Structures, composites, batteries, and methods for manufacturing composites

Abstract

The present invention provides a novel structure and composite suitable for a battery, and a battery including such a structure or composite. A structure characterized by having an electrode layer, an inorganic solid electrolyte layer, and a fluoropolymer layer provided between the electrode layer and the inorganic solid electrolyte layer, wherein the fluoropolymer layer is composed of a composite including a fluoropolymer and an alkali metal salt.

Description

Technical Field

[0001] The present invention relates to a structure, a composite, a battery, and a method for manufacturing the composite. Background Art

[0002] In recent years, solid electrolytes that exhibit high ionic conductivity comparable to non-aqueous electrolytes have been developed, and the development towards practical use of all-solid-state batteries has been accelerated.

[0003] Patent Document 1 describes an electrolyte membrane obtained by casting a mixture of succinonitrile, polyethylene oxide, polyethylene glycol dimethacrylate, lithium bis(trifluoromethanesulfonyl)imide, and an ultraviolet (UV) initiator on a glass plate and then polymerizing it by ultraviolet irradiation.

[0004] Patent Document 2 describes a polymer electrolyte that contains segments such as perfluoropolyether (PFPE), segments such as poly(ethylene oxide) (PEO), and a lithium salt.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2013-532360

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2018-522085 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] An object of the present invention is to provide a novel structure and composite suitable for a battery, and a battery including such a structure or composite.

[0011] Means for Solving the Problems

[0012] The present invention relates to a structure, characterized in that

[0013] the structure has an electrode layer, an inorganic solid electrolyte layer, and a fluorine-containing polymer layer provided between the electrode layer and the inorganic solid electrolyte layer,

[0014] the fluorine-containing polymer layer is composed of a composite containing a fluorine-containing polymer and an alkali metal salt.

[0015] The fluorine-containing polymer preferably contains heteroatoms other than fluorine atoms and fluorine atoms on the main chain.

[0016] The composite preferably further contains an organic heterogeneous crystal.

[0017] The present invention relates to a composite, characterized in that it comprises a fluoropolymer and an alkali metal salt, and the fluoropolymer comprises the formula:

[0018] -[CR 1 R 2 -CR 3 R 4 -

[0019] (In the formula, R 1 ~R 4 are independently H, F, Cl, CF 3 , OR 11 (R 11 is an organic group having 1 to 8 carbon atoms). Among them, at least one of R 1 ~R 4 is F) the structural unit (1) represented by, and

[0020] Formula:

[0021] -[CR 5 R 6 -CR 7 R 8 -

[0022] (In the formula, R 5 ~R 8 are independently H, an alkyl group having 1 to 3 carbon atoms, a functional group containing a heteroatom other than a fluorine atom, or a group containing the above functional group. Among them, at least one of R 5 ~R 8 is a functional group containing a heteroatom other than a fluorine atom or a group containing the above functional group) the structural unit (2) represented by, and does not contain the formula: -(R a O) m -(R a is a perfluoroalkylene group, and m is an integer of 2 or more) the structure represented by.

[0023] The above functional group containing a heteroatom other than a fluorine atom is preferably at least one selected from the group consisting of a hydroxyl group, an amide group, a carbonate group, and an ester group.

[0024] The above structural unit (1) is preferably a structural unit based on at least one selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, vinylidene fluoride, perfluoro(methyl vinyl ether), and perfluoro(propyl vinyl ether).

[0025] Preferably, the above structural unit (1) is a structural unit based on at least one selected from the group consisting of tetrafluoroethylene and hexafluoropropylene,

[0026] The above structural unit (2) is based on formula (i):

[0027] [Chemical formula 1]

[0028]

[0029] (In the formula, R 1 and R 2 are independently H or an alkyl group having 1 to 10 carbon atoms) represents a structural unit of a compound.

[0030] The composite of the present invention preferably further contains an organic heterogeneous crystal.

[0031] The above-mentioned organic heterogeneous crystal is preferably a soft and viscous crystal or a molecular crystal containing a heteroatom and a carbon atom.

[0032] The composite of the present invention is preferably used in an electrolyte.

[0033] The present invention also relates to a battery including the structure or the composite of the present invention.

[0034] The above-mentioned battery is preferably an all-solid-state battery.

[0035] The present invention also relates to a method for manufacturing a composite, which is characterized in that it includes step (1) and step (2).

[0036] Step (1) is a step of obtaining a mixture by mixing a fluoropolymer, an alkali metal salt, and a solvent. The fluoropolymer contains the formula:

[0037] -[CR 1 R 2 -CR 3 R 4 -

[0038] (In the formula, R 1 to R 4 are independently H, F, Cl, CF 3 , OR 11 (R 11 is an organic group having 1 to 8 carbon atoms). Among them, at least one of R 1 to R 4 is F) represents a structural unit (1), and

[0039] The formula:

[0040] -[CR 5 R 6 -CR 7 R 8 -

[0041] (In the formula, R 5 to R 8Each independently represents H, an alkyl group having 1 to 3 carbon atoms, a functional group containing a heteroatom other than a fluorine atom, or a group containing the above functional group. Among them, R 5 ~R 8 At least one of them is a structural unit (2) represented by a functional group containing a heteroatom other than a fluorine atom or a group containing the above functional group), and does not contain the formula: -(R a O) m -(R a is a perfluoroalkylene group, and m is an integer of 2 or more);

[0042] Step (2) is a step of obtaining a complex containing the above fluoropolymer and the above alkali metal salt by removing the above solvent from the above mixture.

[0043] The above manufacturing method preferably further includes a step (3) of coating the above mixture obtained in step (1) onto an object.

[0044] Effects of the Invention

[0045] According to the present invention, a novel structure and complex suitable for a battery, and a battery having such a structure or complex can be provided. Description of the Drawings

[0046] Figure 1 is a graph showing the results of LSV (Linear Sweep Voltammetry) measurements in Example 5 and Comparative Example 3. Detailed Description

[0047] The present invention will be specifically described below.

[0048] The present invention relates to a structure characterized by having an electrode layer, an inorganic solid electrolyte layer, and a fluoropolymer layer provided between the above electrode layer and the above inorganic solid electrolyte layer, and the above fluoropolymer layer is composed of a complex containing a fluoropolymer and an alkali metal salt.

[0049] The structure of the present invention can exhibit excellent ionic conductivity and withstand voltage.

[0050] In an electrochemical device such as an all-solid-state battery, when an inorganic solid electrolyte is used as a constituent material of an electrode layer or an electrolyte layer, there is a problem that voids are likely to be generated between particles and the ionic conductivity is likely to decrease.

[0051] In the structure of the present invention, since a specific fluorine-containing polymer layer is provided between the electrode layer and the inorganic solid electrolyte layer, voids are not easily generated between the electrode layer (e.g., particles containing an electrode active material or an inorganic solid electrolyte) and the inorganic solid electrolyte layer, and excellent ionic conductivity, for example, excellent alkali metal ion conductivity can be exhibited.

[0052] In addition, by using a fluorine-containing polymer, excellent withstand voltage properties can be exhibited.

[0053] As described below, the structure of the present invention can be suitably used as a constituent material of a battery.

[0054] The above-mentioned fluorine-containing polymer layer is composed of a composite (hereinafter also referred to as composite (1)) containing a fluorine-containing polymer and an alkali metal salt.

[0055] As the above-mentioned fluorine-containing polymer, polymers having fluorine atoms can be widely used. For example, fluorine-containing polymers containing heteroatoms other than fluorine atoms and fluorine atoms on the main chain (hereinafter also referred to as fluorine-containing polymer (1)); tetrafluoroethylene [TFE] / perfluoro(alkyl vinyl ether) [PAVE] copolymer [PFA], TFE / hexafluoropropylene [HFP] copolymer [FEP], ethylene [Et] / TFE copolymer [ETFE], Et / TFE / HFP copolymer [EFEP], polychlorotrifluoroethylene [PCTFE], chlorotrifluoroethylene [CTFE] / TFE copolymer, Et / CTFE copolymer, polyvinyl fluoride [PVF], polyvinylidene fluoride [PVdF], vinylidene fluoride [VdF] / TFE copolymer, VdF / HFP copolymer, VdF / TFE / HFP copolymer, VdF / HFP / (meth)acrylic acid copolymer, VdF / CTFE copolymer, VdF / pentafluoropropylene copolymer, VdF / PAVE / TFE copolymer, etc., fluororesins other than fluorine-containing polymer (1); vinylidene fluoride [VdF]-based fluororubbers, tetrafluoroethylene [TFE] / propylene [Pr]-based fluororubbers, TFE / Pr / VdF-based fluororubbers, ethylene [Et] / hexafluoropropylene [HFP]-based fluororubbers, Et / HFP / VdF-based fluororubbers, Et / HFP / TFE-based fluororubbers, perfluororubbers, fluorosilicone-based fluororubbers, fluorophosphazene-based fluororubbers, etc., fluororubbers other than fluorine-containing polymer (1); and so on. One or more of these can be used.

[0056] The above-mentioned fluorine-containing polymer (1) contains fluorine atoms on the main chain. As long as it contains fluorine atoms on the main chain, it may also have fluorine atoms in parts other than the main chain.

[0057] The above-mentioned fluorine-containing polymer (1) contains heteroatoms other than fluorine atoms. In the above-mentioned fluorine-containing polymer (1), the above-mentioned heteroatoms may be present on the main chain or on the side chain, and are preferably present on the side chain.

[0058] The hetero atom may be any hetero atom other than a fluorine atom, preferably a hetero atom other than a halogen atom, more preferably two or more hetero atoms selected from the group consisting of an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, a boron atom and a phosphorus atom, further preferably two or more hetero atoms selected from the group consisting of an oxygen atom, a nitrogen atom, a sulfur atom and a silicon atom, and particularly preferably two or more hetero atoms selected from the group consisting of an oxygen atom and a nitrogen atom.

[0059] It should be noted that “two or less kinds” means one or two kinds.

[0060] The fluorinated polymer (1) preferably has a functional group containing a hetero atom other than a fluorine atom. Examples of the hetero atom contained in the functional group include the above-mentioned hetero atoms.

[0061] Examples of the functional group include a hydroxyl group (excluding the hydroxyl group in the carboxyl group. The same shall apply hereinafter), a carboxyl group, a carbamate group, an amide group, a carbonyl group, a carbonate group, an ester group, an ether group, an amino group, an isocyanate group, a group represented by -COOCO-, a mercapto group, a silyl group, a silicate group, an epoxy group, and a cyano group.

[0062] As the above-mentioned functional group, it is preferably at least one selected from the group consisting of a hydroxyl group, an amide group, a carbonate group, an ether group and an ester group, more preferably at least one selected from the group consisting of a hydroxyl group, an amide group, a carbonate group and an ester group, and further preferably at least one selected from the group consisting of a hydroxyl group, an amide group and an ester group.

[0063] The above-mentioned fluorine-containing polymer (1) preferably does not contain the formula: -(R a O) m -(R a is a structure represented by a perfluoroalkylene group, and m is an integer greater than or equal to 2).

[0064] In addition, the fluorinated polymer (1) preferably does not contain a group consisting of the following formula: -(R b O) n -(R b is a structure represented by a non-fluorinated alkylene group, and n is an integer greater than or equal to 1).

[0065] The fluorinated polymer (1) preferably has a structural unit based on a fluorinated monomer and a structural unit based on a monomer having a functional group containing a hetero atom other than a fluorine atom (hereinafter also referred to as a hetero group-containing monomer).

[0066] Examples of the fluorinated monomer and the hetero group-containing monomer include fluorinated monomers and hetero group-containing monomers that can be used in the fluorinated polymer (2) described later.

[0067] As the fluoropolymer (1) described above, the fluoropolymer (2) described below is preferred.

[0068] The above PVdF can be a homopolymer of VdF or a copolymer of VdF and a trace amount of comonomer. As the above comonomer, vinyl fluoride, fluoroalkyl vinyl ether, (perfluoroalkyl)ethylene, hexafluoropropene, 2,3,3,3-tetrafluoropropene, trans-1,3,3,3-tetrafluoropropene, ethylene, propylene, etc. can be cited.

[0069] When the above PVdF is a copolymer of VdF and the above comonomer, the content of the polymerization unit based on the above comonomer is preferably 5 mol% or less, more preferably 3 mol% or less, further preferably 2 mol% or less, and particularly preferably 1 mol% or less with respect to all polymerization units. The lower limit of the content of the polymerization unit based on the above comonomer can be 0.01 mol%.

[0070] The melting point of the fluororesin other than the above fluoropolymer (1) is preferably 100 to 360 °C, more preferably 140 to 350 °C, and further preferably 160 to 320 °C.

[0071] The melting point is the temperature corresponding to the maximum value in the heat of fusion curve when the temperature is raised at a rate of 10 °C / min using a differential scanning calorimeter [DSC].

[0072] The Mooney viscosity of the above fluororubber at 100 °C is preferably 2 to 200, more preferably 10 to 150, and further preferably 30 to 80 or less.

[0073] The Mooney viscosity is measured according to ASTM D1646 and JIS K6300.

[0074] As the above fluoropolymer, a fluoropolymer capable of dissolving the above alkali metal salt is preferred.

[0075] As the above fluoropolymer, at least one selected from the group consisting of the fluoropolymer (1) and fluororesins other than the fluoropolymer (1) is preferred, and the fluoropolymer (1) is more preferred.

[0076] As the above alkali metal salt, fluorides, chlorides, bromides, sulfates, nitrates, sulfides, hydrides, nitrides, phosphides, sulfonimide salts, trifluoromethanesulfonates, thiocyanates, perchlorates, borates, selenides, fluorophosphates, fluorosulfonates, amidosulfonates, etc. of alkali metals such as lithium, sodium, and potassium can be cited, but are not limited to these.

[0077] As the above alkali metal salt, specifically, LiSCN, LiN(CN) 2 , LiClO 4 , LiBF 4, LiAsF 6 , LiPF 6 , LiCF 3 SO 3 , Li(CF 3 SO 2 ) 2 , Li(CF 3 SO 2 ) 3 , LiN(SO 2 C 2 F 5 ) 2 , lithium fluoroalkyl phosphate salts, lithium oxalate borate salts, other bis(chelating) lithium borate salts having 5-7 membered rings, lithium bis(trifluoromethanesulfonylimide) (LiTFSI), lithium bis(monofluoromethanesulfonylimide) (LiFSI), LiCl, LiF, LiBr, LiI, LiPF 3 (C 2 F 5 ) 3 , LiPF 3 (CF 3 ) 3 , LiB(C 2 O 4 ) 2 , lithium difluorooxalate borate (LiDFOB), LiPO 2 F 2 , LiSO 3 F, (CH 3 CH 2 ) 2 NSO 3 Li, (CH 2 =CHCH 2 ) 2 NSO 3 , (CF 3 CH 2 ) 2 NSO 3 , (CF 3 CH 2 )N(CH 3 )SO 3 , (N≡CCH 2 ) 2 NSO 3 Li, lithium salts such as pyrrolidin-1-yl sulfonate, piperidin-1-yl sulfonate, morpholin-4-yl sulfonate; NaSCN, NaSO 3 CF 3, sodium salts such as NaCl, NaF, NaBr, NaI, NaFSI, NaTFSI, etc.; potassium salts such as KCl, KF, KBr, KI, KFSI, KTFSI, etc.; mixtures thereof, etc.

[0078] As the above alkali metal salts, LiSCN, LiN(CN) is preferred 2 , LiClO 4 , LiBF 4 , LiAsF 6 , LiPF 6 , LiCF 3 SO 3 , Li(CF 3 SO 2 ) 2 , Li(CF 3 SO 2 ) 3 , LiN(SO 2 C 2 F 5 ) 2 , LiTFSI, LiFSI, LiCl, LiF, LiBr, LiI, LiPO 2 F 2 , LiSO 3 F, (CH 3 CH 2 ) 2 NSO 3 , (CH 2 =CHCH 2 ) 2 NSO 3 , (CF 3 CH 2 ) 2 NSO 3 , (CF 3 CH 2 )N(CH 3 )SO 3 , (N≡CCH 2 ) 2 NSO 3 Li, lithium pyrrolidine-1-sulfonate, lithium piperidine-1-sulfonate, lithium morpholine-4-sulfonate, more preferably LiTFSI, LiFSI, LiCl, LiF, LiBr, LiI, LiPO 2 F 2 , LiSO 3 F, (CH 3 CH 2 ) 2 NSO 3 , (CH 2=CHCH 2 ) 2 NSO 3 Li, particularly preferably LiTFSI, LiFSI, LiI, LiPO 2 F 2 、LiSO 3 F、(CH 3 CH 2 ) 2 NSO 3 Li、(CH 2 =CHCH 2 ) 2 NSO 3 Li.

[0079] The above alkali metal salt is preferably dissolved in the above fluoropolymer (1). Thereby, the ionic conductivity is further improved.

[0080] The content of the above alkali metal salt is preferably 0.1 to 500 parts by mass, more preferably 1 to 100 parts by mass, and still more preferably 10 to 50 parts by mass with respect to 100 parts by mass of the above fluoropolymer (1).

[0081] The above complex (1) preferably further contains an organic heterogeneous system crystal. Thereby, the ionic conductivity is further improved. As the above organic heterogeneous system crystal, an organic heterogeneous system crystal that can be used for the complex of the present invention described later can be cited.

[0082] The content of the above organic heterogeneous system crystal is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 50 parts by mass with respect to 100 parts by mass of the above fluoropolymer (1).

[0083] The above complex (1) can be manufactured according to the manufacturing method of the present invention described later.

[0084] The above electrode layer preferably contains an electrode active material and an inorganic solid electrolyte.

[0085] As the above electrode active material, a positive electrode active material and a negative electrode active material can be cited according to the positive and negative of the electrode.

[0086] As the above positive electrode active material, a component used as a positive electrode active material in an all-solid-state battery can be used without particular limitation.

[0087] For example, it can be cited: lithium cobaltate (LiCoO 2 ), lithium nickelate (LiNiO 2 ), lithium manganate (LiMn 2 O 4 ), LiNiCoO 2 , lithium nickel cobalt manganate (LiCo 1 / 3 Ni1 / 3 Mn 1 / 3 O 2 etc.), lithium nickel cobaltate containing aluminum (LiNi 0.8 Co 0.15 Al 0.05 O 2 etc.), Li 1+x Mn 2-x-y M y O 4 (M is one or more metal elements selected from Al, Mg, Co, Fe, Ni, and Zn) represents a heterogeneous element-substituted Li-Mn spinel, lithium titanate (Li x TiO y ), lithium metal phosphate (LiMPO 4 , M is Fe, Mn, Co, or Ni), transition metal oxides (V 2 O 5 , MoO 3 etc.), sulfur-containing compounds (Li 2 S, TiS 2 etc.), lithium silicon oxide (Li x Si y O z ), lithium metal (Li), lithium alloy (LiM, M is Sn, Si, Al, Ge, Sb, or P), lithium storage intermetallic compound (Mg x M or L y Sb, M is Sn, Ge, or Sb, L is In, Cu, or Mn), Li-excessive composite oxide (Li 2 MnO 3 -LiMO 2 ), Li 2 PtO 3 , LiNiVO 4 , LiCoVO 4 , LiCrMnO 4 , LiFe(SO 4 ) 3 etc. lithium-containing compounds; Na 4 M 3 (PO 4 ) 2 P 2 O 7 (M is Ni, Co, or Mn) and other sodium-containing compounds; their derivatives.

[0088] The particle size of the above positive electrode active material is not particularly limited, and a material with an average particle size of 3 to 20 μm can be appropriately used.

[0089] As the above-mentioned negative electrode active material, a component used as a negative electrode active material in an all-solid-state battery can be used without particular limitation.

[0090] For example, in addition to carbonaceous materials capable of inserting and extracting alkali metal ions, single substances, alloys, compounds, etc. of metals or semi-metals capable of inserting and extracting alkali metal ions can also be cited. As the carbonaceous material, graphite (natural graphite, artificial graphite, etc.), hard carbon, amorphous carbon, etc. can be exemplified. As the single substance, alloy of metal or semi-metal, lithium metal and alloy can be cited; metal powders such as Sn, Si, Al, Sb, Zn, Bi, etc.; Sn 5 Cu 6 、Sn 2 Co、Sn 2 Fe、Ti-Sn、Ti-Si and other metal alloy powders; other amorphous alloys, plated alloys, etc. As the above-mentioned compounds, for example, oxides, sulfides, nitrides, hydrides, silicides (lithium silicide, etc.) can be cited. As the oxide, titanium oxide, lithium titanium oxide (Li 4 / 3 Ti 5 / 3 O, etc.), silicon oxide, etc. can be cited. As the nitride, lithium cobalt nitride (LiCoN) etc. can be cited. The negative electrode active material can be used alone or in combination of two or more kinds. For example, silicon oxide and carbonaceous material can be used in combination.

[0091] The particle size of the above-mentioned negative electrode active material is not particularly limited, and a material with an average particle size of 3 to 80 μm can be appropriately used.

[0092] As the above-mentioned inorganic solid electrolyte, the same inorganic solid electrolyte as the inorganic solid electrolyte described later that can be used in the above-mentioned inorganic solid electrolyte layer can be used.

[0093] The above electrode layer may further contain a binder and a conductive aid.

[0094] As the above-mentioned binder, for example, the above-mentioned composite (1), polysiloxane, polyalkylene glycol, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride, hydrogenated butene rubber, polysulfide rubber, styrene-butadiene rubber (SBR), styrene-butadiene rubber / carboxymethyl cellulose (SBR / CMC), polyethylene oxide (PEO), branched PEO, polyphenylene ether (PPO), PEO-PPO copolymer, branched PEO-PPO copolymer, alkyl boron-containing polyether, etc. can be cited.

[0095] There is no particular limitation on the above-mentioned conductive aid, and materials used in the past can be used, such as graphite, carbon black, etc.

[0096] The above electrode layer may further have an electrode current collector. As the above electrode current collector, any electrode current collector that can be used as an electrode current collector for an all-solid-state battery can be used without particular limitation. As the form of such an electrode current collector, for example, a foil-like body, a plate-like body, a net-like body, an aggregate of powders, etc. can be cited, and a form obtained by forming a film of the material of the electrode current collector can be used. The foil-like body can be an electrolytic foil, an etched foil, etc.

[0097] As the material of the above electrode current collector, for example, aluminum, magnesium, stainless steel, titanium, iron, cobalt, zinc, tin, copper, nickel, germanium, indium, their alloys, carbon, etc. can be cited.

[0098] The thickness of the above electrode layer can be, for example, 50 to 500 μm.

[0099] The above electrode layer can be manufactured, for example, by the following method: mixing the above inorganic solid electrolyte, the above electrode active material, and other components if necessary with a solvent, coating the obtained mixed solution onto a substrate (for example, the above electrode current collector), and drying to manufacture the above electrode layer. Pressing can also be further performed as needed.

[0100] In addition to the above method, a sandblasting method, an aerosol deposition method, a cold spray method, a sputtering method, a vapor growth method, a pressure pressing method, a spraying method, etc. can also be used.

[0101] As the solvent used in the manufacture of the above electrode layer, an organic solvent is preferred. As the above organic solvent, for example, hydrocarbon-based organic solvents such as hexane, heptane, toluene, xylene, and decalin can be cited. The above organic solvent preferably uses a component with a reduced water content through dehydration treatment.

[0102] As the inorganic solid electrolyte constituting the above inorganic solid electrolyte layer, a sulfide-based solid electrolyte and an oxide-based solid electrolyte can be cited.

[0103] As the above sulfide-based solid electrolyte, as long as it contains a sulfur component, there is no particular limitation, and a material that can be applied as a sulfide-based solid electrolyte for an all-solid-state battery can be used.

[0104] As the above sulfide-based solid electrolyte, for example, Li 2 S-SiS 2 、Li 2 S-P 2 S 5 、Li 2 S-GeS 2 、Li 2 S-B 2 S 3 、Li 2 S-Ga 2 S3 , Li 2 S-Al 2 S 3 , Li 2 S-GeS 2 -P 2 S 5 , Li 2 S-Al 2 S 3 -P 2 S 5 , Li 2 S-P 2 S 3 , Li 2 S-P 2 S 3 -P 2 S 5 , LiX 0 -Li 2 S-P 2 S 5 , LiX 0 -Li 2 S-SiS 2 , LiX 0 -Li 2 S-B 2 S 3 , Li 3 PO 4 -Li 2 S-Si 2 S, Li 3 PO 4 -Li 2 S-SiS 2 , LiPO 4 -Li 2 S-SiS, LiX 0 -Li 2 S-P 2 O 5 , LiX 0 -Li 3 PO 4 -P 2 S 5 and other lithium ion conductors (X 0 is I, Br or Cl).

[0105] The above sulfide solid electrolyte can be crystalline, amorphous, or glass-ceramic.

[0106] As the above oxide-based solid electrolyte, a material that can be used as an oxide-based solid electrolyte for all-solid-state batteries can be used.

[0107] As the above-mentioned oxide-based solid electrolyte, for example, LiPON, Li 3 PO 4 、Li 2 SiO 2 、Li 2 SiO 4 、Li 0.5 La 0.5 TiO 3 、Li 1.3 Al 0.3 Ti 0.7 (PO 4 ) 3 、La 0.51 Li 0.34 TiO 0.74 、Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 can be mentioned.

[0108] The above-mentioned oxide solid electrolyte can be crystalline, amorphous, or glass-ceramic.

[0109] The above-mentioned inorganic solid electrolyte layer can further contain a binder. As the above-mentioned binder, for example, the above-mentioned complex (1), polysiloxane, polyalkylene glycol, polyethylene, polypropylene, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), tetrafluoroethylene-hexafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-trifluorochloroethylene copolymer, ethylene-tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), vinylidene fluoride-pentafluoropropylene copolymer, propylene-tetrafluoroethylene copolymer, ethylene-trifluorochloroethylene copolymer (ECTFE), vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, vinylidene fluoride-perfluoromethyl vinyl ether-tetrafluoroethylene copolymer, ethylene-(meth)acrylic acid copolymer or its (Na + ) ion cross-linked body, ethylene-(meth)acrylic acid methyl ester copolymer or its (Na + ) ion cross-linked body, etc. can be mentioned.

[0110] The above-mentioned inorganic solid electrolyte layer can be manufactured, for example, by the following method: mixing the above-mentioned inorganic solid electrolyte and other necessary components with a solvent, coating the obtained mixed solution onto a substrate, and drying it to manufacture the above-mentioned electrolyte layer. Pressing can also be further performed as needed.

[0111] In addition to the above methods, sandblasting, aerosol deposition, cold spraying, sputtering, vapor growth, pressure pressing, spraying, etc. can also be used.

[0112] As the solvent used in the production of the above inorganic solid electrolyte layer, an organic solvent is preferred. As the above organic solvent, for example, heptane, toluene, hexane, tetrahydrofuran (THF), methyl isobutyl ketone (MIBK), N-methylpyrrolidone, acetonitrile, dimethoxyethane, dimethyl carbonate, etc. can be cited. The above organic solvent preferably uses a component in which the water content is reduced by dehydration treatment.

[0113] In the structure of the present invention, it is preferable that at least a part of the above complex (1) constituting the above fluoropolymer layer is impregnated in the voids (for example, the voids between the particles of the inorganic solid electrolyte) of at least a part of the above inorganic solid electrolyte layer.

[0114] In addition, it is preferable that at least a part of the above complex (1) is impregnated in the voids (for example, the voids between the particles of the electrode active material or the inorganic solid electrolyte) of at least a part of the above electrode layer.

[0115] The structure of the present invention can be produced, for example, by sequentially laminating the above electrode layer, the above fluoropolymer layer, and the above inorganic solid electrolyte layer and pressing as required.

[0116] Alternatively, it can be produced as follows: A raw material mixture of the above fluoropolymer layer (the above complex (1)) is coated on the above electrode layer or the above inorganic solid electrolyte layer, the solvent is removed, and then the above inorganic solid electrolyte layer or the above electrode layer is laminated on the formed fluoropolymer layer, and pressing is performed as required, thereby producing.

[0117] The structure of the present invention can be used in fields requiring ion conductivity and voltage resistance, and can be suitably used, for example, as a constituent material of a battery, particularly a secondary battery. Among them, it can be suitably used as a constituent material of an all-solid-state battery, particularly an all-solid-state secondary battery.

[0118] The present invention also relates to a complex (hereinafter also referred to as complex (2)), which is characterized in that it contains a fluoropolymer (hereinafter also referred to as fluoropolymer (2)) and an alkali metal salt, and the fluoropolymer (2) contains

[0119] Formula:

[0120] -[CR 1 R 2 -CR 3 R 4 -

[0121] (In the formula, R 1 ~R 4Each independently is H, F, Cl, CF 3 , OR 11 (R 11 is an organic group having 1 to 8 carbon atoms). Among them, R 1 ~R 4 at least one of which is F) the structural unit (1) represented by, and

[0122] Formula:

[0123] -[CR 5 R 6 -CR 7 R 8 -

[0124] (In the formula, R 5 ~R 8 Each independently is H, an alkyl group having 1 to 3 carbon atoms, a functional group containing a heteroatom other than a fluorine atom, or a group containing the above functional group. Among them, R 5 ~R 8 at least one of which is a functional group containing a heteroatom other than a fluorine atom or a group containing the above functional group) the structural unit (2) represented by, and does not contain the formula: -(R a O) m -(R a is a perfluoroalkylene group, m is an integer of 2 or more) the structure represented by.

[0125] The composite (2) of the present invention can exhibit excellent ion conductivity and withstand voltage.

[0126] The above-mentioned fluoropolymer (2) has excellent solubility in the above-mentioned alkali metal salt, so the composite (2) can exhibit excellent ion conductivity, for example, excellent alkali metal ion conductivity. In addition, since it contains the above-mentioned fluoropolymer (2), excellent withstand voltage can be exhibited.

[0127] As described below, the composite (2) of the present invention can be suitably used as a constituent material of a battery.

[0128] The above-mentioned fluoropolymer (2) does not contain the formula: -(R a O) m -(R a is a perfluoroalkylene group, m is an integer of 2 or more) the structure represented by. Although the above-mentioned fluoropolymer (2) does not contain the above structure, the composite (2) can still exhibit excellent ion conductivity and withstand voltage.

[0129] The above-mentioned fluoropolymer (2) preferably does not contain the formula: -(R b O) n -(R ba structure represented by a non-fluorinated alkylene group, where n is an integer of 1 or more).

[0130] In the above structural unit (1), R 1 ~R 4 are independently H, F, Cl, CF 3 , OR 11 (R 11 is an organic group having 1 to 8 carbon atoms). Among them, at least one of R 1 ~R 4 is F.

[0131] As the above organic group of R 11 , the number of carbon atoms is preferably 1 to 5, more preferably 1 to 3.

[0132] As the above organic group, an alkyl group that can be fluorinated is preferred, a fluoroalkyl group is more preferred, and a perfluoroalkyl group is further preferred.

[0133] As the above perfluoroalkyl group, perfluoromethyl, perfluoroethyl, perfluoropropyl, perfluorobutyl, perfluoropentyl, perfluorohexyl, etc. can be mentioned, and perfluoromethyl and perfluoropropyl are particularly preferred.

[0134] The above structural unit (1) is preferably based on the formula:

[0135] CR 1 R 2 =CR 3 R 4

[0136] (In the formula, R 1 ~R 4 are the same as above) represents a structural unit of the fluoromonomer (a).

[0137] As the above fluoromonomer (a), monofluoroethylene, trifluoroethylene, vinylidene fluoride (VdF), tetrafluoroethylene (TFE), chlorotrifluoroethylene (CTFE), hexafluoropropylene (HFP), perfluoro(alkyl vinyl ether) (PAVE) with an alkyl group having 1 to 8 carbon atoms, etc. can be mentioned, and one or more than two kinds can be used.

[0138] As PAVE, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), perfluoro(butyl vinyl ether), perfluoro(pentyl vinyl ether), perfluoro(hexyl vinyl ether), etc. can be mentioned, and perfluoro(methyl vinyl ether) (PMVE) and perfluoro(propyl vinyl ether) (PPVE) are particularly preferred.

[0139] As the above-mentioned fluorine monomer (a), it is preferably at least one selected from the group consisting of TFE, HFP, CTFE, VdF, PMVE, and PPVE, more preferably at least one selected from the group consisting of TFE and HFP, and further preferably TFE.

[0140] As the above-mentioned structural unit (1), examples include -[CH 2 -CHF]-, -[CH 2 -CF 2 -, -[CF 2 -CHF]-, -[CF 2 -CF 2 -, -[CF 2 -CFCl]-, -[CF 2 -CFCF 3 -, -[CF 2 -CFORf 11 -(where Rf 11 is a perfluoroalkyl group having 1 to 8 carbon atoms), etc., and one or more of them can be used.

[0141] Among them, it is preferably at least one selected from the group consisting of -[CF 2 -CF 2 -, -[CF 2 -CFCF 3 -, -[CF 2 -CFCl]-, -[CH 2 -CF 2 -, -[CF 2 -CFOCF 3 -, and -[CF 2 -CFOC 3 F 7 -, more preferably at least one selected from the group consisting of -[CF 2 -CF 2 -, and -[CF 2 -CFCF 3 -, and further preferably -[CF 2 -CF 2 -.

[0142] The repeating number of the above-mentioned structural unit (1) is preferably 10 to 1000, more preferably 100 to 500.

[0143] In the above-mentioned structural unit (2), R 5 to R 8 are each independently H, an alkyl group having 1 to 3 carbon atoms, a functional group containing a heteroatom other than a fluorine atom, or a group containing the above-mentioned functional group. Among them, R 5 to R8 At least one of them is a functional group containing a heteroatom other than a fluorine atom or a group containing the above functional group.

[0144] R 5 ~R 8 When two or more of them are the above functional group or a group containing the above functional group, they may be bonded to each other.

[0145] As R 5 ~R 8 The number of carbon atoms of the above alkyl group as R

[0146] ~R 5 ~R 8 is 1 to 3, preferably 1 or 2, more preferably 1.

[0147] As the above functional group, hydroxyl group (excluding the hydroxyl group in carboxyl group. The same applies hereinafter), carboxyl group, carbamate group, amide group, carbonyl group, carbonate group, ester group, ether group, amino group, isocyanate group, group represented by -COOCO-, mercapto group, silyl group, silicate group, epoxy group, cyano group, etc. can be mentioned. Among them, at least one selected from the group consisting of hydroxyl group, amide group, carbonate group, ether group and ester group is preferred, at least one selected from the group consisting of hydroxyl group, amide group, carbonate group and ester group is more preferred, and at least one selected from the group consisting of hydroxyl group, amide group and ester group is further preferred.

[0148] The number of carbon atoms of the above functional group or a group containing the above functional group is preferably 0 to 20, more preferably 0 to 10.

[0149] The above functional group or a group containing the above functional group is preferably hydroxyl group, a group having a lactam structure, ether group, acyloxy group, or a group containing at least one of them, more preferably hydroxyl group, a group having a 5- to 6-membered lactam structure, ether group, acyloxy group, or a group containing at least one of them, further preferably hydroxyl group, pyrrolidone group, ether group, acetoxy group, or a group containing at least one of them, still further preferably hydroxyl group, pyrrolidone group, ether group or acetoxy group, even further preferably hydroxyl group, pyrrolidone group or acetoxy group, particularly preferably hydroxyl group or pyrrolidone group, and most preferably pyrrolidone group.

[0150] In the above structural unit (2), preferably R 5~R 8 One or both of them are a functional group containing a heteroatom other than a fluorine atom or a group containing the above functional group.

[0151] In addition, in the above structural unit (2), R 5 and R 6 being H, R 7 being H or an alkyl group having 1 to 3 carbon atoms, and R 8 being a functional group containing a heteroatom other than a fluorine atom or a group containing the above functional group is one of the preferred modes.

[0152] One or more than two kinds of the above structural unit (2) can be used.

[0153] The above structural unit (2) is preferably based on the formula:

[0154] CR 5 R 6 =CR 7 R 8

[0155] (In the formula, R 5 ~R 8 are the same as above) represents a structural unit of a monomer (hereinafter also referred to as a heteroatom-containing monomer).

[0156] As the above heteroatom-containing monomer, a hydroxy group-containing monomer, an amide group-containing monomer, an ester group-containing monomer, a carboxyl group-containing monomer, an amino group-containing monomer, a hydrolyzable silyl group-containing monomer, an ether group-containing monomer, etc. can be cited, and one or more than two kinds can be used.

[0157] As the above hydroxy group-containing monomer, at least one selected from the group consisting of vinyl alcohol, hydroxyalkyl vinyl ether, hydroxyalkyl allyl ether, vinyl hydroxycarboxylate, allyl hydroxycarboxylate, and hydroxyalkyl (meth)acrylate is preferred, more preferably at least one selected from the group consisting of vinyl alcohol, hydroxyalkyl vinyl ether, and hydroxyalkyl allyl ether, further preferably at least one selected from the group consisting of vinyl alcohol and hydroxyalkyl vinyl ether, and particularly preferably vinyl alcohol.

[0158] As the above hydroxyalkyl vinyl ether, 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 2-hydroxy-2-methylpropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxy-2-methylbutyl vinyl ether, 5-hydroxypentyl vinyl ether, 6-hydroxyhexyl vinyl ether, 4-(hydroxymethyl)cyclohexylmethyl vinyl ether, etc. can be cited.

[0159] As the above hydroxyalkyl allyl ether, 2-hydroxyethyl allyl ether, 4-hydroxybutyl allyl ether, glycerol monoallyl ether, etc. can be cited.

[0160] Examples of the above vinyl hydroxycarboxylates include vinyl glycolate, vinyl lactate, vinyl 3-hydroxybutyrate, vinyl 6-hydroxyhexanoate, vinyl 4-hydroxycyclohexylacetate, and the like.

[0161] Examples of the above allyl hydroxycarboxylates include allyl glycolate, allyl lactate, allyl 3-hydroxybutyrate, allyl 6-hydroxyhexanoate, allyl 4-hydroxycyclohexylacetate, and the like.

[0162] Examples of the above hydroxyalkyl (meth)acrylates include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and the like.

[0163] Among the above hydroxy group-containing monomers, those preferably selected are at least one monomer selected from the group consisting of vinyl alcohol and

[0164] Formula (A): CH 2 =CH-(CH 2 ) l -O-(CH 2 ) m -OH

[0165] (In the formula, l is 0 or 1, and m is an integer of 2 to 20), and more preferably at least one monomer selected from the group consisting of vinyl alcohol, 4-hydroxybutyl vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxyethyl allyl ether, and 4-hydroxybutyl allyl ether, and particularly preferably vinyl alcohol.

[0166] Examples of the above amide group-containing monomers include N-vinyl-β-propiolactam, N-vinyl-2-pyrrolidone, N-vinyl-γ-valerolactam, N-vinyl-2-piperidone, N-vinyl-heptolactam and other N-vinyl lactam compounds, non-cyclic N-vinyl amide compounds such as N-vinylformamide, N-methyl-N-vinylacetamide, non-cyclic N-allyl amide compounds such as N-allyl-N-methylformamide, allylurea, N-allyl lactam compounds such as 1-(2-propenyl)-2-pyrrolidone, (meth)acrylamide, N,N-dimethylacrylamide, N-isopropylacrylamide and other acrylamide compounds.

[0167] Examples of the above amide group-containing monomers also include formula (i):

[0168] [Chemical formula 2]

[0169]

[0170] (In the formula, R 1 and R 2 are independently H or an alkyl group having 1 to 10 carbon atoms), and formula (ii):

[0171] [Chemical Formula 3]

[0172]

[0173] (wherein, R 1 and R 2 are independently H or an alkyl group having 1 to 10 carbon atoms), and compounds represented thereby, etc.

[0174] In the above formulas, R 1 and R 2 may bond to each other to form a ring.

[0175] As the above amide group-containing monomer, an N-vinyl lactam compound or an acyclic N-vinyl amide compound is preferably used, and more preferably at least one selected from the group consisting of N-vinyl-β-propiolactam, N-vinyl-2-pyrrolidone, N-vinyl-γ-valerolactam, N-vinyl-2-piperidone, and N-vinyl-heptalactam. Particularly preferably, at least one selected from the group consisting of N-vinyl-2-pyrrolidone and N-vinyl-2-piperidone, and particularly preferably N-vinyl-2-pyrrolidone.

[0176] As the above amide group-containing monomer, the compound represented by the above formula (i) is also preferably used.

[0177] As the above ester group-containing monomer, isopropenyl acetate, a vinyl ester that contains neither a hydroxyl group nor an aromatic ring, a vinyl carboxylate that contains an aromatic ring but does not contain a hydroxyl group, etc. can be cited.

[0178] As the above vinyl ester that contains neither a hydroxyl group nor an aromatic ring, a vinyl carboxylate is preferably used, and more preferably at least one selected from the group consisting of vinyl acetate, vinyl propionate, vinyl butyrate, isobutyrate vinyl, vinyl pivalate, vinyl hexanoate, vinyl versatate, vinyl laurate, vinyl stearate, and vinyl cyclohexanecarboxylate. Further preferably, at least one selected from the group consisting of vinyl acetate, vinyl versatate, vinyl laurate, vinyl stearate, and vinyl cyclohexanecarboxylate. Particularly preferably, at least one selected from the group consisting of vinyl acetate and vinyl versatate, and most preferably vinyl acetate.

[0179] As the above vinyl carboxylate that contains an aromatic ring but does not contain a hydroxyl group, vinyl benzoate, vinyl p-tert-butylbenzoate, etc. can be cited.

[0180] As the above ester group-containing monomer, a vinyl ester that contains neither a hydroxyl group nor an aromatic ring, isopropenyl acetate is preferably used, and more preferably vinyl acetate and isopropenyl acetate.

[0181] As the above carboxyl group-containing monomer, preferably

[0182] Formula (B): CH 2 =CR 1a -(CH 2 ) n -COOH

[0183] (In the formula, R 1a is a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms; n is an integer of 0 or more), monomers represented by, for example, acrylic acid, methacrylic acid, vinyl acetic acid, pentenoic acid, hexenoic acid, heptenoic acid, octenoic acid, nonenoic acid, decenoic acid, undecenoic acid, dodecenoic acid, tridecenoic acid, tetradecenoic acid, pentadecenoic acid, hexadecenoic acid, heptadecenoic acid, octadecenoic acid, nonadecenoic acid, eicosenoic acid, 22-docosenoic acid, etc. Among them, at least one selected from the group consisting of acrylic acid and undecenoic acid is preferred, and acrylic acid is more preferred.

[0184] In addition, as the above carboxyl group-containing monomer, 3-allyloxypropionic acid, vinyl phthalate, vinyl pyromellitate, crotonic acid, itaconic acid, itaconic acid monoester, maleic acid, maleic acid monoester, maleic anhydride, fumaric acid, fumaric acid monoester, citraconic acid, mesaconic acid, aconitic acid, etc. can also be cited.

[0185] As the above amino group-containing monomer, for example, amino vinyl ethers represented by CH 2 =CH-O-(CH 2 ) x -NH 2 (x = 0 to 10); amines represented by CH 2 =CH-O-CO(CH 2 ) x -NH 2 (x = 1 to 10); and aminomethylstyrene, vinylamine, etc.

[0186] As the above hydrolyzable silyl group-containing monomer, for example, CH 2 =CHCO 2 (CH 2 ) 3 Si(OCH 3 ) 3 , CH 2 =CHCO 2 (CH 2 ) 3 Si(OC 2 H 5 ) 3 , CH 2 =C(CH 3 )CO 2 (CH 2) 3 Si(OCH 3 ) 3 、CH 2 =C(CH 3 )CO 2 (CH 2 ) 3 Si(OC 2 H 5 ) 3 、CH 2 =CHCO 2 (CH 2 ) 3 SiCH 3 (OC 2 H 5 ) 2 、CH 2 =C(CH 3 )CO 2 (CH 2 ) 3 SiC 2 H 5 (OCH 3 ) 2 、CH 2 =C(CH 3 )CO 2 (CH 2 ) 3 Si(CH 3 ) 2 (OC 2 H 5 )、CH 2 =C(CH 3 )CO 2 (CH 2 ) 3 Si(CH 3 ) 2 OH、CH 2 =CH(CH 2 ) 3 Si(OCOCH 3 ) 3 、CH 2 =C(CH 3 )CO 2 (CH 2 ) 3 SiC 2 H 5 (OCOCH 3 ) 2 、CH 2 =C(CH 3 )CO 2 (CH 2 ) 3SiCH 3 (N(CH 3 )COCH 3 ) 2 、CH 2 =CHCO 2 (CH 2 ) 3 SiCH 3 [ON(CH 3 )C 2 H 5 2 、CH 2 =C(CH 3 )CO 2 (CH 2 ) 3 SiC 6 H 5 [ON(CH 3 )C 2 H 5 2 etc. (meth)acrylates; CH 2 =CHSi[ON=C(CH 3 )(C 2 H 5 )] 3 、CH 2 =CHSi(OCH 3 ) 3 、CH 2 =CHSi(OC 2 H 5 ) 3 、CH 2 =CHSiCH 3 (OCH 3 ) 2 、CH 2 =CHSi(OCOCH 3 ) 3 、CH 2 =CHSi(CH 3 ) 2 (OC 2 H 5 )、CH 2 =CHSi(CH 3 ) 2 SiCH 3 (OCH 3 ) 2 、CH 2 =CHSiC 2 H 5 (OCOCH 3 ) 2 、CH 2 ​​=CHSiCH 3 [ON(CH 3 )C 2 H 5 2 Vinyl silanes such as vinyltrichlorosilane or their partial hydrolyzates; vinyl ethers such as trimethoxysilylethyl vinyl ether, triethoxysilylethyl vinyl ether, trimethoxysilylbutyl vinyl ether, methyldimethoxysilylethyl vinyl ether, trimethoxysilylpropyl vinyl ether, triethoxysilylpropyl vinyl ether; and so on.

[0187] As the above-mentioned ether group-containing monomer, alkyl vinyl ethers not containing a hydroxyl group can be cited. As the above-mentioned alkyl vinyl ethers not containing a hydroxyl group, methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexyl vinyl ether, dodecyl vinyl ether, octadecyl vinyl ether, etc. can be cited, and at least one selected from the group consisting of ethyl vinyl ether and cyclohexyl vinyl ether is preferred.

[0188] As the above-mentioned hetero group-containing monomer, at least one selected from the group consisting of the above-mentioned hydroxyl group-containing monomer, the above-mentioned amide group-containing monomer, and the above-mentioned ester group-containing monomer is preferred.

[0189] More preferably, at least one selected from the group consisting of the above-mentioned hydroxyl group-containing monomer and the above-mentioned amide group-containing monomer.

[0190] Even more preferably, the above-mentioned amide group-containing monomer.

[0191] Particularly preferably, the compound represented by formula (i).

[0192] Most preferably, N-vinyl-2-pyrrolidone.

[0193] As the above-mentioned hetero group-containing monomer, at least one selected from the group consisting of vinyl alcohol, N-vinyl-2-pyrrolidone, vinyl acetate, and isopropenyl acetate is also preferred.

[0194] More preferably, at least one selected from the group consisting of vinyl alcohol and N-vinyl-2-pyrrolidone.

[0195] Even more preferably, N-vinyl-2-pyrrolidone.

[0196] The repeating number of the above structural unit (2) is preferably 10 to 1000, more preferably 100 to 500.

[0197] ​As the fluoropolymer (2) described above, it is preferred that the structural unit (1) is a structural unit based on at least one selected from the group consisting of TFE and HFP, and the structural unit (2) is a structural unit based on at least one selected from the group consisting of the above-mentioned hydroxyl group-containing monomer, the above-mentioned amide group-containing monomer, and the above-mentioned ester group-containing monomer.

[0198] More preferably, the structural unit (1) is a structural unit based on at least one selected from the group consisting of TFE and HFP, and the structural unit (2) is a structural unit based on at least one selected from the group consisting of the above-mentioned hydroxyl group-containing monomer and the above-mentioned amide group-containing monomer.

[0199] Further preferably, the structural unit (1) is a structural unit based on at least one selected from the group consisting of TFE and HFP, and the structural unit (2) is a structural unit based on the above-mentioned amide group-containing monomer.

[0200] Particularly preferably, the structural unit (1) is a structural unit based on at least one selected from the group consisting of TFE and HFP, and the structural unit (2) is a structural unit based on the compound represented by formula (i).

[0201] Most preferably, the structural unit (1) is a structural unit based on at least one selected from the group consisting of TFE and HFP, and the structural unit (2) is a structural unit based on N-vinyl-2-pyrrolidone.

[0202] As the fluoropolymer (2) described above, it is also preferred that the structural unit (1) is a structural unit based on at least one selected from the group consisting of TFE and HFP, and the structural unit (2) is a structural unit based on at least one selected from the group consisting of vinyl alcohol, N-vinyl-2-pyrrolidone, vinyl acetate, and isopropenyl acetate.

[0203] More preferably, the structural unit (1) is a structural unit based on at least one selected from the group consisting of TFE and HFP, and the structural unit (2) is a structural unit based on at least one selected from the group consisting of vinyl alcohol and N-vinyl-2-pyrrolidone.

[0204] Further preferably, the structural unit (1) is a structural unit based on at least one selected from the group consisting of TFE and HFP, and the structural unit (2) is a structural unit based on N-vinyl-2-pyrrolidone.

[0205] As the fluoropolymer (2) described above, for the reason of further improving the ionic conductivity and the withstand voltage, relative to all the structural units, it is preferable that the structural unit (1) is 99.9 to 0.1 mol%, and the structural unit (2) is 0.1 to 99.9 mol%. Further preferably, the structural unit (1) is 65 to 7 mol%, and the structural unit (2) is 35 to 93 mol%. Further preferably, the structural unit (1) is 55 to 15 mol%, and the structural unit (2) is 45 to 85 mol%. Further preferably, the structural unit (1) is 45 to 20 mol%, and the structural unit (2) is 55 to 80 mol%.

[0206] In addition, particularly, the molar ratio ((1) / (2)) of the structural unit (1) to the structural unit (2) is preferably in the range of 0.07 to 1.50, more preferably in the range of 0.25 to 1.25. Further preferably, it is in the range of 0.25 to 0.82.

[0207] The fluoropolymer (2) described above may be substantially composed only of the structural units (1) and (2).

[0208] The fluoropolymer (2) described above may have other structural units other than the structural units (1) and (2) within the range that does not impair the effect of the composite of the present invention. As the other structural units, structural units based on other fluorine monomers other than the fluorine monomer (a) described above, functional group-containing monomers other than the heteroatom-containing monomer described above, olefins that do not contain a halogen atom and a hydroxyl group, (meth)acrylic monomers having a long-chain hydrocarbon group, vinyl monomers having a long-chain hydrocarbon group, etc. may be mentioned. The total of the other structural units may be 0 to 50 mol%, may be 0 to 40 mol%, may be 0 to 30 mol%, may be 0 to 15 mol%, may be 0 to 5 mol%.

[0209] As other fluorine monomers other than the fluorine monomer (a) described above, examples include: (1) olefins having 3 or more carbon atoms having a fluorine atom bonded to a sp 2 hybridized carbon atom (excluding the fluorine monomer (a)); (2) monomers represented by the general formula: CH 2 =CX-COORf (wherein X is Cl, H or an alkyl group, and Rf is a fluoroalkyl group); (3) monomers represented by the general formula: CH 2 =CH-Rf (wherein Rf is a fluoroalkyl group); (4) monomers represented by the general formula: CH 2 =CH-ORf (wherein Rf is a fluoroalkyl group); and so on.

[0210] As the alkyl group, an alkyl group having 1 to 3 carbon atoms may be mentioned, and a methyl group is preferable.

[0211] As the above-mentioned fluoroalkyl group, a linear or branched fluoroalkyl group having 1 to 12 carbon atoms is preferred.

[0212] As the above-mentioned other fluorine monomers, trifluorostyrene, general formula: CH 2 =CFRf 1 (wherein, Rf 1 is a linear or branched fluoroalkyl group having 1 to 12 carbon atoms) represented fluorine monomers, fluoroalkyl vinyl ethers, fluoroalkyl ethylenes, trifluoropropene, pentafluoropropene, trifluorobutene, tetrafluoroisobutene, hexafluoroisobutene, trifluorostyrene, etc.

[0213] As the functional group-containing monomers other than the above-mentioned heteroatom-containing monomers, cinnamic acid etc. can be cited.

[0214] As the olefins not containing a halogen atom and a hydroxyl group as mentioned above, non-fluorine-based olefins such as ethylene, propylene, n-butene, isobutene etc. can be cited.

[0215] The weight average molecular weight of the above-mentioned fluorine-containing polymer (2) is preferably 10,000 or more, more preferably 15,000 or more, further preferably 20,000 or more, and particularly preferably 30,000 or more. More preferably 15,000 to 500,000, further preferably 20,000 to 300,000, and particularly preferably 30,000 to 300,000. The above-mentioned weight average molecular weight can be determined by gel permeation chromatography (GPC).

[0216] The above-mentioned fluorine-containing polymer (2) can be produced, for example, by polymerizing the monomers corresponding to each structural unit using a known polymerization method.

[0217] When the above-mentioned fluorine-containing polymer (2) has a structural unit based on vinyl alcohol (-[CH 2 -CH(OH)]-), it can be produced by the following methods: a method of polymerizing a fluorine monomer and a vinyl ester monomer and then hydroxylating the ester moiety by saponification etc.; a method of polymerizing a fluorine monomer and a vinyl ether monomer and then converting the alkoxy group to a hydroxyl group by deprotection; etc.

[0218] As the above-mentioned alkali metal salt in the above-mentioned composite (2), the same substances as those usable for the above-mentioned composite (1) can be cited.

[0219] The above-mentioned alkali metal salt is preferably dissolved in the above-mentioned fluorine-containing polymer (2). Thereby, the ionic conductivity is further improved.

[0220] The content of the above-mentioned alkali metal salt is preferably 0.1 to 500 parts by mass, more preferably 1 to 100 parts by mass, and further preferably 10 to 50 parts by mass with respect to 100 parts by mass of the above-mentioned fluorine-containing polymer (2).

[0221] The above complex (2) preferably further contains an organic heterogeneous system crystal. Thereby, the ionic conductivity is further improved.

[0222] The above organic heterogeneous system crystal is preferably a flexible viscous crystal (organic ionic plastic crystal (OIPC)) or a molecular crystal containing a heteroatom and a carbon atom. The above organic heterogeneous system crystal preferably further contains a hydrogen atom.

[0223] Examples of the heteroatom included in the above organic heterogeneous system crystal include a boron atom, an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a silicon atom, a halogen atom, etc.

[0224] Examples of the above organic ionic plastic crystal include a compound composed of a cation containing at least one selected from the group consisting of a nitrogen atom and a phosphorus atom and an anion containing at least one selected from the group consisting of a boron atom, an oxygen atom, a nitrogen atom, a sulfur atom, and a fluorine atom.

[0225] Examples of the above cation include an ammonium-based cation, a phosphonium-based cation, etc. Among them, an alkylammonium cation and an alkylphosphonium cation are preferred.

[0226] Examples of the above anion include: a borate-based anion that may have a fluorine atom, a sulfonimide-based anion that may have a fluorine atom, a phosphate-based anion that may have a fluorine atom, H 2 F 3 - etc. Among them, a borate-based anion having a fluorine atom, a sulfonimide-based anion having a fluorine atom, and a phosphate-based anion having a fluorine atom are preferred.

[0227] As the above organic ionic plastic crystal, a known compound such as succinonitrile can be used.

[0228] Examples of the above molecular crystal include a compound containing at least one selected from the group consisting of a boron atom, an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, and a fluorine atom.

[0229] The above molecular crystal preferably has an aromatic ring. Examples of the above aromatic ring include a benzene ring, a thiophene ring, etc.

[0230] As the above molecular crystal, a known compound can be used.

[0231] The content of the above organic heterogeneous system crystal is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 50 parts by mass, relative to 100 parts by mass of the above fluorine-containing polymer (2).

[0232] The above complex (2) may further contain other components other than the above fluorine-containing polymer (2), the above alkali metal salt, and the above organic heterogeneous system crystal as needed.

[0233] In the above complex (2), relative to the above complex (2), the volatile component content is preferably 1% by mass or less, more preferably 0.1% by mass or less, still more preferably 0.01% by mass or less, and particularly preferably 0.001% by mass or less. The lower limit of the volatile component content is not particularly limited and may be 0% by mass or may be 0.0001% by mass.

[0234] The volatile component content is a value obtained by measuring the amount of gas obtained by heating a sample at 60 °C for 60 minutes.

[0235] The transference number of alkali metal ions in the above complex (2) is preferably 0.3 or more, more preferably 0.5 or more, and still more preferably 0.8 or more. The upper limit of the transference number of alkali metal ions is not particularly limited.

[0236] The transference number of alkali metal ions may be the transference number of lithium ions, sodium ions or potassium ions, and is preferably the transference number of lithium ions.

[0237] The transference number of alkali metal ions is a value obtained by the following method.

[0238] Perform complex AC impedance measurement to estimate the resistance value (R0). Thereafter, perform DC polarization measurement to confirm the case where the current value reaches a constant value (assuming the initial current value is I0 and the current value at the time of reaching a constant is Is). Thereafter, perform complex AC impedance measurement again to estimate the resistance value (Rs).

[0239] The transference number of alkali metal ions (t+) is obtained by the Evans formula (Evans formula) represented by the following formula.

[0240] t+ = Is(ΔV - I0·R0) / I0(ΔV - Is·Rs)

[0241] ΔV: Applied voltage

[0242] R0, Rs, I0, Is: As described above

[0243] The above complex (2) can be used in fields requiring ion conductivity and voltage resistance, and can be suitably used as a constituent material of a battery, particularly a secondary battery, for example.

[0244] The above complex (2) is preferably used in an electrolyte. The electrolyte may be a solid electrolyte or a gel electrolyte. The above complex (2) can be used as the above electrolyte or as a constituent material of the above electrolyte.

[0245] Since the above complex (2) can also be impregnated into the voids between the solid particles, it is also preferable that the above complex (2) is present between the solid particles constituting the battery, particularly between the inorganic solid particles (preferably in the voids between these particles). In this mode, it is also preferable that the above complex (2) functions as an electrolyte.

[0246] The above complex (2) can be suitably used as a constituent material of an all-solid-state battery, particularly an all-solid-state secondary battery. Among them, it can be particularly suitably used as a constituent material of an all-solid-state battery including an inorganic solid electrolyte.

[0247] The present invention also relates to a method for manufacturing a complex, which is characterized in that it includes step (1) and step (2),

[0248] Step (1) is a step of obtaining a mixture by mixing a fluorine-containing polymer, an alkali metal salt, and a solvent. The fluorine-containing polymer includes the formula:

[0249] -[CR 1 R 2 -CR 3 R 4 -

[0250] (In the formula, R 1 ~R 4 are independently H, F, Cl, CF 3 , OR 11 (R 11 is an organic group having 1 to 8 carbon atoms). Among them, at least one of R 1 ~R 4 is F) represents a structural unit (1), and

[0251] Formula:

[0252] -[CR 5 R 6 -CR 7 R 8 -

[0253] (In the formula, R 5 ~R 8 are independently H, an alkyl group having 1 to 3 carbon atoms, a functional group containing a heteroatom other than a fluorine atom, or a group containing the above functional group. Among them, at least one of R 5 ~R 8 is a functional group containing a heteroatom other than a fluorine atom or a group containing the above functional group) represents a structural unit (2), and does not include the formula: -(R a O) m -(R a is a perfluoroalkylene group, and m is an integer of 2 or more) represents a structure;

[0254] Step (2) is a step of obtaining a complex containing the above fluoropolymer and the above alkali metal salt by removing the above solvent from the above mixture.

[0255] The above complex (2) can be appropriately produced by the production method of the present invention.

[0256] Examples of the above fluoropolymer and the above alkali metal salt in the production method of the present invention include the same substances as the fluoropolymer (fluoropolymer (2)) and the alkali metal salt in the above complex (2).

[0257] The above solvent in step (1) is not limited as long as it can dissolve the above fluoropolymer and the above alkali metal salt, and may be water or an organic solvent, preferably an organic solvent.

[0258] The above solvent is further preferably capable of dissolving the above organic heterogeneous crystal.

[0259] Examples of the above organic solvent include: nitrogen-containing organic solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and dimethylformamide; ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; ether solvents such as tetrahydrofuran, dioxane, ethyl cellosolve, methyl cellosolve, diethylene glycol dimethyl ether, and triethylene glycol dimethyl ether; aromatic hydrocarbon solvents such as xylene, toluene, and solvent naphtha; aliphatic hydrocarbon solvents such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-undecane, n-dodecane, and mineral spirits; mixed solvents thereof; and the like.

[0260] Among them, nitrogen-containing organic solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and dimethylformamide; and ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, and methyl isobutyl ketone are preferred.

[0261] In step (1), the mixing order of the respective components is not particularly limited. For example, the above fluoropolymer and the above alkali metal salt can be simultaneously mixed and dissolved in the above solvent, or the above fluoropolymer can be mixed and dissolved in the above solvent, and then the above alkali metal salt can be mixed and dissolved, or the above alkali metal salt can be mixed and dissolved in the above solvent, and then the above fluoropolymer can be mixed and dissolved.

[0262] In step (1), the above-mentioned organic heterogeneous crystals can be further mixed. The mixing order in this case is not particularly limited. The above-mentioned organic heterogeneous crystals can be mixed and dissolved in the above-mentioned solvent simultaneously with the above-mentioned fluoropolymer and the above-mentioned alkali metal salt, can be mixed and dissolved in the above-mentioned solvent before the above-mentioned fluoropolymer and the above-mentioned alkali metal salt, can be mixed and dissolved in the above-mentioned solvent after the above-mentioned fluoropolymer and the above-mentioned alkali metal salt, or can be mixed and dissolved in the above-mentioned solvent between the above-mentioned fluoropolymer and the above-mentioned alkali metal salt.

[0263] The removal of the above-mentioned solvent in step (2) can be carried out by drying, for example. Heating can be performed as needed.

[0264] The conditions for drying and heating can be appropriately determined according to the type of the above-mentioned solvent and the like.

[0265] The manufacturing method of the present invention can further include step (3) of coating the above-mentioned mixture obtained in step (1) onto an object.

[0266] Step (3) is preferably carried out after the implementation of step (1) and before the implementation of step (2).

[0267] The coating in step (3) can be carried out by methods such as brushing, spraying, dip coating, casting coating, dispensing coating, screen coating, etc.

[0268] The above-mentioned object in step (3) is not particularly limited and can be selected according to the use. When the above-mentioned composite is used in a battery (preferably a all-solid-state battery), for example, it can be an electrolyte layer (preferably an inorganic solid electrolyte layer) or an electrode layer.

[0269] The present invention also relates to a battery including the above-mentioned structure or the above-mentioned composite (composite (2)) of the present invention.

[0270] The battery of the present invention is preferably a secondary battery.

[0271] The battery of the present invention is preferably an alkali metal ion battery such as a lithium ion battery, a sodium ion battery, a potassium ion battery, etc., and more preferably a lithium ion battery.

[0272] The battery of the present invention can be a solid electrolyte battery, a gel electrolyte battery, etc. The above-mentioned solid electrolyte battery can be an organic solid electrolyte battery or an inorganic solid electrolyte battery. The above-mentioned solid electrolyte battery can be an all-solid-state battery.

[0273] The above-mentioned organic solid electrolyte battery can include the above-mentioned composite (2). For example, the above-mentioned composite (2) can be used as an organic solid electrolyte (solid polymer electrolyte).

[0274] The above-mentioned organic solid electrolyte battery can be a all-solid-state battery.

[0275] The above-mentioned inorganic solid electrolyte battery can have the structure or composite (2) of the present invention. For example, the structure of the present invention can be used in the basic composition of the above-mentioned inorganic solid electrolyte battery. Additionally, for example, the above-mentioned composite (2) can be present between inorganic solid particles (such as inorganic solid particles constituting an electrode or an electrolyte) (preferably in the voids between these particles). In this manner, the above-mentioned composite (2) can also function as an electrolyte.

[0276] The above-mentioned inorganic solid electrolyte battery can be a all-solid-state battery.

[0277] The above-mentioned gel electrolyte battery can have the above-mentioned composite (2). For example, the above-mentioned composite (2) can be used as a polymer material for holding a solvent or an electrolytic solution in the gel electrolyte.

[0278] The mode in which the battery of the present invention is a all-solid-state battery is one of the preferred modes. The above-mentioned all-solid-state battery is preferably a all-solid-state secondary battery. Additionally, the above-mentioned all-solid-state battery preferably contains an inorganic solid electrolyte.

[0279] The above-mentioned all-solid-state battery is preferably a all-solid-state alkali metal ion battery such as a all-solid-state lithium ion battery, a all-solid-state sodium ion battery, a all-solid-state potassium ion battery, etc., and more preferably a all-solid-state lithium ion battery.

[0280] The above-mentioned all-solid-state battery preferably has:

[0281] a positive electrode layer,

[0282] a negative electrode layer,

[0283] an inorganic solid electrolyte layer formed between the above-mentioned positive electrode layer and the above-mentioned negative electrode layer,

[0284] and a fluorine-containing polymer layer provided between the above-mentioned positive electrode layer and the above-mentioned inorganic solid electrolyte layer and / or between the above-mentioned negative electrode layer and the above-mentioned inorganic solid electrolyte layer.

[0285] At least one of the above-mentioned positive electrode layer and the above-mentioned negative electrode layer is preferably an electrode layer in the structure of the present invention. The electrode active material and other constituent materials constituting the above-mentioned positive electrode layer and the above-mentioned negative electrode layer are as described above.

[0286] The above-mentioned inorganic solid electrolyte layer is preferably an inorganic solid electrolyte layer in the structure of the present invention. The inorganic solid electrolyte and other constituent materials constituting the above-mentioned inorganic solid electrolyte layer are as described above.

[0287] The fluorine-containing polymer layer described above is preferably the fluorine-containing polymer layer in the structure of the present invention described above or a layer composed of the composite of the present invention described above.

[0288] Examples of the shape of the all-solid-state battery described above include button type, laminated type, cylindrical type, square type, etc.

[0289] The all-solid-state battery described above can be manufactured, for example, by the following method: laminating the positive electrode layer, the fluorine-containing polymer layer (if present), the inorganic solid electrolyte layer, the fluorine-containing polymer layer (if present), and the negative electrode layer in this order, and if necessary, pressing to produce a laminate, accommodating the laminate inside a battery case, and if necessary, riveting the battery case.

[0290] Examples

[0291] Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0292] <Manufacture of composite>

[0293] Examples 1 to 4

[0294] As the polymers, Polymer 1 which is a copolymer of tetrafluoroethylene and N-vinyl-2-pyrrolidone (composition ratio (molar ratio) 48:52) and Polymer 2 which is the copolymer (composition ratio (molar ratio) 36:64) were used. The above polymers, the lithium salts shown in Table 1, and additives were added to acetone as a solvent to prepare a solution containing 20% by mass of lithium salt and 10% by mass of additive relative to the polymer.

[0295] The above solution was coated on a film made of PET, a film was formed using a bar coater, and the solvent was slowly distilled off using a high-temperature dryer to obtain Composites 1 to 4 (solid electrolytes). At this time, the film-forming ability was confirmed by whether the film could be peeled off from the film. The case where the film could be peeled off was evaluated as ○ (able to form a film), and the case where it could not be peeled off was evaluated as × (unable to form a film).

[0296] In addition, the transparency of the obtained film was confirmed. When the film was transparent, it was evaluated as ○, and when it was cloudy, it was evaluated as ×. When the film was transparent, it meant that the lithium salt was sufficiently dissolved in the polymer.

[0297] The results are shown in Table 1.

[0298] In addition, the amount of volatile components of the obtained composite was measured by the following method. The results are shown in Table 2.

[0299] <Amount of volatile components>

[0300] The obtained complexes 1 to 4 were heated at 60 °C for 60 minutes, and the amount of gas generated was determined. The mass ratio of the above gas to the complex before heating was taken as the volatile component amount.

[0301] Comparative Examples 1 and 2

[0302] As the polymer, Polymer 3 (polyethylene oxide) was used instead of Polymer 1, and complexes 5 and 6 were prepared in the same manner as in Example 1 except for this point, and the film-forming ability and transparency were evaluated. The results are shown in Table 1.

[0303] [Table 1]

[0304] Solid electrolyte Lithium salt Polymer Additive Film-forming ability Transparency Example 1 Composite 1 LiTFSI Polymer 1 Succinonitrile 〇 〇 Example 2 Composite 2 LiFSI Polymer 1 Succinonitrile 〇 〇 Example 3 Composite 3 LiFSI Polymer 2 Succinonitrile 〇 〇 Example 4 Composite 4 LiTFSI Polymer 1 None 〇 〇 Comparative Example 1 Composite 5 LiTFSI Polymer 3 Succinonitrile × × Comparative Example 2 Composite 6 LiTFSI Polymer 3 None × ×

[0305] [Table 2]

[0306]

[0307] <Electrochemical Stability Measurement>

[0308] Measurements based on the LSV (linear sweep voltammetry) method were carried out to evaluate the oxidation resistance. In the LSV measurement, a solution obtained by using propylene carbonate as a solvent, adding 3% by mass of LiTFSI, and 2% by mass of succinonitrile was used. Two types of samples were prepared: a sample (Example 5) in which 1% by mass of the above Polymer 1 was added to this solution and a sample (Comparative Example 3) in which 1% by mass of the above Polymer 3 was added. Each prepared measurement solution was added to the measurement container, and a platinum electrode was immersed in the working electrode, and a lithium metal was immersed in the counter electrode and the reference electrode as an LSV measurement cell. Potential scanning was performed from OCV (open circuit voltage) at a scanning rate of 5 mV / s on the oxidation side up to 8 V (vs. Li + / Li) for measurement.

[0309] The results are shown in Figure 1 .

[0310] <Ionic Conductivity Measurement>

[0311] As the sample for this measurement, the same complexes as in Example 1 and Comparative Example 2 were used. However, the PET film at the time of film formation was changed to a copper foil, the polymer solution was coated on the copper foil, and after solvent distillation removal, it was not peeled off from the copper foil and was left as it was and hollowed out to the size of a button type (since the film formation of Complex 6 could not be carried out, the process was changed in this way).

[0312] Using stainless steel as the working electrode and the counter electrode, sandwich the above-mentioned copper foil and composite film between these electrodes to fabricate a button-type battery. Connect the fabricated battery to a complex AC impedance measuring device using copper wires and measure its resistance. During the measurement, place the battery in a thermostat set at 60 °C for 3 hours and perform the measurement after the electrolyte and the electrodes are fully integrated. The ionic conductivity σ (S / cm) is defined as follows.

[0313] σ = C / R (C = l / s)

[0314] Here, l represents the thickness of the specimen, s represents its area, and R represents the resistance.

[0315] The results are shown in Table 3.

[0316] [Table 3]

[0317] Solid electrolyte Ionic conductivity (60 °C, S / cm) Example 1 Composite 1 <![CDATA[2.6×10 -5 > Comparative Example 2 Composite 6 <![CDATA[8.0×10 -6 >

Claims

1. A structure, characterized in that, the structure has an electrode layer, an inorganic solid electrolyte layer, and a fluoropolymer layer provided between the electrode layer and the inorganic solid electrolyte layer, the fluoropolymer layer is composed of a complex containing a fluoropolymer and an alkali metal salt, the fluoropolymer contains a heteroatom other than a fluorine atom and a fluorine atom on the main chain, The fluoropolymer contains a structural unit (1) and a structural unit of formula (2), and does not contain a structure represented by -(R a O) m -, where R a is a perfluoroalkylene group and m is an integer of 2 or more. the structural unit (1) is based on at least one selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, perfluoro(methyl vinyl ether), and perfluoro(propyl vinyl ether), The structural unit (2) is represented by the formula -[CR 5 R 6 -CR 7 R 8 -, where, in the formula, R 5 ~R 8 are independently of each other H, an alkyl group having 1 to 3 carbon atoms, a functional group containing a heteroatom other than a fluorine atom, or a group containing the functional group, wherein at least one of R 5 ~R 8 is a functional group containing a heteroatom other than a fluorine atom or a group containing the functional group. in the fluoropolymer, relative to all structural units, the structural unit (1) is 36 mol% to 48 mol%, and the structural unit (2) is 52 mol% to 64 mol%.

2. The structure according to claim 1, wherein, the complex further contains an organic heterogeneous crystal.

3. The structure according to claim 1 or 2, wherein, the fluoropolymer is a copolymer of tetrafluoroethylene and N-vinyl-2-pyrrolidone.

4. The structure according to claim 1 or 2, wherein, the alkali metal salt is at least one selected from the group consisting of lithium bis(trifluoromethanesulfonyl)imide and lithium bis(monofluoromethanesulfonyl)imide.

5. The structure according to claim 2, wherein, the organic heterogeneous crystal is succinonitrile.

6. The structure according to claim 2, wherein, the fluoropolymer is a copolymer of tetrafluoroethylene and N-vinyl-2-pyrrolidone, the alkali metal salt is at least one selected from the group consisting of lithium bis(trifluoromethanesulfonyl)imide and lithium bis(monofluoromethanesulfonyl)imide, the organic heterogeneous crystal is succinonitrile.

7. A complex, characterized in that, It contains a fluoropolymer and an alkali metal salt. The fluoropolymer contains structural unit (1) and structural unit (2), and does not contain the structure represented by the formula -(R a O) m -, where R a is a perfluoroalkylene group and m is an integer of 2 or more. The structural unit (1) is represented by the formula -[CR 1 R 2 -CR 3 R 4 -, wherein R 1 ~R 4 are independently of one another H, F, Cl, CF 3 , OR 11 , R 11 is an organic group having 1 to 8 carbon atoms, and at least one of R 1 ~R 4 is F; The structural unit (2) is represented by the formula -[CR 5 R 6 -CR 7 R 8 -, where R 5 ~R 8 are independently of one another H, an alkyl group having 1 to 3 carbon atoms, a functional group containing a heteroatom other than a fluorine atom, or a group containing the functional group, provided that at least one of R 5 ~R 8 is a functional group containing a heteroatom other than a fluorine atom or a group containing the functional group. the volatile component content is 1% by mass or less, in the fluoropolymer, relative to all structural units, the structural unit (1) is 36 mol% to 48 mol%, and the structural unit (2) is 52 mol% to 64 mol%.

8. The complex according to claim 7, wherein, the functional group containing a heteroatom other than a fluorine atom is at least one selected from the group consisting of a hydroxyl group, an amide group, a carbonate group, and an ester group.

9. The complex according to claim 7 or 8, wherein, the structural unit (1) is a structural unit based on at least one selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, vinylidene fluoride, perfluoro(methyl vinyl ether), and perfluoro(propyl vinyl ether).

10. The complex according to claim 7 or 8, wherein, the structural unit (1) is a structural unit based on at least one selected from the group consisting of tetrafluoroethylene and hexafluoropropylene, the structural unit (2) is a structural unit based on the compound represented by formula (i), formula (i): [Chemical formula 1] In the formula, R 1 and R 2 are independently H or an alkyl group having 1 to 10 carbon atoms.

11. The complex according to claim 7 or 8, which further contains an organic heterogeneous crystal.

12. The complex according to claim 11, wherein, the organic heterogeneous crystal is a soft viscous crystal or a molecular crystal containing a heteroatom and a carbon atom.

13. The complex according to claim 7 or 8, wherein, The structural unit (1) is a structural unit based on tetrafluoroethylene, The structural unit (2) is a structural unit based on N-vinyl-2-pyrrolidone.

14. The composite according to claim 7 or 8, wherein, The alkali metal salt is at least one selected from the group consisting of lithium bis(trifluoromethanesulfonylimide) and lithium bis(monofluoromethanesulfonylimide).

15. The composite according to claim 11, wherein, The organic heterogeneous crystal is succinonitrile.

16. The composite according to claim 11, wherein, The structural unit (1) is a structural unit based on tetrafluoroethylene, The structural unit (2) is a structural unit based on N-vinyl-2-pyrrolidone, The alkali metal salt is at least one selected from the group consisting of lithium bis(trifluoromethanesulfonylimide) and lithium bis(monofluoromethanesulfonylimide), The organic heterogeneous crystal is succinonitrile.

17. Use of the composite according to any one of claims 7 to 16 as an electrolyte.

18. A battery comprising the structure according to any one of claims 1 to 6 or the composite according to any one of claims 7 to 16.

19. The battery according to claim 18, which is an all-solid-state battery.

20. A method for manufacturing a composite, characterized in that, It includes step (1), step (2) and step (3), Step (1) is a step of obtaining a mixture by mixing a fluoropolymer, an alkali metal salt, and a solvent. The fluoropolymer contains structural unit (1) and structural unit (2), and does not contain a structure represented by the formula -(R a O) m -, where R a is a perfluoroalkylene group and m is an integer of 2 or more. The structural unit (1) is represented by the formula -[CR 1 R 2 -CR 3 R 4 -, where R 1 ~R 4 are independently of each other H, F, Cl, CF 3 , OR 11 , R 11 is an organic group having 1 to 8 carbon atoms, and at least one of R 1 ~R 4 is F; The structural unit (2) is represented by the formula -[CR 5 R 6 -CR 7 R 8 -, where R 5 ~R 8 are independently of each other H, an alkyl group having 1 to 3 carbon atoms, a functional group containing a heteroatom other than a fluorine atom, or a group containing the functional group, wherein at least one of R 5 ~R 8 is a functional group containing a heteroatom other than a fluorine atom or a group containing the functional group; The step (2) is a step of obtaining a composite containing the fluoropolymer and the alkali metal salt by removing the solvent from the mixture so that the amount of volatile components is 1% by mass or less; The step (3) is a step of coating the mixture obtained in step (1) onto an object; In the fluoropolymer, relative to all structural units, the structural unit (1) is 36 mol% to 48 mol%, and the structural unit (2) is 52 mol% to 64 mol%.

21. The manufacturing method according to claim 20, wherein, The structural unit (1) is a structural unit based on tetrafluoroethylene, The structural unit (2) is a structural unit based on N-vinyl-2-pyrrolidone.

22. The manufacturing method according to claim 20 or 21, wherein, The alkali metal salt is at least one selected from the group consisting of lithium bis(trifluoromethanesulfonylimide) and lithium bis(monofluoromethanesulfonylimide).

23. The manufacturing method according to claim 20 or 21, wherein, In step (1), an organic heterogeneous crystal is further mixed, The organic heterogeneous crystal is succinonitrile.

24. The manufacturing method according to claim 20 or 21, wherein, The structural unit (1) is a structural unit based on tetrafluoroethylene, The structural unit (2) is a structural unit based on N-vinyl-2-pyrrolidone, The alkali metal salt is at least one selected from the group consisting of lithium bis(trifluoromethanesulfonylimide) and lithium bis(monofluoromethanesulfonylimide), In step (1), an organic heterogeneous crystal is further mixed, The organic heterogeneous crystal is succinonitrile.

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