Compositions comprising fluorinated polymers and acrylic copolymers and their use as electrode binders

Abstract

The present invention relates to a composition comprising a fluoropolymer P1 comprising monomer units derived from a fluoromonomer M1a and a copolymer P2 comprising monomer units derived from a monomer M2a comprising monomer units derived from a fluoromonomer M1a and monomer units derived from a monomer M2b of formula (II). The composition is used as electrode binder. 1 R 2 C=C(R 3 )C(O)R or (Ib) R 1 R 2 C=C(R 3 )R’’ and monomer units derived from a monomer M2b of formula (II). The composition is used as electrode binder.

Description

Technical Field

[0001] This invention generally relates to the field of storing electrical energy in lithium-ion type rechargeable batteries. More specifically, this invention relates to a composition for electrode preparation. Background Technology

[0002] Lithium-ion batteries are increasingly used due to their higher voltage and higher energy density compared to conventional batteries (such as Ni-MH batteries). The basic lithium-ion battery, or lithium battery, consists of an anode (for discharging) and a cathode (also for discharging), which are typically composed 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 batteries, or accumulators, are more advantageous than primary batteries (which are non-rechargeable) because the chemical reactions occurring at the positive and negative electrodes are reversible. The electrodes of a storage cell can be regenerated several times by applying charge. Many advanced electrode systems have been developed for storing charge. Meanwhile, significant efforts have been made to develop 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 coated in the form of a film. The composite material consists of: a material known as the active ingredient (because it has electrochemical activity with respect to lithium), a polymer acting as a binder, plus one or more conductive additives (typically carbon black or acetylene black), and optionally a surfactant.

[0005] Binders are counted in the category of inactive components because they do not directly contribute to battery capacity. However, their crucial role in electrode processing 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 strong cohesion), and flexibility. The primary purpose of using binders is to form a stable network (cohesion) of the solid components of the electrode, namely 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 adhesive properties, and strong adhesion to electrode materials and current collectors. In the wet suspension process used to prepare electrodes, the active material and binder are dispersed in a liquid solution. The liquid solution is typically based on an organic solvent or water. The dispersion is poured onto a current collector and then dried in a high-temperature oven to manufacture the electrode. Unfortunately, the excellent properties provided by fluoropolymers such as PVDF may also limit the applications in which they can be used. For example, it is difficult to adhere fluoropolymers to other materials. Therefore, organic solvents and other organic additives are often used in coating formulations to ensure good adhesion between PVDF-based polymers, porous membranes or electrodes, and optionally added powdered particles. Alternatively, fluoropolymer binders may contain functional groups to promote the adhesive behavior of the polymer. For example, US 2020 / 0407543 describes a polymer binder composition comprising two or more different phases, wherein the phases comprise a highly crystalline fluoropolymer phase and an adhesive fluoropolymer phase containing functional groups.

[0007] Adhesive compositions comprising mixtures of vinylidene fluoride polymers and acrylic polymers are also described in the art. For example, US 2013 / 252077 describes an electrode for a lithium-ion battery that operates with a non-aqueous electrolyte. This electrode comprises an active material and an adhesive comprising a vinylidene fluoride polymer and an acrylic polymer. EP 2 953 193 describes an adhesive for a lithium-ion battery comprising a fluoropolymer and an acrylic polymer containing nitrile groups. EP 3796 430 describes an electrode mixture comprising an adhesive composition containing a vinylidene fluoride copolymer and an acrylic polymer with a low average molecular weight.

[0008] However, the adhesion of the binder composition is not always satisfactory and can still be improved. This is because the electrode material can become segregated from the current collector, leading to poor electrochemical performance and reduced cycle life. Therefore, it is important to find a cost-effective and scalable method to improve the adhesion of electrode materials in batteries. Furthermore, increasing the mass power density of electric vehicle batteries remains a major challenge for the large-scale adoption of this technology; to this end, improving the retention rate of high charge cycle capacity of electrodes with high Ni content will enable these goals to be achieved in terms of cost and fast charging cycles.

[0009] Therefore, there is still a need to develop new binder and electrode compositions for lithium-ion batteries to improve the adhesion of electrode materials and high charge cycle capacity retention. Summary of the Invention

[0010] According to a first aspect, the present invention relates to a composition comprising a fluoropolymer P1 and a copolymer P2, wherein the fluoropolymer P1 comprises monomer units generated from a fluorinated monomer M1a, and the copolymer P2 comprises monomer units generated from at least one of the formula (Ia)R 1 R 2 C=C(R 3 )C(O)R or (Ib)R 1 R 2 C=C(R 3 Monomer units generated from monomer M2a of formula (II) and monomer units generated from monomer M2b of formula (II):

[0011]

[0012] in:

[0013] Substituent R 1 R 2 and R 3 Each of the elements is independently selected from H, C1-C5 alkyl groups, and NH2; R” is selected from C6-C 12 Aryl and CN; R is selected from -NHC(CH3)2CH2C(O)CH3 and -OR', where R' is selected from H and C1-C 18 Alkyl, the C1-C 18 The alkyl group is optionally substituted with one or more -OH, -CO2H, -SO3H, -PO3H, -OC(O)R”' or -C(O)OR”' groups, or a five- or ten-membered heterocycle, wherein the five- or ten-membered heterocycle contains at least one nitrogen atom in its ring chain; R”' is selected from C1-C6 alkyl groups and C6-C6 alkyl groups optionally substituted with one or more -OH, -CO2H, -SO3H or -PO3H groups. 12 Aryl;

[0014] Substituent R 4 R 5 R 6 and R 9 They are independently selected from H and C1-C5 alkyl groups;

[0015] R 7 and R 8 They are selected independently of each other and for each unit n from H and C1-C5 alkyl groups;

[0016] Substituent X is selected from C1-C 18 Alkyl and C4-C 18 Cycloalkyl; n is an integer from 1 to 10, preferably from 1 to 5; in particular, n is 1.

[0017] The compositions of the present invention enable improved adhesion properties of the electrode composition to the current collector. Furthermore, the compositions of the present invention enable very impressive capacity retention.

[0018] According to a preferred embodiment, the substituent R 4 R 5 R 6 and R 9 They are independently selected from H and C1-C3 alkyl groups, and R 7 and R 8 They are selected independently of each other and for each unit n independently from H and C1-C3 alkyl groups.

[0019] According to a preferred embodiment, the substituent R 1 R 2 and R 3 Each is independently selected from H and C1-C3 alkyl groups; R is -OR', where R' is selected from H and C1-C3 alkyl groups. 10 Alkyl, the C1-C 10 The alkyl group is optionally substituted with one or more -OH, -CO2H, -SO3H, -PO3H, -OC(O)R”' or -C(O)OR”' groups or a five- or ten-membered heterocycle, wherein the five- or ten-membered heterocycle contains at least one nitrogen atom in its ring chain; R”' is selected from C1-C6 alkyl groups and C6-C6 alkyl groups optionally substituted with one or more -OH, -CO2H, -SO3H or -PO3H groups. 12 Aryl.

[0020] According to one implementation scheme, the substituent X is selected from C1-C1. 10 Alkyl and C4-C 10 Cycloalkyl.

[0021] According to a preferred embodiment, the composition further comprises copolymer P3, said copolymer P3 comprising monomer units generated from at least two monomers of formula (I), M3a and M3b: R 1 R 2 C=C(R 3 )C(O)R where R 1 R 2 and R 3 Independently selected from H and C1-C5 alkyl groups; R is selected from -NHC(CH3)2CH2C(O)CH3 and -OR', wherein R' is selected from H and C1-C5 alkyl groups. 18 Alkyl, the C1-C 18The alkyl group is optionally substituted with one or more -OH, -CO2H, -SO3H, -PO3H, -OC(O)R”' or -C(O)OR”' groups or a five- or ten-membered heterocycle, wherein the five- or ten-membered heterocycle contains at least one nitrogen atom in its ring chain; R”' is selected from C1-C6 alkyl groups and C6-C6 alkyl groups optionally substituted with one or more -OH, -CO2H, -SO3H or -PO3H groups. 12 Aryl.

[0022] According to a preferred embodiment, the fluorinated monomer M1a is selected from the following: 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); 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 can be hydrogen or F (CF2). m The value of 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; trifluoropropylene, tetrafluoropropylene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropylene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropylene and 2-trifluoromethyl-3,3,3-trifluoro-1-propylene or mixtures thereof.

[0023] According to a preferred embodiment, the fluorinated monomer M1a is vinylidene fluoride (VDF), and optionally the polymer P1 further comprises monomer units generated from monomer M1b, which is selected from: vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, such as perfluoro(methyl vinyl) ether, perfluoro(ethyl vinyl) ether, and perfluoro(propyl 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 has a value of 1, 2, 3 or 4, Equation R 2 The monomer of OCF=CH2, where R 2 It is F(CF2) p And p is 1, 2, 3 or 4, trifluoropropylene, tetrafluoropropylene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropylene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropylene and 2-trifluoromethyl-3,3,3-trifluoro-1-propylene or a mixture thereof.

[0024] According to a preferred embodiment, the fluoropolymer P1 has the following properties measured according to ASTM D-3835 method at 232°C and 100 seconds. -1 The melt viscosity measured below is greater than 1000 Pa·s. This allows for good electrode coating / coating, that is, good adhesion to the current collector coating / coating.

[0025] According to a preferred embodiment, the copolymer P2 has a content greater than or equal to 1000 g·mol⁻¹. -1 Number average molecular weight.

[0026] According to a preferred embodiment, in the composition, the weight ratio of P1 / P2 is 50 / 50 to 99 / 1, preferably 70 / 30 to 95 / 5.

[0027] According to another aspect, the present invention provides an adhesive for electrodes comprising the composition according to the present invention.

[0028] According to another aspect, the present invention provides an electrode composition comprising a binder, an active material, and optionally a conductive agent, an additive, or a mixture thereof, as described in the present invention.

[0029] According to a preferred embodiment, the electrode composition comprises a conductive agent composed of one or more materials selected from the group consisting of carbon black, graphite, carbon fiber, carbon nanotubes, carbon nanofibers, metal powders such as SUS powder and aluminum powder, and mixtures thereof.

[0030] According to a preferred embodiment, the active material is selected from the following: LiCoO2, Li(Ni,Co,Al)O2, Li (1+x) Ni a Mn b Co c O2 (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, 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 x and y independently represent real numbers between 0 and 2, and lithium metal phosphates with a composition represented by LiMPO4, where M represents Fe, Mn, Co, or Ni.

[0031] According to a preferred embodiment, the active material is selected from the following: lithium alloys, lithium metal, metal oxides, carbon materials such as graphite or hard carbon, silicon, silicone, silicon alloys, and Li4Ti5O. 12 .

[0032] According to another aspect, the present invention provides an electrode comprising a current collector and a layer composed of an electrode composition as described in the present invention; preferably, the layer is in contact with the current collector.

[0033] According to another aspect, the present invention provides a coating for a separator in a lithium-ion battery, comprising the composition described in the present invention.

[0034] According to another aspect, the present invention provides a separator for Li-ion batteries, comprising a coating according to the invention and inorganic particles optionally selected from: BaTiO3, Pb(Zr,Ti)O3, Pb 1-x La x Zr y O3(0 <x<1,0<y<1)、PbMg3Nb 2 / 3 O3, PbTiO3, hafnium dioxide (HfO or HfO2), SrTiO3, SnO2, CeO2, MgO, NiO, CaO, ZnO, Y2O3, boehmite (y-AlO(OH)), Al2O3, TiO2, SiC, ZrO2, borosilicates, BaSO4, nanoclays and mixtures thereof.

[0035] According to another aspect, the present invention provides a lithium-ion battery comprising a positive electrode, a negative electrode, and a separator, characterized in that at least one of these electrodes is an electrode according to the present invention or the separator is a separator according to the present invention.

[0036] According to another aspect, the composition according to the invention is used to prepare conductive polymers, solid electrolytes for fuel cells, hydrophilic coatings, hydrophobic coatings or UV-absorbing coatings; or as an adhesive for extruded multilayer structures in the form of membranes, sheets or tubes; or the copolymer is used as a coating on metals. Detailed Implementation

[0037] According to a first aspect, a composition comprising a fluoropolymer P1 and a copolymer P2 is provided. The fluoropolymer P1 comprises monomer units generated from a fluorinated monomer M1a. The copolymer P2 comprises formula (Ia)R 1 R 2 C=C(R 3 )C(O)R or (Ib)R 1 R 2 C=C(R 3 The copolymer P2 comprises monomer units of monomer M2a of formula (II) and monomer units derived from monomer M2b of formula (II). When the composition is used as a binder in an electrochemical device, the presence of monomer M2b in the copolymer P2 allows for improved adhesion while maintaining good capacity retention. According to a preferred embodiment, the P1 / P2 weight ratio is 50 / 50 to 99 / 1, advantageously 55 / 45 to 98 / 2, preferably 60 / 40 to 97 / 3, more preferably 65 / 35 to 96 / 4, particularly 70 / 30 to 95 / 5, even more particularly 80 / 20 to 95 / 5, and advantageously 85 / 15 to 95 / 5.

[0038] Polymer P1

[0039] According to a preferred embodiment, the fluoropolymer P1 contains at least one fluorinated monomer M1a in its chain, the fluorinated monomer M1a being selected from compounds containing a vinyl group capable of being opened for polymerization and containing at least one fluorine atom, fluoroalkyl group or fluoroalkoxy group directly attached to the vinyl group.

[0040] Preferably, the fluoropolymer P1 comprises monomer units generated from monomer M1a, wherein monomer M1a is 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 The value of 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, perfluorobutylethylene, pentafluoropropylene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropylene and 2-trifluoromethyl-3,3,3-trifluoro-1-propene or mixtures thereof.

[0041] In trifluoropropylene, 3,3,3-trifluoropropylene may be mentioned. In tetrafluoropropylene, 2,3,3,3-tetrafluoropropylene or 1,3,3,3-tetrafluoropropylene may be mentioned. In pentafluoropropylene, 1,1,3,3,3-pentafluoropropylene or 1,2,3,3,3-pentafluoropropylene may be mentioned. Chlorofluoroethylene may represent 1-chloro-1-fluoroethylene or 1-chloro-2-fluoroethylene. The 1-chloro-1-fluoroethylene isomer is preferred. Chlorotrifluoropropylene is preferably 1-chloro-3,3,3-trifluoropropylene or 2-chloro-3,3,3-trifluoropropylene.

[0042] Specifically, the fluoropolymer P1 comprises at least monomer units derived from monomer M1a, wherein monomer M1a is vinylidene fluoride. The fluoropolymer P1 may be a homopolymer or copolymer of vinylidene fluoride.

[0043] According to a particular implementation, the fluoropolymer P1 is a homopolymer of vinylidene fluoride.

[0044] According to another specific embodiment, the fluoropolymer P1 is a polymer comprising monomer units produced from monomer M1a (which is vinylidene fluoride) and monomer units produced from fluorinated monomer M1b (which can be copolymerized with vinylidene fluoride), or monomer units produced from non-fluorinated monomer M1c, or a mixture of the two.

[0045] According to one embodiment, the fluoropolymer P1 comprises monomer units generated from monomer M1a (which is vinylidene fluoride) and monomer units generated from fluorinated 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 The value of 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; perfluorobutylene (PFBE); trifluoropropylene, tetrafluoropropylene, hexafluoroisobutylene, perfluorobutylene, pentafluoropropylene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropylene and 2-trifluoromethyl-3,3,3-trifluoro-1-propylene or mixtures thereof. Preferably, the fluoropolymer P1 comprises monomer units derived from monomer M1a (which is vinylidene fluoride) and monomer units derived from fluorinated monomer M1b selected from: vinyl fluoride; 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-dioxacyclopentene); perfluoro(2,2-dimethyl-1,3-m-dioxacyclopentene); 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 formula CH2OCF=CF2, where n is 1, 2, 3, 4 or 5; the product of formula R'CH2OCF=CF2, where R' is hydrogen or F(CF2). z z is 1, 2, 3 or 4; the product of formula R''OCF=CH2, where R'' is F(CF2). z And z is 1, 2, 3, or 4; trifluoropropylene, tetrafluoropropylene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropylene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropylene, or 2-trifluoromethyl-3,3,3-trifluoro-1-propene, or mixtures thereof. In particular, the fluoropolymer P1 comprises monomer units generated from a monomer M1a that is vinylidene fluoride and monomer units generated from a fluorinated monomer M1b selected from trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, and hexafluoropropylene, or mixtures thereof.

[0046] According to another embodiment, the fluoropolymer P1 comprises monomer units generated from monomer M1a (which is vinylidene fluoride) and monomer units derived from formula R. a R b C=C(R c )C(O)R d The monomer unit generated from the non-fluorinated 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 and -OR d ', where R d Selected from H and C1-C 18 Alkyl, the C1-C18 Alkyl groups are optionally surrounded by one or more -OH, -CO2H, -SO3H, -PO3H, or -OC(O)R. d "or -C(O)OR d "A group or a five- or ten-membered heterocyclic substitution, wherein the five- or ten-membered heterocyclic contains at least one nitrogen atom in its ring chain; R" d "Selected from C1-C6 alkyl and C6-C groups optionally substituted with one or more -OH, -CO2H, -SO3H or -PO3H groups." 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, or 4-imidazolidinone ring. The heterocycle may be substituted with one or more C1-C5 alkyl groups. As described above, C1-C 18 The alkyl group is optionally 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 a 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 and -OR d ', where R d Selected from 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 '' or -C(O)OR d '' group or five- or ten-membered heterocyclic substitution, wherein the five- or ten-membered heterocyclic contains at least one nitrogen atom in its ring chain; R d 'Selected from C1-C6 alkyl and C6-C groups optionally substituted with one or more -OH, -CO2H, -SO3H or -PO3H groups.' 12 Aryl group. Preferably, the heterocycle is as defined above; in particular, the heterocycle is a 2-pyrrolidone, a δ-lactam, a succinimide, a 2-imidazolium ketone, or a 4-imidazolium ketone. Preferably, the substituent R... dThe monomer is selected from H, methyl, ethyl, propyl, n-butyl, isobutyl, tert-butyl, n-dodecyl, pentyl, isopentyl, hexyl, 2-ethylhexyl, lauryl, n-octyl, hydroxyethyl, hydroxybutyl, hydroxypropyl, and ethyl groups substituted with urea. In particular, the monomer M1c has the formula R. a R b C=C(R c )C(O)R d In which the substituent R a and R b It is H; R c It is H or CH3; R d For -OR d ', where R d The monomer M1c 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 particularly, the monomer M1c 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 of 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, alkyl groups having 1 to 8 carbon atoms are preferred, and alkyl groups having 1 to 5 carbon atoms are more preferred. The fluoropolymer P1 may comprise one or more monomer units derived from the monomer M1c as defined herein.

[0047] According to another embodiment, the fluoropolymer P1 comprises monomer units generated from a monomer M1a that is vinylidene fluoride, monomer units generated from a fluorinated monomer M1b, and monomer units derived from formula R. a R b C=C(R c )C(O)R d The monomer units are generated from the non-fluorinated monomer M1c; the monomers M1b and M1c are as defined above.

[0048] In the fluoropolymer P1, the weight content of monomer unit M1a is at least 50%, preferably at least 60%, more preferably greater than 70%, and advantageously greater than 80%. Preferably, when the fluorinated monomer M1a is vinylidene fluoride, the weight content of vinylidene fluoride monomer unit in the fluoropolymer P1 is at least 50%, preferably at least 60%, more preferably greater than 70%, and advantageously greater than 80%.

[0049] According to a particular embodiment, the fluoropolymer P1 can be fully or partially functionalized, which improves its adhesion to metals. Therefore, the fluoropolymer P1 can comprise monomer units having at least one functional group selected from: carboxylic acids, carboxylic anhydrides, carboxylic esters, epoxy (e.g., glycidyl), amides, hydroxyl groups, carbonyl groups, mercapto groups, sulfides, oxazolines, phenols, esters, ethers, siloxanes, sulfonic acids, sulfuric acids, phosphoric acids, and phosphonic acids, preferably at least one carboxylic acid or hydroxyl functional group.

[0050] According to techniques well known to those skilled in the art, functional groups are introduced through a chemical reaction, which may be a grafting or copolymerization of a fluorinated monomer with a monomer having at least one of the said functional groups and a vinyl functional group capable of copolymerizing with the fluorinated monomer.

[0051] According to one embodiment, the functional group has a carboxylic acid functional group, which is a group of (meth)acrylic acid selected from acrylic acid, methacrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyethylhexyl (meth)acrylate and acryloyloxypropyl succinate.

[0052] According to one embodiment, the unit with the carboxylic acid functional group further includes heteroatoms selected from oxygen, sulfur, nitrogen, and phosphorus.

[0053] According to one embodiment, functional groups are introduced by a transfer agent used in the synthesis process. The transfer agent is a polymer with a molecular weight of less than or equal to 20,000 g / mol, having functional groups selected from: carboxylic acids, carboxylic anhydrides, carboxylic esters, epoxy groups (such as glycidyl groups), amides, hydroxyl groups, carbonyl groups, mercapto groups, sulfides, oxazoline groups, phenolic groups, esters, ethers, siloxanes, sulfonic acid groups, sulfate groups, phosphate groups, or phosphonic acid groups. Acrylic oligomers are examples of this type of transfer agent. According to a preferred embodiment, the transfer agent is an acrylic oligomer with a molecular weight of less than or equal to 20,000 g / mol. Alternatively, functional groups can be introduced by an oligomer or polymeric compound containing said functional groups and mixed with the fluoropolymer P1. The oligomer or polymeric compound can be impregnated into, mixed with, or tightly mixed with the fluoropolymer P1. In this case, the functional group can be generated from a (meth)acrylic acid compound selected from acrylic acid, methacrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyethylhexyl (meth)acrylate, and acryloyloxypropyl succinate. For example, the functional group can be an oligomer or polymer comprising monomer units generated from monomers selected from acrylic acid, methacrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyethylhexyl (meth)acrylate, 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. Weight-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 polymethyl methacrylate samples with molecular weights ranging from 535 to 2,210,000 g / mol were used as calibration standards. The oligomer or polymer was preferably added during the production of the fluoropolymer P1. The functional group content of PVDF was at least 0.01 mol%, preferably at least 0.1 mol%, and at most 15 mol%, preferably at most 10 mol%.

[0054] The fluoropolymer P1 preferably has a high molecular weight. As used herein, the term "high molecular weight" should be understood to mean that it is produced according to the ASTM D-3835 method at 232°C and 100 seconds. -1 Fluoropolymer P1 with a measured melt viscosity greater than 100 Pa·s, advantageously greater than 500 Pa·s, preferably greater than 1000 Pa·s, more preferably greater than 2000 Pa·s, particularly greater than 2500 Pa·s, and even more particularly greater than 3000 Pa·s.

[0055] The fluoropolymer P1 used in this invention can be obtained by known polymerization methods, such as emulsion polymerization or suspension polymerization. According to a preferred embodiment, the fluoropolymer P1 is prepared by emulsion polymerization in the presence of a non-fluorinated surfactant. Therefore, the fluoropolymer P1 may contain 10 ppm to 2% by weight of a non-fluorinated surfactant comprising polyethylene glycol or polypropylene glycol units. Preferably, the non-fluorinated surfactant has an HLB value of 1 to 20, particularly an HLB value of 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 molecular weight of 5000 to 10000 g·mol⁻¹. -1 The weight-average molecular weight. Alternatively, the 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 molecular weight of 500 to 2500 g·mol⁻¹. -1 The weight-average molecular weight.

[0056] According to a preferred embodiment, the fluoropolymer P1 is prepared by suspension polymerization.

[0057] The fluoropolymer P1 can be in the form of a latex, with a solids content typically from 10% to 60% (by weight), preferably from 10% to 50%, and a weight-average particle size of less than 1 micrometer, preferably less than 1000 nanometers, more preferably less than 800 nanometers, and even more preferably less than 600 nanometers. The weight-average particle size is typically at least 20 nm, preferably at least 50 nm, and advantageously, the average size is in the range of 100 to 400 nm. The polymer particles can form aggregates with a weight-average size of 1 to 30 micrometers, preferably 2 to 10 micrometers. During formulation and application to a substrate, the aggregates can be broken down into discrete particles.

[0058] The fluoropolymer P1 can be in powder form. The powder is obtained from a latex, which, for example, undergoes a drying and optional granulation stage.

[0059] According to some embodiments, the vinylidene fluoride contained in the fluoropolymer P1 is bio-based. The term "bio-based" means "produced from biomass." This allows for an improvement in the polymer's ecological footprint. A bio-based VDF is characterized by a renewable carbon content, i.e., carbon derived from a natural source of biological material or biomass, at least 1 atomic%, as determined by the 14C content according to standard NFEN 16640. The term "renewable carbon" indicates that the carbon is of a natural source and derived from biological material (or biomass), as shown below. According to 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%.

[0060] copolymer P2

[0061] According to a preferred embodiment, the copolymer P2 comprises at least one of formula (Ia)R 1 R 2 C=C(R 3 )C(O)R or (Ib)R 1 R 2 C=C(R 3 The monomer unit generated by monomer M2a of R'' and the monomer unit generated by monomer M2b of formula (II):

[0062]

[0063] in:

[0064] Substituent R 1 R 2 and R 3 Each of the elements is independently selected from H, C1-C5 alkyl groups, and NH2; R” is selected from C6-C 12 Aryl and CN; R is selected from -NHC(CH3)2CH2C(O)CH3 and -OR', where R' is selected from H and C1-C 18 Alkyl, the C1-C 18 The alkyl group is optionally substituted with one or more -OH, -CO2H, -SO3H, -PO3H, -OC(O)R”' or -C(O)OR”' groups or a five- or ten-membered heterocycle, wherein the five- or ten-membered heterocycle contains at least one nitrogen atom in its ring chain; R”' is selected from C1-C6 alkyl groups and C6-C6 alkyl groups optionally substituted with one or more -OH, -CO2H, -SO3H or -PO3H groups. 12 Aryl;

[0065] Substituent R 4R 5 R 6 and R 9 They are independently selected from H and C1-C5 alkyl groups;

[0066] R 7 and R 8 They are selected independently of each other and for each unit n from H and C1-C5 alkyl groups;

[0067] X is selected from C1-C 18 Alkyl and C4-C 18 cycloalkyl;

[0068] n is an integer from 1 to 10, preferably from 1 to 5; in particular, n is 1.

[0069] Therefore, the monomer M2a can have the formula (Ia)R 1 R 2 C=C(R 3 )C(O)R, where the substituent R 1 R 2 and R 3 Independently selected from H and C1-C5 alkyl groups; R is selected from -NHC(CH3)2CH2C(O)CH3 and -OR', wherein R' is selected from H and C1-C5 alkyl groups. 18 Alkyl, the C1-C 18 The alkyl group is optionally substituted with one or more -OH, -CO2H, -SO3H, -PO3H, -OC(O)R''' or -C(O)O-R''' groups or a five- or ten-membered heterocycle, wherein the five- or ten-membered heterocycle contains at least one nitrogen atom in its ring chain; R''' is selected from C1-C6 alkyl groups and C6-C6 alkyl groups optionally substituted with one or more -OH, -CO2H, -SO3H or -PO3H groups. 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, or 4-imidazolidinone ring. The heterocycle may be substituted with one or more C1-C5 alkyl groups. As described above, C1-C 18 The alkyl group is optionally 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 a 2-pyrrolidone, δ-lactam, succinimide, 2-imidazolidineone, or 4-imidazolidineone. Advantageously, the monomer M2a can have the formula (Ia)R 1 R 2 C=C(R 3 )C(O)R, where the substituent R1 R 2 and R 3 Each is independently selected from H and C1-C5 alkyl groups; R is -OR', where R' is selected from H and C1-C5 alkyl groups. 18 Alkyl, the C1-C 18 The alkyl group is optionally substituted with one or more -OH, -CO2H, -SO3H, -PO3H, -OC(O)R”' or -C(O)OR”' groups or a five- or ten-membered heterocycle, wherein the five- or ten-membered heterocycle contains at least one nitrogen atom in its ring chain; R”' is selected from C1-C6 alkyl groups and 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; in particular, the heterocycle is 2-pyrrolidone, δ-lactam, succinimide, 2-imidazolium ketone, or 4-imidazolium ketone. The substituent R' may be selected from H, methyl, ethyl, propyl, n-butyl, isobutyl, tert-butyl, n-dodecyl, pentyl, isopentyl, hexyl, 2-ethylhexyl, lauryl, n-octyl, hydroxyethyl, hydroxybutyl, hydroxypropyl, 2-pyrrolidone, δ-lactam, succinimide, 2-imidazolium ketone, 4-imidazolium ketone, and ethyl groups substituted with urea. Preferably, the monomer M2a has the formula (Ia)R. 1 R 2 C=C(R 3 )C(O)R, where the substituent R 1 and R 2 It is H; R 3 It is H or CH3; R is -OR', where R' is selected from H and Cl-C. 18 Alkyl, the C1-C 18 The alkyl group is optionally substituted with one or more -OH, -CO2H, -SO3H, -PO3H, -OC(O)R”' or -C(O)OR”' groups; R”' is selected from C1-C6 alkyl and C6-C6 alkyl groups optionally substituted with one or more -OH, -CO2H, -SO3H or -PO3H groups. 12 Aryl. More preferably, the monomer M2a has the formula (Ia)R 1 R 2 C=C(R 3 )C(O)R, where the substituent R 1 and R 2 It is H; R 3 It is H or CH3; R is -OR', where R' is selected from H and Cl-C. 15 Alkyl, the C1-C 15The alkyl group is optionally substituted with one or more -OH, -CO2H, -SO3H, -PO3H, -OC(O)R”' or -C(O)OR”' groups; R”' is selected from C1-C6 alkyl and C6-C6 alkyl groups optionally substituted with one or more -OH, -CO2H, -SO3H or -PO3H groups. 12 Aryl. Specifically, the monomer M2a has the formula (Ia)R 1 R 2 C=C(R 3 )C(O)R, where the substituent R 1 and R 2 It is H; R 3 It is H or CH3; R is -OR', where R' is selected from H and Cl-C. 10 Alkyl, the C1-C 10 The alkyl group is optionally substituted with one or more -OH, -CO2H, -SO3H, -PO3H, -OC(O)R”' or -C(O)OR”' groups; R”' is selected from C1-C6 alkyl and C6-C6 alkyl groups optionally substituted with one or more -OH, -CO2H, -SO3H or -PO3H groups. 12 Aryl. More specifically, the monomer M2a 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 acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-dodecyl methacrylate, pentyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, methyl methacrylate, ethyl methacrylate, ethyl methacrylate, propyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, methyl methacrylate, ethyl ... Urea acrylate, monomers of the following formulas: CH2=CH(CO2CH2CH2CO2H), CH2=CH(CO2CH2CH2-OC(O)-CH2CH2CO2H), CH2=CH((CO2CH2CH2-OC(O)-C6H4CO2H), CH2=CH(CO2CH2CH2CH2CH(CO2H)CH2CH2CO2H); and mixtures thereof. Among these, the monomer M2a having an alkyl group having 1 to 8 carbon atoms is preferred, and more preferably an alkyl group having 1 to 5 carbon atoms. The copolymer P2 may comprise one or more monomer units generated from the monomer M2a as defined herein; for example, M2a may be a mixture between methyl methacrylate and methacrylic acid.

[0070] Alternatively, the monomer M2a may have the formula (Ib)R 1 R 2 C=C(R 3 )R” where the substituent R 1 R 2 and R 3 Each of the elements is independently selected from H, C1-C5 alkyl groups, and NH2; R” is selected from C6-C 12 Aryl and CN. Preferably, in this embodiment, the monomer M2a may have the formula (Ib)R 1 R 2 C=C(R 3 )R", where the substituent R 1 R 2 and R 3 Each is independently selected from H and C1-C3 alkyl groups and NH2; R” is selected from C6-C 12 Aryl and CN.

[0071] Monomer M2b has formula (II):

[0072]

[0073] Wherein the substituent R 4 R 5 R 6 and R 9 Independently selected from H and C1-C5 alkyl groups; R 7 and R 8 Independently selected from H and C1-C5 alkyl groups, and independently selected for each unit n; X selected from C1-C5 alkyl groups. 18 Alkyl and C4-C 18 Cycloalkyl; n is an integer from 1 to 10, preferably from 1 to 5; in particular, n is 1.

[0074] As used in this application, the terms "alkyl" or "cycloalkyl" refer to straight-chain or branched alkyl or cycloalkyl groups.

[0075] Advantageously, the monomer M2b has the formula (II) as defined above, wherein the substituent R 4 R 5 R 6 and R 9 Independently selected from H and C1-C3 alkyl groups; R 7 and R 8 Independently selected from H and C1-C3 alkyl groups, and independently selected for each unit n; X is selected from C1-C3 alkyl groups. 15 Alkyl and C4-C 15 Cycloalkyl; n is an integer from 1 to 10, preferably from 1 to 5; in particular, n is 1.

[0076] Preferably, the monomer M2b has the formula (II) as defined above, wherein the substituent R 4 R 5 R 6 and R 9 They are independently selected from H and CH3; R 7 and R 8 Independently selected from H and CH3, and independently for each unit n; X selected from C1-C 10 Alkyl and C4-C 10 Cycloalkyl; n is an integer from 1 to 10, preferably from 1 to 5; in particular, n is 1.

[0077] More preferably, the monomer M2b has the formula (II) as defined above, wherein the substituent R 4 R 5 and R 9 It is H; R 6 It is H or CH3; R 7 and R 8 Independently selected from H and CH3, and independently for each unit n; X selected from C1-C 10 Alkyl and C4-C 10 Cycloalkyl; n is an integer from 1 to 10, preferably from 1 to 5; in particular, n is 1.

[0078] Specifically, the monomer M2b has the formula (II) as defined above, wherein the substituent R 4 R 5 and R 9 It is H; R 6 It is H or CH3; R 7 and R 8 Independently selected from H and CH3 for each unit n; X selected from C2-C8 alkyl and C5-C8 cycloalkyl; n is an integer from 1 to 10, preferably from 1 to 5; in particular, n is 1. More particularly, the monomer M2b has formula (II) as defined above, wherein the substituent R 4 R 5 and R 9 It is H; R 6 It is H or CH3; R 7 and R 8 Each and each unit n is independently selected from H and CH3; X is selected from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, isopropyl, tert-butyl, isobutyl, sec-butyl, isopentyl, neopentyl, tert-pentyl, dimethylpropyl, trimethylpentyl, tetramethylcyclobutyl, cyclohexyl and dimethylcyclohexyl; n is an integer from 1 to 10, preferably from 1 to 5; in particular, n is 1.

[0079] Preferably, the copolymer P2 contains at least 50% by weight, advantageously at least 60% by weight, preferably at least 70% by weight, more preferably at least 75% by weight, particularly at least 80% by weight, and even more particularly at least 85% by weight of monomer M2a, based on the total weight of the copolymer P2.

[0080] Preferably, the copolymer P2 contains less than 50% by weight, advantageously less than 40% by weight, preferably less than 30% by weight, more preferably less than 25% by weight, particularly less than 20% by weight, and even more particularly less than 15% by weight of monomer M2b, based on the total weight of the copolymer P2.

[0081] Alternatively, the copolymer P2 may contain at least 50 mol%, advantageously at least 60 mol%, preferably at least 70 mol%, more preferably at least 75 mol%, particularly at least 80 mol%, and even more particularly at least 85 mol% of monomer M2a, based on the copolymer P2. Alternatively, the copolymer P2 may contain less than 50 mol%, advantageously less than 40 mol%, preferably less than 30 mol%, more preferably less than 25 mol%, particularly less than 20 mol%, and even more particularly less than 15 mol% of monomer M2b, based on the copolymer P2.

[0082] When the copolymer P2 may further comprise monomer units generated from monomer M2c, the monomer M2c may be:

[0083] -(A) Alkenyl compounds having functional groups, or

[0084] -(B) Alkenyl compounds that do not have functional groups.

[0085] Alkenyl compounds (A) containing functional groups include, for example, α,β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, fumaric acid, crotonic acid, itaconic acid, etc.; vinyl ester compounds such as vinyl acetate, vinyl neodecanoate, etc.; amide compounds such as acrylamide, methacrylamide, N-methacrylamide, N-methylmethacrylamide, N-hydroxymethylacrylamide, N-hydroxymethylmethacrylamide, N-alkylacrylamide, N-alkylmethylacrylamide, N,N-dialkylacrylamide, N,N-dialkylmethylacrylamide, diacetone acrylamide, etc. The compounds include amines, sodium 2-acrylamido-2-methyl-1-propanesulfonate; acrylates, such as 2-hydroxyethyl acrylate, N-dialkylaminoethyl acrylate, glycidyl acrylate, n-dodecyl acrylate, fluoroalkyl acrylate, etc.; methacrylates, such as dialkylaminoethyl methacrylate, fluoroalkyl methacrylate, 2-hydroxyethyl methacrylate, n-octyl methacrylate, tert-butyl methacrylate, glycidyl methacrylate, ethylene glycol dimethacrylate, etc.; maleic anhydride; and alkenyl glycidyl ether compounds, such as allyl glycidyl ether, etc. Preferred compounds include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, N-hydroxymethylacrylamide, N-hydroxymethylmethacrylamide, diacetone acrylamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and allyl glycidyl ether. These compounds can be used alone or as a mixture of two or more. Alkenyl compounds (B) that do not have functional groups include, for example, conjugated dienes such as 1,3-butadiene, isoprene, etc.; divinyl hydrocarbon compounds such as divinylbenzene, etc.; and alkenyl cyanides such as acrylonitrile, methacrylonitrile, etc. Among these, 1,3-butadiene and acrylonitrile are preferred compounds. These compounds can be used alone or as a mixture of two or more.

[0086] copolymer P3

[0087] According to a preferred embodiment, the composition may further comprise copolymer P3. The copolymer P3 comprises at least two compounds of formula R. 10 R 11 C=C(R 12 )C(O)R 13 The monomer units obtained from monomers M3a and M3b, wherein the substituent R 10 R 11 and R 12 Independently selected from H and C1-C5 alkyl groups; R 13 Selected from -NHC(CH3)2CH2C(O)CH3 and -OR 14 , where R 14 Selected from H and C1-C 18 Alkyl, the C1-C 18Alkyl groups are optionally surrounded by one or more -OH, -CO2H, -SO3H, -PO3H, or -OC(O)R. 14’ or -C(O)OR 14’ A group or a five- or ten-membered heterocyclic substitution, wherein the five- or ten-membered heterocyclic contains at least one nitrogen atom in its ring chain; R 14’ Selected from C1-C6 alkyl and C6-C groups optionally substituted with one or more -OH, -CO2H, -SO3H or -PO3H groups. 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, or 4-imidazolidinone ring. The heterocycle may be substituted with one or more C1-C5 alkyl groups. As described above, C1-C 18 The alkyl group is optionally replaced by the heterocycle. The latter can be bonded to the alkyl chain via a nitrogen atom or any other atom that forms the heterocycle. Preferably, the heterocycle is a 2-pyrrolidone, a δ-lactam, a succinimide, a 2-imidazolidineone, or a 4-imidazolidineone.

[0088] The monomers M3a and M3b are different from each other. The monomers M3a and M3b preferably have the formula R. 10 R 11 C=C(R 12 )C(O)R 13 In which the substituent R 10 R 11 and R 12 Independently selected from H and C1-C5 alkyl groups; R 13 Selected from -NHC(CH3)2CH2C(O)CH3 and -OR 14 , where R 14 Selected from 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. 14’ or -C(O)OR 14’ A group or a five- or ten-membered heterocyclic substitution, wherein the five- or ten-membered heterocyclic substitution contains at least one nitrogen atom in its ring chain; R 14’ Selected from C1-C6 alkyl and C6-C groups optionally substituted with one or more -OH, -CO2H, -SO3H or -PO3H groups. 12Aryl group. Preferably, the heterocycle is as defined above; in particular, the heterocycle is a 2-pyrrolidone, a δ-lactam, a succinimide, a 2-imidazolium ketone, or a 4-imidazolium ketone. The monomers M3a and M3b independently have the formula R. 10 R 11 C=C(R 12 )C(O)R 13 In which the substituent R 10 and R 11 It is H; R 12 It is H or CH3; R 13 Yes - OR 14 , where R 14 The monomers are selected from H, methyl, ethyl, propyl, n-butyl, isobutyl, tert-butyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, 2-pyrrolidone, δ-lactam, succinimide, 2-imidazolium, and 4-imidazolium. More specifically, the monomers M3a and M3b are independently selected from 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 acrylate, hydroxypropyl acrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxyethyl methacrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methyl tert-butyl acrylate, dodecyl methacrylate, pentyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, urea methacrylate, monomers of the formula CH2=CH(CO2CH2CH2CO2H), CH2=CH(CO2CH2CH2-OC(O)-CH2CH2CO2H), CH2=CH(CO2CH2CH2-OC(O)-C6H4CO2H), CH2=CH(CO2CH2CH2CH2CH(CO2H)CH2CH2CO2H); and mixtures thereof.

[0089] According to the preferred embodiment, the weight ratio of P1 / P3 is 70 / 30 to 99 / 1, more particularly 80 / 20 to 99 / 1, and advantageously 85 / 15 to 99 / 1.

[0090] The copolymers P2 and P3 according to the invention can be obtained by polymerizing monomers according to known polymerization methods (e.g., emulsion polymerization or suspension polymerization).

[0091] Preferably, the copolymers P2 and P3 independently have a glass transition temperature of less than or equal to 230°C. Advantageously, the copolymers P2 and P3 have a glass transition temperature of less than or equal to 220°C, preferably less than 200°C, more preferably less than 180°C, particularly less than 160°C, and even 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 random copolymers: 1 / Tg,copo ≈ ∑i ωi / Tg,i; Tg,copo is the glass transition temperature of the copolymer; Tg,i is the glass transition temperature of the homopolymer i corresponding to each comonomer; ωi is the weight fraction of monomer i constituting the copolymer. The weight fraction is not expressed in units. The glass transition temperature is expressed in Kelvin. The temperature is then converted to Celsius.

[0092] According to a preferred embodiment, the copolymers P2 and P3 independently have a content greater than or equal to 1000 g·mol⁻¹. -1 Advantageously greater than or equal to 3000 g·mol -1 Preferably greater than or equal to 5000 g·mol⁻¹ -1 More preferably greater than or equal to 10,000 g·mol⁻¹ -1 Especially greater than or equal to 50,000 g·mol -1 More specifically, greater than or equal to 100,000 g·mol⁻¹ -1 In a favorable manner, greater than or equal to 150,000 g·mol⁻¹ -1 The number-average molecular weight. Therefore, the number-average molecular weight of the copolymer P2 can be greater than or equal to 1000 g·mol⁻¹. -1 Advantageously greater than or equal to 3000 g·mol -1 Preferably greater than or equal to 5000 g·mol⁻¹ -1 More preferably greater than or equal to 10,000 g·mol⁻¹ -1 Especially greater than or equal to 50,000 g·mol -1 More specifically, greater than or equal to 100,000 g·mol⁻¹ -1 In a favorable manner, greater than or equal to 150,000 g·mol⁻¹ -1 This allows for the acquisition of a good electrode coating, meaning an electrode coating that adheres well to the current collector. The copolymer P3 may have a content greater than or equal to 1000 g·mol⁻¹. -1 Advantageously greater than or equal to 3000 g·mol -1 Preferably greater than or equal to 5000 g·mol⁻¹ -1 More preferably greater than or equal to 10,000 g·mol⁻¹ -1Especially greater than or equal to 50,000 g·mol -1 More specifically, greater than or equal to 100,000 g·mol⁻¹ -1 In a favorable manner, greater than or equal to 150,000 g·mol⁻¹ -1 The number-average molecular weights were determined. The molecular weights of copolymers P2 and P3 were determined by size exclusion chromatography (SEC). Test samples corresponding to 90 mg of polymer solution were introduced into 10 mL flasks. A mobile phase containing 0.04% dimethylformamide (DMF) was added to a total weight of 10 g. The mobile phase composition was as follows: NaHCO3: 0.05 mol / L, NaNO3: 0.1 mol / L, triethanolamine: 0.02 mol / L, NaN3: 0.03 wt%. The SEC line consisted of a Waters 510 isocratic pump (flow rate adjusted to 0.8 mL / min), a Waters 717+ autosampler, an oven containing a Waters Ultrahydrogel Guard Column pre-column (6 cm long, 40 mm inner diameter), followed by a Waters Ultrahydrogel linear column (30 cm long, 7.8 mm inner diameter). Detection was performed using a Waters 410 RI differential refractometer. The oven was heated to 60°C, and the refractometer was heated to 45°C. The SEC apparatus was calibrated using a series of sodium polyacrylate standards provided by PolymerStandards Service, with peak molecular weights at 1000 g / mol and 1.10 g / mol. 6 The polydispersity index is between 1.4 and 1.7, with g / mol values ​​between g / mol and g / mol values ​​between g / mol. The calibration curves are linear and take into account corrections obtained using the flow marker, dimethylformamide (DMF).

[0093] Method for preparing the composition

[0094] The composition can be prepared by different methods. The fluoropolymer P1 and the copolymer P2 and optionally P3 can be mixed with each other in powder or latex form.

[0095] Alternatively, the composition may be in the form of an interpenetrating polymer network (IPN) or a semi-interpenetrating polymer network (semi-IPN). An interpenetrating polymer network is defined as a network in which polymers are at least partially interwoven at the molecular level but not covalently bonded to each other and can only be separated upon the breaking of chemical bonds. A semi-interpenetrating polymer network (semi-IPN) comprises one or more polymer networks and one or more linear or branched polymers, characterized in that at least one network is permeated at the molecular level by at least some linear or branched macromolecules. A mixture of two or more pre-formed polymer networks is not an interpenetrating polymer network or a semi-interpenetrating polymer network. In this case, the composition may be prepared by a method comprising the following stages:

[0096] a) Provide a reactor containing the fluoropolymer P1;

[0097] b) Add at least one monomer M2a, at least one monomer M2b and optional monomer M2c as defined above;

[0098] c) Polymerize the at least one monomer M2a and at least one monomer M2b, and optionally the monomer M2c, to obtain the composition according to the invention;

[0099] d) Optionally dry and grind the product obtained in stage c).

[0100] In stage a), the fluoropolymer P1 is preferably in the form of latex.

[0101] During stage b), polymer P1 is contacted with at least one monomer M2a, M2b, and optionally monomer M2c for a sufficient period of time to impregnate the particles of fluoropolymer P1 before polymerization. This contact period can be at least 5 minutes, preferably 10 minutes, and particularly at least 15 minutes. The longer the contact between the monomers and fluoropolymer P1 lasts, the more thoroughly polymer P1 and copolymer P2 are mixed; this can improve the adhesive properties of the composition.

[0102] Phase c) is preferably carried out in the presence of water. Polymerization phase c) is carried out in the presence of an initiator. The initiator may be a persulfate-type initiator, such as sodium persulfate, potassium persulfate, barium persulfate, or ammonium persulfate; an alkali metal bisulfite; a peroxide, such as benzoyl peroxide or dicumyl peroxide; a hydroperoxide, such as methyl hydroperoxide or tert-butyl hydroperoxide; a ketol (azo alcohol), such as benzoin; a peracetic acid ester, such as methyl peracetate or tert-butyl peracetate; a benzoate ester, such as tert-butyl perbenzoate; a peroxyoxalate ester, such as dimethyl peroxyoxalate or di(tert-butyl) peroxyoxalate; or an azo compound, such as azobisisobutyronitrile or dimethyl azobisisobutyrate. Based on the weight of M2a, M2b, and optionally M2c, the initiator is preferably added at a content of 0.005% to 1% by weight. Phase c) can be carried out at a temperature of 20°C to 160°C. Stage c) can be carried out at a pressure of 280 to 20,000 kPa. Preferably, stages b) and c) are carried out under stirring. The polymerization product obtained in stage c) is optionally dried in stage d) to obtain a powder. The drying stage can be carried out by spray drying or a combination of both (spray drying), preferably at a temperature of 50°C to 220°C. If it is desired to obtain the composition in powder form, the latter can also be obtained by grinding techniques, such as cryogenic grinding, in which the mixture is brought to a temperature below ambient temperature by, for example, 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 a selection or screening process and / or by grinding to obtain the desired particle size distribution.

[0103] use

[0104] The composition described in this patent application can be used in many applications. Therefore, the composition can be used as a binder for electrodes (cathodes or anodes) or as a coating (paint) for diaphragms.

[0105] The composition according to the invention can be used as a binder for electrodes. Therefore, the invention provides an electrode composition comprising the composition according to the invention, an active material, and optionally a conductive agent.

[0106] In a preferred embodiment, the electrode composition has the following weight composition:

[0107] a. 50% to 99.95% active material, preferably 50% to 99%.

[0108] b. 0% to 25% conductive agent, preferably 0.5% to 25%.

[0109] c. 0.05% to 25% of the adhesive according to the invention, preferably 0.5% to 25%.

[0110] d. 0% to 5% of at least one additive selected from plasticizers, ionic liquids, dispersants for conductive additives, and flow aids.

[0111] The sum of all these percentages is 100%.

[0112] The conductive agent in the electrode consists of one or more materials that can improve conductivity. Some examples include carbon black, such as acetylene black or Ketjen black; carbon fibers, such as carbon nanotubes, carbon nanofibers, or vapor-grown carbon fibers; or metal powders, such as SUS powder and aluminum powder.

[0113] The active material in the electrode composition is a material capable of storing and releasing lithium ions.

[0114] In a preferred embodiment, the electrode is a negative electrode. Specifically, for the negative electrode, the active material is selected from lithium alloys, lithium metal, metal oxides, carbon materials such as graphite or hard carbon, silicon, silicon alloys, and Li₄Ti₅O. 12 There are no particular restrictions on the form of the negative electrode active material, but particles are preferred.

[0115] In another preferred embodiment, the electrode is a positive electrode. Preferably, for the positive electrode, the active material is selected from the following: LiCoO2, Li(Ni,Co,Al)O2, Li (1+x) Ni a Mn b Co c O2 (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, 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 yx and y independently represent real numbers between 0 and 2, and a lithium metal phosphate having a composition represented by LiMPO4, where M represents Fe, Mn, Co, or Ni. The form of the positive electrode active material is not particularly limited, but particles are preferred. Furthermore, the surface of each of the above materials can be coated. The coating material is not particularly limited, as long as it has lithium-ion conductivity and contains materials capable of being retained on the surface of the active material in the form of a coating. Examples of coating materials include LiNbO3 and Li4Ti5O3. 12 And Li3PO4.

[0116] The electrode composition can be deposited on at least one surface of the current collector to form the electrode. This deposition can be carried out in the presence of an organic solvent, water, or a mixture of both, or by a solvent-free method, i.e., by a dry-coating electrode production method. The organic solvent may be selected from N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), triethyl phosphite, triethyl phosphate, acetone, cyclopentanone, tetrahydrofuran, methyl ethyl ketone (MEK), methyl isobutyl ketone (MiBK), ethyl acetate (EA), butyl acetate (BA), ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), γ-butyrolactone, and N-butylpyrrolidone; and mixtures thereof.

[0117] The method for preparing the dry-coated electrode includes the following stages:

[0118] - The active material in powder form, the binder according to the invention, and optionally the conductive agent in powder form, the additive in powder form, or both, are mixed to form the electrode composition according to the invention;

[0119] - The electrode composition is deposited on the current collector to fabricate an electrode, and

[0120] - The electrodes may optionally be solidified by thermomechanical treatment.

[0121] Therefore, the dry-coated electrode is prepared according to a "solvent-free" method, that is, a method that does not require a stage of evaporating residual solvent after the deposition stage, because all components are mixed in dry powder form, and the deposition is also carried out without solvent. Thermomechanical treatment refers to applying mechanical pressure to the electrode at a given temperature. This thermomechanical treatment can be carried out, for example, by a calendering apparatus including rollers that can be heated, or by a plate press that can also be heated.

[0122] Various methods for solvent-free mixing of electrode compositions prior to the deposition stage on the current collector may be mentioned (but not limited to): mixing by stirring, air jet mixing, high shear mixing, mixing with a V-type mixer, mixing with a screw mixer, double cone mixing, drum mixing, conical mixing, double Z-arm mixing, mixing in a fluidized bed, mixing in a planetary mixer, mixing by mechanical fusion, mixing by extrusion, mixing by calendering, and mixing by grinding.

[0123] According to one embodiment, after the powder mixing stage, the electrode is manufactured by solvent-free spraying, by depositing the electrode composition 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 rotating metering roller, or by calendering.

[0124] According to one embodiment, after deposition on a metal substrate via solvent-free spraying (pneumatic spraying, electrostatic spraying, immersion in a fluidized bed powder, spraying, electrostatic screen printing, deposition with a rotating brush, or deposition with a rotating metering roller), electrode consolidation is performed by calendering. This method involves applying pressure to the electrode using two optionally heated rollers. The consolidation stage is optional. Its implementation depends on the technique used to deposit the components onto the electrode. Therefore, when the deposition stage is performed by calendering, this consolidation stage is optional because calendering allows for simultaneous electrode deposition and consolidation.

[0125] According to one embodiment, the electrode is manufactured via a two-stage solvent-free process following a powder mixing stage. The first stage involves manufacturing a self-supporting film from a premixed formulation using thermomechanical methods (e.g., extrusion, calendering, or hot pressing). In the second stage, the self-supporting film is laminated onto a metal substrate using a combination of temperature and pressure methods, such as calendering or hot pressing.

[0126] According to one embodiment, after the powder mixing stage, the electrode is manufactured using a calendering process via a solvent-free method. This allows the film formation stage and the coating transfer stage to the current collector to be performed in a single stage, i.e., without the need for a stage of manufacturing a self-supporting film. For this purpose, the calender used has multiple rolls (at least three). The powder obtained after the mixing stage is introduced between the first two rolls, which are typically heated and rotate at different speeds to shear the powder. The coating, formed and held adhering to the fastest roll, is then directly laminated onto the current collector using a third roll. If desired, the resulting electrode can then be passed through the calender again to adjust its porosity or thickness.

[0127] According to another aspect of the invention, the composition according to the invention can be used as a coating in a separator disposed between two electrodes. The separator according to the invention comprises a coating containing (preferably composed of) the composition according to the invention, optionally disposed on one or both sides of a porous carrier. In this case, the coating is used to coat the carrier of the separator in a single layer or multiple layers on at least one side. There are no particular limitations on the choice of the carrier coated with the coating of the invention, as long as it is a porous substrate with pores. When it comprises multiple layers, the coating as described in the invention is disposed on the outer surface of the carrier, i.e., on the surface that will first come into contact with the electrolyte composition used in the battery. Advantageously, the coating is applied to the carrier by an aqueous approach or by a solvent approach. 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 web forming a porous web, for example, a web obtained by direct spinning or meltblowing (spunbond or meltblown type) or electrospinning. Examples of porous substrates used as carriers in this invention include, but are not limited to: polyolefins, polyethylene terephthalate, polybutylene terephthalate, polyesters, polyacetals, polyamides, polycarbonates, polyimides, polyetheretherketones, polyethersulfones, poly(phenylene ether), poly(phenylene sulfide), polyethylene naphthalate, or mixtures thereof. However, other heat-resistant engineering plastics may be used without particular limitation. Nonwoven materials made from natural or synthetic materials may also be used as the substrate for the diaphragm. The porous substrate typically has a thickness of 1 to 50 μm and is typically a membrane or cast nonwoven obtained by extrusion and stretching (wet or dry). The porous substrate preferably has a porosity of 5% to 95%. The average pore size (diameter) is preferably 0.001 to 50 μm, more preferably 0.01 to 10 μm. The carrier may also be aluminum or aluminum coated with a polymer layer.

[0128] In addition to the composition described above, the coating for the separator may contain inorganic particles, which are used to form micropores (gaps between inorganic particles) in the coating. The addition of inorganic particles may also contribute to heat resistance or improve wettability. According to one embodiment, the coating comprises inorganic particles accounting for 50% to 99% of the coating weight. These inorganic particles must be electrochemically stable (not subject to oxidation and / or reduction within the voltage range used). Furthermore, the powdered inorganic material preferably has high ionic conductivity. Low-density materials are preferred over higher-density materials because they can reduce the weight of the produced battery. The dielectric constant is preferably equal to or greater than 5. According to one embodiment, the inorganic particles are selected from: BaTiO3, Pb(Zr,Ti)O3, Pb 1-x La x Zr y O3(0 <x<1,0<y<1)、PbMg 1 / 3 Nb 2 / 3O3, PbTiO3, hafnium oxide (HfO or HfO2), SrTiO3, SnO2, CeO2, MgO, NiO, CaO, ZnO, Y2O3, boehmite (y-AlO(OH)), Al2O3, TiO2, SiC, ZrO2, borosilicates, BaSO4, and nanoclay, or mixtures thereof. The diaphragm coating may optionally contain 0% to 15% by weight, preferably 0.1% to 10% by weight, of an additive based on the polymer, selected from thickeners, pH adjusters, anti-settling agents, surfactants, wetting agents, fillers, defoamers, and short- or long-acting adhesion promoters. The fillers mentioned herein are different from the inorganic particles mentioned above.

[0129] According to an alternative embodiment, the diaphragm does not contain a porous support. In this case, the diaphragm consists of a coating as described above and comprising the composition; it is deposited directly on the cathode or anode of the electrochemical device. The absence of a porous support allows for limitations on the manufacturing cost and size of the electrochemical device. In this case, the coating replaces the porous support. In this embodiment, the porosity of the composition is preferably 5% to 95%. The diaphragm coating of the present invention exhibits an excellent trade-off in terms of diaphragm coating application performance: good dry and wet adhesion, good resistance to electrolyte solvents, characterized by good integrity and moderate swelling.

[0130] According to another aspect of the present invention, a lithium-ion battery is provided. Preferably, the lithium-ion battery includes a positive electrode, a negative electrode, and a separator, wherein at least one of the electrodes is an electrode according to the present invention, or the separator is a separator according to the present invention. Preferably, the lithium-ion battery further comprises a lithium salt selected from the following: 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 and LiTDI, or mixtures thereof.

[0131] According to another aspect of the invention, the composition can be used to prepare conductive polymers, solid electrolytes for fuel cells, hydrophilic coatings (layers), hydrophobic coatings (layers), or UV-absorbing coatings (layers). The composition can be used as a binder for extruded multilayer structures in the form of membranes, sheets, or tubes. The composition can also be used as a coating on metals.

[0132] Example

[0133] Method for preparing polymer P2 according to the present invention

[0134] Polymer P2A

[0135] Weigh 796 g of deionized water and 5.9 g of sodium dodecyl sulfate into a 1000 ml glass reactor equipped with mechanical stirring and oil bath heating. The combined mixture is then heated to 78°C. In the first container, weigh out 33 g of 2-(methacryloyloxy)ethyl acetoacetate and 297.1 g of methyl methacrylate. In the second container, add a solution of 0.99 g of ammonium persulfate dissolved in 20 g of deionized water. In the third container, add 3.3 g of a 50% solution of sodium 2-acrylamido-2-methyl-1-propanesulfonate (AMPS). Then, introduce the persulfate solution, the sodium 2-acrylamido-2-methyl-1-propanesulfonate solution, and the 16.5 g mixture from the first container all at once.

[0136] The mixture was then boiled for 15 minutes, followed by the addition of the remaining contents from the first container over two hours at 78°C using a peristaltic pump. The pump was then rinsed with 10 g of deionized water. Subsequently, a solution consisting of 0.3 g of sodium persulfate and 25 g of deionized water was added over 1 hour at 78°C. The mixture was then boiled again at 78°C for 1 hour. A latex containing 26% dry matter was obtained, with an average median particle diameter of 43 nm.

[0137] Polymer P2B

[0138] Polymer P2B was prepared in the same manner as polymer P2A, except that sodium 2-acrylamido-2-methyl-1-propanesulfonate (AMPS) solution was not introduced.

[0139] Preparation of polymer P3A

[0140] 796 g of deionized water and 5.9 g of sodium dodecyl sulfate were weighed into a 1000 ml glass reactor equipped with mechanical stirring and oil bath heating.

[0141] The combined mixture is then heated to 78°C.

[0142] 33 g of acrylic acid and 297.1 g of methyl methacrylate were weighed out in the first container.

[0143] In the second container, 0.99 g of ammonium persulfate was dissolved in 20 g of deionized water. In the third container, 3.3 g of a 50% solution of sodium 2-acrylamido-2-methyl-1-propanesulfonate was added. The persulfate solution, the sodium 2-acrylamido-2-methyl-1-propanesulfonate solution, and 16.5 g of the mixture from the first container were then rapidly introduced in one go. The mixture was then boiled for 15 minutes, followed by the addition of the remaining contents from the first container over two hours at 78°C using a peristaltic pump. The pump was then rinsed with 10 g of deionized water. Subsequently, a solution consisting of 0.3 g of sodium persulfate and 25 g of deionized water was added over 1 hour at 78°C. The mixture was boiled again at 78°C for 1 hour. A latex containing 26.4% dry matter was obtained, with an average median particle diameter of 45 nm.

[0144] Polymer P3B

[0145] Polymer P3B was prepared in the same manner as polymer P3A, except that sodium 2-acrylamido-2-methyl-1-propanesulfonate (AMPS) solution was not introduced.

[0146] Methods for preparing mixtures

[0147] P1 is a product that meets the requirements of ASTM D-3835 method at 232°C and 100 seconds. -1 The melt viscosity of the vinylidene fluoride homopolymer was measured to be 47-53 kpoise.

[0148] P2A is a copolymer of methyl methacrylate, acetoacetoxymethyl methacrylate, and AMPS in a molar ratio of 89.5 / 10 / 0.5. P2B is a copolymer of methyl methacrylate and acetoacetoxymethyl methacrylate in a molar ratio of 90 / 10. AMPS may optionally be used as a comonomer to promote emulsion stability, if desired.

[0149] P3A is a copolymer of methyl methacrylate, AMPS, and acrylic acid in a molar ratio of 89.5 / 0.5 / 10. P3B is a copolymer of methyl methacrylate and acrylic acid in a molar ratio of 90 / 10.

[0150] P2A, P2B, P3A, and P3B latexes were freeze-dried, and then these copolymers were mixed with polymer P1, wherein the weight ratio of P1 / [P2+P3] was 90 / 10, and 92% by weight of N-methylpyrrolidone (NMP) was used as an organic solvent to form an adhesive solution. The various mixtures studied are shown in Table 1.

[0151] [Table 1]

[0152]

[0153] P2A, P2B, P3A, and P3B refer to the polymers used in the examples. The ratio refers to the weight ratio.

[0154] Preparation of slurry composition for positive electrode

[0155] 97% by weight of LiNi will be used as the positive electrode active material. 0.8 Co 0.1 Mn 0.1 O2 (NMC), 1.5 wt% carbon black C65 as a conductive material, 1.5 wt% binder solution, and an appropriate amount of N-methylpyrrolidone (NMP) as an organic solvent were mixed in a Thinky mixer. The solid concentration was then 72 wt%. Subsequently, NMP was added, resulting in a mixture that reacted within 10 seconds. -1 The viscosity at the shear rate is about 4000-6000 mPa·s, in order to prepare a dispersion for the positive electrode.

[0156] An aluminum foil with a thickness of 20 μm was prepared as a current collector.

[0157] The obtained suspension composition for the positive electrode was applied to one side of an aluminum foil, resulting in a coating weight of 22 mg / cm² after drying. 2 The coating was performed on a coating line at a coating speed of 0.2 m / min and a drying temperature of 50°C to 90°C. The positive electrode strip was then laminated by pressing to produce a product consisting of aluminum foil (current collector) and a density of 3.4 g / cm³. 3 A sheet-like positive electrode composed of layers of mixed positive electrode materials.

[0158] Methods for measuring peeling

[0159] According to standard ASTM D903, the electrode was subjected to a peel test at 25°C and 25 mm / min at 180° to evaluate the adhesion of the electrode composition coating to the metal sheet.

[0160] Lithium half-cells (CR2032 type, 20 mm in diameter) were prepared in a drying chamber at a dew point of -40°C by perforating small disks (12 mm in diameter) of the prepared electrodes, with lithium metal (12 mm in diameter) serving as the counter electrode / reference. Lithium hexafluorophosphate (LiPF6) was dissolved in a mixture of ethylene carbonate and methyl ethyl carbonate (weight ratio = 3:7) to obtain a non-aqueous electrolyte with a concentration of 1 mol / L.

[0161] The positive and negative electrodes are positioned opposite each other with a 300 μm thick microporous glass microfiber (separator) in between, and 100 μL of the non-aqueous electrolyte obtained above is injected; after the non-aqueous electrolyte has fully penetrated into the separator, the button cell is sealed, pre-charged and aged to manufacture a lithium-ion half cell.

[0162] Methods for measuring capacity retention

[0163] After initial charge and discharge cycles (formation stage) at a low current of 0.1C, each half-cell prepared as described above was subjected to constant current cycling. That is, the charge / discharge cycle was performed by charging at a constant voltage equivalent to 0.1C (hereinafter referred to as CC / CV charging) (cutoff value 0.05C) to 4.2V, and then discharging at equivalent currents of 0.2C, 0.3C, 0.5C, 1C to 2C to 3V, where 1C represents the current value discharging the battery's reference capacity in 1 hour, and for example, 0.2C represents its current value in 1 / 5 hour. The ratio of the 2C discharge capacity to the 0.1C discharge capacity is calculated as follows: Discharge characteristic 2C / 0.1C (%) (2C discharge capacity) ÷ (0.1C discharge capacity) × 100 = 2C / 0.1C. The results are given in Table 2.

[0164] [Table 2]

[0165]

[0166] KF W#9700 (Kureha Corporation) is a copolymer of vinylidene fluoride and a monomer containing acid groups.

[0167] As can be seen in Table 2, the electrode composition according to the invention, which includes polymer P2, makes it possible to obtain electrodes that exhibit both good retention capacity and very good adhesion.

Claims

1. A composition comprising a fluoropolymer P1 and a copolymer P2, wherein the fluoropolymer P1 comprises monomer units generated from a fluorinated monomer M1a, and the copolymer P2 comprises monomer units generated from formula (Ia)R 1 R 2 C=C(R 3 )C(O)R or (Ib)R 1 R 2 C=C(R 3 The monomer unit generated by R” and the monomer unit generated by monomer M2b of formula (II): in: Substituent R 1 R 2 and R 3 Each of the elements is independently selected from H, C1-C5 alkyl groups, and NH2; R” is selected from C6-C 12 Aryl and CN; R is selected from –NHC(CH3)2CH2C(O)CH3 and -OR', where R' is selected from 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. ’’’ or -C(O)OR ”’ A group, or a five- or ten-membered heterocyclic substitution, wherein the five- or ten-membered heterocyclic contains at least one nitrogen atom in its ring chain; R ’’’ Selected from C1-C6 alkyl and C6-C groups optionally substituted with one or more -OH, -CO2H, -SO3H or -PO3H groups. 12 Aryl; R 4 R 5 R 6 and R 9 They are independently selected from H and C1-C5 alkyl groups; R 7 and R 8 They are selected independently of each other and for each unit n from H and C1-C5 alkyl groups; X is selected from C1-C 18 Alkyl and C4-C 18 cycloalkyl; n is an integer from 1 to 10, preferably from 1 to 5; in particular, n is 1.

2. The composition according to the preceding claim, characterized in that, Substituent R 4 R 5 R 6 and R 9 They are independently selected from H and C1-C3 alkyl groups, and R 7 and R 8 They are selected independently of each other and for each unit n independently from H and C1-C3 alkyl groups.

3. The composition according to any one of the preceding claims, characterized in that, Substituent R 1 R 2 and R 3 Independently selected from: H and C1-C3 alkyl; R is -OR', where R' is selected from H and C1-C3 alkyl. 10 Alkyl, the C1-C 10 Alkyl groups are optionally surrounded by one or more -OH, -CO2H, -SO3H, -PO3H, or -OC(O)R. ”’ or -C(O)OR ”’ Group substitution, wherein R ”’ Selected from C1-C6 alkyl and C6-C groups optionally substituted with one or more -OH, -CO2H, -SO3H or -PO3H groups. 12 Aryl.

4. The composition according to any one of the preceding claims, characterized in that, The substituent X is selected from C1-C1. 10 Alkyl and C4-C 10 Cycloalkyl.

5. The composition according to any one of the preceding claims, characterized in that, The composition further comprises copolymer P3, said copolymer P3 comprising at least two of formula (I)R 1 R 2 C=C(R 3 The monomer units generated from monomers M3a and M3b of )C(O)R, wherein the substituent R 1 R 2 and R 3 Independently selected from H and C1-C5 alkyl groups; R is selected from -NHC(CH3)2CH2C(O)CH3 and -OR', wherein R' is selected from H and C1-C5 alkyl groups. 18 Alkyl, the C1-C 18 Alkyl groups are optionally surrounded by one or more -OH, -CO2H, -SO3H, -PO3H, or -OC(O)R. ”’ or -C(O)OR ”’ A group, or a five- or ten-membered heterocyclic substitution, wherein the five- or ten-membered heterocyclic contains at least one nitrogen atom in its ring chain; wherein R ”’ Selected from C1-C6 alkyl and C6-C groups optionally substituted with one or more -OH, -CO2H, -SO3H or -PO3H groups. 12 Aryl.

6. The composition according to any one of the preceding claims, characterized in that, The fluorinated monomer M1a is selected from the following: 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); monomers of the formula CF2=CFOCF2CF(CF3)OCF2CF2X, wherein X is SO2F, CO2H, CH2OH, CH2OCN, or CH2OPO3H; monomers of the formula CF2=CFOCF2CF2SO2F; and 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 The value of 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; trifluoropropylene, tetrafluoropropylene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropylene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropylene and 2-trifluoromethyl-3,3,3-trifluoro-1-propylene or mixtures thereof.

7. The composition according to any one of the preceding claims, characterized in that, The fluorinated monomer M1a is vinylidene fluoride, and optionally the polymer P1 further comprises monomer units generated from monomer M1b selected from: vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, hexafluoropropylene, perfluoro(alkyl vinyl) ethers, such as perfluoro(methyl vinyl) ether, perfluoro(ethyl vinyl) ether and perfluoro(propyl 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 has a value of 1, 2, 3 or 4, Equation R 2 The monomer of OCF=CH2, where R 2 It is F(CF2) p And p is 1, 2, 3 or 4, trifluoropropylene, tetrafluoropropylene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropylene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropylene and 2-trifluoromethyl-3,3,3-trifluoro-1-propylene or a mixture thereof.

8. The composition according to any one of the preceding claims, characterized in that, The fluoropolymer P1 has the properties according to ASTM D-3835 method at 232°C and 100 seconds. -1 The melt viscosity measured below is greater than 1000 Pa·s.

9. The composition according to any one of the preceding claims, characterized in that, The copolymer P2 has a content greater than or equal to 1000 g·mol⁻¹ -1 Number average molecular weight.

10. The composition according to any one of the preceding claims, characterized in that, The weight ratio of P1 / P2 is 50 / 50 to 99 / 1, preferably 70 / 30 to 95 / 5.

11. An adhesive for electrodes comprising the composition according to any one of the preceding claims.

12. An electrode composition comprising a binder, an active material, and optionally a conductive agent, an additive, or a mixture thereof as described in the preceding claim.

13. The electrode composition according to the preceding claim, characterized in that, The electrode composition comprises a conductive agent composed of one or more materials selected from the group consisting of carbon black, graphite, carbon fiber, carbon nanotubes, carbon nanofibers, metal powders such as SUS powder and aluminum powder, and mixtures thereof.

14. The electrode composition according to any one of claims 12 and 13, wherein the active material is selected from: LiCoO2, Li(Ni,Co,Al)O2, Li (1+x) Ni a Mn b Co c O2 (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, 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 x and y independently represent real numbers between 0 and 2, and lithium metal phosphates with a composition represented by LiMPO4, where M represents Fe, Mn, Co, or Ni.

15. The electrode composition according to any one of claims 12 and 13, wherein the active material is selected from: lithium alloys, lithium metal, metal oxides, carbon materials such as graphite or hard carbon, silicon, silicone, silicon alloys, and Li4Ti5O. 12 .

16. An electrode comprising a current collector and a layer composed of the electrode composition of any one of claims 12 to 15; preferably, the layer is in contact with the current collector.

17. A coating for a separator in a lithium-ion battery, comprising the composition according to any one of claims 1 to 10.

18. A separator for a Li-ion battery, comprising a coating as described in the preceding claims and inorganic particles optionally selected from: BaTiO3, Pb(Zr,Ti)O3, Pb 1-x La x Zr y O3(0 <x<1,0<y<1)、PbMg 1 / 3 Nb 2 / 3 O3, PbTiO3, hafnium dioxide (HfO, HfO2), SrTiO3, SnO2, CeO2, MgO, NiO, CaO, ZnO, Y2O3, boehmite (y-AlO(OH)), Al2O3, TiO2, SiC, ZrO2, borosilicates, BaSO4 and nanoclay, or mixtures thereof.

19. A lithium-ion battery comprising a positive electrode, a negative electrode, and a separator, characterized in that, At least one of these electrodes is an electrode as claimed in claim 16 or the diaphragm is a diaphragm as claimed in claim 18.

20. Use of the composition according to any one of claims 1 to 8 for the preparation of conductive polymers, solid electrolytes for fuel cells, hydrophilic coatings, hydrophobic coatings or UV-absorbing coatings; or use as an adhesive for extruded multilayer structures in the form of membranes, sheets or tubes; or use of the copolymer as a coating on metals.

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