US008292974B2

(12) United States Patent (10) Patent No.: US 8,292,974 B2 Chen et al. (45) Date of Patent: Oct. 23, 2012

(54) SURFACE MODIFICATION AGENTS FOR 6,858,351 B2 2/2005 Miura et al. LITHIUM BATTERIES 7,105,254 B2 9/2006 Oyama 7,235,331 B2 6/2007 Noda et al. 2005, OO1967O A1 1/2005 Amine et al. (75) Inventors: Zonghai Chen, Bolingbrook, IL (US); 2005/0221 168 A1 10, 2005 Dahn et al. Khalil Amine, Oakbrook, IL (US); Ilias 2005/0221196 A1 10, 2005 Dahn et al. Belharouak, Bolingbrook, IL (US) 2005/0227143 A1 10, 2005 Amine et al. 2006, O147809 A1 7/2006 Amine et al. (73) Assignee: UChicago Argonne, LLC, Chicago, IL 2006/0199080 A1 9, 2006 Amine et al.

(US) 3878. A 338 XA,a - 2007/0178370 A1 8, 2007 Amine et al. (*) Notice: Subject to any disclaimer, the term of this 2007/0235259 A1 10, 2007 Tolliver et al. patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days. FOREIGN PATENT DOCUMENTS KR 102OOOOO22943 4/2000 (21) Appl. No.: 13/397,319 KR 10200601-16852 11, 2006 WO WO-2005/083828 A1 9, 2005 (22) Filed: Feb. 15, 2012 WO WO-2006/065605 6, 2006 a lavs OTHER PUBLICATIONS (65) Prior Publication Data Notice of Allowance issued in U.S. Appl. No. 12/454,173 and mailed US 2012/O 148731 A1 Jun. 14, 2012 Mar. 20, 2012. O O U.S. Appl. No. 10/857,365, filed Jan. 27, 2005, Amine et al. Related U.S. Application Data U.S. Appl. No. 1 1/279,120, filed Oct. 11, 2007, Tolliver et al. (63) Continuation of application No. 12/454,173, filed on Final Office Action from U.S. Appl. No. 12/454,173, mailed Dec. 6. May 13, 2009, now Pat. No. 8,187,746. 2011, 16 pages. International Preliminary Report on Patentability and Written Opin (60) Provisional application No. 61/127,901, filed on May ion from PCT/US2007/084481, mailed Jun. 25, 2009. 16, 2008. Non-Final Office Action from U.S. Appl. No. 12/454,173, mailed Aug. 19, 2011, 21 pages. (51) Int. Cl. HOLM 4/82 (2006.01) Primary Examiner — Roy King HOLM 4/02 (2006.01) Assistant Examiner — Carlos Barcena HOLM 4/13 (2010.01) (74) Attorney, Agent, or Firm — Foley & Lardner LLP (52) U.S. Cl...... 29/623.5; 429/209; 429/212:429/213; 429/218.1; 252/182.1; 427/58 (57) ABSTRACT (58) Field of Classification Search ...... 429/209, Y 2012 is is is427/58. 29/623.1,7.25/1821. 623.5 materialA method including includes providingmodifying a a solutionsurface ofor an a electrodeSuspension active of a See application file for complete search history Surface modification agent; providing the electrode active material; preparing a slurry of the Solution or Suspension of (56) References Cited the Surface modification agent, the electrode active material, a polymeric binder, and a conductive filler, casting the slurry U.S. PATENT DOCUMENTS in a metallic current collector; and drying the cast slurry. 4,857.423 A 8, 1989 Abraham et al. 6,677,082 B2 1/2004 Thackeray et al. 11 Claims, 1 Drawing Sheet U.S. Patent Oct. 23, 2012 US 8,292,974 B2

US 8,292,974 B2 1. 2 SURFACE MODIFICATION AGENTS FOR Some embodiments, the Surface modification agent is a silane, LITHIUM BATTERIES organometallic compound, or a mixture of two or more thereof. CROSS-REFERENCE TO RELATED In other embodiments, the Surface modification agent is a APPLICATIONS silane, and the silane has Formula I, II, III, IV, or a mixture of any two or more thereof: This application is a continuation patent application of U.S. Ser. No. 12/454,173, filed on May 13, 2009 now U.S. Pat. No. 8,187,746, which in turn claims the benefit of U.S. Provisional Application No. 61/127,901, filed May 16, 2008, 10 R1 both which are incorporated herein by reference, in their X-Si-R2 entirety, for any and all purposes. R3 GOVERNMENT RIGHTS II 15 R1 The United States Government has rights in this invention x-i- pursuant to Contract No. W-31-109-ENG-38 between the X2 United States Government and The University of Chicago III and/or pursuant to Contract No. DE-AC02-06CH11357 R1 between the United States Government and UChicago Argonne, LLC representing Argonne National Laboratory. x-i-x X2 FIELD IV 25 X4 The present invention generally relates to lithium recharge able batteries. More particularly, Surface modification agents x-i-x for electrodes are described. X2 V BACKGROUND 30 -O-Si-R2i There has been growing interest in developing safe, high power lithium ion batteries for transportation applications, k such as hybrid electric vehicles (HEV) and plug-in hybrid electric vehicles (PHEV). Among the available portable 35 wherein: energy storage solutions, lithium ion batteries have the high X', X, X and X’ are independently —Cl, Br oralkoxyl est energy density, and as a result, lithium ion batteries are a groups: likely candidate for use in transportation applications. Yet, R", R, and Rare independently ahalogen, a substituted or there are technical barriers for using lithium ion batteries in unsubstituted alkyl group, a Substituted or unsubstituted Such applications. 40 aryl group, an OR group, or a group of Formula V; and Technological barriers related to the use of lithium ion R is a substituted or unsubstituted alkyl group, or a sub batteries, include power capability concerns. As batteries stituted or unsubstituted aryl group. In some Such decrease in size and cost, the power capability of the batteries embodiments, at least one of substitution groups R', R, must remain high. In other words, for a battery to find appli and R is a substituted alkyl group that is an ethylene cation as a transportation power source, the battery needs to 45 oxide moiety of Formula VI: exhibit a enough power capability to power the vehicles or accept energy from braking vehicles. A certain amount of gas is generated inside a battery due to VI the interfacial reactions inside a lithium ion battery, such as formation of solid electrolyte interphases (SEI) during for 50 "s"--N-N R6 mation or decomposition of old SEI layers at elevated tem peratures. The generation of gas may lead to a slow degrada tion of electrode materials, or a reduction in the active wherein: electrochemical Surface area (i.e., an increase in impedance) m is an integer from 0 to 10; by blocking the charge/ion transport pathways. When gas 55 n is an integer from 1 to 10; and accumulates in a battery cell, the power capability of the cell R is a substituted or unsubstituted alkyl group, a substi is then concomitantly deteriorated. Nano-structured tuted or unsubstituted aryl group, or a carbonate-based Li TiO2 can be a safe negative electrode material with high sub group of Formula VII: power capability and capacity retention. However, significant amount of gas is observed at elevated temperatures when 60 nano-structured Li TisC) was used against lithium manga VII nese oxide spinels. -(CH2). SUMMARY O)- 65 In one aspect, an active material for an electrochemical device having a surface modification agent is provided. In US 8,292,974 B2 3 4 wherein zirconium (IV), tetrakis(ethylmethylamido)Zirconium (IV), R’ is hydrogen, a substituted or unsubstituted alkyl zirconium(IV) bromide, zirconium(IV) chloride, zirconium group having from 1 to 12 carbon atoms; a Substi (IV) tert-butoxide, and a mixture of any two or more thereof. tuted or unsubstituted alkenyl group having from 2 In other embodiments, the Surface modification agent is to 8 carbon atoms; and cyclic organic compound that can under ring opening cou q is an integer from 0 to 8. pling reaction with acidic groups like —OH; at least one of In other embodiments, the Surface modification agent is a the chemical bonds in the cyclic organic compound is sensi metal alkoxide, a metal halide, a metal alkyl, a metal alkyla tive to acidic groups; when reacting with acidic group, the mide, a carbonyl metal compound, a metal aryl, a metal ring will be opened at the specific site and undergo coupling cyclopentadienyl, a phosphine, a metal phosphine, a metal 10 reaction with the Surface acidic group without forming resi hydride, or a mixture of any two or more thereof. due chemicals. An exemplary of Such surface modification In Some embodiments, the Surface modification agent is an agent is, but not limited to, cyclic alkylene oxides and epoxy. organometallic compound of Formula VIII, Formula IX, or a In other embodiments, the Surface modification agent is a mixture thereof: compound selected from the group consisting of ammonia, wherein 15 phosphine, a halophosphine, a alkylphosphine, a haloalky Formula VIII is M-(R): lphosphine, an alkylamine, and a mixture of any two or more Formula IX is M-(O-R): thereof. wherein In some embodiments, the surface of the active material is M is a metal; and alternately treated for 1 to 1000 times with a first and a second Rand Rare each independently hydrogen, a halo Surface modification agents, where the first modification gen, an Substituted or unsubstituted alkoxide agent is selected from the group consisting of the organome group, a Substituted or unsubstituted alkyl group, a tallic compound of Formula VIII, Formula IX, aluminum Substituted or unsubstituted aryl group, a Substi sec-butoxide, aluminum tribromide, aluminum trichloride, tuted or unsubstituted aminealkyl group, and diethylaluminum ethoxide, tris(ethylmethylamido)alumi p is an integer from 1 to 6. 25 num, triethylaluminum, triisobutylaluminum, trimethylalu In other embodiments, the Surface modification agent is a minum, tris(diethylamido)aluminum, tris(ethylmethyla compound selected from the group consisting of aluminum mido)aluminum, trimethylarsine, diborane, trimethylboron, sec-butoxide, aluminum tribromide, aluminum trichloride, bis(N,N'-diisopropylacetaminato)cobalt (II), dicarbonyl(cy diethylaluminum ethoxide, tris(ethylmethylamido)alumi clopentadienyl)cobalt (I), (N,N'-diisopropylacetaminato) num, triethylaluminum, triisobutylaluminum, trimethylalu 30 copper (II), bis(N,N'-di-tert-butylacetamidinato)iron (II), minum, tris(diethylamido)aluminum, tris(ethylmethyla gallium tribromide, gallium trichloride, triethylgallium, tri mido)aluminum, trimethylarsine, diborane, trimethylboron, isopropylgallium, trimethylgallium, tri(dimethylamido)gal bis(N,N'-diisopropylacetaminato)cobalt (II), dicarbonyl(cy lium, tri-tert-butylgallium, digermane, germane, tetrameth clopentadienyl)cobalt (I), (N,N'-diisopropylacetaminato) ylgermanium, hafnium (IV) chloride, hafnium (IV) tert copper (II), bis(N,N'-di-tert-butylacetamidinato)iron (II), 35 butoxide, tetrakis(diethylamido)hafnium (IV), tetrakis gallium tribromide, gallium trichloride, triethylgallium, tri (dimethylamido)hafnium (IV), tetrakis(ethylmethylamido) isopropylgallium, trimethylgallium, tri(dimethylamido)gal hafnium (IV), indium trichloride, indium(I) iodide, indium lium, tri-tert-butylgallium, digermane, germane, tetrameth acetylacetonate, triethylindium, tris(N,N'-Di-tert-butylaceta ylgermanium, hafnium (IV) chloride, hafnium (IV) tert midinato)lanthanum (III), bis(pentaethylcyclopentadienyl) butoxide, tetrakis(diethylamido)hafnium (IV), tetrakis 40 magnesium, molybdenum hexacarbonyl, molybdenum (V) (dimethylamido)hafnium (IV), tetrakis(ethylmethylamido) chloride, molybdenum (VI) fluoride, N,N-dimethylhydra hafnium (IV), indium trichloride, indium (I) iodide, indium Zine, ammonia, azidotrimethylsilane, niobium (V) chloride, acetylacetonate, triethylindium, tris(N,N'-Di-tert-butylaceta niobium (V) ethoxide, bis(methylcyclopentadienyl)nickel midinato)lanthanum (III), bis(pentaethylcyclopentadienyl) (II), phosphine, tert-butylphosphine, tris(trimethylsilyl)phos magnesium, molybdenum hexacarbonyl, molybdenum (V) 45 phine, cyclopentadienyl(trimethyl)platinum (IV), bis(ethyl chloride, molybdenum (VI) fluoride, N,N-dimethylhydra cyclopentadienyl)ruthenium (II), trimethylantimony, tris Zine, ammonia, azidotrimethylsilane, niobium (V) chloride, (dimethylamido)antimony, 2,4,6,8- niobium (V) ethoxide, bis(methylcyclopentadienyl)nickel tetramethylcyclotetrasiloxane, dimethoxydimethylsilane, (II), phosphine, tert-butylphosphine, tris(trimethylsilyl)phos disilane, methylsilane, octamethylcyclotetrasiloxane, silane, phine, cyclopentadienyl(trimethyl)platinum (IV), bis(ethyl 50 tris(isopropoxy)silanol, tris(tert-butoxy)silanol, tris(tert-pen cyclopentadienyl)ruthenium (II), trimethylantimony, tris toxy)silanol, pentakis(dimethylamido)tantalum (V), tanta (dimethylamido)antimony, 2,4,6,8- lum (V) chloride, tantalum (V) ethoxide, tris(diethylamino) tetramethylcyclotetrasiloxane, dimethoxydimethylsilane, (tert-butylimido)tantalum (V), bis(diethylamido)bis disilane, methylsilane, octamethylcyclotetrasiloxane, silane, (dimethylamido)titanium (IV), tetrakis(diethylamido) tris(isopropoxy)silanol, tris(tert-butoxy)silanol, tris(tert-pen 55 titanium(IV), tetrakis(dimethylamido)titanium (IV), tetrakis toxy)silanol, pentakis(dimethylamido)tantalum (V), tanta (ethylmethylamido)titanium (IV), titanium (IV) bromide, lum (V) chloride, tantalum (V) ethoxide, tris(diethylamino) titanium(IV) chloride, titanium(IV) tert-butoxide, vanadium (tert-butylimido)tantalum (V), bis(diethylamido)bis (V) oxytriisopropoxide, bis(tert-butylimido)bis(dimethyla (dimethylamido)titanium (IV), tetrakis(diethylamido) mido)tungsten (VI), tungsten hexacarbonyl, tungsten (VI) titanium(IV), tetrakis(dimethylamido)titanium(IV), tetrakis 60 chloride, tungsten (VI) fluoride, tris(N.N-bis(trimethylsilyl) (ethylmethylamido)titanium (IV), titanium (IV) bromide, amide)yttrium (III), yttrium (III)butoxide, diethylzinc, tet titanium(IV) chloride, titanium(IV) tert-butoxide, vanadium rakis(diethylamido)Zirconium (IV), tetrakis(dimethylamido) (V) oxytriisopropoxide, bis(tert-butylimido)bis(dimethyla zirconium (IV), tetrakis(ethylmethylamido)Zirconium (IV), mido)tungsten (VI), tungsten hexacarbonyl, tungsten (VI) zirconium(IV) bromide, zirconium(IV) chloride, zirconium chloride, tungsten (VI) fluoride, tris(N.N-bis(trimethylsilyl) 65 (IV) tert-butoxide, and a mixture of any two or more thereof amide)yttrium (III), yttrium (III)butoxide, diethylzinc, tet and the second Surface modification agent is selected from the rakis(diethylamido)Zirconium (IV), tetrakis(dimethylamido) group consisting of ammonia, phosphine, a halophosphine, a US 8,292,974 B2 5 6 alkylphosphine, a haloalkylphosphine, an alkylamine, and a times is from 5 to 20. In yet other embodiments, the exposing mixture of any two or more thereof. Surface modification agent is performed by alternately expos In another aspect, an electrode of the above active materials ing two or more surface modification agents. having a surface modification agent are provided. In some In other embodiments, the methods include modifying the embodiments, the electrode is a negative electrode. In other Surface of an electrode active material by providing a gas embodiments, the electrode is a positive electrode. Surface modification agent; providing a radiofrequency dis In another aspect, methods of modifying the Surface of an charge to create a plasma of the gas Surface modification electrode or electrode active material with a surface modifi agent; and contacting the gas Surface modification agent with cation are provided. In some embodiments, the methods the electrode active material. In some Such embodiments, the include modifying the surface of an electrode of a battery by 10 providing a surface modification agent, and adding the Sur gas Surface modification agent is a fluorine-based gas F. face modification agent to a non-aqueous electrolyte; wherein CF2.2. C.F2, or CF2-2 and q" is an integer ranging the battery comprises the electrode and the non-aqueous elec from 1 to 20. In some embodiments, the fluorine-based gas is trolyte. In some such embodiments, a concentration of the CF. In other embodiments, a pressure of the gas Surface Surface modification agent in the non-aqueous electrolyte is 15 modification agent is less than 10 Pa. In other embodiments, from about 0.00001 wt % to 10 wt %. In other embodiments, the gas Surface modification agent is a mixture of CF and an the concentration of the Surface modification agent in the inert gas selected from nitrogen, helium, argon, or a mixture non-aqueous electrolyte is from about 0.0001 wt % to 3 wt %. of any two or more thereof. In some embodiments, a concen In still other embodiments, the concentration of the surface tration of CF in the inert gas is less than about 20%. modification agent in the non-aqueous electrolyte is from In some embodiments, any of the above active materials is about 0.001 wt % to 2 wt %. a positive electrode active material selected from the group In other embodiments, the methods include modifying the consisting of spinel, olivine, carbon-coated olivine, LiFePO, Surface of an electrode laminate by providing a gas phase Li M'M"PO, Li Ni,Mn,Co.Met'sO.F., A.B., Surface modification agent or a solution of a Surface modifi (XO), Vanadium oxide, and mixtures of any two or more cation agent; and exposing the Surface modification agent to 25 thereof, and further wherein the electrode laminate; wherein the solution of the surface M" is selected from the group consisting of V, Cr, Mg, Fe, modification agent is prepared by dissolving or Suspending Co, and Ni; the Surface modification agent in a solvent. In some Such M" is selected from group consisting of IIA, IIIA, IVA, VA, embodiments, the time of the exposing step is from about 0.1 VIA and IIIB metals having an ionic radius less than the second to 24 hours. In other embodiments, the time of the 30 ionic radius of Fe'": exposing step is from about 1 second to 1 hour. In still other Met' is selected from the group consisting of Mg., Zn, Al. embodiments, the time of the exposing step is from about 1 Ga, B, Zr, and Ti; and second to 10 minutes. 0sx's 1, 0sy's 1, 0sz's 1, 0sx"s0.4, Osos 1, In other embodiments, the methods include modifying the 0s Bs1,0sys2,0sös0.2,0sz"s0.5, and 0sn's3. Surface of an electrode active material by providing a solution 35 In some such embodiments, the positive electrode material or a suspension of a Surface modification agent; providing the is coated with Al-O, AlF. ZrO, SiO, MgO, TiO, CaO. electrode active material; preparing a slurry of the Surface SnO, WO, InO, Ga-Os, ScC), Y.O., La O, Hf), modification agent, the electrode active material, a polymeric V.O.s, NbOs, Ta-Os, MnO, MnO, CoO, CoO, NiO, NiO, binder, and a conductive filler; casting the slurry in a metallic CuO, ZnO, MgF, CaF, Mo, Ta, W. Fe, Co, Cu, Ru, Pa, Pt, Al, current collector; and drying the cast slurry. In some Such 40 Si, Se, oxyfluorides, or a mixture of two or more of thereof embodiments, the drying step is carried out at a temperature In some embodiments, any of the above active materials is between about 40°C. and 200°C. In other embodiments, the a negative electrode material selected from the group consist polymeric binder is PVDF, PVDF-HFP or a mixture thereof. ing of graphite, amorphous carbon, Li Tis012, MA, Li In other embodiments, the conductive filler is carbon black, B,TiCO, O, tin alloys, silicon alloys, intermetallic carbon fiber, graphite, a metallic nano powder, or a mixture of 45 compounds, lithium metal, or mixtures of any two or more any two or more thereof. In other embodiments, the concen such materials; and further wherein: tration of the Surface modification agent in the slurry is from M is selected from the group consisting of Ba, Sr, Ca,Mg, about 0.00001 wt % to 5 wt.%. In still other embodiments, the Pb, and Sn; concentration of the Surface modification agent in the slurry is 0sxs0.5,0sys0.5,0szs0.5, 0

Surface Modification Agents where, m is an integer from 0 to 10; n is an integer from 1 to In various aspects, Surface modified active materials, Sur 10; and R is a substituted or unsubstituted alkyl group, a face modification agents and methods to of modifying mate Substituted or unsubstituted aryl group, or a carbonate-based rials that are used in lithium ion batteries, to Suppress gas Subgroup. In some embodiments, the alkyl or aryl groups are release from the batteries, are provided. Such surface modi 10 Substituted with one or more halogens. Exemplary carbonate fication agents include a class of compounds that may selec based subgroups in those represented by Formula VII: tively react with acidic functional groups on the Surface of a material used to manufacture battery electrodes, and to elimi VII nate the chemical or electrochemical reactivity of such func 15 tional groups. While any electrode may be suitable for modi 1. (CH2) O fication, in some embodiments, the electrode is an electrode laminate as are known to those of skill in the art. Such acidic functional groups include, but are not limited to, —OH and R7 O)=oO —COOH. As used herein, a “laminate' electrode is an elec trode constructed from an electrode active material, a con where R is hydrogen, or a group selected from a substituted ductive filler, and a polymeric binder that maintains the physi or unsubstituted alkyl group have from 1 to 12 carbon atoms, cal integrity of the electrode. a Substituted or unsubstituted alkenyl group having from 2 to In general, the Surface modification agents are a group of 8 carbon atoms; and q is an integer from 0 to 8. compounds that can selectively react with Surface functional 25 In other embodiments, the Surface modification agent is an groups on the active materials that form electrodes. In some organometallic compound of Formula VIII or IX, where the embodiments, the Surface modification agent is one or more compound of Formula VIII is M-(R), and the compound of silanes of the formulas represented as Formula I, II, III, IV. Formula IX is M-(O-R), ... In such other embodiments, Mis and V. a metal; each Rand Rare independently hydrogen, a halo 30 gen, an alkoxide group, a Substituted or unsubstituted alkyl group, a Substituted or unsubstituted aryl group, or an alky lamine group; and p is an integer from 1 to 6. In some embodi ments, the alkyl or aryl groups are Substituted with one or X-Si-R2i more halogens. 35 Suitable organometallic compounds of Formulas VIII and IX include, but are not limited to, metal alkoxides, metal II halides, metal alkyls, metal alkylamides, carbonyl metal R1 compounds, metal aryls, metal cyclopentadienides, phos phines, metal phosphines, metal hydrides, and the like. For x-i-R 40 example, some compounds of Formula VIII and IX include, X2 but are not limited to aluminum sec-butoxide, aluminum tri III bromide, aluminum trichloride, diethylaluminum ethoxide, R1 tris(ethylmethylamido)aluminum, triethylaluminum, tri isobutylaluminum, trimethylaluminum, tris(diethylamido) x-i-x 45 aluminum, tris(ethylmethylamido)aluminum, trimethylars X2 ine, diborane, trimethylboron, bis(N,N'- IV diisopropylacetaminato)cobalt (II), dicarbonyl X4 (cyclopentadienyl)cobalt (I), (N,N'-diisopropylacetaminato) X-Si-X copper (II), bis(N,N'-di-tert-butylacetamidinato)iron (II), 50 gallium tribromide, gallium trichloride, triethylgallium, tri k isopropylgallium, trimethylgallium, tri(dimethylamido)gal V RI lium, tri-tert-butylgallium, digermane, germane, tetrameth ylgermanium, hafnium (IV) chloride, hafnium (IV) tert -O-Si-R2 butoxide, tetrakis(diethylamido)hafnium (IV), tetrakis 55 (dimethylamido)hafnium (IV), tetrakis(ethylmethylamido) hafnium (IV), indium trichloride, indium(I) iodide, indium acetylacetonate, triethylindium, tris(N,N'-Di-tert-butylaceta wherein X', X, X and X’ are independently-Cl, Br or midinato)lanthanum (III), bis(pentaethylcyclopentadienyl) alkoxyl groups; R', R, and Rare independently a halogen, magnesium, molybdenum hexacarbonyl, molybdenum (V) a Substituted or unsubstituted alkyl group, a Substituted or 60 chloride, molybdenum (VI) fluoride, N,N-dimethylhydra unsubstituted aryl group, an OR group, or a group of For Zine, ammonia, azidotrimethylsilane, niobium (V) chloride, mula V; andR is a substituted or unsubstituted alkyl group, or niobium (V) ethoxide, bis(methylcyclopentadienyl)nickel a Substituted or unsubstituted aryl group. In some embodi (II), phosphine, tert-butylphosphine, tris(trimethylsilyl)phos ments, the alkyl or aryl groups are Substituted with one or phine, cyclopentadienyl(trimethyl)platinum (IV), bis(ethyl more halogens. In some other embodiments, at least one of 65 cyclopentadienyl)ruthenium (II), trimethylantimony, tris substitution group of R. R. or R contains an ethylene oxide (dimethylamido)antimony, 2,4,6,8- moiety as shown in Formula VI: tetramethylcyclotetrasiloxane, dimethoxydimethylsilane, US 8,292,974 B2 10 disilane, methylsilane, octamethylcyclotetrasiloxane, silane, to polymers such as PVDF (polyvinylidene difluoride), or tris(isopropoxy)silanol, tris(tert-butoxy)silanol, tris(tert-pen co-polymers of PVDF with other materials such as hexafluo toxy)silanol, pentakis(dimethylamido)tantalum (V), tanta ropropylene (PVdF-HFP). lum (V) chloride, tantalum (V) ethoxide, tris(diethylamino) In yet another alternative, Surface modification agents may (tert-butylimido)tantalum (V), bis(diethylamido)bis be directly applied to an active electrode material powder or (dimethylamido)titanium (IV), tetrakis(diethylamido) electrode laminate by exposing the powder or laminate to the titanium(IV), tetrakis(dimethylamido)titanium(IV), tetrakis gas phase, or diluted Solution of the Surface modification (ethylmethylamido)titanium (IV), titanium (IV) bromide, agent. In some other embodiments, the active material pow titanium(IV) chloride, titanium(IV) tert-butoxide, vanadium der is treated with the Surface modification agent and water or (V) oxytriisopropoxide, bis(tert-butylimido)bis(dimethyla 10 moisture to achieve multiple layer modification and to maxi mido)tungsten (VI), tungsten hexacarbonyl, tungsten (VI) mize coverage. Still in Some other embodiments, the active chloride, tungsten (VI) fluoride, tris(N.N-bis(trimethylsilyl) material powder is treated with more than one inventive sur amide)yttrium (III), yttrium (III)butoxide, diethylzinc, tet face modification agents as well as water or moisture to rakis(diethylamido)Zirconium (IV), tetrakis(dimethylamido) introduce new functionalities and to maximize the coverage. 15 In some embodiments, the exposure time of the Surface modi zirconium (IV), tetrakis(ethylmethylamido)Zirconium (IV), fication agent to the active electrode material is from about zirconium(IV) bromide, zirconium(IV) chloride, zirconium 0.1 second to 24 hours, from about 1 second to 1 hour, in other (IV) tert-butoxide. In yet other embodiments, the surface embodiments, or from about 1 second to 10 minutes, in yet modification agent is a compound Such as ammonia, phos other embodiments. phine, a halophosphine, a alkylphosphine, a haloalkylphos In a further alternative, methods of surface modification of phine, an alkylamine, or a mixture of any two or more Such the above materials are provided and may be accomplished compounds. using a gas such as F2, C, F2, 2, C, F, or C.F2, 2 where Methods q" is an integer ranging from 1 to 20, in a reactor with a In another aspect, methods of modifying the Surface chem radiofrequency (R) discharge. For example, CF is one such istry of active materials for a lithium, or lithium ion battery 25 Suitable gas. In general, in Such methods, the gas is used to are provided. There are a number of methods in which the make a plasma which, when in contact with the active mate Surface modification agent may be introduced to the elec rial, grafts fluorinated functionalities directly to the materi trode, or active materials from which the electrode is pro als surface. In the case of CF, the CF plasma grafts fluorine duced. atoms to the active material's Surface by a mechanism that In Such methods, Surface modification agents may be intro 30 involves CF-radical reactions at the surface as well, where q duced to a battery as an additive to non-aqueous electrolytes. is from 1-4. As a general procedure, samples of an active material, such as Li TiO, are placed in the center of a In such embodiments, all the wettable surface area of an chamber where R, discharge occurs using CF, gas. The flow electrode by the electrolyte is exposed to the surface modifi rate of the CF may be widely varied, depending upon the cation agent. Once exposed surface functional groups on the 35 surface modification desired, but is typically on the order of electrodes can be modified by reaction with the surface modi about 10 cm/min. The total gas pressure is typically be less fication agent. By introducing the Surface modification agents than about 10 Pa. In some examples, the power may range to the battery through the electrolyte, negative and positive from about 20 W to 300 W, but is typically about 80 W. The electrodes may be modified simultaneously. In some embodi plasma frequency is typically 13.56 MHz. Temperature may ments, the concentration of the Surface modification agent in 40 also impact the Surface modification and the temperature is the non-aqueous electrolyte is from about 0.00001 wt % to 10 typically less than about 150°C. The time of exposure of the wt %, from about 0.0001 wt % to 3 wt %, in other embodi material to the plasma is typically less than 2 hours. Substan ments, or from about 0.001 wt % to 2 wt %, in yet other tial production of atomic fluorine after the dissociation CF embodiments. gas and improved radical production efficiency can be Alternatively, Surface modification agents may be directly 45 obtained by adjusting the flow rate of the gas, the gas pressure, applied to the electrode by exposing the dry electrode to a gas the temperature of the sample, and the time of exposure of the phase, or dilute solution, of the inventive surface modification material to the plasma. agent. After the exposure, the electrode may be heated to In other embodiments, the surface modification can be remove residual Surface modification agent. carried out by surface fluorination where the material can be In another alternative, Surface modification agents may be 50 put in fluorine reactor and either fluorine gas or a mixture of introduced directly into an electrode slurry from which an fluorine gas and an inert gas is introduced to the reactor to electrode may be produced. In Such embodiments, the elec react with acidic groups at the Surface of the active material. trode slurry is a non-homogeneous mixture of an active posi Inert gases may include helium, nitrogen, argon, and other tive or negative electrode material, a conductive filler, a poly Such gases known to those of skill in the art. The temperature meric binder, and a solvent. Such materials are typically 55 of the reactor should not exceed 120° C. to prevent the decom mixed and cast into electrodes. During the mixing and casting position of the electrode material. In the situation where only process, the Surface modification agents react with Surface fluorine gas is used, the temperature of the reactor is typically functional groups, such as —OH and—COOH, on the active less than 40°C., and the time of fluorination is less than about materials surface. After casting, excess Surface modification 60 min. In the situation where the fluorination of the active agent, and reaction byproducts are removed during the drying 60 materials surface is carried out using a mixture of fluorine process, while the reacted agent is chemically bound to the gas and an inert gas such nitrogen, argon, or other such inert surface of the electrode material, and is not removed by gases, the concentration of fluorine gas in the mixture is less simple heat treatment. Suitable conductive fillers for use in than about 20%, and the temperature is less than about 120° the slurry and electrode include, but are not limited to mate C. The fluorination could be static using a close reactor, or rials such as carbon black, carbon fiber, graphite, or other 65 could be in a form of flowing the gas through the reactor. metallic nanopowder materials. Suitable polymeric binders In any of the above methods, the active material may be for use in the slurry and electrode include, but are not limited repeatedly contacted with the Surface modification agent, US 8,292,974 B2 11 12 until the desired level of modification is achieved. For In some embodiments, the non-aqueous electrolytes example, after the first modification of the active material, include and electrode stabilizing additive to protect the elec Subsequent modifications may be iteratively made on the trodes from degradation. See e.g., co-pending U.S. applica material recovered from the previous iteration. For example, tion Ser. Nos. 10/857,365, 1 1/279,120, and provisional appli the Surface modification agent may be exposed to the elec cation No. 60/647.361. Thus, electrolytes of the invention can trode laminate or the electrode active material a repeat num include an electrode stabilizing additive that can be reduced ber of times ranging from 1 to 1000, or more. In some or polymerized on the Surface of a negative electrode to form embodiments, the repeat number of times, or iterations, is a passivation film on the Surface of the negative electrode. from 3 to 100. In other embodiments, the repeat number of Likewise, inventive electrolytes can include an electrode sta times, or iterations, is from 5 to 20. 10 In another aspect, and as described above, lithium batteries bilizing additive that can be oxidized or polymerized on the may be prepared using the Surface modification agents. Typi surface of the positive electrode to form a passivation film on cally, the batteries include a positive electrode, a negative the surface of the positive electrode. In some embodiments, electrode, and a non-aqueous electrolyte, and either one or electrolytes of the invention further include mixtures of the both of the positive or negative electrode has been modified 15 two types of electrode stabilizing additives. The additives are with a Surface modification agent. The anode and the cathode typically present at a concentration of about 0.001 to 8 wt %. in lithium batteries are typically separated from each other by In Some embodiments, an electrode stabilizing additive is a a porous separator. substituted or unsubstituted linear, branched or cyclic hydro Suitable negative electrodes for lithium batteries include carbon comprising at least one oxygen atom and at least one those having graphite, amorphous carbon, Li TisC), aryl, alkenyl or alkynyl group. The passivating film formed M.A, Li-B, TiCO, O, tin alloys, silicon alloys, from such electrode stabilizing additives may also be formed intermetallic compounds, lithium metal, or mixtures of any from a Substituted aryl compound or a Substituted or unsub two or more such materials. In Such materials, M is selected stituted heteroaryl compound where the additive comprises at from Ba, Sr, Ca, Mg, Pb, Sn and other divalent cations: least one oxygen atom. Alternatively, a combination of two 0sxs0.5,0sys0.5,0szs0.5,0

Example 2 X, X, X and X’ are independently – C1 or - Br; R", R, and Rare independently a halogen, a substituted 10 or unsubstituted alkyl group, a Substituted or unsub FIG. 1 is a composite illustration of a composite photo stituted aryl group, an OR group, or a group of For graph of cells before (C) and after (A,B) charging. Each cell mula V; and is a Li TiO2/LiMnO, lithium-ion cell. Cell (A) was prepared with 1 wt % chloro2-2-(2-methoxyethoxy) R is substituted or unsubstituted alkyl group, or a sub ethoxyethoxydimethylsilane as a surface modification 15 stituted or unsubstituted aryl group. agent, and cell (B) did not contain any surface modification 2. The method of claim 1, wherein the polymeric binder is agent. Cell (C) did not undergo any charging. Cells (A) and PVDF, PVDF-HFP, or a mixture thereof. (B) were aged at 100% state of charge at 55° C. for 26 days 3. The method of claim 1, wherein the conductive filler is prior to the photographs being taken. Plastic bags 110 were carbon black, carbon fiber, graphite, a metallic nano powder, used to prevent shorting, and gas collecting pouches 120 were or a mixture of any two or more thereof. used to monitor the amount of gas generated. As evidenced by 4. The method of claim 1, wherein the concentration of the the swelling of the pouch 132, the cell without surface modi surface modification agent in the slurry is from about 0.00001 fication agent (A) generated much more gas than was gener wt % to 5 wt %. ated in the cell with the surface modification agent (B) 131. 5. The method of claim 1, wherein at least one of R. R. The pouch of cell C did not exhibit any swelling 130. 25 and R is a Substituted alkyl group that is an ethylene oxide moiety of Formula VI: What is claimed is:

1. A method of modifying a surface of an electrode active VI material, the method comprising: 30 providing a solution or a Suspension of a surface modifi "s"----- R6 cation agent; providing the electrode active material; wherein: preparing a slurry of the Solution or Suspension of the 35 m is an integer from 0 to 10; Surface modification agent, the electrode active mate n is an integer from 1 to 10; and rial, a polymeric binder, and a conductive filler, R is a substituted or unsubstituted alkyl group, a sub casting the slurry in a metallic current collector, and stituted or unsubstituted aryl group, or a carbonate drying the cast slurry; based sub group of Formula VII: 40 wherein the Surface modification agent is a silane, and the silane VII has Formula I, II, III, IV, or a mixture of any two or -(CH2). O more thereof: 45 X= O R7 O

wherein R’ is hydrogen, a substituted or unsubstituted alkyl 50 group having from 1 to 12 carbon atoms; a Sub stituted or unsubstituted alkenyl group having II from 2 to 8 carbon atoms; and q is an integer from 0 to 8. 6. The method of claim 5, wherein the surface modification 55 is a compound of Formula I; X" is Cl; R is alkyl: m is 0; and n is from 1 to 5. III 7. The method of claim 5, wherein the surface modification is a compound of Formula I; X" is Cl; R' is an ethylene oxide of Formula VI: R and Rare each alkyl; R is alkyl: m is 0; 60 and n is from 1 to 5. 8. The method of claim 5, wherein the surface modification IV is a compound of Formula I; X" is Cl; R' is an ethylene oxide of Formula VI: R and R are each methyl, ethyl, n-propyl, iso-propyl. n-butyl, sec-butyl, or tert-butyl; R is methyl or 65 ethyl: m is 0; and n is from 1 to 5. 9. The method of claim 1, wherein the surface modification agent is a compound of Formula I. US 8,292,974 B2 25 26 10. The method of claim 1, wherein the electrode active 11. The method of claim 1, wherein the electrode active material is a positive electrode active material selected from material is a negative electrode material selected from the the group consisting of spinel, olivine, carbon-coated olivine, group consisting of graphite, amorphous carbon, Li TisC2. LiFePO, Li M'M"PO, Li Ni,MnCo.Met's O.F., M-A, Li-B, Ti-CO, Aq, tin alloys, silicon alloys, ABCXO), Vanadium oxide, and mixtures of any two or 5 intermetallic compounds, lithium metal, or mixtures of any more thereof, and further wherein two or more such materials; and further wherein: M' is selected from the group consisting of V, Cr, Mg, Fe, M is selected from the group consisting of Ba, Sr, Ca,Mg, Co, and Ni; Pb, and Sn; M" is selected from group consisting of IIA, IIIA, IVA, VA, 0sxs0.5,0sys0.5,0szs0.5, 0