Binders for dry electrode preparation

Abstract

The invention relates to a dry composition comprising at least one active material, at least one binder, optionally at least one electrically conductive agent, characterized in that the at least one binder comprises a fluoropolymer and a polyamide thermoplastic polymer or a polyether block amide or a mixture thereof.

Description

Technical Field

[0001] This invention generally relates to the field of energy storage in lithium-ion batteries. More specifically, this invention relates to a composition for a dry-coated electrode for a lithium-ion battery. Another aspect of the invention is a method for manufacturing an electrode using said composition. The invention also relates to a lithium-ion battery manufactured by incorporating said electrode. Background Technology

[0002] A basic lithium-ion battery, or lithium battery, consists of an anode (during discharge) and a cathode (also during discharge). The anode and cathode are typically made of lithium intercalation compounds of the metal oxide type, such as LiMn2O4, LiCoO2, or LiNiO2, with an electrolyte that conducts lithium ions inserted between the anode and cathode.

[0003] Rechargeable or secondary batteries are more advantageous than primary (non-rechargeable) batteries because the related chemical reactions occurring at the positive and negative electrodes are reversible. The electrodes of a secondary battery can be regenerated several times by applying charge. Many advanced electrode systems have been developed to store charge. Simultaneously, considerable effort has been devoted to developing electrolytes that can improve the capacity of electrochemical batteries.

[0004] In itself, the electrode typically includes at least one current collector on which a composite material is deposited in the form of a film. The composite material consists of a so-called active material (because it is electrochemically active relative to lithium), a polymer acting as a binder, plus one or more electronically conductive additives, typically carbon black or acetylene black, and optionally a surfactant.

[0005] Binders are often categorized as inactive components because they do not directly contribute to battery capacity. However, their crucial role in electrode fabrication and their considerable impact on the electrochemical performance of the electrode have been extensively described. The main relevant physical and chemical properties of binders are thermal stability, chemical and electrochemical stability, tensile strength (strong adhesion and cohesion), and flexibility. The primary purpose of using binders is to form a stable network (cohesion) of the solid components of the electrode (i.e., the active material and the conductive agent). Furthermore, the binder must ensure close contact (adhesion) between the composite electrode and the current collector.

[0006] Polyvinylidene fluoride (PVDF) is used as a binder in lithium-ion batteries due to its excellent electrochemical stability, good bonding ability, and high adhesion to electrode materials and current collectors. However, PVDF is only soluble in certain organic solvents, such as N-methylpyrrolidone (NMP), which is volatile, flammable, explosive, and highly toxic, leading to serious environmental problems. In practice, the wet slurry method disperses the active material and binder in a liquid solution. The liquid used is typically an organic solvent or water. The dispersion is cast onto a current collector and then dried in a high-temperature oven to prepare the electrode. This method requires a large amount of energy to dry the liquid components of the slurry, and the organic solvents also generate harmful vapors, necessitating specialized equipment to prevent their release into the environment.

[0007] Compared to conventional wet suspension electrode manufacturing methods, dry (solvent-free) manufacturing processes are simpler; these methods eliminate the emission of volatile organic compounds and offer the possibility of manufacturing electrodes with greater thickness (>120 μm), ultimately resulting in energy storage devices with higher energy densities. Changes in production technology have little impact on the active materials of the electrodes; however, the polymer additives responsible for the mechanical integrity of the electrodes must adapt to the new manufacturing conditions.

[0008] US 2019 / 0305316 discloses dry electrode films comprising a non-fibrillable binder with a certain particle size, and a method for obtaining films with sufficient flexibility to handle roll-to-roll processes by using a fibrillable binder. However, in addition to dispersing the components, the fibrillable binder requires additional shear. This consumes high energy and is destructive to the active material. Dry electrode films comprising an elastic polymer binder are also known from US 2020 / 0313193, wherein the dry electrode film is independent and contains at most a non-significant amount of polytetrafluoroethylene. US 2020 / 0313193 primarily discloses polyethylene as an elastic polymer binder, whose electrochemical stability is insufficient for use as the cathode and anode of lithium-ion secondary batteries.

[0009] Therefore, there is still a need to develop new electrode compositions for Li-ion batteries that can be processed without the use of organic solvents. Summary of the Invention

[0010] In a first aspect, the present invention provides a dry composition comprising at least one active material, at least one binder, and optionally at least one conductive agent, characterized in that the at least one binder comprises a fluoropolymer and a polyamide thermoplastic polymer or a polyether block amide or a mixture thereof. It has been found that the binder according to the invention allows for the dry preparation of electrodes with improved coulombic efficiency. Technical effects on electrode efficiency can be obtained by adding a polyamide thermoplastic polymer to a binder comprising a fluoropolymer.

[0011] Preferably, in the dry composition, all components are in powder form.

[0012] In one embodiment, the particle size distribution Dv50 of the polyamide thermoplastic polymer is less than 30 μm.

[0013] In one embodiment, the fluoropolymer is a fibrillable fluoropolymer, preferably comprising repeating units derived from monomer M1a, which is tetrafluoroethylene.

[0014] In one embodiment, the particle size distribution Dv50 of the fibrillable fluoropolymer is less than 1000 μm.

[0015] In one embodiment, the fluoropolymer is a non-fibrillable polymer; preferably comprising repeating units derived from a monomer M1a selected from: vinylidene fluoride, trifluoroethylene, 1,2-difluoroethylene, perfluoro(alkyl vinyl) ether, perfluoro(1,3-m-dioxacyclopentene), perfluoro(2,2-dimethyl-1,3-m-dioxacyclopentene), monomers of the formula CF2=CFOCF2CF(CF3)OCF2CF2X, wherein X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, monomers of the formula CF2=CFOCF2CF2SO2F, and monomers of the formula F(CF2). n The monomer of CH2OCF=CF2, where n is 1, 2, 3, 4 or 5, Equation R 1 The monomer of CH2OCF=CF2, where R 1 It is hydrogen or F (CF2). m And m is 1, 2, 3 or 4, Equation R 2 The monomer of OCF=CH2, where R 2 Let F(CF2) be the value. p And p is 1, 2, 3 or 4, perfluorobutylethylene, 3,3,3-trifluoropropylene, tetrafluoropropylene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropylene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropylene, ethylene and 2-trifluoromethyl-3,3,3-trifluoro-1-propylene or mixtures thereof; in particular, the fluoropolymer comprises repeating units derived from vinylidene fluoride.

[0016] In one embodiment, the particle size distribution Dv50 of the non-fibrillable fluoropolymer is less than 100 μm.

[0017] In one embodiment, the polyamide thermoplastic polymer is selected from PA 6, PA 11, PA 12, PA 6.10, PA 6.12, PA 6.14, PA 6.18, PA 10.10, PA 10.12, copolyamides, and mixtures thereof.

[0018] In one embodiment, the polyether block amide is a copolymer having amide units (Ba1) and polyether units (Ba2), wherein the amide units (Ba1) correspond to aliphatic repeating units selected from units obtained from at least one amino acid or from at least one lactam, or units X·Y obtained by the following condensation polymerization:

[0019] - At least one diamine, preferably selected from straight-chain or branched aliphatic diamines or mixtures thereof, and

[0020] - At least one carboxylic acid diacid, preferably selected from: straight-chain or branched aliphatic diacids, or mixtures thereof.

[0021] The diamine and the diacid contain 4 to 36 carbon atoms, advantageously 6 to 18 carbon atoms; the polyether unit (Ba2) is particularly derived from at least one polyalkylene ether polyol, especially polyalkylene ether diol.

[0022] In one embodiment, the at least one active material is selected from the following: LiCoO2, Li(Ni,Co,Al)O2, Li (1+x) Ni a Mn b Co c (x represents a real number 0 or greater, a = 0.9, 0.8, 0.6, 0.5 or 1 / 3, b = 0.05, 0.1, 0.2, 0.3 or 1 / 3, c = 0.05, 0.1, 0.2 or 1 / 3), LiNiO2, LiMn2O4, LiCoMnO4, Li3NiMn3O3, Li3Fe2(PO4)3, Li3V2(PO4)3, possessing properties derived from Li (1+x) Mn (2-x-y) M y O4 represents LiMn spinel with different elemental substitutions, where M represents at least one metal selected from Al, Mg, Co, Fe, Ni, and Zn, and x and y independently represent real numbers between 0 and 2, lithium titanate Li x TiO y , where x and y independently represent real numbers between 0 and 2, and have a lithium metal phosphate composition represented by LiMPO4, and M represents Fe, Mn, Co or Ni.

[0023] In one embodiment, the at least one active material is selected from lithium metal, lithium alloys, metal oxides, carbon materials such as graphite or hard carbon, silicon, silicon alloys, and Li4Ti5O. 12 .

[0024] In one embodiment, the dry composition has the following mass composition:

[0025] a. 50% to 99.9%, preferably 50% to 99%, of the at least one active material,

[0026] b. 0% to 25%, preferably 0.5% to 25% of the at least one conductive agent,

[0027] c. 0.1% to 25%, preferably 0.5% to 25% of the at least one adhesive,

[0028] d. 0% to 5% of at least one additive selected from plasticizers, ionic liquids, dispersants for conductive additives, and flow aids;

[0029] The sum of all these percentages is 100%.

[0030] In another aspect, the present invention relates to a membrane comprising, preferably composed of, a dry composition according to the invention.

[0031] In one embodiment, the active material included in the dry composition is selected from lithium metal, lithium alloys, metal oxides, carbon materials such as graphite or hard carbon, silicon, silicon alloys, and Li4Ti5O. 12 At this point, the membrane has a density of less than 1.65 g / cc. This density allows for higher capacity and rate performance.

[0032] In another embodiment, the film density is greater than 1.65 g / cc when the active material contained in the dry composition is selected from the following: LiCoO2, Li(Ni,Co,Al)O2, Li (1+x) Ni a Mn b Co c (x represents a real number 0 or greater, a = 0.9, 0.8, 0.6, 0.5, or 1 / 3, b = 0.05, 0.1, 0.2, 0.3, or 1 / 3, c = 0.05, 0.1, 0.2, or 1 / 3), LiNiO2, LiMn2O4, LiCoMnO4, Li3NiMn3O3, Li3Fe2(PO4)3, Li3V2(PO4)3, possessing properties derived from Li (1+x) Mn (2-x-y) M y O4 represents LiMn spinel with different elemental substitutions, where M represents at least one metal selected from Al, Mg, Co, Fe, Ni, and Zn, and x and y independently represent real numbers between 0 and 2, lithium titanate Li x TiO y , where x and y independently represent real numbers between 0 and 2, and lithium metal phosphates with a composition represented by LiMPO4, and M represents Fe, Mn, Co or Ni.

[0033] In another aspect, the present invention relates to a dry-coated electrode comprising a dry composition according to the invention coated onto a substrate by a solvent-free method.

[0034] In another aspect, the present invention relates to a lithium-ion battery comprising a positive electrode, a negative electrode and a separator, wherein at least one of these electrodes is a dry-coated electrode according to the present invention.

[0035] In another aspect, the present invention relates to a method for preparing a dry-coated electrode according to the invention, the method comprising the steps of: dry mixing at least one active material, at least one binder, and optionally at least one conductive agent to provide an electrode formulation; processing the electrode formulation to form a self-supporting film; and laminating the self-supporting film onto a substrate to form a laminated film coated on the substrate.

[0036] In another aspect, the present invention relates to a method for preparing a dry-coated electrode according to the invention, the method comprising the steps of: dry mixing at least one active material, at least one binder, and optionally at least one conductive agent to provide an electrode formulation; depositing the electrode formulation onto a substrate by a solvent-free method to obtain a lithium-ion battery electrode; and consolidating the electrode by thermomechanical treatment at a temperature of 15 °C to 300 °C. Detailed Implementation Plan

[0037] dry composition

[0038] In a first aspect of the invention, a dry composition is provided. The dry composition comprises at least one active material and at least one binder. The at least one binder comprises a fluoropolymer and a polyamide thermoplastic polymer. In the dry composition, the at least one binder and the at least one active material are in powder form.

[0039] In the dry composition, the weight ratio between the fluoropolymer and the polyamide thermoplastic polymer is 99 / 1 to 1 / 99, advantageously 90 / 10 to 10 / 90, preferably 80 / 20 to 20 / 80, and more preferably 70 / 30 to 30 / 70.

[0040] Dv50 is the particle size at the 50th percentile (by volume) of the cumulative size distribution of the particles. This parameter is determined by laser particle size analysis. Measurements are performed using a Malvern INSITEC System particle size analyzer. This is accomplished in a dry process using laser diffraction on the powder with a 100 mm focus. This applies to all Dv50 values ​​described in this specification.

[0041] Dv90 is the particle size at the 90th percentile (by volume) of the cumulative size distribution of the particles. This parameter is determined by laser particle size analysis. Measurements are performed using a Malvern INSITEC System particle size analyzer. This is accomplished in a dry process using laser diffraction on the powder with a 100 mm focus. This applies to all Dv90 values ​​described in this specification.

[0042] The at least one adhesive is in powder form. Specifically, the powder has a particle size distribution with a Dv90 less than or equal to 7500 μm, advantageously less than or equal to 7000 μm, preferably less than or equal to 6500 μm, more preferably less than or equal to 6000 μm, particularly less than or equal to 5500 μm, and even more particularly less than or equal to 5000 μm. Advantageously, the adhesive has a particle size distribution with a Dv90 less than or equal to 4500 μm, preferably less than or equal to 4000 μm, preferably less than or equal to 3500 μm, particularly less than or equal to 3000 μm, even more particularly less than or equal to 2500 μm, preferably less than or equal to 2000 μm, less than or equal to 1500 μm, preferably less than or equal to 1000 μm, and less than or equal to 500 μm.

[0043] The dry composition may optionally contain at least one conductive additive. The conductive additive comprises one or more materials that can improve conductivity. Some examples include carbon black, such as acetylene black and Ketjen black; carbon fibers, such as carbon nanotubes, carbon nanofibers, and vapor-grown carbon fibers; and metal powders, such as SUS powder and aluminum powder.

[0044] As described above, the dry composition contains at least one active material.

[0045] If the electrode to be prepared is a negative electrode, the active material can be selected from lithium metal, lithium alloys, metal oxides, carbon materials such as graphite or hard carbon, silicon, silicon alloys, and Li4Ti5O. 12 Or a mixture thereof.

[0046] Alternatively, if the electrode to be prepared is a positive electrode, the active material can be selected from LiCoO2, Li(Ni,Co,Al)O2, Li (1+x) Ni a Mn b Co c (x represents a real number 0 or greater, a = 0.9, 0.8, 0.6, 0.5, or 1 / 3, b = 0.05, 0.1, 0.2, 0.3, or 1 / 3, c = 0.05, 0.1, 0.2, or 1 / 3), LiNiO2, LiMn2O4, LiCoMnO4, Li3NiMn3O3, Li3Fe2(PO4)3, Li3V2(PO4)3, possessing properties derived from Li(1+x) Mn (2-x-y) M y O4 represents LiMn spinel with different elemental substitutions, where M represents at least one metal selected from Al, Mg, Co, Fe, Ni, and Zn, and x and y independently represent real numbers between 0 and 2, lithium titanate Li x TiO y , where x and y independently represent real numbers between 0 and 2, and lithium metal phosphates having a composition represented by LiMPO4, and M representing Fe, Mn, Co or Ni, or mixtures thereof.

[0047] In addition, the surfaces of the above-mentioned materials can be coated. There are no particular limitations on the coating materials, as long as they possess lithium-ion conductivity and contain materials that can be retained on the surface of the active material in the form of a coating layer. Examples of coating materials include LiNbO3 and Li4Ti5O3. 12 Li3PO4.

[0048] The shape of the active substance is not particularly limited, but it is preferably particulate.

[0049] As described above, it has been surprisingly found that the adhesive according to the invention allows for the dry fabrication of electrodes with improved coulombic efficiency. Adhesion is also improved by using the adhesive of the invention compared to known adhesives.

[0050] In one embodiment, the dry composition has the following mass composition:

[0051] a. 50% to 99.9%, preferably 50% to 99%, of the at least one active material,

[0052] b. 0% to 25%, preferably 0.5% to 25%, of the at least one conductive agent.

[0053] c. 0.1% to 25%, preferably 0.5% to 25% of the at least one adhesive,

[0054] d. 0% to 5% of at least one additive selected from plasticizers, ionic liquids, dispersants for conductive additives, and flow aids;

[0055] The sum of all these percentages is 100%.

[0056] Fluoropolymers

[0057] The term "fluoropolymer" refers to a polymer formed by the polymerization of at least one fluorinated monomer, and it includes thermoplastic homopolymers, copolymers, terpolymers, and more advanced polymers. "Thermoplastic" here should be understood to mean an inelastic polymer. An elastic polymer is defined as a polymer that can be stretched to twice its initial length at ambient temperature and, after stress release, rapidly returns to its initial length within approximately 10%, as noted by ASTM in Special Technical Publication, No. 184.

[0058] According to a preferred embodiment, the fluoropolymer contains repeating units derived from at least one fluorinated monomer M1a in its chain, the fluorinated monomer M1a being selected from compounds containing a vinyl group capable of opening for polymerization and containing at least one fluorine atom, fluoroalkyl group or fluoroalkoxy group directly attached to the vinyl group.

[0059] Preferably, the fluoropolymer comprises repeating units derived from a monomer M1a selected from: vinyl fluoride; vinylidene fluoride (VDF); 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-m-dioxacyclopentene); perfluoro(2,2-dimethyl-1,3-m-dioxacyclopentene) (PDD); products of the formula CF2=CFOCF2CF(CF3)OCF2CF2X, wherein X is SO2F, CO2H, CH2OH, CH2OCN, or CH2OPO3H; products of the formula CF2=CFOCF2CF2SO2F; and products of the formula F(CF2). n The product of CH2OCF=CF2, where n is 1, 2, 3, 4 or 5; formula R 1 The product of CH2OCF=CF2, in which R 1 It can be hydrogen or F (CF2). m m is 1, 2, 3 or 4; Equation R 2 The product of OCF=CH2, in which R 2 Let F(CF2) be the value. pAnd p is 1, 2, 3, or 4; perfluorobutylethylene (PFBE); trifluoropropylene, tetrafluoropropylene, hexafluoroisobutylene, perfluorobutene, pentafluoropropylene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropylene, and 2-trifluoromethyl-3,3,3-trifluoro-1-propene or mixtures thereof. Trifluoropropylene includes 3,3,3-trifluoropropylene. Tetrafluoropropylene includes 2,3,3,3-tetrafluoropropylene and 1,3,3,3-tetrafluoropropylene. Pentafluoropropylene includes 1,1,3,3,3-pentafluoropropylene or 1,2,3,3,3-pentafluoropropylene. Chlorofluoroethylene may refer to 1-chloro-1-fluoroethylene or 1-chloro-2-fluoroethylene. The isomer 1-chloro-1-fluoroethylene is preferred. Chlorotrifluoropropylene is preferably 1-chloro-3,3,3-trifluoropropylene or 2-chloro-3,3,3-trifluoropropylene.

[0060] In the fluoropolymer, the mass percentage of the repeating unit M1a is at least 50%, preferably at least 60%, preferably greater than 70%, and advantageously greater than 80%.

[0061] In one particular embodiment, the fluoropolymer is a fibrillable fluoropolymer. The fibrillable fluoropolymer comprises repeating units derived from monomer M1a, which is tetrafluoroethylene; preferably, it comprises at least 60% or at least 70% or at least 80% or at least 90% or at least 95% molar repeating units derived from monomer M1a, which is tetrafluoroethylene. Preferably, the particle size distribution Dv50 of the fibrillable fluoropolymer is less than 1000 μm, more preferably less than 750 μm, most preferably less than 500 μm, particularly less than 250 μm, more particularly less than 100 μm, and most particularly less than 50 μm. The fibrillable fluoropolymer can be used alone or in combination with other possible fibrillable adhesives such as ultra-high molecular weight polypropylene, polyethylene, copolymers thereof, or polymer blends.

[0062] Specifically, the fibrillable fluoropolymer comprises repeating units derived from tetrafluoroethylene monomer M1a, and optionally repeating units derived from fluorinated monomer M1b capable of copolymerizing with tetrafluoroethylene, or repeating units derived from non-fluorinated monomer M1c or a mixture of M1b and M1c. The repeating unit is derived from a monomer M1b selected from the following: ethylene fluoride; trifluoroethylene (VF3); chlorotrifluoroethylene (CTFE); 1,2-difluoroethylene; vinylidene fluoride; 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-m-dioxacyclopentene); perfluoro(2,2-dimethyl-1,3-m-dioxacyclopentene) (PDD); products of the formula CF2=CFOCF2CF(CF3)OCF2CF2X, where X is SO2F, CO2H, CH2OH, CH2OCN, or CH2OPO3H; products of the formula CF2=CFOCF2CF2SO2F; and products of the formula F(CF2). n The product of CH2OCF=CF2, where n is 1, 2, 3, 4 or 5; formula R 1 The product of CH2OCF=CF2, in which R 1 It can be hydrogen or F (CF2). m m is 1, 2, 3 or 4; Equation R 2 The product of OCF=CH2, in which R 2 Let F(CF2) be the value. p And p is 1, 2, 3 or 4; perfluorobutylethylene (PFBE); trifluoropropylene, tetrafluoropropylene, hexafluoroisobutylene, perfluorobutene, pentafluoropropylene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropylene and 2-trifluoromethyl-3,3,3-trifluoro-1-propylene or mixtures thereof. The nonfluorinated monomer M1c is defined below.

[0063] Specifically, the fibrillable fluoropolymer is poly(tetrafluoroethylene) (PTFE), which is composed of repeating units derived from the tetrafluoroethylene monomer M1a.

[0064] In another particular embodiment, the fluoropolymer is a non-fibrillable polymer. Preferably, the fluoropolymer is non-fibrillable when it comprises repeating units derived from a monomer M1a selected from: vinylidene fluoride, trifluoroethylene, 1,2-difluoroethylene, perfluoro(alkyl vinyl) ether, perfluoro(1,3-m-dioxacyclopentene); perfluoro(2,2-dimethyl-1,3-m-dioxacyclopentene), monomers of the formula CF2=CFOCF2CF(CF3)OCF2CF2X, wherein X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, monomers of the formula CF2=CFOCF2CF2SO2F, or F(CF2). n The monomer of CH2OCF=CF2, where n is 1, 2, 3, 4 or 5, Equation R 1 The monomer of CH2OCF=CF2, where R 1 It can be hydrogen or F (CF2). m And m is 1, 2, 3 or 4, Equation R 2 The monomer of OCF=CH2, where R 2 Let F(CF2) be the value. p And p is 1, 2, 3 or 4, perfluorobutylethylene, 3,3,3-trifluoropropylene, tetrafluoropropylene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropylene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropylene, ethylene and 2-trifluoromethyl-3,3,3-trifluoro-1-propylene or mixtures thereof. Preferably, the non-fibrillable fluoropolymer comprises at least 50% or at least 60% or at least 70% or at least 80% or at least 90% based on molar amounts of repeating units derived from monomer M1a as defined herein. Preferably, the non-fibrillable fluoropolymer has a particle size distribution Dv50 of less than 100 μm, more preferably less than 75 μm, most preferably less than 50 μm, particularly less than 25 μm, more particularly less than 10 μm, and most particularly less than 5 μm. In particular, the non-fibrillable fluoropolymer comprises at least repeating units derived from monomer M1a, which is vinylidene fluoride. Non-fibrillable fluoropolymers can be homopolymers or copolymers of vinylidene fluoride. According to a particular embodiment, the non-fibrillable fluoropolymer is a vinylidene fluoride homopolymer. Specifically, non-fibrillable fluoropolymers include repeating units derived from vinylidene fluoride monomer M1a and repeating units derived from fluorinated monomer M1b capable of copolymerizing with vinylidene fluoride, or repeating units derived from non-fluorinated monomer M1c or a mixture of both M1b and M1c.

[0065] According to one embodiment, the non-fibrillable fluoropolymer comprises repeating units derived from vinylidene fluoride monomer M1a and repeating units derived from monomer M1b selected from: 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-m-dioxacyclopentene); perfluoro(2,2-dimethyl-1,3-m-dioxacyclopentene) (PDD); products of the formula CF2=CFOCF2CF(CF3)OCF2CF2X, wherein X is SO2F, CO2H, CH2OH, CH2OCN, or CH2OPO3H; products of the formula CF2=CFOCF2CF2SO2F; and products of the formula F(CF2). n The product of CH2OCF=CF2, where n is 1, 2, 3, 4 or 5; formula R 1 The product of CH2OCF=CF2, in which R 1 It can be hydrogen or F (CF2). m And m can be 1, 2, 3 or 4; Equation R 2 The product of OCF=CH2, in which R 2 Let F(CF2) be the value. p And p is 1, 2, 3 or 4; perfluorobutylethylene (PFBE); trifluoropropylene, tetrafluoropropylene, hexafluoroisobutylene, perfluorobutene, pentafluoropropylene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropylene and 2-trifluoromethyl-3,3,3-trifluoro-1-propene or mixtures thereof. Preferably, the non-fibrillable fluoropolymer comprises repeating units derived from vinylidene fluoride monomer M1a and repeating units derived from monomer M1b selected from: fluoroethylene; trifluoroethylene; chlorotrifluoroethylene; 1,2-difluoroethylene, tetrafluoroethylene; hexafluoropropylene; perfluoro(alkyl vinyl) ethers, such as perfluoro(methyl vinyl) ether, perfluoro(ethyl vinyl) ether or perfluoro(propyl vinyl) ether; perfluoro(1,3-m-dioxane); perfluoro(2,2-dimethyl-1, 3-m-Dioxacyclopentene); products of the formula CF2=CFOCF2CF(CF3)OCF2CF2X, where X is SO2F, CO2H, CH2OH, CH2OCN, or CH2OPO3H; products of the formula CF2=CFOCF2CF2SO2F; products of the formula F(CF2)nCH2OCF=CF2, where n is 1, 2, 3, 4, or 5; products of the formula R′CH2OCF=CF2, where R′ is hydrogen or F(CF2). z And z can be 1, 2, 3 or 4; the product of formula R″OCF=CH2, where R″ is F(CF2). zAnd z is 1, 2, 3, or 4; trifluoropropylene, tetrafluoropropylene, hexafluoroisobutylene, perfluorobutene, pentafluoropropylene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropylene, or 2-trifluoromethyl-3,3,3-trifluoro-1-propylene or mixtures thereof. Specifically, the non-fibrillable fluoropolymer comprises repeating units derived from vinylidene fluoride monomer M1a and repeating units derived from monomer M1b selected from: trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, and hexafluoropropylene or mixtures thereof. Based on the total weight of the fluoropolymer, the weight content of monomer M1b in the fluoropolymer can be from 1 wt% to 40 wt%, preferably from 4 wt% to 35 wt%, particularly from 4 wt% to 15 wt%.

[0066] The fluoropolymer, whether fibrillable or nonfibrillable, may also contain components derived from the formula R a R b C=C(R c )C(O)R d The repeating unit of the nonfluorinated monomer M1c, wherein the substituent R a R b and R c Independently selected from H and C1-C5 alkyl groups; R d Selected from -NHC(CH3)2CH2C(O)CH3 or -OR d ', where R d Choose freely between H and C1-C 18 Alkyl, the C1-C 18 Alkyl groups are optionally surrounded by one or more -OH, -CO2H, -SO3H, -PO3H, or -OC(O)R. d "、-C(O)OR d "or a five- or ten-chain heterocyclic substitution containing at least one nitrogen atom in its ring chain; R" d "Selected from: C1646-C ... 1 -C 6 Alkyl or C 6 -C 12 Aryl group. The heterocycle may be saturated, unsaturated, or aromatic. The heterocycle may be monocyclic or bicyclic. The heterocycle may be pyrrole, pyrrolidine, pyridine, piperidine, pyrimidine, pyrazine, 1,4-dihydropyridine, indole, hydroxyindole, indigo, quinoline, isoquinoline, quinazoline, imidazoline, pyrazolidine, 2-pyrrolidone, δ-lactam, succinimide, 2-imidazolidinone, 4-imidazolidinone. The heterocycle may be substituted with one or more C1-C5 alkyl groups. As described above, the alkyl group C1-C5... 18Optionally, it is substituted with the heterocycle. The latter can be bonded to the alkyl chain via a nitrogen atom or any other atom forming the heterocycle. Preferably, the heterocycle is 2-pyrrolidone, δ-lactam, succinimide, 2-imidazolidineone, or 4-imidazolidineone. The monomer M1c may have the formula R a R b C=C(R c )C(O)R d In which the substituent R a R b and R c Independently selected from H and C1-C5 alkyl groups; R d Selected from -NHC(CH3)2CH2C(O)CH3 or -OR d’ , where R d’ Selected from H and C1-C 18 Alkyl, the C1-C 18 The alkyl group may optionally be substituted with one or more of the following groups: -OH, -CO2H, -SO3H, -PO3H, -OC(O)R d” -C(O)OR d” Or a five- or ten-membered heterocycle containing at least one nitrogen atom in its ring chain; R d” Selected from the following: C1-C6 alkyl or C6-C6 alkyl groups optionally substituted with one or more -OH, -CO2H, -SO3H, or -PO3H groups. 12 Aryl group. Preferably, the heterocycle is as defined above, and in particular, the heterocycle is 2-pyrrolidone, δ-lactam, succinimide, 2-imidazolidineone, or 4-imidazolidineone. Preferably, the substituent R... d' The monomer is selected from the following: H, methyl, ethyl, propyl, n-butyl, isobutyl, tert-butyl, n-dodecyl ester, pentyl, isopentyl, hexyl-2-ethylhexyl ester, lauryl ester, and n-octylhydroxyethylhydroxybutylhydroxypropyl, and ureidosubstituted ethyl groups for replacing ethyl groups. In particular, the monomer M1c has the formula R. a R b C=C(R c )C(O)Rd, where the substituent R a and R b It is H; R c It is H or CH3; R d Yes - OR d’ , where R d’The monomer is selected from H, methyl, ethyl, propyl, n-butyl, isobutyl, tert-butyl, hydroxypropyl, hydroxybutyl, 2-pyrrolidone, δ-lactam, succinimide, 2-imidazolium, and 4-imidazolium. More specifically, the M1c monomer can be acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-dodecyl acrylate, pentyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, lauryl acrylate, n-octyl acrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-dodecyl methacrylate, pentyl methacrylate, isoamyl methacrylate, and hexyl methacrylate. 2-Ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, urea methacrylate, monomers having the following formulas: CH2=CH(CO2CH2CH2CO2H), CH2=CH(CO2CH2CH2-OC(O)-CH2CH2CO2H), CH2=CH(CO2CH2CH2CH2-OC(O)-CH2CH2CO2H), CH2=CH(CO2CH(CH3)CH2-OC(O)-CH2CH2CO2H), CH2=CH(CO2CH2CH2-OC(O)-C6H4CO2H), CH2=CH(CO2CH2CH2CH2CH(CO2H)CH2CH2CO2H); and mixtures thereof. Among these, monomers M1c having alkyl groups having 1 to 8 carbon atoms are preferred, and monomers M1c having alkyl groups having 1 to 5 carbon atoms are more preferred. The fluoropolymer may contain one or more repeating units derived from monomers M1c as defined herein. Based on the total weight of the fluoropolymer, the weight content of monomer M1c in the fluoropolymer can be in the range of 0.1 wt% to 10 wt%, particularly from 0.5 wt% to 5 wt%.

[0067] Fluoropolymers, whether fibrillable or non-fibrillable, can be functionalized to improve their adhesion to metals. Therefore, the fluoropolymer may contain repeating units with at least one functional group selected from: carboxylic acids, carboxylic anhydrides, carboxylic esters, epoxy groups such as glycidyl groups, amides, hydroxyl groups, carbonyl groups, mercapto groups, sulfides, oxazolines, phenols, esters, ethers, siloxanes, sulfonic acids, sulfuric acids, phosphoric acids, phosphonic acids; preferably at least one carboxylic acid functional group or hydroxyl group.

[0068] Functional groups can be introduced through a chemical reaction, which can be grafting or copolymerization of a fluoropolymer with a monomer having at least one of the said functional groups and a vinyl functional group capable of copolymerizing with a fluorinated monomer, according to techniques known to those skilled in the art.

[0069] Alternatively, the functional group can be introduced by a chain transfer agent used in the synthesis process. The chain transfer agent can be a polymer with a molecular weight of 20,000 g / mol or less and containing functional groups selected from: carboxylic acids, carboxylic anhydrides, carboxylic esters, epoxy groups (e.g., glycidyl groups), amides, hydroxyl groups, carbonyl groups, mercapto groups, sulfides, oxazolines, phenols, esters, ethers, siloxanes, sulfonic acids, sulfuric acids, phosphoric acids, and phosphonic acids. An example of such a chain transfer agent is an acrylic oligomer. According to a preferred embodiment, the chain transfer agent is an acrylic oligomer with a molecular weight of 20,000 g / mol or less. Alternatively, the functional group can be introduced by an oligomer or polymer compound containing said functional group and mixed with the fluoropolymer. The oligomer or polymer can be impregnated in the fluoropolymer, mixed with the fluoropolymer, or tightly mixed with the fluoropolymer. In this case, the functional group can be derived from compounds selected from: acrylic acid, methacrylic acid, methyl methacrylate, ethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, hydroxyethylhexyl methacrylate, and acryloyloxypropyl succinate. For example, the functional group can be an oligomer or polymer comprising repeating units derived from monomers selected from: acrylic acid, methacrylic acid, methyl methacrylate, ethyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, hydroxyethylhexyl methacrylate, and acryloyloxypropyl succinate. According to one embodiment, the weight-average molecular weight of said oligomer or polymer is 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 particularly less than 20,000 g / mol. The average molecular weight was determined by GPC using a Waters 2695e apparatus coupled with a Wyatt NEON refractometer equipped with two PL Gel mixed C columns and a guard column (7.8 mm id × 30 cm, 5 μm) under the following conditions: temperature: 35 °C; flow rate: 1.0 mL / min; injection volume: 100 μL. Samples were prepared in THF at a concentration of 1 mg / mL. Twelve poly(methyl methacrylate) samples with molecular weights ranging from 535 to 2,210,000 g / mol were used as calibration standards. The oligomers or polymers were preferably added during the production of the fluoropolymer. The functional group content of the fluoropolymer was not less than 0.01 mol%, preferably not less than 0.1 mol%, and not more than 15 mol%, preferably not more than 10 mol%.

[0070] The fluoropolymer preferably has a high molecular weight. As used herein, high molecular weight means a fluoropolymer having a melt viscosity greater than 100 Pa·s, preferably greater than 500 Pa·s, and preferably greater than 1000 Pa·s, as measured according to ASTM D-3835 at 232 °C and 100 sec⁻¹.

[0071] The fluoropolymer used in this invention can be obtained by known polymerization methods such as emulsion or suspension polymerization. According to a preferred embodiment, the fluoropolymer is prepared by emulsion polymerization in the absence of a fluorinated surfactant. Therefore, the fluoropolymer may contain 10 ppm to 2% by weight of a non-fluorinated surfactant comprising a polyethylene glycol or polypropylene glycol moiety. Preferably, the non-fluorinated surfactant has an HLB value of 1 to 20, particularly 1 to 5 or 10 to 15. Specifically, the non-fluorinated surfactant comprises at least one polyethylene glycol segment and at least one 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, the non-fluorinated surfactant comprises at least one polyethylene glycol segment and at least one polypropylene glycol segment, and has an HLB value of 10 to 15 and a weight-average molecular weight of 500 g·mol⁻¹ to 2500 g·mol⁻¹.

[0072] According to a preferred embodiment, the fluoropolymer is prepared by suspension polymerization. Suspension polymerization is typically carried out in the presence of a dispersant. The dispersant may be polyvinyl alcohol (PVA) or a compound containing cellulose units (e.g., methylcellulose, hydroxypropyl methylcellulose, carboxymethylcellulose).

[0073] The fluoropolymer can be in the form of a latex, which typically has a solids content of 10% to 60%, preferably 10% to 50% by weight, and an average particle size of less than 1 micrometer, preferably less than 1000 nm, more preferably less than 800 nm, and even more preferably less than 600 nm by weight. The average particle size by weight is generally at least 20 nm, preferably at least 50 nm, and advantageously, in the range of 100 to 400 nm. The polymer particles can form agglomerates with an average weight particle size of 1 to 30 micrometers, and preferably 2 to 10 micrometers. During formulation and application to a substrate, agglomerates can be broken down into discrete particles.

[0074] The fluoropolymer may be in powder form. This is obtained from latex, which, for example, undergoes drying and optionally granulation steps.

[0075] According to some embodiments, the vinylidene fluoride contained in the fluoropolymer is bio-based. The term "bio-based" means "derived from biomass." This improves the eco-footprint of the polymer. Bio-based VDFs are characterized by a renewable carbon content, i.e., carbon from naturally occurring sources and carbon from biological materials or biomass, determined by the 14C content according to NF EN 16640, of at least 1% atoms. The term "renewable carbon" refers to carbon that is naturally occurring and derived from biological materials (or biomass), as described below. Depending on some embodiments, the biocarbon content of the VDF can be greater than 5%, preferably greater than 10%, preferably greater than 25%, preferably greater than or equal to 33%, preferably greater than 50%, preferably greater than or equal to 66%, preferably greater than 75%, preferably greater than 90%, preferably greater than 95%, preferably greater than 98%, preferably greater than 99%, advantageously equal to 100%.

[0076] Specifically, the fluoropolymer is poly(tetrafluoroethylene) (PTFE), which consists of repeating units derived from tetrafluoroethylene, or the fluoropolymer is a homopolymer of vinylidene fluoride, or the fluoropolymer is a copolymer of vinylidene fluoride with monomers M1b or M1c as defined herein.

[0077] polyamide thermoplastic polymer

[0078] Polyamide (homopolyamide or copolyamide, abbreviated as CoPA) refers to the polymerization or condensation product of the same monomer (in the case of homopolyamide) or several different monomers (in the case of CoPA), which are selected from:

[0079] -Amino acid or aminocarboxylic acid monomers, preferably α,ω-aminocarboxylic acid monomers;

[0080] - Substitutable lactam monomers having 3 to 18 carbon atoms on the main ring;

[0081] - Diamine-diacid monomers produced by the reaction between an aliphatic diamine having 4 to 18 carbon atoms and a carboxylic acid diacid having 4 to 18 carbon atoms; and

[0082] - Their mixtures, in the case of copolyamides formed by mixing amino acid monomers with lactam monomers, use monomers with different carbon numbers.

[0083] In this description of copolyamides, the term "monomer" refers to a "repeating unit." In practice, the specific embodiment where the repeating unit of the PA consists of a diacid and a diamine is considered. It is thought to be a combination of a diamine and a diacid, i.e., a diamine-diacid pair (equimolar amounts), which corresponds to the monomer. This is due to the fact that either the diacid or the diamine alone is merely a structural unit and is insufficient on its own to polymerize.

[0084] Amino acid monomers:

[0085] Examples of α-amino acids include those with 4 to 18 carbon atoms, such as aminohexanoic acid, amino-7-heptanoic acid, amino-11-undecanoic acid, n-heptyl-11-aminoundecanoic acid, and amino-12-dodecanoic acid.

[0086] Lactam monomers:

[0087] Examples of lactams include those having 3 to 18 carbon atoms on the host ring that can be substituted. Examples include ε,ε-dimethylpropiolactam, ε,ε-dimethylpropiolactam, amylolactam, caprolactam (also known as lactam 6), octyllactam (also known as lactam 8), heptanolactam, 2-pyrrolidone, and lauryllactam (also known as lactam 12).

[0088] "Diamine-Diacid" monomer:

[0089] Examples of dicarboxylic acids include acids having 4 to 18 carbon atoms. Examples include adipic acid, sebacic acid, azelaic acid, octanoic acid, isophthalic acid, succinic acid, 1,4-cyclohexyldicarboxylic acid, terephthalic acid, sodium or lithium salts of sulfoisophthalic acid, dimer fatty acids (which have a dimer content of at least 98% and are preferably hydrogenated), and dodecanoic acid HOOC-(CH2). 10 -COOH.

[0090] Examples of diamines include aliphatic diamines having 4 to 18 atoms, which may be aryl and / or saturated cyclic. Examples include hexamethylenediamine, piperazine, tetramethylenediamine, octamethylenediamine, decamethylenediamine, dodecamethylenediamine, 1,5-diaminohexane, 2,2,4-trimethyl-1,6-diaminohexane, diamine polyols, isophorone diamine (IPD), methylpentamethylenediamine (MPDM), bis(aminocyclohexyl)methane (BACM), bis(3-methyl-4-aminocyclohexyl)methane (BMACM), methylenediamine, bis-p-aminocyclohexylmethane, and trimethylhexamethylenediamine.

[0091] Examples of diamine-diacid monomers are monomers produced by the condensation of hexamethylenediamine with C6 to C36 diacids, particularly monomers 6.6, 6.10, 6.11, 6.12, 6.14, and 6.18. Examples include monomers produced by the condensation of decanediamine with C6 to C36 diacids, including monomers 10.10, 10.12, 10.14, and 10.18; or monomers produced by the condensation of decanediamine with terephthalic acid, i.e., monomer 10.T.

[0092] Examples of copolyamides formed from the aforementioned different types of monomers include those produced by the condensation of two or more α,ω-aminocarboxylic acids, two lactams, or one lactam and one α,ω-aminocarboxylic acid. Other examples include copolyamides produced by the condensation of at least one α,ω-aminocarboxylic acid (or lactam), at least one diamine, and at least one dicarboxylic acid. Copolyamides produced by the condensation of an aliphatic diamine with an aliphatic carboxylic acid and at least one monomer selected from those other than the aforementioned aliphatic diamine and aliphatic diacid may also be mentioned.

[0093] Examples of copolyamides include a copolymer of caprolactam and lauryl lactam (PA 6 / 12), a copolymer of caprolactam, hexamethylenediamine, and adipic acid (PA 6 / 6.6), a copolymer of caprolactam, lauryl lactam, hexamethylenediamine, and adipic acid (PA 6 / 12 / 6.6), and a copolymer of caprolactam, hexamethylenediamine, azelaic acid, 11-amino acid undecanoic acid, and lauryl lactam (PA 6 / 6.9 / 11 / 12). Copolymers of caprolactam, adipic acid, hexamethylenediamine, amino-11-undecanoic acid, and lauryl lactam (PA 6 / 6.6 / 11 / 12); copolymers of hexamethylenediamine, azelaic acid, and lauryl lactam (PA 6.9 / 12); copolymers of 2-pyrrolidone and caprolactam (PA 4 / 6); copolymers of 2-pyrrolidone and lauryl lactam (PA 4 / 12); copolymers of caprolactam and undecanoic acid amino acid 11 (PA 6 / 11); copolymers of lauryl lactam and caprolactam (PA 12 / 8); copolymers of 11-amino acid undecanoic acid and 2-pyrrolidone (PA 11 / 4); copolymers of caprolactam and caprolactam (PA 8 / 6); copolymers of caprolactam and 2-pyrrolidone (PA 8 / 4); copolymers of lauryl lactam and caprolactam (PA 8 / 6); copolymers of caprolactam and 2-pyrrolidone (PA 8 / 4); copolymers of lauryl lactam and caprolactam (PA 8 / 12 ... 12 / 8), a copolymer of lauryl lactam and amino-11-undecanoic acid (PA 12 / 11).

[0094] Particularly preferred materials are polyamide 11 and polyamide 12, as well as copolyamides using monomers 6, 12, 6.10, 6.12, 6.14, 6.18, 10.10, and 10.12, and more particularly, copolyamides using monomers 6, 12, 6.10, 6.12, 6.14, 6.18, 10.10, and 10.12.

[0095] Although the invention has been generally described in this application with reference to powders of copolyamides containing monomers 6, 12, 6.10, 6.12, 6.14, 6.18, 10.10 and 10.12, PA12 and PA11 (which have the additional advantage of being of renewable origin) according to preferred embodiments of the invention, the invention is obviously not limited to these powders. The invention includes any PA powder (homopolyamide or copolyamide) wherein the particles exhibit a particle size Dv50 of less than 300 μm, preferably less than 100 μm and more preferably less than 30 μm.

[0096] Polyamides or copolyamides can be obtained by melt condensation of a single type of monomer or two different types of monomers as described above.

[0097] Some suitable polyamides or copolyamides are available from ARKEMA under the trademarks RILSAN® and Platamid®, or from EVONIK under the trademarks VESTAMID® and VESTAMELT®, or from EMS under the trademarks GRILAMID® and GRILTEX®.

[0098] Suitable polyamides (e.g., PA 12) or copolyamides according to the invention can also be obtained by anionic polymerization of lactams in a solvent or solution. Some suitable ones are commercially available from Arkema under the trademark ORGASOL®.

[0099] In a preferred embodiment, the melt temperature of the polyamide thermoplastic polymer is below 230°C, advantageously below 220°C, preferably below 210°C, more preferably below 200°C, most preferably below 190°C, particularly below 180°C, even more particularly below 170°C, and most particularly below 160°C. The melt temperature can be measured according to ISO 11357-3 Plastics - Differential scanning calorimetry (DSC) Part 3.

[0100] In a preferred embodiment, the polyamide thermoplastic polymer is amorphous or semi-crystalline. Preferably, the polyamide thermoplastic polymer is semi-crystalline.

[0101] In a preferred embodiment, the polyamide thermoplastic polymer has a particle size distribution Dv50 of less than 30 μm, advantageously less than 28 μm, preferably less than 26 μm, more preferably less than 24 μm, most preferably less than 22 μm, particularly less than 20 μm, more particularly less than 18 μm, and most particularly less than 16 μm. In a preferred embodiment, the polyamide thermoplastic polymer has a particle size distribution Dv50 of less than 14 μm, advantageously less than 12 μm, and preferably less than 10 μm. The particle size Dv50 claimed in this application allows for improved electrode efficiency. The particle size distribution Dv50 of the polyamide thermoplastic polymer can be selected based on the particle size distribution Dv50 of the at least one active material. For example, the particle size distribution Dv50 of the polyamide thermoplastic polymer is less than 90% of the particle size distribution Dv50 of the at least one active material; preferably, the particle size distribution Dv50 of the polyamide thermoplastic polymer is less than 85% of the particle size distribution Dv50 of the at least one active material.

[0102] In a preferred embodiment, the polyamide thermoplastic polymer has a particle size distribution Dv90 of less than 500 μm, advantageously less than 450 μm, preferably less than 400 μm, more preferably less than 350 μm, most preferably less than 300 μm, particularly less than 250 μm, more particularly less than 200 μm, and most particularly less than 150 μm. In a preferred embodiment, the polyamide thermoplastic polymer has a particle size distribution Dv90 of less than 100 μm, advantageously less than 50 μm, and preferably less than 20 μm. The particle size Dv90 claimed in this application allows for improved electrode efficiency.

[0103] Intrinsic viscosity was measured using an Ubbelohde tube. The measurement was performed on a 75 mg sample containing 0.5% (w / w) m-cresol at 20°C. Intrinsic viscosity is expressed as (g / 100g). -1 And calculate according to the following formula:

[0104] Intrinsic viscosity = ln(t) s / t0)x 1 / C, where C=m / px 100,

[0105] Where t s t0 is the flow time of the solution, t0 is the solvent flow time, m is the mass of the sample, and p is the mass of the solvent. This measurement corresponds to the ISO 307 standard, except that the measurement temperature is 20°C instead of 25°C.

[0106] The intrinsic viscosity of the polyamide thermoplastic polymer is less than or equal to 1.2, advantageously less than or equal to 1.1, preferably less than or equal to 1.0, and more preferably less than or equal to 0.9 (g / 100g). -1 .

[0107] Polyether block amide

[0108] Polyether block amide (PEBA) is a copolymer having amide units (Ba1) and polyether units (Ba2), wherein the amide units (Ba1) correspond to aliphatic repeating units selected from units obtained from at least one amino acid or from at least one lactam, or units XY obtained by the following condensation polymerization:

[0109] - At least one diamine, preferably selected from straight-chain or branched aliphatic diamines or mixtures thereof, and

[0110] - At least one carboxylic acid diacid, preferably selected from:

[0111] Straight-chain or branched aliphatic diacids or mixtures thereof,

[0112] The diamine and the diacid contain 4 to 36 carbon atoms, advantageously 6 to 18 carbon atoms;

[0113] The polyether unit (Ba2) is particularly derived from at least one polyalkylene ether polyol, especially polyalkylene ether diol.

[0114] PEBA is particularly derived from the cocondensation of a polyamide sequence with reactive ends and a polyether sequence with reactive ends, for example, especially:

[0115] 1) Polyamide sequences with diamine chain ends and polyoxyalkylene sequences with dicarboxylic acid chain ends.

[0116] 2) A polyamide sequence with a dicarboxylic acid chain terminus and a polyoxyalkylene sequence with a diamine chain terminus, which are obtained by cyanoethylation and hydrogenation of an α-ω dihydroxylated aliphatic polyoxyalkylene sequence called polyalkylene ether diol (polyether diol).

[0117] 3) A polyamide sequence having a dicarboxylic acid chain terminus and a polyether diol, in this particular case, yields a polyether ester amide. The copolymers of the present invention are advantageously of this type.

[0118] Polyamide sequences with dicarboxylic acid chain ends, for example, are derived from the condensation of polyamide precursors in the presence of chain-limiting carboxylic acid diacids.

[0119] Polyamide sequences with diamine chain ends, for example, are derived from the condensation of polyamide precursors in the presence of chain-limiting diamines.

[0120] Polyamide and polyether block polymers can also contain randomly distributed units. These polymers can be prepared by the simultaneous reaction of polyether and polyamide block precursors.

[0121] For example, polyether glycols, polyamide precursors, and chain-limiting agents can be reacted with diacids. The result is polymers with polyether blocks and polyamide blocks that are essentially highly variable in length, and a variety of reagents with random reactions that are randomly (statistically) distributed along the polymer chain.

[0122] Alternatively, polyether diamine, polyamide precursors, and chain-limiting agents can be reacted with diacids. The result is polymers with polyether blocks and polyamide blocks that are essentially highly variable in length, and a variety of reagents with random reactions that are randomly (statistically) distributed along the polymer chain.

[0123] Amide unit (Ba1):

[0124] The amide unit (Ba1) corresponds to the aliphatic repeating unit as defined above. Advantageously, the amide unit (Ba1) is selected from polyamide 11, polyamide 12, polyamide 6.10, polyamide 6.12, polyamide 10.10, polyamide 10.12, and especially polyamide 11. More advantageously, the amide unit (Ba1) is selected from polyamide 11 and polyamide 12, especially polyamide 11.

[0125] Polyether unit (Ba2):

[0126] The polyether units are particularly derived from at least one polyalkylene ether polyol, and in particular, they are derived from at least one polyalkylene ether polyol; in other words, the polyether units consist of at least one polyalkylene ether polyol. In this embodiment, the statement "at least one polyalkylene ether polyol" means that the polyether unit consists only of alcohol chain ends, and therefore cannot be a polyether diamine triblock compound. Therefore, the compositions of the present invention do not contain polyether diamine triblocks. Advantageously, the polyether unit (Ba2) is selected from polyethylene glycol (PEG), polypropylene glycol (PPG), polytrimethylene glycol (PO3G), polytetramethylene glycol (PTMG), and mixtures or copolymers thereof, especially PTMG. The number average molecular weight (Mn) of the polyether block is advantageously 200-4000 g / mol, preferably 250-2500 g / mol, and especially 300-1100 g / mol.

[0127] PEBA can be prepared by the following methods, wherein:

[0128] - In the first step, polyamide blocks (Ba1) are prepared by the following polycondensation.

[0129] -lactam, or

[0130] - amino acids, or

[0131] Diamines and carboxylic acids; and, if desired, comonomers selected from lactams and α-ω-aminocarboxylic acids;

[0132] In the presence of a chain-limiting agent selected from carboxylic acids; then

[0133] - In the second step, the obtained polyamide block (Ba1) is reacted with the polyether block (Ba2) in the presence of a catalyst.

[0134] General methods for the two-step preparation of the copolymers of the present invention are known and described, for example, in French Patent FR 2846 332 and European Patent EP 1 482 011.

[0135] The reaction that forms the block (Ba1) is typically carried out at 180–300 °C, preferably 200–290 °C; the pressure inside the reactor is 5 to 30 bar and is maintained for about 2 to 3 hours. The pressure is then slowly reduced by bringing the reactor to atmospheric pressure, and the excess water is then distilled off, for example, over one or two hours.

[0136] Once the polyamide with carboxylic acid end groups is prepared, a polyether and a catalyst are added. The polyether can be added in one or more stages, as can the catalyst. In an advantageous embodiment, the polyether is added first, and the reaction between the OH end groups of the polyether and the COOH end groups of the polyamide begins with the formation of ester bonds and the removal of water. As much water as possible is removed from the reaction medium by distillation, and then the catalyst is introduced to complete the bonding of the polyamide and polyether blocks. This second step is carried out under stirring, preferably under a vacuum of at least 15 mm Hg (2000 Pa), at a temperature that keeps the obtained reagents and copolymers in a molten state. For example, this temperature can be between 100 and 400 °C, most commonly between 200 and 300 °C. The reaction is monitored by measuring the torque applied to the stirrer by the molten polymer or by measuring the electrical power consumed by the stirrer. The termination of the reaction is determined by the value of the target torque or power.

[0137] One or more molecules used as antioxidants, such as Irganox®1010 or Irganox®245, may also be added during the synthesis process at what is considered the most appropriate time.

[0138] Alternatively, a PEBA preparation method could be considered, in which all monomers are added in a single step at the outset to perform the following polycondensation:

[0139] -lactam, or

[0140] - Amino acid content, or

[0141] -Diamine and carboxylic acid; and optionally, other polyamide comonomers;

[0142] -In the presence of a chain-limiting agent selected from carboxylic acids;

[0143] - In the presence of block (Ba2) (polyether);

[0144] - In the presence of a catalyst for the reaction between the soft block (Ba2) and the block (Ba1).

[0145] Advantageously, the carboxylic acid is used as a chain limiting agent, which is introduced in stoichiometric excess relative to the diamine.

[0146] Advantageously, derivatives of metals selected from titanium, zirconium, and hafnium, or strong acids such as phosphoric acid, hypophosphoric acid, or boric acid are used as catalysts.

[0147] Polycondensation can be carried out at temperatures between 240 and 280 °C.

[0148] Generally, known copolymers with ether and amide units consist of linear and semi-crystalline aliphatic polyamide sequences (e.g., Arkema's "Pebax").

[0149] In one embodiment, the copolyamide having amide units (Ba1) and polyether units (Ba2) has a density greater than or equal to 1, particularly greater than or equal to 1.01, especially greater than or equal to 1.02, as determined according to ISO 1183-3:1999.

[0150] Advantageously, as measured at 23 °C according to standard ISO 178:2010, the modulus of PEBA(A) is less than 250 MPa, particularly less than 200 MPa, particularly less than 150 MPa, and even more particularly less than 100 MPa.

[0151] In a preferred embodiment, the polyether block amide has a particle size distribution Dv50 of less than 100 μm, advantageously less than 95 μm, preferably less than 90 μm, more preferably less than 85 μm, most preferably less than 80 μm, particularly less than 75 μm, more particularly less than 70 μm, and most particularly less than 65 μm. In a specific embodiment, the particle size distribution Dv50 of the polyether block amide is less than 60 µm, advantageously less than 55 µm, preferably less than 50 µm, more preferably less than 45 µm, most preferably less than 40 µm, particularly less than 35 µm, more particularly less than 30 µm, and most particularly less than 25 µm. The particle size Dv50 claimed in this application allows for improved electrode efficiency. The particle size distribution Dv50 of the polyether block amide can be selected based on the particle size distribution Dv50 of the at least one active material. For example, the particle size distribution Dv50 of the polyether block amide can be less than 90% of the particle size distribution Dv50 of the at least one active material.

[0152] In a preferred embodiment, the polyether block amide has a particle size distribution Dv90 of less than 500 μm, advantageously less than 450 μm, preferably less than 400 μm, more preferably less than 350 μm, most preferably less than 300 μm, particularly less than 250 μm, more particularly less than 200 μm, and most particularly less than 150 μm. In a particular embodiment, the polyether block amide has a particle size distribution Dv90 of less than 100 μm, advantageously less than 90 μm, preferably less than 80 μm, more preferably less than 70 μm, most preferably less than 60 μm, particularly less than 50 μm, more particularly less than 40 μm, and most particularly less than 30 μm. The particle size Dv90 claimed in this application allows for improved electrode efficiency.

[0153] Uses of the dry composition

[0154] Dry compositions can be used to prepare electrodes. The latter can be prepared from a thin film made of the dry composition subsequently placed on a current collector, or the dry composition can be coated (by direct calendering or electrospraying and calendering) onto the current collector without the need to prepare a separate thin film.

[0155] According to one implementation, after the powder mixing step, the electrode is manufactured by solvent-free spraying, by depositing the formulation onto a metal substrate, by pneumatic spraying, by electrostatic spraying, by immersion in a fluidized powder bed, by spraying, by electrostatic screen printing, by deposition with a rotating brush, by deposition with a metered feed rotating roller, or by calendering.

[0156] According to one embodiment, after the powder mixing step, the electrode is manufactured by a two-step solvent-free method. The first step involves manufacturing a self-supporting film from the premixed formulation using thermomechanical methods such as extrusion, calendering, or hot pressing. In the second step, the self-supporting film is laminated onto a metal substrate using a combination of temperature and pressure methods such as calendering or hot pressing.

[0157] The dry composition of the present invention can be used to prepare membranes. Therefore, the present invention provides a membrane comprising, preferably composed of, the dry composition of the present invention. In a preferred embodiment, for the anode composition, the membrane density is less than 1.65 g / cc, advantageously less than 1.64 g / cc, preferably less than 1.63 g / cc, more preferably less than 1.62 g / cc, most preferably less than 1.61 g / cc, particularly less than 1.60 g / cc, even more particularly less than 1.59 g / cc, and most particularly less than 1.58 g / cc. In a preferred embodiment, the membrane density is greater than 1.45 g / cc, advantageously greater than 1.46 g / cc, preferably greater than 1.47 g / cc, and more preferably greater than 1.48 g / cc. The anode composition refers to the dry composition wherein the active material is the anode active material as detailed above.

[0158] In another embodiment, for the cathode composition, the membrane density is greater than 1.65 g / cc, advantageously greater than 1.66 g / cc, preferably greater than 1.67 g / cc, more preferably greater than 1.68 g / cc, most preferably greater than 1.69 g / cc, and particularly greater than 1.70 g / cc. The cathode composition refers to a dry composition in which the active material is the cathode active material as detailed above.

[0159] The density is measured by cutting the membrane into 2 cm × 2 cm squares, weighing them using a balance, and then dividing the weight by the membrane's volume. The membrane thickness can be measured using a spectrometer according to any method known in the art. It has been observed that improved high-rate capacity can be obtained by using membranes with the aforementioned density.

[0160] In a preferred embodiment, the thickness of the membrane is from 5 μm to 500 μm.

[0161] Therefore, the membrane can be used to manufacture dry-coated electrodes. Accordingly, the present invention provides a method for preparing a dry-coated electrode according to the invention, the method comprising the steps of: dry-mixing at least one active material, at least one binder, and optionally at least one conductive agent to provide an electrode formulation; processing the electrode formulation to form a self-supporting membrane; and laminating the self-supporting membrane onto a substrate to form a laminated membrane coated on the substrate, preferably on a current collector. This method is particularly suitable when the at least one binder comprises a fibrillable fluoropolymer and a polyamide thermoplastic polymer. The step of processing the electrode formulation to form a membrane can be carried out over a wide temperature range (15 °C to 300 °C). For convenience, the step of processing the electrode formulation to form a membrane can be carried out at a low temperature of 15 °C to 50 °C.

[0162] Dry compositions can also be used to prepare dry-coated electrodes by solvent-free methods. Therefore, the present invention provides a dry-coated electrode comprising the dry composition of the present invention coated onto a substrate, preferably a current collector, by a solvent-free method. A method for preparing a dry-coated electrode according to the present invention comprises the following steps: dry-mixing at least one active material, at least one binder, and optionally at least one conductive agent to provide an electrode formulation; depositing the electrode formulation onto a substrate by a solvent-free method to obtain a lithium-ion battery electrode; and consolidating the electrode by thermomechanical treatment at a temperature of 15 °C to 300 °C. Thermomechanical treatment refers to applying temperature under mechanical pressure. The pressure applied during thermomechanical treatment is typically less than 1 kN / mm, preferably less than 0.75 kN / mm, more preferably less than 0.5 kN / mm. This thermomechanical treatment can be carried out, for example, by a calender with heated rollers or a plate-to-plate press that can also be heated.

[0163] The preferred thickness of the electrode is 0.1 μm to 1000 μm, more preferably 0.1 μm to 300 μm.

[0164] The current collector of the electrode can also be coated with a primer layer to improve the adhesion of the dry composition thereon. The primer layer may contain a polymer selected from fluoropolymers and (meth)acrylic acid-based polymers or mixtures thereof. The primer layer can be applied to the current collector, followed by the application of the dry composition onto the primer layer. The primer layer may also contain a conductive material selected from: carbon black, such as acetylene black, Ketjen black; carbon fibers, such as carbon nanotubes, carbon nanofibers, vapor-grown carbon fibers; metal powders, such as SUS powder and aluminum powder. Preferably, the primer layer contains 10% to 60% of the conductive material. The primer layer may also contain an inorganic filler having a melting point of 200 °C or higher and high electrical insulation properties, and being electrochemically stable within the application range of lithium-ion secondary batteries. The inorganic filler is selected from oxide ceramics, such as alumina, silicon dioxide, titanium dioxide, zirconium oxide, magnesium oxide, cerium dioxide, yttrium oxide, zinc oxide, and iron oxide; nitride ceramics, such as silicon nitride, titanium nitride, and boron nitride; ceramics, such as silicon carbide, calcium carbonate, magnesium sulfate, aluminum sulfate, aluminum hydroxide, aluminum hydroxide oxide, potassium titanate, talc, kaolinite, dickite, perlite, halloysite, pyrophyllite, montmorillonite, sericite, mica, magnesia chlorite, bentonite, asbestos, zeolite, calcium silicate, magnesium silicate, diatomaceous earth, and silica sand; and glass fiber. Preferably, the primer layer contains 10% to 80% of the conductive material. The (meth)acrylic-based polymer can be polymer P1 of formula (Ia) as defined in this application. The fluoropolymer may comprise repeating units derived from monomers selected from: vinyl fluoride; vinylidene fluoride (VDF); 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-m-dioxane)... Cyclopentene); perfluoro(2,2-dimethyl-1,3-m-dioxacyclopentene) (PDD); monomers having the formula CF2=CFOCF2CF(CF3)OCF2CF2X, where X is SO2F, CO2H, CH2OH, CH2OCN, or CH2OPO3H; monomers having the formula CF2=CFOCF2CF2SO2F; monomers having the formula F(CF2)nCH2OCF=CF2, where n is 1, 2, 3, 4, or 5; monomers having the formula R 1 The monomer of CH2OCF=CF2, where R 1 It is hydrogen or F(CF2)m, and m is 1, 2, 3 or 4; having the formula R 2 The monomer of OCF=CH2, where R 2It is F(CF2)p and p is 1, 2, 3 or 4; trifluoropropylene, tetrafluoropropylene, hexafluoroisobutylene, perfluorobutene, pentafluoropropylene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropylene and 2-trifluoromethyl-3,3,3-trifluoro-1-propylene or mixtures thereof.

[0165] In another aspect, the present invention provides a lithium-ion battery. The lithium-ion battery includes a positive electrode, a negative electrode, and a separator, wherein at least one of these electrodes is a dry-coated electrode according to the present invention. The lithium-ion battery may further include an electrolyte. The electrolyte may be selected from LiCF3SO3, LiPF6, LiClO4, LiBF4, LiB(C2O4)2, LiN(SO2F)2, LiN(SO2CF3)2, LiN(SO2C2F3)2, LiN(SO2C2F5)2, LiN(SO2F)(SO2CF3), LiN(SO2F)(SO2C2F5), LiN(SO2CF3)(SO2C2F5), LiAsF6, LiBF2C2O4, LiNO3, LiPF3(CF2CF3)3, LiBETI, LiTDI, and mixtures thereof.

[0166] Example

[0167] Preparation of coated Cu foil:

[0168] 1.6 g of Kynar HSV1810 (PVDF, Arkema) was dissolved in 18.4 g of N-methylpyrrolidone to obtain an 8% by weight solution. 10 g of the solution was transferred to a 125 ml capped plastic container. 0.8 g of Super P-Li (carbon black powder, Imerys) was added to the solution. Five 5 mm φ zirconium oxide beads were then added, and the mixture was stirred in ARE-310 (Thinky) at 2000 rpm for 30 seconds. 3 g of N-methylpyrrolidone was added, and the mixture was stirred again in ARE-310 at 2000 rpm for 30 seconds. This process was repeated until a total of 12 g of N-methylpyrrolidone was added and mixed. The resulting Super P-Li slurry was cast onto a Cu foil to a wet thickness of 4 mils, and then dried at 120 °C for 10 minutes to obtain a coated Cu foil.

[0169] Example 1

[0170] 158-C (graphite, BTR, Dv50 = 16 μm), polytetrafluoroethylene (Dv50 = 470 μm), and copolyamide 6 / 12 powder (melting temperature 142 °C and Dv50 = 10 μm) were mixed in a mortar at a weight ratio of 95 / 2.5 / 2.5. The mixed powder was pressed in a roller press at 160 °C and 0 kN to obtain a film. The film was laminated onto a coated Cu foil by a roller press at 160 °C and 2 kN. The density of the laminated film was 1.52 g / cc. The prepared anode structure was used to prepare a battery with a PE separator and Li metal as the cathode. The PE separator was sandwiched between the anode structure and the Li metal in a glove box to obtain the battery structure. The battery structure was placed in a container, electrolyte was injected, and it was sealed to obtain a coin cell. The prepared coin cell was discharged at C / 10 to 0.05 V and then charged at C / 10 to 2 V. Coulombic efficiency is obtained by dividing the charging capacity by the discharging capacity.

[0171] Example 2

[0172] The same method as in Example 1 was used, except that polyamide 12 powder (melting temperature 177 °C, Dv50 = 10 μm) was used instead of copolyamide. The density of the laminated film was 1.54 g / cc.

[0173] Example 3

[0174] The same method as in Example 1 was used, except that a polyether-amide block copolymer (melting temperature 135 °C, D50 = 60-70 μm) was used instead of a copolyamide, and the formulation was changed to graphite / PTFE / polyether-amide block copolymer = 98 / 1 / 1 by weight. A uniform self-supporting film was formed.

[0175] Comparative Example

[0176] The same method as in Example 1 was used, except that polyvinylidene fluoride was used instead of copolyamide. The density of the laminated film was 1.70 g / cc.

[0177] The initial coulomb efficiencies of each embodiment are listed in Table 1.

[0178] [Table 1]

[0179]

[0180] It was observed that the initial coulombic efficiency increased when the binder used in the electrode contained both fluoropolymers and polyamide thermoplastic polymers, rather than just fluoropolymers. This increase in initial coulombic efficiency was accompanied by a reduction in power loss during charge / discharge cycles in the lithium-ion battery. The same effect was observed when a non-fibrillable fluoropolymer was used instead of a fibrillable fluoropolymer.

Claims

1. A dry composition comprising at least one active material, at least one binder, and optionally at least one conductive agent, characterized in that... The at least one adhesive comprises a fluoropolymer and a polyamide thermoplastic polymer or a polyether block amide or a mixture thereof.

2. The dry composition according to any one of the preceding claims, wherein the particle size distribution Dv50 of the polyamide thermoplastic polymer is less than 30 μm.

3. The dry composition according to any one of the preceding claims, wherein the fluoropolymer is a fibrillable fluoropolymer, preferably comprising repeating units derived from monomer M1a, wherein monomer M1a is tetrafluoroethylene.

4. The dry composition according to the preceding claim, wherein the particle size distribution Dv50 of the fibrillable fluoropolymer is less than 1000 μm.

5. The dry composition according to claim 1 or 2, wherein the fluoropolymer is a non-fibrillable polymer; preferably comprising repeating units derived from a monomer M1a selected from: vinylidene fluoride, trifluoroethylene, 1,2-difluoroethylene, perfluoro(alkyl vinyl) ether, perfluoro(1,3-m-dioxacyclopentene), perfluoro(2,2-dimethyl-1,3-m-dioxacyclopentene), monomers of the formula CF2=CFOCF2CF(CF3)OCF2CF2X, wherein X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H, monomers of the formula CF2=CFOCF2CF2SO2F, or F(CF2). n The monomer of CH2OCF=CF2, where n is 1, 2, 3, 4 or 5, Equation R 1 The monomer of CH2OCF=CF2, where R 1 It is hydrogen or F (CF2). m And m is 1, 2, 3 or 4, Equation R 2 The monomer of OCF=CH2, where R 2 Let F(CF2) be the value. p And p is 1, 2, 3 or 4, perfluorobutylethylene, 3,3,3-trifluoropropylene, tetrafluoropropylene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropylene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropylene, ethylene and 2-trifluoromethyl-3,3,3-trifluoro-1-propylene or mixtures thereof; in particular, the fluoropolymer comprises repeating units derived from vinylidene fluoride.

6. The dry composition according to the preceding claim, wherein the particle size distribution Dv50 of the non-fibrillable fluoropolymer is less than 100 μm.

7. The dry composition according to any one of the preceding claims, wherein the polyamide thermoplastic polymer is selected from PA6, PA11, PA12, PA6.10, PA6.12, PA6.14, PA6.18, PA10.10, PA10.12, copolyamides and mixtures thereof.

8. The dry composition according to any one of claims 1, 3 to 6, wherein the polyether block amide is a copolymer having amide units (Ba1) and polyether units (Ba2), wherein the amide units (Ba1) correspond to aliphatic repeating units selected from units obtained from at least one amino acid or from at least one lactam, or units X·Y obtained by the following polycondensation: - At least one diamine, preferably selected from straight-chain or branched aliphatic diamines or mixtures thereof, and - At least one carboxylic acid diacid, preferably selected from: straight-chain or branched aliphatic diacids, or mixtures thereof. The diamine and the diacid contain 4 to 36 carbon atoms, advantageously 6 to 18 carbon atoms; the polyether unit (Ba2) is particularly derived from at least one polyalkylene ether polyol, especially polyalkylene ether diol.

9. The dry composition according to any one of the preceding claims, wherein the at least one active material is selected from: LiCoO2, Li(Ni,Co,Al)O2, Li (1+x) Ni a Mn b Co c (x represents a real number 0 or greater, a = 0.9, 0.8, 0.6, 0.5 or 1 / 3, b = 0.05, 0.1, 0.2, 0.3 or 1 / 3, c = 0.05, 0.1, 0.2 or 1 / 3), LiNiO2, LiMn2O4, LiCoMnO4, Li3NiMn3O3, Li3Fe2(PO4)3, Li3V2(PO4)3, possessing properties derived from Li (1+x) Mn (2-x-y) M y O4 represents LiMn spinel with different elemental substitutions, where M represents at least one metal selected from Al, Mg, Co, Fe, Ni, and Zn, and x and y independently represent real numbers between 0 and 2, lithium titanate Li x TiO y , where x and y independently represent real numbers between 0 and 2, and have a lithium metal phosphate composition represented by LiMPO4, and M represents Fe, Mn, Co or Ni.

10. The dry composition according to any one of claims 1 to 8, wherein the at least one active material is selected from lithium metal, lithium alloys, metal oxides, carbon materials such as graphite or hard carbon, silicon, silicon alloys, and Li4Ti5O. 12 .

11. The dry composition according to any one of the preceding claims, having the following mass composition: a. 50% to 99.9%, preferably 50% to 99%, of the at least one active material, b. 0% to 25%, preferably 0.5% to 25% of the at least one conductive agent, c. 0.1% to 25%, preferably 0.5% to 25% of the at least one adhesive, d. 0% to 5% of at least one additive selected from plasticizers, ionic liquids, dispersants for conductive additives, and flow aids; The sum of all these percentages is 100%.

12. A membrane comprising the dry composition of any one of the preceding claims, preferably consisting of the dry composition of any one of the preceding claims.

13. The membrane according to the preceding claim, wherein the active material contained in the dry composition is selected from lithium metal, lithium alloys, metal oxides, carbon materials such as graphite or hard carbon, silicon, silicon alloys, and Li4Ti5O. 12 At that time, the membrane had a density of less than 1.65 g / cc.

14. The membrane according to claim 12, wherein the density of the membrane is greater than 1.65 g / cc when the active material contained in the dry composition is selected from the following: LiCoO2, Li(Ni,Co,Al)O2, Li (1+x) Ni a Mn b Co c (x represents a real number 0 or greater, a = 0.9, 0.8, 0.6, 0.5, or 1 / 3, b = 0.05, 0.1, 0.2, 0.3, or 1 / 3, c = 0.05, 0.1, 0.2, or 1 / 3), LiNiO2, LiMn2O4, LiCoMnO4, Li3NiMn3O3, Li3Fe2(PO4)3, Li3V2(PO4)3, possessing properties derived from Li (1+x) Mn (2-x-y) M y O4 represents LiMn spinel with different elemental substitutions, where M represents at least one metal selected from Al, Mg, Co, Fe, Ni, and Zn, and x and y independently represent real numbers between 0 and 2, lithium titanate Li x TiO y , where x and y independently represent real numbers between 0 and 2, and lithium metal phosphates with a composition represented by LiMPO4, and M represents Fe, Mn, Co or Ni.

15. A dry-coated electrode comprising a dry composition according to any one of claims 1 to 11, coated onto a substrate by a solvent-free method.

16. A lithium-ion battery comprising a positive electrode, a negative electrode, and a separator, wherein at least one of the electrodes is a dry-coated electrode according to the preceding claim.

17. A method for preparing a dry-coated electrode according to claim 15, the method comprising the following steps: At least one active material, at least one adhesive, and optionally at least one conductive agent are dry-mixed to provide an electrode formulation; the electrode formulation is processed to form a self-supporting film, and the self-supporting film is laminated onto a substrate to form a laminated film coated on the substrate.

18. A method for preparing a dry-coated electrode according to claim 15, the method comprising the following steps: At least one active material, at least one binder, and optionally at least one conductive agent are dry-mixed to provide an electrode formulation; The electrode formulation is deposited on a substrate using a solvent-free method to obtain a lithium-ion battery electrode; the electrode is then solidified by thermomechanical treatment at a temperature of 15 °C to 300 °C.

Images