MXPA00010034A - Ionomers and ionically conductive compositions - Google Patents

Abstract

Disclosed are ionomers comprising functionalized polyolefins having fluoroalkyl sulfonate pendant groups and ionically conductive compositions formed therefrom by the addition of solvents.

Description

IONOMERS AND IONICALLY CONDUCTIVE COMPOSITIONS FIELD OF THE INVENTION This invention relates to ionomers comprising functionalized polyolefins having suspended groups of fluoroalkyl sulfonate and to ionically conductive compositions formed therefrom by the addition of solvents thereto. The ionically conductive compositions of the invention are useful in batteries, fuel cells, electrolysis cells, ion exchange membranes, sensors, electromechanical capacitors and modified electrodes.

TECHNICAL BACKGROUND OF THE INVENTION It has been known for a long time in the art that forming membranes and gels that are ionically driven from organic polymers contain ionic suspended groups. Such polymers are known _0 as ionomers. Particularly well-known ionomeric membranes in commercial use in general are Nafion® Membranes available from E.I. du Pont de Nemours and Company. Nafion "is formed by the copolymerization of tetrafluoroethylene (TFE) with _5 perfluoro (3, 6-dioxa- -methyl-7-octensulfonyl fluoride), Ref: 12265 as described in United States Patent 3,28, 875. Also known are TFE copolymers with per fluoro (3-oxa-4-pentensulfonyl fluoride), as described in U.S. Patent, 358.5.5. The copolymers thus formed are converted to the ionomeric form by hydrolysis, typically by exposure to an appropriate aqueous base, as described in U.S. Patent 3,282,875. Lithium, sodium and potassium are all well known in the art as suitable cations for the ionomers mentioned in the above. In the polymers mentioned in the above, fluorine atoms provide more than one benefit. The fluorine groups in the carbons close to the sulfonyl group in the suspended side chain provide the electronegativity giving the cation sufficiently labile to provide high ionic conductivity. The replacement of those fluorine atoms with hydrogen results in a considerable reduction in ionic mobility and consequent loss of conductivity. The rest of the fluorine atoms produce the chemical and thermal stability to the polymer normally associated with fluorinated polymers. This has proven to be of considerable value in such applications as the well-known "chloralkyl" processes. Nevertheless, Highly fluorinated polymers also have disadvantages where there is less need for high chemical and thermal stability. Fluorinated monomers are more expensive than their olefin counterparts, require higher processing temperatures, and often require expensive corrosion resistant processing equipment. In addition, it is difficult to form solutions and dispersions of fluoropolymers. Additionally, it is difficult to form strong adhesive bonds with fluoropolymers. In materials used in electrochemical cells, for example, it may be advantageous to have better processability at the same cost for chemical and thermal stability. Thus, there is an incentive to develop ionomers with highly labile cations that have non-fluorinated polymer backbones. Numerous publications describe polyethers with either ionic species nearby in the polymer or in combination with ionic salts. The conductivities are in the range of 10"5" / cm and smaller Le Nest et al., Polymer Communications ^ 8, 303 (1987) describe a composition of polyether glycol oligomers linked by hydrolyzed portions of phosphate and thiophosphate for the ionomer of related lithium In combination with propylene carbonate, conductivity is carried out in the range of 1-10x10"'S / cm. An analysis of the related technique was found in Fauteux et al., Electrochimica Acta 0_, 2185 (1995), Benrabah et al, Electrochimica Acta, 40, 2259 (1995) describe crosslinked polyethers by lithium oxytetrafluorosulphonates and derivatives.Aprotic solvents are not incorporated.They are carried out with the addition of the lithium salt conductivity of <10 ~ 4 S / cm. Armand et al., U.S. Patent 5,627,292 describe copolymers formed from fluoroethoxysul fonory fluorides or cyclic ethers having fluoroethoxysulfonyl fluoride groups with polyethylene oxide, acrylonitrile, pyridine and other monomers. Lithium sulfonate ionomers are formed. No aprotic solvents are incorporated. The conductivity was < 10"4 S / cm Narang et al., U.S. Patent 5,633,098 disclose acrylate copolymers having a functionalized polyolefin skeleton and pendant groups containing tetrafluoroethoxy-lithium sulphonate groups The comonomers containing the sulfonate groups are present in molar ratios of 50-100% The compositions are described as comprising the polymer and a mixture of solvents consisting of propylene carbonate, carbonate ethylene, and dimethoxyethane. The ionic conductivity of these compositions is in the range of 10 ~ 4-10 ~ 3 S / cm. Brookhart et al., WO 9623010A_, describe a copolymer formed from ethene and fluoride 5 of 1, 1, 2,2-tetrafluoro-2- [(1, 1, 2,2, 3, 3, _,. octafluoro-9-decenyl) oxy] ethanesulfonyl via a catalyzed reaction employing transition metal complexes with diin. The polymer thus formed comprises a polyethylene skeleton having randomly suspended groups distributed from 1, 1, 2, 2-tetrafluoro-2- [(1, 1, 2, 2, 3, 3, _,. Octafluoro fluoride. - (mainly) octoxy] -ethanesulfonyl, as well as alkyl branches.

BRIEF DESCRIPTION OF THE INVENTION This invention provides for an ionomer comprising a skeleton and suspended groups, the skeleton consists essentially of methylene units and the suspended groups comprise ionic radicals of the formula _0 -R "-Rf-CF2CF2-? 02- X- (S02Rf) a- M * where M * is a monovalent metal cation; the groups Rf are independently selected from the group that consists of linear per-fluoroalkylene radicals or branched, perfluoroalkyl radicals containing 0 or Cl, and perfluoroaryl radicals; R is hydrocarbyl where n = 0 or 1; a = 0-2; and X = 0, N or C; the ionic radicals are further limited because a = 0 when X = N, and a = 2 when X = C. This invention further provides for an ionically conductive composition comprising the ionomer described above and a liquid saturated therewith. This invention also discloses a process for forming an ionomer, the process comprising contacting a polyolefin comprising a skeleton and suspended groups, the backbone consists essentially of methylene and methine units and the suspended groups comprise ionic radicals of the formula where X is F or Cl, Rf is a linear or branched perfluoroalkylene, per fluoroalkylene containing O or Cl, or per fluoroaryl radical, and R is hydrocarbyl where n = 0 or 1, with a solution of an alkali metal base. In addition, a process for forming a conductive composition is described, the process comprising contacting the above ionomer with a liquid.

Also included therein is an electrode comprising at least a single electrode of active material, the ionomer described herein is mixed therewith, and a liquid saturated therewithin. Further, an electrochemical cell comprising a positive electrode, a negative electrode, a separator disposed between the positive and negative electrodes, and means for contacting the cell with an external source or charge, wherein at least one of the group consisting of of the separator, the cathode and the anode, comprises the above ionomer.

DETAILED DESCRIPTION In a preferred embodiment of the polyolefin ionomer of the invention, the backbone consists essentially of olefinic radicals of which 1- _0 mol% have suspended groups in the form of a radical of the formula M * "S03-CF2CF2-0- [(CFR1CF2) x-Oy]" - (CH2) Z- (I) Where M * is an alkali metal cation, Ri is perfluoroalkyl or fluorine, x = 0, 1, 2 or 3, y = 0 or 1, n = 0, 1, 2 or 3, and z is an integer in the range from 2 to 6. Most preferably M * is a lithium cation, Ri is fluorine, x = 1, y = 0, n = 1 or 2, z = 4. The olefinic radicals that make the backbone of the polyolefin ionomer of the invention are substantially unsubstituted except that 1-20 mole% of the olefinic moieties of the backbone in a preferred embodiment of the invention have a group suspended in the radical form (I ). In a more preferred embodiment, 2-10 mole% of the olefinic radicals of the backbone have a group suspended in the form of the radical (I). As is known in the art, the degree and type of branching in a polyolefin depends on the monomers used in the polymerization and the method by which the polymerization is carried out. Ethylene polymerized by various catalytic methods demonstrate short chain branches at a frequency of < 1 to about 150 per 1000 methylene groups in the backbone depending on the catalyst used and reaction conditions. The short chain branches thus formed are mainly methyl or ethyl groups. When the polymerized olefinic monomer is greater than ethylene, the number of branches increases considerably, since there is then at least one inherent side chain in each monomer unit. It was found in practice that the chain branching has a significant effect on the ionic conductivity of the conductive compositions of the present invention. To achieve the highest conductivity, the branching frequency of 5-90 methyl branches per 1000 methylenes is preferred when the ionomer of the invention is produced from polymers synthesized by the catalytic routes described herein. A greater degree of branching appears to be tolerable when the ionomer is made by the graft polymer route described in the following. Preferred ionomers of the invention are conveniently produced according to methods known in the art, by contacting a nonionic sulfonyl halide precursor with a solution of an alkali metal hydroxide thereby hydrolyzing the polymer to the alkali metal salt. . It was found in the practice of the invention, that the acid form of the ionomer of the invention is more easily produced by first subjecting the nonionic precursor to a solution of an alkali metal hydroxide followed by ion exchange with an aqueous acid. Others Monovalent metals, such as copper or silver, can be exchanged for the alkali metal ion by ion exchange methods known in the art. Preferred precursor polymers for the practice of the invention can be formed by the copolymerization of one or more olefins, preferably ethylene, and a preferably substituted olefin comonomer of the formula FSO2-CF2CF2-O- [(CFRjCFz), -O?] "- (CH2) Z-CH = CH2 where Ri is perfluoroalkyl or fluorine, x = 0, 1, 2 or 3, y = 0 or 1, n = 0, 1, 2 or 3 and z is an integer in the range of 2 to 6. Most preferably, Ri is fluorine, x = l, y = 0, n = 1 or 2, and z = 4. Such copolymerizations are known in the art, and are easily realizable using catalytic methods such as that in Brookhart et al., WO9623010A2, and as shows below. Diimine transition metal complexes as described by Brookhart, and as exemplified below, catalysts are preferred to form nonionic precursor polymers preferred by the process of the invention. In the polymer thus formed, the skeleton consists essentially of olefinic radicals of which l-20 mol%, preferably -10 mol%, have suspended groups of l, l, 2,2-tetrafluoro-2- [(1, l, 2,2,3,3,4-, 4-octafluoro- (mainly) octoxy] ethanesulfonyl, the polymer has less than 150, preferably 5-90, alkyl branches, mainly methyl and ethyl, per 1000 methylenes. has a determinant effect on the number of chain branches Other catalysts suitable for the practice of the invention include metallocene and Ziegler-Natta catalysts The most preferred catalysts are the nickel diimine catalysts represented by structures B and D in the Table 2 below in combination with PMAO.These catalysts offer a desirable combination of good proportions of comonomer incorporation, branching levels in the preferred range, all with high polymer yield. nickel-di-amino alylating agents, it has been found in the practice of the invention that a greater degree of polymeric branching results from the use of large volume catalysts. The less bulky catalysts are associated < -on greater incorporation of the substituted olefinic comonomer containing sulfonyl. The degree of branching made in metallocene-catalyzed copolymerizations (see, for example, Yang et al, J. Am. Chem. Soc. 116, pp. 10015ff, 1994) of the preferred comonomers of the invention is generally low with conductivity inferior concomitant. However, the use of a thermonomer, preferably an olefin with three or more carbons in the chain, in combination with a metallocene or Ziegler-Natta catalyst can increase the degree of branching in the resulting polymer with higher resulting ionic conductivity.

Other means are also suitable for forming the ionomers of the invention. These include forming the ic-c-ero of the present invention by grafting a substantially unsubstituted polyolefin, preferably polyethylene, a radical of the formula FSO2-CF2CF2-O- [(CFRjCFüíx-Oyln- (CH2) _- Where Ri is perfluoroalkyl or fluorine, x = 0, 1, 2 or 3, y = 0 or 1, n = 0, 1,. or and z is an integer in the range of 2 to 6, is grafted to polyethylene. Preferably, R is fluorine, x = 1, y = 0, n = 1, and z = 2.

Various methods of grafting polyolefins are known in the art. A method found to be adequate is exemplified in the following. In another embodiment a polymer has a backbone consisting essentially of olefinic radicals of which l-20% by mole has groups suspended in the form of a radical of the formula XS02-CF2CF2-Rf-Rn- wherein X is F or Cl, Rf is a linear or branched perfluoroalkylene, per fluoroalkylene containing O or Cl, or per fluoroaryl radical, and R is hydrocarbyl where n = 0 or 1, are reacted with Rf '-S02-N (Na) SiMe3 according to the methods described by Desmarteau, in J. Fluorine Chem., 5 ^, pp. 7ff, 1991. The resulting polymer has a backbone of substantially unsubstituted olefin radicals of which 1-0.0 mol% has suspended groups in the form of a radical of the formula -Rn-Rf-CF2CF2-S02-N "S02R '_ Na * where the groups Rf and Rf 'are radicals per fluoroalkylene, per fluoroalkylene containing 0 or Cl, or per fluoroaryl linear or branched, and not all need to be the same, R is hydrocarbyl where n = 0 or 1. The ion can be replaced sodium, for example, lithium ion by simple cation exchange procedures known in the art. In yet another embodiment, a polymer having a skeleton consisting essentially of olefinic radicals of which 1-20% by mol have suspended groups in the form of a radical of the formula wherein X is F or Cl, Rf is a linear or branched per-fluoroalkylene, a perfluoroalkylene containing 0 or Cl, or a per-fluoroaryl radical, and R is hydrocarbyl where n = 0 or 1, is reacted with (Rf '-S02) 2-C (MgBr) 2 prepared by the method of Seppelt, Inorg. Chem. 27, pp. 2135 ff, 1988, combining in THF solution and stirring at room temperature overnight, followed by removal of solvent and treatment with aqueous HCl for several hours. The solution is then filtered, washed with water, and then treated with an alkali metal base solution. The resulting polymer has a substantially unsubstituted olefin radical backbone where from 1-20 mol% has suspended groups in the form of a radical of the formula -R "-Rf-CF2CF2-S02-C" (? 02R 'f) 2 where M * is an alkali metal, the groups Rf and Rf 'are linear or branched perfluoroalkylene radicals, per fluoroalkylene containing O or Cl, or perfluoroalkyl radical, and do not all need to be the same, R is hydrocarbyl where n = 0 or 1. It has been found in the practice of the invention that the degree of incorporation of comonomer has a deeply non-linear effect on the conductivity of the conductive compositions of the invention. For comonomer concentrations below about 2 mole%, conductivity ranges from 0 to about 10"5? / Cm, almost independent of the degree of branching or the liquid used.Conductive compositions exhibiting conductivity of 10" 5 S / cm or less are of relatively limited utility. In incorporation of comonomer of approximately 2-3 mole%, the ionic conductivity increases considerably, exhibiting strong branching dependence and the choice of liquids used to form the conductive composition. In the range of about 3-10 mol% conductivities in the range of 10"5 to 10" 2 S / cm are achieved while observing a moderate dependence of comonomer concentration. Little additional benefit is obtained at comonomer concentrations of about 10 mole% versus about 6-7 mole%. It is believed by the inventors that one reason for this "decrease back" effect is that the catalysts required to achieve higher comonomer incorporation in the polymer also produces polymer with less branching so that the two effects are somewhat self-cancelled. further, conductivity was observed well above 10"5 S / cm in conductive compositions of the invention where propylene carbonate is employed as the liquid, in concentrations of comonomer in the polymer of less than 10% in moles, in severe contrast with the teachings of the art. In a preferred embodiment of the present invention, the ionic functionality is present in the ionomer, preferably at a concentration of 1-10 mol%, more preferably 3-7 mol%. While there is no limit to the conformation or proportions of an article formed from the ionomers of the invention, thin films or membranes are of particular utility. The ionomers of the invention are not completely thermoplastic and are not easily processable as the nonionic precursor polymers from which they are derived. In this way it was found convenient to form membranes of the precursor polymers by methods generally known in the art and as described hereinbelow. It is particularly convenient to extrude film using a screw extruder and a flat die. Alternatively, the films can be melt compressed. And, in a further alternative, the films can be emptied of solutions or dispersions of the precursor polymers by pouring into a substrate and coagulating.

No particular method is preferred over another, and the specific method will be chosen according to the needs of the doctor. The ionomers of the present invention exhibit ionic conductivity at room temperature of about 10"7-10" 6 S / cm when dried. However, it was found in the practice of the invention that various liquids when saturated in the ionomer of the invention improve the conductivity by magnitude arrangements. In this way it has been found desirable to achieve the most useful embodiments of the present invention to form conductive compositions wherein the liquids are saturated in the ionomer of the invention. The liquid used will be dictated by the application. In general terms, it has been found in the practice of the invention that the conductivity of the liquid containing ionomer increases with the uptake of increase in% by weight, dielectric constant of increase in liquid, while the conductivity has been observed to decrease with the viscosity of increase and molecular size of increase of the liquid used. In this way, a highly basic solvent of low viscosity and small molecular size but low dielectric constant can provide Higher conductivity in a given membrane than a larger, more viscous, less basic solvent of very high dielectric constant. Naturally, other considerations are also a game. For example, excessive solubility of the ionomer in the liquid may be undesirable. Or, the liquid can be electrochemically unstable in the desired use. A particularly preferred embodiment comprises the lithium ionomer combined with aprotic solvents, preferably organic carbonates, which are useful in lithium batteries. The preferred electrode of the invention comprises a mixture of one or more active electrode materials in particulate form, the ionomer of the invention, at least one conductive electron additive, and at least one organic carbonate. Examples of useful active anode materials include, but are not limited to, carbon (graphite, coke, mesocarbons, polyacenes and the like) and carbon intercalated with lithium, lithium metal nitrides such as Li2.6Coo. N, tin oxide, glass based, lithium metal and lithium alloys, such as lithium alloys with aluminum, tin, magnesium, silicon, tin, manganese, iron and zinc. Lithium intercalation anodes employing carbon are used.

Useful active cathode materials include, but are not limited to, transition metal oxides and sulfides, lithium transition metal oxides and sulfides, and organic sulfur compounds. Examples of such are cobalt oxides, manganese oxides, molybdenum oxides, vanadium oxides, titanium sulphides, molybdenum and niobium, lithiated oxides such as lithium and manganese oxides of spinel i? + XMn2-x? 4, oxides of lithium and manganese spinel doped with chromium LixCryMn204, LiCo02, LiNi02, LiNixC?! _ x02 where x is 0 <; x < 1, with a preferred range of 0.5 < x < 0.95, LiCoVOi, and mixtures thereof. LiNixC ??-x02 is preferred. A highly preferred electron conductive aid is carbon black, preferably Super P carbon black, available from MMM S.A. Coal, Brussels, Belgium, in the concentration range of 1-10%. Preferably, the volume fraction of the lithium ionomer in the finished electrode is between 4 and 40%. The electrode of the invention can be conveniently made by dissolving all the polymeric components in a common solvent and mixing together with the carbon black particles and active electrode particles. For cathodes the preferred active electrode material is LiNixCol-x02 where 0 < x < 1, while for the anodes the preferred active electrode material is graphitized mesocarbon microbeads. For example, a preferred lithium battery electrode of the invention can be manufactured by dissolving the ionomer of the invention in a mixture of acetone and dimethylformamide, followed by the addition of particles of active electrode material and carbon black, followed by deposition of a film on a substrate and a dryer. The resulting preferred electrode will comprise active electrode material, conductive carbon black, and ionomer of the invention, wherein, preferably, the weight ratio of the ionomer to active electrode material is between 0.05 and 0.8 and the weight ratio of the carbon black The active electrode material is between 0.01 and 0.2. More preferably the weight ratio of the ionomer to active electrode material is between 0.1 and 0.25 and the weight ratio of carbon black to active electrode material is between 0.02 and 0.1. This electrode can then be emptied from the solution into a suitable support such as a glass plate or metal tap sheet, and formed into a film using techniques well known in the art. The electrode film thus produced can then be incorporated into a cellular structure Multilayer electrochemistry by lamination, as described hereinbelow. It may be desirable to incorporate such adjuvants into the spacer composition of the invention as they may be useful for such purposes by improving the binding of the components thereof, or by providing improved structural integrity of an article manufactured therefrom. A particularly preferred additional material is α02 which can be incorporated by simply dispersing the particles thereof in the same solution from which the separator is formed, as described herein above. Silica particles are preferred of an average particle size of less than 1.0 microns, silica is present in a mixture of up to 50% by weight of the total. In an alternative process, the dispersion of the optional active carbon black and electrode material and other adjuvants can first be cast on a surface followed by the addition of the ionomer of the invention in organic carbonate solution. The invention is further described in the following specific embodiments.

EXAMPLES The nonionic precursor polymers I-XIV described hereinbelow, were formed by copolymerization of ethylene with a comonomer of the formula FS02-CF2CF2-0- (CF2) "(CH2) 4CH = CH2 where n = 2 or 4. The solvent employed was toluene, except in the case of the synthesis of Polymer XI where it was dichloromethane. With reference to Table 1, the polymers I-X and XIV synthesized by combining in a Schlenk flask in a dry box purged with nitrogen, the indicated amounts of the catalysts, comonomers and solvent indicated. The structure of the designated catalyst is given in Table 2. The mixture was then removed from the dry box and placed under 1 atmosphere of ethylene. The mixture was purged with ethylene for 15 minutes while cooling by immersion in an ice-water bath. 2.2 ml of a 7.1% polymethylalumoxane (PMAO) solution in toluene (4.4 ml for polymers VII and XIV) were then introduced at the start of the reaction, and the mixture was stirred for the indicated time. In the term of time indicated, 5 ml of methanol was slowly added to the reaction mixture, after which the mixture was decanted into 150 ml of methanol, followed by the addition of 1.5 ml of concentrated aqueous HCl. The resulting mixture was stirred for approximately 30 minutes. The resulting white solid polymer was filtered, washed with six aliquots of 20 ml of methanol, and dried in vacuo. The polymer XI was synthesized by combining the indicated amounts of the indicated catalyst, comonomer and dichloromethane solvent in a Schlenk flask. The reaction was started by placing the mixture under 1 atmosphere of ethylene at room temperature; no PMAO was added. The reaction was carried out for 4.260 minutes under stirring. The resulting polymer was an oily liquid. The reaction was filtered. 350 ml of methanol was added to the filtrate with stirring. A precipitate of oil in 100 ml of dichloromethane was isolated and re-dissolved followed by the addition of 350 ml of methanol. A light yellow oil product was isolated and dried in va cuo. The material thus produced exhibited a glass transition temperature of -66 ° C and no melting point. The polymers XII and XIII were produced by combining a Schlenk flask in a dry box with the indicated amounts of the catalyst, comonomer and solvent indicated. The mixture was placed under 1 atmosphere of ethylene and purged with ethylene for 15 minutes. 10 ml of a 7.1% PMAO solution in toluene was added at the beginning of the reaction, which continues under stirring for the indicated time at the indicated temperature. 350 ml of methane was slowly added to the reaction mixture followed by 5 ml of concentrated HCl. The white solid polymer was filtered, washed with methanol and dried in vacuo. Molecular weight was determined by gel permeation chromatography using polyethylene standards. The melting points were determined using a DuPont Differential Scanning Calorimeter model 912 by cooling to -100 ° C, then heated to 10 ° C / minute at 150 ° C. In the examples described herein below, the polymers were designated according to Roman numerals I-XVII. The catalysts used are designated in Table 1 by a letter designation corresponding to the catalysts listed in Table 2. The% comonomer in the polymer was determined by a combination of proton and 13C nuclear magnetic resonance.

TABLE 2: Catalysts used in the Synthesis of Polymers I-XIV DESIGNATION OF THE CATALYST Catalyst Pd (CH2) 3C (0) OCH3 (. {2,6- [CH (CH3) 2] 2 6H3.} 2DAB (CH3) 2> SbF6 rac-ethyl ester 1-eribi (indenyl) zirconium (IV ) The nonionic precursor polymers XV and XVI discussed below were formed by copolymerization of propylene with a comonomer of the structure.

FS02-CF2CF2-0- (CF2) 2 (CH2) 4CH = CH2 The solvent used was toluene. Polymer XV was synthesized by combining in a Schlenk flask in a dry box 2.3 mg (0.0055 mmol) of rac-ethylenebis (indenyl) zirconium dichloride catalyst (IV), 2.72 g (7.11 mmol) of CH2 = CH (CH2) 4 (CF2) 20 (CF2) 2? 02F and 25 ml of toluene. This is placed under 0.210921 kg / cm2 (3 psig) of propylene in a water bath with ice and purged with propylene for 10 minutes. PMAO (7. ml of 7.1 wt% toluene solution) was added to the mixture. After stirring under 0.210921 kg / cm2 (3 psig) of propylene at 0 ° C for 1 hour, methanol (150 ml) was slowly added to the reaction mixture followed by 5 ml of concentrated HCl. The white solid polymer was filtered, washed with methanol and dried in vacuo. Copolymer (1.35 g) was obtained. The polymer was isotactic based on 13 C NMR. 1H-NMR (TCE-d2) indicates a comonomer incorporation of 2.9 mol%. The copolymer has a melting point of 133 ° C by differential scanning calorimetry. Gel Permeation Chromatography (TCB, 135 ° C, Polyethylene Standard): Mp = 23,200; Mn = ll, 000; Mp / Mn = 2.1. Polymer XVI was synthesized by combining in a Schlenk flask in a dry box 2.3 mg (0.0055 mmol) of rac-ethylenebis (indenyl) zirconium dichloride catalyst (IV), 5.5 g (0.0144 moles) of CH2 = CH (CH2) 4 (CF2) 20 (CF2) 2? 02F and 25 ml of toluene. This is placed under 0.2109_1 kg / cm2 (3 psig) of propylene in an ice water bath and purged with propylene for 10 minutes. PMAO (4.0 ml of 12.9% by weight toluene solution) was added to the mixture. After stirring under 0.210921 kg / cm2 (3 psig) of propylene at 0 ° C ffiy ... __¿ & for 2 hours, methanol (5 ml) was slowly added to the reaction mixture. The mixture was then poured into 150 ml of methanol, followed by 5 ml of concentrated HCl. After stirring at room temperature for 20 minutes, the white solid polymer was filtered, washed with methanol and dried in vacuo. Copolymer (4.6 g) was obtained. The polymer was isotactic based on 13 C NMR. 1H-NMR (TCE-d2) indicates a comonomer incorporation of 3.8% by moles. The copolymer has a point of fusion of 124 ° C by differential scanning calorimetry. Gel Permeation Chromatography (TCB, 135 ° C, Polyethylene Standard): Mp = 39,200; Mn = 20,900; Mp / Mn = l .9. The nonionic precursor polymer XVII described in the present below was formed by gratification of CH2 = CH (CF2) 20 (CF2) 2S02F in high polyethylene density. Polymer XVII was synthesized by combining a solution of 13.03 g of high density polyethylene (Aldrich, Mp = 125,000) in 100 ml of o-dichlorobenzene a 125 ° C, with 10.15 g of CH2 = CH (CF2) 20 (CF2) 2S02F under nitrogen followed by slow addition of a solution of tert-butyl peroxide cyclobenzene (1.23 g of tBuOOtBu in 20 ml of o-dichlorobenzene) . The addition was completed in 7 hours. The solution was then left to rest during the night. The solution was emptied in 500 ml of methanol, and mixed in a laboratory mixer followed by filtration, a total of four times the steps of methanol dissolution, mixing and filtration being performed. The solid polymer was then washed with methanol three times and dried in vacuo. White polymer was obtained (21.3 g). Based on NMR 'H, the mole percentage of the comonomer incorporation was 5.4%. Based on the branching frequency of NMR was 7 Me / 1000CH2, GPC (TCB, 135 ° C, PE standard): Mp = 65,700; Mn = 4.8_0; P / D = 15.3. The copolymer has a melting point of 118 ° C based on DSC. The films designated F1-F16, F19, F21-F23 of the invention were made of the polymers of the invention. Polymer VI was found to be excessively brittle to allow for other handling, probably due to the low molecular weight, and could not be manufactured in a free film position. Polymer XI was an oil that could not be manufactured in a film free of position at room temperature. All other polymers herein designated Polymer I-V and Polymer VII-X, and XII-XVII were made into films. The films compressed by fusion, designated in Table 3 as "MP", in the range of 3.75 cm x 3.75 cm to 7.5 cm x 7.5 cm were formed by placing approximately 0.25-5.0 g of the dried polymer between two sheets of Kapton® Polyimide Film available from DuPont, Wilmington, DE, and inserted between the platens of a hydraulic press (model P218C, Pasadena Hydraulic Industries, City of Industry, CA) equipped with Omron Electronics Inc. (Schaumburg, IL) E5CS temperature controllers. The polymer was preheated for two minutes, followed by compression for two minutes, followed by cooling under pressure. The resulting films vary in thickness from approximately 63 to 127 misters. The specific temperatures and pressures employed are given in Table 3. The solution of cast films, designated in Table 3 as "soln", was prepared by dissolving 0.25-5.0 g of polymer in the indicated solvent by heating the solvent until it dissolves the polymer, followed by emptying in a glass drain tray with 2.5 cm x 2.5 cm wells. The solvent was evaporated at room temperature by dropping polymer films ranging in thickness from about 25-127 microns.

EXAMPLES 1-22 Each of the film samples F1-F16, F19, F21-F23 described in Table 3, plus two oil aliquots of polymer XI, was hydrolysed by treatment with a saturated solution of LiOH in methanol: water 1 : 1, followed by a rinse in methanol: water 1: 1 at room temperature, and then heating in a fresh metal / water 1: 1 mixture. Samples or specimens were then dried, except where otherwise specified in a Model 1430 vacuum oven available from VWR Scientific, West Chester, PA, at a pressure of approximately 220 torr. Table 4 provides the duration and temperature of film exposure to the LiOH solution, the duration of rinsing at room temperature, the temperature and duration of the hot rinse, and the temperature and duration of the hydrolysed film drying.

Table 4. Hydrolysis / Lithiation of Polymers EXAMPLE 23 A sample of 4.43 g of Polymer XIV in the form of a polymer crumb as it is polymerized, formed as described in Example XIV, was subjected to hydrolysis by immersion for two hours in an excess of a saturated solution of LiOH in a 1: 1 water / methanol mixture preheated to 70 ° C, followed by heating at 75 ° C and maintained for an additional two hours, followed in turn by cooling to room temperature and kept for 12 hours, and followed by heating to 75 ° C again, and was maintained for 4 hours. The resulting hydrolyzed polymer was then rinsed for 12 hours at room temperature in a 1: 1 water / methanol mixture, followed by a 4 hour rinse at 80 ° C in a fresh 1: 1 water / methanol mixture followed by rinsing for 12 hours at room temperature in a water / methanol 1: 1 mixture. The hydrolyzed polymer was then dissolved in THF and poured into a film by casting in a glass dish, followed by evaporation of the THF, and separation of the film from the dish. The hydrolyzed film thus formed was designated in the present below as shown in S20.

EXAMPLE 24 0.2817 g of the lithiated polymer sample S19 prepared as described hereinabove was placed in 10 ml of THF and heated gently until dissolved. 0.056 g of Cabot Cab-o-sil * TS530 was added and stirred until dispersed. The dispersion was emptied in a round Petri dish of Teflon * PFA, 50 mm in diameter, and the solvent was allowed to evaporate to form the hydrolyzed film designated hereinafter as sample S24.

EXAMPLES 25-181 The dried hydrolyzed films of Examples l-24, Sl-? 24, were transferred to a sealed container while still heated and transported to a glove box having a positive pressure of dry nitrogen applied thereto, where the membrane was removed from the sealed container and allowed to reach room temperature. Still in the glove box, the membrane is then cut into several sections of 1.0 cm by 1.5 cm in size. Typically, the samples or specimens as they are prepared are then heated to 100 ° C under vacuum for 24-48 hours.

A cooled 1.0 cm by 1.5 cm membrane sample is then soaked in an excess of one or more liquids in a sealed glass vial for 24 hours at room temperature. The liquids used are all commercially available, and were used as they were received. Following the immersion, the membrane sample was removed from the liquid bath, dried with a paper towel to remove excess liquid and tested. The ionic conductivity was determined using the so-called four-point probe technique described in an article entitled "Proton Conductivity of Nafion® 117 As Measured by a Four-Electrode AC Impendance Method" by Y. Soné et al., J. Electroche. Soc., 143, 1254 (1996). The method as described is applied to aqueous electrolyte membranes. The method was modified for purposes of obtaining the measurements presented herein for non-aqueous solvents by placing the described apparatus in a sealed glove box, purged with dry nitrogen to minimize any exposure to water. The method was also modified by replacing the parallel linear probes by traversing the total width of the test sample for the probes of the point used in the published method.

A film of 1.0 cm by 1.5 cm was dried and placed in the conductimetric cell. The impedance of the cell was determined over the range of 10 Hz to 100,000 Hz, and the value with zero phase angle in the highest frequency range (usually 500-5000 Hz) was attributed to the resistance of the volumetric sample in Ohms . The raw strength value was then converted to conductivity, in S / cm, using the tub constant and the swollen film thickness with liquid. The following abbreviations have been used: DEC diethyl carbonate DEE diethoxy methane DMC dimethyl carbonate DME 1,2-dimethoxyethane DMF N, N-dimethylformamide DMSO dimethyl sulfoxide EC ethylene carbonate (1,3-dioxolan-2-one) GBL? -butyrolactone MA methyl acetate MeOH methanol MG methyl glycolate NMF N-methylformamide NMP N-methylpyrrolidone PC propylene carbonate PEG poly (ethylene glycol) THF tetrahydrofuran EXAMPLES 25-138 In the conductivity tests thus performed, wherein the hydrolyzed films of the invention, Sl-S24, were combined with the indicated liquids to form conductive compositions of the invention, as described in the compositions shown in Table 5 were found to exhibit ionic conductivity at room temperature greater than 10"5 S / cm.

Table 5 Examples 25-138: Ionically Conductive Compositions Formed by Combination of Liquefied and Film that Exhibited Conductivity Greater than 10 S / cm Hydrolyzed Film Sample Saturated Liquids? 2 PC / DME; EC / DME S4 PC / DME; EC / DME; PC; DMSO; DMF S9 PC; PC / DMC; PC / DME; EC / PC; EC / DMC; EC / DME S10 PC; EC / DME; DMSO; DMC; THF; PC / DME; PC / DMSO, PC / DMC Sil PC / DEC; EC / DMC; EC / PC; NMF; DME; PC; DME; EC / PC / DMC? 12 PC; DME; GBL; DEE; PC / DME; GBL / DMSO; PC / DEE 513 PC; EC / DME; DMSO; DMF; GBL; PC / DMSO; PC / GBL 514 PC / DEC; EC / DMC; EC / PC; NMF; DME; PC; DME; EC / PC / DMC * S15 PC; DME; GBL; DMF; DMSO; EC / DME; PC / EC; PC / DME; PC / GBL; PC / DMF; PC / DMSO; EC / PC / DME S16 PC; DME; DM? O; DMF; DEC; GBL; NMP; MG; PC / DME; PEG / DME; PC / DM? O; PC / DMF; PC / GBL; THF / GBL; NMP / DMF; MG / GBL; MG / DMSO; EC / DMC; EC / DME S19 DMSO; DMF; GBL? 20 PC; EC / DMC; EC / PC / DMC 521 DMSO; DMF; GBL 522 DME; EC / DMC; DMSO; GBL; DMF S_3 PC; DMSO; PC / DME S24 EC / DMC; GBL; DMSO; EC / PC / DMC; EC / DMC / GBL; EC / DMC / DMSO It was observed that the samples or specimens of S15 employed in the examples described above retain their physical integrity to a particularly high degree while immersing in the various solvents listed in Table 5.

EXAMPLES 139-140 Samples or specimens from each of the hydrolyzed film samples S2, S4, S5,? 6 and S7 they are soaked in PC according to the method described above except that the exposure period was either 2 hours or 54 hours, as indicated in Table 6.

Table 6 Ionic Conductivity of Hydrolyzed Films in PC at Room Temperature EXAMPLES 141-150 The polymeric oil formed by hydrolysis of PolymerXI was mixed with the solvents indicated in Table 7 to form gels at the indicated temperatures. The conductivity measurements were made using a liquid immersion conductivity probe from Orien. The results are shown in Table 7.

Table 7 Ionic conductivities of gel solutions of Polymer XI EXAMPLES 150-173 Samples or specimens of the hydrolyzed films indicated in Table 8 were evaluated by conductivity in an aqueous medium in both the lithiated form prepared as described above, and in the acid form. The membranes in acid form were prepared from the membranes in the form of lithium by immersion of the membrane in an excess of 1.0 M citric acid (Reactive grade, EM Science, Gibbsto n, NJ) for one hour, followed by rinsing at T = 80 ° C in deionized water for one hour and after cooling in deionized water. The films were then treated by immersion in deionized water and heating at T = 80 ° C for two hours, followed by cooling to room temperature. Conductivity was measured using the same procedures above except that all measurements were taken from the glove compartment.

Table 8 Ionic conductivities of ethylene copolymers and fluorosulfonate monomers in Li * and H + form with liquid deionized water at room temperature EXAMPLE 174 Polymer IX synthesized as described above is reacted with CF3CF2S02NNa? I (CH3) 3 according to the method described in Des arteau, J. Fluorine Chem. 52_, pp 7ff (1991) which is incorporated herein by reference . The polymer formed in this way is treated with excess 30% H2SO4 at room temperature for 6 hours to form the polymer in the form of a proton (H +). The proton-shaped polymer formed in this way is then easily exchanged for ions in a large excess of 0.1M LiOH in a 50/50 water / methanol solution at room temperature for 5 hours. The resulting ionomer is a polymer having a substantially unsubstituted ethylene backbone and 3.9 mole% of a suspended group comprising a radical of the formula: - (CH2) 4-0-CF2CF (CF3) -O- (CF2) 2-? 02-N "-S02-CF2CF3 Li * The imide ionomer Li was confirmed by NMR and elemental analysis.

EXAMPLE 175 It was synthesized (CF3CF2 'S02) 2 (BrMg) 2 from CH2 (S02CF2CF3) 2 and CH3MgBr according to the method of ? eppelt, Inorg. Chem. 27_, pp. 2135ff (1988). To a stirred THF solution of the synthesized Polymer IX as described herein above was added (CF3CF2 'S02) 2C (BrMg) 2 at 0 ° C. After the addition was complete, the reaction mixture was stirred at room temperature overnight. The THF is then pumped off, 3M HCl is added, the solution is stirred for several hours and filtered. The solid was washed with water to remove the inorganic salts and then treated with 0.1M LiCl in 50/50 water / MeOH at room temperature overnight. Obtained The resulting ionomer is a polymer having a substantially substituted polyethylene backbone and 3.9 mole% of a suspended group comprising a radical of the formula: - (CH2) 4-0-CF2CF (CF3) -O- (CF2) 2-S02-C "- (S02-CF2CF3) 2 I Li + The Li-ion ionomer is confirmed by NMR and elemental analysis.

EXAMPLE 176 A dry sample of 0.5 g of the hydrolyzed polymer of Example 23 was placed in a flask sealed with 12 g of tetrahydrofuran (THF) and stirred at 400 rpm and a temperature of 65 ° C for 4 hours. Fumed silica (0.125 g of TS530, Cabot Corp., Boston, MA) was added and stirring was continued for several minutes to disperse the silica. The suspension was filtered through a glass wool stopper Remove any gel particles, and empty into a Mylar® polyester film, available from DuPont, with a doctor's blade that has a 0.050"tall door.The THF was allowed to evaporate at room temperature, producing a 32-inch film. to 40 μ thick. The film thus produced was used as the separating film in the battery construction described hereinafter. A second sample of the hydrolyzed polymer of Example 23 was used in the formation of the electrode positive employed in the battery described hereinafter: 0.2 g of the dried ionomer was placed in a sealed flask with 7 g of tetrahydrofuran and stirred at 400 rpm at a temperature of 70 ° C for 2 hours. Carbon black (0.05 g, SP black, MMM added) S.A. Coal, Brussels, Belgium, Gelgium) and graphite (0.75 g of mesophase carbon microbeads MCMB 25-28, Osaka Gas, Japan) and the mixture was stirred for another 15 minutes. The suspension was emptied into silanized Mylar® available from DuPont and the THF was allowed to evaporate at room temperature. A round positive electrode of 12 mm diameter was drilled from the graphite film and dried under vacuum at 100 ° C, giving a mass of 11.6 mg (8.7 mg of graphite) and a thickness of 160 μ. A separator (11.5 mg in mass, 43 μ thick and 19 mm in round diameter) was drilled from the separating film above. These were soaked in excess of anhydrous EC / DMC for 10 minutes, 21.8 mg of liquid absorption. They were mounted with a lithium foil negative electrode in a random cell of size 2325. The cell was discharged with a constant current of 0.5 mA at a voltage of 0.01 V, at which point the voltage was sustained until the current falls below 0.05 mA. The capacity on the first discharge was 2.42 mAh, which corresponds to 280 mAh per g of the graphite positive electrode material. The cell was charged at a rate of 0.5 mA at 1.2 V, and then the voltage was held constant at 1.2 V until the discharge current drops below 0.05 mA. The load capacity was 1.97 mAh, indicating an efficiency 81% electrochemistry in the first discharge / charge cycle. The cell was repeatedly discharged and charged in a similar manner to the previous one, being 1.85 mAh with the discharge capacity 14ava. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (28)

CLAIMS Having described the invention as above, the claim contained in the following claims is claimed as property:

1. An ionomer, characterized in that it comprises? N egjelßbao stain and suspended groups, the skeleton consists essentially of methylene and methine units and the suspended groups comprise ionic radicals of the formula -Rn-Rf-CF2CF2-S02-X- (? 02Rf) a- H * where M + is a univalent metal cation; the Rf groups are independently selected from the group consisting of linear or branched perfluoroalkylene radicals, perfluoroalkylene radicals containing O or Cl, and per fluoroaryl radicals; R is hydrocarbyl and n = 0 or 1; a = 0-2; and X = O, N or C; the ionic radicals being further limited in that a = 0 when X = 0, a = 1 when X = N, and a = 2 when X = C.

2. The ionomer according to claim 1, characterized in that a = 0; X = O; Rf is represented by the formula -0- [(CFRf'CF2) x-Oy] "- where Rf 'is perfluoroalkyl or fluorine, x = 0, 1, 2 or 3, y = 0 or 1, and m = 0, 1, 2 or 3; and Rn is represented by the formula - (CH2.) 2- where z is an integer in the range of 2 to 6.

3. The ionomer according to claim 2, characterized in that M + is an alkali metal cation, Rf 'is fluorine, x = l or 2, y = 0, m = 1 or 2, z = 4, and R is ethyl, propyl or butyl.

4. The ionomer according to claim 3, characterized in that M * is a lithium cation.

5. The ionomer according to claim 1, characterized in that the concentration of the ionic radicals is 1-20% by mol.

6. The ionomer according to claim 1, characterized in that the concentration of the ionic radicals is 2-10 mol%.

7. The ionomer according to claim 1, characterized in that it also comprises up to 150 branches of short chain per 1000 methylene groups in the backbone.

8. The ionomer according to claim 1, characterized in that there are 5-90 branches of short chain per 1000 methylene groups in the backbone or structure.

9. The ionomer according to claim 1, characterized in that it is in the form of a film or sheet.

10. The ionomer according to claim 1, characterized in that it also comprises inorganic particles mixed therewith.

11. The ionomer according to claim 10, characterized in that the inorganic particles are silica particles with an average particle size of less than 1.0 microns, the silica being present in the mixture in up to 50% by weight of the total.

12. An ionically conductive composition, characterized in that it comprises the ionomer according to claim 1 and a saturated liquid therein.

13. The ionically conductive composition according to claim 12, characterized in that the liquid is water or methanol.

14. The ionically conductive composition according to claim 12, characterized in that the liquid is aprotic.

15. The ionically conductive composition according to claim 14, characterized in that the liquid is selected from the group consisting of organic carbonates and mixtures thereof.

16. The ionically conductive composition according to claim 13, characterized in that the liquid is a mixture of ethylene carbonate and at least one liquid selected from the group consisting of dimethyl carbonate, methylethyl carbonate and diethyl carbonate.

17. The ionically conductive composition according to claim 1, characterized in that M * is a lithium cation, R "= (CH2) 4, Rf (CF2) x, X = 0, a = 0, the concentration of the ionic radicals is 2-10 mole%, furthermore it comprises up to 150 branches of short chain per 1000 units of methylene in the skeleton or structure and the liquid. selects from the group consisting of organic carbonates and mixtures thereof.

18. The ionically conductive composition according to claim 12, characterized in that it is in a form selected from the group consisting of a film, sheet and gel.

19. The ionically conductive composition according to claim 17, characterized in that it is in a form selected from the group consisting of a film, sheet and gel.

20. The ionically conductive composition according to claim 18, characterized in that it further comprises an electrically insulating microporous polymeric film or sheet within the micropores of which the gel is "embedded.

21. The ionically conductive composition according to claim 19, characterized in that it further comprises an electrically insulating microporous polymeric film or sheet within the micropores of which the gel is embedded.

22. A process to form an ionomer, the process is characterized in that it comprises contacting a polyolefin comprising a skeleton and suspended groups, the skeleton consists essentially of methylene and methine units and the suspended groups comprise ionic radicals of the formula X ??2-CF2CF2-Rf-R "- where X is F or Cl, Rf is a linear or branched perfluoroalkylene, perfluoroalkylene containing O or Cl, or perfluoroaryl radical, and R is hydrocarbyl where n = 0 or 1, with a solution of an alkali metal base.

23. A process for forming a conductive composition, characterized in that the process comprises contacting the ionomer according to claim 1 with a liquid.

24. An electrode, characterized in that it comprises at least one active electrode material, the ionomer according to claim 1 mixed therewith, and a liquid imbibed therein.

25. The electrode according to claim 24, characterized in that M * is a lithium cation, R "= (CH2) 4, Rf (CF2) x, X = 0, a = 0, the concentration of the ionic radicals is 2- 10 mole%, which further comprises up to 150 short chain branches per 1000 methylene units in the backbone, and the liquid is selected from the group consisting of organic carbonates and mixtures thereof.

26. The electrode according to claim 25, characterized in that it also comprises carbon black.

27. The electrode according to claim 26, characterized in that the weight ratio of the ionomer to the active electrode material is between 0.05 and 0.8 and the weight ratio of the carbon black to the active electrode material is between 0.01 and 0.2.

28. An electrochemical cell, characterized in that it comprises a positive electrode, a negative electrode, a separator disposed between the positive and negative electrodes, and means for connecting the cell to an external load or source where at least one of the group consisting of the separator, the positive electrode, and the negative electrode, comprises the ionomer according to claim 1.