Solid composite electrolyte

Abstract

The present invention relates to a solid composite electrolyte comprising: a) at least one fluoroelastomer; and b) at least one sulfide-based solid, ionically conductive inorganic particle different from a lithium salt, wherein a) the fluoroelastomer comprises repeat units derived from i) vinylidene difluoride (VDF); and ii) 15.0 to 80.0 mol % of at least one C2 to C8 chloro- and / or bromo- and / or iodofluoroolefin (mol % is based on the total moles of repeat units), wherein the solid composite electrolyte does not contain a lithium salt; to a slurry for producing a solid composite electrolyte comprising: a) a fluoroelastomer; b) sulfide-based solid, ionically conductive inorganic particle different from a lithium salt; and c) at least one non-aqueous solvent, wherein the slurry does not contain a lithium salt; and a solid battery comprising a positive electrode, a negative electrode, and a membrane, wherein at least one of them comprises the solid composite electrolyte according to the present invention. The present invention also relates to a binder solution for a solid-state battery comprising a) at least one fluoroelastomer and c) at least one non-aqueous solvent.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to European Patent Application No. 22189656.6, filed August 10, 2022, the entire contents of which are incorporated herein by reference for all purposes.

[0002] The present invention relates to a solid composite electrolyte comprising a) at least one fluoroelastomer and b) at least one sulfide-based solid, ionically conductive inorganic particle different from a lithium salt, wherein a) the fluoroelastomer comprises repeat units derived from i) vinylidene difluoride and ii) 15.0 to 80.0 mol % of at least one C2 to C8 chloro- and / or bromo- and / or iodofluoroolefin (mol % is based on the total moles of repeat units), wherein the solid composite electrolyte does not contain a lithium salt; to a slurry for producing the solid composite electrolyte comprising a) a fluoroelastomer, b) sulfide-based solid, ionically conductive inorganic particle different from a lithium salt, and c) at least one non-aqueous solvent, wherein the slurry does not contain a lithium salt; to an electrode comprising the solid composite electrolyte according to the present invention, d) at least one electroactive material, and optionally e) at least one conductive agent; and to a solid battery comprising a positive electrode, a negative electrode, and a membrane, at least one of which comprises the solid composite electrolyte according to the present invention. The present invention also relates to a binder solution for solid-state batteries comprising a) at least one fluoroelastomer according to the present invention and c) at least one non-aqueous solvent. [Background technology]

[0003] Lithium-ion batteries have held a dominant position in the market of rechargeable energy storage devices for decades thanks to their many advantages, such as light weight, reasonable energy density, and good cycle life. Nevertheless, better safety and higher energy density have been constantly required with the development of high power applications such as electric vehicles, hybrid electric vehicles, grid energy storage, etc.

[0004] Solid-state batteries are therefore considered to be the next generation of energy storage devices, in which highly flammable liquid electrolytes are replaced by solid electrolytes that can substantially eliminate the risk of fire and / or explosion. Organic polymers, inorganic materials, and composite materials have been actively researched as solid electrolytes, each of which has its own advantages and disadvantages. In particular, composite materials, i.e., inorganic electrolytes dispersed in polymers, such as those containing sulfide particles dispersed in a polymer matrix, are considered to be the most promising solutions on an industrial scale, given the high ionic conductivity of sulfide-based solid electrolytes, as well as the good mechanical properties and easy processability of polymers. Nevertheless, there are also drawbacks that need to be addressed, such as poor solvent compatibility of sulfide materials, which significantly limits the choice of polymers that can be used to fabricate electrolytes; poor adhesion to electrode current collectors; the rather complicated process for fabricating solid composite electrolytes; and the relatively weak flexibility of solid composite electrolytes.

[0005] U.S. Patent Application Publication No. 2015 / 096169 A1 (Kureha Corporation and Toyota) discloses that a positive electrode for a sulfide-based solid-state battery formed from a slurry containing a fluorine-based copolymer having a specific amount of VDF units (40-70 mol%) exhibits good adhesion to the current collector.

[0006] WO 2021 / 039950 (Fujifilm) describes an inorganic solid electrolyte-containing composition comprising an inorganic solid electrolyte, a polymer binder, and a dispersion medium, where the polymer binder comprises a fluorine-based copolymer containing a VDF component and 21 to 65 mol% hexafluoropropylene (HFP) component. The composition exhibits greater than 60% adsorption to the inorganic solid electrolyte and is effective in controlling excessive viscosity increase, re-solidification, or sedimentation of the inorganic particles, enabling the achievement of solid-state batteries with excellent cycling characteristics. In particular, the polymer binder exhibits a tensile failure strain of 500% or more.

[0007] However, there remains a continuing need in the art for sulfide-based solid composite electrolytes that exhibit outstanding adhesion to current collectors and / or better flexibility, while maintaining high ionic conductivity and good mechanical properties. Summary of the Invention

[0008] A first object of the present invention is a solid composite electrolyte comprising a) at least one fluoroelastomer and b) at least one sulfide-based solid, ionically conductive inorganic particle different from a lithium salt, wherein a) the fluoroelastomer comprises repeat units derived from i) vinylidene difluoride (VDF) and ii) 15.0-80.0 mol % of at least one C2-C8 chloro- and / or bromo- and / or iodo-fluoroolefin (mol % is with respect to the total moles of repeat units), and the solid composite electrolyte does not contain a lithium salt.

[0009] A second object of the present invention is a slurry for producing a solid composite electrolyte comprising a) a fluoroelastomer, b) sulfide-based solid, ionically conductive inorganic particles different from a lithium salt, and c) at least one non-aqueous solvent, wherein the slurry does not contain a lithium salt.

[0010] A third object of the invention is an electrode comprising a solid composite electrolyte according to the invention, d) at least one electroactive material and, optionally, e) at least one conductive agent.

[0011] A fourth object of the present invention is a solid-state battery comprising a positive electrode, a negative electrode and a membrane arranged between the positive and negative electrodes, wherein at least one of the positive electrode, the negative electrode and the membrane comprises the solid composite electrolyte according to the present invention, optionally d) at least one electroactive material and / or e) at least one conductive agent.

[0012] A fifth object of the present invention is a binder solution for solid-state batteries comprising a) at least one fluoroelastomer according to the invention and c) at least one non-aqueous solvent.

[0013] Surprisingly, it has been found by the inventors that the solid composite electrolyte according to the present invention can deliver a particularly advantageous combination of properties, such as excellent adhesion to the current collector, better flexibility, and the like. [Brief explanation of the drawings]

[0014] [Figure 1] Cross-section of an AC impedance spectroscopy pressure cell developed within Solvay to measure the ionic conductivity of films. In the pressure cell, the film is pressed between two stainless steel electrodes during impedance measurements. [Figure 2] Figure 1 shows an equivalent circuit for modeling the conductive behavior of solid composite electrolytes, where R1 and R2 represent the bulk and grain boundary resistances, respectively, and Q2 and Q3 represent the grain boundary and electrode contributions, respectively. DETAILED DESCRIPTION OF THE INVENTION

[0015] Ratios, concentrations, amounts, and other numerical data may be expressed in range format herein. It should be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the upper and lower limits of the range, but also all individual numerical values or subranges encompassed within the range, as if each numerical value and subrange were explicitly recited. In the context of the present invention, the term "weight percent" (wt%) refers to the content of a particular component in a mixture, calculated as the ratio between the weight of the component and the total weight of the mixture. As used herein, the concentration of a repeat unit in "percent by mole" (mol%) refers to the concentration relative to the total number of repeat units in the polymer, unless otherwise specified.

[0016] It should be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the invention as claimed. Accordingly, various changes and modifications described herein will be apparent to those skilled in the art. Additionally, descriptions of well-known functions and constructions may be omitted for clarity and brevity.

[0017] The present invention provides a) at least one fluoroelastomer; b) at least one sulfide-based solid, ionically conductive inorganic particle different from the lithium salt; A solid composite electrolyte comprising: a) the fluoroelastomer is i) vinylidene difluoride (VDF); and ii) 15.0 to 80.0 mol % of at least one C2 to C8 chloro and / or bromo and / or iodofluoroolefin (mol % is based on the total moles of repeating units) and a repeat unit derived from The present invention provides a solid composite electrolyte that does not contain a lithium salt.

[0018] In one embodiment, ii) the C2 to C8 chloro and / or bromo and / or iodofluoroolefins account for 15.0 to 65.0 mol %, preferably 15.0 to 50.0 mol % (mol % is based on the total moles of repeating units).

[0019] In another embodiment, ii) the C2 to C8 chloro and / or bromo and / or iodofluoroolefins are selected from the group consisting of 1,1-chlorofluoroethylene (CFE), chlorodifluoroethylene (CDFE), bromotrifluoroethylene, chlorotrifluoroethylene (CTFE), 1,2-dichloro-1,2-difluoroethylene, iodotrifluoroethylene, and combinations thereof.

[0020] In certain embodiments, ii) the C2 to C8 chloro and / or bromo and / or iodofluoroolefin is cis-1,2-dichloro-1,2-difluoroethylene or trans-1,2-dichloro-1,2-difluoroethylene, preferably trans-1,2-dichloro-1,2-difluoroethylene.

[0021] In another particular embodiment, ii) the C2-C8 chloro and / or bromo and / or iodofluoroolefin is chlorotrifluoroethylene (CTFE).

[0022] In a preferred embodiment, a) the fluoroelastomer comprises repeat units derived from VDF and CTFE.

[0023] In a more preferred embodiment, a) the fluoroelastomer comprises repeat units derived from 80.0 mol % VDF and 20.0 mol % CTFE.

[0024] In another more preferred embodiment, a) the fluoroelastomer comprises repeat units derived from 70.0 mol % VDF and 30.0 mol % CTFE.

[0025] In another more preferred embodiment, a) the fluoroelastomer comprises repeat units derived from 60.0 mol % VDF and 40.0 mol % CTFE.

[0026] In one embodiment, a) the fluoroelastomer further comprises iii) repeating units derived from at least one C2-C8 fluoroolefin, which are different from i) and ii).

[0027] In the present invention, iii) the C2 to C8 fluoroolefin is - C2-C8 perfluoroolefins, such as tetrafluoroethylene (TFE), hexafluoropropylene (HFP); - hydrogen-containing C2-C8 fluoroolefins, such as vinyl fluoride (VF), trifluoroethylene (TrFE), hexafluoroisobutylene; - Formula CH2=CH-R f (In the formula, R f is a C1-C6 (per)fluoroalkyl group); - Formula CF2=CFOR f (In the formula, R f is a C1-C6 (per)fluoroalkyl group); (per)fluoroalkyl vinyl ether (PAVE); Formula CF2 = CFOX (wherein X is C1 to C 12 (per)fluorooxyalkyl vinyl ether (which is (per)fluoro)oxyalkyl); - Formula: [ka] (wherein R f3 , R f4 , R f5 , and R f6 are independently selected from C1-C6 (per)fluoroalkyl groups containing a fluorine atom and optionally at least one oxygen atom; - Formula CFX2=CX2OCF2OR” f (In the formula, R”f is selected from linear or branched C1-C6 (per)fluoroalkyl; C5-C6 cyclic (per)fluoroalkyl; and linear or branched C2-C6 (per)fluorooxyalkyl containing 1-3 catenary oxygen atoms, X2 is F or H; preferably R" f (per)fluoroalkoxyvinyl ethers (MOVE) of the formula -CF2CF3(MOVE1), -CF2CF2OCF3(MOVE2), or -CF3(MOVE3), where X2 is F; and - combinations thereof is selected from the group consisting of:

[0028] In certain embodiments, iii) the C2-C8 fluoroolefin is selected from the group consisting of vinyl fluoride (VF), trifluoroethylene (TrFE), tetrafluoroethylene (TFE), hexafluoropropylene (HFP), hexafluoroisobutylene, and combinations thereof.

[0029] In the present invention, the fluoroelastomers may be produced by suspension or emulsion polymerization processes.

[0030] In the present invention, the term "fluoroelastomer" is intended to denote fluoropolymer resins that serve as building blocks for obtaining true elastomers, which are defined by ASTM Special Technical Bulletin No. 184 as materials that can be stretched to twice their natural length at room temperature and that simultaneously return to within 10% of their original length when released after being held under tension for 5 minutes.

[0031] Fluoroelastomers are generally amorphous and exhibit a low degree of crystallinity, i.e., have less than 20% by volume of crystalline phase, and have a glass transition temperature (T g In most cases, the fluoroelastomer advantageously has a T of less than 10°C, preferably less than 5°C, more preferably less than 0°C, and even more preferably less than -5°C. g It has.

[0032] The term "amorphous" is intended herein to mean a polymer having a heat of fusion of less than 5.0 J / g, preferably less than 3.0 J / g, and more preferably less than 2.0 J / g, as measured by differential scanning calorimetry (DSC) at a heating rate of 10°C / min according to ASTM D3418.

[0033] In the present invention, the term "sulfide-based solid, ionically conductive inorganic particles" is not particularly limited as long as it is a solid electrolyte material that contains sulfur atoms in its molecular structure or composition.

[0034] The sulfide-based solid, ionically conductive inorganic particles preferably contain Li, S, and an element from Groups 13-15, such as P, Si, Sn, Ge, Al, As, Sb, or B, to increase Li-ion conductivity.

[0035] The sulfide-based solid, ionically conductive inorganic particles according to the present invention preferably comprise: - Li 10 SnP2S 12 Lithium tin phosphorus sulfide ("LSPS") materials, such as; - Formula (Li2S) x -(P2S5) y (wherein x+y=1 and 0≦x≦1), Li7P3S 11 , Li7PS6, Li4P2S6, Li 9.6 P3S 12 and lithium phosphosulfide ("LPS") materials, such as glasses, crystalline, or glass-ceramics of the type Li3PS4; - Li2CuPS4, Li 1+2x Zn 1-x PS4 (in the formula, 0≦x≦1), Li 3.33 Mg 0.33 P2S6, and Li 4-3x Sc x Doped LPS, such as P2S6 (where 0≦x≦1); - Expression Li x P y S zLithium Phosphorus Sulfide Oxygen (“LPSO”) materials of formula O, where 0.33≦x≦0.67, 0.07≦y≦0.2, and 0.4≦z≦0.55; - Li 10 SnP2S 12、 Li 10 GeP2S 12 , Li 10 SiP2S 12 and X-containing lithium phosphorus sulfide materials ("LXPS"), where X is Si, Ge, Sn, As, or Al, such as Li2S-P2S5-SnS; - X-containing lithium phosphorus sulfide oxygen ("LXPSO"), where X is Si, Ge, Sn, As, or Al; - Li2SiS3, Li2S-P2S5-SiS2, Li2S-P2S5-SiS2-LiCl, Li2S-SiS2-P2S5, Li2S-SiS2-P2S5-LiI, Li2S-SiS2-LiI, Li2S-SiS2, Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 Lithium silicon sulfide ("LSS") materials, such as Li2S-SiS2-Al2S3; - Lithium boron sulfide materials, such as Li3BS3 and Li2S-B2S3-LiI; - Li 0.8 Sn 0.8 S2, Li4SnS4, Li 3.833 Sn 0.833 As 0.166 Lithium tin sulfide and lithium arsenide materials, such as S4, Li3AsS4-Li4SnS4, and Ge-substituted Li3AsS4; - Li4PS4Cl 、 Li7P2S8Cl, Li7P2S8I, and the like a PS b X c (wherein X represents at least one halogen element selected from the group consisting of Cl, Br, and I, or a combination thereof; a represents a number from 2.0 to 7.0; b represents a number from 3.5 to 6.0; and c represents a number from 0 to 3.0); and - combinations thereof is selected from the group consisting of:

[0036] In a more preferred embodiment, the sulfide-based solid, ionically conductive inorganic particles have the general formula Li a PS b X c and more particularly, argyrodite-type sulfide materials of the formula Li6PS5X, where X is Cl, Br, or I.

[0037] In another preferred embodiment, the argyrodite-type sulfide material of formula Li6PS5Y is sulfur and / or lithium deficient, e.g., Li 6-x PS 5-x Cl 1+x , or doped with heteroatoms.

[0038] Particularly preferred sulfide-based solid ionically conductive particles are lithium tin phosphosulfide (“LSPS”) materials (e.g., Li 10 SnP2S 12 ) and argyrodite-type sulfide materials (e.g., Li6PS5Cl).

[0039] In one embodiment, b) the amount of sulfide-based solid, ionically conductive inorganic particles is at least 40.0 wt.-%, preferably at least 60.0 wt.-%, more preferably at least 70.0 wt.-%, even more preferably at least 80.0 wt.-%, most preferably at least 90.0 wt.-%, and / or at most 99.8 wt.-%, preferably at most 99.5 wt.-%, more preferably at most 99.0 wt.-%, most preferably at most 98.0 wt.-%, based on the total weight of the solid composite electrolyte.

[0040] In certain embodiments, the amount of b) sulfide-based solid, ionically conductive inorganic particles is 40.0 to 99.8 wt. %, preferably 60.0 to 99.5 wt. %, more preferably 70.0 to 99.0 wt. %, even more preferably 80.0 to 99.0 wt. %, and most preferably 90.0 to 99.0 wt. %, based on the total weight of the solid composite electrolyte.

[0041] In a more specific embodiment, b) the amount of sulfide-based solid, ionically conductive inorganic particles is 95.0 to 99.0 wt %, based on the total weight of the solid composite electrolyte.

[0042] In the present invention, b) the at least one sulfide-based solid, ionically conductive inorganic particle is different from the lithium salts conventionally used as essential components of lithium secondary batteries.

[0043] The term "lithium salt" is intended herein to mean a substance that must be dissolved in a solvent to ensure ionic conduction.

[0044] In lithium secondary batteries, the liquid electrolyte consists primarily of a lithium salt in a non-aqueous organic solvent, where the liquid electrolyte serves as a conductive path for the movement of cations, i.e., Li + Lithium ions (i.e., Li) pass from the cathode to the anode during discharge. + cations) are used as charge carriers. The dissolution of lithium salts is achieved by + By interaction, i.e., Li + Cation dissolution - (counter)ion interactions are crucial. Thus, many simple lithium salts, such as LiCl, LiF, Li2O, etc., are precluded from electrolyte use because their strong cation-anion interactions result in high lattice energies and thus poor solubility in relevant aprotic solvents. Non-limiting examples of lithium salts include, among others, lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium hexafluoroarsenate (LiAsF6), lithium hexafluoroantimonate (LiSbF6), lithium hexafluorotantalate (LiTaF6), lithium tetrachloroaluminate (LiAlCl4), lithium tetrafluoroborate (LiBF4), lithium chloroborate (Li2B 10 Cl 10 ), lithium fluoroborate (Li2B10 F 10 ), lithium trifluoromethanesulfonate (LiCF3SO3), lithium bis(fluorosulfonyl)imide Li(FSO2)2N (LiFSI), lithium bis(trifluoromethanesulfonyl)imide Li(SO2CF3)2N (LiTFSI), and mixtures thereof.

[0045] Li + Cation conductivity originates from both total ionic conductivity and cation transference number. Given that the cation transference number in non-aqueous organic solvents is low, e.g., typically less than 0.5, ionic conductivity plays a crucial role in battery performance.

[0046] In short, a liquid electrolyte, in which at least one lithium salt is dissolved in at least one non-aqueous organic solvent, plays a vital role as one of the main components of a conventional lithium secondary battery.

[0047] In this regard, recent advances in the field of batteries involve the use of solid materials as electrolyte materials, and sulfide-based solid ionically conductive inorganic particles are particularly promising materials. In such solid-state batteries, the solid electrolyte replaces the function / role of the liquid electrolyte. Much effort has been made to understand the ion transport mechanism in solid electrolytes, but the Li transport mechanism within the solid electrolyte, i.e., between the electrode and electrolyte interfaces (both the electrode / solid electrolyte interface and the active material / solid electrolyte interface in the electrode), is still unclear. + The cation diffusion behavior, however, still lacks a deep understanding.

[0048] Like liquid electrolytes, solid electrolytes are ionic conductors that deliver ions between two electrodes. However, unlike liquid electrolytes, solid electrolytes require the addition of Li to make them conductive. + The lithium cation in lithium argyrodite Li6PS5X (where X = Cl, Br, or I) is, for example, Li + Li as a pathway for cations+ However, the Li in the non-aqueous solvent that constitutes the liquid electrolyte plays a role in the cation diffusion mechanism. + Unlike lithium salts, which dissociate into a cation and the corresponding counteranion, the lithium site in Li6PS5X is thereby + It is understood that the diffusion / transport of cations occurs by forming localized cages where multiple jump processes, i.e., doublet jumps, intracage jumps, and intercage jumps, are possible (Sulfide and oxide inorganic solid electrolytes for All-Solid-State Li Batteries: Nanomaterials 2020, 10, 1606; doi:10.3390 / nano10081606 by Reddy et al.). That is, unlike liquid electrolytes, only one species in solid electrolytes is mobile, and the structure is determined by the mobile species, i.e., Li, which corresponds to the cooperative conduction mechanism. + It has partial site occupancy of cations.

[0049] In view of the above, lithium salts are distinctly different from sulfide-based solid, ionically conductive inorganic particles that contain lithium species within their inorganic structure in that lithium salts need to be dissolved in a solvent to ensure ionic conduction, whereas sulfide-based solid, ionically conductive inorganic particles have intrinsic ionic conductivities of greater than 0.1 mS / cm at room temperature, which are attributed to the sublattice diffusion of mobile lithium species in the inorganic framework.

[0050] In the present invention, the solid composite electrolyte does not contain a lithium salt.

[0051] EP 3940846 A1 (Solvay SA) discloses a solid composite electrolyte comprising at least one polymer, at least one sulfide-based solid, ionically conductive inorganic particle, and at least one lithium salt, which exhibits excellent ionic conductivity.

[0052] In this regard, the solid composite electrolyte according to the present invention differs from the solid composite electrolyte of EP '846 A1 in that the latter comprises at least one sulfide-based solid, ionically conductive inorganic particle and a "conductive polymer," the latter requiring the presence of a lithium salt, whereas the solid composite electrolyte according to the present invention does not require the presence of a lithium salt. It is also believed that there may be two conduction paths for the migration of cations from the cathode to the anode during discharge, i.e., one solid electrolyte and the other so-called (solid) polymer electrolyte. In the latter, cation conduction occurs through interactions with substituents on the polymer chains.

[0053] The solid composite electrolyte of the present invention is characterized by high adhesion properties to current collectors when it is used in fabricating electrodes, such as positive electrodes, of solid state batteries.

[0054] In the present invention, the type of "current collector" depends on whether the electrode provided thereby is a positive electrode or a negative electrode. When the electrode of the present invention is a positive electrode, the current collector typically comprises, and preferably consists of, at least one metal selected from the group consisting of aluminum (Al), nickel (Ni), titanium (Ti), and alloys thereof, preferably Al. When the electrode of the present invention is a negative electrode, the current collector typically comprises, and preferably consists of, at least one metal selected from the group consisting of lithium (Li), sodium (Na), zinc (Zn), magnesium (Mg), copper (Cu), and alloys thereof, preferably Cu.

[0055] A second object of the present invention is a slurry for producing a solid composite electrolyte comprising a) at least one fluoroelastomer, b) at least one sulfide-based solid, ionically conductive inorganic particle different from a lithium salt, and c) at least one non-aqueous solvent, wherein the slurry does not contain a lithium salt.

[0056] Fluoroelastomer is as defined in the present invention.

[0057] c) There are no specific restrictions imposed on the non-aqueous solvent, as long as the non-aqueous solvent a) can dissolve the fluoroelastomer, and b) is compatible with the sulfide-based solid, ionically conductive inorganic particles, and the solvent does not adversely affect the ionic conductivity of the resulting solid composite electrolyte.

[0058] In one embodiment, c) the non-aqueous solvent is selected from the group consisting of nitrile-containing solvents, ethers, esters, thiols, thioethers, ketones, and tertiary amines.

[0059] In a preferred embodiment, the non-aqueous solvent c) is a nitrile-containing solvent having the general formula R-CN, where R represents an alkyl group. Non-limiting examples of nitrile-containing solvents are acetonitrile, butyronitrile, valeronitrile, isobutylnitrile, etc.

[0060] In another preferred embodiment, the non-aqueous solvent c) is an ether having the general formula R1-O-R2 (wherein R1 and R2 independently represent alkyl groups). Ether solvents include cyclic ethers based on 3-, 5-, or 6-membered rings. Cyclic ethers can be substituted with alkyl groups, can have unsaturation, and can have additional functional elements such as nitrogen or oxygen atoms in the ring. Non-limiting examples of (cyclic) ether solvents are diethyl ether, 1,2-dimethoxy ether, cyclopentyl methyl ether, diethyl ether, dibutyl ether, 1,3-dioxolane, anisole, tetrahydrofuran, methyltetrahydrofuran, tetrahydropyran, etc.

[0061] In another preferred embodiment, c) the non-aqueous solvent is an ester having the general formula R-COO-R, where R and R independently represent alkyl groups. Non-limiting examples of ester solvents are butyl butyrate, ethyl benzoate, etc.

[0062] In another preferred embodiment, the non-aqueous solvent c) is a thiol having the general formula R5 = SH or a thioether having the general formula R6-S-R7 (where R5, R6, and R7 are independently alkyl groups). Thioether solvents include cyclic thioethers based on 3-, 5-, or 6-membered rings. Cyclic thioethers can be substituted with alkyl groups, can have unsaturation, and can have additional functional elements such as nitrogen or oxygen atoms in the ring. Non-limiting examples of thiol solvents are ethanethiol, tert-dodecyl mercaptan, thiophenol, tert-butyl mercaptan, octanol thiol, dimethyl sulfide, ethyl methyl sulfide, methyl benzyl sulfide, etc.

[0063] In another preferred embodiment, c) the non-aqueous solvent is a ketone having the general formula R8R9C=O, where R8 and R9 independently represent alkyl groups. Non-limiting examples of ketone solvents are methyl ethyl ketone, methyl isobutyl ketone, di-isobutyl ketone, acetophenone, benzophenone, etc., preferably methyl isobutyl ketone.

[0064] In another preferred embodiment, c) the non-aqueous solvent is R 10 R 11 R 12 N (wherein, R 10 , R 11 and R 12 are independently alkyl groups). The N atom of the tertiary amine can be buried inside a 3-, 5-, or 6-membered ring. Non-limiting examples of tertiary amine solvents are triethylamine, dimethylbutylamine, tributylamine, cyclohexyldimethylamine, N-ethylpiperidine, etc.

[0065] In the present invention, R to R 12The alkyl group refers to an "alkyl group" comprising a saturated hydrocarbon having one or more carbon atoms, including straight-chain alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, etc., cyclic alkyl groups (or "cycloalkyl" or "alicyclic" or "carbocyclic" groups) such as cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl, branched-chain alkyl groups such as isopropyl, tert-butyl, sec-butyl, and isobutyl, and alkyl-substituted alkyl groups such as alkyl-substituted cycloalkyl groups and cycloalkyl-substituted alkyl groups as defined above. Additionally, the alkyl group may contain one or more unsaturated functional groups such as ether, carbonyl, carboxyl, hydroxyl, thio, thiol, thioxy, sulfo, nitrile, nitro, nitroso, azo, amido, imido, amino, imino, or halogen.

[0066] In a preferred embodiment, c) the non-aqueous solvent comprises a nitrile-containing solvent such as acetonitrile; an ether such as tetrahydrofuran, 2-methyl-tetrahydrofuran, 2,5-dimethyl-tetrahydrofuran, 1,3-dioxolane, diethyl ether, and 1,2-dimethoxy ether; an ester such as butyl butyrate; and a ketone such as methyl isobutyl ketone.

[0067] In a more preferred embodiment, c) the non-aqueous solvent is an ester such as butyl butyrate.

[0068] In another more preferred embodiment, c) the non-aqueous solvent is a ketone, such as methyl isobutyl ketone.

[0069] In one embodiment, the slurry may further comprise a second solvent, such as, but not limited to, saturated and aromatic hydrocarbons, including linear and branched alkanes (e.g., heptane), cyclic alkanes (e.g., cyclohexane), and aromatic compounds (e.g., xylene and toluene).

[0070] In the present invention, the slurry can be suitably prepared by a process comprising mixing a) a fluoropolymer, b) sulfide-based solid, ionically conductive inorganic particles, and c) a non-aqueous solvent by any method known to those skilled in the art. In a preferred embodiment, the slurry is prepared by a process comprising a) solubilizing a fluoroelastomer in c) a non-aqueous solvent, followed by adding b) sulfide-based solid, ionically conductive inorganic particles, and mixing the resulting mixture.

[0071] In the present invention, the amount of a) fluoroelastomer in the slurry is such to provide a solid composite electrolyte comprising a) fluoroelastomer in an amount in the range of at least 1.0 wt.%, preferably at least 1.5 wt.%, more preferably 2.0 wt.%, and / or at most 20.0 wt.%, preferably at most 15.0 wt.%, more preferably at most 10.0 wt.%, and most preferably at most 5.0 wt.%, based on the total weight of a) fluoroelastomer and b) sulfide-based solid, ionically conductive inorganic particles.

[0072] In certain embodiments, the amount of a) fluoroelastomer in the slurry is such to provide a solid composite electrolyte comprising a) fluoroelastomer in an amount ranging from 1.0 to 20.0 wt.%, preferably 1.5 to 15.0 wt.%, more preferably 2.0 to 10.0 wt.%, and most preferably 2.0 to 5.0 wt.%, based on the total weight of a) fluoroelastomer and b) sulfide-based solid, ionically conductive inorganic particles. Thus, the resulting solid composite electrolyte exhibits good bonding between a) fluoroelastomer and b) sulfide-based solid, ionically conductive inorganic particles while maintaining good ionic conductivity.

[0073] The slurry according to the present invention is typically applied onto at least one foil of an inert flexible support by a technique selected from casting, spray coating, rotary spray coating, roll coating, doctor blading, slot-die coating, gravure coating, inkjet printing, spin coating, and screen printing. In one embodiment, the wet film thus obtained typically has a thickness of 10 to 400 μm, preferably 50 to 200 μm. The wet film is then dried at a temperature of 10°C to 200°C, preferably 20°C to 80°C. An additional drying step in an oven under vacuum at a temperature of 20°C to 150°C, preferably 50°C to 80°C, can be appropriately carried out to completely remove the solvent. Those skilled in the art can select the optimal duration and temperature of the drying step depending on the boiling point of the solvent. The dried film thus obtained can be further subjected to an additional compression step, such as calendering, uniaxial or isostatic compression, to reduce the porosity and increase the density of the solid composite electrolyte.

[0074] In another embodiment, the slurry may further comprise d) at least one electroactive material, and optionally e) at least one conductive agent.

[0075] In a preferred embodiment, d) the electroactive material is for the positive electrode.

[0076] In the present invention, the term "positive electrode" is intended to mean in particular the electrode of an electrochemical cell where reduction occurs during discharge, while the term "negative electrode" is intended to mean in particular the electrode of an electrochemical cell where oxidation occurs during discharge.

[0077] In the present invention, the term "electroactive material" is intended to mean a material that is capable of incorporating or inserting lithium ions into its structure and subsequently releasing them therefrom during the charging and discharging stages of the battery.

[0078] When forming a positive electrode for a solid-state battery, the electroactive material for the positive electrode is not particularly limited. It may include a composite metal chalcogenide of the formula LiMQ2 (where M is at least one metal selected from transition metals such as Co, Ni, Fe, Mn, Cr, and V, and Q is a chalcogen such as O or S). Among these, it is preferable to use a lithium-based composite metal oxide of the formula LiMO2 (where M is the same as defined above). Preferred examples thereof include LiCoO2, LiNiO2, LiNi x Co 1-x O2 (0 < x < 1), and spinel-structured LiMn2O4 may be mentioned. Another preferred example thereof is a lithium-nickel-manganese-cobalt-based metal oxide of the formula LiNi x Mn y Co z O2 (x + y + z = 1, referred to as NMC), for example, LiNi 1 / 3 Mn 1 / 3 Co 1 / 3 O2, LiNi 0.6 Mn 0.2 Co 0.2 O2, and a lithium-nickel-cobalt-aluminum-based metal oxide of the formula LiNi x Co y Al z O2 (x + y + z = 1, referred to as NCA), for example, LiNi 0.8 Co 0.15 Al 0.05 O2 may be mentioned.

[0079] As an alternative, when forming a positive electrode for a lithium metal battery, further, the electroactive material of the positive electrode is of the formula M1M2(JO4) f E 1-f(Wherein, M1 is lithium which may be partially substituted by another alkali metal representing less than 20% of M1 metal, M2 is a transition metal at a +2 oxidation level selected from Fe, Mn, Ni or a mixture thereof which may be partially substituted by one or more additional metals representing up to 35% of M2 metal and at an oxidation level of +1 to +5 including 0, JO4 is any oxyanion where J is any of P, S, V, Si, Nb, Mo or a combination thereof, E is a fluoride, hydroxide or chloride anion, and f is a molar fraction of the JO4 oxyanion generally included in the range of 0.75 to 1) may include a lithiated or partially lithiated transition metal oxyanion-based electroactive material.

[0080] M1M2(JO4) as defined above f E 1-f The electroactive material is preferably phosphate-based and may have a regular or modified olivine structure.

[0081] More preferably, the electroactive material of the positive electrode has the formula Li 3-x M’ y M” 2-y (JO4)3 (where 0 ≦ x ≦ 3, 0 ≦ y ≦ 2, M’ and M” are the same or different metals, at least one of which is a transition metal, JO4 is preferably PO4 which may be partially substituted by another oxyanion, and J is any of S, V, Si, Nb, Mo or a combination thereof). Even more preferably, the electroactive material is a phosphate-based electroactive material of the formula Li(Fe x Mn 1-x )PO4 (where 0 ≦ x ≦ 1, preferably x = 1), that is, lithium iron phosphate of the formula LiFePO4.

[0082] In a preferred embodiment, the electroactive material of the positive electrode is LiMQ2 (where M is at least one metal selected from Co, Ni, Fe, Mn, Cr and V, and Q is O or S); LiNi x Co 1-x O2 (0 < x < 1); spinel-structured LiMn2O4; the formula LiNix Mn y Co z Lithium-nickel-manganese-cobalt-based metal oxide (NMC) of O2 (x+y+z=1), formula LiNi x Co y Al z O2 (x+y+z=1) is selected from the group consisting of lithium-nickel-cobalt-aluminum-based metal oxides (NCA), lithium-cobalt-based metal oxides (LCO), lithium-nickel-manganese-based metal oxides (LNMO) and LiFePO4.

[0083] In a more preferred embodiment, the electroactive material of the positive electrode is selected from the group consisting of NMC, NCA, LCO, and LNMO.

[0084] In the present invention, the term "conductive agent" is intended to mean a material used to ensure that the electrode has good charge and discharge performance and to provide additional conductivity. Non-limiting examples of conductive agents are carbonaceous materials and metal powders or fibers, such as carbon black, carbon nanotubes (CNTs), vapor-grown carbon fibers (VGCFs), graphite, graphene, graphite fibers, etc. Examples of carbon black include ketjen black and acetylene black. Examples of metal powders or fibers include nickel and aluminum powders or fibers.

[0085] In certain embodiments, the amount of a) fluoroelastomer in the slurry is such to provide a solid composite electrolyte comprising a) fluoroelastomer in an amount ranging from 1.0 to 20.0 wt.%, preferably 1.5 to 15.0 wt.%, more preferably 2.0 to 10.0 wt.%, and most preferably 2.0 to 5.0 wt.%, based on the total weight of a) fluoroelastomer, b) sulfide-based solid ionically conductive inorganic particles, c) electroactive material, and optionally e) at least one conductive agent. Accordingly, the resulting electrode exhibits outstanding adhesion to the current collector.

[0086] A third object of the invention is an electrode comprising a solid composite electrolyte according to the invention, d) at least one electroactive material and, optionally, e) at least one conductive agent.

[0087] In one embodiment, d) the electroactive material is for the positive electrode.

[0088] In one embodiment, the positive electrode comprises a solid composite electrolyte according to the present invention, d) at least one electroactive material, and optionally e) at least one conductive agent.

[0089] In certain embodiments, the positive electrode comprises a) a VDF-CTFE copolymer as the fluoroelastomer, b) Li6PS5Cl as the sulfide-based solid ionically conductive inorganic particles, and d) LiNi as the electroactive material for the positive electrode. 0.6 Mn 0.2 Co 0.2 and optionally e) carbon black as a conductive agent.

[0090] In a more specific embodiment, a) the VDF-CTFE copolymer as a fluoroelastomer comprises repeat units derived from CTFE in an amount of 15.0 to 50.0 mol % (mol % is based on the total moles of repeat units).

[0091] A fourth object of the present invention is a solid-state battery comprising a positive electrode, a negative electrode and a membrane arranged between the positive and negative electrodes, wherein at least one of the positive electrode, the negative electrode and the membrane comprises the solid composite electrolyte according to the present invention, optionally d) at least one electroactive material and / or e) at least one conductive agent.

[0092] In the present invention, the term "membrane" is intended to mean in particular an ion-permeable membrane placed between the positive and negative electrodes, whose function is to block electrons and allow lithium ions to pass through while ensuring physical separation between the electrodes.

[0093] A fifth object of the present invention is a binder solution for solid-state batteries comprising a) at least one fluoroelastomer according to the invention and c) at least one non-aqueous solvent.

[0094] The non-aqueous solvent is as defined in the present invention.

[0095] Those skilled in the art can easily select a) an appropriate amount of non-aqueous solvent to achieve uniform dissolution of the fluoroelastomer and suitable evaporation thereof when the binder solution according to the present invention is used to prepare a solid composite electrolyte, which can be used either as a membrane disposed between a positive electrode and a negative electrode, or as an electrode for a solid-state battery.

[0096] To the extent that the disclosure of any patents, patent applications, and publications incorporated herein by reference conflicts with the statements of this application to the extent that a term may be unclear, the statements of this application shall control.

[0097] The present invention will now be described in more detail with reference to the following examples, the purpose of which is merely illustrative and is not intended to limit the scope of the invention. [Example]

[0098] raw materials - LPSCl (Li6PS5Cl), a crystalline sulfide-based solid ionically conductive inorganic particle, commercially available from NEI; - NMC622 (Cellcore® NMC KHX12), commercially available from Umicore; - conductive carbon black (C-NERGY™ SUPER C65T), commercially available from Imerys; Butyl butyrate (BB), commercially available from Sigma Aldrich; and - Methyl isobutyl ketone (MIBK), commercially available from Sigma Aldrich Fluoroelastomers - Polymer 1: VDF-CTFE (80 / 20 mol%), synthesized in-house at Solvay Specialty Polymers Italy SpA - Polymer 2: VDF-CTFE (70 / 30 mol%), synthesized in-house at Solvay Specialty Polymers Italy SpA Polymer 3: VDF-CTFE (60 / 40 mol%), Voltalef® G150M commercially available from Arkema (T g =-16℃) - Polymer 4: VDF-CTFE (86 / 14 mol%), synthesized in-house at Solvay Specialty Polymers Italy SpA Polymer 5: VDF-HFP (78.5 / 21.5 mol%), commercially available from Tecnoflon® N935 Solvay Specialty Polymers Italy SpA (T g =-19℃).

[0099] Synthesis of polymers 1, 2, and 4 Polymer 1: Into a vertical steel autoclave equipped with baffles and a stirrer operating at 550 rpm, 1.3 L of demineralized water was introduced. The temperature was then brought to the reaction temperature of 75°C, and 3.5 x 10 5 Pa (absolute) of VDF was introduced. A gaseous mixture of VDF / CTFE in a nominal molar ratio of 80 / 20 was introduced at 20.0 × 10 5 The addition was carried out by using a compressor until a pressure of 100 Pa (absolute) was reached.

[0100] The composition of the gaseous mixture present in the autoclave head was analyzed by gas chromatography before the start of the reaction: 83.5 mol% VDF and 16.5 mol% CTFE. Then, 45.0 cc of ammonium persulfate ((NH4)2S2O8) solution in ethyl acetate (3 w / w%) and 2 ml of pure ethyl acetate were fed into the autoclave.

[0101] The polymerization pressure was maintained constant by feeding the monomer mixture, and when 300.0 g of the mixture had been fed, the feed was stopped, the reactor was cooled to room temperature, and then degassed to remove residual, i.e., unreacted, monomers. The as-produced latex was vented and further degassed with nitrogen for 24 hours. The resulting polymer was then isolated using a standard isolation procedure using aluminum sulfate (Al2(SO4)3), and then dried in a vented oven at 90°C for 24 hours.

[0102] Polymer 2: A gaseous mixture of VDF-CTFE at a nominal molar ratio of 70 / 30 was measured at 3.3 × 10 5 Polymer 2 was synthesized similarly to polymer 1, except that VDF was added at 100 Pa (absolute). The composition of the gaseous mixture present in the autoclave head was analyzed by gas chromatography before starting the reaction: 73.8 mol % VDF and 26.2 mol % CTFE.

[0103] Polymer 4: 3.8 × 10 gaseous mixture of VDF-CTFE at a nominal molar ratio of 86 / 14 5 Polymer 4 was synthesized similarly to polymer 1, except that VDF was added at 100 Pa (absolute). The composition of the gaseous mixture present in the autoclave head was analyzed by gas chromatography before starting the reaction: 88.8 mol % VDF and 11.2 mol % CTFE.

[0104] Preparation of solid composite electrolyte Inventive Example 1 (E1) A solid composite electrolyte composed of 95.0 parts by weight (pbw) LPSCI and 5.0 pbw Polymer 1 was prepared in the form of a film as follows.

[0105] A 10.0 wt% polymer solution was prepared by weighing out 1.0 g of Polymer 1 and 9.0 g of BB. Then, 3.705 g of LPSCl, 1.95 g of the 10.0 wt% polymer solution, and 0.345 g of BB were mixed using four glass balls under magnetic stirring at 400 rpm for a minimum of 6 hours. The solids content of the slurry and the casting speed were adjusted to maintain a slurry viscosity of 2.0–10.0 Pa·s throughout the casting process. The resulting slurry was cast onto a flexible support (Kapton® FN) using an automatic film applicator manufactured by Elcometer Ltd. The wet film was dried on a hot plate at 50°C for 1 hour and then placed in an oven at 80°C under vacuum overnight. The sample was stored in a minigrip bag and then placed in a sealed bag. All experiments were performed in an argon-filled glove box.

[0106] Inventive Example 2 (E2) and Inventive Example 3 (E3) Solid composite electrolytes E2 and E3 were prepared similarly to E1, except that polymer 2 and polymer 3 were used instead of polymer 1, respectively.

[0107] Inventive Example 4 (E4) The solid composite electrolyte of E4 was prepared similarly to E1, except that MIBK was used as the solvent instead of BB.

[0108] Comparative example 1 (CE1) CE1 was prepared in the same manner as E1, except that polymer 4 was used instead of polymer 1. For CE1, both BB and MIBK were tried as solvents. However, polymer 4 was not soluble in either BB or MIBK, and as a result, a solid composite electrolyte in the form of a film could not be formed.

[0109] Comparative Example 2 (CE2) The solid composite electrolyte of CE2 was prepared similarly to E1, except that polymer 5 was used instead of polymer 1.

[0110] Comparative Example 3 (CE3) The solid composite electrolyte of CE3 was prepared similarly to CE2, except that MIBK was used as the solvent instead of BB.

[0111] Preparation of the positive electrode Positive electrodes E1-E3 and CE2, composed of 74.0 pbw NMC622, 20.0 pbw LPSCl, 2.0 pbw conductive carbon black, and 4.0 pbw fluoroelastomer (selected from Polymers 1-3 and Polymer 5, respectively), were prepared as follows.

[0112] A 10.0 wt% binder solution was prepared by weighing out 1.0 g of fluoroelastomer and 9.0 g of BB. Then, 1.0 g of LPSCl, 0.1 g of conductive carbon, 3.7 g of NMC622, and 2.0 g of the 10.0 wt% binder solution were mixed using four glass balls under magnetic stirring at 400 rpm for a minimum of 6 hours. The resulting slurry was cast onto an aluminum (Al) current collector using an automatic film applicator manufactured by Elcometer Ltd. The viscosity of the slurry was adjusted to maintain a viscosity of 2.0–10.0 Pa·s and 25.0–30.0 mg / cm throughout the casting process. 2 The solids content of the slurry and the casting speed were adapted to obtain a dry electrode loading of 1000 kJ / cm². The wet films were dried on a hot plate at 50 °C for 1 h, then placed in an oven at 80 °C under vacuum overnight, stored in minigrip bags, and then placed in sealed bags. The experiments were carried out in an argon-filled glove box.

[0113] The positive electrodes of E4 and CE3 were prepared in the same manner as above, except that MIBK was used as the solvent instead of BB.

[0114] Adhesion of positive electrode to Al current collector (peel test) The adhesive strength of the positive electrode to the Al current collector was evaluated using a 180° peel test. An electrode strip (2 cm × 10 cm) of the dried electrode was fixed onto a rigid Al plate (2.6 cm × 10 cm) using double-sided tape (25 mm wide; 0.24 mm thick), with the electrode facing downwards and the current collector facing upwards. The Al current collector was peeled from the electrode using a motorized tension / compression test bench (ESM303, manufactured by Mark-10 Corporation) while maintaining a 180° angle and at a constant speed of 300 mm / min. The force required to remove the Al current collector from the electrode was recorded in Table 1 as the average value of three independent strips produced from three independent electrodes using three independent slurries with the same composition. The peel test was conducted in a dry room with a dew point of -40°C.

[0115] In all the positive electrodes E1 to E4, outstanding adhesion properties to the Al current collector are clearly observed, which can be distinguished from those of CE2 and CE3.

[0116] Bending test of solid composite electrolytes E1, E3 and CE2 Bending tests were carried out to measure the flexibility / elongation properties of the solid composite electrolytes by using a cylindrical mandrel bending tester (Elcometer® 1506), which has a bending lever with a height-adjustable roller and a slide vice to clamp the specimen so that it is bent perfectly and regularly onto the reducing mandrel until the desired effect can be observed.

[0117] The solid composite electrolytes E1, E3, and CE2 in the form of free-standing films were bent onto different cylinders, varying from large to small diameters. The diameter of the first cylinder was observed when cracks began to appear while bending the films onto the cylinders. The results are recorded in Table 1. For the solid composite electrolytes E1 and E3, the first cracks were observed when bending onto a 2 mm diameter cylinder, while those of CE2 began to crack early when they were bent onto a 3 mm diameter cylinder.

[0118] Ionic conductivity of solid composite electrolytes E1, E3, and CE2 The ionic conductivity of the solid composite electrolytes E1, E3, and CE2 in film form was measured by AC impedance spectroscopy using an in-house developed pressure cell, where the film was pressed between two stainless steel electrodes during the impedance measurement. A cross-sectional view of the pressure cell is shown in Figure 1.

[0119] Impedance spectra were measured at a pressure of 370 MPa and a temperature of 20° C. AC impedance measurements were performed with a potentiostat (VMP-300, BioLogic Science Instruments SAS) in the frequency range of 1000 Hz to 4.7 MHz.

[0120] The Nyquist plot of the solid composite electrolyte membrane showed the typical behavior of a solid electrolyte (inorganic, polymer, or composite), with a semicircular and Warburg-type impedance in the high- and low-frequency regions, respectively. The conductive behavior of the composite electrolyte was modeled according to an equivalent circuit R1(R2 / Q2)Q3 (see Figure 2), where R is the resistance and Q is a constant phase element, where R1 and R2 represent the bulk and grain boundary resistances, respectively, and Q2 and Q3 represent the grain boundary and electrode contributions, respectively.

[0121] The intercept of the semicircle with the real axis at high frequencies was attributed to the bulk resistance (R1), and the intercept with the real axis at lower frequencies was attributed to the total resistance of the film (R1 + R2). This total resistance, R, is conventionally used to calculate the conductivity of solid composite electrolytes. Therefore, the ionic conductivity, σ, was obtained using the formula σ = d / (R × A), where d is the thickness of the film and A is the area of the stainless steel electrode. The SI unit of ionic conductivity is siemens per meter (S / m), where S is ohms. -1 and 1 millisiemens per centimeter (mS / cm) is the decimal point of the SI unit, i.e., 1 mS / cm = 0.1 S / m.

[0122]

Table 1

Claims

1. a) with at least one fluoroelastomer; b) At least one sulfide-based solid ion-conducting inorganic particle different from a lithium salt, A solid composite electrolyte containing, a) Fluoroelastomers i) vinylidene difluoride (VDF); and ii) At least one type of C in an amount of 15.0 to 80.0 mol% ２ ~C ８ Chloro and / or bromo and / or iodofluoroolefin (mol% is relative to the total mole of repeating units) Includes repeating units derived from, The solid composite electrolyte does not contain lithium salts. Solid composite electrolyte.

2. ii) C ２ ~C ８ The solid composite electrolyte according to claim 1, wherein chloro and / or bromo and / or iodofluoroolefin constitutes 15.0 to 65.0 mol%, preferably 15.0 to 50.0 mol% (mol% is relative to the total moles of repeating units).

3. ii) C ２ ~C ８ The solid composite electrolyte according to claim 1, wherein the chloro and / or bromo and / or iodofluoroolefin is selected from the group consisting of 1,1-chlorofluoroethylene (CFE), chlorodifluoroethylene (CDFE), bromotrifluoroethylene, chlorotrifluoroethylene (CTFE), 1,2-dichloro-1,2-difluoroethylene, iodotrifluoroethylene, and combinations thereof.

4. a) The fluoroelastomer is at least one C different from iii)i) and ii). ２ ~C ８ The solid composite electrolyte according to claim 1, further comprising repeating units derived from fluoroolefins.

5. iii) C ２ to C ８ The fluorinated olefin is selected from the group consisting of vinyl fluoride (VF), trifluoroethylene (TrFE), tetrafluoroethylene (TFE), hexafluoropropylene (HFP), hexafluoroisobutylene, and combinations thereof, the solid composite electrolyte according to claim 4.

6. a) The solid composite electrolyte according to claim 1, wherein the fluoroelastomer has a heat of fusion of less than 5.0 J / g, preferably less than 3.0 J / g, and more preferably less than 2.0 J / g, as measured according to ASTM D3418.

7. b) Sulfide-based solid ion-conducting inorganic particles are - Li １０ SnP ２ S １２ Lithium tin sulfide ("LSPS") materials such as: - Equation (Li ２ S) ｘ - (P ２ S ５ ) ｙ (In the equation, x + y = 1 and 0 ≤ x ≤ 1), Li ７ P ３ S １１ Li ７ PS ６ Li ４ P ２ S ６ Li ９．６ P ３ S １２ and Li ３ PS ４ Lithium phosphate ("LPS") materials such as glass, crystalline, or glass-ceramic; - Li ２ CuPS ４ LiLi １＋２ｘ Zn １－ｘ PS ４ (in the formula, 0≦x≦1), Li ３．３３ Mg ０．３３ P ２ S ６ , and Li ４－３ｘ Sc ｘ P ２ S ６ Doped LPS (where 0 ≤ x ≤ 1 in the formula); - Lithium phosphorus sulfide oxygen ("LPSO") material of formula LixPySzO (where 0.33 ≤ x ≤ 0.67, 0.07 ≤ y ≤ 0.2, 0.4 ≤ z ≤ 0.55, 0 ≤ w ≤ 0.15); - Li １０ GeP ２ S １２ and Li １０ SiP ２ S １２ Lithium phosphide materials containing X such as Si, Ge, Sn, As, and Al ("LXPS"); - Lithium phosphate oxygen ("LXPSO") containing X, where X is Si, Ge, Sn, As, or Al; - Lithium silicon sulfide ("LSS") materials; - Li ３ BS ３ and Li ２ S-B ２ S ３ - Lithium boron sulfide materials such as LiI; - Li ０．８ Sn ０．８ S ２ Li ４ SnS ４ Li ３．８３３ Sn ０．８３３ As ０．１６６ S ４ Li ３ AsS ４ -Li ４ SnS ４ , Li substitution for Ge ３ AsS ４ Lithium tin sulfide materials and lithium arsenide materials, as well as - General formula Li ａ PS ｂ X ｃ Lithium phosphorus sulfide material (wherein X represents at least one halogen element selected from the group of Cl, Br and I or combinations thereof; a represents a number from 2.0 to 7.0, b represents a number from 3.5 to 6.0, and c represents a number from 0 to 3.0) A solid composite electrolyte according to claim 1, selected from the group consisting of the following.

8. A slurry for producing a solid composite electrolyte according to any one of claims 1 to 7, comprising a) at least one fluoroelastomer, b) at least one sulfide-based solid ion-conducting inorganic particle different from a lithium salt, and c) at least one non-aqueous solvent, wherein the slurry does not contain a lithium salt.

9. c) The slurry according to claim 8, wherein the non-aqueous solvent is selected from the group consisting of nitrile-containing solvents, ethers, esters, thiols, thioethers, ketones, tertiary amines, and cyclic carbonate esters, preferably butyl butyrate and / or methyl isobutyl ketone.

10. d) the slurry according to claim 8, further comprising at least one electroactive material and optionally e) at least one conductive agent.

11. d) The electroactive material is for the positive electrode and is of the formula LiNi ｘ Mn ｙ Co ｚ O ２ Lithium-nickel-manganese-cobalt based metal oxide with (x + y + z = 1), formula LiNi ｘ Co ｙ Al ｚ O ２ The slurry according to claim 10, selected from the group consisting of lithium-nickel-cobalt-aluminum based metal oxides, lithium-cobalt based metal oxides, and lithium-nickel-manganese based metal oxides of (x + y + z = 1).

12. An electrode comprising a solid composite electrolyte according to any one of claims 1 to 7, d) at least one electroactive material, and optionally e) at least one conductive agent.

13. d) The electroactive material is for the positive electrode and is of the formula LiNi ｘ Mn ｙ Co ｚ O ２ Lithium-nickel-manganese-cobalt based metal oxide with (x + y + z = 1), formula LiNi ｘ Co ｙ Al ｚ O ２ The electrode according to claim 12, selected from the group consisting of a lithium-nickel-cobalt-aluminum-based metal oxide, a lithium-cobalt-based metal oxide, and a lithium-nickel-manganese-based metal oxide with (x + y + z = 1).

14. A solid-state battery comprising a positive electrode, a negative electrode, and a membrane disposed between the positive electrode and the negative electrode, wherein at least one of the positive electrode, the negative electrode, and the membrane comprises a solid composite electrolyte according to any one of claims 1 to 7, and optionally further comprises d) at least one electroactive material and / or e) at least one conductive agent.

15. a) A binder solution for a solid battery comprising at least one fluoroelastomer and c) at least one non-aqueous solvent, wherein a) the fluoroelastomer is i) vinylidene difluoride (VDF); and ii) At least one C of 15.0 to 80.0 mol% ２ to C ８ chloro and / or bromo and / or iodo fluoroolefin (mol% is based on the total mol of the repeating unit) A binder solution containing repeating units derived from [a specific source].

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