Electrolyte solution, lithium-ion conductive material, battery, and method for manufacturing lithium-ion conductive material

Abstract

Conventional electrolyte solutions and lithium-ion conductive materials containing a cyclic carbonate and a lithium amide salt have room for improvement in lithium-ion conductivity. An electrolyte solution according to the present disclosure contains a cyclic carbonate, a lithium amide salt, and an ether compound having a repeating ether unit. Further, a lithium-ion conductive material according to the present disclosure contains a cyclic carbonate, a lithium amide salt, an ether compound having a repeating ether unit, and a polymer.

Description

Electrolytic Solution, Lithium Ion Conductive Material, Battery, and Method for Producing Lithium Ion Conductive Material

[0001] The present application discloses an electrolytic solution, a lithium ion conductive material, a battery, and a method for producing a lithium ion conductive material.

[0002] Patent Document 1 discloses an electrolytic solution containing a cyclic carbonate and a lithium amide salt. Further, Patent Document 2 discloses a lithium ion conductive material containing a composite of the electrolytic solution and a polymer.

[0003] Japanese Patent Application Laid-Open No. 2024-096618 Japanese Patent Application Laid-Open No. 2023-138137

[0004] Conventional electrolytic solutions and lithium ion conductive materials containing a cyclic carbonate and a lithium amide salt have room for improvement in terms of lithium ion conductivity.

[0005] The present application discloses the following multiple aspects as means for solving the above problems. <Aspect 1> An electrolytic solution comprising: a cyclic carbonate; a lithium amide salt; and an ether compound having a repeating ether unit. <Aspect 2> The electrolytic solution according to Aspect 1, wherein the ether compound is represented by the following formula (1): R １ -(OR ３ ) ｎ -O-R ２ (1) R １ : a hydrocarbon group having 1 to 5 carbon atoms R ２ : a hydrocarbon group having 1 to 5 carbon atoms R ３ : a hydrocarbon group having 1 to 5 carbon atoms n: an integer of 2 to 7, which is one or more compounds represented by the above. The electrolytic solution. <Aspect 3> The electrolytic solution according to Aspect 2, wherein the R １ is an alkyl group having 1 to 3 carbon atoms, and the R ２ is an alkyl group having 1 to 3 carbon atoms, and the R ３An electrolyte wherein the ether compound is an alkylene group having 2 or 3 carbon atoms, and n is an integer between 2 and 4. <Aspect 4> An electrolyte according to aspect 1, wherein the ether compound is one or more of diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, and 1-methoxy-3-(3-methoxypropoxy)propane. <Aspect 5> An electrolyte according to any of aspects 1 to 4, wherein the molar ratio of the ether compound to the cyclic carbonate (ether compound / cyclic carbonate) is greater than 0 and 1.00 or less. <Aspect 6> An electrolyte according to any of aspects 1 to 5, wherein the cyclic carbonate is one or both of propylene carbonate and ethylene carbonate. <Aspect 7> An electrolyte according to any of aspects 1 to 6, wherein the lithium amide salt is one or both of lithium bisfluorosulfonylamide and lithium bistrifluoromethanesulfonylamide. <Aspect 8> A lithium ion conductive material comprising a cyclic carbonate, a lithium amide salt, an ether compound having repeating ether units, and a polymer. <Aspect 9> A lithium ion conductive material according to aspect 8, wherein the ether compound is of the following formula (1): R １ - ( OR ３ ) ｎ -O-R ２ (1) R １ : Hydrocarbon group with 1 to 5 carbon atoms R ２ : Hydrocarbon group with 1 to 5 carbon atoms R ３ : A hydrocarbon group having 1 to 5 carbon atoms n: One or more compounds represented by an integer between 2 and 7, a lithium ion conductive material. <Aspect 10> A lithium ion conductive material according to aspect 9, wherein the R １ However, the R is an alkyl group having 1 to 3 carbon atoms. ２ However, the R is an alkyl group having 1 to 3 carbon atoms.３ A lithium ion conductive material wherein the alkylene group has 2 or 3 carbon atoms, and n is an integer between 2 and 4. <Aspect 11> A lithium ion conductive material according to Aspect 8, wherein the ether compound is one or both of triethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether. <Aspect 12> A lithium ion conductive material according to any of Aspects 8 to 11, wherein the molar ratio of the ether compound to the cyclic carbonate (ether compound / cyclic carbonate) is greater than 0 and 1.00 or less. <Aspect 13> A lithium ion conductive material according to any of Aspects 8 to 12, wherein the cyclic carbonate is one or both of propylene carbonate and ethylene carbonate. <Aspect 14> A lithium ion conductive material according to any of Aspects 8 to 13, wherein the lithium amide salt is one or both of lithium bisfluorosulfonylamide and lithium bistrifluoromethanesulfonylamide. <Aspect 15> A lithium-ion conductive material according to any of aspects 8 to 14, comprising a composite of an electrolyte and the polymer, wherein the electrolyte comprises the cyclic carbonate, the lithium amide salt, and the ether compound. <Aspect 16> A battery comprising an electrolyte according to any of aspects 1 to 7 and one or both of the lithium-ion conductive materials according to aspects 8 to 15. <Aspect 17> A method for manufacturing a lithium-ion conductive material, comprising compounding an electrolyte and a polymer, wherein the electrolyte is the electrolyte according to any of aspects 1 to 7. <Aspect 18> A method for manufacturing a lithium-ion conductive material according to aspect 17, comprising mixing the electrolyte, the polymer, and a diluent to obtain a solution, and removing the diluent from the solution to compound the electrolyte and the polymer.

[0006] The electrolyte and lithium-ion conductive material of this disclosure have high lithium-ion conductivity.

[0007] An example of a battery configuration is schematically shown. The evaluation results of lithium ion conductivity for each electrolyte in the examples and comparative examples are shown. The evaluation results of lithium ion conductivity for each lithium ion conductive material (polymer electrolyte) in the examples and comparative examples are shown. The CV test results for the electrolyte are shown. The CV test results for the electrolyte and the CV test results for the lithium ion conductive material (polymer electrolyte) are shown. The CV test results for the lithium ion conductive material (polymer electrolyte) are shown.

[0008] The following describes one embodiment of the electrolyte, lithium-ion conductive material, battery, and method for manufacturing the lithium-ion conductive material, but the technology of this disclosure is not limited to the following embodiment.

[0009] 1. Electrolyte The electrolyte according to one embodiment includes a cyclic carbonate, a lithium amide salt, and an ether compound comprising repeated ether units.

[0010] 1.1 Cyclic Carbonate The electrolyte according to this embodiment contains a cyclic carbonate. Cyclic carbonates have a higher dielectric constant than linear carbonates and readily coordinate lithium ions. In other words, cyclic carbonates are less likely to remain free in the electrolyte, and as a result, the thermal stability of the electrolyte tends to be higher. In particular, when a lithium amide salt is dissolved in the cyclic carbonate at a predetermined concentration, almost all of the cyclic carbonate can be solvated with lithium ions, and as a result, thermal stability can be further improved. Furthermore, lithium ions that are not solvated with the cyclic carbonate can increase the transport rate of lithium ions and ensure higher lithium ion conductivity.

[0011] A cyclic carbonate is any carbonate that has a cyclic structure as a chemical structure, is liquid at the temperature at which lithium ion conductivity is desired, and can dissolve lithium amide salts. In other words, the electrolyte may contain a cyclic carbonate as a solvent. As will be described later, the cyclic carbonate may be the main solvent of the electrolyte. The "main solvent" refers to the solvent with the largest molar ratio among the solvents constituting the electrolyte. Specific examples of cyclic carbonates include one or more selected from propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), vinylene carbonate (VC), and their derivatives (e.g., halides). In particular, when the cyclic carbonate is either propylene carbonate or ethylene carbonate, or both, higher lithium ion conductivity and thermal stability are more easily ensured. A single cyclic carbonate may be used alone, or two or more may be used in combination.

[0012] 1.2 Lithium amide salt The electrolyte according to this embodiment contains a lithium amide salt. The lithium amide salt is dissolved in the cyclic carbonate described above. That is, the lithium amide salt may be dissolved in the cyclic carbonate and separated into cations and anions, or it may form some kind of aggregate with the cyclic carbonate, etc.

[0013] Various amide salts can be used as lithium amide salts. In the electrolyte according to this embodiment, it is thought that lithium ions can be coordinated to the active site of the cyclic carbonate regardless of the type of lithium amide salt, and excellent thermal stability and high lithium ion conductivity can be ensured. Specific examples of lithium amide salts include lithium bisfluorosulfonylamide (LiFSA), LiN(SO4). ２ F) ２ ), lithium bistrifluoromethanesulfonylamide (LiTFSA, Li[N(CF ３ SO ２ ) ２ ]), lithium bisperfluoroethylsulfonylamide (Li[N(C ２ F５ SO ２ ) ２ ]), lithium bisperfluorobutylsulfonylamide (Li[N(C ４ F ９ SO ２ ) ２ ]), Lithium fluorosulfonyl trifluoromethanesulfonylamide (Li[N(FSO ２ ) (C ２ F ５ SO ２ Examples include at least one sulfonylamide salt selected from )]) etc. Alternatively, a silylamide salt having Si instead of S in the above amide salt may be used. In particular, lithium amide salts include lithium bisfluorosulfonylamide (LiFSA, LiN(SO)). ２ F) ２ ), and lithium bistrifluoromethanesulfonylamide (LiTFSA, Li[N(CF ３ SO ２ ) ２ If at least one of the following is true, higher lithium ion conductivity and thermal stability are more easily ensured. Lithium amide salts may be used alone or in combination of two or more types. In this application, "amide salt" is a concept that also includes "imide salt".

[0014] The molar ratio of lithium amide salt to cyclic carbonate (lithium amide salt / cyclic carbonate) is not particularly limited and can be appropriately determined according to the desired performance of the electrolyte. For example, the molar ratio of lithium amide salt to cyclic carbonate (lithium amide salt / cyclic carbonate) may be 0.20 to 0.35, 0.23 to 0.34, or greater than 0.25 and less than or equal to 0.33. When the concentration of lithium amide salt in the cyclic carbonate is within this range, the thermal stability and lithium ion conductivity of the electrolyte tend to improve more significantly. The molar ratio of lithium amide salt to cyclic carbonate in the electrolyte can be determined by analyzing the components, ions, and elements that make up the electrolyte.

[0015] 1.3 Ether Compounds with Repeating Ether Units The electrolyte according to this embodiment includes ether compounds having repeating ether units. "Ether compounds with repeating ether units" means compounds that have three or more ether bonds as a whole, and have two or more units represented by -R-O- as repeating units constituting the compound. R may be, for example, a hydrocarbon group. The R in one repeating unit and the R in another repeating unit may be the same or different, but a higher effect is more likely to be exhibited when they are the same. In the electrolyte, the ether compound is thought to exhibit a function of selectively transporting lithium ions due to its regular structure containing ether groups. As a result, the electrolyte has high lithium ion conductivity.

[0016] An ether compound having repeating ether units is a compound having repeating ether units as a chemical structure, and may be a liquid or a solid at the temperature at which lithium ion conductivity is to be exhibited. If the ether compound is a solid, it is sufficient that the solid ether compound is dissolved in the cyclic carbonate described above. If the ether compound is a liquid, it is sufficient that the liquid ether compound is mixed with the cyclic carbonate described above. As will be described later, the ether compound may function as a solvent in the electrolyte together with the cyclic carbonate. That is, the electrolyte may contain the ether compound as a solvent, and as will be described later, it may also contain the ether compound as a secondary solvent. The ether compound may be used alone or in combination of two or more types.

[0017] The ether compound comprising repeating ether units may be one or more compounds represented by the following formula (1): R １ - ( OR ３ ) ｎ -O-R ２ (1) R １ : Hydrocarbon group with 1 to 5 carbon atoms R ２: Hydrocarbon group with 1 to 5 carbon atoms R ３ : Hydrocarbon group with 1 to 5 carbon atoms n: Integer between 2 and 7 carbon atoms

[0018] In the above formula (1), R １ R is a hydrocarbon group having 1 to 5 carbon atoms. １ It is thought that having five or fewer carbon atoms facilitates interaction between the ether bond and lithium ions, thereby enhancing the function of selectively transporting lithium ions. １ The number of carbon atoms may be 1 to 4, 1 to 3, or 1 or 2. １ R may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. １ R may be a straight-chain hydrocarbon group or a branched hydrocarbon group. １ This is R, which will be discussed later. ２ They may combine to form a ring. １ This may be an alkyl group having 1 to 3 carbon atoms (i.e., a methyl group, an ethyl group, a 1-propyl group (n-propyl group), or a 2-propyl group (isopropyl group)).

[0019] In the above formula (1), R ２ R is a hydrocarbon group having 1 to 5 carbon atoms. ２ It is thought that having five or fewer carbon atoms facilitates interaction between the ether bond and lithium ions, thereby enhancing the function of selectively transporting lithium ions. ２ The number of carbon atoms may be 1 to 4, 1 to 3, or 1 or 2. ２ R may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. ２ R may be a straight-chain hydrocarbon group or a branched hydrocarbon group. ２ The above R １ They may combine to form a ring. ２ This may be an alkyl group having 1 to 3 carbon atoms (i.e., a methyl group, an ethyl group, a 1-propyl group (n-propyl group), or a 2-propyl group (isopropyl group)).

[0020] In the above formula (1), R ３ R is a hydrocarbon group having 1 to 5 carbon atoms. ３ It is thought that having five or fewer carbon atoms facilitates interaction between the ether bond and lithium ions, thereby enhancing the function of selectively transporting lithium ions. ３ The number of carbon atoms may be 1 or more and 4 or less, 2 or more and 4 or less, or 2 or 3. ３ R may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. ３ R may be a straight-chain hydrocarbon group or a branched hydrocarbon group. ３ This may be an alkylene group having 2 or 3 carbon atoms (i.e., an ethylene group or a propylene group (1,2-propylene group, 2,3-propylene group, and / or 1,3-propylene group)).

[0021] In the above formula (1), n ​​is an integer between 2 and 7. When n is 7 or less, the lithium ion conductivity of the electrolyte is more easily increased. n may also be between 2 and 6, between 2 and 5, or between 2 and 4.

[0022] In particular, the lithium ion conductivity of the electrolyte tends to increase more significantly when the ether compound comprising repeating ether units is one or more of the following: diethylene glycol dimethyl ether (diglyme, G2), triethylene glycol dimethyl ether (triglyme, G3), tetraethylene glycol dimethyl ether (tetraglyme, G4), dipropylene glycol dimethyl ether (DPGDME), and 1-methoxy-3-(3-methoxypropoxy)propane (1M33MPP). In one embodiment, the ether compound may contain diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, or 1-methoxy-3-(3-methoxypropoxy)propane. Note that "dipropylene glycol dimethyl ether" refers to R in formula (1) above.１ and R ２ is a methyl group, R ３ This refers to a compound in which is an isopropylene group (1,2-propylene group and / or 2,3-propylene group) and n is 2, specifically one or more compounds represented by the following formulas (2-1) to (2-3). On the other hand, "1-methoxy-3-(3-methoxypropoxy)propane" refers to a compound in which R in formula (1) above is 2. １ and R ２ is a methyl group, R ３ This refers to a compound in which n is an n-propylene group (1,3-propylene group) and n is 2, specifically the compound represented by the following formula (3).

[0023] The molar ratio of the ether compound having repeating ether units to the cyclic carbonate (ether compound / cyclic carbonate) is not particularly limited and can be appropriately determined according to the performance of the target electrolyte. In particular, the lithium ion conductivity of the electrolyte tends to be higher when the molar ratio of the ether compound to the cyclic carbonate (ether compound / cyclic carbonate) is greater than 0 and less than or equal to 1.00. For example, when both the cyclic carbonate and the ether compound are liquids, the cyclic carbonate may be the main solvent and the ether compound may be the secondary solvent. The molar ratio (ether compound / cyclic carbonate) is as follows: greater than 0 and less than 1.00, greater than 0 and 0.95 or less, greater than 0 and 0.90 or less, greater than 0 and 0.85 or less, greater than 0 and 0.80 or less, greater than 0 and 0.75 or less, greater than 0 and 0.70 or less, greater than 0 and 0.65 or less, greater than 0 and 0.60 or less, greater than 0 and 0.55 or less, greater than 0 and 0.50 or less, greater than 0 and 0.45 or less, greater than 0 and 0.40 or less, greater than 0 and 0.35 or less, 0.05 or more and 1.00 or less, 0.05 or more and less than 1.00, 0 The molar ratio of the ether compound to the cyclic carbonate in the electrolyte can be determined by analyzing the components that make up the electrolyte.

[0024] The molar ratio of the ether compound containing repeating ether units to the lithium amide salt (ether compound / lithium amide salt) is not particularly limited and can be appropriately determined according to the performance of the target electrolyte. In particular, when the molar ratio of the ether compound to the lithium amide salt (ether compound / lithium amide salt) is greater than 0 and 3.00 or less, the lithium ion conductivity of the electrolyte tends to be higher. The molar ratio (ether compound / lithium amide salt) may be greater than 0 and 2.75 or less, greater than 0 and 2.50 or less, greater than 0 and 2.25 or less, greater than 0 and 2.00 or less, 0.05 or more and 3.00 or less, 0.05 or more and 2.75 or less, 0.05 or more and 2.50 or less, 0.05 or more and 2.25 or less, or 0.05 or more and 2.00 or less. The molar ratio of the ether compound to the lithium amide salt in the electrolyte can be determined by analyzing the components, ions, elements, etc. that make up the electrolyte.

[0025] 1.4 Other Components The electrolyte may contain other components in addition to the cyclic carbonate, lithium amide salt, and ether compound comprising repeated ether units described above. Examples of other components include auxiliary solvents other than cyclic carbonates and ether compounds, and lithium salts other than lithium amide salts. The electrolyte may also contain various additives.

[0026] The electrolyte may, for example, contain a linear carbonate as a secondary solvent. Examples of linear carbonates include at least one selected from dimethyl carbonate (DMC), diethyl carbonate (DEC), and their derivatives (e.g., halides, especially those having perfluoroalkyl groups). However, linear carbonates have a lower dielectric constant compared to cyclic carbonates, and lithium ions tend to be less likely to coordinate with them. Therefore, linear carbonates tend to be free on their own in the electrolyte and are easily volatile. In this respect, higher thermal stability is more easily ensured when the amount of linear carbonate in the electrolyte is small. In the electrolyte, the molar ratio of other secondary solvents to the total of the cyclic carbonate and the ether compound having repeating ether units (other secondary solvents / (cyclic carbonate + ether compound)) may be 0 to 0.10, 0 to 0.05, 0 to 0.03, or 0 to 0.01.

[0027] In the electrolyte, the lithium salt dissolved in the solvent may consist of the above-mentioned lithium amide salt, or it may be a combination of the above-mentioned lithium amide salt and a lithium salt other than the lithium amide salt (other lithium salt). In any case, the combination of a cyclic carbonate, a lithium amide salt, and an ether compound having repeating ether units makes it easier to ensure excellent thermal stability and high lithium ion conductivity. In the electrolyte, it is preferable that the proportion of lithium amide salt in the lithium salt dissolved in the solvent is high. Specifically, the proportion of lithium amide salt in the total lithium salt (100 mol%) may be 50 mol% to 100 mol%, 60 mol% to 100 mol%, 70 mol% to 100 mol%, 80 mol% to 100 mol%, 90 mol% to 100 mol%, 95 mol% to 100 mol%, or 99 mol% to 100 mol%.

[0028] 2. Method for Producing an Electrolyte One embodiment of the method for producing an electrolyte includes, for example, mixing a cyclic carbonate, a lithium amide salt, and an ether compound comprising repeated ether units. In one embodiment, the electrolyte can be obtained by dissolving the lithium amide salt in a cyclic carbonate as a solvent and mixing it with the ether compound as a solvent. The mixing ratio of each component may be as described above. The means for mixing each component is not particularly limited.

[0029] 3. Lithium-ion conductive material One embodiment of the lithium-ion conductive material includes a cyclic carbonate, a lithium amide salt, an ether compound having repeating ether units, and a polymer. For example, the lithium-ion conductive material includes a composite of an electrolyte and a polymer, and the electrolyte may include a cyclic carbonate, a lithium amide salt, and an ether compound having repeating ether units.

[0030] 3.1 Cyclic Carbonate The cyclic carbonate is the same as the exemplified cyclic carbonate constituting the electrolyte according to this embodiment. For example, the cyclic carbonate may be propylene carbonate and / or ethylene carbonate. The type and content of the cyclic carbonate are as described above, and a detailed explanation is omitted here.

[0031] 3.2 Lithium Amide Salt The lithium amide salt is the same as the lithium amide salt exemplified as constituting the electrolyte according to this embodiment. For example, the lithium amide salt may be one or both of lithium bisfluorosulfonylamide and lithium bistrifluoromethanesulfonylamide. The type and content of the lithium amide salt are as described above, and a detailed explanation is omitted here.

[0032] 3.3 Ether Compounds Equipped with Repeating Ether Units The ether compounds equipped with repeating ether units are the same as those exemplified as ether compounds equipped with repeating ether units constituting the electrolyte according to this embodiment. For example, the ether compounds equipped with repeating ether units may be one or more compounds represented by the following formula (1). In the following formula (1), R １ R may be an alkyl group having 1 to 3 carbon atoms, ２ R may be an alkyl group having 1 to 3 carbon atoms, ３ n may be an alkylene group having 2 or 3 carbon atoms, and n may be an integer between 2 and 4. Furthermore, the ether compound may be one or more of diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, and 1-methoxy-3-(3-methoxypropoxy)propane. Also, the ether compound may be one or both of triethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether. Furthermore, the molar ratio of the ether compound to the cyclic carbonate (ether compound / cyclic carbonate) may be greater than 0 and less than or equal to 1.00. The types and content of the ether compound are as described above, and a detailed explanation is omitted here. R １ - ( OR ３ ) ｎ -O-R ２ (1) R １ : Hydrocarbon group with 1 to 5 carbon atoms R ２ : Hydrocarbon group with 1 to 5 carbon atoms R ３ : Hydrocarbon group with 1 to 5 carbon atoms n: Integer between 2 and 7 carbon atoms

[0033] 3.4 Polymer According to the inventors' knowledge, by compounding each of the above components (for example, the electrolyte) with a polymer, a lithium-ion conductive material is obtained that has high lithium-ion conductivity and excellent electrochemical stability (for example, oxidation stability). When a battery is constructed using such a lithium-ion conductive material, even if the battery is repeatedly charged and discharged, decomposition of the lithium-ion conductive material and corrosion of the current collector are unlikely to occur. Furthermore, when a battery is constructed using the lithium-ion conductive material according to this embodiment, even if the battery is repeatedly charged and discharged, CEIs that inhibit lithium-ion insertion and removal are unlikely to form on the surface of the active material, etc., resulting in a good interface between the lithium-ion conductive material and the active material, and making it easier to obtain excellent lithium-ion input / output characteristics.

[0034] There are no particular restrictions on the type of polymer; any polymer that can be compounded with each of the above components (e.g., the electrolyte) can be used. The polymer may be a fluoride-based polymer or a non-fluoride-based polymer. Fluoride-based polymers have the advantage of low reactivity to various battery materials (e.g., sulfide solid electrolytes). On the other hand, non-fluoride-based polymers have the advantage of tending to have higher affinity with each of the above components (e.g., the electrolyte) compared to fluoride-based polymers.

[0035] The fluoride polymer may be at least one selected from polyvinylidene fluoride (PVdF) polymers, polytetrafluoroethylene (PTFE) polymers, etc. These fluoride polymers may be homopolymers obtained by polymerizing a single monomer alone, or they may be copolymers containing polymerization units derived from other monomers such as hexafluoropropylene. In the fluoride polymer, 50 mol% to 100 mol%, 60 mol% to 100 mol%, 70 mol% to 100 mol%, 80 mol% to 100 mol%, 90 mol% to 100 mol%, or 95 mol% to 100 mol% of the total polymerization units may be derived from fluoride monomers.

[0036] The non-fluoride polymer may be an ether polymer or a non-ether polymer. The ether polymer may be at least one selected from polyethylene oxide, polypropylene oxide, etc. The non-ether polymer may be at least one selected from butadiene rubber (BR), butylene rubber (IIR), acrylate butadiene rubber, or styrene butadiene rubber (SBR), polyimide (PI), and polyacrylic acid, etc. These non-fluoride polymers may be homopolymers obtained by polymerizing one monomer alone, or copolymers that include polymerization units derived from other monomers. In the non-fluoride polymer, 50 mol% to 100 mol%, 60 mol% to 100 mol%, 70 mol% to 100 mol%, 80 mol% to 100 mol%, 90 mol% to 100 mol%, or 95 mol% to 100 mol% of the total polymerization units may be derived from non-fluoride monomers.

[0037] The molecular weight of the polymer is not particularly limited. If the polymer constituting the lithium-ion conductive material has a molecular weight above a certain level, the lithium-ion conductive material as a whole tends to lose its fluidity (viscosity of 10,000 mPa·s or more at 25°C). From this viewpoint, the weight-average molecular weight of the polymer may be, for example, between 30,000 and 3,000,000. The weight-average molecular weight of the polymer may be between 100,000 and 500,000 or 2,000,000 or 1,000,000. Note that the weight-average molecular weight of the polymer is a value based on gel permeation chromatography (GPC).

[0038] 3.5 Mixing Ratio (Mass Ratio) The mixing ratio (mass ratio) of each of the above components (for example, the electrolyte) to the polymer is not particularly limited. For the above polymer and the above electrolyte to become one unit and the lithium ion conductive material as a whole to have no fluidity (viscosity of 10,000 mPa·s or more at 25°C), for example, the mass M of the electrolyte constituting the lithium ion conductive material １ and the mass M of the polymer２ total M with １ + M ２ mass M of the polymer relative to ２ ratio M ２ / (M １ + M ２ ) is preferably 0.10 or more and 0.50 or less. The ratio M ２ / (M １ + M ２ ) may be 0.15 or more, or 0.20 or more, and may be 0.40 or less, or 0.30 or less. The mass ratio of the electrolyte solution to the polymer in the lithium ion conductive material can be specified by analyzing components, ions, elements and the like constituting the lithium ion conductive material.

[0039] 3.6 Viscosity The viscosity at 25°C of the lithium ion conductive material according to the present embodiment may be 10000 mPa·s or more, 50000 mPa·s or more, or 100000 mPa·s or more. The upper limit of the viscosity is not particularly limited. The lithium ion conductive material may be solid at 25°C. The viscosity of the lithium ion conductive material can be measured at 25°C using a rheometer (manufactured by Thermo Scientific).

[0040] 3.7 Morphology of Lithium-Ion Conducting Material As described above, the lithium-ion conducting material according to this embodiment may include a composite of the electrolyte and the polymer. In one embodiment of the lithium-ion conducting material, the electrolyte may be held by the polymer. In one embodiment of the lithium-ion conducting material, the viscosity of the electrolyte may be increased by the polymer. In one embodiment of the lithium-ion conducting material, the polymer and the electrolyte may be integrated together, and the lithium-ion conducting material as a whole may not have fluidity (viscosity of 10,000 mPa·s or more at 25°C). In one embodiment of the lithium-ion conducting material, when the lithium-ion conducting material is used, there may be substantially no electrolyte released from the lithium-ion conducting material to the outside of the lithium-ion conducting material (the amount of electrolyte that can be released to the outside of the lithium-ion conducting material is 0.1% by mass or less of the total electrolyte contained in the lithium-ion conducting material). In one embodiment of the lithium-ion conducting material, it may be a solid at 25°C.

[0041] As described above, the lithium-ion conductive material according to this embodiment may not be fluid as a whole, that is, it may be shape-retaining. In one embodiment, the lithium-ion conductive material may be, for example, in the form of a sheet or in the form of a powder. Alternatively, the lithium-ion conductive material may be a composite of the above-mentioned components (for example, the electrolyte) and a polymer, which is integrated with another material. In one embodiment, the lithium-ion conductive material may be a composite integrated with a solid electrolyte. More specifically, for example, at least a portion of the surface of solid electrolyte particles may be coated with the composite. In one embodiment, the lithium-ion conductive material may be a composite integrated with an active material. More specifically, at least a portion of the surface of active material particles may be coated with the composite. The solid electrolyte and active material will be described later.

[0042] 3.8 Other Components The lithium-ion conductive material according to this embodiment may contain other components in addition to the cyclic carbonate, lithium amide salt, ether compound comprising repeated ether units, and polymer described above. Examples of other components include auxiliary solvents other than the cyclic carbonate and ether compound, and lithium salts other than the lithium amide salt. The lithium-ion conductive material may also contain various additives. The type of additive can be selected according to the application of the lithium-ion conductive material. The other components may be the same as those exemplified as other components constituting the electrolyte according to this embodiment.

[0043] Furthermore, as described above, the lithium-ion conductive material according to this embodiment may be integrated with other materials such as solid electrolytes and active materials. For example, the lithium-ion conductive material according to this embodiment may include a sulfide solid electrolyte in addition to the composite of each of the above-mentioned components (electrolyte) and polymer. In the combination of the composite and the sulfide solid electrolyte, for example, the composite may fill the gaps between the sulfide solid electrolytes. That is, ion conduction paths can be formed even in the gaps of the sulfide solid electrolyte. Also, in the combination of the composite and the sulfide solid electrolyte, for example, the composite may function as a binder that binds the sulfide solid electrolytes together, or the sulfide solid electrolyte to other materials. When combining the above-mentioned composite with a sulfide solid electrolyte, it is preferable to suppress the reaction between the composite and the sulfide solid electrolyte. Specifically, in the combination of the composite and the sulfide solid electrolyte, at least one of the following (1) to (3) may be satisfied, two or more of (1) to (3) may be satisfied, or all of (1) to (3) may be satisfied. (1) The electrolyte constituting the composite contains only a cyclic carbonate and an ether compound as a solvent, or contains a cyclic carbonate and an ether compound and other solvents, and the molar ratio of other auxiliary solvents to the total of the cyclic carbonate and ether compounds (other auxiliary solvents / (cyclic carbonate + ether compound)) is 0.10 or less, 0.05 or less, 0.03 or less, or 0.01 or less. (2) The proportion of lithium amide salt in the total lithium salt (100 mol%) contained in the electrolyte constituting the composite is 50 mol% or more, 60 mol% or more, 70 mol% or more, 80 mol% or more, 90 mol% or more, 95 mol% or more, or 99 mol% or more, and the lithium amide salt is at least one of lithium bisfluorosulfonylamide (LiFSA) and lithium bistrifluoromethanesulfonylamide (LiTFSA). (3) The polymer is a fluoride-based polymer.

[0044] The sulfide solid electrolyte may be a glass-based sulfide solid electrolyte (sulfide glass), a glass-ceramic-based sulfide solid electrolyte, or a crystalline sulfide solid electrolyte. The sulfide glass is amorphous. The sulfide glass may have a glass transition temperature (Tg). Furthermore, if the sulfide solid electrolyte has a crystalline phase, examples of the crystalline phase include the Thio-LISICON type crystalline phase, the LGPS type crystalline phase, and the argyrodite type crystalline phase.

[0045] The sulfide solid electrolyte may contain, for example, Li, X (where X is at least one of P, As, Sb, Si, Ge, Sn, B, Al, Ga, and In), and S. The sulfide solid electrolyte may further contain at least one of O and halogen elements. Furthermore, the sulfide solid electrolyte may contain S as the main component of the anionic element.

[0046] Sulfide solid electrolytes include, for example, Li ２ S-P ２ S ５ Li ２ S-P ２ S ５ -LiI, Li ２ S-P ２ S ５ -GeS ２ Li ２ S-P ２ S ５ -Li ２ O, Li ２ S-P ２ S ５ -Li ２ O-LiI, Li ２ S-P ２ S ５ -LiI-LiBr, Li ２ S-SiS ２ Li ２ S-SiS ２ -LiI, Li ２ S-SiS ２ - LiBr, Li ２ S-SiS ２ -LiCl, Li ２ S-SiS ２ -B ２S ３ -LiI, Li ２ S-SiS ２ -P ２ S ５ -LiI, Li ２ S-B ２ S ３ Li ２ S-P ２ S ５ -ZmSn (where m and n are positive numbers, and Z is one of Ge, Zn, or Ga), Li ２ S-GeS ２ Li ２ S-SiS ２ -Li ３ PO ４ Li ２ S-SiS ２ -Li ｘ MO ｙ (wherein x and y are positive numbers, and M is one of P, Si, Ge, B, Al, Ga, or In.) It may be at least one selected from these.

[0047] The composition of the sulfide solid electrolyte is not particularly limited, but for example, xLi ２ S・(100-x)P ２ S ５ (70≦x≦80), yLiI・zLiBr・(100−y−z)(xLi ２ S・(1-x)P ２ S ５ Examples include (0.7 ≤ x ≤ 0.8, 0 ≤ y ≤ 30, 0 ≤ z ≤ 30). Alternatively, a sulfide solid electrolyte has the general formula: Li ４－ｘ Ge １－ｘ P ｘ S ４It may have a composition represented by (0 < x < 1). In the above general formula, at least a portion of Ge may be substituted with at least one of Sb, Si, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb. In the above general formula, at least a portion of P may be substituted with at least one of Sb, Si, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb. In the above general formula, a portion of Li may be substituted with at least one of Na, K, Mg, Ca, and Zn. In the above general formula, a portion of S may be substituted with a halogen (at least one of F, Cl, Br, and I). Alternatively, the sulfide solid electrolyte may be Li ７－ａ PS ６－ａ X ａ The composition may be represented by (X is at least one of Cl, Br, and I, and a is a number between 0 and 2). a may be 0 or greater than 0. In the latter case, a may be 0.1 or greater, 0.5 or greater, or 1 or greater. Also, a may be 1.8 or less, or 1.5 or less.

[0048] The sulfide solid electrolyte may be in particulate form. The average particle size (D50) of the sulfide solid electrolyte may be, for example, 10 nm or more and 100 μm or less. In this application, the average particle size D50 refers to the particle size (median diameter) at 50% of the cumulative value in the volume-based particle size distribution determined by laser diffraction and scattering.

[0049] 4. Method for Manufacturing Lithium-Ion Conducting Materials The lithium-ion conducting material according to this embodiment can be manufactured, for example, by the following method. That is, the method for manufacturing the lithium-ion conducting material according to this embodiment includes compounding an electrolyte with a polymer. Here, the electrolyte is the electrolyte according to this embodiment described above. That is, the electrolyte includes a cyclic carbonate, a lithium amide salt, and an ether compound comprising repeating ether units.

[0050] Simply mixing an electrolyte and a polymer may not result in sufficient affinity between the electrolyte and the polymer, causing them to separate. In this embodiment, some ingenuity is needed to compound the electrolyte and the polymer. For example, when mixing the electrolyte and the polymer, a diluent may be used to increase the affinity between the electrolyte and the polymer. That is, the method for producing the lithium-ion conductive material according to this embodiment may include mixing the electrolyte, the polymer, and a diluent to obtain a solution, and then compounding the electrolyte and the polymer by removing the diluent from the solution. The diluent should be capable of dissolving both the electrolyte and the polymer. The diluent can also be considered a compatibilizer to improve the compatibility between the electrolyte and the polymer. Furthermore, if the boiling point of the diluent is lower than the boiling point of the solvent constituting the electrolyte (cyclic carbonate, ether compound having repeating ether units), it is considered that the diluent can be removed more easily by heating. The diluent may be, for example, a linear carbonate. Specifically, the diluent may be dimethyl carbonate. The mixing ratio of the electrolyte, polymer, and diluent is not particularly limited. When mixing the electrolyte, polymer, and diluent, heating may or may not be performed.

[0051] 5. Battery The electrolyte and lithium-ion conductive material described above are used, for example, as the electrolyte of a battery. That is, the battery according to this embodiment includes one or both of the electrolyte and lithium-ion conductive material according to the embodiment described above. As shown in Figure 1, a battery 100 according to one embodiment includes a positive electrode active material layer 20, an electrolyte layer 30, and a negative electrode active material layer 40. Here, at least one of the positive electrode active material layer 20, the electrolyte layer 30, and the negative electrode active material layer 40 includes one or both of the electrolyte and lithium-ion conductive material according to the embodiment described above. Also, as shown in Figure 1, the battery 100 may include a positive electrode current collector 10 that is in contact with the positive electrode active material layer 20. Also, as shown in Figure 1, the battery 100 may include a negative electrode current collector 50 that is in contact with the negative electrode active material layer 40.

[0052] 5.1 Positive electrode current collector The battery 100 may include a positive electrode current collector 10 that is in contact with the positive electrode active material layer 20. Any of the positive electrode current collectors commonly used for batteries can be used as the positive electrode current collector 10. The positive electrode current collector 10 may also have at least one shape selected from sheet (foil, plate), mesh, perforated metal, and foam. The positive electrode current collector 10 may be made of metal foil or metal mesh. The positive electrode current collector 10 may be made of a resin composition containing a conductive material and resin. The positive electrode current collector 10 may consist of multiple foils. Examples of metals that make up the positive electrode current collector 10 include at least one selected from Cu, Ni, Cr, Au, Pt, Ag, Al, Fe, Ti, Zn, Co, V, Mg, Pb, Ge, In, Sn, Zr, and stainless steel. In particular, the positive electrode current collector 10 may contain Al from the viewpoint of ensuring oxidation resistance, etc. The positive electrode current collector 10 may have some kind of coating layer on its surface for the purpose of adjusting resistance, etc. For example, the positive electrode current collector 10 may have a carbon coating layer. The positive electrode current collector 10 may also be a metal foil or substrate on which the above metal has been plated or deposited. Furthermore, if the positive electrode current collector 10 consists of a plurality of metal foils, there may be some kind of layer between the plurality of metal foils. The thickness of the positive electrode current collector 10 is not particularly limited. For example, it may be 0.1 μm or more or 1 μm or more, or 1 mm or less or 100 μm or less.

[0053] 5.2 The positive electrode active material layer battery 100 comprises a positive electrode active material layer 20. The positive electrode active material layer 20 contains at least a positive electrode active material. The positive electrode active material layer 20 may also optionally contain an electrolyte, a conductive additive, a binder, and various additives. If the positive electrode active material layer 20 contains the electrolyte and / or lithium ion conductive material according to the above embodiment, the positive electrode active material layer 20 may further optionally contain other electrolytes, conductive additives, binders, and various additives in addition to the positive electrode active material and the electrolyte and / or lithium ion conductive material. The content of each component in the positive electrode active material layer 20 may be appropriately determined according to the desired battery performance. For example, with the total solid content of the positive electrode active material layer 20 being 100% by mass, the content of the positive electrode active material may be 40% by mass or more, 50% by mass or more, 60% by mass or more, or 70% by mass or more, or 100% by mass or less, less than 100% by mass, 95% by mass or less, or 90% by mass or less. Alternatively, with the total volume of the positive electrode active material layer 20 being 100% by volume, the positive electrode active material and optionally an electrolyte, conductive additive, and binder may together be 85% by volume or more, 90% by volume or more, or 95% by volume or more, with the remainder being void or other components. The shape of the positive electrode active material layer 20 is not particularly limited, and for example, it may be a sheet with a substantially flat surface. The thickness of the positive electrode active material layer 20 is not particularly limited, and for example, it may be 0.1 μm or more, 1 μm or more, 10 μm or more, or 30 μm or more, or 2 mm or less, 1 mm or less, 500 μm or less, or 100 μm or less.

[0054] 5.2.1 Positive Electrode Active Material Any known positive electrode active material for batteries can be used as the positive electrode active material. Among the known active materials, a material with a relatively noble potential for intercalating and releasing lithium ions (charge / discharge potential) can be used as the positive electrode active material, and a material with a relatively noble potential can be used as the negative electrode active material described below. The positive electrode active material may be, for example, at least one selected from various lithium-containing compounds, elemental sulfur, and sulfur compounds. The lithium-containing compound used as the positive electrode active material may be a lithium-containing oxide containing at least one element M, Li, and O. Element M may be, for example, at least one selected from Mn, Ni, Co, Al, Mg, Ca, Sc, V, Cr, Cu, Zn, Ga, Ge, Y, Zr, Sn, Sb, W, Pb, Bi, Fe, and Ti, or at least one selected from the group consisting of Mn, Ni, Co, Al, Fe, and Ti. More specifically, lithium-containing oxides include lithium cobaltate, lithium nickelate, lithium manganeseate, lithium nickel cobaltate, lithium nickel manganeseate, lithium cobalt manganeseate, and lithium nickel cobalt manganeseate (Li １±α Ni ｘ Co ｙ Mn ｚ O ２±δ (For example, 0 < x < 1, 0 < y < 1, 0 < z < 1, x + y + z = 1), spinel-type lithium compounds (Li １＋ｘ Mn ２－ｘ－ｙ M ｙ O ４ (For example, Li-Mn spinel with heterogeneous element substitution, where M is one or more selected from Al, Mg, Co, Fe, Ni, and Zn), lithium nickel-cobalt aluminate (e.g., Li １±α Ni ｐ Co ｑ Al ｒ O ２±δ (For example, p + q + r = 1), lithium titanate, lithium metallic phosphate (LiMPO ４The positive electrode active material may be at least one selected from the following (where M is one or more selected from Fe, Mn, Co, and Ni). In particular, the performance of the battery tends to be further improved when the positive electrode active material contains a lithium-containing oxide as a constituent element, which includes at least one of Ni, Co, and Mn, as well as Li and O. Alternatively, the performance of the battery tends to be further improved when the positive electrode active material contains a lithium-containing oxide as a constituent element, which includes at least one of Ni, Co, and Al, as well as Li and O. The positive electrode active material may be used alone or in combination of two or more types.

[0055] The shape of the positive electrode active material may be any shape that is common for positive electrode active materials in batteries. The positive electrode active material may be particulate, for example. The positive electrode active material may have voids, for example, it may be porous or hollow. The positive electrode active material may be primary particles or secondary particles formed by the aggregation of multiple primary particles. The average particle diameter D50 of the positive electrode active material may be, for example, 1 nm or more, 5 nm or more, or 10 nm or more, and may also be 500 μm or less, 100 μm or less, 50 μm or less, or 30 μm or less. Note that the average particle diameter D50 of the positive electrode active material is the particle diameter (median diameter) at 50% of the cumulative value in the volume-based particle size distribution determined by laser diffraction and scattering.

[0056] 5.2.2 Protective Layer An ion-conductive protective layer may be formed on the surface of the positive electrode active material. That is, the positive electrode active material layer 20 may include a composite of the positive electrode active material and the protective layer, and in the composite, at least a portion of the surface of the positive electrode active material may be covered by the protective layer. This makes it easier to suppress reactions between the positive electrode active material and other battery materials (such as the sulfide solid electrolyte described later). The ion-conductive protective layer may include various ion-conductive compounds. The ion-conductive compound may be at least one selected from, for example, ion-conductive oxides and ion-conductive halides.

[0057] The ion-conducting oxide may, for example, contain at least one element selected from B, C, Al, Si, P, S, Ti, La, Zr, Nb, Mo, Zn, and W, as well as Li and O. The ion-conducting oxide may also be an oxynitride containing N. More specifically, the ion-conducting oxide may contain Li ３ BO ３ LiBO ２ Li ２ CO ３ LiAlO ２ Li ４ SiO ４ Li ２ SiO ３ Li ３ PO ４ Li ２ SO ４ Li ２ TiO ３ Li ４ Ti ５ O １２ Li ２ Ti ２ O ５ Li ２ ZrO ３ LiNbo ３ Li ２ MoO ４ Li ２ WO ４ ,LiPON,Li ２ O-LaO ２ Li ２ O-ZnO ２ It may be at least one selected from the above. The ion-conducting oxide may have some elements substituted with various doping elements.

[0058] The ion-conducting halide may be, for example, at least one of the various compounds exemplified as halide solid electrolytes described later. The ion-conducting halide may include, for example, at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Zn, Sn, Al, Sc, Ga, Bi, Sb, Zr, Hf, Ti, Ta, Nb, W, Y, Gd, Tb, and Sm, at least one halogen element selected from the group consisting of Cl, Br, I, and F, and Li. The ion-conducting halide may include at least one element selected from the group consisting of Ti and Al, at least one element selected from the group consisting of Cl, Br, I, and F, and Li. Furthermore, the ionic conductive halide may be, for example, a composite halide of Li, Ti, Al, and F.

[0059] The coverage rate (area ratio) of the protective layer on the surface of the positive electrode active material may be, for example, 70% or more, 80% or more, or 90% or more. The thickness of the protective layer may be, for example, 0.1 nm or more, 1 nm or more, 100 nm or less, or 20 nm or less.

[0060] 5.2.3 The electrolyte positive electrode active material layer 20 may contain an electrolyte. The electrolyte that may be contained in the positive electrode active material layer 20 may be an electrolyte according to the above embodiment, a lithium ion conductive material according to the above embodiment, another solid electrolyte, another liquid electrolyte, or a combination thereof.

[0061] 5.2.3.1 Solid Electrolyte As the solid electrolyte, any known solid electrolyte for batteries may be used. The solid electrolyte other than the lithium-ion conductive material according to the above embodiment may be an inorganic solid electrolyte or an organic polymer electrolyte. In particular, inorganic solid electrolytes have excellent ionic conductivity and heat resistance. Examples of inorganic solid electrolytes include oxide solid electrolytes, sulfide solid electrolytes, and ionically bonded inorganic solid electrolytes. Among inorganic solid electrolytes, sulfide solid electrolytes, and among those, sulfide solid electrolytes containing at least Li, S, and P as constituent elements, exhibit high performance. Alternatively, among inorganic solid electrolytes, ionically bonded solid electrolytes, and among those, solid electrolytes containing at least Li, Y, and a halogen (at least one of Cl, Br, I, and F) as constituent elements, exhibit high performance. The solid electrolyte may be amorphous or crystalline. The solid electrolyte may be particulate. The average particle size (D50) of the solid electrolyte may be, for example, 10 nm or more and 10 μm or less. The ionic conductivity of the solid electrolyte at 25°C is, for example, 1 × 10⁻⁶ －５ S / cm or more, 1×10 －４ S / cm or more, or 1 x 10 －３ The S / cm ratio may be higher. The solid electrolyte may be used alone or in combination of two or more types.

[0062] Oxide solid electrolytes include lithium lanthanum zirconate, LiPON, and Li １＋Ｘ Al Ｘ Ge ２－Ｘ (PO ４ ) ３ It may be one or more types selected from Li-SiO glass, Li-Al-S-O glass, etc. Furthermore, when an oxide solid electrolyte and a liquid electrolyte are combined, ionic conductivity may be improved.

[0063] The sulfide solid electrolyte is as described above.

[0064] The ionic solid electrolyte may contain, for example, at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Zn, Sn, Al, Sc, Ga, Bi, Sb, Zr, Hf, Ti, Ta, Nb, W, Y, Gd, Tb, and Sm. These elements can generate cations in water. The ionic solid electrolyte material may also further contain, for example, at least one halogen element selected from the group consisting of Cl, Br, I, and F. These elements can generate anions in water. The ionic solid electrolyte may contain at least one element selected from the group consisting of Gd, Ca, Zr, and Y, at least one element selected from the group consisting of Cl, Br, I, and F, and Li. Alternatively, the ionic solid electrolyte may contain Li and Y, and at least one element selected from the group consisting of Cl, Br, I, and F. More specifically, the ionic solid electrolyte may contain Li, Y, Cl, and Br, or Li, Ca, Y, Gd, Cl, and Br, or Li, Zr, Y, and Cl. More specifically, the ionic solid electrolyte may contain Li ３ YBr ２ Cl ４ Li ２．８ Ca ０．１ Y ０．５ Gd ０．５ Br ２ Cl ４ , and Li ２．５ Y ０．５ Zr ０．５ Cl ６ It may be at least one of the following.

[0065] The ionic solid electrolyte may be a halide solid electrolyte. Halide solid electrolytes have excellent ionic conductivity. For example, a halide solid electrolyte is given by formula (A): Li α M β X γ...The composition may be as shown in (A). Here, α, β, and γ are each independently greater than 0, M is at least one selected from the group consisting of metallic elements other than Li and metalloid elements, and X is at least one selected from the group consisting of Cl, Br, and I. The "metalloid element" may be at least one selected from the group consisting of B, Si, Ge, As, Sb, and Te. The "metal element" may also include (i) all elements in groups 1 to 12 of the periodic table (except hydrogen) and (ii) all elements in groups 13 to 16 of the periodic table (except B, Si, Ge, As, Sb, Te, C, N, P, O, S, and Se). Metal elements can form inorganic compounds with halide ions and become cations.

[0066] In formula (A), M may include Y (i.e., yttrium). A halide solid electrolyte containing Y is Li ａ Me ｂ Y ｃ X ６ The composition may be as shown by (where a + mb + 3c = 6, c > 0, Me is at least one selected from the group consisting of metallic elements and metalloid elements other than Li and Y, and m is the valence of Me). Me may be, for example, at least one selected from the group consisting of Mg, Ca, Sr, Ba, Zn, Sc, Al, Ga, Bi, Zr, Hf, Ti, Sn, Ta, and Nb.

[0067] The solid electrolyte of a halide is given by formula (A1): Li ６－３ｄ Y ｄ X ６ It may have the composition shown in formula (A1). In formula (A1), X is one or more elements selected from the group consisting of Cl, Br, and I. d may satisfy 0 < d < 2, or d = 1. The halide solid electrolyte is given by formula (A2): Li ３－３δ Y １＋δ Cl ６ It may have the composition shown in formula (A2). In formula (A2), 0 < δ ≤ 0.15. The halogen solid electrolyte is formula (A3): Li３－３δ Y １＋δ Br ６ It may have the composition shown in formula (A3). In formula (A3), 0 < δ ≤ 0.25. The halogen solid electrolyte is formula (A4): Li ３－３δ＋ａ Y １＋δ－ａ Me ａ Cl ６－ｘ－ｙ Br ｘ I ｙ It may have the composition shown in formula (A4). In formula (A4), Me may be at least one selected from the group consisting of Mg, Ca, Sr, Ba and Zn. In formula (A4), for example, -1 < δ < 2, 0 < a < 3, 0 < (3 - 3δ + a), 0 < (1 + δ - a), 0 ≤ x ≤ 6, 0 ≤ y ≤ 6 and (x + y) ≤ 6 are satisfied. The halide solid electrolyte is given by formula (A5): Li ３－３δ Y １＋δ－ａ Me ａ Cl ６－ｘ－ｙ Br ｘ I ｙ It may have the composition shown in formula (A5). In formula (A5), Me may be at least one selected from the group consisting of Al, Sc, Ga, and Bi. In formula (A5), -1 < δ < 1, 0 < a < 2, 0 < (1 + δ - a), 0 ≤ x ≤ 6, 0 ≤ y ≤ 6, and (x + y) ≤ 6. The halide solid electrolyte is given by formula (A6): Li ３－３δ－ａ Y １＋δ－ａ Me ａ Cl ６－ｘ－ｙ Br ｘ I ｙ It may have the composition shown in formula (A6). In formula (A6), Me may be at least one selected from the group consisting of Zr, Hf, and Ti. In formula (A6), -1 < δ < 1, 0 < a < 1.5, 0 < (3 - 3δ - a), 0 < (1 + δ - a), 0 ≤ x ≤ 6, 0 ≤ y ≤ 6, and (x + y) ≤ 6. The halide solid electrolyte is given by formula (A7): Li ３－３δ－２ａ Y １＋δ－ａ Me ａ Cl ６－ｘ－ｙ Br ｘ I ｙIt may have the composition shown in formula (A7). In formula (A7), Me may be at least one selected from the group consisting of Ta and Nb. In formula (A7), -1 < δ < 1, 0 < a < 1.2, 0 < (3 - 3δ - 2a), 0 < (1 + δ - a), 0 ≤ x ≤ 6, 0 ≤ y ≤ 6, and (x + y) ≤ 6.

[0068] The ionic solid electrolyte may also be a complex hydride solid electrolyte. The complex hydride solid electrolyte may be composed of a complex ion containing Li ions and H. The complex ion containing H may, for example, have an element M containing at least one of a nonmetallic element, a metalloid element, and a metallic element, and H bonded to the element M. In addition, in the complex ion containing H, the element M as the central element and the H surrounding the element M may be bonded to each other via covalent bonds. In addition, the complex ion containing H may have (M ｍ H ｎ ) α－ It may also be represented as follows: In this case, m is any positive number, and n and α can be any positive number depending on m, the valence of element M, etc. Element M can be any nonmetallic or metallic element that can form a complex ion. For example, element M may contain at least one of B, C, and N as a nonmetallic element, or it may contain B. Also, for example, element M may contain at least one of Al, Ni, and Fe as a metallic element. In particular, when the complex ion contains B, or contains C and B, higher ionic conductivity is more easily ensured. A specific example of a complex ion containing H is (CB ９ H １０ ) － , (CB １１ H １２ ) － , (B １０ H １０ ) ２－ , (B １２ H １２ ) ２－ , (BH ４ ) － , (NH ２ ) － , (AlH ４ ) － , and combinations thereof are examples. In particular, (CB９ H １０ ) － , (CB １１ H １２ ) － Alternatively, using a combination of these can easily ensure higher ionic conductivity. In other words, the complex hydride solid electrolyte may contain Li, C, B, and H.

[0069] 5.2.3.2 Liquid Electrolyte The liquid electrolyte (electrolyte) is a liquid containing lithium ions as carrier ions. The electrolyte may be the electrolyte according to the embodiment described above, or it may be another electrolyte (other electrolyte), or a combination thereof. The other electrolyte may be an aqueous electrolyte or a non-aqueous electrolyte. The composition of the other electrolyte may be the same as that known for the composition of battery electrolytes. The other electrolyte may be a solution of lithium salt in water or a non-aqueous solvent. Examples of non-aqueous solvents include the various carbonate-based solvents described above. Examples of lithium salts include the lithium amide salt and LiPF mentioned above. ６ These are some examples.

[0070] 5.2.4 Conductive Additives Examples of conductive additives that may be included in the positive electrode active material layer 20 include carbon materials such as vapor-processed carbon fiber (VGCF), acetylene black (AB), Ketjenblack (KB), carbon nanotubes (CNT), and carbon nanofibers (CNF); and metallic materials such as nickel, titanium, aluminum, and stainless steel. The conductive additive may be in the form of parts or fibers, and its size is not particularly limited. One type of conductive additive may be used alone, or two or more types may be used in combination.

[0071] 5.2.5 Binder Examples of binders that may be included in the positive electrode active material layer 20 include butadiene rubber (BR) binders, butylene rubber (IIR) binders, acrylate butadiene rubber (ABR) binders, styrene butadiene rubber (SBR) binders, polyvinylidene fluoride (PVdF) binders, polytetrafluoroethylene (PTFE) binders, polyimide (PI) binders, and the like. A single binder may be used alone, or two or more binders may be used in combination.

[0072] 5.2.6 In addition to the above-mentioned components, the positive electrode active material layer 20 may also contain various additives. For example, dispersants and lubricants. The positive electrode active material layer 20 can be manufactured by applying known methods. For example, the positive electrode active material layer 20 can be easily formed by molding a positive electrode mixture containing the above-mentioned components in a dry or wet manner. The positive electrode active material layer 20 may be molded together with the positive electrode current collector 10, or it may be molded separately from the positive electrode current collector 10.

[0073] 5.3 Electrolyte layer The battery 100 includes an electrolyte layer 30. The electrolyte layer 30 is disposed between the positive electrode active material layer 20 and the negative electrode active material layer 40. The electrolyte layer 30 contains at least an electrolyte. The electrolyte layer 30 may contain at least one of a solid electrolyte and an electrolyte solution, and may further optionally contain a binder, etc. If the electrolyte layer 30 contains the electrolyte solution and / or the lithium ion conductive material according to the above embodiment, the electrolyte layer 30 may further contain other electrolytes, binders, and various additives in addition to the electrolyte solution and lithium ion conductive material. The content of electrolyte and binder, etc. in the electrolyte layer 30 is not particularly limited. Alternatively, the electrolyte layer 30 may have a separator, etc., to hold the electrolyte solution and prevent contact between the positive electrode active material layer 20 and the negative electrode active material layer 40. The thickness of the electrolyte layer 30 is not particularly limited and may be, for example, 0.1 μm or more or 1 μm or more, or 2 mm or less or 1 mm or less.

[0074] The electrolyte layer 30 may consist of one layer or multiple layers. For example, the electrolyte layer 30 may comprise a first layer located on the positive electrode active material layer 20 side and a second layer located on the negative electrode active material layer 40 side, wherein the first layer contains a first electrolyte and the second layer contains a second electrolyte. The first electrolyte and the second electrolyte may be of different types. The first electrolyte and the second electrolyte may each be at least one selected from the oxide solid electrolyte, sulfide solid electrolyte and ionic solid electrolyte described above. For example, the first layer may contain an ionic solid electrolyte, and the second layer may contain at least one of the ionic solid electrolyte and sulfide solid electrolyte.

[0075] The electrolyte contained in the electrolyte layer 30 may be appropriately selected from the electrolyte solution according to the above embodiment, the lithium ion conductive material according to the above embodiment, and the electrolytes exemplified as electrolytes that can be contained in the positive electrode active material layer (other solid electrolytes, other liquid electrolytes). Similarly, the binder that can be contained in the electrolyte layer 30 may be appropriately selected from the binders exemplified as binders that can be contained in the positive electrode active material layer. The electrolyte and binder may be used individually or in combination of two or more types. The separator may be any separator commonly used in batteries, such as those made of polyethylene (PE), polypropylene (PP), polyester, and polyamide resins. The separator may have a single-layer structure or a multi-layer structure. Examples of multi-layer separators include a PE / PP two-layer separator, or a PP / PE / PP or PE / PP / PE three-layer separator. The separator may be made of a nonwoven fabric such as cellulose nonwoven fabric, resin nonwoven fabric, or glass fiber nonwoven fabric.

[0076] 5.4 The negative electrode active material layer battery 100 comprises a negative electrode active material layer 40. The negative electrode active material layer 40 contains at least a negative electrode active material. The negative electrode active material layer 40 may also optionally contain an electrolyte, a conductive additive, a binder, and various additives. If the negative electrode active material layer 40 contains the electrolyte and / or lithium ion conductive material according to the above embodiment, the negative electrode active material layer 40 may further optionally contain other electrolytes, conductive additives, binders, and various additives in addition to the negative electrode active material and the electrolyte and / or lithium ion conductive material. The content of each component in the negative electrode active material layer 40 may be appropriately determined according to the desired battery performance. For example, with the total solid content of the negative electrode active material layer 40 being 100% by mass, the negative electrode active material content may be 40% by mass or more, 50% by mass or more, 60% by mass or more, or 70% by mass or more, or 100% by mass or less, less than 100% by mass, 95% by mass or less, or 90% by mass or less. Alternatively, with the entire negative electrode active material layer 40 being 100% by volume, the negative electrode active material and optionally an electrolyte, conductive additive, and binder may together be 85% by volume or more, 90% by volume or more, or 95% by volume or more, with the remainder being void or other components. The shape of the negative electrode active material layer 40 is not particularly limited, and for example, it may be a sheet with a substantially flat surface. The thickness of the negative electrode active material layer 40 is not particularly limited, and for example, it may be 0.1 μm or more, 1 μm or more, 10 μm or more, or 30 μm or more, or 2 mm or less, 1 mm or less, 500 μm or less, or 100 μm or less.

[0077] 5.4.1 Negative Electrode Active Material Any known negative electrode active material for batteries can be used as the negative electrode active material. Among the known active materials, various materials can be used in which the potential for intercalation and release of lithium ions (charge / discharge potential) is lower than that of the positive electrode active material. For example, silicon-based active materials such as Si, Si alloys, and silicon oxide; carbon-based active materials such as graphite and hard carbon; various oxide-based active materials such as lithium titanate; metallic lithium and lithium alloys can be used. In particular, the performance of the battery 100 tends to improve when the negative electrode active material layer 40 contains Si as the negative electrode active material. The negative electrode active material may be used alone or in combination of two or more types.

[0078] The shape of the negative electrode active material can be any shape that is common for negative electrode active materials in batteries. For example, the negative electrode active material may be particulate. The negative electrode active material particles may be primary particles or secondary particles formed by the aggregation of multiple primary particles. The average particle diameter (D50) of the negative electrode active material particles may be, for example, 1 nm or more, 5 nm or more, or 10 nm or more, or 500 μm or less, 100 μm or less, 50 μm or less, or 30 μm or less. Alternatively, the negative electrode active material may be in the form of a sheet (foil or film) such as lithium foil. That is, the negative electrode active material layer 40 may consist of a sheet of negative electrode active material.

[0079] 5.4.2 Other electrolytes that may be included in the negative electrode active material layer 40 may be appropriately selected from, for example, the electrolyte according to the above embodiment, the lithium ion conductive material according to the above embodiment, and the electrolytes exemplified as electrolytes that may be included in the positive electrode active material layer (other solid electrolytes, other liquid electrolytes). Conductive additives that may be included in the negative electrode active material layer 40 may be appropriately selected from, for example, those exemplified as conductive additives that may be included in the positive electrode active material layer. Binders that may be included in the negative electrode active material layer 40 may be appropriately selected from, for example, those exemplified as binders that may be included in the positive electrode active material layer. Electrolytes, conductive additives, and binders may each be used individually or in combination of two or more types. The negative electrode active material layer 40 can be manufactured by applying known methods. For example, the negative electrode active material layer 40 can be easily formed by dry or wet molding of a negative electrode mixture containing the above-mentioned components. The negative electrode active material layer 40 may be molded together with the negative electrode current collector 50, or it may be molded separately from the negative electrode current collector 50.

[0080] 5.5 Negative electrode current collector The battery 100 may include a negative electrode current collector 50 that is in contact with the negative electrode active material layer 40. Any of the negative electrode current collectors commonly used for batteries can be used as the negative electrode current collector 50. The negative electrode current collector 50 may be in the form of a sheet (foil, plate), mesh, perforated metal, or foam. The negative electrode current collector 50 may be a metal foil or metal mesh, or a carbon sheet. The negative electrode current collector 50 may be made of a resin composition containing a conductive material and a resin. The negative electrode current collector 50 may consist of multiple foils or sheets. Examples of metals that make up the negative electrode current collector 50 include at least one selected from Cu, Ni, Cr, Au, Pt, Ag, Al, Fe, Ti, Zn, Co, V, Mg, Pb, Ge, In, Sn, Zr, and stainless steel. In particular, from the viewpoint of ensuring resistance to reduction and being less prone to alloying with lithium, the negative electrode current collector 50 may contain at least one metal selected from Cu, Ni, and stainless steel. The negative electrode current collector 50 may have some kind of coating layer on its surface for the purpose of adjusting resistance, etc. For example, the negative electrode current collector 50 may have a carbon coating layer. The negative electrode current collector 50 may be aluminum foil having a carbon coating layer. Alternatively, the negative electrode current collector 50 may be a metal foil or a substrate on which the above metals are plated or deposited. Furthermore, if the negative electrode current collector 50 consists of multiple metal foils, there may be some kind of layer between the multiple metal foils. The thickness of the negative electrode current collector 50 is not particularly limited. For example, it may be 0.1 μm or more or 1 μm or more, or 1 mm or less or 100 μm or less.

[0081] 5.6 Other In addition to the above configuration, the battery 100 may have other configurations common to batteries. For example, tabs and terminals. The battery 100 may have each of the above configurations housed inside an outer casing. Any known battery casing can be used. Furthermore, multiple batteries 100 may be electrically connected and stacked as desired to form a battery pack. In this case, the battery pack may be housed inside a known battery case. The battery 100 may also have other obvious configurations such as necessary terminals. Examples of the shape of the battery 100 include coin type, laminate type, cylindrical type, and prismatic type. The battery 100 may be a rechargeable battery. The battery 100 may be a lithium-ion battery.

[0082] The battery 100 can be manufactured by applying known methods. For example, it can be manufactured as follows. However, the manufacturing method of the battery 100 is not limited to the following method, and each layer may be formed by, for example, dry molding. (1) A positive electrode slurry is obtained by dispersing the positive electrode active material constituting the positive electrode active material layer in a solvent. The solvent used in this case is not particularly limited, and water or various organic solvents can be used. The positive electrode slurry is coated onto the surface of the positive electrode current collector using a doctor blade or the like, and then dried to form a positive electrode active material layer on the surface of the positive electrode current collector, which serves as the positive electrode. (2) A negative electrode slurry is obtained by dispersing the negative electrode active material constituting the negative electrode active material layer in a solvent. The solvent used in this case is not particularly limited, and water or various organic solvents can be used. The negative electrode slurry is coated onto the surface of the negative electrode current collector using a doctor blade or the like, and then dried to form a negative electrode active material layer on the surface of the negative electrode current collector, which serves as the negative electrode. (3) The layers are stacked so that the electrolyte layer (solid electrolyte layer or separator) is sandwiched between the negative electrode and the positive electrode, to obtain a laminate having a negative electrode current collector, a negative electrode active material layer, an electrolyte layer, a positive electrode active material layer, and a positive electrode current collector in this order. Other components such as terminals are attached to the laminate as needed. (4) The laminate is housed in a battery case, and in the case of an electrolyte battery, the battery case is filled with electrolyte, the laminate is immersed in the electrolyte, and the laminate is sealed inside the battery case to make a secondary battery. Note that in the case of a battery containing an electrolyte, the negative electrode active material layer, separator and positive electrode active material layer may be made to contain the electrolyte at the stage of (3) above.

[0083] 6. Composite Solid Electrolytes and Composite Active Materials As described above, the lithium-ion conductive material according to this embodiment may be integrated with a solid electrolyte or integrated with an active material. For example, by preparing a solution of the electrolyte, polymer and diluent according to this embodiment as described above, coating the surface of the solid electrolyte or active material with the solution, and then removing the diluent, at least a portion of the surface of the solid electrolyte or active material can be covered with the lithium-ion conductive material according to this embodiment, thereby enabling the production of a composite solid electrolyte or a composite active material. More specifically, a composite solid electrolyte according to one embodiment includes a lithium-ion conductive material and a solid electrolyte, wherein the lithium-ion conductive material is the lithium-ion conductive material according to the above embodiment (for example, the lithium-ion conductive material includes a composite of an electrolyte and a polymer, and the electrolyte is the electrolyte according to the above embodiment), the solid electrolyte is at least one selected from the group consisting of oxide solid electrolytes, sulfide solid electrolytes and ionic solid electrolytes, and at least a portion of the surface of the solid electrolyte is covered with the lithium-ion conductive material. Alternatively, a composite active material according to one embodiment comprises a lithium ion conductive material and an active material, wherein the lithium ion conductive material is the lithium ion conductive material according to the above embodiment (for example, the lithium ion conductive material comprises a composite of an electrolyte and a polymer, and the electrolyte is the electrolyte according to the above embodiment), and at least a portion of the surface of the active material is coated with the lithium ion conductive material. The solid electrolyte and the active material may be, for example, particulate, as described above. The active material may be a positive electrode active material or a negative electrode active material.

[0084] 7. Vehicle As described above, the battery according to this embodiment comprises an electrolyte and / or a lithium-ion conductive material having high lithium-ion conductivity. Furthermore, when the battery comprises the above-described lithium-ion conductive material, excellent electrochemical stability (e.g., oxidation stability) is exhibited, and even if the battery is repeatedly charged and discharged, decomposition of the lithium-ion conductive material and corrosion of the current collector are unlikely to occur. Such a battery can be suitably used in, for example, at least one type of vehicle selected from hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and electric electric vehicles (BEVs). That is, the technology of this disclosure also has an aspect as a vehicle having a battery, wherein the battery includes one or both of the electrolyte and the lithium-ion conductive material according to the above-described embodiment. Details of the battery configuration are as described above.

[0085] The technology of this disclosure will be described in more detail below with reference to examples, but the technology of this disclosure is not limited to the following examples. All of the following experiments were conducted in a glove box or a similar non-air-exposure environment under an Ar atmosphere with a dew point of -80°C or lower and an oxygen concentration of less than 3 ppm.

[0086] 1. Preparation and Evaluation of Electrolyte (Part 1) The electrolyte was prepared as follows, and its lithium ion conductivity was evaluated.

[0087] 1.1 Preparation of Electrolyte 1.1.1 Examples 1-1 to 1-7 Propylene carbonate (PC, manufactured by Kishida Chemical Co., Ltd.) as the main solvent, lithium bisfluorosulfonylamide (LiFSA, manufactured by Kishida Chemical Co., Ltd.) as the lithium salt, and diethylene glycol dimethyl ether (G2, manufactured by Kishida Chemical Co., Ltd.) as the secondary solvent were weighed in a molar ratio of main solvent:lithium salt:secondary solvent = 3.00:1.00:X, and the mixture was stirred and mixed to obtain an electrolyte for evaluation. X was set to 0.20, 1.00, 1.50, 2.00, 2.50, 3.00, or 6.00.

[0088] 1.1.2 Examples 2-1 to 2-11 Propylene carbonate (PC, manufactured by Kishida Chemical Co., Ltd.) as the main solvent, lithium bisfluorosulfonylamide (LiFSA, manufactured by Kishida Chemical Co., Ltd.) as the lithium salt, and triethylene glycol dimethyl ether (G3, manufactured by Kanto Chemical Co., Ltd.) as the secondary solvent were weighed in a molar ratio of main solvent:lithium salt:secondary solvent = 3.00:1.00:X, and the mixture was stirred and mixed to obtain an electrolyte for evaluation. X was set to 0.10, 0.20, 0.50, 1.00, 1.10, 1.25, 1.40, 1.50, 2.00, 2.50, or 3.00.

[0089] 1.1.3 Examples 3-1 to 3-4 Propylene carbonate (PC, manufactured by Kishida Chemical Co., Ltd.) as the main solvent, lithium bisfluorosulfonylamide (LiFSA, manufactured by Kishida Chemical Co., Ltd.) as the lithium salt, and tetraethylene glycol dimethyl ether (G4, manufactured by Kishida Chemical Co., Ltd.) as the secondary solvent were weighed in a molar ratio of main solvent:lithium salt:secondary solvent = 3.00:1.00:X, and the mixture was stirred and mixed to obtain an electrolyte for evaluation. X was set to 1.00, 1.50, 2.00, or 2.50.

[0090] 1.1.4 Examples 4-1 and 4-2 Propylene carbonate (PC, manufactured by Kishida Chemical Co., Ltd.) as the main solvent, lithium bisfluorosulfonylamide (LiFSA, manufactured by Kishida Chemical Co., Ltd.) as the lithium salt, and dipropylene glycol dimethyl ether (DPGDME, manufactured by Aldrich Corporation) as the secondary solvent were weighed in a molar ratio of main solvent:lithium salt:secondary solvent = 3.00:1.00:X, and the mixture was stirred and mixed to obtain an electrolyte for evaluation. X was set to 0.20 or 3.00.

[0091] 1.1.5 Examples 5-1 and 5-2 Propylene carbonate (PC, manufactured by Kishida Chemical Co., Ltd.) as the main solvent, lithium bisfluorosulfonylamide (LiFSA, manufactured by Kishida Chemical Co., Ltd.) as the lithium salt, and 1-methoxy-3-(3-methoxypropoxy)propane (1M33MPP, manufactured by ChemScene Inc.) as the secondary solvent were weighed in a molar ratio of main solvent:lithium salt:secondary solvent = 3.00:1.00:X, and the mixture was stirred and mixed to obtain an electrolyte for evaluation. X was set to 1.00 or 3.00.

[0092] 1.1.6 Comparative Examples 1-1 to 1-4 In Comparative Examples 1-1 to 1-4, propylene carbonate (PC, manufactured by Kishida Chemical Co., Ltd.) as the solvent and lithium bisfluorosulfonylamide (LiFSA, manufactured by Kishida Chemical Co., Ltd.) as the lithium salt were weighed in a molar ratio of solvent:lithium salt = 3.00 + X : 1.00, and the electrolyte for evaluation was obtained by stirring and mixing. In other words, in Comparative Examples 1-1 to 1-4, propylene carbonate was used as both the main solvent and the secondary solvent, and the main solvent:lithium salt:secondary solvent was weighed in a ratio of main solvent:lithium salt:secondary solvent = 3.00:1.00:X, and the electrolyte for evaluation was obtained by stirring and mixing. X was set to 0, 1.00, 3.00, or 6.00. Furthermore, for example, Comparative Examples 1-3 can be described as being weighed, stirred, and mixed so that the ratio of main solvent:lithium salt:secondary solvent is 5.00:1.00:1.00.

[0093] 1.1.7 Comparative Examples 2-1 to 2-3 Propylene carbonate (PC, manufactured by Kishida Chemical Co., Ltd.) as the main solvent, lithium bisfluorosulfonylamide (LiFSA, manufactured by Kishida Chemical Co., Ltd.) as the lithium salt, and diethyl carbonate (DEC, manufactured by Kishida Chemical Co., Ltd.) as the secondary solvent were weighed in a molar ratio of main solvent:lithium salt:secondary solvent = 3.00:1.00:X, and the mixture was stirred and mixed to obtain an electrolyte for evaluation. X was set to 1.00, 3.00, or 6.00.

[0094] 1.2 Evaluation Method of Electrolyte 1.2.1 Ionic Conductivity and Lithium Ion Transport Number (tLi ＋Evaluation of each of the above electrolytes: Using Li metal electrodes and a fixed distance between electrodes, the ionic conductivity was determined at 25°C using the complex impedance method in a two-electrode symmetric cell. The lithium ion transport fraction was then determined using the Bruce method (Bruce et al. Solid State Ionics 28-30, 1987, 918-922), which combines DC polarization and impedance methods.

[0095] 1.2.2 Calculation of Lithium Ion Conductivity The lithium ion conductivity (σLi+) of the electrolyte was determined by multiplying the lithium ion transport fraction and ionic conductivity obtained by the electrochemical method described above.

[0096] 1.3 Evaluation Results The lithium ion conductivity of each electrolyte is shown in Table 1 and Figure 2 below.

[0097] The results shown in Table 1 and Figure 2 indicate that electrolytes containing ether compounds with repeating ether units along with cyclic carbonates and lithium amide salts exhibit high lithium ion conductivity. Furthermore, high lithium ion conductivity is ensured regardless of whether the molar ratio of the ether compound in the electrolyte is low or high. It is believed that the repeating ether units form a regular structure containing ether groups in the electrolyte, thereby exhibiting a function of selectively transporting lithium ions, resulting in increased lithium ion conductivity of the electrolyte.

[0098] 2. Preparation and Evaluation of Electrolyte (Part 2) In the above example, the evaluation results of an electrolyte with a molar ratio of lithium salt to main solvent (lithium salt / main solvent) of 0.33 were shown. In the following example, the evaluation results of an electrolyte with a molar ratio of lithium salt to main solvent (lithium salt / main solvent) of 0.25 or 0.20 are shown.

[0099] 2.1 Preparation of Electrolyte 2.1.1 Example 6-1 Propylene carbonate (PC, manufactured by Kishida Chemical Co., Ltd.) as the main solvent, lithium bisfluorosulfonylamide (LiFSA, manufactured by Kishida Chemical Co., Ltd.) as the lithium salt, and triethylene glycol dimethyl ether (G3, manufactured by Kanto Chemical Co., Ltd.) as the secondary solvent were weighed in a molar ratio of main solvent:lithium salt:secondary solvent = 4.00:1.00:1.00, and the mixture was stirred and mixed to obtain an electrolyte for evaluation.

[0100] 2.1.2 Example 6-2 Propylene carbonate (PC, manufactured by Kishida Chemical Co., Ltd.) as the main solvent, lithium bisfluorosulfonylamide (LiFSA, manufactured by Kishida Chemical Co., Ltd.) as the lithium salt, and tetraethylene glycol dimethyl ether (G4, manufactured by Kishida Chemical Co., Ltd.) as the secondary solvent were weighed in a molar ratio of main solvent:lithium salt:secondary solvent = 4.00:1.00:1.00, and the mixture was stirred and mixed to obtain an electrolyte for evaluation.

[0101] 2.1.3 Example 6-3 Propylene carbonate (PC, manufactured by Kishida Chemical Co., Ltd.) as the main solvent, lithium bisfluorosulfonylamide (LiFSA, manufactured by Kishida Chemical Co., Ltd.) as the lithium salt, and triethylene glycol dimethyl ether (G3, manufactured by Kanto Chemical Co., Ltd.) as the secondary solvent were weighed in a molar ratio of main solvent:lithium salt:secondary solvent = 4.00:1.00:3.00, and the mixture was stirred and mixed to obtain an electrolyte for evaluation.

[0102] 2.1.4 Comparative Example 3-1 Propylene carbonate (PC, manufactured by Kishida Chemical Co., Ltd.) as the main solvent and secondary solvent, and lithium bisfluorosulfonylamide (LiFSA, manufactured by Kishida Chemical Co., Ltd.) as the lithium salt were weighed in a molar ratio of main solvent:lithium salt:secondary solvent = 4.00:1.00:1.00, and the mixture was stirred and mixed to obtain an electrolyte for evaluation.

[0103] 2.1.5 Example 7-1 Propylene carbonate (PC, manufactured by Kishida Chemical Co., Ltd.) as the main solvent, lithium bisfluorosulfonylamide (LiFSA, manufactured by Kishida Chemical Co., Ltd.) as the lithium salt, and triethylene glycol dimethyl ether (G3, manufactured by Kanto Chemical Co., Ltd.) as the secondary solvent were weighed in a molar ratio of main solvent:lithium salt:secondary solvent = 5.00:1.00:1.00, and the mixture was stirred and mixed to obtain an electrolyte for evaluation.

[0104] 2.1.6 Example 7-2 Propylene carbonate (PC, manufactured by Kishida Chemical Co., Ltd.) as the main solvent, lithium bisfluorosulfonylamide (LiFSA, manufactured by Kishida Chemical Co., Ltd.) as the lithium salt, and tetraethylene glycol dimethyl ether (G4, manufactured by Kishida Chemical Co., Ltd.) as the secondary solvent were weighed in a molar ratio of main solvent:lithium salt:secondary solvent = 5.00:1.00:1.00, and the mixture was stirred and mixed to obtain an electrolyte for evaluation.

[0105] 2.1.7 Example 7-3 Propylene carbonate (PC, manufactured by Kishida Chemical Co., Ltd.) as the main solvent, lithium bisfluorosulfonylamide (LiFSA, manufactured by Kishida Chemical Co., Ltd.) as the lithium salt, and triethylene glycol dimethyl ether (G3, manufactured by Kanto Chemical Co., Ltd.) as the secondary solvent were weighed in a molar ratio of main solvent:lithium salt:secondary solvent = 5.00:1.00:3.00, and the mixture was stirred and mixed to obtain an electrolyte for evaluation.

[0106] 2.2 Evaluation Method of Electrolytes For each electrolyte, the lithium ion conductivity (σLi+) was determined using the method described above.

[0107] 2.3 Evaluation Results The lithium ion conductivity of each electrolyte is shown in Tables 2 and 3 below.

[0108] The results shown in Tables 2 and 3 indicate that when an ether compound comprising repeated ether units is included in the electrolyte along with the cyclic carbonate and lithium amide salt, a higher lithium ion conductivity is achieved compared to when the ether compound is not included. Furthermore, this effect is observed regardless of the molar ratio of the cyclic carbonate and lithium amide salt in the electrolyte.

[0109] 3. Fabrication and Evaluation of Lithium-Ion Conducting Materials (Composites of Electrolyte and Polymer) Lithium-ion conducting materials (composites of electrolyte and polymer) were fabricated as follows, and their lithium-ion conductivity was evaluated.

[0110] 3.1 Preparation of Lithium Ion Conducting Material 3.1.1 Example A The electrolyte according to Example 2-4 (auxiliary solvent: G3, X = 1.00), a copolymer of polyvinylidene fluoride and hexafluoropropylene (manufactured by Kureha Corporation), and dimethyl carbonate (DMC, manufactured by Kishida Chemical Co., Ltd.) as a diluent were mixed and heated and stirred to obtain a homogeneous solution. Here, the amount of copolymer was set to 20% by mass of the total material after removal of the diluent. After casting the obtained solution at 60°C, the diluent was removed by drying to obtain a lithium ion conducting material which is a composite of the electrolyte and copolymer.

[0111] 3.1.2 Example B A lithium ion conductive material was obtained in the same manner as in Example A, except that the electrolyte according to Example 2-11 (auxiliary solvent: G3, X = 3.00) was used.

[0112] 3.1.3 Example C A lithium ion conductive material was obtained in the same manner as in Example A, except that the electrolyte according to Example 3-1 (auxiliary solvent: G4, X = 1.00) was used.

[0113] 3.1.4 Comparative Example A A lithium ion conductive material was obtained in the same manner as in Example A, except that the electrolyte according to Comparative Example 1-1 (auxiliary solvent: none, X=0) was used.

[0114] 3.1.5 Comparative Example B A lithium ion conductive material was obtained in the same manner as in Example A, except that the electrolyte according to Comparative Example 1-2 (auxiliary solvent: PC, X = 1.00) was used.

[0115] 3.1.6 Comparative Example B A lithium ion conductive material was obtained in the same manner as in Example A, except that the electrolyte according to Comparative Example 1-3 (auxiliary solvent: PC, X = 3.00) was used.

[0116] 3.2 Evaluation Methods for Lithium Ion Conducting Materials 3.2.1 Ionic Conductivity and Lithium Ion Transport Number (tLi ＋ Evaluation of each of the above lithium ion conductive materials: Using Li metal as the electrodes and a fixed distance between electrodes, the ionic conductivity was determined by the complex impedance method at 25°C in a two-electrode symmetric cell, and the lithium ion transport fraction was determined by the Bruce method (Bruce et al. Solid State Ionics 28-30, 1987, 918-922), which combines DC polarization and impedance methods.

[0117] 3.2.2 Calculation of Lithium Ion Conductivity The lithium ion conductivity (σLi+) of the lithium ion conductive material was determined by multiplying the lithium ion transport fraction and ionic conductivity obtained by the electrochemical method described above.

[0118] 3.3 Evaluation Results Figure 3 shows the lithium ion conductivity of each lithium ion conducting material. From the results shown in Figure 3, it can be seen that by compounding cyclic carbonates and lithium amide salts with an electrolyte polymer containing an ether compound having repeating ether units, a lithium ion conducting material (polymer electrolyte) with high lithium ion conductivity can be obtained. As described above, the repeating ether units form a regular structure containing ether groups in the lithium ion conducting material, which is thought to exhibit a function of selectively transporting lithium ions, and as a result, the lithium ion conductivity of the lithium ion conducting material is increased.

[0119] 4. Evaluation of Electrochemical Stability The electrochemical stability of each of the following was evaluated by performing cyclic voltammetry (CV) tests: cyclic voltammetry (CV) tests. Specifically, in a two-electrode cell using Al as the working electrode and metallic Li as the counter electrode / reference electrode, the evaluation sample (electrolyte or lithium-ion conductive material) was placed between the working electrode and the counter electrode, and the CV test was performed at 25°C with a sweep rate of 1 mV / s. The results are shown in Figures 4-6.

[0120] As shown in Figure 4, the electrolyte containing an ether compound with repeating ether units (Examples 2-4 and 3-1) exhibits reduced oxidation stability compared to the electrolyte without the ether compound (Comparative Examples 1-1 and 1-2). In cells using the electrolyte containing the ether compound, it is believed that decomposition of the ether compound and corrosion of the working electrode (Al) occur during CV testing.

[0121] In contrast, as shown in Figure 5, lithium-ion conductive materials, which are composites of electrolyte and polymer, exhibit excellent oxidation stability. It is thought that by compounding the electrolyte with the polymer, the fluidity of the electrolyte is reduced, suppressing the diffusion of reaction substrates and reaction products, and thus suppressing side reactions.

[0122] Furthermore, as shown in Figure 6, when the electrolyte is compounded with a polymer, it can be seen that high oxidation stability is ensured even if the amount of ether compound contained in the electrolyte is increased. Also, as shown in Figure 6, it can be seen that oxidation stability is improved when the electrolyte compounded with the polymer contains an ether compound that has repeated ether units compared to when it does not contain the ether compound.

[0123] 5. Supplementary Information In the above embodiment, we confirmed how the lithium ion conductivity of the electrolyte changes when the type and molar ratio of the ether compound containing repeated ether units are changed, while keeping the molar ratio of the cyclic carbonate to the lithium amide salt contained in the electrolyte fixed. However, the molar ratio of the cyclic carbonate to the lithium amide salt contained in the electrolyte is not limited to the specific ratio described above. The molar ratio of the cyclic carbonate to the lithium amide salt can be appropriately determined according to the target performance of the electrolyte.

[0124] In the above examples, specific compounds were used as the cyclic carbonate or lithium amide salt contained in the electrolyte. However, the types of cyclic carbonates and lithium amide salts are not limited to the specific types mentioned above. The types of cyclic carbonates and lithium amide salts should be determined appropriately according to the target performance of the electrolyte.

[0125] In the above embodiment, a specific copolymer was used as the polymer constituting the lithium-ion conductive material (polymer electrolyte). However, the type of polymer constituting the lithium-ion conductive material is not limited to the specific type described above. Any polymer that can be compounded with the electrolyte may be used.

[0126] 6. Summary From the above examples, it can be said that the following electrolytes and lithium-ion conductive materials have high lithium-ion conductivity. Furthermore, the following lithium-ion conductive materials can be said to have excellent electrochemical stability. (1) An electrolyte comprising a cyclic carbonate, a lithium amide salt, and an ether compound having repeating ether units. (2) A lithium-ion conductive material comprising a cyclic carbonate, a lithium amide salt, an ether compound having repeating ether units, and a polymer.

[0127] 10 positive electrode current collector 20 positive electrode active material layer 30 electrolyte layer 40 negative electrode active material layer 50 negative electrode current collector 100 battery

Claims

1. An electrolyte comprising a cyclic carbonate, a lithium amide salt, and an ether compound having repeating ether units.

2. The electrolyte according to claim 1, wherein the ether compound is of the following formula (1): R １ - ( OR ３ ) ｎ -O-R ２ (1) R １ : Hydrocarbon group with 1 to 5 carbon atoms R ２ : Hydrocarbon group with 1 to 5 carbon atoms R ３ : A hydrocarbon group having 1 to 5 carbon atoms; n: One or more compounds represented by an integer between 2 and 7, which constitute the electrolyte.

3. The electrolytic solution according to claim 2, wherein R １ is an alkyl group having 1 to 3 carbon atoms, and R ２ is an alkyl group having 1 to 3 carbon atoms, and R ３ is an alkylene group having 2 or 3 carbon atoms, and n is an integer of 2 to 4. electrolytic solution.

4. The electrolyte according to claim 1, wherein the ether compound is one or more of diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, and 1-methoxy-3-(3-methoxypropoxy)propane.

5. An electrolyte according to any one of claims 1 to 4, wherein the molar ratio of the ether compound to the cyclic carbonate (ether compound / cyclic carbonate) is greater than 0 and less than or equal to 1.

00.

6. An electrolyte according to any one of claims 1 to 5, wherein the cyclic carbonate is one or both of propylene carbonate and ethylene carbonate.

7. An electrolyte according to any one of claims 1 to 6, wherein the lithium amide salt is one or both of lithium bisfluorosulfonylamide and lithium bistrifluoromethanesulfonylamide.

8. A lithium-ion conductive material comprising a cyclic carbonate, a lithium amide salt, an ether compound having repeating ether units, and a polymer.

9. The lithium-ion conductive material according to claim 8, wherein the ether compound is of the following formula (1): R １ - ( OR ３ ) ｎ -O-R ２ (1) R １ : Hydrocarbon group with 1 to 5 carbon atoms R ２ : Hydrocarbon group with 1 to 5 carbon atoms R ３ A lithium ion conductive material in which : a hydrocarbon group having 1 to 5 carbon atoms, and n: one or more compounds represented by an integer between 2 and 7.

10. A lithium-ion conductive material according to claim 9, wherein the R １ However, the R is an alkyl group having 1 to 3 carbon atoms. ２ However, the R is an alkyl group having 1 to 3 carbon atoms. ３ A lithium ion conductive material wherein the atom is an alkylene group having 2 or 3 carbon atoms, and n is an integer between 2 and 4.

11. A lithium-ion conductive material according to claim 8, wherein the ether compound is one or both of triethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether.

12. A lithium-ion conductive material according to any one of claims 8 to 11, wherein the molar ratio of the ether compound to the cyclic carbonate (ether compound / cyclic carbonate) is greater than 0 and 1.00 or less.

13. A lithium-ion conductive material according to any one of claims 8 to 12, wherein the cyclic carbonate is one or both of propylene carbonate and ethylene carbonate.

14. A lithium ion conductive material according to any one of claims 8 to 13, wherein the lithium amide salt is one or both of lithium bisfluorosulfonylamide and lithium bistrifluoromethanesulfonylamide.

15. A lithium ion conductive material according to any one of claims 8 to 14, comprising a composite of an electrolyte and the polymer, wherein the electrolyte comprises the cyclic carbonate, the lithium amide salt, and the ether compound.

16. A battery comprising one or both of the electrolyte described in any one of claims 1 to 7 and the lithium-ion conductive material described in any one of claims 8 to 15.

17. A method for manufacturing a lithium-ion conductive material, comprising compounding an electrolyte with a polymer, wherein the electrolyte is the electrolyte described in any one of claims 1 to 7.

18. A method for producing a lithium-ion conductive material according to claim 17, comprising: mixing the electrolyte, the polymer, and a diluent to obtain a solution; and removing the diluent from the solution to composite the electrolyte and the polymer.

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