Powder composition based on a fluorinated polymer or a hydrophilic polymer

Abstract

The present invention relates to a powder composition comprising a polymer P1 comprising monomeric units derived from a monomer M0 being vinylidene fluoride or monomeric units derived from a monomer M2 of formula R1R2C=C(R3)C(O)R in which the substituents R1, R2 and R3 are independently selected from the group consisting of H and C1-C5 alkyl; R is selected from the group consisting of –NHC(CH3)2CH2C(O)CH3 or –OR' with R' selected from the group consisting of H and C1-C18 alkyl optionally substituted by one or more –OH group(s) or a five- or six-membered heterocycle comprising at least one nitrogen atom in its cyclic chain; or a mixture of said monomeric units M0 or M2; characterized in that said polymer P1 has a particle size distribution Dv99 less than 89 µm and a size distribution Dv10 greater than 2.0 µm.

Description

Title of the invention: Powder composition based on a fluorinated polymer or a hydrophilic polymer. Technical field

[0001] The present invention relates generally to the field of electrical energy storage in rechargeable Li-ion secondary batteries. More specifically, the invention relates to a composition suitable for use as a coating for a separator. Technological background of the invention

[0002] The market for separators for electrochemical devices is dominated by the use of polyolefins (e.g., Celgard® or Hipore®) produced by extrusion and / or stretching via dry or wet processes. The separators must exhibit both low thickness, optimal affinity for the electrolyte, and sufficient mechanical and temperature resistance. Among the most promising alternatives to polyolefins, polymers with a better affinity for standard electrolytes have been proposed to reduce the internal resistance of the system, such as poly(methyl methacrylate) (PMMA), poly(vinylidene fluoride) (PVDF), and poly(vinylidene fluoride-hexafluoropropene) (P(VDF-co-HFP)). Another option is to deposit a coating on one or both sides of the polyolefin separator.The main evaluation criteria for a separator coating are: dry adhesion, wet adhesion, ionic conductivity, and heat stability.

[0003] Dry adhesion is measured after assembly, by pressing or lamination, of the coated separator with an electrode. This adhesion increases with temperature and pressure applied post-coating. However, it is desirable to use gentle pressing / lamination conditions: reduced pressure to avoid / limit pore closure and thus minimize the impact on ionic conductivity, and moderate temperature to limit energy consumption and maintain high line speed / productivity.

[0004] The wet adhesion of the coating to the separator is measured after impregnation with the electrolyte. This adhesion decreases when the coating is softened by the electrolyte solvents, leading to swelling of the polymer present in the coating, possibly even to the point of coating dissolution. The percentage of swelling, or even dissolution or loss of integrity, is used as a preliminary indication of the wet adhesion performance.

[0005] Ionic conductivity represents the migration of Li ions through the separator and its coating, due to porosity. In aqueous coatings, this porosity corresponds to the interstices between the solid particles that constitute the coating: polymer particles (derived from latex or a powder redispersed in water) and / or ceramics. In solvent-based coatings, this porosity is created by the phase inversion (exposure of the acetone-based coating to moisture, for example) required before or during drying; without phase inversion, simple evaporation of the solvent forms a continuous, non-porous coating. Gurley air permeability is used as a first indication of ionic conductivity.Beyond the air permeability of the initial coated separator, other aspects can affect ionic conductivity: interaction with the electrolyte (favorable when slight swelling of the polymer improves wettability / affinity for the electrolyte, unfavorable when too much swelling of the polymer leads to reduced / clogged pores), the effect of pressing or lamination (reduces / clogged pores).

[0006] Thermal stability is low for polyolefin separators alone (in PE or PP or multilayer PP / PE / PP), which exhibit significant shrinkage at high temperatures. Thermal stability can be substantially improved by a coating containing inorganic particles.

[0007] Poly(vinylidene fluoride) (PVDF) and its derivatives are of interest as the main constituent material of the separator and also as a polyolefin separator coating, due to their electrochemical stability and their high dielectric constant, which promotes ion dissociation and thus conductivity. The copolymer P(VDF-co-HFP) (copolymer of vinylidene fluoride (VDF) and hexafluoropropylene (HFP)) exhibits lower crystallinity than PVDF. Therefore, the advantage of these P(VDF-co-HFP) copolymers is that they enhance conductivity.

[0008] There is still a need to develop new coatings for separators that are easy to implement and that offer a good compromise between dry adhesion, wet adhesion and ionic conductivity.

[0009] The invention therefore aims to remedy at least one of the drawbacks of the prior art, namely to provide a polymeric coating for separator capable of preventing swelling or dissolution in electrolyte solvent(s), while maintaining good adhesion properties and good ionic conductivity. Summary of the invention

[0010] According to a first aspect, the present invention relates to a powder composition comprising a PI polymer including monomeric units derived from a MO monomer being vinylidene fluoride or monomeric units derived of a monomer M2 of formula R'R2C=C(R3)C(O)R in which the substituents R1, R2 and R3 are independently selected from the group consisting of H and C1-C5 alkyl; R is selected from the group consisting of -NHC(CH3)2CH2C(O)CH3 or -OR' with R' selected from the group consisting of H and C1-C18 alkyl optionally substituted by one or more -OH group(s) or a five- or six-membered heterocycle comprising at least one nitrogen atom in its cyclic chain; or a mixture of said monomeric units MO or M2; characterized in that said polymer PI has a particle size distribution Dv99 less than or equal to 89 pm and a particle size distribution DvlO greater than or equal to 2.0 pm.

[0011] Dv99 is the particle size at the 99th percentile (by volume) of the cumulative particle size distribution. This parameter can be determined by laser granulometry. DvlO is the particle size at the 10th percentile (by volume) of the cumulative particle size distribution. This parameter can also be determined by laser granulometry. The particle size distribution is measured using a Microtrac S3500 particle size analyzer and either with water as the dispersion medium or in dry conditions.

[0012] It has been observed that particle size plays an important role in obtaining good adhesion, permeability, or conductivity properties. The PI polymer according to the present invention has a particle size distribution specifically selected to improve at least one of the above properties. Indeed, when the polymer particles are too large with a low basis weight, the separator coverage is too low to achieve the desired properties. If the particles are too small, ion transfer within the separator is insufficient. Furthermore, if the particle size distribution is too heterogeneous, the adhesion properties are reduced.By specifically selecting particles of said PI polymer with a size distribution as mentioned in this application, the separator coatings comprising the composition according to the present invention have shown a good compromise between the different compositions considered.

[0013] According to a preferred embodiment, said PI polymer is a homopolymer of vinylidene fluoride or a copolymer comprising monomeric units derived from vinylidene fluoride and monomeric units derived from a monomer Ml selected from the group consisting of vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, trifluoropropenes, tetrafluoropropenes, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropenes, perfluoroalkylvinyl ethers, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoroethylene and chlorotrifluoropropene or a mixture thereof; or a copolymer comprising monomeric units derived from vinylidene fluoride and monomeric units derived from an M2 monomer as defined in this application.

[0014] According to a preferred embodiment, said PI polymer has a particle size distribution Dv90 less than or equal to 50 pm.

[0015] According to a preferred embodiment, said monomer Ml is hexafluoropropylene.

[0016] According to a preferred embodiment, the mass content of said monomer Ml in said polymer PI is between 0.5% and 15% on the basis of the total weight of said polymer PI or the mass content of said monomer M2 in said polymer PI is between 0.01% and 10% on the basis of the total weight of said polymer PI.

[0017] According to a preferred embodiment, the molten viscosity of said PI polymer is greater than or equal to 60 kP at 230°C and at a shear rate of 100 s-1 measured according to ASTM D3835.

[0018] According to a preferred embodiment, said PI polymer also comprises a functional group selected from the group consisting of carboxylic acid, carboxylic acid anhydride, carboxylic acid esters, epoxy, amide, hydroxyl, carbonyl, mercapto, sulfide, oxazoline, phenolic, ester, ether, siloxane, sulfonic, sulfuric, phosphoric, or phosphonic groups; preferably carboxylic acid, carboxylic acid anhydride, carboxylic acid esters, hydroxyl, phosphoric, and phosphonic.

[0019] According to a preferred embodiment, said polymer PI contains monomeric units derived from a monomer M2 selected from the group consisting of acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-dodecyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, lauryl acrylate, n-octyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, methyl acrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, the t-Butyl methacrylate, n-dodecyl methacrylate, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate,Urea methacrylate and mixtures thereof.

[0020] According to a preferred embodiment, said PI polymer is devoid of fluoro surfactants.

[0021] According to another aspect, the present invention provides a separator for an electrochemical device selected from the group: Li-ion, capacitor, electrical capacitor double-layer, and membrane electrode assembly (MEA) for fuel cell, said separator comprising a porous support and said composition according to the present invention.

[0022] According to another aspect, the present invention provides a secondary Li-ion battery comprising an anode, a cathode and a separator, in which said separator is according to the present invention.

[0023] According to another aspect, the present invention provides a binder for Li-ion battery comprising the composition according to the present invention.

[0024] According to another aspect, the present invention provides a lithium-ion battery electrode comprising a metallic collector of which at least one face is covered with a substrate layer containing an active substance and a binder, characterized in that said binder is according to the present invention.

[0025] According to another aspect, the present invention provides a secondary Li-ion battery comprising an anode, a cathode and a separator, wherein the anode or the cathode is an electrode according to the present invention. Detailed description of the present invention

[0026] According to a first aspect, the present invention provides a composition in powder form comprising a PI polymer.

[0027] PI Polymer

[0028] Said PI polymer may comprise monomeric units derived from a MO monomer being vinylidene fluoride.

[0029] Said polymer PI may comprise monomeric units derived from a monomer M2 of formula R'R2C=C(R3)C(O)R in which the substituents R1, R2, and R3 are independently selected from the group consisting of H and Cr C5 alkyl; R is selected from the group consisting of -NHC(CH3)2CH2C(O)CH3 or -OR' with R' selected from the group consisting of H and CrCi8 alkyl optionally substituted by one or more -OH group(s) or a five- or six-membered heterocycle comprising at least one nitrogen atom in its cyclic chain. Said polymer PI may comprise a mixture of said monomeric units MO and M2.

[0030] Said heterocycle may be saturated, unsaturated, or aromatic. Said heterocycle may be monocyclic or bicyclic. Said heterocycle may be a pyrrole, pyrrolidine, pyridine, piperidine, pyrimidine, pyrazine, 1,4-dihydropyridine, indole, oxindole, isatin, quinoline, isoquinoline, quinazoline, imidazoline, pyrazolidine, 2-pyrrolidone, delta-lactam, succinimide, 2-imidazolidinone, or 4-imidazolidinone ring. Said heterocycle may be substituted by one or more Ci-C5 alkyl groups. As mentioned above, the Ci-Ci8 alkyl group is optionally substituted by said heterocycle. The latter can be linked to the alkyl chain by the nitrogen atom or any other atom forming the heterocycle. Preferably the heterocycle is 2-pyrrolidone, delta-lactam, succinimide, 2-imidazolidinone, 4-imidazolidinone.

[0031] Said monomer M2 may have the formula R'R2C=C(R3)C(O)R in which the substituents R1, R2, and R3 are independently selected from the group consisting of H and C1-C5 alkyl groups; R is selected from the group consisting of -NHC(CH3)2CH2C(O)CH3 or -OR' with R' selected from the group consisting of H and CrCi8 alkyl groups optionally substituted by one or more -OH groups; a five- or ten-membered heterocycle comprising at least one nitrogen atom in its cyclic chain. Preferably, the heterocycle is as defined above, in particular the heterocycle is 2-pyrrolidone, delta-lactam, succinimide, 2-imidazolidinone, or 4-imidazolidinone. Preferably, the substituent R' is selected from the group consisting of H, methyl, ethyl, propyl, n-butyl, isobutyl, t-butyl, n-dodecyl, amyl, isoamyl, hexyl, 2-ethylhexyl, lauryl, n-octyl, hydroxyethyl, hydroxybutyl, hydroxypropyl, ethyl substituted by a ureido group.In particular, said monomer M2 has the formula R'R2C=C(R3)C(O)R in which the substituents R1 and R2 are H; R3 is H or CH3; R is -OR' with R' selected from the group consisting of H, methyl, ethyl, propyl, n-butyl, isobutyl, t-butyl, hydroxypropyl, hydroxybutyl, 2-pyrrolidone, deltalactam, succinimide, 2-imidazolidinone, 4-imidazolidinone. .

[0032] More particularly, said monomer M2 may be acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-dodecyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, lauryl acrylate, n-octyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, methyl acrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-dodecyl methacrylate, Amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, ureido methacrylate and mixtures thereof.Among these, said monomer M2 with an alkyl group having from 1 to 8 carbon atoms is preferred, and an alkyl group having from 1 to 5 carbon atoms is more preferable. Said polymer PI may comprise one or more monomeric units derived from said monomer M2 as defined herein.

[0033] Said PI polymer may comprise monomeric units derived from a monomer Ml copolymerizable with vinylidene fluoride.

[0034] The comonomers compatible with vinylidene fluoride may be halogenated (fluorinated, chlorinated or brominated) or non-halogenated. Said monomer M1 may be selected from the group consisting of vinyl fluoride; trifluoroethylene (VF3); chlorotrifluoroethylene (CTFE); 1,2-difluoroethylene; tetrafluoroethylene (TFE); hexafluoropropylene (HFP); perfluoro(alkyl vinyl) ethers such as perfluoro(methyl vinyl) ether (PMVE), perfluoro(ethyl vinyl) ether (PEVE) and perfluoro(propyl vinyl) ether (PPVE); perfluoro(1,3-dioxole); perfluoro(2,2-dimethyl-1,3-dioxole) (PDD); the monomer of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H; the monomer of formula CF2=CFOCF2CF2SO2F; the monomer of formula F(CF2)nCH2OCF=CF2 in which n is 1, 2, 3, 4 or 5; the monomer of formula R1CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4;The monomer with the formula R2OCF=CH2, where R2 is F(CF2)p and p is 1, 2, 3, or 4; perfluorobutyl ethylene (PFBE); trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene, and 2-trifluoromethyl-3,3,3-trifluoro-1-propene, or a mixture thereof. Examples of trifluoropropene include 3,3,3-trifluoropropene. Examples of tetrafluoropropene include 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene. Examples of pentafluoropropene include 1,1,3,3,3-pentafluoropropene and 1,2,3,3,3-pentafluoropropene. Chlorofluoroethylene can refer to either 1-chloro-1-fluoroethylene or 1-chloro-2-fluoroethylene. The 1-chloro-1-fluoroethylene isomer is preferred. Chlorotrifluoropropene is preferably 1-chloro-3,3,3-trifluoropropene or 2-chloro-3,3,3-trifluoropropene.

[0035] Advantageously, said monomer Ml can be selected from the group consisting of vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers such as perfluoro(methyl vinyl) ether (PMVE), perfluoro(ethyl vinyl) ether (PEVE) and perfluoro(propyl vinyl) ether (PPVE); perfluoro(l,3-dioxole); perfluoro(2,2-dimethyl-l,3-dioxole) (PDD), perfluorobutyl ethylene (PFBE), trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene and 2-trifluoromethyl-3,3,3-trifluoro-l-propene or a mixture thereof.

[0036] Preferably, said monomer Ml can be selected from the group consisting of vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers such as perfluoro(methyl vinyl)ether (PMVE), perfluoro(ethyl vinyl) ether (PEVE) and perfluoro(propyl vinyl) ether (PPVE); perfluorobutyl ethylene (PFBE), trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene and chlorotrifluoropropene or a mixture thereof.

[0037] More preferably, said monomer Ml may be selected from the group consisting of vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(methyl vinyl)ether, perfluoro(ethyl vinyl) ether, perfluoro(propyl vinyl) ether, perfluorobutyl ethylene, trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene and chlorotrifluoropropene or a mixture thereof.

[0038] In particular, said monomer Ml can be selected from the group consisting of vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene and hexafluoropropylene or a mixture thereof.

[0039] According to one embodiment, in said polymer PI, the mass content of vinylidene fluoride units is preferably at least 50%, preferably at least 60%, more preferably greater than 70%, and particularly greater than 80%, based on the total weight of said polymer PI. Thus, the mass content of said monomer Ml in said polymer PI is less than 50%, advantageously less than 40%, preferably less than 30%, more preferably less than 20%, based on the total weight of said polymer PI. According to a preferred embodiment, the mass content of said monomer Ml in said polymer PI is between 0.5% and 20%, advantageously between 0.5% and 19%, preferably between 0.5% and 18%, more preferably between 0.5% and 17%, in particular between 0.5% and 16%, more particularly between 0.5% and 15% on the basis of the total weight of said polymer PI.The mass content of said monomer Ml in said polymer PI may also be between 1% and 20%, advantageously between 1% and 19%, preferably between 1% and 18%, more preferably between 1% and 17%, in particular between 1% and 16%, more particularly between 1% and 15% based on the total weight of said polymer PI. The mass content of said monomer Ml in said polymer PI may also be between 2% and 20%, advantageously between 2% and 19%, preferably between 2% and 18%, more preferably between 2% and 17%, in particular between 2% and 16%, more particularly between 2% and 15% based on the total weight of said polymer PI.

[0040] According to a preferred embodiment, said PI polymer is a copolymer comprising monomeric units derived from vinylidene fluoride and monomeric units derived from hexafluoropropylene; preferably the mass content of the monomeric units derived from vinylidene fluoride is at least 50%, of Preferably at least 60%, more preferably at least 70%, and advantageously at least 80%, based on the total weight of said PI polymer. More particularly, said PI polymer is a copolymer comprising monomeric units derived from vinylidene fluoride and monomeric units derived from hexafluoropropylene; the mass content of the vinylidene fluoride units is greater than 65% and the mass content of the hexafluoropropylene units is less than 35%. Preferably, the PI polymer is a copolymer comprising monomeric units derived from vinylidene fluoride and monomeric units derived from hexafluoropropylene; the mass content of the vinylidene fluoride units is greater than 85% and the mass content of the hexafluoropropylene units is less than 15%.

[0041] According to a particular embodiment, the PI polymer is a copolymer comprising monomeric units derived from vinylidene fluoride and monomeric units derived from hexafluoropropylene; the mass content of hexafluoropropylene is between 0.5% and 20%, advantageously between 0.5% and 19%, preferably between 0.5% and 18%, more preferably between 0.5% and 17%, in particular between 0.5% and 16%, more particularly between 0.5% and 15% based on the total weight of said PI polymer. Advantageously, the PI polymer is a copolymer comprising monomeric units derived from vinylidene fluoride and monomeric units derived from hexafluoropropylene; the mass content of hexafluoropropylene is between 1% and 20%, advantageously between 1% and 19%, preferably between 1% and 18%, more preferably between 1% and 17%, in particular between 1% and 16%, more particularly between 1% and 15% on the basis of the total weight of said PI polymer.Preferably, the PI polymer is a copolymer comprising monomeric units derived from vinylidene fluoride and monomeric units derived from hexafluoropropylene; the mass content of hexafluoropropylene is between 2% and 20%, advantageously between 2% and 19%, preferably between 2% and 18%, more preferably between 2% and 17%, in particular between 2% and 16%, more particularly between 2% and 15%, based on the total weight of said PI polymer. In particular, in this embodiment, the mass content of the vinylidene fluoride units is preferably at least 50%, preferably at least 60%, more preferably greater than 70%, and particularly greater than 80%, based on the total weight of said PI polymer.

[0042] When said polymer PI has a vinylidene fluoride unit mass content of at least 50%, preferably at least 60%, more preferably greater than 70%, and particularly greater than 80%, it may also comprise said monomer M2 in a mass content of 0.05% by weight to 10% by weight based on the total weight of said polymer PI and optionally comprises said monomer M1 according to any one of the embodiments detailed above. Preferably, in this embodiment of realization, said monomer M2 is present in a mass content of 0.05% by weight to 5% by weight, in particular from 0.05 to 2% on the basis of the total weight of said polymer PI.

[0043] When said polymer PI comprises at least 50% by weight of said monomer M2, it may also comprise monomeric units derived from a monomer M3. Said monomer M3 may be

[0044] - (A) an alkenyl compound containing a functional group, or

[0045] - (B) an alkenyl compound without a functional group.

[0046] The alkenyl compound (A) containing a functional group includes, for example, α,[3-unsaturated] carboxylic acids such as acrylic acid, methacrylic acid, fumaric acid, crotonic acid, itaconic acid and the like; vinyl ester compounds such as vinyl acetate, vinyl neodecanoate and the like; amide compounds such as acrylamide, methacrylamide, N-methylacrylamide, N-methylmethacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N-alkylacrylamide, N-alkylmethacrylamide, N,N-dialkylacrylamide, N,N-dialkylmethacrylamide, diacetone acrylamide and the like; acrylic acid esters such as 2-hydroxyethyl acrylate, N-dialkylaminoethyl acrylate, glycidyl acrylate, n-dodecyl acrylate, fluoroalkyl acrylate and the like;Methacrylic acid esters such as dialkylaminoethyl methacrylate, fluoroalkyl methacrylate, 2-hydroxyethyl methacrylate, n-octyl methacrylate, t-butyl methacrylate, glycidyl methacrylate, ethylene glycol dimethacrylate, and the like; maleic anhydride; and alkenyl glycidyl ether compounds such as allyl glycidyl ether and the like. Of these, acrylic acid, methacrylic acid, itaconic acid, fumaric acid, N-methylolacrylamide, N-methylolmethacrylamide, diacetone acrylamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and allyl glycidyl ether are preferred. These compounds may be used alone or in mixtures of two or more. The alkenyl compound without functional group (B) includes, for example, conjugated dienes such as 1,3-butadiene, isoprene and the like;Divinyl hydrocarbon compounds such as divinyl benzene and the like; and alkenyl cyanides such as acrylonitrile, methacrylonitrile, and the like. Among these, 1,3-butadiene and acrylonitrile are preferred. These compounds may be used alone or in mixtures of two or more. Preferably, the functional alkenyl compound (A) should be used in a proportion of less than 50% by weight relative to the weight of the PI polymer, and the alkenyl compound without a functional group (B) should be used in a proportion of less than 30% by weight relative to the weight of the PI polymer.

[0047] As mentioned above, said PI polymer has a particular particle size distribution. This makes it possible to achieve the desired properties and to present a good compromise between adhesion and ionic conductivity.

[0048] Thus, said PI polymer has a particle size distribution Dv99 of less than 89 pm. Dv99 is the particle size at the 99th percentile (by volume) of the cumulative particle size distribution. This parameter can be determined by laser diffraction. This applies to all Dv99 values ​​described herein. This particle size distribution is measured using a particle size analyzer, and the measurement is performed by dry laser diffraction on the powder.Advantageously, said PI polymer has a particle size distribution Dv99 less than or equal to 85 pm, preferably less than or equal to 80 pm, more preferably less than or equal to 75 pm, particularly less than or equal to 70 pm, more particularly less than or equal to 65 pm, preferably less than or equal to 60 pm, advantageously preferred less than or equal to 55 pm, preferably preferred less than or equal to 50 pm, particularly preferred less than or equal to 45 pm.

[0049] Said PI polymer may have a particle size distribution Dv99 greater than or equal to 5 pm, preferably greater than or equal to 7 pm, more preferably greater than or equal to 9 pm, in particular greater than or equal to 11 pm, more particularly greater than or equal to 13 pm, in a preferred manner greater than or equal to 15 pm, advantageously preferred greater than or equal to 17 pm, in a preferred manner greater than or equal to 19 pm, in a particularly preferred manner greater than or equal to 20 pm, in a more particularly preferred manner greater than or equal to 24 pm.

[0050] Thus, according to a particular embodiment, said PI polymer has a particle size distribution Dv99 less than or equal to 89 pm, advantageously less than or equal to 85 pm, preferably less than or equal to 80 pm, more preferably less than or equal to 75 pm, in particular less than or equal to 70 pm, more particularly less than or equal to 65 pm, preferably less than or equal to 60 pm, advantageously preferred less than or equal to 55 pm, preferably preferred less than or equal to 50 pm, particularly preferred less than or equal to 45 pm;and said PI polymer has a particle size distribution Dv99 greater than or equal to 5 pm, preferably greater than or equal to 7 pm, more preferably greater than or equal to 9 pm, in particular greater than or equal to 11 pm, more particularly greater than or equal to 13 pm, preferably greater than or equal to 15 pm, advantageously preferred greater than or equal to 17 pm, preferably preferred greater than or equal to 19 pm, particularly preferred greater than or; equal to 20 pm, more particularly preferred greater than or equal to 24 pm.

[0051] Said PI polymer may also have a particle size distribution DvlO greater than or equal to 2.0 pm. DvlO is the particle size at the 10th percentile (by volume) of the cumulative particle size distribution. This parameter can be determined by laser diffraction as mentioned above. This particle size distribution is also measured using a particle size analyzer, and the measurement is performed by dry laser diffraction on the powder. This applies to all DvlO values ​​described herein.The said PI polymer may have a particle size distribution DvlO greater than or equal to 2.1 pm, advantageously greater than or equal to 2.2 pm, preferably greater than or equal to 2.3 pm, more preferably greater than or equal to 2.4 pm, in particular greater than or equal to 2.5 pm, more particularly greater than or equal to 2.6 pm, preferably greater than or equal to 2.7 pm, advantageously preferred greater than or equal to 2.8 pm, preferably preferred greater than or equal to 2.9 pm, more preferably preferred greater than or equal to 3.0 pm.

[0052] Said PI polymer may have a particle size distribution DvlO greater than or equal to 3.1 pm, advantageously greater than or equal to 3.2 pm, preferably greater than or equal to 3.3 pm, more preferably greater than or equal to 3.4 pm, in particular greater than or equal to 3.5 pm, more particularly greater than or equal to 3.6 pm, preferably greater than or equal to 3.7 pm, advantageously greater than or equal to 3.8 pm, preferably greater than or equal to 3.9 pm, more preferably greater than or equal to 4.0 pm. The said PI polymer may have a particle size distribution DvlO less than or equal to 12 pm, advantageously less than or equal to 11 pm, preferably less than or equal to 10 pm, more preferably less than or equal to 9 pm, in particular less than or equal to 8 pm, more particularly less than or equal to 7 pm.

[0053] Thus, according to a particular embodiment, said polymer PI has a particle size distribution DvlO greater than or equal to 2.0 pm, advantageously greater than or equal to 2.1 pm, preferably greater than or equal to 2.2 pm, more preferably greater than or equal to 2.3 pm, in particular greater than or equal to 2.4 pm, more particularly greater than or equal to 2.5 pm, preferably greater than or equal to 2.6 pm, advantageously greater than or equal to 2.7 pm, preferably greater than or equal to 2.8 pm, more preferably greater than or equal to 2.9 pm, particularly greater than or equal to 3.0 pm; and said polymer PI has a particle size distribution DvlO less than or equal to 12 pm, advantageously less than or equal to 11 pm, preferably less than or equal to 10 pm, more preferably less than or equal to 9 pm, particularly less than or equal to 8 pm, more particularly less than or equal to 7 pm.

[0054] Thus, according to a particular embodiment, said PI polymer has a particle size distribution DvlO greater than or equal to 3.1 pm, advantageously greater than or equal to 3.2 pm, preferably greater than or equal to 3.3 pm, more preferably greater than or equal to 3.4 pm, in particular greater than or equal to 3.5 pm, more particularly greater than or equal to 3.6 pm, preferably greater than or equal to 3.7 pm, advantageously more preferably greater than or equal to 3.8 pm, preferably greater than or equal to 3.9 pm, more preferably greater than or equal to 4.0 pm; and said PI polymer has a particle size distribution DvlO less than or equal to 12 pm, advantageously less than or equal to 11 pm, preferably less than or equal to 10 pm, more preferably less than or equal to 9 pm, in particular less than or equal to 8 pm, more particularly less than or equal to 7 pm.

[0055] Said PI polymer may also have a particle size distribution Dv90 of less than 50 pm. Dv90 is the particle size at the 90th percentile (by volume) of the cumulative particle size distribution. This parameter can be determined by laser diffraction as mentioned above. This particle size distribution is also measured using a particle size analyzer, and the measurement is performed by dry laser diffraction on the powder. This applies to all Dv90 values ​​described herein.Advantageously, said PI polymer has a particle size distribution Dv90 less than or equal to 48 pm, preferably less than or equal to 46 pm, more preferably less than or equal to 44 pm, in particular less than or equal to 42 pm, more particularly less than or equal to 40 pm, preferably less than or equal to 38 pm, advantageously preferred less than or equal to 36 pm, preferably preferred less than or equal to 34 pm, particularly preferred less than or equal to 32 pm, more particularly preferred less than or equal to 30 pm.The said PI polymer may have a particle size distribution Dv90 greater than or equal to 1 pm, advantageously greater than or equal to 2 pm, preferably greater than or equal to 3 pm, more preferably greater than or equal to 4 pm, in particular greater than or equal to 5 pm, more particularly greater than or equal to 6 pm, preferably greater than or equal to 7 pm, advantageously preferred greater than or equal to 8 pm, preferably preferred greater than or equal to 9 pm, particularly preferred greater than or equal to 10 pm.

[0056] Thus, according to a particular embodiment, said PI polymer has a particle size distribution Dv90 less than or equal to 50 pm, advantageously less than or equal to 48 pm, preferably less than or equal to 46 pm, more preferably less than or equal to 44 pm, in particular less than or equal to 42 pm, more particularly less than or equal to 40 pm, preferably less than or equal to 38 pm, advantageously preferred less than or equal to 36 pm, preferably preferred less than or equal to 34 pm, particularly preferred less than or equal to 32 pm, more particularly preferred less than or equal to 30 pm;and said PI polymer has a particle size distribution Dv90 greater than or equal to 1 pm, advantageously greater than or equal to 2 pm, preferably greater than or equal to 3 pm, more preferably greater than or equal to 4 pm, in particular greater than or equal to 5 pm, more particularly greater than or equal to 6 pm, preferably greater than or equal to 7 pm, advantageously preferred greater than or equal to 8 pm, preferably preferred greater than or equal to 9 pm, particularly preferred greater than or equal to 10 pm.

[0057] According to a preferred embodiment, said PI polymer has a particle size distribution - Dv99 less than or equal to 89 pm, advantageously, less than or equal to 85 pm, preferably less than or equal to 80 pm, more preferably less than or equal to 75 pm, in particular less than or equal to 70 pm, more particularly less than or equal to 65 pm, preferably less than or equal to 60 pm, advantageously preferred less than or equal to 55 pm, preferentially preferred less than or equal to 50 pm, particularly preferred less than or equal to 45 pm; - DvlO greater than or equal to 2.0 pm, advantageously greater than or equal to 2.1 pm, preferably greater than or equal to 2.2 pm, more preferably greater than or equal to 2.3 pm, in particular greater than or equal to 2.4 pm, more particularly greater than or equal to 2.5 pm, preferably greater than or equal to 2.6 pm, advantageously greater than or equal to 2.7 pm, preferentially greater than or equal to 2.8 pm, more preferentially greater than or equal to 2.9 pm, particularly greater than or equal to 3.0 pm or DvlO greater than or equal to 3.1 pm, advantageously greater than or equal to 3.2 pm, preferably greater than or equal to 3.3 pm, more preferably greater than or equal to 3.4 pm, in particular greater than or equal to 3.5 pm, more particularly greater than or equal to 3.6 pm, preferably greater than or equal to 3.7 pm, advantageously preferred at 3.8 pm or greater, preferentially at 3.9 pm or greater, and more preferentially at 4.0 pm or greater; and - Dv90 less than or equal to 50 pm, advantageously less than or equal to 48 pm, preferably less than or equal to 46 pm, more preferably less than or equal to 44 pm, in particular less than or equal to 42 pm, more particularly less than or equal to 40 pm, preferably less than or equal to 38 pm, advantageously preferred less than or equal to 36 pm, preferentially preferred less than or equal to 34 pm, particularly preferred less than or equal to 32 pm, more particularly preferred less than or equal to 30 pm.

[0058] According to another preferred embodiment, said PI polymer has a particle size distribution - Dv99 less than or equal to 89 pm, advantageously, less than or equal to 85 pm, preferably less than or equal to 80 pm, more preferably less than or equal to 75 pm, in particular less than or equal to 70 pm, more particularly less than or equal to 65 pm, preferably less than or equal to 60 pm, advantageously preferred less than or equal to 55 pm, preferentially preferred less than or equal to 50 pm, particularly preferred less than or equal to 45 pm;and greater than or equal to 5 pm, preferably greater than or equal to 7 pm, more preferably greater than or equal to 9 pm, in particular greater than or equal to 11 pm, more particularly greater than or equal to 1 pm, preferably greater than or equal to 3 pm, advantageously greater than or equal to 5 pm, preferably greater than or equal to 7 pm, particularly greater than or equal to 7 pm, particularly greater than or equal to 8 pm, more particularly greater than or equal to 12 pm; - DvlO greater than or equal to 2.0 pm, advantageously greater than or equal to 2.1 pm, preferably greater than or equal to 2.2 pm, more preferably greater than or equal to 2.3 pm, in particular greater than or equal to 2.4 pm, more particularly greater than or equal to 2.5 pm, preferably greater than or equal to 2.6 pm, advantageously greater than or equal to 2.7 pm, preferably greater than or equal to 2.8 pm, more preferably greater than or equal to 2.9 pm, particularly greater than or equal to 3.0 pm or DvlO greater than or equal to 3.1 pm, advantageously greater than or equal to 3.2 pm, preferably greater than or equal to 3.3 pm, more preferably greater than or equal to 3.4 pm, in particular greater than or equal to 3.5 pm, more particularly greater than or equal to 3.6 pm, preferably greater than or equal to 3.7 pm, advantageously greater than or equal to 3.8 pm, preferably greater than or equal to 3.9 pm, more preferably greater than or equal to 4.0 pm; and less than or equal to 12 pm, advantageously less than or equal to 11 pm, preferably less than or equal to 10 pm, more preferably less than or equal to 9 pm, in particular less than or equal to 8 pm, more particularly less than or equal to 7 pm; - Dv90 less than or equal to 50 pm, advantageously less than or equal to 48 pm, preferably less than or equal to 46 pm, more preferably less than or equal to 44 pm, in particular less than or equal to 42 pm, more particularly less than or equal to 40 pm, preferably less than or equal to 38 pm, advantageously preferred less than or equal to 36 pm, preferentially preferred less than or equal to 34 pm, particularly preferred less than or equal to 32 pm, more particularly preferred less than or equal to 30 pm;and greater than or equal to 1 pm, advantageously greater than or equal to 2 pm, preferably greater than or equal to 3 pm, more preferably greater than or equal to 4 pm, in particular greater than or equal to 5 pm, more particularly greater than or equal to 6 pm, preferably greater than or equal to 7 pm, advantageously greater than or equal to 8 pm, preferably greater than or equal to 9 pm, particularly greater than or equal to 10 pm. ;

[0059] According to a preferred embodiment, when the PI polymer comprises MO monomeric units, at least 50% by weight based on its total weight, and optionally Ml, the melt viscosity of said PI polymer is greater than or equal to 40 kP at 230°C and at a shear rate of 100 s-1 measured according to ASTM D3835. Advantageously, the melt viscosity of said PI polymer is greater than or equal to 45 kP, preferably greater than or equal to 50 kP, more preferably greater than or equal to 55 kP, in particular greater than or equal to 60 kP at 230°C and at a shear rate of 100 s-1 measured according to ASTM D3835.

[0060] According to a particular embodiment, when the PI polymer comprises MO monomeric units, at least 50% by weight based on its total weight, and optionally Ml, the PI polymer comprises a functional group that improves adhesion to metal. Thus, said PI polymer can comprising monomeric units bearing at least one of the functions selected from the group consisting of carboxylic acid, carboxylic acid anhydride, carboxylic acid esters, epoxy groups such as glycidyl, amide, hydroxyl, carbonyl, mercapto, sulfide, oxazoline, phenolic, ester, ether, siloxane, sulfonic, sulfuric, phosphoric, phosphonic; preferably carboxylic acid, carboxylic acid anhydride, carboxylic acid esters, hydroxyl, phosphoric and phosphonic; in particular at least one carboxylic acid, carboxylic acid anhydride, carboxylic acid ester function. The functional group can be introduced by a chemical reaction which can be grafting, or copolymerization with a monomer bearing at least one of said functional groups and a vinyl function capable of copolymerizing with vinylidene fluoride or monomer Ml, according to techniques well known to those skilled in the art.The functionality can be introduced via the transfer agent used in the synthesis process of said PI polymer. The transfer agent can be a polymer with a molar mass less than or equal to 20,000 g / mol and bearing functional groups selected from the following: carboxylic acid, carboxylic acid anhydride, carboxylic acid esters, epoxy groups (such as glycidyl), amide, hydroxyl, carbonyl, mercapto, sulfide, oxazoline, phenolic, ester, ether, siloxane, sulfonic, sulfuric, phosphoric, and phosphonic groups. An example of such a transfer agent is acrylic acid oligomers. In a preferred embodiment, the transfer agent is an acrylic acid oligomer with a molar mass less than or equal to 20,000 g / mol. Alternatively, the functional group can be introduced by an oligomeric or polymeric compound comprising said functional group and mixed with the PI polymer.The oligomeric or polymeric compound may be impregnated in, mixed with, or intimately blended with the PI polymer. In this case, the functional group may be derived from a (meth)acrylic acid compound selected from acrylic acid, methacrylic acid, hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, hydroxyethylhexyl(meth)acrylate, and acryloyloxy propylsuccinate. For example, the functional group may be an oligomer or a polymer comprising monomeric units derived from a monomer selected from the group consisting of acrylic acid, methacrylic acid, hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, hydroxyethylhexyl(meth)acrylate, and acryloyloxy propylsuccinate.According to one embodiment, said oligomer or polymer has a weight-average molecular mass less than or equal to 100,000 g / mol, advantageously less than 80,000 g / mol, preferably less than 60,000 g / mol, more preferably less than 40,000 g / mol, and in particular less than 20,000 g / mol. The weight-average molecular mass is determined by GPC using [method not specified in the original text]. A Waters 2695e instrument coupled to a Wyatt NEON refractometer equipped with two PL Gel mixed C columns and one guard column (7.8 mm LD x 30 cm, 5 µm) was used under the following conditions: Temperature: 35°C; flow rate: 1.0 mL / min; injection volume: 100 pL. Samples were prepared at a concentration of 1 mg / mL in THF. Twelve poly(methyl methacrylate) samples with a molecular mass of 535 to 2,210,000 g / mol were used as calibration standards. When containing a functional group as mentioned above, the content of that functional group in said PI polymer was at least 0.01 mol%, preferably at least 0.1 mol%, and at most 15 mol%, preferably at most 10 mol%.

[0061] According to a particular embodiment, when said PI polymer comprises monomeric units derived from a monomer M2, at least 50% by weight based on the total weight thereof, said PI polymer has a pH between 1.5 and 4.0, advantageously between 1.6 and 3.9, preferably between 1.7 and 3.8, more preferably between 1.8 and 3.7, in particular between 1.9 and 3.6, more particularly between 2.0 and 3.5, measured in water at room temperature. To measure the pH, a Mettler Toledo SevenEasy or equivalent pH meter and an Electrode In Lab Routine Pro are used. Before calibration, the electrode is checked for cleanliness. If necessary, clean the electrode with warm soapy water. Ensure that the pH electrode is always kept filled with KC1 filling solution. The device is calibrated with buffer solutions of pH 10, 7 and 4.To calibrate, immerse the electrode in the pH 10 buffer solution and press Cal. Once the pH has stabilized, repeat the operation with pH 7 buffer, then pH 4. Rinse with distilled water and dry the electrode between each buffer. The electrode is prepared beforehand by soaking it in a 0.1M HCl solution for one to two hours, then rinsed with deionized water. To measure the pH, immerse the electrode in the sample to be tested and stir for a few seconds. Allow the measurement to stabilize for 15 minutes and read the value displayed on the pH meter. The measurement is taken at room temperature.

[0062] Preferably, when said PI polymer comprises monomeric units derived from a monomer M2, at least 50% by weight based on the total weight thereof, said PI polymer has a glass transition temperature less than or equal to 230°C. Advantageously, said PI polymer has a glass transition temperature less than or equal to 220°C, preferably less than 200°C, more preferably less than 180°C, in particular less than 160°C, and more particularly less than or equal to 150°C. The glass transition temperatures indicated herein are calculated using the Fox equation. The Fox equation is an equation used to predict the glass transition temperature of statistical copolymers:

[0063] 1 / Tg,copo ~ £i coi / Tg,i

[0064] Tg,copo is the glass transition temperature of the copolymer,

[0065] Tg, i are the mass fractions of the homopolymers i corresponding to each comonomer,

[0066] coi are the mass fractions of the monomers i composing this copolymer.

[0067] Mass fractions are expressed without units. Glass transition temperatures are expressed in Kelvin. The temperature is then converted to Celsius.

[0068] As mentioned above, said PI polymer is free of fluorosurfactants. Said PI polymer may comprise between 10 ppm and 2 wt% of a surfactant comprising polyethylene glycol or polypropylene glycol units. Preferably, said surfactant has an HLB value of 1 to 20, in particular an HLB value of 1 to 5 or 10 to 15. In particular, said surfactant comprises a polyethylene glycol segment and a polypropylene glycol segment, and has an HLB value of 1 to 5 and a weight-average molecular weight of 5000 to 10000 g·mol⁻¹. Alternatively, said surfactant comprises a polyethylene glycol segment and a polypropylene glycol segment, and has an HLB value of 10 to 15 and a weight-average molecular weight of 500 to 2500 g·mol⁻¹. Composition

[0069] Preferably, said composition according to the present invention comprises at least 50%, advantageously at least 60%, preferably at least 70%, more preferably at least 80%, in particular at least 90%, more particularly at least 95% by weight of said PI polymer according to the present invention on the basis of the total weight of said composition.

[0070] According to a particular embodiment, where the polymer PI comprises monomeric units MO, at least 50% by weight based on its total weight, and optionally Ml, said composition may optionally comprise a polymer P2 comprising monomeric units derived from a monomer selected from the group consisting of acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-dodecyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, lauryl acrylate, n-octyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, methyl acrylic acid, methacrylate of methyl, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-dodecyl methacrylate,Amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, and ureido methacrylate.

[0071] According to a particular embodiment, when the polymer PI comprises monomeric units M2, at least 50% by weight based on its total weight, said composition may optionally comprise a polymer P3 comprising monomeric units comprising monomeric units derived from a monomer selected from the group consisting of vinylidene fluoride or a monomer Ml as defined in this application or a mixture thereof.

[0072] Said PI polymer can be obtained by an emulsion or suspension polymerization process according to conventional techniques known to those skilled in the art. The PI polymer is generally obtained in the form of a latex, a dispersion, or an aqueous solution. The composition according to the present invention can be obtained from a latex comprising said PI polymer by a drying step followed by a step enabling the desired size distribution to be achieved. The drying step can be carried out by spray drying or co-spray drying, preferably at a temperature of 100°C to 220°C, or by freeze-drying. The powder can also be obtained by grinding techniques, such as cryo-milling, where the mixture is brought to a temperature below ambient temperature, for example by means of liquid nitrogen, before grinding.At the end of the powder manufacturing stage, i.e., after the drying stage, the particle size can be adjusted and optimized by selection or screening processes and / or by grinding, granulation, sieving, compaction, or shearing. One or more of these techniques can be used to achieve the desired size distribution.

[0073] When the composition comprises, in addition to polymer PI, said polymer P2 or said polymer P3, said polymers may be mixed in powder form, or in the form of an aqueous dispersion followed by drying. Said polymer PI may also form an interpenetrating polymer network (IPN or semi-IPN) with said polymer P2 or said polymer P3.

[0074] Preferably, polymer P2 and polymer P3 have a size distribution in the same range as polymer P1. Thus, polymer P2 or polymer P3 has a particle size distribution Dv99 of less than 89 pm. Dv99 is the particle size at the 99th percentile (by volume) of the cumulative particle size distribution. This parameter can be determined by laser diffraction. This applies to all Dv99 values ​​described herein. This particle size distribution is measured using a particle size analyzer, and the measurement is performed dry by laser diffraction on the powder.Advantageously, said polymer P2 or said polymer P3 has a particle size distribution Dv99 less than or equal to 85 pm, preferably less than or equal to 80 pm, more preferably less than or equal to 75 pm, in particular less than or equal to 70 pm, more particularly less than or equal to 65 pm, preferably less than or equal to 60 pm, advantageously preferred less than or equal to 55 pm, preferably preferred less than or equal to 50 pm, particularly preferred less than or equal to 45 pm.

[0075] Said polymer P2 or said polymer P3 may have a particle size distribution Dv99 greater than or equal to 5 pm, preferably greater than or equal to 7 pm, more preferably greater than or equal to 9 pm, in particular greater than or equal to 11 pm, more particularly greater than or equal to 13 pm, preferably greater than or equal to 15 pm, advantageously preferred greater than or equal to 17 pm, preferably preferred greater than or equal to 19 pm, particularly preferred greater than or equal to 20 pm, more particularly preferred greater than or equal to 24 pm.

[0076] Thus, according to a particular embodiment, said polymer P2 or said polymer P3 has a particle size distribution Dv99 less than or equal to 89 pm, advantageously less than or equal to 85 pm, preferably less than or equal to 80 pm, more preferably less than or equal to 75 pm, in particular less than or equal to 70 pm, more particularly less than or equal to 65 pm, preferably less than or equal to 60 pm, advantageously preferred less than or equal to 55 pm, preferably preferred less than or equal to 50 pm, particularly preferred less than or equal to 45 pm;and said polymer P2 or said polymer P3 has a particle size distribution Dv99 greater than or equal to 5 pm, preferably greater than or equal to 7 pm, more preferably greater than or equal to 9 pm, in particular greater than or equal to 11 pm, more particularly greater than or equal to 13 pm, preferably greater than or equal to 15 pm, advantageously preferred greater than or equal to 17 pm, preferably preferred greater than or equal to 19 pm, particularly preferred greater than or equal to 20 pm, more particularly preferred greater than or equal to 24 pm.

[0077] Said polymer P2 or polymer P3 may also have a particle size distribution DvlO greater than or equal to 2.0 pm. DvlO is the particle size at the 10th percentile (by volume) of the cumulative particle size distribution. This parameter can be determined by laser diffraction as mentioned above. This particle size distribution is also measured using a particle size analyzer, and the measurement is performed by dry laser diffraction on the powder. This applies to all DvlO values ​​described herein.The said polymer P2 or the said polymer P3 may have a particle size distribution DvlO greater than or equal to 2.1 pm, advantageously greater than or equal to 2.2 pm, preferably greater than or equal to 2.3 pm, more preferably greater than or equal to 2.4 pm, in particular greater than or equal to 2.5 pm, more particularly greater than or equal to 2.6 pm, preferably greater than or equal to 2.7 pm, advantageously preferably greater than or equal to 2.8 pm. preferentially preferred greater than or equal to 2.9 pm, more preferentially preferred greater than or equal to 3.0 pm.

[0078] Said polymer P2 or said polymer P3 may have a particle size distribution DvlO greater than or equal to 3.1 pm, advantageously greater than or equal to 3.2 pm, preferably greater than or equal to 3.3 pm, more preferably greater than or equal to 3.4 pm, in particular greater than or equal to 3.5 pm, more particularly greater than or equal to 3.6 pm, preferably greater than or equal to 3.7 pm, advantageously greater than or equal to 3.8 pm, preferably greater than or equal to 3.9 pm, more preferably greater than or equal to 4.0 pm. The said polymer P2 or the said polymer P3 may have a particle size distribution DvlO less than or equal to 12 pm, advantageously less than or equal to 11 pm, preferably less than or equal to 10 pm, more preferably less than or equal to 9 pm, in particular less than or equal to 8 pm, more particularly less than or equal to 7 pm.

[0079] Thus, according to a particular embodiment, said polymer P2 or said polymer P3 has a particle size distribution DvlO greater than or equal to 2.0 pm, advantageously greater than or equal to 2.1 pm, preferably greater than or equal to 2.2 pm, more preferably greater than or equal to 2.3 pm, in particular greater than or equal to 2.4 pm, more particularly greater than or equal to 2.5 pm, preferably greater than or equal to 2.6 pm, advantageously preferred greater than or equal to 2.7 pm, preferably preferred greater than or equal to 2.8 pm, more preferably preferred greater than or equal to 2.9 pm, particularly preferred greater than or equal to 3.0 pm;and said polymer P2 or said polymer P3 has a particle size distribution DvlO less than or equal to 12 pm, advantageously less than or equal to 11 pm, preferably less than or equal to 10 pm, more preferably less than or equal to 9 pm, in particular less than or equal to 8 pm, more particularly less than or equal to 7 pm.

[0080] Thus, according to a particular embodiment, said polymer P2 or said polymer P3 has a particle size distribution DvlO greater than or equal to 3.1 pm, advantageously greater than or equal to 3.2 pm, preferably greater than or equal to 3.3 pm, more preferably greater than or equal to 3.4 pm, in particular greater than or equal to 3.5 pm, more particularly greater than or equal to 3.6 pm, preferably greater than or equal to 3.7 pm, advantageously greater than or equal to 3.8 pm, preferably greater than or equal to 3.9 pm, more preferably greater than or equal to 4.0 pm; and said polymer P2 or said polymer P3 has a particle size distribution DvlO less than or equal to 12 pm, advantageously less than or equal to 11 pm, preferably less than or equal to 10 pm, more preferably less than or equal to 9 pm, in particular less than or equal to 8 pm, more particularly less than or equal to 7 pm.

[0081] Said polymer P2 or polymer P3 may also have a particle size distribution Dv90 of less than 50 pm. Dv90 is the particle size at the 90th percentile (by volume) of the cumulative particle size distribution. This parameter can be determined by laser diffraction as mentioned above. This particle size distribution is also measured using a particle size analyzer, and the measurement is performed by dry laser diffraction on the powder. This applies to all Dv90 values ​​described herein.Advantageously, said polymer P2 or said polymer P3 has a particle size distribution Dv90 less than or equal to 48 pm, preferably less than or equal to 46 pm, more preferably less than or equal to 44 pm, in particular less than or equal to 42 pm, more particularly less than or equal to 40 pm, preferably less than or equal to 38 pm, advantageously preferred less than or equal to 36 pm, preferably preferred less than or equal to 34 pm, particularly preferred less than or equal to 32 pm, more particularly preferred less than or equal to 30 pm.The polymer P2 or the polymer P3 may have a particle size distribution Dv90 greater than or equal to 1 pm, advantageously greater than or equal to 2 pm, preferably greater than or equal to 3 pm, more preferably greater than or equal to 4 pm, in particular greater than or equal to 5 pm, more particularly greater than or equal to 6 pm, preferably greater than or equal to 7 pm, advantageously greater than or equal to 8 pm, preferably greater than or equal to 9 pm, particularly greater than or equal to 10 pm.

[0082] Thus, according to a particular embodiment, said polymer P2 or said polymer P3 has a particle size distribution Dv90 less than or equal to 50 pm, advantageously less than or equal to 48 pm, preferably less than or equal to 46 pm, more preferably less than or equal to 44 pm, in particular less than or equal to 42 pm, more particularly less than or equal to 40 pm, preferably less than or equal to 38 pm, advantageously preferred less than or equal to 36 pm, preferably preferred less than or equal to 34 pm, particularly preferred less than or equal to 32 pm, more particularly preferred less than or equal to 30 pm;and said polymer P2 or said polymer P3 has a particle size distribution Dv90 greater than or equal to 1 pm, advantageously greater than or equal to 2 pm, preferably greater than or equal to 3 pm, more preferably greater than or equal to 4 pm, in particular greater than or equal to 5 pm, more particularly greater; or equal to 6 pm, preferentially greater than or equal to 7 pm, advantageously greater than or equal to 8 pm, preferentially greater than or equal to 9 pm, particularly greater than or equal to 10 pm.

[0083] According to a preferred embodiment, said polymer P2 or said polymer P3 has a particle size distribution - Dv99 less than or equal to 89 pm, advantageously, less than or equal to 85 pm, preferably less than or equal to 80 pm, more preferably less than or equal to 75 pm, in particular less than or equal to 70 pm, more particularly less than or equal to 65 pm, preferably less than or equal to 60 pm, advantageously preferred less than or equal to 55 pm, preferentially preferred less than or equal to 50 pm, particularly preferred less than or equal to 45 pm; - DvlO greater than or equal to 2.0 pm, advantageously greater than or equal to 2.1 pm, preferably greater than or equal to 2.2 pm, more preferably greater than or equal to 2.3 pm, in particular greater than or equal to 2.4 pm, more particularly greater than or equal to 2.5 pm, preferably greater than or equal to 2.6 pm, advantageously greater than or equal to 2.7 pm, preferentially greater than or equal to 2.8 pm, more preferentially greater than or equal to 2.9 pm, particularly greater than or equal to 3.0 pm or DvlO greater than or equal to 3.1 pm, advantageously greater than or equal to 3.2 pm, preferably greater than or equal to 3.3 pm, more preferably greater than or equal to 3.4 pm, in particular greater than or equal to 3.5 pm, more particularly greater than or equal to 3.6 pm, preferably greater than or equal to 3.7 pm,advantageously preferred at 3.8 pm or greater, preferentially at 3.9 pm or greater, more preferentially at 4.0 pm or greater; and, - Dv90 less than or equal to 50 pm, advantageously less than or equal to 48 pm, preferably less than or equal to 46 pm, more preferably less than or equal to 44 pm, in particular less than or equal to 42 pm, more particularly less than or equal to 40 pm, preferably less than or equal to 38 pm, advantageously preferred less than or equal to 36 pm, preferentially preferred less than or equal to 34 pm, particularly preferred less than or equal to 32 pm, more particularly preferred less than or equal to 30 pm.

[0084] According to another preferred embodiment, said polymer P2 or said polymer P3 has a particle size distribution - Dv99 less than or equal to 89 pm, advantageously, less than or equal to 85 pm, preferably less than or equal to 80 pm, more preferably less than or equal to 75 pm, in particular less than or equal to 70 pm, more particularly less than or equal to 65 pm, preferably less than or equal to 60 pm, advantageously preferred less than or equal to 55 pm, preferentially preferred less than or equal to 50 pm, particularly preferred less than or equal to 45 pm;and greater than or equal to 5 pm, preferably greater than or equal to 7 pm, more preferably greater than or equal to 9 pm, in particular greater than or equal to 11 pm, more particularly greater than or equal to 1 pm, preferably greater than or equal to 3 pm, advantageously greater than or equal to 5 pm, preferably greater than or equal to 7 pm, particularly greater than or equal to 7 pm, particularly greater than or equal to 8 pm, more particularly greater than or equal to 12 pm; - DvlO greater than or equal to 2.0 pm, advantageously greater than or equal to 2.1 pm, preferably greater than or equal to 2.2 pm, more preferably greater than or equal to 2.3 pm, in particular greater than or equal to 2.4 pm, more particularly greater than or equal to 2.5 pm, preferably greater than or equal to 2.6 pm, advantageously greater than or equal to 2.7 pm, preferentially greater than or equal to 2.8 pm, more preferentially greater than or equal to 2.9 pm, particularly greater than or equal to 3.0 pm or DvlO greater than or equal to 3.1 pm, advantageously greater than or equal to 3.2 pm, preferably greater than or equal to 3.3 pm, more preferably greater than or equal to 3.4 pm, in particular greater than or equal to 3.5 pm, more particularly greater than or equal to 3.6 pm, preferably greater than or equal to 3.7 pm,advantageously preferred greater than or equal to 3.8 pm, preferentially greater than or equal to 3.9 pm, more preferably greater than or equal to 4.0 pm; and less than or equal to 12 pm, advantageously less than or equal to 11 pm, preferably less than or equal to 10 pm, more preferably less than or equal to 9 pm, in particular less than or equal to 8 pm, more particularly less than or equal to 7 pm; , - Dv90 less than or equal to 50 pm, advantageously less than or equal to 48 pm, preferably less than or equal to 46 pm, more preferably less than or equal to 44 pm, in particular less than or equal to 42 pm, more particularly less than or equal to 40 pm, preferably less than or equal to 38 pm, advantageously preferred less than or equal to 36 pm, preferentially preferred less than or equal to 34 pm, particularly preferred less than or equal to 32 pm, more particularly preferred less than or equal to 30 pm;and greater than or equal to 1 pm, advantageously greater than or equal to 2 pm, preferably greater than or equal to 3 pm, more preferably greater than or equal to 4 pm, in particular greater than or equal to 5 pm, more particularly greater than or equal to 6 pm, preferably greater than or equal to 7 pm, advantageously greater than or equal to 8 pm, preferably greater than or equal to 9 pm, particularly greater than or equal to 10 pm. ; Separator

[0085] The composition according to the present invention can be used as one of the materials for preparing a separator in an electrochemical device. The composition is preferably used in the separator coating. In addition to the composition, the separator coating may contain inorganic particles that serve to form micropores in the coating (the spaces between the inorganic particles). The addition of inorganic particles can also contribute to heat resistance or improve wettability. In one embodiment, the coating comprises from 50 to 99 percent by weight of inorganic particles, relative to the weight of the coating. These inorganic particles must be electrochemically stable (not subject to oxidation and / or reduction within the voltage range used). Furthermore, the powdered inorganic materials preferably have high ionic conductivity.Low-density materials are preferred to higher-density materials because the weight of the battery produced can be reduced. The dielectric constant is preferably equal to or greater than 5. In one embodiment, said inorganic particles are chosen from the group consisting of: BaTiO3, Pb(Zr,Ti)O3, Pb 1-x LaxZryO3 (0 <x<l, 0<y< 1), PBMg3Nb2 / 3)3,PbTiO3, hafnie (HfO (HfO2), SrTiO 3, SnO2, CeO2, MgO, NiO, CaO, ZnO, Y2O3, bohémite (y-AlO(OH)), A12O3, TiO2, SiC, ZrO2, silicate de bore, BaSO4, nano-argiles, ou leurs mélanges. Dans ce cas, le rapport des solides du polymère PI, et optionnellement P2 et P3, aux particules inorganiques est de 0,5 à 40 parties en poids de solides de la composition totale pour 60 à 99,5 parties en poids de particules inorganiques. Avantageusement, le rapport des solides du . The ratio of polymer PI, and optionally P2 and P3, to inorganic particles is 0.5 to 35 parts by weight to 65 to 99.5 parts by weight of inorganic particles. Preferably, the ratio of solids of polymer PI, and optionally P2 and P3, to inorganic particles is 0.5 to 30 parts by weight to 70 to 99.5 parts by weight of inorganic particles. The separator coating may optionally comprise 0 to 15% by weight of the polymer base, and preferably 0.1 to 10% by weight of additives, selected from thickeners, pH adjusters, anti-sedimentation agents, surfactants, wetting agents, fillers, anti-foaming agents, and fugitive or non-fugitive adhesion promoters. The fillers mentioned here in the additives are different from the inorganic particles mentioned above.

[0086] The separator according to the present invention comprises a coating, as described above, optionally disposed on one or both faces of a porous support. In this case, the coating is used to coat the separator support, on at least one face, in the form of a single layer or multiple layers. There is no particular limitation in the choice of the support to be coated with the coating of the invention, as long as it is a porous substrate having pores. The support may comprise a single layer or several distinct layers. When it comprises several layers, the coating as described in the present invention is disposed on the external face of the support, that is to say, on the face that will first come into contact with the electrolytic composition used in the battery. Advantageously, the coating is applied to the support using an aqueous or solvent-based method.The porous substrate can be in the form of a membrane or a fibrous fabric. When the porous substrate is fibrous, it can be a nonwoven fabric forming a porous veil, such as a veil obtained by direct spinning or melt blowing (of the "spunbond" or "melt blown" type) or electrospinning. Examples of porous substrates useful in the invention as a support include, but are not limited to: polyolefins, polyethylene terephthalate, polybutylene terephthalate, polyester, polyacetal, polyamide, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, poly(phenylene oxide), poly(phenylene sulfide), polyethylene naphthalene, or mixtures thereof. However, other heat-resistant engineering plastics can be used without particular limitation. Nonwoven materials made of natural and synthetic materials can also be used as the separator substrate.The porous substrate generally has a thickness of 1 to 50 µm and is typically membrane obtained by extrusion and stretching (wet or dry processes) or casting of nonwovens. The porous substrate preferably has a porosity between 5% and 95%. The average pore size (diameter) is preferably between 0.001 and 50 µm, more preferably between 0.01 and 10 µm.

[0087] According to another embodiment, said separator comprises a porous support as described above on which a first layer of inorganic particles as defined in this application is deposited. On said first layer, a second layer comprising said composition according to the present invention is deposited.

[0088] According to an alternative embodiment, said separator does not include a porous support. In this case, said separator consists of the coating as described above and comprising said composition; this coating is deposited directly onto the cathode or anode of the electrochemical device. The absence of a porous support makes it possible to limit the production costs and dimensions of the electrochemical device. In this case, said coating replaces the porous support. In this embodiment, said composition preferably has a porosity of 5 to 95%. The separator coating of the invention offers an excellent compromise of properties for separator coating applications: good adhesion in both dry and wet conditions, good resistance to the electrolyte solvent(s) characterized by good integrity and moderate swelling. Electrode

[0089] This composition can also be used as a binder for an electrode, preferably for a cathode. The electrode comprises this composition of the present invention, a conductive agent, and an active material.

[0090] In a preferred embodiment, the electrode has the following mass composition:

[0091] a. 50% to 99.9% active material, preferably 50% to 99%

[0092] b. 25% to 0% of conducting agent, preferably 25% to 0.5%,

[0093] c. 25% to 0.05% of said composition according to the invention, preferably 25% to 0.5 %,

[0094] d. 0% to 5% of at least one additive chosen from the group consisting of a plasticizer, an ionic liquid, a dispersing agent for a conductive additive, and a flow-aiding auxiliary agent; the sum of all these percentages being 100%.

[0095] The conductive agents in the electrode are composed of one or more materials that can improve conductivity. Some examples include carbon blacks such as acetylene black, Ketjen black; carbon fibers, such as a carbon nanotube, a carbon nanofiber, a carbon fiber by vapor phase growth; metal powders such as SUS powder, and aluminum powder.

[0096] Active materials are materials that are capable of storing and releasing lithium ions.

[0097] In a preferred embodiment, said electrode is a negative electrode. In particular, for a negative electrode, said active material is selected from the group consisting of a lithium alloy, a metal oxide, a carbon material such as graphite or hard carbon, silicon, a silicon alloy and Li4TiO12. The shape of the active material of the negative electrode is not particularly limited but is preferably particulate.

[0098] In another preferred embodiment, said electrode is a positive electrode. Preferably, for a cathode, said active material is chosen from the group consisting of LiCoO2, Li(Ni, Co, Al)O2, Li(l+ x), NiaMnbCoc (x represents a real number of 0 or more, a = 0.8, 0.6, 0.5, or 1 / 3, b = 0.1, 0.2, 0.3, or 1 / 3, c = 0.1, 0.2, or 1 / 3), LiNiO2, LiMn2O4, LiCoMnO4, Li3NiMn3O3, Li3Fe2(PO4)3, Li3V2(PO4)3, a LiMn spinel substituted by a different element having a composition represented by Ll+xMn2-x-yMyO4, M representing at least one metal chosen from Al, Mg, Co, Fe, Ni, and Zn, x and y independently representing a real number between 0 and 2, Lithium titanate LixTiOy - where x and y independently represent a real number between 0 and 2, and a lithium metal phosphate having a composition represented by LiMPO4, where M represents Fe, Mn, Co, or Ni. Furthermore, the surface of each of the materials described above can be coated.The coating material is not particularly limited as long as it has lithium ion conductivity and contains a material capable of being maintained as a coating layer on the surface of the active material. Examples of coating materials include LiNbO3, Li4Ti5O12, and Li3PO4. The shape of the active cathode material is not particularly limited but is preferably particulate.

[0099] Said electrode can be prepared by a process with or without solvent. Said process comprising the following steps:

[0100] - mixture of the active charge, of said composition according to the invention, of the charge conductive and any additives using a process that makes it possible to obtain an electrode formulation applicable to a metallic support by a solvent-free process or in the presence of a solvent;

[0101] - deposition of said electrode formulation onto the metallic substrate by a process without solvent or in the presence of a solvent to obtain a Li-ion battery electrode,

[0102] - optionally a solvent evaporation step; and

[0103] - the consolidation of said electrode by a heat treatment (application of a temperature up to 50°C above the polymer melting temperature, without mechanical pressure), and / or thermo-mechanical treatment such as calendering or thermo-compression.

[0104] A "solvent-free" process is understood to mean a process which does not require a residual solvent evaporation step downstream of the deposition step.

[0105] When a solvent is used, it may be water or an organic solvent, in particular a polar organic solvent having a higher dipole moment at 1.5 Debye. By organic solvent, we can mention without limitation N-methylpyrrolidone, dimethylformamide, dimethylacetamide, N,N-dimethylaminopropylamine, tetrahydrofuran, dimethyl sulfoxide, acetone, methylethylketone, cyclohexanone, gamma-butyrolactone and gamma-valerolactone.

[0106] As solvent-free mixing processes for the different constituents of the electrode formulation, the following may be mentioned without being exhaustive: stirring, air jet mixing, high shear mixing, V-mixer mixing, screw mass mixer mixing, double cone mixing, drum mixing, conical mixing, double Z-arm mixing, fluidized bed mixing, planetary mixer mixing, mechano-fusion mixing, extrusion mixing, calendering mixing, grinding mixing.

[0107] As another mixing method, we can mention mixing methods using a liquid as Skin such as spray drying (co-atomization or "spray drying") or a method of spraying a liquid containing the binder and / or the conductive filler onto a bed of fluidized powder of the active filler.

[0108] The metal supports for the electrodes are generally made of aluminum for the cathode and copper for the anode. The metal supports may be surface-treated and have a conductive primary layer 5 µm or more thick. The supports may also be woven or nonwoven carbon fiber. The electrode is consolidated by heat treatment through a furnace, under an infrared lamp, in a calender with heated rollers, or in a platen press. Another alternative is a two-step process. First, the electrode undergoes heat treatment in a furnace, under an infrared lamp, or in contact with unpressurized heated plates. Then, a compression step at room temperature or under heat is carried out using a calender or a platen press.This step allows the electrode's porosity to be adjusted and improves adhesion to the metallic substrate. Examples

[0109] Three samples of polymers Al, A2, and A3 were tested. All three polymers Al, A2, and A3 are copolymers of vinylidene fluoride with hexafluoropropylene, comprising a carboxylic acid functional group and exhibiting a melt viscosity of 74.25 kP measured at 230°C and a shear rate of 100 s⁻¹ measured according to ASTM D3835. In all three cases, the hexafluoropropylene content is 4.5% by weight. The size distribution of the three samples is shown below in Table 1.

[0110] [Tables 1] Dv99 Dv90 DvlO Al (invention) 25.5 pm 12.8 pm 3.1 pm A2 (invention) 39.7 pm 23.5 pm 4.6 pm A3 (comparative) 90.0 pm 50.2 pm 9.2 pm

[0111] From these three samples in powder form, separator coatings were prepared according to the protocol below. For each coating, the adhesion and Gurley value were measured and reported as a function of the copolymer loading used (hereinafter "loading") to prepare the separators. In the tests carried out with sample A1, the loading was 1.2 g / m². In the tests carried out with sample A2, the loading was 1.6 g / m². In the tests carried out with sample A3, the loading was 2.8 g / m².

[0112] Preparation of redispersed powder compositions

[0113] The samples in powder form (100g) and the dispersant (BYK-21486, 2g) are added to a CMC solution (Nippon Paper F04HC, 4.5g in 900g of deionized water), then the powder is dispersed and optionally deagglomerated using a Filmix mixer operated at 10m / s and 20°C for 1h. The dispersion is then mixed with a binder (BYK-LPC-22346, 6g) and a wetting agent (BYK-LPX-20990, 1.8g), and then homogenized with a magnetic stirrer at 1000 rpm for 20min.

[0114] Measurement of particle size distribution

[0115] The specific particle diameters D10, D90, and D99 represent volumetric average diameter values ​​at 10%, 90%, and 99%, respectively, of the cumulative volume in the particle size distribution, measured with a Microtrac S3500 bluewave analyzer using water as the dispersion medium. Analysis can be performed directly on redispersed powder compositions. To analyze the powder, the following protocol is followed: 0.5 g of powder is placed in a 100 mL container with 2 mL of surfactant (10% Triton X-100) and 60 mL of demineralized water. The mixture is stirred with a magnetic stir bar for 10 min at 200 rpm and then for 5 min in an ultrasonic bath. The mixture is analyzed with a Microtrac S3500 bluewave particle size analyzer in wet mode. Separator Coating

[0116] This formulation is then applied to a Celgard® C210 SP separator using a coating bar equipped with a 50 µm opening squeegee and at a speed of 30 mm / s. The coated separator is dried at 60°C for 5 min. Weight

[0117] The weight of the deposited coating is determined using a precision balance by weighing 24 mm diameter die-cut discs, by the difference between the coated separator and the bare separator. Dry adhesion

[0118] Two separator samples are joined with their coated faces in contact using a roller press operated at 90°C, 1.5 MPa, 2.4 m / min. From this joint, a 22.5 cm strip is cut, one face of which is then adhered to a 3 x 10 cm aluminum plate with double-sided tape. At one end of the sample, the double layer of separators is peeled back by hand to a depth of approximately 5 mm. The sample is then placed in the tensile test at 180° with this peeled section of the separator in one jaw and the aluminum plate in the other jaw. The peeling force is measured at 50 mm / min, then normalized to the sample width and adjusted by the coating basis weight. Gurley Measurement

[0119] The Gurley permeability (Gurley 41 ION densometer with auto-timer 4320EN) of each coated separator is measured, then the permeability of the support (measured at 415sec / 100cc) is subtracted to obtain the Gurley permeability value of the coating, which is then normalized by the coating weight.

[0120] The results are presented in Table 2 below.

[0121] [Tables2] Adhesion / loading Gurley (dry / 100 ml) / loading Al (invention) 0.67 27.8 A2 (invention) 0.43 14.8 A3 (comparative) 0.25 2.96

[0122] As demonstrated by the examples above, the use of a composition according to the present invention makes it possible to obtain better adhesion while maintaining an ionic conductivity acceptable for the intended applications. The selection of a polymer having a particular size distribution as mentioned in this application offers a significant advantage over a polymer with a size distribution that is too large or too heterogeneous.

Claims

Demands

1. Use in the coating of a separator for an electrochemical device or in an electrode binder of a powder composition comprising a PI polymer including monomeric units derived from a MO monomer being vinylidene fluoride or monomeric units derived from a monomer M2 of formula R'R2C=C(R3)C(O)R in which the substituents R1, R2 and R3 are independently selected from the group consisting of H and Ci-C5 alkyl; R is selected from the group consisting of -NHC(CH3)2CH2C(O)CH3 or -OR' with R' selected from the group consisting of H and CrCi8 alkyl optionally substituted by one or more -OH group(s) or a five- or six-membered heterocycle comprising at least one nitrogen atom in its cyclic chain; or a mixture of said MO or M2 monomeric units;characterized in that said PI polymer has a particle size distribution Dv99 less than or equal to 89 pm and a particle size distribution DvlO greater than or equal to 2.0 pm.;

2. Use according to the preceding claim characterized in that said PI polymer is a homopolymer of vinylidene fluoride or a copolymer comprising monomeric units derived from vinylidene fluoride and monomeric units derived from a monomer M1 selected from the group consisting of vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, trifluoropropenes, tetrafluoropropenes, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropenes, perfluoroalkylvinyl ethers, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoroethylene and chlorotrifluoropropene or a mixture thereof; or a copolymer comprising monomeric units derived from vinylidene fluoride and monomeric units derived from a monomer M2 as defined in the preceding claim.

3. Use according to the preceding claim characterized in that said monomer Ml is hexafluoropropylene.

4. Use according to any one of the preceding claims 2 or 3 characterized in that the mass content of said monomer Ml in said polymer PI is between 0.5% and 15% on a basis of the total weight of said polymer PI or the mass content of said monomer M2 in said polymer PI is between 0.01% and 10% on the basis of the total weight of said polymer PI.

5. Use according to any one of the preceding claims 2 to 4 characterized in that the molten viscosity of said PI polymer is greater than or equal to 60 kP at 230°C and at a shear rate of 100 s-1 measured according to ASTM D3835.

6. Use according to any one of the preceding claims 2 to 5 characterized in that said PI polymer also comprises a functional group selected from the group consisting of carboxylic acid, carboxylic acid anhydride, carboxylic acid esters, epoxy, amide, hydroxyl, carbonyl, mercapto, sulfide, oxazoline, phenolic, ester, ether, siloxane, sulfonic, sulfuric, phosphoric, and phosphonic groups; preferably carboxylic acid, carboxylic acid anhydride, carboxylic acid esters, hydroxyl, phosphoric, and phosphonic.

7. Use according to claim 1 characterized in that said PI polymer contains monomeric units derived from a monomer M2 selected from the group consisting of acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-dodecyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, lauryl acrylate, n-octyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, methyl acrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, methacrylate isobutyl, t-butyl methacrylate, n-dodecyl methacrylate, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate,n-Octyl methacrylate, ureido methacrylate and mixtures thereof.

8. Use according to any one of the preceding claims characterized in that said PI polymer has a particle size distribution Dv90 less than or equal to 50 pm.

9. Use according to any one of the preceding claims characterized in that said PI polymer is free of fluoro surfactants.

10. Separator for electrochemical device selected from the group: Li-ion, capacitor, double-layer electric capacitor, and membrane electrode assembly (MEA) for fuel cell, said separator comprising a porous support and said composition as defined in any one of the preceding claims 1 to 9.

11. Secondary Li-ion battery comprising an anode, a cathode and a separator, wherein said separator is according to the preceding claim.

12. Li-ion battery binder comprising said composition as defined in any one of the preceding claims 1 to 9.

13. Electrode for lithium-ion battery comprising a metallic collector of which at least one face is covered with a substrate layer containing an active substance and a binder, characterized in that said binder is according to the preceding claim.

14. Secondary Li-ion battery comprising an anode, a cathode and a separator, wherein the anode or the cathode is an electrode according to the preceding claim.

15. Powder composition comprising a PI polymer comprising monomeric units derived from a MO monomer being vinylidene fluoride characterized in that said PI polymer has a particle size distribution Dv99 less than or equal to 89 pm, a particle size distribution DvlO greater than or equal to 2.9 pm and a particle size distribution Dv90 less than 30 pm.

16. Composition according to the preceding claim characterized in that said PI polymer is a homopolymer of vinylidene fluoride or a copolymer comprising monomeric units derived from vinylidene fluoride and monomeric units derived from a monomer M1 selected from the group consisting of vinyl fluoride, tetrafluoroethylene, hexafluoropropylene, trifluoropropenes, tetrafluoropropenes, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropenes, perfluoroalkylvinyl ethers, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoroethylene, and chlorotrifluoropropene or a mixture thereof; or a copolymer comprising monomeric units derived from vinylidene fluoride and monomeric units derived from a monomer M2 of formula R'R2C=C(R3)C(O)R in which the substituents R1, R2 and R3 are independently selected from the group consisting of H and Ci-C5 alkyl; R is selected from the group consisting of -NHC(CH3)2CH2C(O)CH3 or -OR' with R' selected from the group consisting of H and CrCi8 alkyl optionally substituted by one or more -OH group(s) or a five- or six-membered heterocycle comprising at least one nitrogen atom in its cyclic chain.

17. Powder composition comprising a PI polymer, being a copolymer comprising monomeric units derived from vinylidene fluoride and monomeric units derived from hexafluoropropylene, characterized in that said PI polymer has a particle size distribution Dv99 less than or equal to 89 pm, a particle size distribution DvlO greater than or equal to 2.9 pm and a particle size distribution Dv90 less than or equal to 40 pm.

18. A powder composition comprising a PI polymer including monomeric units derived from a monomer M2 of formula R'R2C=C(R3)C(O)R in which the substituents R1, R2 and R3 are independently selected from the group consisting of H and Ci-C5 alkyl; R is selected from the group consisting of -NHC(CH3)2CH2C(O)CH3 or -OR' with R' selected from the group consisting of H and Ci-Ci8 alkyl optionally substituted by one or more -OH group(s) or a five- or six-membered heterocycle comprising at least one nitrogen atom in its cyclic chain characterized in that said PI polymer has a particle size distribution Dv99 less than or equal to 89 pm and a particle size distribution DvlO greater than or equal to 2.0 pm.

19. Composition according to the preceding claim characterized in that said polymer PI contains monomeric motifs derived from a monomer M2 selected from the group consisting of acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-Butyl acrylate, n-dodecyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, lauryl acrylate, n-octyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, methyl acrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-Butyl methacrylate, isobutyl methacrylate, t-Butyl methacrylate, n-dodecyl methacrylate, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, ureido methacrylate and mixtures thereof.