 10-2007-0083,975 A 8, 2007 2010/022 1965 A1 9/2010 Katayama et al. WO WO-00/79618 A1 12/2000 WO WO 2006/062153 A1 6, 2006 FOREIGN PATENT DOCUMENTS WO WO-2007/066768 A1 6, 2007 WO WO 2009,096451 A1 8/2009 JP 2000-30686 A 1, 2000 JP 2004-296325 A 10, 2004 * cited by examiner Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 78 of 90 PageID: 78 Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 79 of 90 PageID: 79 U.S. Patent Oct. 20, 2015 Sheet 2 of 2 US 9,166,251 B2 15 9 11 10 14 - 20 NuN1 FG.2 Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 80 of 90 PageID: 80 US 9, 166,251 B2 1. 2 BATTERY SEPARATOR AND NONAQUEOUS occur due to thermal shrinkage of the separator in the width ELECTROLYTE BATTERY direction. Thus, it is necessary to suppress the thermal shrink age in the width direction. CROSS REFERENCE TO RELATED Patent Document 1: JP 2004-296325 A APPLICATIONS Patent Document 2: JP 2004-303474. A Patent Document 3: JP 2006-351386 A This application is a National Phase application of PCT/ Patent Document 4: WO 2007/66768 JP2008/067757 filed on Sep. 30, 2008, which claims the Patent Document 5:JP 2007-27.3123 A benefit under 35 U.S.C. S 119(a) to Japanese Patent Applica Patent Document 6: JP 2007-273443 A tion Nos. 2007-259575 (filed on Oct. 3, 2007), and 2008 10 Patent Document 7:JP 2007-280911 A 039527 (filed on Feb. 21, 2008). The entire contents of all of the above applications are hereby incorporated by reference. DISCLOSURE OF INVENTION TECHNICAL FIELD Therefore, with the foregoing in mind, it is an object of the 15 present invention to provide a battery separator that can con The present invention relates to a nonaqueous electrolyte stitute a nonaqueous electrolyte battery having excellent battery that is safe from being allowed to stand at high tem safety in a high-temperature environment, and a nonaqueous peratures. electrolyte battery using the battery separator. BACKGROUND ART A battery separator of the present invention includes heat resistant fine particles and a thermoplastic resin. The propor A nonaqueous electrolyte battery Such as a lithium ion tion of particles with a particle size of 0.2 um or less in the battery is characterized by a high energy density and thus has heat-resistant fine particles is 10 vol% or less and the pro been widely used as a power source for portable equipment portion of particles with a particle size of 2 um or more in the Such as a portable telephone and a notebook personal com 25 heat-resistant fine particles is 10 vol% or less. A shutdown is puter. In recent years, the capacity of the nonaqueous elec effected in the range of 100° C. to 150° C. trolyte battery is likely to increase further as the performance A nonaqueous electrolyte battery of the present invention of the portable equipment becomes higher. In parallel with includes the following: a positive electrode having a positive this, it is also important to ensure safety. active material capable of intercalating and deintercalating a In the current nonaqueous electrolyte battery, e.g., a poly 30 lithium ion; a negative electrode having a negative active olefin microporous film with a thickness of about 20 to 30 um material capable of intercalating and deintercalating a lithium is used as a separator that is interposed between a positive ion; a separator interposed between the positive electrode and electrode and a negative electrode. However, the commonly the negative electrode; and a nonaqueous electrolyte. A heat used separator easily shrinks when the temperature in the generation starting temperature of the positive electrode is battery becomes extremely high, and can causea short circuit. 35 Therefore, as a means of improving the safety of the nonaque 180° C. or higher. The separator includes heat-resistant fine ous electrolyte battery, the heat resistance of the separator particles and a thermoplastic resin. The proportion of par may be improved. ticles with a particle size of 0.2 um or less in the heat-resistant On the other hand, e.g., when the nonaqueous electrolyte fine particles is 10 vol% or less and the proportion of particles battery in a charged State is placed in a high-temperature 40 with a particle size of 2 um or more in the heat-resistant fine environment, heat can be generated from the positive elec particles is 10 vol% or less. The separator effects a shutdown trode to raise the temperature in the battery further. Therefore, in the range of 100° C. to 150° C. as a means of improving the safety of the nonaqueous elec In the nonaqueous electrolyte battery of the present inven trolyte battery, a positive active material having high thermal tion, the heat generation starting temperature of the positive stability also may be used. 45 electrode is as high as 180° C. or higher. This can suppress For example, Patent Documents 1 and 2 propose a non heat to be generated from the positive electrode when the aqueous electrolyte battery that uses a positive active material battery is placed in a high-temperature environment. More having high thermal stability along with a separator having over, the nonaqueous electrolyte battery uses the battery sepa good heat resistance. However, in the technology as disclosed rator that includes a thermoplastic resin and heat-resistant in Patent Document 1, there is a limit to the reduction in 50 fine particles containing particles with a particle size of 0.2 thickness of the separator because a nonwoven fabric or paper um or less in a proportion of 10 vol% or less and particles is used for the separator. For example, if the separator has a with a particle size of 2 um or more in a proportion of 10 vol thickness of 30 um or less and an active material Such as % or less, and that effects a shutdown in the range of 100° C. graphite is used for the negative electrode, a short circuit may to 150° C. This can reliably prevent a short circuit due to be likely to occur. Moreover, the technology as disclosed in 55 contact between the positive electrode and the negative elec Patent Document 2 focuses only on thermal shrinkage of the trode at high temperatures. As a result of these effects, it is separator at 120°C. Thus, it is difficult to ensure the safety of possible to provide a nonaqueous electrolyte battery having the battery at temperatures higher than this. excellent safety in a high-temperature environment. Patent Documents 3 to 7 propose a multilayer separator that includes a high heat-resistant layer as a technology for 60 BRIEF DESCRIPTION OF DRAWINGS preventing a short circuit due to thermal shrinkage of the separator. However, the separator needs to be further FIG. 1A is a schematic plan view of a nonaqueous electro improved to achieve the safety of the battery at even higher lyte battery of the present invention. FIG. 1B is a schematic temperatures. cross-sectional view of a nonaqueous electrolyte battery of For example, in the case of an electrode body obtained by 65 the present invention. winding the positive electrode and the negative electrode with FIG. 2 is schematic diagram showing the appearance of a the separator interposed between them, a short circuit can nonaqueous electrolyte battery of the present invention. Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 81 of 90 PageID: 81 US 9, 166,251 B2 3 4 BEST MODE FOR CARRYING OUT THE starting temperature of the positive electrode is below 180°C. INVENTION The particle size of the positive active material is preferably 0.01 to 30 um. The heat generation starting temperature of the positive The conductive assistant of the positive electrode may be a electrode of the nonaqueous electrolyte battery of the present carbon material such as carbon black. The binder of the posi invention is 180° C. or higher, and preferably 200° C. or tive electrode may be a fluorocarbon resin such as polyvi higher. nylidene fluoride (PVDF). In the present specification, the heat generation starting The current collector of the positive electrode may be, e.g., temperature of the positive electrode is determined as fol a foil, a punched metal, a mesh, or an expanded metal, which 10 are made of aluminum or the like. In general, an aluminum lows. First, a DSC curve is obtained by measuring the positive foil with a thickness of 10 to 30 um can be suitably used. electrode in a charged State with a differential scanning calo A lead portion of the positive electrode is generally pro rimeter (DSC) from 30° C. at a rate oftemperature rise of 10° vided in the following manner. A part of the current collector C./min in the presence of a nonaqueous electrolyte used for remains exposed without forming the positive electrode mix the battery (as will be described later). In this DSC curve, the 15 ture layer when the positive electrode is produced, and this heat generation starting temperature indicates a temperature exposed portion can serve as the lead portion. However, the at an intersection point of two lines: one is an extension line of lead portion does not necessarily need to be integrated with the base line on the high temperature side; and the other is a the current collector from the beginning and may be provided tangent to the curve of the exothermic peak on the low tem by connecting an aluminum foil or the like to the current perature side at a point where the curve has the maximum collector afterward. slope. The “charged state' of the positive electrode indicates The composition of the positive electrode mixture layer of a full-charge state according to the battery design. Specifi the positive electrode is preferably 80 to 98 mass % of the cally, assuming that the rated charging Voltage of the battery positive active material, 1 to 18 mass % of the conductive is V, a constant-current and constant-voltage charge is assistant, and 1 to 10 mass % of the binder. The thickness of performed in Such a manner that the battery is charged at a 25 the positive electrode mixture layer (per one side of the cur constant current until the battery Voltage reaches the V, rent collector) is preferably 20 to 100 um. and Subsequently charged at a constant Voltage of V. The To suppress thermal shrinkage and provide a shutdown battery is considered in the full-charge state when the current property, it is preferable that the separator of the nonaqueous value during the constant-Voltage charge is reduced to /10 of electrolyte battery of the present invention has a multilayer a current value (1 C) based on the rated capacity of the battery. 30 structure. Specifically, the multilayer structure includes a The positive electrode of the present invention includes a heat-resistant layer for Suppressing the thermal shrinkage and current collector and a positive electrode mixture layer isolating the positive electrode from the negative electrode at formed on one side or both sides of the current collector. The high temperatures and a shutdown layer for ensuring the positive electrode mixture layer is composed of a positive shutdown property. electrode mixture that is obtained by mixing a positive active 35 In the present specification, a shutdown is effected in Such material, a conductive assistant, a binder, etc. a manner that the resin constituting the separator is melted at To set the heat generation starting temperature of the posi a temperature not more than the thermal runaway (abnormal tive electrode at 180° C. or higher, it is preferable to use the heat generation) temperature of the battery and the pores of positive active material having good thermal stability and a the separator are filled with the molten resin, thereby increas high heat generation starting temperature. Specifically, it is 40 ing the internal resistance of the battery to interrupt the cur preferable to use at least one compound selected from the rent. following: a spinel-type lithium-containing complex oxide A temperature at which the separator effects a shutdown expressed as a general formula Li,Mn2-M',O4 (where (i.e., a shutdown temperature) is preferably 100° C. or higher, M' is at least one element selected from the group consisting since if the shutdown temperature is too low, a shutdown is of Fe, Ni, Mg., Zn, Co, Cr,Al, B.V. Si, Sn, Nb, Ta, Cu, Mo, Ti, 45 effected during the normal operation of the battery, and thus and W. -0.1sts0.1, and 0 US 9, 166,251 B2 5 6 braneata pressure of 0.879 g/mm is at least tentimes as large more in the heat-resistant fine particles not more than 10 vol as the Gurley value at room temperature before heating. %, respectively, the particle size of the material particles may The heat-resistant layer of the separator is preferably a be controlled in the range of 0.2 to 2 um. If the particle size of porous layer including heat-resistant fine particles and a the material particles is too large, the material particles can be binder as components. In the present specification, the "heat 5 pulverized with a grinder Such as a ball mill, a sand mill, a jet resistant fine particles' are fine particles with a heat-resistant mill, or a cyclone mill to reduce the particle size. If the particle temperature of 200° C. or higher, and the “heat-resistant size of the material particles is too small, the particles size can temperature' is a temperature at which a Substantial physical be increased with a granulator Such as mechanofusion or a change Such as a thermal deformation does not occur. spray drier. Moreover, the particles with a particle size of 0.2 The heat-resistant fine particles are not particularly limited 10 um or less and the particles with a particle size of 2 um or as long as they are electrochemically stable and have electri more may be filtered out with various types of classifiers such cal insulation, but are preferably inorganic fine particles. Spe as a sieve, a classification cyclone, and a filter, so that the cific examples of the inorganic fine particles include the fol remaining particles are used. lowing: fine particles of inorganic oxides such as an iron The thermal shrinkage ratio of the separator of the present oxide, silica (SiO2), alumina (Al2O), TiO, and BaTiO, fine 15 invention is preferably 10% or less, and more preferably 5% particles of inorganic nitrides such as an aluminum nitride or less at the temperature T. Specifically, the thermal shrink and a silicon nitride; fine particles of hardly-soluble ionic age ratio of the separator in the width direction is preferably crystals such as a calcium fluoride, a barium fluoride, and a 10% or less at 200° C. By controlling the particle size of the barium sulfate; and fine particles of covalent crystals such as heat-resistant fine particles, the separator with Such a small silicon and diamond. The inorganic oxide fine particles may thermal shrinkage ratio can be achieved even if the separator be fine particles of materials derived from the mineral has a structure in which the heat-resistant layer is integrated resources such as boehmite, Zeolite, apatite, kaoline, mullite, with the shutdown layer. Thus, it is possible to sufficiently spinel, olivine, and mica or artificial products of these mate Suppress the occurrence of a short circuit due to shrinkage of rials. Moreover, the inorganic fine particles may be electri the separator when the temperature in the battery becomes cally insulating particles obtained by covering the Surface of 25 high. The thermal shrinkage ratio is preferably as Small as a conductive material with a material having electrical insu possible, and particularly preferably 0%. lation (e.g., any of the above inorganic oxides). Examples of When the separator has a structure in which the heat the conductive material include conductive oxides Such as a resistant layer and the shutdown layer are not integrated, but metal, SnO, and an indium tin oxide (ITO) and carbonaceous separated from each other, the thermal shrinkage ratio of the materials such as carbon black and graphite. 30 heat-resistant layer is preferably 10% or less, and more pref Organic fine particles also can be used as the heat-resistant erably 5% or less at the temperature T. Specifically, the ther fine particles. Specific examples of the organic fine particles mal shrinkage ratio of the heat-resistant layer in the width include the following: fine particles of cross-linked polymers direction is preferably 10% or less at 200°C. In this case, the Such as polyimide, a melamine resin, a phenol resin, cross above thermal shrinkage ratio also can be ensured by control linked polymethyl methacrylate (cross-linked PMMA), 35 ling the particle size of the heat-resistant fine particles. Thus, cross-linked polystyrene (cross-linked PS), polydivinylben it is possible to sufficiently Suppress the occurrence of a short Zene (PDVB), and a benzoguanamine-formaldehyde conden circuit due to shrinkage of the shutdown layer when the sation product; and fine particles of heat-resistant polymers temperature in the battery becomes high. Needless to say, the Such as thermoplastic polyimide. The organic resin constitut thermal shrinkage ratio is preferably as Small as possible, and ing these organic fine particles may be a mixture, a modified 40 particularly preferably 0%. product, a derivative, a copolymer (a random copolymer, an By ensuring the above thermal shrinkage ratio, the separa alternating copolymer, a block copolymer, or a graft copoly tor can be maintained to have a width larger than, e.g., the mer), or a cross-linked product (in the case of the heat-resis width of the negative electrode at the temperature T when tant polymer) of the above polymeric materials. actually incorporated into the battery. Therefore, the occur The above examples of the heat-resistant fine particles may 45 rence of a short circuit can be sufficiently suppressed. be used individually or in combination of two or more. The average particle size of the heat-resistant fine particles Among the above heat-resistant fine particles, the inorganic is in the range of preferably 0.3 um, more preferably 0.4 um, oxide fine particles are more Suitable, and alumina, silica, and most preferably 0.5um to preferably 1.5um, more preferably boehmite are even more suitable. This is because these mate 1.2 um, most preferably lum. The average particle size of the rials have a high heat-resistant temperature as well as high 50 heat-resistant fine particles can be defined as a number aver electrochemical stability. age particle size that is measured with a laser diffraction The heat-resistant fine particles contain particles with a particle size analyzer (e.g., LA-920 manufactured by Horiba, particle size of 0.2 um or less in a proportion of 10 vol% or Ltd.) by dispersing the heat-resistant fine particles in a less and particles with a particle size of 2 um or more in a medium, in which the particles are insoluble. proportion of 10 vol% or less, and also have a narrow particle 55 The heat-resistant fine particles can have any shape Such as size distribution and a uniform particle size. This configura a sphere (true sphere or Substantial sphere), a rugby ball, a tion can Suppress thermal shrinkage of the separator at a polyhedron, or a plate-like particle. However, it is more pref temperature T (C.) that is close to, e.g., 10° C. lower than the erable that the heat-resistant fine particles are in the form of heat generation starting temperature of the positive electrode plate-like particles. The use of plate-like particles as the heat (in this case, the upper limit of T is 200° C., and T does not 60 resistant fine particles makes it easier to form a heat-resistant exceed 200° C. even if the heat generation starting tempera layer that is less susceptible to thermal shrinkage. Therefore, ture of the positive electrode is higher than 210°C.). Thus, it even if the separator has a structure in which the heat-resistant is possible to prevent the electrode body from being short layer is integrated with the shutdown layer that is a porous circuited due to the thermal shrinkage of the separator in the film made of a thermoplastic resin, thermal shrinkage of the width direction. 65 whole separator caused by thermal shrinkage of the shutdown To make the proportions of particles with a particle size of layer can be effectively suppressed. For example, the thermal 0.2 Lum or less and particles with a particle size of 2 um or shrinkage ratio of the separator can be 5% or less at 165°C., Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 83 of 90 PageID: 83 US 9, 166,251 B2 7 8 which is measured by a method as will be described later. modified product of the cellulose such as carboxymethyl Although the reason the thermal shrinkage of the separator or cellulose; polypropylene (PP); polyesters such as polyethyl the heat-resistant layer is easily suppressed by using the heat ene terephthalate (PET), polyethylene naphthalate (PEN), resistant fine particles in the form of plate-like particles is not and polybutylene terephthalate (PBT); resins such as poly clear, it is considered that the plane surfaces of the individual acrylonitrile (PAN), aramid, amide-imide, and polyimide: particles are likely to be oriented in the direction parallel to and inorganic materials (inorganic oxides) such as glass, alu the plane direction of the separator, and the particles are more mina, and silica. The porous base material may include either closely packed because of such orientation, thereby resisting one type or more than one type of these constituents. The the shrinkage. porous base material also may include various types of addi In the present specification, the thermal shrinkage ratios of 10 tives (e.g., an antioxidant when the resin is used) as needed in the separator and the heat-resistant layer are determined in the addition to the above constituents. following manner. The separator or the heat-resistant layer is The content of the heat-resistant fine particles in the heat cut into 3 cmx3 cm, and then interposed between two glass resistant layer is preferably 20 vol% or more, more preferably plates, each of which has a thickness of 5 mm. This sample is 50 vol% or more, and further preferably 80 vol% or more of allowed to stand in a thermostatic bath at a predetermined 15 the total volume of components in the heat-resistant layer. By temperature for 1 hour and heated. Subsequently, dimen increasing the content of the heat-resistant fine particles in the sional changes of the sample are measured. That is, the ther heat-resistant layer, thermal shrinkage of the heat-resistant mal shrinkage ratio is defined as a ratio of decrease in the layer or the whole separator can be favorably Suppressed. As width of the separator after heating to that of the separator at described above, the heat-resistant layer preferably includes a room temperature before heating. When the thermal shrink binder. In view of this, the preferred upper limit of the content age ratio involves directivity, it is defined as a ratio of decrease of the heat-resistant fine particles in the heat-resistant layeris, in the width of the separator in the direction in which the e.g., 99 vol% of the total volume of components in the separator shrinks the most. heat-resistant layer. If the content of the heat-resistant fine In the present invention, it is preferable that the heat-resis particles in the heat-resistant layer is too small, e.g., the tant layer includes a binderto integrate the heat-resistant layer 25 content of the binder in the heat-resistant layer should be with the shutdown layer or the electrode, or to bind the heat increased. In Such a case, however, the pores of the heat resistant fine particles constituting the heat-resistant layer. resistant layer are filled with the binder, which may impair, Examples of the binder include the following: an ethylene e.g., the function of the separator. On the other hand, if a vinyl acetate copolymer (EVA having 20 to 35 mol % of a hole-opening agent or the like is used to provide a porous structural unit derived from vinyl acetate); an ethylene 30 heat-resistant layer, the space between the heat-resistant fine acrylic acid copolymer Such as an ethylene-ethyl acrylate particles becomes extremely large, so that the effect of Sup copolymer (EEA); fluoro-rubber; styrene-butadiene rubber pressing thermal shrinkage may be reduced. (SBR); carboxymethyl cellulose (CMC); hydroxyethyl cel The content of the binder in the heat-resistant layer is lulose (HEC); polyvinyl alcohol (PVA); polyvinyl butyral preferably 1 to 20 vol% of the total volume of components in (PVB); polyvinyl pyrrolidone (PVP); poly-N-vinylaceta 35 the heat-resistant layer. mide; a cross-linked acrylic resin; polyurethane; and an When the heat-resistant layer includes the porous base epoxy resin. The above examples of the binder may be used material composed of the heat-resistant resin or the heat individually or in combinations of two or more. resistant fibers, the content of the heat-resistant resin or the Among the above binders, the heat-resistant resins having heat-resistant fibers of the porous base material in the heat heat resistance at 150° C. or higher are suitable. In particular, 40 resistant layer is in the range of preferably 10 vol%, more highly flexible materials such as the ethylene-acrylic acid preferably 30 vol% to preferably 90 vol%, more preferably copolymer, the fluoro-rubber, and the SBR are more suitable. 70 vol% of the total volume of components in the heat Specific examples of the highly flexible materials include the resistant layer. following: EVA, "EVAFLEX series (trade mane) manufac The material of the shutdown layer of the separator is not tured by DU PONT-MITSUI POLYCHEMICALS CO., 45 particularly limited as long as it is a thermoplastic resin that is LTD.; EVA manufactured by NIPPON UNICAR CO.,LTD.; electrochemically stable, also stable to the nonaqueous elec an ethylene-acrylic acid copolymer, “EVAFLEX-EEA series trolyte of the battery, and preferably able to ensure the shut (trade name)' manufactured by DUPONT-MITSUI POLY down temperature. In particular, polyolefin (polyethylene, CHEMICALS CO., LTD.; EEA manufactured by NIPPON polypropylene, an ethylene-propylene copolymer, etc.) hav UNICAR CO.,LTD., fluoro-rubber, “DAI-ELLATEX series 50 ing a softening point (melting point, glass transition point, (trade name)' manufactured by DAIKIN INDUSTRIES, etc.) of 100 to 150° C. is suitable. Moreover, polyester also Ltd.; SBR, “TRD-2001 (trade name)' manufactured by JSR can be used. Corporation; and SBR, “EM-400B (trade name)' manufac The shutdown layer may be in any form as long as it has tured by ZEON CORPORATION. Moreover, the cross Sufficientionic conductance to obtain necessary battery char linked acrylic resin (self-cross-linking acrylic resin) that has 55 acteristics. As the shutdown layer, porous films can be used, a low glass transition temperature is also suitable, and including a porous film that is formed by aggregating fine includes butyl acrylate as the main component and has cross particles and an ion-permeable porous film (microporous linking of the butyl acrylate. film) that has many pores and is formed by a conventional When the binder is used, it may be dissolved or emulsified Solvent extraction method, a dry or wet drawing method, or in a medium (solvent) of a composition (slurry etc.) for form 60 the like. More specifically, a polyethylene porous film, a ing the heat-resistant layer, as will be described later. polypropylene porous film, a polyester porous film, etc. are The heat-resistant layer may further include a porous base suitable for the shutdown layer. material as long as the heat resistance is not impaired. The When the shutdown layer is formed, e.g., by aggregating porous base material may be, e.g., a porous film made of a thermoplastic resin fine particles, the shutdown layer may heat-resistant resin, or a woven or nonwoven fabric made of 65 include a binder as needed to bind the fine particles or to heat-resistant fibers. Examples of the constituents of the integrate the shutdown later with the heat-resistant layer or porous base material includes the following: cellulose and a the electrode. The various types of binders that may be Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 84 of 90 PageID: 84 US 9, 166,251 B2 10 included in the heat-resistant layer also can be used for the Moreover, if the heat-resistant layer is toothin, the function of shutdown layer. These binders may be used individually or in isolating the positive electrode from the negative electrode at combinations of two or more. Like the heat-resistant layer, high temperatures may be reduced, and also the effect of when the binder is used, it may be dissolved or emulsified in Suppressing thermal shrinkage of the whole separator may be a medium (solvent) of a composition (slurry etc.) for forming reduced when the separator has a structure in which the heat the shutdown layer, as will be described later. resistant layer is integrated with the shutdown layer. If the When the shutdown layer includes the binder, it is prefer heat-resistant layer is too thick, the thickness of the whole able that the content of the thermoplastic resin fine particles is separator is increased. 70 to 99 vol% of the total volume of components in the The average pore diameter of the separator is in the range shutdown layer, and the content of the binder is 1 to 30 vol% 10 of preferably 0.01 um, more preferably 0.05um to preferably of the total volume of components in the shutdown layer. 1 um, more preferably 0.5um. The average pore diameter of Although the separator can have one heat-resistant layer the shutdown layer is preferably 0.01 to 5 um. The average and one shutdown layer, it may have a plurality of heat pore diameter of the heat-resistant layer is preferably 0.05 to resistant layers that are disposed, e.g., on both sides of the 1 um. In the case of the battery that includes a wound elec shutdown layer or a plurality of shutdown layers. However, 15 trode body obtained by winding the positive electrode and the the thickness of the separator increases with the number of negative electrode via the separator in a spiral fashion, the layers, which may lead to an increase in the internal resistance separator is bent while the electrode body is wound, and thus or a reduction in the energy density. Therefore, the separator can cause a crack or the like in the heat-resistant layer. How should not include too many layers, and the total number of ever, when the separator has the above average pore diameter layers (the heat-resistant layer and the shutdown layer) con (particularly, the shutdown layer has the above average pore stituting the separator is preferably five layers or less, and diameter), even if the heat-resistant layer has a crack or the more preferably two layers. like, it is possible to prevent lithium dendrites from passing When the separator has a multilayer structure of the heat through the crack of the heat-resistant layer. In the case of the resistant layer and the shutdown layer, the heat-resistant layer battery that includes a so-called laminated electrode body may be integrated with the shutdown layer. Alternatively, the 25 obtained by laminating the positive electrode, the negative heat-resistant layer and the shutdown layer are not integrated, electrode, and the separator, instead of the wound electrode but may be provided as independent films, or the heat-resis body, the average pore diameters of the separator, the shut tant layer or the shutdown layer may be individually inte down layer, and the heat-resistant layer do not have to meet grated with the electrode. When the heat-resistant layer and the above suitable values, but more preferably fall in the the shutdown layer are not integrated, the separator may be 30 respective ranges. configured by laminating the heat-resistant layer and the shut In terms of improving the ion permeability by ensuring the down layer together in the nonaqueous electrolyte battery. retention of the nonaqueous electrolyte, the porosity of the In terms of isolating the positive electrode from the nega whole separator is preferably 30% or more in a dry state. On tive electrode more reliably, the thickness of the separator is the other hand, in terms of ensuring the strength of the sepa preferably 6 um or more, and more preferably 10um or more. 35 rator and preventing an internal short circuit, the porosity of On the other hand, if the separator is too thick, the energy the whole separator is preferably 70% or less in a dry state. density of the battery may be reduced. Therefore, the thick The porosity P(%) of the separator can be calculated from the ness of the separator is preferably 50 um or less, and more thickness of the separator, the mass per unit area of the sepa preferably 30 um or less. rator, and the densities of the components of the separator by When the thicknesses of the shutdown layer and the heat 40 obtaining a Summation for each component i with the follow resistant layer of the separator are represented by A (um) and ing formula (1). B (um), respectively, the ratio A/B of A to B is in the range of preferably 4, more preferably /2 to preferably 5, more pref erably 4. As described above, in the separator of the present where a, represents the ratio of a component i expressed as invention, even if the thickness ratio is increased by reducing 45 a mass percentage, p, represents the density (g/cm) of the the thickness of the heat-resistant layer, the occurrence of a component i, m represents the mass (g/cm) per unit area of short circuit due to thermal shrinkage of the separator can be the separator, and t represents the thickness (cm) of the sepa highly suppressed in the nonaqueous electrolyte battery. ratOr. When the separator has a plurality of shutdown layers. A In the formula (1), when m represents the mass (g/cm) per represents the total thickness of the plurality of shutdown 50 unit area of the shutdown layer and t represents the thickness layers. When the separator has a plurality of heat-resistant (cm) of the shutdown layer, the porosity P (%) of the shut layers, B represents the total thickness of the plurality of down layer can be determined. The porosity of the shutdown heat-resistant layers. layer obtained in this manner is preferably 30 to 70%. Specific values of A and B are as follows. The thickness of In the formula (1), when m represents the mass (g/cm) per the shutdown layer (the total thickness in the case of a plu 55 unit area of the heat-resistant layer and t represents the thick rality of shutdown layers) is preferably 5 um to 30 um. The ness (cm) of the heat-resistant layer, the porosity P (%) of the thickness of the heat-resistant layer (the total thickness in the heat-resistant layer also can be determined. The porosity of case of a plurality of heat-resistant layers) is in the range of the heat-resistant layer obtained in this manner is preferably preferably 1 um, more preferably 2 Lum, even more preferably 20 to 60%. 4 um to preferably 20 um, more preferably 10 Lum. If the 60 It is desirable that the separator of the present invention has shutdown layer is too thin, the shutdown property may be an air permeability of 30 to 300 sec, which is indicated by the weakened. If the shutdown layer is too thick, the energy Gurley value. The Gurley value is obtained by a method density of the battery may be reduced, and also the effect of according to JIS P 8117 and expressed as the length of time Suppressing thermal shrinkage of the whole separator may be (seconds) it takes for 100 ml air to pass through a membrane reduced because the force of the thermal shrinkage is 65 at a pressure of 0.879 g/mm. If the air permeability is too increased when the separator has a structure in which the large, the ion permeability can be reduced. On the other hand, heat-resistant layer is integrated with the shutdown layer. if the air permeability is too small, the strength of the sepa Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 85 of 90 PageID: 85 US 9, 166,251 B2 11 12 rator can be reduced. It is desirable that the strength of the nonaqueous electrolyte battery. Examples of the negative separator is penetrating strength measured using a 1 mm active material include mixtures of two or more carbon mate diameter needle, and that the penetrating strength is 50 g or rials capable of intercalating and deintercalating lithium Such more. If the penetrating strength is too small, lithium dendrite as graphite, pyrolytic carbon, coke, glassy carbon, a calcined crystals may penetrate the separator when they are produced, organic polymer compound, mesocarbon microbeads, and a thus leading to a short circuit. The separator having the mul carbon fiber. Moreover, examples of the negative active mate tilayer structure as described above can ensure the air perme rial also include the following: alloys of Si, Sn, Ge, Bi, Sb, ability and the penetrating strength. and In; compounds that can be charged/discharged at a low The separator of the present invention can be produced in Voltage close to lithium metal such as a lithium-containing the following manner. For example, the heat-resistant fine 10 nitride and a lithium-containing oxide; a lithium metal; and a particles, the binder, etc. constituting the heat-resistant layer Li/Ai alloy. The negative electrode may be produced in such are dispersed in a dispersion medium, namely an organic a manner that a negative electrode mixture is obtained by solvent such as water or N-methyl-2-pyrrolidone (NMP) to adding the conductive assistant or the binder (e.g., PVDF) prepare a slurry or paste-like composition for forming the appropriately to the negative active material, and then formed heat-resistant layer (the binder may be dissolved in the dis 15 into a compact (a negative electrode mixture layer) while a persion medium). This composition is applied to the Surface current collector Such as a copper foil is used as a core mate of the shutdown layer and dried. rial. Alternatively, foils of the above alloys or lithium metal When the shutdown layer is a microporous film made of a can be used individually or in the form of a laminate with the thermoplastic resin, the composition for forming the heat current collector (e.g., a copper foil) as the negative electrode. resistant layer can be applied to the surface of the shutdown When the negative electrode of the present invention layer, e.g., by coating the Surface of the microporous film with includes a current collector, the current collector may be, e.g., the composition using a coater or by immersing the a foil, a punched metal, a mesh, or an expanded metal, which microporous film in the composition. are made of copper, nickel, or the like. In general, a cooper When the shutdown layer is composed of aggregated ther foil is used. If the thickness of the whole negative electrode is moplastic resin fine particles, the thermoplastic resin fine 25 reduced to achieve a battery with high energy density, the particles, the binder used as needed, etc. constituting the current collector of the negative electrode preferably has a shutdown layer are dispersed in a dispersion medium Such as thickness of 5 to 30 um. water or an organic solvent to prepare a slurry or paste-like A lead portion of the negative electrode is generally pro composition for forming the shutdown layer (the binder may vided in the following manner. A part of the current collector be dissolved in the dispersion medium). This composition is 30 remains exposed without forming the negative electrode mix applied to a substrate and dried, so that a shutdown layer is ture layer when the negative electrode is produced, and this formed beforehand. Subsequently, the composition for form exposed portion can serve as the lead portion. However, the ing the heat-resistant layer can be applied to the Surface of this lead portion does not necessarily need to be integrated with shutdown layer in the same manner as the microporous film. the current collector from the beginning and may be provided The separator also can be produced in a manner contrary to 35 by connecting a copper foil or the like to the current collector the above. That is, the composition for forming the heat afterward. resistant layer is applied to a substrate and dried, so that a The nonaqueous electrolyte of the present invention can be heat-resistant layer is formed beforehand. Subsequently, the a nonaqueous electrolyte (nonaqueous electrolytic solution) composition for forming the shutdown layer is applied to the produced by dissolving at least one lithium salt selected from surface of this heat-resistant layer and dried. 40 the group consisting of LiClO, LiPF, LiBF, LiASF The heat-resistant layer and the shutdown layer can be LiSbF LiCFSO, LiCFCO, LiCF (SO), LiN simultaneously formed by applying one of the compositions (CFSO), LiC(CFSO), LiCriFSO, (2sins.5), and LiN for forming the heat-resistant layer and the shutdown layer to (RfCSO) (where Rf represents a fluoroalkyl group) in an a Substrate, and then applying the other composition before organic solvent Such as a dimethyl carbonate, a diethyl car the previously applied composition is completely dried. 45 bonate, a methyl ethyl carbonate, methyl propionate, an eth When the heat-resistant layer includes the porous base ylene carbonate, a propylene carbonate, abutylene carbonate, material, the composition for forming the heat-resistant layer Y-butyrolactone, ethylene glycol Sulfite, 1,2-dimethoxy may be applied to the porous base material or the porous base ethane, 1,3-dioxolane, tetrahydrofuran, 2-methyltetrahydro material may be immersed in the composition, and then the furan, or diethyl ether. The concentration of the lithium salt in composition is dried to form the heat-resistant layer. 50 the electrolyte is preferably 0.5 to 1.5 mol/l, and more pref As described above, the heat-resistant layer and the shut erably 0.9 to 1.25 mol/l. down layer are not necessarily integrated, but can be indepen The nonaqueous electrolyte battery of the present inven dent of each other and laminated together in the battery. tion may be in the form of a rectangular or circular cylinder Moreover, one or both of the heat-resistant layer and the and have an outer can made of steel or aluminum. Moreover, shutdown layer may be integrated with the electrode (positive 55 the nonaqueous electrolyte battery may be a soft package electrode or negative electrode). To integrate the heat-resis battery using a metal-deposited laminated film as an outer tant layer or the shutdown layer with the electrode, e.g., the package. heat-resistant layer or the shutdown layer serving as an inde The electrode used in the nonaqueous electrolyte battery of pendent film can be laminated with the electrode, or the the present invention may be in the form of a laminated composition for forming the heat-resistant layer or the shut 60 electrode body obtained by laminating the positive electrode down layer can be applied to the electrode, thereby forming and the negative electrode via the separator of the present the heat-resistant layer or the shutdown layer. It is preferable invention or in the form of a wound electrode body obtained that the heat-resistant layer is integrated with the shutdown by winding the laminated electrode body. In this case, since layer because a conventional manufacturing process can be the thermal shrinkage of a conventional separator is large in used to produce a battery. 65 the width direction, the width W of the separator needs to be The negative electrode of the battery of the present inven much larger than the width W, of the negative electrode to tion is not particularly limited as long as it can be used for the prevent a short circuit at high temperatures. On the other Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 86 of 90 PageID: 86 US 9, 166,251 B2 13 14 hand, the thermal shrinkage of the separator of the present nism for discharging the gas contained in the battery to the invention in the width direction can be sufficiently suppressed outside at the time the internal pressure is raised due to a rise even if the heat-resistant layer is integrated with the shutdown in temperature or the like. layer to form the separator. Therefore, in the above wound In the nonaqueous electrolyte battery shown in FIGS. 1A, electrode body, a short circuit due to contact between the 1B, and 2, the positive electrode lead 7 is directly welded to positive electrode and the negative electrode can be prevented the cover 9, so that the outer can 20 and the cover 9 can only by making the width W of the separator slightly larger function as a positive terminal. Moreover, the negative elec than the width W, of the negative electrode. trode lead 8 is welded to the lead plate 13, and thus electrically When the shutdown layer is made of a material having connected to the terminal 11 via the lead plate 13, so that the Somewhat inferior resistance to oxidation Such as polyolefin, 10 terminal 11 can function as a negative terminal. However, the it is desirable to avoid contact between the shutdown layer positive and negative electrodes may be reversed depending and the positive active materialso as to prevent degradation of on the material of the outer can 20 or the like. the separator caused by oxidation and improve the charge The nonaqueous electrolyte battery of the present inven discharge cycle life and the high-temperature storage charac tion can be used in the same application as that of a conven teristics of the battery. In particular, when the charging poten 15 tional nonaqueous electrolyte battery. tial is 4.3 V or more, the oxidation action becomes prominent. Next, the present invention will be described in detail by Moreover, when the shutdown layer is located on the negative way of examples. However, the present invention is not lim electrode side, particularly is brought into contact with the ited to the following examples. negative electrode mixture layer, a film of the thermoplastic resin of the shutdown layer is formed on the surface of the Example 1 negative electrode mixture layer after a shutdown is effected. This can suppress a reaction between the air that flows into the Production of Positive Electrode battery, e.g., after a cleavable vent has opened (as will be described later) and the negative active material, and thus can A positive electrode mixture containing paste was prepared further improve the safety at high temperatures. 25 by mixing 90 parts by mass of LiCoos Nio, MnO (posi Hereinafter, an example of the nonaqueous electrolyte bat tive active material), 7 parts by mass of acetylene black (con tery of the present invention will be described with reference ductive assistant), and 3 parts by mass of PVDF (binder) to the drawings. FIG. 1A is a schematic plan view of the uniformly by using NMP as a solvent. This paste was inter nonaqueous electrolyte battery of the present invention. FIG. mittently applied to both surfaces of a current collector (alu 1B is a schematic cross-sectional view of the nonaqueous 30 minum foil) with a thickness of 15 um so that the applied electrolyte battery of the present invention. FIG. 2 is a sche length was 280 mm on the upper surface and 210 mm on the matic diagram showing the appearance of the nonaqueous lower surface, which then was dried and calendered. Thus, the electrolyte battery of the present invention. thicknesses of the positive electrode mixture layers were In the battery shown in FIGS. 1A, 1B, and 2, a negative adjusted so that the total thickness was 150 um. Subsequently, electrode 1 and a positive electrode 2 are wound via a sepa 35 this current collector having the positive electrode mixture rator 3 of the present invention in a spiral fashion, and then layers was cut into a length of 300 mm and a width of 43 mm. pressed into a flat shape, thereby providing a wound electrode thereby producing a positive electrode. Moreover, a lead por body 6. The wound electrode body 6, together with a non tion was formed by welding a tab to the exposed portion of the aqueous electrolyte, is housed in a rectangular cylindrical aluminum foil of the positive electrode. outer can 20. For the sake of simplicity, FIG. 1B does not 40 US 9, 166,251 B2 15 16 slurry was applied to a polyethylene microporous film (with a wound electrode body was formed so that the polyethylene thickness of 16 um, a porosity of 40%, an average pore microporous film was located between the heat-resistant diameter of 0.02 um, and a melting point of 135°C.) using a layer of the positive electrode and the negative electrode. In micro-gravure coater and dried, so that cross-links were this example, the heat-resistant layer formed on the surface of formed by the acrylic resin. Thus, a separator that had a the positive electrode and the polyethylene microporous film thickness of 20 um and included a heat-resistant layer con (shutdown layer) corresponded to the separator. taining boehmite and a shutdown layer formed of the poly ethylene microporous film (with a melting point of 135° C.) Example 4 was produced. Then, the separator was cut into a width of 47 mm and used to produce a battery. 10 Production of Negative Electrode US 9, 166,251 B2 17 18 Measurement of Heat Generation Starting Temperature of a PET film, which had been subjected to a peeling treatment, Positive Electrode and dried to form a heat-resistant layer. Then, this heat-resis The heat generation starting temperature of the positive tant layer was removed from the PET film. Comparing the electrode in each of the nonaqueous electrolyte batteries of heat-resistant layer and the polyethylene microporous film, a Examples 1 to 4 and Comparative Examples 1 to 3 was 5 measured using a DSC “Pyris 1” manufactured by Perki Smaller value of the thermal shrinkage ratios and a larger nElmer Co., Ltd. Each of the nonaqueous electrolyte batteries value of the changes in the Gurley value were selected as the charged to 4.25 V was disassembled in a glove box having an thermal shrinkage ratio and the shutdown temperature of the Ar atmosphere, and the positive electrode was taken out and separator of Example 3, respectively. punched into a circular shape with a diameter of 3.5 mm. This 10 Table 1 also shows the width of each of the separators after positive electrode was weighed and then sealed in a sample the thermal shrinkage at TC. in Examples 1, 2, and 4 and pan that had a gold-plated Surface and was able to withstand Comparative Examples 1 to 3, and the width of the heat 150 atm. Next, the temperature was raised from 30 to 400°C. resistant layer after the thermal shrinkage at TC. in Example at 10° C./min, and a DSC curve was obtained. In the DSC 3. TABLE 1 Heat generation starting Thermal Width of separator temperature of Shutdown shrinkage or heat-resistant positive electrode temperature ratio at T. C. layer at T. C. (° C.) (° C.) To C. (%) (mm) Example 1 229 135 2OO 2 46.1 Example 2 200 135 190 O 47 Example 3 229 135 2OO O 47 Example 4 220 135 2OO 1 46.5 Comparative 229 140 2OO 35 30.6 Example 1 Comparative 161 135 151 1 46.5 Example 2 Comparative 229 2OO O 47 Example 3 curve, the heat generation starting temperature of the positive As can be seen from Table 1, the heating characteristics of electrode indicated a temperature at an intersection point of all the batteries of Examples 1 to 4 were satisfactory. On the two lines: one is an extension line of the base line on the high other hand, the battery of Comparative Example 1 used the temperature side; and the other is a tangent to the curve of the 35 separator including no heat-resistant fine particle, and there exothermic peak on the low temperature side at a point where fore the thermal shrinkage ratio was 35% at T. C., and the the curve has the maximum slope. Table 1 shows the results. width of the separator was smaller than 45 mm, which was the Measurement of Thermal Shrinkage Ratio at TC. width of the negative electrode. In the battery of Comparative The separator used in each of the nonaqueous electrolyte 40 Example 2, the heat generation starting temperature of the batteries of Examples 1 to 4 and Comparative Examples 1 to positive electrode was below 180° C. Moreover, the battery of 3 was allowed to standinathermostatic bath at TC. that was Comparative Example 3 used the separator including no ther 10°C. lower than the heat generation starting temperature of moplastic resin, and therefore a shutdown was not effected. the positive electrode (where the upper limit of T was 200°C.) Evaluation of Charge-Discharge Characteristics for 1 hour. Then, the thermal shrinkage ratio of the separator 45 The nonaqueous electrolyte batteries of Examples 1 to 4 was measured by the above-described method. Table 1 shows and Comparative Examples 1 to 3 were initially charged by the results along with T. C. performing a constant-current and constant-Voltage charge so Measurement of Shutdown Temperature that a constant-current charge was performed at a current The separator used in each of the nonaqueous electrolyte value of 150 mA at 25°C. until the voltage reached 4.2V, and batteries of Examples 1 to 4 and Comparative Examples 1 to 50 Subsequently a constant-voltage charge was performed at a 2 was placed in a thermostatic bath and heated by raising the voltage of 4.2 V. The duration of the initial charge (i.e., the temperature from 100° C. in 5°C. increments for 10 minutes, total charge time) was 12 hours. Next, a constant-current and subsequently the Gurley value was measured. Next, discharge was performed on these batteries at a current value changes in the Gurley value before and after the heating of the of 150 mA and a final voltage of 3.0 V. Moreover, for each of separator in the thermostatic bath were determined, and a 55 the discharged batteries, a constant-current and constant-volt temperature at which the Gurley value was at least ten times age charge was performed (for a duration of 2.5 hours) so that larger than that before heating was defined as the shutdown a constant-current charge was performed at a current value of temperature. The Gurley value was obtained by a method 500 mA until the voltage reached 4.2 V, and subsequently a according to JIS P 8117 and expressed as the length of time constant-voltage charge was performed at a Voltage of 4.2 V. (seconds) it took for 100 ml air to pass through a membrane at 60 Further, a constant-current discharge was performed on these a pressure of 0.879 g/mm. batteries at a current value of 500 mA and a final voltage of 3.0 With respect to the separator of Example 3, the thermal V. Then, the charge/discharge characteristics of each of the shrinkage ratio and the change of the Gurley value were batteries were evaluated. determined for each of the heat-resistant layer and the poly As a result of the evaluation of the charge/discharge char ethylene microporous film used in Example 3. In this case, the 65 acteristics, the batteries of Examples 1 to 4 and Comparative heat-resistant layer was prepared in the following manner. Examples 1 to 2 had good charge/discharge characteristics. The slurry for forming the heat-resistant layer was applied to However, the battery of Comparative Example 3 caused a Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 89 of 90 PageID: 89 US 9, 166,251 B2 19 20 short circuit during the initial charge and could not be and a proportion of particles with a particle size of 2 um charged. Therefore, the subsequent evaluation of the battery or more in the heat-resistant fine particles is 10 vol% or of Comparative Example 3 ceased. less, and Heat Test a shutdown is effected in a range of 135° C. to 150° C. For the nonaqueous electrolyte batteries of Examples 1 to 5 2. The battery separator according to claim 1, wherein a 4 and Comparative Examples 1 to 2, a constant-current and thermal shrinkage ratio in a width direction is 10% or less at constant-voltage charge was performed in Such a manner that 2000 C. each of the batteries was charged at a constant current of 0.2 3. The battery separator according to claim 1, wherein the C until the Voltage reached 4.25 V, and Subsequently charged content of the heat-resistant fine particles in the heat-resistant 10 layer is 80 vol% or more of the total volume of components at a constant voltage of 4.25 V. The duration of this constant in the heat-resistant layer. current and constant-voltage charge was 8 hours. Each of the 4. The battery separator according to claim 1, wherein the charged batteries was allowed to stand in a thermostatic bath heat-resistant fine particles are inorganic fine particles. at 165° C. for 3 hours, and the surface temperature of the 5. The battery separator according to claim 4, wherein the battery was observed. Table 2 shows the results. 15 inorganic fine particles include fine particles of at least one selected from the group consisting of alumina, silica, BaTiO, TABLE 2 boehmite, Zeolite, and kaoline. Surface temperature of 6. The battery separator according to claim 1, wherein the battery after heat test heat-resistant fine particles include plate-like particles. Example 1 No anomaly 7. The battery separator according to claim 1, wherein the Example 2 No anomaly heat-resistant layer has a thickness of 2 um to 6 um. Example 3 No anomaly 8. The battery separator according to claim 1, wherein the Example 4 No anomaly thermoplastic resin includes polyolefin. Comparative Example 1 The temperature was raised. Comparative Example 2 The temperature was raised. 9. The battery separator according to claim 1, wherein the 25 heat-resistant fine particles have an average particle size of 1.5 um or less. As can be seen from Table 2, no anomaly was observed in 10. A nonaqueous electrolyte batter comprising: the nonaqueous electrolyte batteries of Examples 1 to 4 dur a positive electrode having a positive active material ing the heat test at 165° C. Accordingly, the batteries of capable of intercalating and deintercalating a lithium Examples 1 to 4 are superior to the batteries of Comparative 30 1On; Examples 1 to 2 in their safety when allowed to stand at high a negative electrode having a negative active material temperatures. capable of intercalating and deintercalating a lithium The invention may be embodied in other forms without 1On; departing from the spirit or essential characteristics thereof. a separator interposed between the positive electrode and The embodiments disclosed in this application are to be con 35 the negative electrode; and sidered in all respects as illustrative and not limiting. The a nonaqueous electrolyte, Scope of the invention is indicated by the appended claims wherein a heat generation starting temperature of the posi rather than by the foregoing description, and all changes that tive electrode is 180° C. or higher, and come within the meaning and range of equivalency of the wherein the separator is the battery separator according to claims are intended to be embraced therein. 40 claim 1. 11. The nonaqueous electrolyte battery according to claim INDUSTRIAL APPLICABILITY 10, wherein a thermal shrinkage ratio of the separator is 10% or less at a temperature T (C.) that is 10°C. lower than the As described above, the present invention can provide a heat generation starting temperature of the positive electrode battery separator that can constitute a nonaqueous electrolyte 45 (where an upper limit of T is 200°C.). battery having excellent safety in a high-temperature envi 12. The nonaqueous electrolyte battery according to claim ronment, and a nonaqueous electrolyte battery using the bat 10, wherein a width of the separator is larger than that of the tery separator. negative electrode at a temperature T (C.) that is 10° C. lower than the heat generation starting temperature of the The invention claimed is: 50 positive electrode (where an upper limit of T is 200° C.). 1. A battery separator comprising: 13. The nonaqueous electrolyte battery according to claim heat-resistant fine particles; and 10, wherein the positive active material is at least one selected a thermoplastic resin, from the group consisting of the following: a spinel-type wherein the heat-resistant fine particles along with a binder lithium-containing complex oxide expressed as a general for constitute a heat-resistant layer, 55 mula Li,Mn2-M',O4 (where M' is at least one element the thermoplastic resin constitutes a shutdown layer selected from the group consisting of Fe, Ni, Mg., Zn, Co, Cr, formed of a heat-shrinkable microporous film, Al, B. V. Si, Sn, Nb, Ta, Cu, Mo, Ti, and W. -0.1sts 0.1, and the heat-resistant layer and the shutdown layer are inte 0sXs0.6); an olivine-type lithium-containing complex oxide grated into a multilayer structure, expressed as a general formula LiMPO (where M is Co, Ni, the shutdown layer has a thickness A (um) of 5 to 30, the 60 Mn, or Fe); a lithium-containing complex oxide having a heat-resistant layer has a thickness B (Lm) of 1 to 10, a layered crystal structure expressed as a general formula sum of A and B is 6 to 23, and a ratio A/B is 1/2 to 4, Li M 2,Mncos-Nicos O2 (where M is at least one ele a content of the heat-resistant fine particles in the heat ment selected from the group consisting of Fe, Mg., Zn, Co. resistant layer is 50 vol% or more of a total volume of Cr,Al, B.V. Si, Sn, Nb, Ta, Cu, Mo, Ti, and W. -0.1<0.1, and components in the heat-resistant layer, 65 0.sbs0.05); and a lithium-containing complex oxide a proportion of particles with a particle size of 0.2 Lum or expressed as a general formula Li-Ni----s/2 less in the heat-resistant fine particles is 10 vol% or less Mn. 1---oy2M.O. (where M is at least one element Case 2:21-cv-08461 Document 1 Filed 04/06/21 Page 90 of 90 PageID: 90 US 9, 166,251 B2 21 22 selected from the group consisting of Ti, Cr, Fe, Co, Cu, Zn, 26. The battery separator according to claim 1, wherein the Al. Ge. Sn, Mg, and Zr, -0.1 sys0.1, -0.05so.s0.05, heat-resistant line particles have an average particle size of 0