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United States Patent (19) 11 Patent Number: 4,505,997 Armand et al. (45) Date of Patent: Mar. 19, 1985

54 BIS PERHALOGENOACYL -OR (56) References Cited SULFONYL-IMIDES OF METALS, THER SOLD WITH PLASTIC U.S. PATENT DOCUMENTS MATERIALS AND THEIR USE TO THE 4,281,072 7/1981 Wetton et al...... 252/62.2 CONSTITUTION OF CONDUCTOR 4,303,748 12/1981 Armand et al...... 429/192 ELEMENTS FOR ELECTROCHEMICAL FOREIGN PATENT DOCUMENTS GENERATORS 26.10853 9/1977 Fed. Rep. of Germany . 75 Inventors: Michel B. Armand, Nancy, France; Fouzia El Kadiri Cherkaoui el Primary Examiner-Donald L. Walton Moursli, Sale, Morocco Attorney, Agent, or Firm-Weiser & Stapler 73 Assignees: Agence Nationale de Valorisation de (57) ABSTRACT la Recherche (ANVAR), Paris; The invention relates to novel ionic compounds which Societe Nationale Elf Aquitaine, can be incorporated in polymers whose monomer units Courbevoie, both of France include at least one hetroatom, particularly oxygen or (21) Appl. No.: 500,193 nitrogen adapted to form bonds of the donor-acceptor 22 Filed: Jun. 1, 1983 type with the cation of the ionic compound, the solid solutions obtained being utilizable to form the electro 30 Foreign Application Priority Data lyte of an electrochemical generator. These ionic com Jun. 1, 1982 (FR) France ...... 82 09540 pounds are represented by the formula 51) Int. Cl...... H01M 6/18; HO1C 4/14; CO7C 119/06 52 U.S.C...... 429/192; 252/62.2; in which : X is a , n varies from 1 to 4, Y is a CO 564/82; 564/159 or SO2 group and M is an . 58) Field of Search ...... 429/192; 252/62.2; 564/82, 159 18 Claims, 2 Drawing Figures

MICRONS 10 12 16

MPURITY

O 3OOO 2000 16OO 1200 OOO 800 6OO 400 WAVE NUMBER (cm) U.S. Patent Mar. 19, 1985 4,505,997 Fig.1.

MICRONS N 2 O Of u

2. SO C 40

O 3OOO 2OOO 18OO 16OO 14OO 20OOOO 8OO 6OO 4OO2OO WAVE NUMBER (cm)

Fig.2.

MCRONS

s 3 4. 6 ii. 10 12 - 16 25 N 2 O f S (f 2 C 1. ne

3OOO 2OOO SOO 12OOOOO 8OO 6OO 4OO WAVE NUMBER (cm) 4,505,997 1. 2 FIG. 1 is an IR spectrum of the compound BIS PERHALOGENOACYL -OR bis(trifluoromethyl acetyl)imide. SULFONYL-IMIDES OF ALKALI METALS, THEIR FIG. 2 is an IR spectrum of the compound SOLID SOLUTIONS WITH PLASTIC MATER ALS bis(trifluoromethyl-sulfonyl)imide. AND THEIR USE TO THE CONSTITUTION OF To form the compound according to the invention, CONDUCTOR ELEMENTS FOR and particularly the bis-perhalogeno-acylimides, re ELECTROCHEMICAL GENERATORS course will advantageously be had to the reaction which consists of reacting the anhydride of the formula The invention relates to a novel ionic compound having the formula MX-, in which M is a cation O derived from an alkali metal or , and X is an anion having a behaviour similar to that of a strong in which X, n and Y have the above indicated meanings, . The invention relates more particularly to ionic with a cyanate of a heavier alkali metal, preferably compounds which can be dissolved within a macromo potassium, the reaction being completed, in the case lecular material formed at least in part of one or several 5 where it is desired to obtain a bis-perhalogeno-acyli homo and/or copolymers derived from one or several mide (or a bis-halogeno-sulfonyl-imidide) of lithium or monomeric units including at least one hetereoatom, of sodium, by a ionic exchange reaction in with particularly oxygen or nitrogen, adapted to form bonds a of lithium or sodium whose anion is adapted to of the donor-acceptor type with the cation of the ionic form, with the potassium , a salt which is insoluble compound. More particularly still, the invention relates in the reaction medium, the ionic compound containing to ionic compounds of this type, which can be dissolved the lithium or sodium cation then being seperable from in at least certain of plastic materials, such as those the reaction medium. which have been described in European Patent Appli To form the bis-perhalogeno-sulfonyl-imides, re cation No. 0013199 entitled "Electrochemical genera course is advantageously had to the process which con tors for the production of current and novel materials 25 sists of reacting the anhydride of the formula: for their manufacture.' The invention also relates to the solid solutions them selves, which have thus been obtained and which, like in which X and n have the above-indicated meanings, those more particularly described in the above-said 30 with the corresponding acid and urea, preferably in the European patent application, are endowed with a suffi absence of , the mixture then being collected in cient cationic conductivity to be useful for the produc an aqueous solution. The latter is then treated with a tion of solid for-the constitution of electro tetraalkylammonium halide, particularly tetrabutylam chemical generators, preferably rechargeable. These monium bromide, to precipitate the corresponding tet solid solutions are again useful for the constitution of 35 raalkylammonium bis-perhalogeno-sulfonyl-imide. By electrochemical generator , when these elec ionic exchange reaction, between the previously ob trodes are constituted by the product of agglomeration tained compound and a reagent constituted by an alkali into a composite mass of the active material of the latter metal derivative, the compound according to the inven and, if necessary, of a compound inert to electronic tion is finally obtained. The ionic exchange may be conduction, on the one hand and of the above solid carried out particularly by bringing into play the differ solution, on the other hand. ential in a system of immiscible with It is self-evident that the solid solutions according to one another, as will be illustrated in the embodiments the invention may resort to any other type of plastic formulated below, of the bis-perhalogeno-sulfonyl material to the extent that their characteristics of recip imide of the alkali metal on the one hand, and of the rocal are sufficient for obtaining a solid solu 45 derivative resulting from the substitution in the above tion having a cationic conductivity of 10-5 said reagent of the alkali metal by the above said alkali ohms Xcm, preferably at at temperature not ex annonium group on the other hand. ceeding 130 C. The ionic compounds according to the invention The ionic compounds according to the invention may have quite satisfactory mutual dissolution qualities with be represented by the formula: 50 poly(propylene ) and even, for compounds in which the R groups are constituted by hydrocarbon chains of short length, with poly(ethylene oxide). The solid solutions obtained have a cationic conductivity in which: enabling their use as materials for electro X is a halogen, 55 chemical generators, preferably of the rechargeable in varies from 1 to 4 type, whose preferred characteristics are recalled be Y is a CO or SO2 group and low. M is alkali metal. It relates therefore to the novel materials with ionic The group X may be chlorine, bromine and iodine or, conduction, particularly cationic which are thus ob preferably, . 60 tained, mor particularly a novel polymeric solid electro M is preferably constituted by lithium or sodium. It lyte constituted at least in part by a solid solution of one may be also constituted by potassium. or several of the ionic compounds according to the The compounds obtained are named: -bis-per invention, entirely dissolved within a macro-molecular halogeno-acyl-imides, when Y is constituted by the CO material formed at least in part by a polymer, whose group and -bis-perhalogeno-sulfonyl-imides, when the 65 monomer units (of one or several types) include at least group Y is constituted by the SO2 group. one hetero-, particularly oxygen or nitrogen, The invention also relates to a process for the prepa adapted to form bonds of the donor acceptor type with ration of the above indicated compound. the cation of the ionic compound. 4,505,997 3 4. Preferably, the ratio of the number of hetero- is used less than that for which the solubility threshold derived from the one or more monomeric units of said is reached. polymer to the number of atoms of the alkali metal of It is also possible to use any known method not re said ionic compound is comprised between 4 and 30, storting to solvent, for example by dissolving in the particularly 4 and 16. It is self-evident that the propor- 5 molten polymer. tion of the ionic compound dissolved must be compati The solid electrolytes produced according to the ble with its solubility level in the selected polymer. invention, find particularly advantageous application The alkali metal is preferably lithium or sodium. for the production of both primary and secondary elec The preferred plastic materials in which the ionic trochemical generators. compounds according to the invention are placed in 10 In particular, a solid electrolyte comprising in solu solution, are homo and/or copolymers derived from tion an ionic compound of the above-indicated type, monometric units represented: may be associated with a negative , constituted either by the following formula by a material adapted to provide the alkali ion corre sponding to the metal of the ionic compound selected 15 and a positive electrode adapted to incorporate the atoms of this metal. It is possible, for example, to pro chi-h-o vide a negative electrode constituted by the same alkali R" metal in the form of an alloy, or constituted by an inter metallic compound, an insertion compound or the like. in which R" represents a atom or one of the 20 For the positive electrode, it is possible to use any mate group Ra, -CH2-O-Ra, -CH2-O-Re-Ra, rial whose crystalline structure enables the insertion of -CH2-N=(CH3)2, with Ra representing an alkyl or a alkali metals. For example may be mentioned the chal cycloalkyl radical including particularly 1 to 16, prefer cogenides which permit the diffusion of the alkali metal ably 1 to 5 carbon atoms, Re representing a polyether into their structure. It is possible again, as regard other radical of the general formula 25 examples of suitable materials for the formation of the -(CH2-CH2-O-, p having a value of 1 to 100, positive electrodes, to refer to the already mentioned particularly from 1 to 2, European patent application. or by the following formula: It is also possible to produce one of the electrodes, for example the positive one, by forming a composite from 30 the active material of the latter and from these solid solution of the ionic compound, within the same macro CH-CH molecular material. This composite can also include a R" compound inert to electronic conduction. It is also possible to resort, to constitute such electrodes and in which R" represents Ra, -Re-Ra, with Ra and Re 35 apart from the choice of the cationic compound, to the having respectively one of the above-indicated mean same methods of constitution as those described in Eu ings, ropean patent application No. 0013 199. or by the following formula: When these generators are constructed, it is observed that the novel electrolyte according to the invention has the advantage that the anion of the salt or ionic com CH2- sh pound in solution is inert with respect to the majority of electrode materials that it is possible to use. This prop O-ReaRa erty enables a large number of cycles and stable storage. In addition, this chemical inertness confers on the gen in which Ra and Re have respectively one of the above 45 erators which are thus constructed a very good resis indicated meanings, tance to thermal shock. or by the formula: Other characteristics and advantages of the poly meric solid electrolytes according to the invention will appear in the embodiments which follow it being under CH-CH 50 stood that these examples are in no way limiting. O O These examples are indicative, particularly of the N. N. chemical and/or physical properties of particular ionic R1 R2 compounds of the invention and, in relationship with in which R1 and R2 are identical or different and each 55 certain plastic electrolytes constituted with certain of represent one of the groups Re, Re-Ra with the above some of them are indicative of the values of tempera meanings, and Re can then represent also a poly-ether tures in C. for which the conductivities are equal to of the formula about 10-5) cm (Tor10-5), even to -(-CH2-CH-Op 60 10-40-cm- (Tor10-4). CH3 These measurements have been carried out in vacuum, So as to remove any trace of moisture and/or of solvent. The preparation of the polymeric solid electrolyte In all these examples, the macromolecular material is, may be carried out by the dissolving, in a solvent such 65 as the case may be, a poly-(ethylene oxide) (POE) or a as acetonitrile, or again methanol, of the polymer and of poly-(propylene oxide) of molecular weights equal or the ionic compound, then removal of the solvent, it higher than 900,000. The electrolyte has been obtained being understood that a proporation of ionic compound by dissolving 1 g of this poly-(ethylene oxide) or this 4,505,997 5 6 poly-(propylene oxide) in 35 ml of acetonitrile, then the (Bu)4N and B(C6H5)4- are removed by the organic addition of the ionic compound, to obtain atomic ratios solution (CH2Cl2). O/Li or O/Na which are indicated below. FIG. 2 provides an IR spectrum of sodium bis(tri The solution so obtained is cast on a polytetrafluor fluoromethylsulfonyl)imide. The absorption peaks in ethylene support, to a thickness of 5 mm, then stoved at the 800 cm region appear due to a trace of 60° C. for 3 hours. B(C6H5)4-. The conductivity measurements were done by the In the table which follows the electrochemical data techniques described by E. SCHOULERetal, J. Chim. are provided obtained with the foregoing compounds, Phys. 9 1309/16 (1973) and D. RAVAINE et al, J. after dissolving in a POE, in relative atomic proportions Chim. Phys. 5 (93-70 (1974). 10 (1) Preparation of Bis(trifluoromethyl acetyl)imides which are also to be seen from the table. The reaction which is used to prepare this derivative compound is: Ionic Macromoiecular conpound material O/M to 10" to 10-5 15 KN(CF3CO2) POE 12 44 42.2 Li+N(CFCO2) POE 8 3.5 46.75 LiN(CF3CO2) POE 2 64.8 47.5 Nat N(CFSO)- POE 12 60.7 45.6 solvent: acetonitrile temperature: ambient 20 These results testify as to the quite satisfactory con ductivity of the solid solutions obtained, which may The conversion of the potassium salt into a lithium with advantage be used for the manufacture of electro salt is done by ionic exchange with LiCl, within an chemical generators of the above-defined type. aqueous solution. We claim: This compound has been characterised by its IR spec 25 1. Ionic compound characterized by the formula: trum. It is represented in FIG. 1: variation of the trans mission as a function, either of the wavelength, in mi crons, or of the wave number, in cm. In the region 800–600 cm an impurity or may be a KOCN residue in which: (marked as K. N. in the Figure) is observed. 30 X is a halogen, (2) Preparation of Bis(trifluoromethylsulfonyl)imides in varies from 1 to 4, Two reactions enable the desired compound Y is a CO or SO2 group and (CFSO2)2N to be obtained. M is a alkali metal. 2. Ionic compound according to claim 1, wherein X is 1st reaction 35 fluorine. 3. Ionic compound according to claim 1, consisting of a bis(trifluoromethyl-acetyl)imide of an alkali metal. 4. Ionic compound according to claim 1, consisting of a bis(trifluoromethyl-sulfonyl)imide of an alkali metal. -- CO2 -- NH4CF3SO2 40 5. Ionic compound according to claim 1, wherein M is constituted by lithium or sodium. no solvent 6. Ionic compound according to claim 1, character ambient temperature. ized in that M is constituted by potassium. The two products obtained after the reaction are then 7. Material with ionic conduction, constituted at least dissolved in ; the addition of tetrabutylammonium 45 in part by a solid solution of one or several ionic com bromide to this solution enables the compound pounds according to anyone of claims 1, 2, 3, 4, 5 or 6, (Bu)4N+ -N(CF3SO2)2 to be precipitated. entirely dissolved within a macromolecular material 2nd reaction formed at least in part by a polymer whose monomer units include at least one hetero-atom, adapted to form 50 bonds of the donor-acceptor type with a cation of the ionic compound. - 8. Material with ionic conduction, according to claim 7, wherein the hetero-atom is oxygen or nitrogen. solvent: dichloromethane 9. Material with ionic conduction, constituted at least temperature: ambient. 55 in part by a solid solution of one or several ionic com pounds according to anyone of claims 1, 2, 3, 4, 5 or 6, After removal of the solvent (CH2Cl2), the products entirely dissolved within poly(ethylene oxide) or poly(- of the reaction are dissolved in water. Tetrabutylam propylene oxide). monium bromide added to this solution results in the 10. Material with ionic conduction according to precipitation of (Bu)4N+-N(CFSO2)2. 60 claim 7, wherein the ratio of the number of hetero The corresponding sodium salt is obtained by the atoms derived from the monomer units of said macro following ion exchange: molecular material to the number of atoms of alkali metal of said ionic compound is comprised between 4 and 30. solvents: H2O and CH2Cl2. 65 11. Material with ionic conduction according to The hydrophilic character of the Na+ and claim 7, wherein the ratio of the number of hetero (CF3SO2)2N ion enables migration in the aqueous atoms derived from the monomer units of said macro phase. On the other hand, the hydrophilic ions molecular material to the number of atoms of alkali 4,505,997 7 8 metal of said ionic compound is comprised between 4 15. Electrochemical generator, wherein its electro and 16. lyte is constituted by the material according to claim 9, 12. Material with ionic conduction according to and the negative electrode associated with it is consti claim 9, wherein the ratio of the number of hetero tuted by a material adapted to supply the alkali ion corresponding to the metal of the selected ionic com atoms derived from the monomer units of poly(ethylene pound, and the positive electrode which is associated oxide) or poly(propylene oxide) to the number of atoms with it is adapted to incorporate the atoms of this metal. of alkali metal of said ionic compound is comprised 16. An electrode structure which comprises a solid between 4 and 30. solution of an ionic compound according to claim 1 13. Material with ionic conduction according to 10 dissolved within a macromolecular material formed at claim 9, wherein the ratio of the number of hetero least in part by a polymer whose monomer units include atoms derived from the monomer units of poly(ethylene at least one hetero-atom, adapted to form bonds of the oxide) or poly(propylene oxide) to the number of atoms donor-acceptor type with a cation of the ionic com of alkali metal of said ionic compound is comprised pound. between 4 and 16. 15 17. The electrode structure of claim 16 wherein said electrode structure is a positive electrode and said struc 14. Electrochemical generator, wherein its electro ture includes alkali metals. lyte is constituted by the material according to claim 7 18. The electrode structure of claim 16 wherein said and the negative electrode associated with it is consti electrode structure is a negative electrode and said tuted by a material adapted to supply the alkali ion structure includes a material adapted to supply the al corresponding to the metal of the selected ionic com kaliion corresponding to the metal of the selected ionic pound, and the positive electrode which is associated compound. with it is adapted to incorporate the atoms of this metal. e sk k ck ck

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