Solid electrolyte and its preparation

Abstract

The present invention relates to compositions comprising particles of a fluorinated polymer and solid inorganic particles characterized in that said solid inorganic particles have a Young's modulus between 1 and 100 GPa and in that said fluorinated polymer has a molten viscosity of less than 45 kPoise measured at 230°C at a shear rate of 100 s-1 according to ASTM D3835.

Description

Title of the invention: Solid electrolyte and its preparation technical field

[0001] The present invention relates generally to the field of electrical energy storage in rechargeable lithium-based secondary batteries. More specifically, the invention relates to a composition for the preparation of an all-solid electrolyte. Technological background

[0002] Lithium-ion batteries typically use liquid electrolytes composed of solvent(s), lithium salt(s), and additive(s). These electrolytes have good ionic conductivity but are susceptible to leakage or ignition if the battery is damaged. The use of solid electrolytes is a solution to overcome these difficulties.

[0003] To manufacture these all-solid electrolytes, inorganic materials such as ceramics are used. Two main families are primarily studied: oxides and sulfides. The latter have the unique characteristic of being very good ionic conductors of the Li+ cation. However, their main drawback is their very high reactivity to humidity, making their processing complex. Oxides also have low ductility, requiring the use of hot sintering methods for their processing, which are poorly suited to battery electrode applications because they result in films on the order of 80 to 100 µm thick. For this reason, the sulfide family is favored in recent research because these materials exhibit greater ductility.

[0004] Among sulfides, Li6PS5Cl type materials are particularly used. These are used in the presence of a binder, which can be polyethylene oxide (PEO). The preparation of a solid electrolyte composed of PEO, LiTFSI, and Li6PS5Cl is known, in particular, from Yi et al., Journal of Energy Chemistry, 2021, 58, 17-24.

[0005] One of the challenges related to the commercialization of all-solid-state batteries is the long-term stability of the solid-to-solid interfaces. The interface is responsible for the electronic and ionic transfer that governs the proper functioning of the battery. Unfortunately, the solid sulfur electrolyte LPSC1 is chemically very reactive to oxygenated compounds, leading to reactions that are detrimental to the interfaces. The PS43 crystal motif, which ensures the conduction of lithium ions, can evolve into PS4 XOX3 upon contact, for example, with active materials or polymers (PEO). Polyethylene oxide exhibits some reactivity with LPSC1 particles; therefore, it is necessary to reduce the number of chain terminations. Polymer electrolytes or PEO-based composite electrolytes also have high operating temperatures (60-80°C), which is unsuitable for everyday use at room temperature. Furthermore, the addition of lithium salt is essential to this type of polymer to improve ionic conductivity.

[0006] There is therefore a need for new solid electrolytes capable of stabilizing sulfides while maintaining high ionic conductivity. The present invention makes it possible to solve all or part of the above drawbacks. Summary of the invention

[0007] According to a first aspect, the present invention provides a dry composition comprising particles of a fluorinated polymer and solid inorganic particles, characterized in that said solid inorganic particles have a Young's modulus between 1 and 100 GPa and in that said fluorinated polymer has a melt viscosity of less than 45 kPoise measured at 230°C at a shear rate of 100 s⁻¹ according to ASTM D3835. The Young's modulus of said solid inorganic particles is determined by nanoindentation according to ISO 14577. The model used for calculating the Young's modulus is that developed by Oliver-Pharr, described in Oliver et al., J. Mater. Res., 1992, Vol. 7, No. 6, 1564-1583.

[0008] The present invention allows for the preparation of an electrolyte by dry process, without the addition of solvent, thus avoiding the difficulties of dispersion and sedimentation of the various constituents over time. The fluorinated polymer used in this application reacts little or not at all with solid inorganic particles, but also improves ionic conductivity compared to other higher-mass fluorinated polymers. Furthermore, the fluorinated polymer improves the mechanical and passive strength of the surface, thereby extending the battery's lifespan.

[0009] Furthermore, the preparation of a solid electrolyte from the dry composition according to the present invention is facilitated by the absence of solvent, reducing the economic cost of its preparation and avoiding the environmental problems associated with solvent recycling.

[0010] According to a preferred embodiment, said solid inorganic particles contain at least one sulfur atom and at least one phosphorus atom and optionally at least one element from the halogen column.

[0011] According to a preferred embodiment, said solid inorganic particles are selected from the group consisting of: - lithium tin sulfide phosphorus ("Isps") such as LiioSnP2Si2; - Lithium sulfide phosphorus (“Ips”) of formula (Li2S)x(P2S5)y, wherein x+ y=l and 0 < x < 1, Li7P3Sn, Li7PS6, Li4P2S6, LiQ>6P3Si2 and Li3PS4; - Doped LPS such as Li2CuPS4, Lii+2xZni_xPS4, in which 0 < x < 1, Li333Mg 0.33P2S6, and Li4 3xScxP2S6, in which 0 < x < 1; - Lithium sulfide phosphorus oxygen ("LPSO") of formula LixPySzO, in which 0.33 < x < 0.67, 0.07 < y < 0.2, 0.4 < z < 0.55, 0 < w < 0.15; - Lithium sulfide phosphorus ("LXPS") with x Si, Ge, Sn, As, Al, such as Liio GeP2S[2 or Lii0SiP2Si2; - Lithium sulfide phosphorus oxygen ("LXPSO") with x Si, Ge, Sn, As, Al; - Lithium sulfide silica (“LSS”) such as Li2S-P2S5-SiS2, Li2S-P2S5-SiS2-LiCl, Li2S-SiS2-P2S5, Li2S-SiS2-P2S5-LiI, Lh,54Si1.74P1.44S11.7Cl0.3; Li4PS4Cl, Li15P3S16Cl3, Li7P2S8Cl and Li7P2S8I; - Materials of formula Li6PS5Y in which Y is Cl, Br or I such that; Li6.x PS5 XYUx, in which 0 < x < 0.5; preferably Li6PS5Cl; - and mixtures thereof.

[0012] According to a preferred embodiment, said fluorinated polymer comprises repeating units derived from vinylidene fluoride and optionally repeating units of a monomer Ml selected from the group consisting of vinyl fluoride; trifluoroethylene; chlorotrifluoroethylene; 1,2-difluoroethylene; tetrafluoroethylene; hexafluoropropylene; perfluoro(alkyl vinyl) ethers such as perfluoro(methylvinyl) ether (PMVE), perfluoro(ethyl vinyl) ether (PEVE) and perfluoro(propylvinyl) ether (PPVE); perfluoro(1,3-dioxole); perfluoro(2,2-dimethyl-1,3-dioxole) (PDD); the product of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H; the product of formula CF2=CFOCF2CF2SO2F; the product of formula F(CF2)nCH2OCF=CF2 in which n is 1, 2, 3, 4 or 5; the product of formula R1CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4;the product of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4; perfluorobutyl ethylene (PFBE); 3,3,3-trifluoropropene and 2-trifluoromethyl-3,3,3-trifluoro-l-propene or a mixture thereof.

[0013] According to a preferred embodiment, said fluorinated polymer is a homopolymer of vinylidene fluoride or a polymer comprising repeating units from vinylidene fluoride and repeating units from a monomer Ml selected from the group consisting of trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, chlorofluoroethylene, tetrafluoroethylene and hexafluoropropylene or a mixture thereof.

[0014] According to a preferred embodiment, said fluorinated polymer is a homopolymer of vinylidene fluoride or a polymer selected from the group consisting of:

[0015] - the copolymer comprising repeating units derived from vinylidene fluoride and repeating units derived from hexafluoropropylene,

[0016] - the copolymer comprising repeating units derived from vinylidene fluoride and repeating units derived from trifluoroethylene,

[0017] - the copolymer comprising repeating units derived from vinylidene fluoride and repeating units derived from chlorotrifluoroethylene,

[0018] - the copolymer of repeating units derived from vinylidene fluoride and units repetitive effects derived from tetrafluoroethylene, and

[0019] - a fluorinated terpolymer selected from: the terpolymer comprising units repeating units derived from vinylidene fluoride, repeating units derived from trifluoroethylene and repeating units derived from chlorofluoroethylene, the terpolymer comprising repeating units derived from vinylidene fluoride, repeating units derived from trifluoroethylene and repeating units derived from chlorotrifluoroethylene, the terpolymer comprising repeating units derived from vinylidene fluoride, repeating units derived from trifluoroethylene and repeating units derived from hexafluoropropylene, the terpolymer comprising repeating units derived from vinylidene fluoride, repeating units derived from tetrafluoroethylene and repeating units derived from chlorofluoroethylene, the terpolymer comprising repeating units derived from vinylidene fluoride, repeating units derived from tetrafluoroethylene and repeating units derived from chlorotrifluoroethylene,and the terpolymer comprising repeating units derived from vinylidene fluoride, repeating units derived from tetrafluoroethylene and repeating units derived from hexafluoropropylene,

[0020] or a mixture of the aforementioned copolymers or terpolymers.

[0021] According to a preferred embodiment, said fluorinated polymer comprises a mass content of repeating units from vinylidene fluoride of at least 50% by weight on the basis of the total weight of said fluorinated polymer.

[0022] According to a preferred embodiment, said composition contains less than 0.1% by weight of lithium salt on the basis of the total weight of said composition, said lithium salt being different from said solid inorganic particles, preferably said composition is devoid of lithium salt.

[0023] According to another aspect, the present invention provides a solid composite electrolyte comprising, preferably consisting of, said dry composition according to the present invention.

[0024] According to another aspect, the present invention provides an all-solid-state battery comprising said solid composite electrolyte according to the present invention.

[0025] According to another aspect, the present invention provides a composition comprising particles of a fluorinated polymer, an organic solvent and solid inorganic particles characterized in that: - said solid inorganic particles have a Young's modulus between 1 and 100 GPa; - said fluorinated polymer is a homopolymer having a melt viscosity of less than 45 kPoise measured at 230°C at a shear rate of 100 s 1 according to ASTM D3835; - said organic solvent is an aprotic solvent and has a donor number greater than or equal to 5 kcal / mol; and - said composition comprises less than 0.1% by weight of lithium salt on the basis of the total weight of said composition, said lithium salt being different from said solid inorganic particles, preferably said composition is free of lithium salt.

[0026] This composition makes it possible to improve the ionic conductivity of an electrolyte prepared in a solvent medium. Thanks to the use of the fluorinated polymer according to the invention, it is possible to provide a less toxic and less expensive solid electrolyte due to the low lithium salt content or its absence. The fluorinated polymer used in this application does not react with solid inorganic particles but also improves ionic conductivity compared to other higher-mass fluorinated polymers.

[0027] According to a preferred embodiment, said inorganic particles are as defined in this application.

[0028] According to a preferred embodiment, said fluorinated polymer is a homopolymer derived from a monomer Ml selected from the group consisting of vinyl fluoride; vinylidene fluoride, trifluoroethylene; chlorotrifluoroethylene; 1,2-difluoroethylene and tetrafluoroethylene; preferably said fluorinated polymer is a homopolymer derived from vinylidene fluoride.

[0029] According to another aspect, the present invention provides a solid composite electrolyte comprising, preferably consisting of, said composition according to the present invention.

[0030] According to another aspect, the present invention provides an all-solid-state battery comprising said solid composite electrolyte according to the present invention. Detailed description of the invention Composition

[0031] The present invention provides a solid electrolyte having a good compromise between mechanical and electrochemical properties. This solid electrolyte can be obtained or prepared from a dry composition or a solvent-based composition, i.e., one comprising an organic solvent. In both cases, very good properties are obtained through the specific use of a fluorinated polymer instead of polyethylene oxide (PEO); the dry composition also allows for the avoidance of This solvent thus offers an eco-responsible solution. The advantage of fluorinated polymers, particularly PVDF, lies in their less reactive chemistry with solid inorganic particles containing sulfur, due to the absence of oxygen in their structure.

[0032] According to a first aspect of the present invention, a dry composition is provided. Said dry composition comprises solid inorganic particles and particles of a fluorinated polymer. Preferably, said solid inorganic particles have a Young's modulus between 1 and 100 GPa. The said solid inorganic particles may have a Young's modulus between 2 and 95 GPa, advantageously between 3 and 90 GPa, preferably between 4 and 85 GPa, more preferably between 5 and 80 GPa, in particular between 10 and 75 GPa, more particularly between 10 and 70 GPa, preferably between 10 and 65 GPa, advantageously preferred between 10 and 60 GPa, preferentially preferred between 10 and 55 GPa, more preferably preferred between 10 and 50 GPa, particularly preferred between 15 and 45 GPa, more particularly preferred between 20 and 40 GPa.

[0033] Said fluorinated polymer may have a molten viscosity of less than 45 kPoise, advantageously less than 44 kPoise, preferably less than 43 kPoise, more preferably less than 42 kPoise, in particular less than 41 kPoise measured at 230°C at a shear rate of 100 s 1 according to ASTM D3835.

[0034] Preferably, said fluorinated polymer has a melt viscosity of less than 40 kPoise measured at 230°C at a shear rate of 100 s⁻¹ according to ASTM D3835. Said fluorinated polymer may have a melt viscosity of less than 39 kPoise, advantageously less than 38 kPoise, preferably less than 37 kPoise, more preferably less than 36 kPoise, in particular less than 35 kPoise, more particularly less than 34 kPoise, preferably less than 33 kPoise, advantageously less than 32 kPoise, preferably less than 31 kPoise, particularly less than 30 kPoise measured at 230°C at a shear rate of 100 s⁻¹ according to ASTM D3835.Said fluorinated polymer preferably has a molten viscosity greater than 1 kPoise, advantageously greater than 2 kPoise, preferably greater than 3 kPoise, more preferably greater than 4 kPoise, in particular greater than 5 kPoise measured at 230°C at a shear rate of 100 s⁻¹ according to ASTM D3835.

[0035] The use of this fluorinated polymer with a specific molecular weight allows for better dispersion of the polymer within the solid electrolyte, particularly during the mixing of the two powders. This improved dispersion, coupled with the favorable mechanical properties of the polymers, also helps to limit the penetration of dendrites during cycling and helps to limit mechanical fracturing that can occur during cycling.

[0036] This combination of the two components allows densification at room temperature with a relatively high pressure.

[0037] In said dry composition, the mass content of fluorinated polymer is preferably between 1 and 15%, advantageously between 2 and 14%, preferably between 3 and 13%, more preferably between 3 and 12%, in particular between 3 and 11%, and more particularly between 3 and 10% based on the total weight of said dry composition. A mass content of fluorinated polymer between 3 and 10% based on the total weight of said dry composition is particularly preferred because it has been observed that above 10% the ionic conductivity becomes too low for power applications, given the insulating nature of said fluorinated polymer. This is particularly noticeable above 15% by weight of fluorinated polymer in the dry composition. It has also been observed that below 3% by weight of fluorinated polymer, the addition of polymer does not help to improve the mechanical strength of the composition during cycling. This is particularly noticeable below 1% by weight.

[0038] Preferably, said dry composition contains less than 0.1% by weight of lithium salt in the polymer matrix based on the total weight of the composition, advantageously less than 0.05% by weight, preferably less than 0.01% by weight, in particular, less than 0.005% by weight, more particularly less than 0.001% by weight of lithium salt based on the total weight of the composition. In a preferred embodiment, said dry composition is free of lithium salt. Said lithium salt is distinct from solid inorganic particles that also contain lithium. The lithium salt mentioned here is a lithium salt commonly used in liquid electrolyte compositions such as, for example, LiCF3SO3, LiPF6, LiClO4, LiBF4, LiB(C2O4)2, LiN(SO2F)2, LiN(SO2CF3)2, LiN(SO2C2F3)2, LiN(SO2 CF2CF3)2, LiN(SO2F)(SO2CF3), LiN(SO2F)(SO2CF2CF3), LiN(SO2CF3)(SO2CF2CF3), LiAsF6, LiBF2C2O4, LiNO3, LiPF3(CF2CF3)3, LiTDI.The lithium salt mentioned herein does not have a Young's modulus between 1 and 100 GPa as described in this application for the said solid inorganic particles.

[0039] According to another aspect of the present invention, a composition comprising particles of a fluorinated polymer, an organic solvent, and solid inorganic particles is provided. In this composition, said solid inorganic particles have a Young's modulus of between 1 and 100 GPa. Said solid inorganic particles may have a Young's modulus of between 2 and 95 GPa, advantageously between 3 and 90 GPa, preferably between 4 and 85 GPa. more preferentially between 5 and 80 GPa, in particular between 10 and 75 GPa, more particularly between 10 and 70 GPa, preferentially between 10 and 65 GPa, advantageously preferred between 10 and 60 GPa, preferentially preferred between 10 and 55 GPa, more preferentially preferred between 10 and 50 GPa, particularly preferred between 15 and 45 GPa, more particularly preferred between 20 and 40 GPa.

[0040] In this composition, said fluorinated polymer may have a melt viscosity of less than 45 kPoise, advantageously less than 44 kPoise, preferably less than 43 kPoise, more preferably less than 42 kPoise, in particular less than 41 kPoise measured at 230°C at a shear rate of 100 s⁻¹ according to ASTM D3835. Preferably, in this composition, said fluorinated polymer may have a melt viscosity of less than 40 kPoise measured at 230°C at a shear rate of 100 s⁻¹ according to ASTM D3835.The said fluorinated polymer may have a molten viscosity of less than 39 kPoise, advantageously less than 38 kPoise, preferably less than 37 kPoise, more preferably less than 36 kPoise, in particular less than 35 kPoise, more particularly less than 34 kPoise, preferably less than 33 kPoise, advantageously preferred less than 32 kPoise, preferably preferred less than 31 kPoise, particularly preferred less than 30 kPoise measured at 230°C at a shear rate of 100 s⁻¹ according to ASTM D3835. Said fluorinated polymer preferably has a molten viscosity greater than 1 kPoise, advantageously greater than 2 kPoise, preferably greater than 3 kPoise, more preferably greater than 4 kPoise, in particular greater than 5 kPoise measured at 230°C at a shear rate of 100 s⁻¹ according to ASTM D3835.

[0041] The composition according to this aspect of the present invention comprises an organic solvent. This solvent is preferably an aprotic solvent and has a donor number greater than or equal to 5 kcal / mol. The organic solvent is also detailed below in this application.

[0042] In this aspect of the present invention, said composition contains less than 0.1% by weight of lithium salt based on the total weight of the composition, advantageously less than 0.05% by weight, preferably less than 0.01% by weight, in particular, less than 0.005% by weight, more particularly less than 0.001% by weight of lithium salt based on the total weight of the composition. In a preferred embodiment, said composition is free of lithium salt. Said lithium salt is different from solid inorganic particles that also contain lithium. Said lithium salt referred to herein is a lithium salt commonly used in compositions of liquid electrolytes such as, for example, LiCF3SO3, LiPF6, LiC1O4, LiBF4, LiB(C2O4)2, LiN(SO2F)2, LiN(SO2CF3)2, LiN(SO2C2F3)2, LiN(SO2CF2CF3)2, LiN(SO2F)(SO2CF3), LiN(SO2F)(SO2CF2CF3), LiN(SO2CF3)(SO2CF2CF3), LiAsF6, LiBF2C2O4, LiNO3, LiPF3(CF2CF3)3, LiTDI. The lithium salt mentioned herein has a Young's modulus between 1 and 100 GPa as described in this application for the said solid inorganic particles.

[0043] Said fluorinated polymer, said solid inorganic particles and said solvent mentioned in the compositions according to the present invention are detailed below. Solid inorganic particles

[0044] Said inorganic particles preferably contain at least one sulfur atom and at least one phosphorus atom. These solid inorganic particles may be amorphous, semi-crystalline, or crystalline. Preferably, said solid inorganic particles are crystalline or semi-crystalline.

[0045] Preferably, said solid inorganic particles are selected from the group consisting of: - lithium tin sulfide phosphorus ("Isps") such as LiiOSnP2Si2; - Lithium sulfide phosphorus (“Ips”) of formula (Li2S)x(P2S5)y, wherein x+ y=l and 0 < x < 1, Li7P3Sn, Li7PS6, Li4P2S6, LiQ.6P3Si2 and Li3PS4; - Doped Lps such as Li2CuPS4, Lii+2xZni_xPS4, in which 0 < x < 1, Li3 33Mg 0.33P2S6, and Li4 3xScxP2S6, in which 0 < x < 1; - Lithium sulfide phosphorus oxygen ("LPSO") of formula LixPySzO, in which 0.33 < x < 0.67, 0.07 < y < 0.2, 0.4 < z < 0.55, 0 < w < 0.15; - Lithium sulfide phosphorus ("Ixps") with x Si, Ge, Sn, As, Al, such as LiiO GeP2Si2 or LiioSiP2Si2; - Lithium sulfide phosphorus oxygen ("LXPSO") with x Si, Ge, Sn, As, Al; - Lithium sulfide silica (“LSS”) such as Li2SiS3, Li2S-P2S5-SiS2, Li2S-P2S5-SiS 2-LiCl, Li2S-SiS2-P2S5, Li2S-SiS2-P2S5-LiI, Li2S-SiS2-LiI, Li2S-SiS2, Li9 54Si174P i.44Si 17Clo.3, and Li2S-SiS2-Al2S3; - Lithium boron sulfide such as Li3BS3 or L2S-B2S3-Li; - Lithium tin sulfide and lithium arsenite such as Li₂O₃, Li₄S₂S₄, Li₃O₈S₃ 0.833^^0. iooS4, Li3AsS4-Li4SnS4, Li3AsS4; And Li4PS4Cl, Li15P3S16Cl3, Li7P2S8Cl, and Li7P2S8I; - Materials of formula Li6PS5Y in which Y is Cl, Br or I; Li6 XPS5 xY [+x , in which 0 < x < 0.5 ; preferably Li6PS5Cl; Li2S-GeS2-ZnS, Li3SbS4, Na3PS4, Na10SnP12Si2, and NaHSn2PSi2; - and mixtures thereof.

[0046] Preferably, said inorganic material may be selected from the group consisting of materials of formula Li6PS5Y in which Y is Cl, Br or I, Li6 XPS5 x Y1+x in which 0 < x < 0.5, Li2S-P2S5, Li2S-P2S3, Li2S-P2S3-P2S5, Li2S-SiS2, Li1-Li2 S-SiS2, Li1-Li2S-P2S5, Li1-Li2S-P2O5, Li1-Li3PO4-P2S5, Li1-Li2S-SiS2-P2S5, Li2S-SiS2-Li4SiO4, Li2S-SiS2-Li3PO4, Li3PS4-Li4GeS4, Li34Po.6SiO4.4S4, Li325Po.25Geo.76S4, Li4xGeXPXS4 and a mixture of these.

[0047] In particular, said inorganic material may be selected from the group consisting of materials of formula Li6PS5Y in which Y is Cl, Br or I, Li6 XPS5 XY i+x in which 0 < x < 0.5, Li2S-P2S5 and a mixture of these. Fluorinated polymer

[0048] According to a preferred embodiment, said fluorinated polymer comprises in its chain at least repeating units of a fluorinated monomer selected from compounds containing a vinyl group capable of opening to polymerize and which contains, directly attached to this vinyl group, at least one fluorine atom, a fluoroalkyl group or a fluoroalkoxy group.

[0049] Preferably, said fluorinated polymer comprises repeating units from a monomer selected from the group consisting of vinyl fluoride; vinylidene fluoride (VDF); trifluoroethylene (TrFE); chlorotrifluoroethylene (CTFE); 1,2-difluoroethylene; tetrafluoroethylene (TFE); hexafluoropropylene (HFP); perfluoro(alkyl vinyl) ethers such as perfluoro(methyl vinyl) ether (PMVE), perfluoro(ethyl vinyl) ether (PEVE) and perfluoro(propyl vinyl) ether (PPVE); perfluoro(1,3-dioxole); perfluoro(2,2-dimethyl-1,3-dioxole) (PDD); the product of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H; the product of formula CF2=CFOCF2CF2SO2F; the product of formula F(CF2)nCH2OCF=CF2 in which n is 1, 2, 3, 4 or 5; the product of formula R1CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4; the product of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4; perfluorobutylethylene (PFBE);Trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene, and 2-trifluoromethyl-3,3,3-trifluoro-1-propene, or a mixture thereof. Examples of trifluoropropenes include 3,3,3-trifluoropropene. Examples of tetrafluoropropenes include 2,3,3,3-tetrafluoropropene and 1,3,3,3-tetrafluoropropene. Examples of pentafluoropropenes include 1,1,3,3,3-pentafluoropropene and 1,2,3,3,3-pentafluoropropene. Chlorofluoroethylene can refer to either 1-chloro-1-fluoroethylene or 1-chloro-2-fluoroethylene. The isomer; 1-chloro-l-fluoroethylene is preferred. Chlorotrifluoropropene is preferably 1-chloro-3,3,3-trifluoropropene or 2-chloro-3,3,3-trifluoropropene.

[0050] In particular, said fluorinated polymer comprises at least repeating units derived from a monomer being vinylidene fluoride. The fluorinated polymer may be a homopolymer or a copolymer of vinylidene fluoride.

[0051] According to a particular embodiment, the fluorinated polymer is a vinylidene fluoride homopolymer.

[0052] According to another particular embodiment, the fluorinated polymer is a polymer comprising repeating units from a monomer being vinylidene fluoride and repeating units from a fluorinated monomer Ml copolymerizable with vinylidene fluoride.

[0053] According to one embodiment, said fluorinated polymer comprises repeating units from a vinylidene fluoride monomer and repeating units from a fluorinated monomer Ml selected from the group consisting of vinyl fluoride; trifluoroethylene (TrFE); chlorotrifluoroethylene (CTFE); 1,2-difluoroethylene; tetrafluoroethylene (TFE); hexafluoropropylene (HFP); perfluoro(alkyl vinyl) ethers such as perfluoro(methyl vinyl) ether (PMVE), perfluoro(ethyl vinyl) ether (PEVE) and perfluoro(propyl vinyl) ether (PPVE); perfluoro(1,3-dioxole); perfluoro(2,2-dimethyl-1,3-dioxole) (PDD); the product of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H; the product of formula CF2=CFOCF2CF2SO2F; the product of formula F(CF2)nCH2OCF=CF2 in which n is 1, 2, 3, 4 or 5; the product of formula R1CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4;the product of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4; perfluorobutyl ethylene (PFBE); trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene and 2-trifluoromethyl-3,3,3-trifluoro-1-propene or a mixture thereof. Preferably, the fluorinated polymer comprises repeating units from a vinylidene fluoride monomer and repeating units from a fluorinated monomer M1 selected from the group consisting of vinyl fluoride; trifluoroethylene; chlorotrifluoroethylene; 1,2-difluoroethylene, tetrafluoroethylene; hexafluoropropylene; perfluoro(alkyl vinyl)ethers such as perfluoro(methyl vinyl)ether, perfluoro(ethyl vinyl)ether or perfluoro(propyl vinyl)ether; perfluoro(l,3-dioxole); perfluoro(2,2-dimethyl-l,3-dioxole);the product of the formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H; the product of the formula CF2=CFOCF2CF2SO2F; the product of the formula F(CF2)nCH2OCF=CF2 in which n is 1, 2, 3, 4 or 5; the ; The product of formula R'CH2OCF=CF2 in which R' is hydrogen or F(CF2)z and z is 1, 2, 3, or 4; the product of formula R”OCF=CH2 in which R” is F(CF2)z and z is 1, 2, 3, or 4; trifluoropropene, tetrafluoropropene, hexafluoroisobutylene, perfluorobutylethylene, pentafluoropropene, bromotrifluoroethylene, chlorofluoroethylene, chlorotrifluoropropene, or 2-trifluoromethyl-3,3,3-trifluoro-1-propene, or a mixture thereof. In particular, the fluorinated polymer comprises repeating units from a vinylidene fluoride monomer and repeating units from a fluorinated monomer M1 selected from the group consisting of trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, tetrafluoroethylene, and hexafluoropropylene, or a mixture thereof.The polymer said may be, for example, a copolymer of vinylidene fluoride and hexafluoropropene, a copolymer of vinylidene fluoride and trifluoroethylene, a copolymer of vinylidene fluoride and tetrafluoroethylene, a copolymer of vinylidene fluoride and chlorotrifluoroethylene, a terpolymer of vinylidene fluoride, chlorotrifluoroethylene and tetrafluoroethylene, a terpolymer of vinylidene fluoride, chlorotrifluoroethylene and trifluoroethylene, a terpolymer of vinylidene fluoride, trifluoroethylene and hexafluoropropene, a terpolymer of vinylidene fluoride, tetrafluoroethylene and 1,1-chlorofluoroethylene or a terpolymer of vinylidene fluoride, hexafluoropropene and tetrafluoroethylene.

[0054] Said fluorinated polymer may be a poly(vinylidene fluoride-hexafluoropropylene) or poly(vinylidene fluoride-chlorotrifluoroethylene) copolymer. In this case, said fluorinated polymer may preferably have a vinylidene fluoride repeating unit content of at least 50% by weight based on the total weight of said fluorinated polymer, advantageously at least 60% by weight, preferably at least 70% by weight, more preferably at least 80% by weight, and in particular at least 85% by weight based on the total weight of said fluorinated polymer. Preferably, said fluorinated polymer may have a vinylidene fluoride repeating unit content by weight of between 60% and 99.5% and a chlorotrifluoroethylene or hexafluoropropylene repeating unit content by weight of between 0.5% and 40% based on the total weight of said fluorinated polymer.In particular, said fluorinated polymer may preferably have a weight content of vinylidene fluoride repeating units of between 60% and 99.5%, advantageously between 65% and 99%, preferably between 70% and 98%, particularly between 75% and 97%, more particularly between 80% and 96%, preferably between 85% and 95%; and of 0.5% and 40% by weight of chlorotrifluoroethylene or hexafluoropropylene repeating units, advantageously between 1% and 35%, preferably between 2% and 30%, particularly between 3% and 25%, more particularly between 4% and 20%, preferably between 5% and 15% on the basis of the total weight of said fluorinated polymer.

[0055] Said fluorinated polymer may also be a poly(vinylidene fluoride-trifluoroethylene and / or tetrafluoroethylene), preferably a poly(vinylidene fluoride-co-trifluoroethylene). In this case, said fluorinated polymer may preferably have a molar content in units of vinylidene fluoride of 25 to 95%, preferably of 55 to 80%, for example of 25 to 35%, or of 35 to 45%, or of 45 to 55%, or of 55 to 65%, or of 65 to 80%, or of 80 to 95%; and / or a molar content in units of trifluoroethylene and / or tetrafluoroethylene of 5 to 75%, preferably 20 to 45%, for example 5 to 10%, or 10 to 20%, or 20 to 30%, or 30 to 45%, or 45 to 55%, or 55 to 65%, or 65 to 75%.Said fluorinated polymer may be a poly(vinylidene fluoride-trifluoroethylene and / or tetrafluoroethylene-chlorofluoroethylene and / or chlorotrifluoroethylene), preferably a poly(vinylidene fluoride-ter-trifluoroethylene-ter-chlorofluoroethylene) or a poly(vinylidene fluoride-ter-trifluoroethylene-ter-chlorotrifluoroethylene).These fluoropolymers preferably have a molar content in vinylidene fluoride units of 25 to 80%, preferably 35 to 70%, for example 25 to 35%, or 35 to 45%, or 45 to 55%, or 55 to 70%, or 70 to 80%; and / or a molar content in trifluoroethylene and / or tetrafluoroethylene units of 3 to 60%, preferably 14 to 40%, for example 3 to 5%, 5 to 10%, 10 to 14%, 14 to 20%, or 20 to 30%, or 30 to 40%, or 40 to 50%, or 50 to 60%; and / or a molar content in chlorofluoroethylene and / or chlorotrifluoroethylene units of 2 to 20%, preferably 3 to 15%, preferably 4 to 12%, for example 2 to 3%, or 3 to 4%, or 4 to 5%, or 5 to 6%, or 6 to 7%, or 7 to 8%, or 8 to 9%, or 9 to 10%, or 10 to 12%, or 12 to 15%, or 15 to 18%, or 18 to 20%.

[0056] Said fluorinated polymer may optionally comprise repeating units derived from a monomer Ml” of formula RaRbC=C(Rc)C(O)Rd in which the substituents Ra, Rb and Rc are independently selected from the group consisting of H and Ci-C5 alkyl; Rd is selected from the group consisting of -NHC(CH3)2CH2C(O)CH3 or -ORd' with Rd' selected from the group consisting of H and Ci-Ci8 alkyl optionally substituted by one or more -OH, -CO2H, -SO3H, -PO3H, -OC(O)Rd”, -C(O)O-Rd” or a five- or ten-membered heterocycle comprising at least one nitrogen atom in its cyclic chain; Rd” being selected from the group consisting of Ci-C6 alkyl or C6-Ci2 aryl optionally substituted by one or more Group(s) -OH, -CO2H, -SO3H, -PO3H. Said heterocycle may be saturated, unsaturated, or aromatic. Said heterocycle may be monocyclic or bicyclic.Said heterocycle may be a pyrrole, pyrrolidine, pyridine, piperidine, pyrimidine, pyrazine, 1,4-dihydropyridine, indole, oxindole, isatin, quinoline, isoquinoline, quinazoline, imidazoline, pyrazolidine ring. 2-pyrrolidone, delta-lactam, succinimide, 2-imidazolidinone, 4-imidazolidinone. Said heterocycle may be substituted by one or more C1-C5 alkyl groups. As mentioned above, the alkyl Ci-Ci8 group is optionally substituted by said heterocycle. The latter may be linked to the alkyl chain by the nitrogen atom or any other atom forming the heterocycle. Preferably, the heterocycle is 2-pyrrolidone, delta-lactam, succinimide, 2-imidazolidinone, 4-imidazolidinone.The monomer Ml” may be of the formula RaRbC=C(Rc)C(O)Rd in which the substituents Ra, Rb and Rc are independently selected from the group consisting of H and C1-C5 alkyl; Rd is selected from the group consisting of -NHC(CH3)2CH2C(O)CH3 or -ORd' with Rd' selected from the group consisting of H and C1-C18 alkyl optionally substituted by one or more -OH, -CO2H, -SO3H, -PO3H, -OC(O)Rd”, -C(O)O-Rd” or a five- or ten-membered heterocycle comprising at least one nitrogen atom in its cyclic chain; Rd” being selected from the group consisting of Ci-C6 alkyl or C6-Ci2 aryl optionally substituted by one or more -OH, -CO2H, -SO3H, -PO3H. Preferably, the heterocycle is as defined above, in particular the heterocycle is 2-pyrrolidone, deltalactam, succinimide, 2-imidazolidinone, 4-imidazolidinone.Preferably, the substituent Rd' is selected from the group consisting of H, methyl, ethyl, propyl, n-butyl, isobutyl, t-butyl, n-dodecyl, amyl, isoamyl, hexyl, 2-ethylhexyl, lauryl, n-octyl, hydroxyethyl, hydroxybutyl, hydroxypropyl, ethyl substituted with a ureido group. In particular, said monomer Ml” has the formula RaRbC=C(Rc)C(O)Rd in which the substituents Ra and Rb are . H; Rcest H or CH3; Rd is -ORd' with Rd' selected from the group consisting of H, methyl, ethyl, propyl, n-butyl, isobutyl, t-butyl, hydroxypropyl, hydroxybutyl, 2-pyrrolidone, deltalactam, succinimide, 2-imidazolidinone, 4-imidazolidinone. More specifically, said monomer Ml” may be acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-dodecyl acrylate, amyl acrylate, isoamyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, diacetone acrylamide, lauryl acrylate, n-octyl acrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, methyl acrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, methacrylate of n-butyl,isobutyl methacrylate, t-butyl methacrylate, n-dodecyl methacrylate, amyl methacrylate, isoamyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, ureido methacrylate, the , monomers of the formula 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, said monomer M1” with an alkyl group having from 1 to 8 carbon atoms is preferred, and an alkyl group having from 1 to 5 carbon atoms is more preferable. Said fluorinated polymer may comprise one or more repeating units derived from said monomer M1” as defined herein.

[0057] According to another embodiment, said fluorinated polymer may comprise repeating units from a vinylidene fluoride monomer, repeating units from a fluorinated monomer Ml, repeating units from a non-fluorinated monomer Ml” of formula RaRbC=C(Rb)C(O)Rd; said monomers Ml and Ml” being as defined above.For example, said fluorinated polymer may comprise repeating units from a monomer being vinylidene fluoride, repeating units from a fluorinated monomer Ml being hexafluoropropene and repeating units from a non-fluorinated monomer Ml” selected from the group consisting of acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, hydroxypropyl methacrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, methyl acrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, the monomers of formula 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(CO2CH2CH2CH 2CH(CO2H)CH2CH2CO2H); and mixtures thereof.

[0058] When said fluorinated polymer comprises repeating units derived from monomer Ml”, these are present in a mass content of less than 5%, preferably less than 3% based on the total weight of said fluorinated polymer. Preferably, the mass content of repeating units derived from monomer Ml” may be between 0.01% and 5%, advantageously between 0.05% and 3%, preferably between 0.1% and 2%, in particular between 0.1% and 1% based on the total weight of said fluorinated polymer. Organic solvent

[0059] Preferably, said organic solvent is an aprotic solvent. An aprotic solvent is a solvent that does not contain labile hydrogen atoms. The term organic solvent includes mixtures of several organic solvents having a donor number as specified in this application.

[0060] Preferably, said organic solvent has a donor number greater than or equal to 5 kcal / mol. The donor index, or donor number, of a solvent represents the value -AH, AH being the enthalpy of the interaction between the solvent and antimony pentachloride (according to the method described in Journal of Solution Chemistry, vol. 13, no. 9, 1984).

[0061] According to a preferred embodiment, said organic solvent has a donor number greater than or equal to 6 kcal / mol, advantageously greater than or equal to 7 kcal / mol, preferably greater than or equal to 8 kcal / mol, more preferably greater than or equal to 9 kcal / mol, in particular greater than or equal to 10 kcal / mol.

[0062] According to a preferred embodiment, said organic solvent has a donor number less than or equal to 30 kcal / mol, advantageously less than or equal to 29 kcal / mol, preferably less than or equal to 28 kcal / mol, more preferably less than or equal to 27 kcal / mol, in particular less than or equal to 26 kcal / mol, more particularly less than or equal to 25 kcal / mol, preferably less than or equal to 24 kcal / mol, advantageously preferred less than or equal to 23 kcal / mol, preferably preferred less than or equal to 22 kcal / mol, more preferably preferred less than or equal to 21 kcal / mol, particularly preferred less than or equal to 20 kcal / mol.

[0063] Thus, according to a preferred embodiment, said organic solvent has a donor number greater than or equal to 5 kcal / mol, advantageously greater than or equal to 6 kcal / mol, preferably greater than or equal to 7 kcal / mol, more preferably greater than or equal to 8 kcal / mol, in particular greater than or equal to 9 kcal / mol, more particularly greater than or equal to 10 kcal / mol;and less than or equal to 30 kcal / mol, advantageously less than or equal to 29 kcal / mol, preferably less than or equal to 28 kcal / mol, more preferably less than or equal to 27 kcal / mol, in particular less than or equal to 26 kcal / mol, more particularly less than or equal to 25 kcal / mol, preferably less than or equal to 24 kcal / mol, advantageously preferred less than or equal to 23 kcal / mol, preferably preferred less than or equal to 22 kcal / mol, more preferably preferred less than or equal to 21 kcal / mol, particularly preferred less than or equal to 20 kcal / mol. ;

[0064] According to a particular embodiment, said organic solvent has a donor number of 10 to 30 kcal / mol, advantageously of 10 to 25 kcal / mol, preferably of 10 to 20 kcal / mol.

[0065] Said organic solvent may be selected in particular from among esters, carbonates, nitriles or dinitriles, ethers or diethers, amines, ketones or phosphines provided that it has a donor number as specified in this application and that it is aprotic. Combinations of these may also be used as an organic solvent.

[0066] By way of non-limiting example, solvents may be cited as: acetone, anisole, methyl isobutyl ketone (MIBK), cyclopentanone, isobutyl isobutyrate (IBIB), éthyle acétate, propylène glycol monomethyl éther acétate, 1,3,2-dioxathiolan-2-oxide, 1,2-dimethoxyethane, 1,3,3-trimethyl-2-oxabicyclo[2.2.2]octane, l,3-dimethyl-2-imidazolidinone,, l,3-dioxolan-2-one, 1,3-dioxolane, 2,2,2-trifluoro-N,N-dimethylacetamide, 2,2,4,4-tetramethyl-3-pentanone, 2,2,4-trimethylpentan-3-one, 2,2,5,5-tetramethylhexan-3-one, 2,2,6,6-tetramethyl-4-heptanone, 2,2-dimethylpentan-3-one, 2,3-butanedione, 2,4-dimethyl-3-pentanone, 2,6-dimethyl-4-heptanone, 2-butanone, 2-methylpentan-3-one, 2-methylpropanenitrile, 2-methyltetrahydrofuran, 2-pentanone, 2-phenylacetonitrile, 3,3-dimethyl-2-butanone, 3-methyl-2-butanone, 3-pentanone, 4-methyl-2-oxo-1,3-dioxolane, 4-methyl-2-pentanone, acétonitrile, acétophénone, benzaldéhyde, benzonitrile, benzophénone, bis(2-chloroethyl) éther, butanenitrile, butyl acétate, chloroacetonitrile,, cyclohexanone, cyclopentanone, dibenzyl ether, dibutyl ether, diethyl carbonate, diethyl éther, diisopropyl éther, dimethyl carbonate,dimethylcyanamide, dioxane, diphenylphosphinic chloride, dipropyl ether, ethyl 2,2-dimethylpropanoate, ethyl 2-methylpropanoate, ethyl benzoate, ethyl butanoate, ethyl chloroacetate, ethyl chloroformate, ethyl formate, ethyl propanoate, formamide, isopropyl 2,2-dimethylpropanoate, isopropyl acetate, isopropyl pivalate, methyl 2,2-dimethylpropanoate, methyl acetate, methyl benzoate, methyl propanoate, methyl propyl ether, N,N-dimethylbenzylamine, N,N-dimethylcarbamoyl chloride, N,N-dimethylformamide, N,N-dimethyltrifluoroacetamide, N,N-dimethylurethane, N-methylpyrrolidone, oxane, oxolan-2-one, phenylphosphonic dichloride, phenylphosphonic difluoride phosphorus oxychloride, propanenitrile, propyl acetate, sulfolane, tetrahydrofuran, tributyl phosphate, triethyl phosphate, trimethyl phosphate, tripyrrolidinophosphine oxide, l-butyl-3-methylimidazolium tetrafluoroborate,, l-butyl-3-methylimidazolium bis-(trifluoromethylsulfonyl)imide,butyl-methylpyrrolidinium bis-(trifluoromethylsulfonyl)imide, butyl-methylpiperidinium bis-(trifluoromethylsulfonyl)imide, ethyl-dimethyl-propylammonium bis-(trifluoromethylsulfonyl)imide, triethylsulfonium bis-(trifluoromethylsulfonyl)imide. , Use

[0067] The compositions according to the present invention can be used in a solid composite electrolyte. Thus, the present invention provides a solid composite electrolyte comprising one of the compositions according to the present invention. Preferably, said solid composite electrolyte consists of one of the compositions according to the present invention.

[0068] Said solid composite electrolyte can be integrated into a battery. Said solid composite electrolyte can be disposed between a positive electrode and a negative electrode or form part of the composition of the positive or negative electrode.

[0069] Said positive electrode may include a current collector on which has been deposited an electrode composition comprising an active material, possibly a binder, and optionally a conductive agent and / or a solid composite electrolyte according to the present invention.

[0070] Said negative electrode may include a current collector on which has been deposited an electrode composition comprising an active material, possibly a binder, and optionally a conductive agent and / or a solid composite electrolyte according to the present invention.

[0071] In the case of a positive electrode, the active material may be chosen from the group consisting of a composite metal chalcogenide represented by a general formula LiMY2, in which M denotes at least one species of transition metal such as Co, Ni, Fe, Mn, Cr, Al, and V; and Y denotes a chalcogen, such as O or S. Among these, a lithium-based composite metal oxide represented by a general formula of LiMO2 is preferred, where M is the same as above. Preferred examples of these may include: LiCoO2, LiNiO2, LiNiCo2, XO2 (0 <x<l), Lix(NioJsCooji5AIojo5)02, Li(Nii / 3Coi / 3Mni / 3)O2; Li (Nio,6Coo,2Mnoj2)02, Li (Nio> 8CoojiMn0ji)02 and LiMn2O4 with spinel structure and LiMnij5Nioj5O4.The active material can thus be chosen from the group consisting of LiCoO2, Li(Ni, Co, Al)O2, Li(i+x)NiaMnbCoc (x represents a real number of 0 or more, 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, a LiMn spinel substituted by a different element having a composition represented by Lii+xMn2 x yMyO4, M representing at least one metal chosen from Al, Mg, Co, Fe, Ni, and Zn, x and y independently representing a a real number between 0 and 2, lithium titanate LixTiOy where x and y independently represent a real number between 0 and 2, and a lithium metal phosphate having a composition represented by LiMPO4, M representing Fe, Mn, Co, or Ni. These active materials can be coated with inorganic or organic coatings, such as LiNbO3.Alternatively, the active material intended for use in forming a positive electrode can also be sulfur or Li2S.

[0072] In the case of a negative electrode, the active material may preferably comprise a carbon-based material and / or a silicon-based material. Alternatively, the negative electrode may be lithium-based, such as lithium metal, or silicon. In some embodiments, the carbon-based material may be, for example, graphite, such as natural or artificial graphite, graphene, or carbon black. These materials may be used alone or in a mixture of two or more of them. The carbon-based material is preferably graphite. Carbonaceous material may preferably be used in the form of particles having an average diameter of 0.5–100 µm. The silicon-based compound may be one or more elements selected from the group consisting of chlorosilane, alkoxysilane, aminosilane, fluoroalkylsilane, silicon, silicon chloride, silicon carbide, and silicon oxide. More specifically, the silicon-based compound may be silicon oxide or silicon carbide. When present, at least one silicon-based compound is included in the active substance in an amount ranging from 1 to 30% by weight, preferably 5 to 10% by weight relative to the total weight of the active material.

[0073] Examples of conducting agents may include: carbon materials, such as carbon black, fine graphite powder and fibers, and fine powder and fibers of metals, such as nickel and aluminum.

[0074] The binder used in electrode compositions may be a fluorinated polymer as described in this application, acrylic or acrylate polymers, polyacrylonitrile, or styrene-butadiene type polymers, or a mixture thereof. The presence of a binder in the electrode compositions depends on their formulation. For example, if the electrode composition includes a solid composite electrolyte according to the present invention, this electrolyte may act as a binder for the active material. However, even in the presence of said solid composite electrolyte, a binder may be added to improve mechanical strength. Examples

[0075] In the examples below, three fluorinated polymers were used: - PVDF A: Copolymer of vinylidene fluoride and hexafluoropropylene having a melt viscosity of 14 kPoise measured at 230°C at a shear rate of 100 s⁻¹ according to ASTM D3835 (hexafluoropropylene content of 17%) - PVDF B: Homopolymer of vinylidene fluoride having a melt viscosity of 8 kPoise measured at 230°C at a shear rate of 100 s⁻¹ according to ASTM D3835 - PVDF C: Homopolymer of vinylidene fluoride having a melt viscosity of 50 kPoise measured at 230°C at a shear rate of 100 s⁻¹ according to ASTM D3835

[0076] The solid inorganic particles used in the examples are of formula Li6PS 5C1 having a Young's modulus of 22.1 GPa.

[0077] Conductivity measurement

[0078] Ionic conductivity measurements were performed using electrochemical impedance spectroscopy (EIS). A sinusoidal potential perturbation was Applied with a BioLogic VMP 300, varying the sinusoidal frequency between 7 MHz and 100 MHz. The amplitude of the applied perturbation depends on the temperature and the amount of polymer used. At 20°C, for polymer contents below 15%, a 30 mV perturbation is applied. At 30% polymer by mass, the sinusoidal perturbation is increased to 50 mV. To ensure good contact between the Li6PS5Cl grains, the cells were sealed at 125 MPa for EIS characterization. A Clima Temperature System (CTS) oven was programmed to maintain a stable temperature independent of the ambient temperature.

[0079] Dry compositions are prepared according to the following protocol by varying the type of fluorinated polymer used and its content in the composition.

[0080] The two materials (Li6PS5Cl and the fluorinated polymer) are mixed, in the desired ratio, for 10 minutes in a mortar using a dry process, in an argon glove box with [H2O] < 1 ppm and [O2] < 1 ppm. Different solid electrolyte compositions were investigated by varying the mass content of the fluorinated polymer and the type of fluorinated polymer. The mixture is pressed at 250 MPa for 10 minutes in a homemade 7 mm diameter cell to obtain a pellet.

[0081] The conductivity obtained for each of the compositions is detailed in Table 1 below.

[0082] [Tables 1] Examples Fluorinated Polymer Polymer Mass Content (%)* Relative Conductivity (%)** 1 (comparative) na 0 100 2 (invention) PVDF A 3 93 3 (invention) PVDFB 3 89 4 (comparative) PVDFC 3 77 5 (invention) PVDF A 5 83 6 (invention) PVDFB 7 75 7 (comparative) PVDFC 7 57 8 (invention) PVDF A 10 78 9 (invention) PVDF A 15 66

[0083] ^Mass content of fluorinated polymer in the composition

[0084] **relative conductivity measured with respect to example 1 (without fluorinated polymer) at 20°C. Taking the conductivity of LPSCl to be 2.3 mS.cm 7

[0085] As we can see, the ionic conductivity is better when a fluorinated polymer having a viscosity less than 45 kPoise is used in the composition.

[0086] Current density test

[0087] Li plating-stripping measurements were performed using lithium-indium alloy (InLi) electrodes. The solid electrolyte was placed between the two electrodes. The experiments were carried out at 25°C, and the current density was alternately set to 0.035 mA.cm² and -0.035 mA.cm², representing one cycle. Three cycles were performed for each current step. The current density was gradually increased up to 3.5 mA.cm².

[0088] This test makes it possible to determine the maximum applicable current as a function of the solid composite electrolyte considered. Better results are obtained with a solid composite electrolyte prepared from PVDF B. Indeed, the potential plateaus are, for each current, less polarized with the solid composite electrolyte containing PVDF B. With the solid composite electrolyte containing PVDF C, a strong polarization is observed from i = 0.350 mA.cm² as well as short circuits for a current i = 3.50 mA.cm² due to disconnections at the InLi / / composite electrolyte interfaces.

[0089] Solvent-based composition with a homopolymer-type fluorinated polymer

[0090] The ionic conductivity obtained for a hybrid electrolyte using solvent-based PVDF B (ethyl acetate) is determined as a function of the polymer percentage in Table 2 below. The composition also includes 1 mL of ethyl acetate and 90 to 100% of Li6PS5Cl, depending on the amount of fluorinated polymer added. Polymer mass content (% PVDF B)* Conductivity (%) ** 0 100 3 63 5 54 7 45 10 34

[0092] ^Mass content of fluorinated polymer in the composition

[0093] **relative conductivity measured with respect to LPSCl (without fluorinated polymer) at 20°C. Taking the conductivity of LPSCl to be 2.3 mS.cm 7

[0094] Similar to what is described above, plating-stripping measurements were performed with solid composite electrolytes obtained by a solvent process. Ethyl acetate is evaporated to obtain a homogeneous Li6PS5Cl / PVDF B mixture. The experiment consists of applying an alternately positive and negative current with an absolute amplitude of 2.1 mA.cm². It was found that the addition of the fluorinated polymer PVDF B according to the invention stabilizes the potential plateaus, delaying hyperpolarization, which is synonymous with mechanical disconnection.

Claims

Demands

1. Dry composition comprising particles of a fluorinated polymer and solid inorganic particles characterized in that said solid inorganic particles have a Young's modulus between 1 and 100 GPa and in that said fluorinated polymer has a melt viscosity of less than 45 kPoise measured at 230°C at a shear rate of 100 s⁻¹ according to ASTM D3835.

2. Dry composition according to the preceding claim characterized in that said solid inorganic particles contain at least one sulfur atom and at least one phosphorus atom and optionally at least one element from the halogen column.

3. Dry composition according to any one of the preceding claims characterized in that said solid inorganic particles are selected from the group consisting of: - lithium tin sulfide phosphorus (“Isps”) such as Li₂OSnP₂S₁₂; - Lithium sulfide phosphorus (“Ips”) of formula (Li₂S)x(P₂S₅)y, wherein x + y = l and 0 < x < 1, Li₇P₃Sn, Li₇PS₆, Li₄P₂S₆, Li₇P₃Si₂ and Li₃PS₄; - doped LPS such as Li₂CuPS₄, Li₁₂Zn₂xPS₄, in which 0 < x < 1, Li₃.₃Mg₀.33P2S6, and Li4 3xScxP2S6, where 0 < x < 1; - Lithium sulfide phosphorus oxygen ("LPSO") of formula LixPySzO, where 0.33 < x < 0.67, 0.07 < y < 0.2, 0.4 < z < 0.55, 0 <w<0,15; - Lithium sulfure phosphore ("LXPS") avec x Si, Ge, Sn, As, Al, tel que Lii0GeP2Si2 ou Lii0SiP2Si2 ; - Lithium sulfure phosphore oxygène ("LXPSO") avec x Si, Ge, Sn, As, Al ; - Lithium sulfure silice (“LSS”) tel que Li2S-P2S5- SiS2, Li2S- P2S5-SiS2-LiCl, Li2S-SiS2-P2S5, Li2S-SiS2-P2S5-LiI, Li9 54Si i.74Pi.44Sii.7C10.3 ; Li4PS4Cl Li15P3Si6Cl3, Li7P2S8Cl et Li7P2S8I ; - Matériaux de formule Li6PS5Y dans laquelle Y est Cl, Br ou I tel que ; Li6 XPS5 XYUx, dans laquelle 0 < x < 0,5 ; de préférence Li6PS5Cl ;. and mixtures thereof.

4. A dry composition according to any one of the preceding claims characterized in that said fluorinated polymer comprises repeating units derived from vinylidene fluoride and optionally repeating units of a monomer Ml selected from the group consisting of vinyl fluoride; trifluoroethylene; chlorotrifluoroethylene; 1,2-difluoroethylene; tetrafluoroethylene; hexafluoropropylene; perfluoro(alkyl vinyl) ethers such as perfluoro(methylvinyl) ether (PMVE), perfluoro(ethyl vinyl) ether (PEVE) and perfluoro(propylvinyl) ether (PPVE); perfluoro(1,3-dioxole); perfluoro(2,2-dimethyl-1,3-dioxole) (PDD); the product of formula CF2=CFOCF2CF(CF3)OCF2CF2X in which X is SO2F, CO2H, CH2OH, CH2OCN or CH2OPO3H; the product of formula CF2=CFOCF2CF2SO2F; the product of formula F(CF2)nCH2OCF=CF2 in which n is 1, 2, 3, 4 or 5; the product of formula R1CH2OCF=CF2 in which R1 is hydrogen or F(CF2)m and m is 1, 2, 3 or 4;the product of formula R2OCF=CH2 in which R2 is F(CF2)p and p is 1, 2, 3 or 4; perfluorobutyl ethylene (PFBE); 3,3,3-trifluoropropenc and 2-trifluoromethyl-3,3,3-trifluoro-l-propene or a mixture thereof.;

5. Dry composition according to any one of the preceding claims characterized in that said fluorinated polymer is a homopolymer of vinylidene fluoride or a polymer comprising repeating units derived from vinylidene fluoride and repeating units derived from a monomer Ml selected from the group consisting of trifluoroethylene, chlorotrifluoroethylene, 1,2-difluoroethylene, chlorofluoroethylene, tetrafluoroethylene and hexafluoropropylene or a mixture thereof.

6. A dry composition according to any one of the preceding claims, characterized in that said fluorinated polymer is a homopolymer of vinylidene fluoride or a polymer selected from the group consisting of: - the copolymer comprising repeating units derived from vinylidene fluoride and repeating units derived from hexafluoropropylene, - the copolymer comprising repeating units derived from vinylidene fluoride and repeating units derived from trifluoroethylene, - a copolymer comprising repeating units derived from vinylidene fluoride and repeating units derived from chlorotrifluoroethylene, - a copolymer of repeating units derived from vinylidene fluoride and repeating units derived from tetrafluoroethylene, and - a fluorinated terpolymer selected from: a terpolymer comprising repeating units derived from vinylidene fluoride, repeating units derived from trifluoroethylene and repeating units derived from chlorofluoroethylene, a terpolymer comprising repeating units derived from vinylidene fluoride, repeating units derived from trifluoroethylene and repeating units derived from chlorotrifluoroethylene, a terpolymer comprising repeating units derived from vinylidene fluoride, repeating units derived from trifluoroethylene and repeating units derived from hexafluoropropylene, a terpolymer comprising repeating units derived from vinylidene fluoride,repeating units derived from tetrafluoroethylene and repeating units derived from chlorofluoroethylene, the terpolymer comprising repeating units derived from vinylidene fluoride, repeating units derived from tetrafluoroethylene and repeating units derived from chlorotrifluoroethylene, and the terpolymer comprising repeating units derived from vinylidene fluoride, repeating units derived from tetrafluoroethylene and repeating units derived from hexafluoropropylene, or a mixture of the aforementioned copolymers or terpolymers.

7. Dry composition according to any one of the preceding claims characterized in that said fluorinated polymer comprises a mass content of vinylidene fluoride repeating units of at least 50% by weight on the basis of the total weight of said fluorinated polymer.

8. Dry composition according to any one of the preceding claims characterized in that it contains less than 0.1% by weight of lithium salt on the basis of the total weight of said composition, said lithium salt being different from said solid inorganic particles, preferably said composition is devoid of lithium salt.

9. Solid composite electrolyte comprising, preferably consisting of, said dry composition according to any one of the preceding claims.

10. All-solid-state battery comprising said solid composite electrolyte according to the preceding claim.

11. Composition comprising particles of a fluorinated polymer, an organic solvent and solid inorganic particles characterized in that: - said solid inorganic particles have a Young's modulus between 1 and 100 GPa; - said fluorinated polymer is a homopolymer having a melt viscosity of less than 45 kPoise measured at 230°C at a shear rate of 100 s⁻¹ according to ASTM D3835; - said organic solvent is an aprotic solvent and has a donor number greater than or equal to 5 kcal / mol; and - said composition comprises less than 0.1% by weight of lithium salt on the basis of the total weight of said composition, said lithium salt being different from said solid inorganic particles, preferably said composition is devoid of lithium salt.

12. Composition according to the preceding claim characterized in that said inorganic particles are as defined in claim 2 or 3.

13. Composition according to any one of the preceding claims 11 or 12 characterized in that said fluorinated polymer is a homopolymer derived from a monomer M1 selected from the group consisting of vinyl fluoride; vinylidene fluoride, trifluoroethylene; chlorotrifluoroethylene; 1,2-difluoroethylene and tetrafluoroethylene; preferably said fluorinated polymer is a homopolymer of vinylidene fluoride.

14. Solid composite electrolyte comprises, preferably consisting of, said composition according to any one of the preceding claims 11 to 13.

15. All-solid-state battery comprising said solid composite electrolyte according to the preceding claim.