Nonaqueous electrolyte solution and nonaqueous electrolyte battery

Abstract

A nonaqueous electrolyte solution containing (I) a compound represented by general formula (1) set forth in the description, (II) a solute, (III) a nonaqueous organic solvent, and hydrogen fluoride, wherein the concentration of hydrogen fluoride with respect to the total amount of the nonaqueous electrolyte solution is 0.1-180 mass ppm; and a nonaqueous electrolyte battery including said nonaqueous electrolyte solution.

Description

Non-aqueous electrolyte and non-aqueous electrolyte battery

[0001] The present disclosure relates to a non-aqueous electrolyte and a non-aqueous electrolyte battery.

[0002] In recent years, there has been a rapid increase in demand for high-capacity, high-power, and high-energy-density batteries that can be installed as auxiliary power sources for electric vehicles, hybrid vehicles, and fuel cell vehicles, as well as for energy storage systems for small, high-energy-density applications such as information-related devices and communication devices, i.e., personal computers, video cameras, digital cameras, mobile phones, and smartphones. There is also a growing demand for batteries that can be used for long periods of time in energy storage systems for large, power applications such as power storage. Non-aqueous electrolyte batteries, such as lithium secondary batteries, have been actively developed as candidates for these various energy storage systems. Non-aqueous electrolyte batteries typically include a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte.

[0003] Patent Document 1 proposes improving the residual characteristics and suppressing resistance increase during high-temperature storage by using hydrofluoric acid as an additive to diglycolic anhydride in an electrolyte. Patent Document 2 proposes improving cycle characteristics by using an acid anhydride having a specific ring structure and a carbonate containing a fluorine atom in an electrolyte. Patent Document 3 proposes improving cycle characteristics and low-temperature characteristics by using a silicon compound in an electrolyte. Patent Document 4 proposes improving storage characteristics by using a non-aqueous electrolyte containing lithium bisfluorosulfonylimide as a solute. Patent Document 5 proposes suppressing self-discharge and improving storage characteristics after charging by using lithium monofluorophosphate or lithium difluorophosphate in an electrolyte. Patent Document 6 proposes maintaining high input / output and impedance characteristics even after durability testing by using a fluorosulfonate in a non-aqueous electrolyte. Patent Document 7 proposes suppressing decomposition on a carbon anode with increasing charge / discharge cycles by using a cyclic sulfate in a non-aqueous electrolyte. Patent Document 8 proposes that the use of a cyclic sultone (unsaturated sultone) in a nonaqueous electrolyte significantly suppresses the reductive decomposition of the electrolyte during high-temperature storage, resulting in a battery with low self-discharge, significantly suppressed deterioration in load characteristics and resistance, and low gas generation within the battery. Patent Document 9 proposes that the use of a sulfonic acid anhydride in an electrolyte improves charge / discharge efficiency and cycle characteristics.

[0004] Japanese Patent No. 2002-008717 Japanese Patent No. 5412705 Japanese Patent No. 3497812 Japanese Patent No. 4847675 Japanese Patent Japanese Patent No. 3439085 Japanese Patent No. 5353923 Japanese Patent No. 3760540 Japanese Patent No. 4190162 Japanese Patent No. 4379567

[0005] Patent Document 1 describes that when the non-aqueous electrolyte contains 0.1 wt % of hydrogen fluoride, the high-temperature storage characteristics of a secondary battery containing the non-aqueous electrolyte are improved. However, the present inventors have found through their studies that the secondary battery described in Patent Document 1 has a problem in that it has high initial resistance.

[0006] The present disclosure has been made in view of the above circumstances, and aims to provide a nonaqueous electrolyte that can reduce the initial resistance of a nonaqueous electrolyte battery, and a nonaqueous electrolyte battery with low initial resistance.

[0007] As a result of intensive research into solving these problems, the present inventors have found that a nonaqueous electrolyte battery with low initial resistance can be provided by reducing the concentration of hydrogen fluoride in a nonaqueous electrolyte solution containing a specific acid anhydride compound, a nonaqueous organic solvent, and a solute to less than one-fifth of the concentration described in Patent Document 1. Specifically, the above problem can be solved by the following configuration.

[0008] [1] A non-aqueous electrolyte solution containing (I) a compound represented by the following general formula (1), (II) a solute, (III) a non-aqueous organic solvent, and hydrogen fluoride, wherein the concentration of the hydrogen fluoride relative to the total amount of the non-aqueous electrolyte solution is 0.1 ppm by mass or more and 180 ppm by mass or less.

[0009]

[0010] In general formula (1), R １ ~R ４ each independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, or an aryl group; X represents an oxygen atom, a sulfur atom, or SO ２ [2] The nonaqueous electrolyte solution according to [1], further comprising (IV) at least one compound selected from the group consisting of the following compounds (2) to (9): Compound (2): At least one compound selected from the group consisting of compounds represented by the following general formula (2-1) and compounds represented by the following general formula (2-2):

[0011]

[0012] In general formula (2-1), R ２１and R ２２ are each independently a fluorine atom, or an organic group selected from an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and the organic group may also contain a fluorine atom, an oxygen atom, or an unsaturated bond. Furthermore, general formula (2-1) contains at least one P-F bond. In general formula (2-2), X ２１ is a fluorine atom, or an organic group selected from an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a cycloalkenyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and the organic group may contain at least one fluorine atom, and the organic group may also contain an oxygen atom or an unsaturated bond. １ ｍ＋ is a proton, a metal cation, or an onium cation. m represents the valence of the corresponding cation. Compound (3): At least one compound selected from the group consisting of compounds represented by the following general formula (3-1), compounds represented by the following general formula (3-2), and compounds represented by the following general formula (3-3).

[0013]

[0014] In general formulas (3-1) to (3-3), R ３１ ~R ３６are each independently a fluorine atom or an organic group selected from an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and the organic group may also contain a fluorine atom, an oxygen atom, or an unsaturated bond. ３１ ~X ３３ are each independently a fluorine atom, or an organic group selected from an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a cycloalkenyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and the organic group may also contain a fluorine atom, an oxygen atom, or an unsaturated bond. General formula (3-1) contains at least one P-F bond. General formula (3-2) contains at least one P-F bond and an S-F bond. General formula (3-3) contains at least one S-F bond. M １ ｍ＋ is a proton, a metal cation, or an onium cation. m represents the valence of the corresponding cation. Compound (4): At least one compound selected from the group consisting of compounds represented by the following general formula (4-1) and compounds represented by the following general formula (4-2):

[0015]

[0016] In general formula (4-1), W １ represents a boron atom, a phosphorus atom, or a silicon atom, n1 is 0 to 3, n2 is 0 to 4, and p is 0 or 1. ４１represents an alkylene group having 1 to 10 carbon atoms, a halogenated alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a halogenated arylene group having 6 to 20 carbon atoms (these groups may contain a substituent or a heteroatom in the structure. When n1 is 2 or more, n1 R ４１ may be bonded to each other), and R ４２ represents a halogen atom, and Y １ and Y ２ each independently represents an oxygen atom or a sulfur atom; Y ３ represents a carbon atom or a sulfur atom. ３ The carbon atom or sulfur atom represented by is bonded with q oxo groups (=O). ３ is 1 when it is a carbon atom, and 1 or 2 when it is a sulfur atom. ａ＋ represents an alkali metal cation, an alkaline earth metal cation, or an onium cation, a represents the valence of the corresponding cation, and a to d are 1 or 2, and a×b=c×d is satisfied.

[0017]

[0018] In general formula (4-2), R ４３ represents an alkylene group having 1 to 10 carbon atoms, a halogenated alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a halogenated arylene group having 6 to 20 carbon atoms (these groups may contain a substituent or a heteroatom in the structure), and r is 0 or 1. Y ４ represents a carbon atom or a sulfur atom. ４ The carbon atom or sulfur atom represented by is bonded with s oxo groups (=O). ４ is 1 when it is a carbon atom, and 1 or 2 when it is a sulfur atom. ２ represents a boron atom or a phosphorus atom, R ４４ represents a halogen atom. n3 represents W ２ When is a boron atom, it is 2, and when is a phosphorus atom, it is 4. Compound (5): A compound represented by the following general formula (5).

[0019]

[0020] In general formula (5), R ５１ R each independently represents a group having a carbon-carbon unsaturated bond. ５２ When a plurality of are present, each independently represents a fluorine atom or an alkyl group having 1 to 10 carbon atoms, and the alkyl group may have at least one of a fluorine atom and an oxygen atom. v represents an integer of 2 to 4. Compound (6): A compound represented by the following general formula (6).

[0021]

[0022] In general formula (6), R ６１ and R ６２ R each independently represents a hydrogen atom, an alkyl group having 1 to 2 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an aryl group having 6 to 10 carbon atoms which may be substituted with an alkyl group. ６１ and R ６２ Any hydrogen atom in the alkyl group, alkenyl group, and aryl group represented by the formula (7-1) may be substituted with a halogen atom. n6 is 0 or 1. Compound (7): At least one compound selected from the group consisting of compounds represented by the following general formula (7-1) and compounds represented by the following general formula (7-2):

[0023]

[0024] In general formula (7-1), R ７０ ~R ７３ each independently represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 5 carbon atoms, or a fluoroalkyl group having 1 to 4 carbon atoms. n71 represents an integer of 1 to 3. In general formula (7-2), R ７４ ~R ７９ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 4 carbon atoms. n72 represents an integer of 0 to 2. Compound (8): A compound represented by the following general formula (8).

[0025]

[0026] In general formula (8), R ８１represents an alkylene group having 1 to 6 carbon atoms, wherein an oxygen atom may be contained between a carbon atom-carbon atom bond in the alkylene group, any hydrogen atom in the alkylene group may be substituted with an alkyl group, and any hydrogen atom in the alkylene group and the alkyl group may be substituted with a halogen atom. Compound (9): A compound represented by the following general formula (9).

[0027]

[0028] In general formula (9), R ９１ and R ９２each independently represent an alkyl group having 1 to 6 carbon atoms. [3] The nonaqueous electrolyte solution according to [1] or [2], wherein the concentration of hydrogen fluoride relative to the total amount of the nonaqueous electrolyte solution is 1 ppm by mass or more and 70 ppm by mass or less. [4] The nonaqueous electrolyte solution according to any one of [1] to [3], wherein the content of (I) relative to the total amount of the nonaqueous electrolyte solution is 0.01% by mass or more and 10% by mass or less. [5] The nonaqueous electrolyte solution according to any one of [1] to [4], wherein the content of (IV) relative to the total amount of the nonaqueous electrolyte solution is 0.01% by mass or more and 10% by mass or less. [6] The nonaqueous electrolyte solution according to any one of [1] to [5], wherein the compound represented by the general formula (1) is at least one compound selected from the group consisting of diglycolic anhydride, methyl diglycolic anhydride, dimethyl diglycolic anhydride, ethyl diglycolic anhydride, vinyl diglycolic anhydride, tetrafluoro diglycolic anhydride, allyl diglycolic anhydride, thiodiacetic anhydride, and sulfodiacetic anhydride. [7] The nonaqueous electrolyte solution according to [2], wherein the compound (2) is at least one compound selected from the group consisting of lithium difluorophosphate, lithium fluorosulfonate, and lithium trifluoromethanesulfonate. [8] The nonaqueous electrolyte solution according to [2], wherein the compound (3) is at least one compound selected from the group consisting of bis(fluorosulfonyl)imide lithium, (fluorosulfonyl)(difluorophosphoryl)imide lithium, bis(trifluoromethanesulfonyl)imide lithium, bis(difluorophosphoryl)imide lithium, bis(pentafluoroethanesulfonyl)imide lithium, and (fluorosulfonyl)(trifluoromethanesulfonyl)imide lithium.[9] The non-aqueous electrolyte solution according to [2], wherein the compound (4) is at least one compound selected from the group consisting of lithium tetrafluoroborate, lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium tris(oxalato)phosphate, lithium difluorobis(oxalato)phosphate, lithium tetrafluoro(oxalato)phosphate, lithium difluoro(malonato)borate, lithium tetrafluoro(malonato)phosphate, tetrafluoro(picolinato)phosphate, and difluoro(picolinato)borate.

[10] The non-aqueous electrolyte solution according to [2], wherein the compound (5) is at least one compound selected from the group consisting of trivinylmethylsilane, trivinylfluorosilane, and tetravinylsilane.

[11] The nonaqueous electrolyte according to [2], wherein the compound (6) is at least one compound selected from the group consisting of 1,3,2-dioxathiolane-2,2-dioxide and 1,3,2-dioxathiane-2,2-dioxide.

[12] The nonaqueous electrolyte according to [2], wherein the compound (8) is at least one compound selected from the group consisting of 1,2-ethanedisulfonic anhydride and 1,3-propanedisulfonic anhydride.

[13] The nonaqueous electrolyte according to [2], wherein the compound (9) is at least one compound selected from the group consisting of methanesulfonic anhydride and ethanesulfonic anhydride.

[14] The nonaqueous electrolyte according to [2], wherein the compound (II) is LiPF. ６ , LiSbF ６ , LiAsF ６ , LiClO ４ , LiAlO ２ , LiAlCl ４ , LiCl and LiI, or NaPF ６ , NaSbF ６ , NaAsF ６ , NaClO ４ , NaAlO ２ , NaAlCl ４, NaCl, and NaI.

[15] The nonaqueous electrolyte solution according to any one of [1] to

[14] , wherein (III) includes at least one selected from the group consisting of a cyclic ester, a chain ester, a cyclic ether, a chain ether, a sulfone compound, a sulfoxide compound, and an ionic liquid.

[16] The nonaqueous electrolyte solution according to

[15] , wherein the cyclic ester is a cyclic carbonate, and the cyclic carbonate is at least one selected from the group consisting of ethylene carbonate, propylene carbonate, and fluoroethylene carbonate.

[17] The nonaqueous electrolyte solution according to

[15] , wherein the chain ester is a chain carbonate, and the chain carbonate is at least one selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, and methyl propyl carbonate.

[18] A nonaqueous electrolyte battery comprising at least a positive electrode, a negative electrode, a separator, and the nonaqueous electrolyte according to any one of [1] to

[17] .

[19] A method for reducing the initial resistance of a nonaqueous electrolyte battery containing a nonaqueous electrolyte, comprising using a nonaqueous electrolyte containing (I) a compound represented by the following general formula (1), (II) a solute, (III) a nonaqueous organic solvent, and hydrogen fluoride as the nonaqueous electrolyte, and adjusting the concentration of the hydrogen fluoride relative to the total amount of the nonaqueous electrolyte to be 0.1 ppm by mass or more and 180 ppm by mass or less:

[0029]

[0030] In general formula (1), R １ ~R ４ each independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, or an aryl group; X represents an oxygen atom, a sulfur atom, or SO ２ Represents a group.

[0031] According to the present disclosure, it is possible to provide a nonaqueous electrolyte that can reduce the initial resistance of a nonaqueous electrolyte battery, and a nonaqueous electrolyte battery with low initial resistance.

[0032] In this specification, the word "to" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0033] The present disclosure will be described in detail below, but the following description of the constituent elements is an example of an embodiment of the present disclosure, and the present disclosure is not limited to these specific contents.

[0034] 1. Regarding the Non-Aqueous Electrolyte The non-aqueous electrolyte of the present disclosure is a non-aqueous electrolyte containing: (I) a compound represented by the following general formula (1); (II) a solute; (III) a non-aqueous organic solvent; and hydrogen fluoride, wherein the concentration of the hydrogen fluoride relative to the total amount of the non-aqueous electrolyte is 0.1 ppm by mass or more and 180 ppm by mass or less.

[0035]

[0036] In general formula (1), R １ ~R ４ each independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, or an aryl group; X represents an oxygen atom, a sulfur atom, or SO ２ Represents a group.

[0037] (I) Compound Represented by General Formula (1) The compound (I) represented by general formula (1) (also referred to as "(I)") contained in the nonaqueous electrolyte solution of the present disclosure will be described. In general formula (1), R １ ~R ４ R each independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, or an aryl group. １ ~R ４ Examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. １ ~R ４ The alkyl group represented by may be linear or branched. The alkyl group may be an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, or an n-hexyl group. Any hydrogen atom in the alkyl group may be substituted with a halogen atom. R １ ~R ４The alkenyl group represented by may be linear or branched. The alkenyl group may be an alkenyl group having 2 to 6 carbon atoms, such as a vinyl group or an allyl group. Any hydrogen atom in the alkenyl group may be substituted with at least one of a halogen atom and an alkyl group. １ ~R ４ The aryl group represented by may be an aryl group having 6 to 20 carbon atoms, such as a phenyl group, a naphthyl group, etc. Any hydrogen atom in the aryl group may be substituted with at least one of a halogen atom and an alkyl group.

[0038] The compound represented by general formula (1) may be a compound selected from the group consisting of diglycolic anhydride, methyldiglycolic anhydride, dimethyldiglycolic anhydride, ethyldiglycolic anhydride, vinyldiglycolic anhydride, tetrafluorodiglycolic anhydride, allyldiglycolic anhydride, thiodiacetic anhydride, and sulfodiacetic anhydride.

[0039] In the nonaqueous electrolyte solution of the present disclosure, as (I), one type of compound may be used alone, or two or more types of compounds may be mixed in any combination and ratio depending on the application.

[0040] The compound represented by formula (1) can be produced by various methods.

[0041] Regarding (II) solute, the solute (II) (also referred to as "(II)") contained in the nonaqueous electrolyte solution of the present disclosure will be described. The solute (II) is not particularly limited, and may be, for example, LiPF ６ , LiSbF ６ , LiAsF ６ , LiClO ４ , LiAlO ２ , LiAlCl ４ , LiCl and LiI, or NaPF ６ , NaSbF ６ , NaAsF ６ , NaClO ４ , NaAlO ２ , NaAlCl ４, NaCl, and NaI.

[0042] In the nonaqueous electrolyte solution of the present disclosure, as (II), one type of compound may be used alone, or two or more types of compounds may be mixed in any combination and ratio depending on the application.

[0043] The concentration of (II) relative to the total amount of the nonaqueous electrolyte is not particularly limited. For example, the lower limit of the concentration of (II) may be 0.5 mol / L or more, 0.7 mol / L or more, or 0.9 mol / L or more. The upper limit of the concentration of (II) may be 5 mol / L or less, 4 mol / L or less, or 2 mol / L or less.

[0044] The liquid temperature when (II) is dissolved in (III) the nonaqueous organic solvent is not particularly limited, but may be from -20 to 80°C or from 0 to 60°C.

[0045] (III) Non-aqueous Organic Solvent The non-aqueous organic solvent (III) (also referred to as "(III)") contained in the non-aqueous electrolyte solution of the present disclosure will be described. The type of non-aqueous organic solvent (III) is not particularly limited, and any non-aqueous organic solvent can be used. Specific examples of the non-aqueous organic solvent (III) include the following non-aqueous organic solvents. Examples of cyclic esters include cyclic carbonates such as propylene carbonate (hereinafter sometimes referred to as "PC"), ethylene carbonate (hereinafter sometimes referred to as "EC"), fluoroethylene carbonate (hereinafter sometimes referred to as "FEC"), and butylene carbonate, as well as γ-butyrolactone and γ-valerolactone. Note that when the content of the FEC relative to the total amount of the non-aqueous electrolyte solution is 10% by mass or less, it is defined as an "other additive" as described below. Examples of chain esters include chain carbonates such as diethyl carbonate (hereinafter sometimes referred to as "DEC"), dimethyl carbonate (hereinafter sometimes referred to as "DMC"), ethyl methyl carbonate (hereinafter sometimes referred to as "EMC"), and methyl propyl carbonate, as well as methyl acetate, methyl propionate, and ethyl propionate (hereinafter sometimes referred to as "EP"). Examples of cyclic ethers include tetrahydrofuran, 2-methyltetrahydrofuran, and dioxane. Examples of chain ethers include dimethoxyethane and diethyl ether. Other examples include sulfone compounds and sulfoxide compounds such as dimethyl sulfoxide and sulfolane. Ionic liquids and the like can also be used.

[0046] (III) The nonaqueous organic solvent may contain at least one selected from the group consisting of cyclic esters, chain esters, cyclic ethers, chain ethers, sulfone compounds, sulfoxide compounds, and ionic liquids.

[0047] The cyclic ester is a cyclic carbonate, and the cyclic carbonate may be at least one selected from the group consisting of ethylene carbonate, propylene carbonate, and fluoroethylene carbonate.

[0048] The chain ester is a chain carbonate, and the chain carbonate may be at least one selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, and methyl propyl carbonate.

[0049] In the nonaqueous electrolyte solution of the present disclosure, as (III), one type of compound may be used alone, or two or more types of compounds may be mixed in any combination and ratio depending on the application.

[0050] The content of the cyclic carbonate is not particularly limited and may be any content as long as it does not significantly impair the effects of the present disclosure. However, when one type is used alone, the content may be 3 vol% or more, more preferably 5 vol% or more, based on 100 vol% of the nonaqueous organic solvent. By setting the content within this range, a decrease in electrical conductivity due to a decrease in the dielectric constant of the nonaqueous electrolyte can be avoided, and the large-current discharge characteristics, stability with respect to the negative electrode, and cycle characteristics of the nonaqueous electrolyte battery can be easily maintained within good ranges. The content may also be 90 vol% or less, preferably 85 vol% or less, and more preferably 80 vol% or less. Setting the content within this range allows the viscosity of the nonaqueous electrolyte to be within an appropriate range, suppresses a decrease in ionic conductivity, and ultimately facilitates the load characteristics of the nonaqueous electrolyte battery to be easily maintained within good ranges.

[0051] Additionally, any combination of two or more cyclic carbonates can be used. One preferred combination is a combination of ethylene carbonate and propylene carbonate. In this case, the volume ratio of ethylene carbonate to propylene carbonate is preferably 99:1 to 40:60, and particularly preferably 95:5 to 50:50. Furthermore, the amount of propylene carbonate relative to the total nonaqueous organic solvent is not particularly limited and may be any amount as long as it does not significantly impair the effects of the present disclosure. However, it may be 1% by volume or more, preferably 2% by volume or more, more preferably 3% by volume or more, or 30% by volume or less, preferably 25% by volume or less, and more preferably 20% by volume or less. The inclusion of propylene carbonate within this range is preferred because it maintains the properties of the combination of ethylene carbonate and dialkyl carbonates while providing even more excellent low-temperature properties.

[0052] The chain ester may be used alone or in any combination and ratio of two or more. The content of the chain ester is not particularly limited, but may be 15% by volume or more, preferably 20% by volume or more, and more preferably 25% by volume or more, based on 100% by volume of the nonaqueous organic solvent. It may also be 90% by volume or less, preferably 85% by volume or less, and more preferably 80% by volume or less. By setting the content of the chain ester within the above range, the viscosity of the nonaqueous electrolyte can be set to an appropriate range, a decrease in ionic conductivity can be suppressed, and the input / output characteristics and charge / discharge rate characteristics of the nonaqueous electrolyte battery can be easily set to good ranges. Furthermore, a decrease in electrical conductivity due to a decrease in the dielectric constant of the nonaqueous electrolyte can be avoided, and the input / output characteristics and charge / discharge rate characteristics of the nonaqueous electrolyte battery can be easily set to good ranges. Furthermore, by combining a specific chain ester with a specific amount of ethylene carbonate, battery performance can be significantly improved.

[0053] For example, when dimethyl carbonate and ethyl methyl carbonate are selected as the specific chain esters, the content of ethylene carbonate is not particularly limited and may be any content as long as it does not significantly impair the effects of the present disclosure, but may be 5% by volume or more, preferably 10% by volume or more, or 45% by volume or less, preferably 40% by volume or less. The content of dimethyl carbonate may be 20% by volume or more, preferably 30% by volume or more, or 50% by volume or less, preferably 45% by volume or less. The content of ethyl methyl carbonate may be 20% by volume or more, preferably 30% by volume or more, or 50% by volume or less, preferably 45% by volume or less. By setting the content within the above range, the low-temperature deposition temperature of the electrolyte is lowered, while also reducing the viscosity of the nonaqueous electrolyte, improving ionic conductivity and allowing high input / output even at low temperatures.

[0054] The content of the chain ether is not particularly limited and may be any amount as long as it does not significantly impair the effects of the present disclosure. It may be 1% by volume or more, preferably 2% by volume or more, more preferably 3% by volume or more, or 30% by volume or less, preferably 25% by volume or less, more preferably 20% by volume or less, based on 100% by volume of the nonaqueous organic solvent. When the content of the chain ether is within the above range, it is easy to ensure the effect of improving the degree of lithium ion dissociation of the chain ether and improving ionic conductivity due to reduced viscosity. Furthermore, when the negative electrode active material is a carbonaceous material, the phenomenon of co-insertion of the chain ether with lithium ions can be suppressed, thereby allowing the input / output characteristics and charge / discharge rate characteristics to be within appropriate ranges.

[0055] The content of the sulfone compound is not particularly limited and may be any content as long as it does not significantly impair the effects of the present disclosure, but may be 0.3 vol% or more, preferably 0.5 vol% or more, more preferably 1 vol% or more, or 40 vol% or less, preferably 35 vol% or less, more preferably 30 vol% or less, relative to 100 vol% of the nonaqueous organic solvent. If the content of the sulfone compound is within the above range, it is easy to obtain an effect of improving durability such as cycle characteristics and storage characteristics, and it is also possible to keep the viscosity of the nonaqueous electrolyte within an appropriate range, avoid a decrease in electrical conductivity, and keep the input / output characteristics and charge / discharge rate characteristics of the nonaqueous electrolyte battery within appropriate ranges.

[0056] Regarding the hydrogen fluoride concentration, the hydrogen fluoride concentration relative to the total amount of the nonaqueous electrolyte is 0.1 mass ppm (parts per million) or more and 180 mass ppm or less. By having the hydrogen fluoride concentration relative to the total amount of the nonaqueous electrolyte within the above range, the initial resistance of the nonaqueous electrolyte battery can be reduced. The lower limit of the hydrogen fluoride concentration relative to the total amount of the nonaqueous electrolyte may be 0.5 mass ppm or more, or may be 1 mass ppm or more. Furthermore, the upper limit of the hydrogen fluoride concentration relative to the total amount of the nonaqueous electrolyte may be 120 mass ppm or less, 70 mass ppm or less, or 50 mass ppm or less.

[0057] (IV) At least one compound selected from the group consisting of compounds (2) to (9) The nonaqueous electrolyte solution of the present disclosure may further contain (IV) at least one compound selected from the group consisting of the following compounds (2) to (9) (also referred to as "(IV)"). By further containing (IV), the nonaqueous electrolyte solution of the present disclosure can further reduce the initial resistance of a nonaqueous electrolyte battery.

[0058] Compound (2): At least one compound selected from the group consisting of compounds represented by the following general formula (2-1) and compounds represented by the following general formula (2-2):

[0059]

[0060] In general formula (2-1), R ２１ and R ２２ are each independently a fluorine atom, or an organic group selected from an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and the organic group may also contain a fluorine atom, an oxygen atom, or an unsaturated bond. Furthermore, general formula (2-1) contains at least one P-F bond. In general formula (2-2), X ２１ is a fluorine atom, or an organic group selected from an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a cycloalkenyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and the organic group may contain at least one fluorine atom, and the organic group may also contain an oxygen atom or an unsaturated bond. １ ｍ＋is a proton, a metal cation or an onium cation, and m represents the valence of the corresponding cation.

[0061] In general formula (2-1), R ２１ and R ２２ The alkoxy group represented by may be linear or branched. Examples of the alkoxy group include alkoxy groups having 1 to 10 carbon atoms and fluorine-containing alkoxy groups such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, a trifluoromethoxy group, a 2,2-difluoroethoxy group, a 2,2,2-trifluoroethoxy group, a 2,2,3,3-tetrafluoropropoxy group, a 1,1,1-trifluoroisopropoxy group, and a 1,1,1,3,3,3-hexafluoroisopropoxy group. R ２１ and R ２２ The alkenyloxy group represented by the formula (I) may be linear or branched. Examples of the alkenyloxy group include alkenyloxy groups having 2 to 10 carbon atoms, such as vinyloxy group, 1-propenyloxy group, 2-propenyloxy group, isopropenyloxy group, 2-butenyloxy group, 3-butenyloxy group, and 1,3-butadienyloxy group, and fluorine-containing alkenyloxy groups. R ２１ and R ２２ The alkynyloxy group represented by the formula (I) may be linear or branched. Examples of the alkynyloxy group include alkynyloxy groups having 2 to 10 carbon atoms, such as ethynyloxy, 2-propynyloxy, and 1,1-dimethyl-2-propynyloxy, and fluorine-containing alkynyloxy groups. ２１ and R ２２ Examples of the cycloalkoxy group represented by the formula (R) include cycloalkoxy groups having 3 to 10 carbon atoms, such as a cyclopentyloxy group and a cyclohexyloxy group, and fluorine-containing cycloalkoxy groups. ２１ and R ２２Examples of the cycloalkenyloxy group represented by the formula (R) include cycloalkenyloxy groups having 3 to 10 carbon atoms, such as a cyclopentenyloxy group and a cyclohexenyloxy group, and fluorine-containing cycloalkenyloxy groups. ２１ and R ２２ Examples of the aryloxy group represented by the formula (I) include aryloxy groups having 6 to 10 carbon atoms, such as a phenyloxy group, a tolyloxy group, and a xylyloxy group, and fluorine-containing aryloxy groups.

[0062] R ２１ and R ２２ are each independently a fluorine atom or an alkoxy group having a fluorine atom, which is preferable because the degree of ionic dissociation is improved due to its strong electron-withdrawing property, thereby increasing the ionic conductivity in a solution or a composition. Furthermore, a fluorine atom is even more preferable because the anion size is reduced, which improves mobility, thereby significantly increasing the ionic conductivity in a solution or a composition. ２１ and R ２２ The number of carbon atoms is preferably 6 or less. When the number of carbon atoms is 6 or less, the ionic conductivity tends to be relatively high, which is preferable.

[0063] In general formula (2-1), M １ ｍ＋ represents a proton, a metal cation, or an onium cation. There are no particular limitations on the type of the cation, and various cations can be selected from the above, as long as they do not impair the performance of the nonaqueous electrolyte and nonaqueous electrolyte battery of the present disclosure.

[0064] M １ ｍ＋ When M represents a metal cation, examples of the metal cation include alkali metal cations such as lithium ion, sodium ion, potassium ion, rubidium ion, and cesium ion, alkaline earth metal cations such as magnesium ion, calcium ion, and barium ion, silver ion, copper ion, and iron ion. １ ｍ＋When represents an onium cation, examples of the onium cation include onium cations such as tetraalkylammonium, tetraalkylphosphonium, and imidazolium derivatives. m represents the valence of the corresponding cation, and may be 1 to 3, or may be 1 or 2.

[0065] M １ ｍ＋ In particular, from the viewpoint of helping ion conduction in a non-aqueous electrolyte battery, lithium ions, sodium ions, potassium ions, tetramethylammonium ions, tetraethylammonium ions, tetrabutylphosphonium ions, etc. are preferred. １ ｍ＋ When used in a lithium ion battery, the charge carrier is more preferably a lithium ion, and when used in a sodium ion battery, the charge carrier is more preferably a sodium ion.

[0066] Specific examples of the anion structure of the compound represented by formula (2-1) are shown below, but are not limited to these.

[0067]

[0068] In general formula (2-2), X ２１ The alkyl group represented by the formula (I) may be linear or branched. Examples of the alkyl group include alkyl groups having 1 to 10 carbon atoms and fluorine-containing alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a trifluoromethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a 2,2,3,3-tetrafluoropropyl group, and a 1,1,1,3,3,3-hexafluoroisopropyl group. X ２１ The alkenyl group represented by the formula (X) may be linear or branched. Examples of the alkenyl group include alkenyl groups having 2 to 10 carbon atoms, such as vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 2-butenyl group, 3-butenyl group, and 1,3-butadienyl group, and fluorine-containing alkenyl groups. ２１The alkynyl group represented by the formula (I) may be linear or branched. Examples of the alkynyl group include alkynyl groups having 2 to 10 carbon atoms, such as ethynyl, 2-propynyl, and 1,1-dimethyl-2-propynyl, and fluorine-containing alkynyl groups. X ２１ Examples of the cycloalkyl group represented by the formula (X) include cycloalkyl groups having 3 to 10 carbon atoms, such as a cyclopentyl group and a cyclohexyl group, and fluorine-containing cycloalkyl groups. ２１ Examples of the cycloalkenyl group represented by X include cycloalkenyl groups having 3 to 10 carbon atoms, such as a cyclopentenyl group and a cyclohexenyl group, and fluorine-containing cycloalkenyl groups; ２１ Examples of the aryl group represented by X include aryl groups having 6 to 10 carbon atoms, such as a phenyl group, a tolyl group, and a xylyl group, and fluorine-containing aryl groups. ２１ The alkoxy group, alkenyloxy group, alkynyloxy group, cycloalkoxy group, cycloalkenyloxy group, and aryloxy group represented by the formula (2-1) are R ２１ and R ２２ Examples of the alkoxy group include an alkoxy group, an alkenyloxy group, an alkynyloxy group, a cycloalkoxy group, a cycloalkenyloxy group, and an aryloxy group represented by the following formula:

[0069] In general formula (2-2), X ２１ is preferably a fluorine atom or an alkyl group containing a fluorine atom, since the degree of ionic dissociation is improved due to its strong electron-withdrawing property, thereby increasing the ionic conductivity in a solution or a composition. Furthermore, a fluorine atom is more preferable, since the anion size is reduced, thereby improving the mobility, thereby significantly increasing the ionic conductivity in a solution or a composition. ２１ When the number of carbon atoms is 6 or less, the ionic conductivity tends to be relatively high, so it is preferable, the number of carbon atoms is more preferably 1 to 4, and the number of carbon atoms is still more preferably 1 to 3. Specific examples include a trifluoromethyl group, a trifluoromethoxy group, and a trifluoroethoxy group, and a trifluoromethyl group having a small anion size is particularly preferable.

[0070] In general formula (2-2), M １ ｍ＋ represents M in general formula (2-1). １ ｍ＋ The same applies to specific examples and preferred examples.

[0071] Specific examples of the anion structure of the compound represented by formula (2-2) are shown below, but are not limited to these.

[0072]

[0073] Compound (2) is preferably at least one compound selected from the group consisting of difluorophosphates, fluorosulfonates, and trifluoromethanesulfonates, and more preferably at least one compound selected from the group consisting of lithium difluorophosphate, lithium fluorosulfonate, and lithium trifluoromethanesulfonate.

[0074] Compound (3): At least one compound selected from the group consisting of a compound represented by the following general formula (3-1), a compound represented by the following general formula (3-2), and a compound represented by the following general formula (3-3):

[0075]

[0076] In general formulas (3-1) to (3-3), R ３１ ~R ３６ are each independently a fluorine atom or an organic group selected from an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and the organic group may also contain a fluorine atom, an oxygen atom, or an unsaturated bond. ３１ ~X ３３are each independently a fluorine atom, or an organic group selected from an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a cycloalkenyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and the organic group may also contain a fluorine atom, an oxygen atom, or an unsaturated bond. General formula (3-1) contains at least one P-F bond. General formula (3-2) contains at least one P-F bond and an S-F bond. General formula (3-3) contains at least one S-F bond. M １ ｍ＋ is a proton, a metal cation or an onium cation, and m represents the valence of the corresponding cation.

[0077] R ３１ ~R ３６ The alkoxy group, alkenyloxy group, alkynyloxy group, cycloalkoxy group, cycloalkenyloxy group and aryloxy group represented by the formula (2-1) are R ２１ and R ２２ Examples of the alkoxy group include an alkoxy group, an alkenyloxy group, an alkynyloxy group, a cycloalkoxy group, a cycloalkenyloxy group, and an aryloxy group represented by the following formula:

[0078] R ３１ ~R ３６ are each independently a fluorine atom or an alkoxy group having a fluorine atom, which is preferable because the degree of ionic dissociation is improved due to its strong electron-withdrawing property, thereby increasing the ionic conductivity in a solution or a composition. Furthermore, a fluorine atom is even more preferable because the anion size is reduced, which improves mobility, thereby significantly increasing the ionic conductivity in a solution or a composition. ３１ ~R ３６The number of carbon atoms is preferably 6 or less. When the number of carbon atoms is 6 or less, the ionic conductivity tends to be relatively high, which is preferable.

[0079] X ３１ ~X ３３ Examples of the alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group, aryl group, alkoxy group, alkenyloxy group, alkynyloxy group, cycloalkoxy group, cycloalkenyloxy group and aryloxy group represented by the formula (2-2) include X ２１ Examples of the alkyl group include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, an alkoxy group, an alkenyloxy group, an alkynyloxy group, a cycloalkoxy group, a cycloalkenyloxy group, and an aryloxy group represented by the following formula:

[0080] X ３１ ~X ３３ is preferably a fluorine atom or an alkyl group containing a fluorine atom, since the degree of ionic dissociation is improved due to its strong electron-withdrawing property, thereby increasing the ionic conductivity in a solution or a composition. Furthermore, a fluorine atom is more preferable, since the anion size is reduced, thereby improving the mobility, thereby significantly increasing the ionic conductivity in a solution or a composition. ３１ ~X ３３ When the number of carbon atoms is 6 or less, the ionic conductivity tends to be relatively high, so it is preferable, the number of carbon atoms is more preferably 1 to 4, and the number of carbon atoms is still more preferably 1 to 3. Specific examples include a trifluoromethyl group and a pentafluoroethyl group, and a trifluoromethyl group having a small anion size is particularly preferable.

[0081] In general formulas (3-1) to (3-3), M １ ｍ＋ represents M in general formula (2-1). １ ｍ＋ The same applies to specific examples and preferred examples.

[0082] Specific examples of the anion structure of the compound represented by any one of general formulas (3-1) to (3-3) are shown below, but are not limited to these.

[0083]

[0084]

[0085]

[0086] Compound (3) is preferably at least one compound selected from the group consisting of bis(fluorosulfonyl)imide salts, (fluorosulfonyl)(difluorophosphoryl)imide salts, bis(trifluoromethanesulfonyl)imide salts, bis(difluorophosphoryl)imide salts, bis(pentafluoroethanesulfonyl)imide salts, and (fluorosulfonyl)(trifluoromethanesulfonyl)imide salts, and more preferably at least one compound selected from the group consisting of bis(fluorosulfonyl)imide lithium, (fluorosulfonyl)(difluorophosphoryl)imide lithium, bis(trifluoromethanesulfonyl)imide lithium, bis(difluorophosphoryl)imide lithium, bis(pentafluoroethanesulfonyl)imide lithium, and (fluorosulfonyl)(trifluoromethanesulfonyl)imide lithium.

[0087] Compound (4): At least one compound selected from the group consisting of compounds represented by the following general formula (4-1) and compounds represented by the following general formula (4-2):

[0088]

[0089] In general formula (4-1), W １ represents a boron atom, a phosphorus atom, or a silicon atom, n1 is 0 to 3, n2 is 0 to 4, and p is 0 or 1. ４１ represents an alkylene group having 1 to 10 carbon atoms, a halogenated alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a halogenated arylene group having 6 to 20 carbon atoms (these groups may contain a substituent or a heteroatom in the structure. When n1 is 2 or more, n1 R ４１ may be bonded to each other), and R ４２ represents a halogen atom, and Y １ and Y２ each independently represents an oxygen atom or a sulfur atom; Y ３ represents a carbon atom or a sulfur atom. ３ The carbon atom or sulfur atom represented by is bonded with q oxo groups (=O). ３ is 1 when it is a carbon atom, and 1 or 2 when it is a sulfur atom. ａ＋ represents an alkali metal cation, an alkaline earth metal cation, or an onium cation, a represents the valence of the corresponding cation, and a to d are 1 or 2, and a×b=c×d is satisfied.

[0090] W １ represents a boron atom, a phosphorus atom or a silicon atom, and is preferably a boron atom or a phosphorus atom.

[0091] R ４１ The alkylene group represented by the formula (R) may be linear or branched. Examples of the alkylene group include alkylene groups having 1 to 10 carbon atoms, such as methylene, ethylene, n-propylene, isopropylene, n-butylene, and n-hexylene. ４１ Examples of the halogenated alkylene group having 1 to 10 carbon atoms represented by the formula (R) include groups in which any hydrogen atom in the alkylene group has been substituted with a halogen atom. ４１ Examples of the arylene group having 6 to 20 carbon atoms represented by the formula (R) include a phenylene group and a naphthylene group. ４１ Examples of the halogenated arylene group having 6 to 20 carbon atoms represented by the formula (I) include groups in which any hydrogen atom of the above arylene group has been substituted with a halogen atom.

[0092] R ４１ As the alkyl group, a methylene group, an ethylene group, an n-propylene group, a difluoromethylene group, a tetrafluoroethylene group, or a hexafluoropropylene group is preferred, and a methylene group is more preferred.

[0093] R ４２ Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, and an iodine atom, with a fluorine atom being preferred.

[0094] Y １ and Y ２each independently represents an oxygen atom or a sulfur atom, and it is preferable that all of them are oxygen atoms.

[0095] Y ３ represents a carbon atom or a sulfur atom, and is preferably a carbon atom.

[0096] M ａ＋ Examples of the alkali metal cation, alkaline earth metal cation and onium cation represented by the formula (2-1) include M １ ｍ＋ Examples of the cations include the alkali metal cations, alkaline earth metal cations and onium cations listed above, and specific examples and preferred examples are also the same.

[0097] Examples of the compound represented by general formula (4-1) include tetrafluoroborate, bis(oxalato)borate, difluoro(oxalato)borate, tris(oxalato)phosphate, difluorobis(oxalato)phosphate, tetrafluoro(oxalato)phosphate, tris(oxalato)silicate, difluorobis(oxalato)silicate, difluoro(malonato)borate, tetrafluoro(malonato)phosphate, difluoro(sulfoacetato)borate, difluoro(maleato)borate, and difluoro(fumarato)borate.

[0098] Compound (4) is preferably at least one compound selected from the group consisting of tetrafluoroborate, bis(oxalato)borate, difluoro(oxalato)borate, tris(oxalato)phosphate, difluorobis(oxalato)phosphate, tetrafluoro(oxalato)phosphate, difluoro(malonato)borate, and tetrafluoro(malonato)phosphate, and more preferably at least one compound selected from the group consisting of lithium tetrafluoroborate, lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium tris(oxalato)phosphate, lithium difluorobis(oxalato)phosphate, lithium tetrafluoro(oxalato)phosphate, lithium difluoro(malonato)borate, and lithium tetrafluoro(malonato)phosphate.

[0099]

[0100] In general formula (4-2), R ４３ represents an alkylene group having 1 to 10 carbon atoms, a halogenated alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a halogenated arylene group having 6 to 20 carbon atoms (these groups may contain a substituent or a heteroatom in the structure), and r is 0 or 1. Y ４ represents a carbon atom or a sulfur atom. ４ The carbon atom or sulfur atom represented by is bonded with s oxo groups (=O). ４ is 1 when it is a carbon atom, and 1 or 2 when it is a sulfur atom. ２ represents a boron atom or a phosphorus atom, R ４４ represents a halogen atom. n3 represents W ２ is 2 for boron atoms and 4 for phosphorus atoms.

[0101] R ４３ The alkylene group represented by the formula (R) may be linear or branched. Examples of the alkylene group include alkylene groups having 1 to 10 carbon atoms, such as methylene, ethylene, n-propylene, isopropylene, n-butylene, and n-hexylene. ４３ Examples of the halogenated alkylene group having 1 to 10 carbon atoms represented by the formula (R) include groups in which any hydrogen atom in the alkylene group has been substituted with a halogen atom. ４３ Examples of the arylene group having 6 to 20 carbon atoms represented by the formula (R) include a phenylene group and a naphthylene group. ４３ Examples of the halogenated arylene group having 6 to 20 carbon atoms represented by the formula (I) include groups in which any hydrogen atom of the above arylene group has been substituted with a halogen atom.

[0102] R ４３ As the alkyl group, a methylene group, an ethylene group, an n-propylene group, a difluoromethylene group, a tetrafluoroethylene group, or a hexafluoropropylene group is preferred, and a methylene group is more preferred.

[0103] R ４４Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, and an iodine atom, with a fluorine atom being preferred.

[0104] Y ４ represents a carbon atom or a sulfur atom, and is preferably a carbon atom.

[0105] Examples of the compound represented by formula (4-2) include the following compounds (4-2-a) to (4-2-d), with compound (4-2-a) being preferred.

[0106]

[0107] Compound (5): A compound represented by the following general formula (5).

[0108]

[0109] In general formula (5), R ５１ R each independently represents a group having a carbon-carbon unsaturated bond. ５２ When a plurality of are present, each independently represents a fluorine atom or an alkyl group having 1 to 10 carbon atoms, and the alkyl group may have at least one of a fluorine atom and an oxygen atom. v represents an integer of 2 to 4.

[0110] R ５１The group having a carbon-carbon unsaturated bond represented by the formula (I) may be linear or branched. Examples of the group having a carbon-carbon unsaturated bond include alkenyl groups having 2 to 8 carbon atoms, such as vinyl, allyl, 1-propenyl, isopropenyl, 2-butenyl, and 1,3-butadienyl, or alkenyloxy groups derived from these groups; alkynyl groups having 2 to 8 carbon atoms, such as ethynyl, 2-propynyl, and 1,1-dimethyl-2-propynyl, or alkynyloxy groups derived from these groups; aryl groups having 6 to 12 carbon atoms, such as phenyl, tolyl, and xylyl, or aryloxy groups derived from these groups. The above groups may also contain fluorine atoms and oxygen atoms. Among these, groups containing a carbon-carbon unsaturated bond having 6 or less carbon atoms are preferred. If the number of carbon atoms is 6 or less, the resistance when a coating is formed on an electrode tends to be relatively low. Specifically, groups selected from the group consisting of vinyl, allyl, 1-propenyl, ethynyl and 2-propynyl groups are preferred.

[0111] R ５２ When there are a plurality of R's, each independently represents a fluorine atom or an alkyl group having 1 to 10 carbon atoms. ５２ The alkyl group represented by the formula (I) may be linear or branched. Examples of the alkyl group include alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, and n-pentyl. The above groups may also contain at least one of a fluorine atom and an oxygen atom.

[0112] Among these, groups selected from a fluorine atom, a methyl group, an ethyl group, a propyl group, a 2,2,2-trifluoroethyl group, a 2,2,3,3-tetrafluoropropyl group, a 1,1,1-trifluoroisopropyl group, and a 1,1,1,3,3,3-hexafluoroisopropyl group tend to have a smaller initial resistance when a film is formed on an electrode, and as a result are preferred from the viewpoint of output characteristics.

[0113] In formula (5), v represents an integer of 2 to 4, preferably 3 or 4, and particularly preferably 4.

[0114] Specific examples of the compound represented by formula (5) are shown below, but the invention is not limited to these.

[0115]

[0116] The compound (5) is preferably at least one compound selected from the group consisting of trivinylmethylsilane, trivinylfluorosilane, and tetravinylsilane.

[0117] Compound (6): A compound represented by the following general formula (6).

[0118]

[0119] In general formula (6), R ６１ and R ６２ R each independently represents a hydrogen atom, an alkyl group having 1 to 2 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an aryl group having 6 to 10 carbon atoms which may be substituted with an alkyl group. ６１ and R ６２ Any hydrogen atom in the alkyl group, alkenyl group, or aryl group represented by the formula (I) may be substituted with a halogen atom. n6 is 0 or 1.

[0120] R ６１ and R ６２ When R is an alkyl group having 1 to 2 carbon atoms, examples of the alkyl group include a methyl group and an ethyl group. ６１ and R ６２ However, when R is an alkenyl group having 2 to 5 carbon atoms, the alkenyl group may be linear or branched. Examples of the alkenyl group include a vinyl group, an allyl group, a 1-propenyl group, an isopropenyl group, a 2-butenyl group, and a 1,3-butadienyl group. ６１ and R ６２ However, when the aryl group is an aryl group having 6 to 10 carbon atoms which may be substituted with an alkyl group, examples of the aryl group include a phenyl group, a tolyl group, and a xylyl group.

[0121] At least one of the hydrogen atoms in the alkyl group, alkenyl group, and aryl group may be substituted with a halogen atom, such as a fluorine atom, a bromine atom, or an iodine atom, with a fluorine atom being preferred.

[0122] R ６１ and R ６２ preferably represents a hydrogen atom. When n6 is 0, R ６１ and the carbon atom to which R is bonded. ６２ is bonded to the carbon atom to which it is bonded via a single bond. Compound (6) is preferably at least one compound selected from the group consisting of 1,3,2-dioxathiolane-2,2-dioxide and 1,3,2-dioxathiane-2,2-dioxide.

[0123] Specific examples of the compound represented by formula (6) are shown below, but the invention is not limited to these.

[0124]

[0125] Compound (7): At least one compound selected from the group consisting of compounds represented by the following general formula (7-1) and compounds represented by the following general formula (7-2):

[0126]

[0127] In general formula (7-1), R ７０ ~R ７３ each independently represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 5 carbon atoms, or a fluoroalkyl group having 1 to 4 carbon atoms. n71 represents an integer of 1 to 3. In general formula (7-2), R ７４ ~R ７９ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 4 carbon atoms. n72 represents an integer of 0 to 2.

[0128] In general formula (7-1), R ７０ ~R ７３The alkyl group represented by the formula (I) may be linear or branched, and examples thereof include alkyl groups having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, and an n-pentyl group.

[0129] R ７０ ~R ７３ The fluoroalkyl group represented by the formula (I) may be linear or branched, and examples thereof include fluoroalkyl groups having 1 to 4 carbon atoms, such as a trifluoromethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a 2,2,3,3-tetrafluoropropyl group, and a 1,1,1,3,3,3-hexafluoroisopropyl group.

[0130] R ７０ ~R ７３ is preferably a hydrogen atom, a fluorine atom or a trifluoromethyl group, more preferably a hydrogen atom.

[0131] In the general formula (7-1), n71 represents an integer of 1 to 3, may be 1 or 2, and is preferably 1.

[0132] Examples of the compound represented by general formula (7-1) include 1,3-propene sultone (1-propene-1,3-sultone), 1,4-butene sultone, 2,4-pentene sultone, 3,5-pentene sultone, 1-fluoro-1,3-propene sultone, 1-trifluoromethyl-1,3-propene sultone, 1,1,1-trifluoro-2,4-butene sultone, 1,4-butene sultone, and 1,5-pentene sultone.

[0133] In general formula (7-2), R ７４ ~R ７９ The alkyl group represented by the formula (I) may be linear or branched, and examples thereof include alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, and n-hexyl.

[0134] R ７４ ~R ７９The fluoroalkyl group represented by the formula (I) may be linear or branched, and examples thereof include fluoroalkyl groups having 1 to 4 carbon atoms, such as a trifluoromethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a 2,2,3,3-tetrafluoropropyl group, and a 1,1,1,3,3,3-hexafluoroisopropyl group.

[0135] R ７４ ~R ７９ is preferably a hydrogen atom, a fluorine atom or a trifluoromethyl group, more preferably a hydrogen atom.

[0136] In the general formula (7-2), n72 represents an integer of 0 to 2, and may be 0 or 1, and is preferably 0. When n72 is 0, R ７６ and R ７７ and the carbon atom to which R is bonded. ７８ and R ７９ is bonded to the carbon atom to which it is bonded by a single bond.

[0137] Examples of the compound represented by general formula (7-2) include 1,3-propane sultone, α-trifluoromethyl-γ-sultone, β-trifluoromethyl-γ-sultone, γ-trifluoromethyl-γ-sultone, α-methyl-γ-sultone, α,β-di(trifluoromethyl)-γ-sultone, α,α-di(trifluoromethyl)-γ-sultone, α-heptafluoropropyl-γ-sultone, 1,4-butane sultone, and 1,5-pentane sultone.

[0138] Compound (7) is preferably at least one compound selected from the group consisting of 1,3-propane sultone and 1-propene 1,3-sultone.

[0139] Compound (8): A compound represented by the following general formula (8).

[0140]

[0141] In general formula (8), R ８１represents an alkylene group having 1 to 6 carbon atoms, and an oxygen atom may be contained between a carbon atom-carbon atom bond in the alkylene group, any hydrogen atom in the alkylene group may be substituted with an alkyl group, and any hydrogen atom in the alkylene group and the alkyl group may be substituted with a halogen atom.

[0142] R ８１ The alkylene group having 1 to 6 carbon atoms represented by the formula (I) may be linear or branched, and examples thereof include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, and an n-hexylene group.

[0143] The compound (8) is preferably at least one compound selected from the group consisting of 1,2-ethanedisulfonic anhydride and 1,3-propanedisulfonic anhydride.

[0144] Compound (9): A compound represented by the following general formula (9).

[0145]

[0146] In general formula (9), R ９１ and R ９２ each independently represents an alkyl group having 1 to 6 carbon atoms.

[0147] R ９１ and R ９２ The alkyl group having 1 to 6 carbon atoms represented by the formula (I) may be linear or branched, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, and an n-pentyl group.

[0148] The compound (9) is preferably at least one compound selected from the group consisting of methanesulfonic anhydride and ethanesulfonic anhydride.

[0149] In the nonaqueous electrolyte solution of the present disclosure, one type of compound may be used alone as (IV), or two or more types of compounds may be mixed in any combination and ratio depending on the application.

[0150] In the nonaqueous electrolyte solution of the present disclosure, the content of (I) (also referred to as the "concentration of (I)") relative to the total amount of the nonaqueous electrolyte solution may be 0.01% by mass or more and 10% by mass or less. The lower limit of the concentration of (I) may be 0.08% by mass or more, 0.3% by mass or more, or 0.8% by mass or more. The upper limit of the concentration of (I) may be 8% by mass or less, 5% by mass or less, 4% by mass or less, 3% by mass or less, or 1.5% by mass or less.

[0151] In the nonaqueous electrolyte solution of the present disclosure, the content of (IV) (also referred to as "concentration of (IV)") relative to the total amount of the nonaqueous electrolyte solution may be 0.01 mass % or more and 10 mass % or less. The lower limit of the concentration of (IV) may be 0.08 mass % or more, 0.1 mass % or more, or 0.2 mass % or more. The upper limit of the concentration of (IV) may be 8 mass % or less, 6 mass % or less, or 5 mass % or less. Note that LiN(CF ３ SO ２ ) ２ , LiN(FSO ２ ) ２ , LiN (POF ２ ) ２ , LiCF ３ SO ３ , LiC ４ F ９ SO ３ , NaN(CF ３ SO ２ ) ２ , NaN(FSO ２ ) ２ , NaN(POF ２ ) ２ , NaCF ３ SO ３ , NaC ４ F ９ SO ３ The content of the non-aqueous electrolyte may be 0.01 mass % or more and 20 mass % or less relative to the total amount of the non-aqueous electrolyte.

[0152] While the basic structure of the nonaqueous electrolyte solution of the present disclosure has been described above, additives that are commonly used in the nonaqueous electrolyte solution of the present disclosure may be added in any proportion as long as the gist of the present disclosure is not impaired. When the nonaqueous electrolyte solution of the present disclosure contains other additives, the content of the other additives may be 0.01% by mass or more and 10.0% by mass or less with respect to the total amount of the nonaqueous electrolyte solution.

[0153] Specific examples of other additives include vinylene carbonate (hereinafter sometimes referred to as "VC"), vinylene carbonate oligomer (having a polystyrene-equivalent number average molecular weight of 170 to 5000), fluoroethylene carbonate, trans-difluoroethylene carbonate, 1,6-diisocyanatohexane, ethynylethylene carbonate, methylenemethane disulfonate, methanesulfonyl fluoride, tris(trimethylsilyl)borate, (ethoxy)pentafluorocyclotriphosphazene, 1,3-dimethyl-1,3-divinyl-1,3-di(1,1,1,3,3,3-hexafluoroisopropyl)disiloxane, tert-butylbenzene, tert-amylbenzene, fluorobenzene, cyclohexylbenzene, biphenyl, difluoroanisole, dimethylvinylene carbonate, and nitrates. By adding the above-described additives to the nonaqueous electrolyte solution of the present disclosure, at least one of the overcharge prevention effect, the negative electrode film formation effect, and the positive electrode protection effect may be enhanced.

[0154] The nonaqueous electrolyte of the present disclosure is suitable for use in nonaqueous electrolyte batteries (preferably nonaqueous electrolyte secondary batteries).

[0155] 2. Regarding the Non-Aqueous Electrolyte Battery The non-aqueous electrolyte battery of the present disclosure includes at least the non-aqueous electrolyte of the present disclosure, a negative electrode, and a positive electrode. It may also include a separator, an exterior body, and the like. The non-aqueous electrolyte battery of the present disclosure preferably includes at least a positive electrode, a negative electrode, a separator, and the non-aqueous electrolyte of the present disclosure. The non-aqueous electrolyte battery of the present disclosure is preferably a non-aqueous electrolyte secondary battery.

[0156] The negative electrode is not particularly limited, but may be made of a material that allows reversible insertion and desorption of alkali metal ions such as lithium ions and sodium ions, or alkaline earth metal ions.

[0157] For example, in the case of a lithium-ion secondary battery in which the cation is mainly lithium, the negative electrode active material constituting the negative electrode is capable of doping and dedoping lithium ions. For example, carbon materials having a d value of the (002) lattice plane in X-ray diffraction of 0.340 nm or less, carbon materials having a d value of the (002) lattice plane in X-ray diffraction of more than 0.340 nm, oxides of one or more metals selected from Si, Sn, and Al, alloys containing one or more metals selected from Si, Sn, and Al, or alloys of these metals or alloys with lithium, and lithium titanium oxide. These negative electrode active materials can be used alone or in combination of two or more. Lithium metal, metal nitrides, tin compounds, conductive polymers, etc. may also be used.

[0158] For example, in the case of a sodium-ion secondary battery in which the cation is primarily sodium, the negative electrode active material constituting the negative electrode may be sodium metal, an alloy of sodium metal with other metals such as tin, an intermetallic compound of sodium metal with other metals, various carbon materials such as hard carbon, metal oxides such as titanium oxide, metal nitrides, tin (simple substance), tin compounds, activated carbon, conductive polymers, etc. In addition to these, phosphorus (simple substance) such as red phosphorus and black phosphorus, phosphorus compounds such as Co—P, Cu—P, Sn—P, Ge—P, and Mo—P, antimony (simple substance), antimony compounds such as Sb / C and Bi—Sb, etc., may also be used. These negative electrode active materials may be used alone or in combination of two or more types.

[0159] The positive electrode is not particularly limited, but may be made of a material that allows reversible insertion and desorption of alkali metal ions such as lithium ions and sodium ions, or alkaline earth metal ions.

[0160] For example, when the cation is lithium, the positive electrode material is LiCoO ２ , LiNiO２ , LiMnO ２ , LiMn ２ O ４ Lithium-containing transition metal composite oxides such as those described above, in which a plurality of transition metals such as Co, Mn, and Ni are mixed, those in which a part of the transition metal in the lithium-containing transition metal composite oxide is replaced with a metal other than the transition metal, and LiFePO , which is called olivine. ４ , LiCoPO ４ , LiMnPO ４ transition metal phosphate compounds such as TiO ２ , V ２ O ５ , MoO ３ oxides such as TiS ２ , sulfides such as FeS, conductive polymers such as polyacetylene, polyparaphenylene, polyaniline, and polypyrrole, activated carbon, radical-generating polymers, carbon materials, etc. may also be used. １／３ Mn １／３ Co １／３ ]O ２ , Li[Ni ０．４５ Mn ０．３５ Co ０．２ ]O ２ , Li[Ni ０．５ Mn ０．３ Co ０．２ ]O ２ , Li[Ni ０．６ Mn ０．２ Co ０．２ ]O ２ , Li[Ni ０．８ Mn ０．１ Co ０．１ ]O ２ (hereinafter, sometimes referred to as "NCM811"), Li[Ni ０．４９ Mn ０．３ Co ０．２ Zr ０．０１ ]O ２ , Li[Ni ０．４９ Mn ０．３ Co ０．２ Mg ０．０１ ]O ２ , LiNi ０．８ Co ０．２ O ２ , LiNi ０．８５Co ０．１０ Al ０．０５ O ２ , LiNi ０．８７ Co ０．１０ Al ０．０３ O ２ , LiNi ０．９０ Co ０．０７ Al ０．０３ O ２ , LiNi ０．６ Co ０．３ Al ０．１ O ２、 LiMn １．５ Ni ０．５ O ４ etc.

[0161] For example, when the cation is sodium, the positive electrode material (positive electrode active material) is NaCrO ２ , NaFe ０．５ Co ０．５ O ２ , NaFe ０．４ Mn ０．３ Ni ０．３ O ２ , NaNi ０．５ Ti ０．３ Mn ０．２ O ２ , NaNi １／３ Ti １／３ Mn １／３ O ２ , NaNi ０．３３ Ti ０．３３ Mn ０．１６ Mg ０．１７ O ２ , Na ２／３ Ni １／３ Ti １／６ Mn １／２ O ２ , Na ２／３ Ni １／３ Mn ２／３ O ２ sodium-containing transition metal composite oxides such as those described above, in which a plurality of transition metals such as Co, Mn, and Ni are mixed, sodium-containing transition metal composite oxides in which a part of the transition metal is replaced with a metal other than the transition metal, NaFePO ４ , NaVPO ４ F, Na ３ V ２ (P.O.４ ) ３ , Na ２ Fe ２ (SO ４ ) ３ Polyanion type compounds such as those of the formula Na ａ M ｂ [Fe(CN) ６ ] ｃ (M=Cr, Mn, Fe, Co, Ni, Cu, or Zn, and 0≦a≦2, 0.5≦b≦1.5, 0.5≦c≦1.5), TiO ２ , V ２ O ５ , MoO ３ oxides such as TiS ２ Alternatively, sulfides such as FeS, conductive polymers such as polyacetylene, polyparaphenylene, polyaniline, and polypyrrole, activated carbon, radical-generating polymers, carbon materials, and the like may be used.

[0162] The positive electrode and negative electrode materials may contain, as a conductive material, acetylene black, ketjen black, carbon fiber, or graphite, and as a binder, polytetrafluoroethylene, polyvinylidene fluoride, SBR resin, or the like, and may further contain an electrode sheet formed into a sheet.

[0163] As a separator for preventing contact between the positive electrode and the negative electrode, a nonwoven fabric or porous sheet made of polypropylene, polyethylene, paper, glass fiber, or the like may be used.

[0164] The above elements are assembled into an electrochemical device having a coin-like, cylindrical, rectangular, aluminum laminate sheet, or other shape.

[0165] The present disclosure will be specifically described below using examples, but the present disclosure is not limited to such examples.

[0166] [Examples 1-1 to 1-41, Comparative Examples 1-1 to 1-37] <Preparation of Non-Aqueous Electrolyte> In a glove box with a dew point of −60° C. or less, EC, EMC, and DMC were mixed as (III) in a volume ratio of EC:EMC:DMC=25:50:25. Thereafter, while maintaining the internal temperature at 40° C. or less, LiPF was added as (II) under stirring.６ The non-aqueous electrolyte solution was prepared by adding and dissolving the compound (1-1) as (I) to a concentration of 1.0 mol / L relative to the total amount of the non-aqueous electrolyte solution, and then adding and dissolving the compound (1-1) as (I) to a concentration of 1.0 mass% relative to the total amount of the non-aqueous electrolyte solution, and then adding a predetermined amount of pure water to generate hydrogen fluoride in the non-aqueous electrolyte solution and stirring for 1 hour to prepare the non-aqueous electrolyte solution of Comparative Example 1-1. In addition, as shown in Tables 1 to 5, the type and concentration of (I) were changed, the concentration of hydrogen fluoride was changed by adding water, and the type and concentration of (IV) were changed. The non-aqueous electrolyte solutions of each Example and Comparative Example were prepared in the same manner as the non-aqueous electrolyte solution of Comparative Example 1-1.

[0167] The hydrogen fluoride concentration was measured by titration using a triethylamine / acetone solution 24 hours after the preparation of the non-aqueous electrolyte. In all Examples and Comparative Examples, it was confirmed using a Karl Fischer moisture meter that no water remained in the non-aqueous electrolyte 24 hours after the preparation.

[0168] The compounds used in the examples and comparative examples are shown below. Only the compound numbers are shown in the tables. (1-1): Diglycolic anhydride (1-2): Thiodiacetic anhydride (1-3): Sulfodiacetic anhydride (2-1): Lithium difluorophosphate (2-2): Lithium fluorosulfonate (2-3): Lithium trifluoromethanesulfonate (2-4): Lithium tetrafluoroborate (3-1): Lithium bis(fluorosulfonyl)imide (3-2): Lithium (fluorosulfonyl)(difluorophosphoryl)imide (3-3): Lithium bis(trifluoromethanesulfonyl)imide (3-4): Lithium bis(difluorophosphoryl)imide (4-1): Lithium bis(oxalato)borate (4-2): Lithium tris(oxalato)phosphate (4-3): Lithium difluorobis(oxalato)phosphate (5-1): Trivinylmethylsilane (5-2): Trivinylfluorosilane (5-3): Tetravinylsilane (6-1): 1,3,2-dioxathiolane-2,2-dioxide (7-1): 1,3-propane sultone (7-2): 1-propene 1,3-sultone (8-1): 1,2-ethanedisulfonic anhydride (9-1): methanesulfonic anhydride

[0169] (Preparation of NCM811 positive electrode) LiNi ０．８ Mn ０．１ Co ０．１ O ２ 92.0% by mass of the powder was mixed with 3.5% by mass of polyvinylidene fluoride (hereinafter also referred to as "PVDF") as a binder and 4.5% by mass of acetylene black as a conductive material, and further N-methyl-2-pyrrolidone (hereinafter also referred to as "NMP") was added to the LiNi 0.8 Mn 0.1 Co 0.1 O ２ The paste was applied to both sides of an aluminum foil (A1085), dried, pressed, and punched into a 4 cm × 5 cm piece to obtain a test NCM811 positive electrode.

[0170] (Preparation of Natural Graphite Negative Electrode) 97.0% by mass of natural graphite powder, 2.0% by mass of styrene butadiene rubber (hereinafter also referred to as "SBR") as a binder, 1.0% by mass of sodium carboxymethyl cellulose (hereinafter also referred to as "CMC"), and water were mixed to prepare a negative electrode composite paste. This paste was applied to one side of copper foil, dried, pressed, and then punched out to 4.5 cm x 5.5 cm to obtain a test natural graphite negative electrode.

[0171] (Preparation of silicon-containing graphite negative electrode) 85.0% by mass of artificial graphite powder, 7.0% by mass of nanosilicon, 3.0% by mass of conductive material (HS-100 manufactured by Denka), 2.0% by mass of carbon nanofiber (VGCF manufactured by Showa Denko), 2.0% by mass of SBR, 1.0% by mass of CMC, and water were mixed to prepare a negative electrode composite paste. This paste was applied to one side of copper foil, dried, pressed, and then punched out to 4.5 cm x 5.5 cm to obtain a silicon-containing graphite negative electrode for testing.

[0172] (Preparation of non-aqueous electrolyte batteries listed in Tables 1 to 5) In an argon atmosphere with a dew point of −50° C. or lower, a terminal was welded to the aforementioned NCM811 positive electrode, and then the electrode was sandwiched between two polyethylene separators (5 cm × 6 cm). The outer surface of the separator was further sandwiched between two natural graphite negative electrodes with terminals previously welded, with the negative electrode active material surface facing the positive electrode active material surface. These were then placed in an aluminum laminate bag with an opening on one side, and the non-aqueous electrolyte prepared above was vacuum-injected into the bag. The opening was then heat-sealed to prepare aluminum laminate-type non-aqueous electrolyte batteries of the examples and comparative examples listed in Tables 1 to 5 below.

[0173] (Evaluation of Nonaqueous Electrolyte Battery) - Initial Charge / Discharge - The fabricated nonaqueous electrolyte battery was placed in a thermostatic chamber at 25°C and connected to a charge / discharge device in this state. Current density: 0.38 mA / cm ２ After maintaining 4.2 V for 1 hour, the battery was charged at a current density of 0.38 mA / cm ２ The battery was discharged at 100 V to 2.5 V. This was defined as one charge / discharge cycle, and a total of three charge / discharge cycles were performed to stabilize the battery. The discharge capacity at the third cycle was defined as the initial charge / discharge capacity.

[0174] <Initial resistance> 25℃, 0.38mA / cm after initial charge / discharge ２ The battery was charged to 4.2 V, and the resistance value was measured by impedance measurement.

[0175] <High-temperature storage characteristics> The nonaqueous electrolyte battery after the initial charge and discharge was charged at an upper limit voltage of 4.2 V and a current of 0.38 mA / cm ２ After that, the battery was taken out of the charge / discharge device maintained at 25°C, placed in a thermostatic chamber at 60°C, and stored for 14 days. Thereafter, the battery was placed in a charge / discharge device maintained at 25°C, and charged at 0.38 mA / cm until the discharge cut-off voltage reached 2.5 V. ２ The battery was discharged, and the discharge capacity retention rate after storage at 60°C was calculated using the following formula.

[0176] (Discharge capacity retention rate after storage at 60°C) Discharge capacity retention rate (%) = (discharge capacity after storage at 60°C / initial charge / discharge capacity) × 100

[0177] (Resistance value after storage at 60°C) Next, at 25°C, 0.38 mA / cm ２ The battery was charged to 4.2 V, and the resistance value was measured by impedance measurement.

[0178] In the following Tables 1 to 5, the initial resistance value represents a relative value when Comparative Example 1-1 is set to 100, "E1" represents the discharge capacity retention rate after storage at 60°C (a relative value when Comparative Example 1-1 is set to 100), and "E2" represents the resistance value after storage at 60°C (a relative value when Comparative Example 1-1 is set to 100). The hydrogen fluoride concentration (ppm) is a concentration based on mass.

[0179]

[0180]

[0181]

[0182]

[0183]

[0184] Tables 1 to 4 show that, when compared under the same conditions of type and concentration of (IV), the nonaqueous electrolyte batteries containing the nonaqueous electrolyte solutions of the Examples have lower initial resistance than the nonaqueous electrolyte batteries containing the nonaqueous electrolyte solutions of the Comparative Examples. Furthermore, the nonaqueous electrolyte batteries containing the nonaqueous electrolyte solutions of the Examples have a larger E1 and a smaller E2 than the nonaqueous electrolyte batteries containing the nonaqueous electrolyte solutions of the Comparative Examples. Furthermore, Table 5 shows that a concentration of (I) of 0.01% by mass or more and 5.0% by mass or less is more effective in reducing initial resistance, and that a concentration of 0.1% by mass or more and 1.5% by mass or less results in the lowest initial resistance. Furthermore, the nonaqueous electrolyte batteries containing the nonaqueous electrolyte solutions of the Examples have a larger E1 and a smaller E2 than the nonaqueous electrolyte batteries containing the nonaqueous electrolyte solutions of the Comparative Examples.

[0185] [Examples 2-1 to 2-23, Comparative Examples 2-1 to 2-23] <Preparation of Non-Aqueous Electrolyte> In a glove box with a dew point of −60° C. or less, EC, EMC, and DMC were mixed as (III) in a volume ratio of EC:EMC:DMC=25:50:25. Thereafter, while maintaining the internal temperature at 40° C. or less, LiPF as (II) was added under stirring. ６ The non-aqueous electrolyte solution was dissolved to a concentration of 1.0 mol / L relative to the total amount of the non-aqueous electrolyte, and the compound (1-1) was dissolved as (I) to a concentration of 1.0 wt% relative to the total amount of the non-aqueous electrolyte, and other additives were added and dissolved to concentrations of 5.0 wt% and 1.0 wt% relative to the total amount of the non-aqueous electrolyte, respectively, and then pure water was added to generate hydrogen fluoride in the non-aqueous electrolyte solution and stirred for 1 hour to prepare the non-aqueous electrolyte solution of Comparative Example 2-1. Further, as shown in Tables 6 to 8, changing the type and concentration of (I), changing the concentration of hydrogen fluoride by adding water, except for changing the type and concentration of (IV), the non-aqueous electrolyte solution of each example and comparative example was prepared in the same manner as the non-aqueous electrolyte solution of Comparative Example 2-1.

[0186] (Preparation of non-aqueous electrolyte batteries listed in Tables 6 to 8) In an argon atmosphere with a dew point of −50° C. or less, a terminal was welded to the aforementioned NCM811 positive electrode, and then the electrode was sandwiched between two polyethylene separators (5 cm × 6 cm). The outer surface of the separator was further sandwiched between two silicon-containing graphite negative electrodes with terminals previously welded, with the negative electrode active material surface facing the positive electrode active material surface. These were then placed in an aluminum laminate bag with an opening on one side, and the non-aqueous electrolyte prepared above was vacuum-injected into the bag. The opening was then heat-sealed to prepare aluminum laminate-type non-aqueous electrolyte batteries of the examples and comparative examples listed in Tables 6 to 8 below.

[0187] (Evaluation of Nonaqueous Electrolyte Battery) - Initial Charge / Discharge - The fabricated nonaqueous electrolyte battery was placed in a thermostatic chamber at 25°C and connected to a charge / discharge device in this state. Current density: 0.38 mA / cm ２ After maintaining 4.2 V for 1 hour, the battery was charged at a current density of 0.38 mA / cm ２ This was counted as one charge-discharge cycle, and a total of three charge-discharge cycles were carried out to stabilize the battery.

[0188] <Initial resistance> 25℃, 0.38mA / cm after initial charge / discharge ２ The battery was charged to 4.2 V, and the resistance value was measured by impedance measurement.

[0189] <Cycle characteristic test at 25° C.> A charge / discharge test was carried out at an ambient temperature of 25° C. to evaluate the cycle characteristics. Charging was performed up to 4.2 V and discharging was performed up to 2.5 V, and the current density was 1.9 mA / cm ２ The charge-discharge cycle was repeated at 25°C. The deterioration of the cell was evaluated based on the discharge capacity retention rate after 200 cycles. The discharge capacity retention rate after 200 cycles was calculated using the following formula. The discharge capacity at the first cycle in the cycle characteristic test at an ambient temperature of 25°C was defined as the initial discharge capacity.

[0190] (Discharge capacity retention rate after 200 cycles) Discharge capacity retention rate (%) = (discharge capacity after 200 cycles / initial discharge capacity) x 100

[0191] (Resistance value after 200 cycles) The nonaqueous electrolyte battery after the cycle characteristic test was subjected to a test at 25°C and 0.38 mA / cm２ The battery was charged to 4.2 V, and the resistance value was measured by impedance measurement.

[0192] In the following Tables 6 to 8, the initial resistance value represents a relative value when Comparative Example 2-1 is set to 100, "E3" represents the discharge capacity retention rate after the cycle characteristic test at 25°C (a relative value when Comparative Example 2-1 is set to 100), and "E4" represents the resistance value after the cycle characteristic test at 25°C (a relative value when Comparative Example 2-1 is set to 100). The hydrogen fluoride concentration (ppm) is a concentration based on mass.

[0193]

[0194]

[0195]

[0196] Tables 6 to 8 show that the nonaqueous electrolyte batteries containing the nonaqueous electrolytes of the Examples have lower initial resistance than the nonaqueous electrolyte batteries containing the nonaqueous electrolytes of the Comparative Examples. Furthermore, the nonaqueous electrolyte batteries containing the nonaqueous electrolytes of the Examples have larger E3 and smaller E4 than the nonaqueous electrolyte batteries containing the nonaqueous electrolytes of the Comparative Examples.

[0197] According to the present disclosure, it is possible to provide a nonaqueous electrolyte that can reduce the initial resistance of a nonaqueous electrolyte battery, and a nonaqueous electrolyte battery with low initial resistance.

[0198] Although the present disclosure has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present disclosure. This application is based on a Japanese patent application (Patent Application No. 2023-123775) filed on July 28, 2023, the contents of which are incorporated herein by reference.

Claims

1. A non-aqueous electrolyte solution containing (I) a compound represented by the following general formula (1), (II) a solute, (III) a non-aqueous organic solvent, and hydrogen fluoride, wherein the concentration of the hydrogen fluoride relative to the total amount of the non-aqueous electrolyte solution is 0.1 ppm by mass or more and 180 ppm by mass or less. In general formula (1), R １ ~R ４ each independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, or an aryl group; X represents an oxygen atom, a sulfur atom, or SO ２ Represents a group.

2. The nonaqueous electrolyte according to claim 1, further comprising (IV) at least one compound selected from the group consisting of the following compounds (2) to (9): Compound (2): At least one compound selected from the group consisting of compounds represented by the following general formula (2-1) and compounds represented by the following general formula (2-2). In general formula (2-1), R ２１ and R ２２ are each independently a fluorine atom, or an organic group selected from an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and the organic group may also contain a fluorine atom, an oxygen atom, or an unsaturated bond. Furthermore, general formula (2-1) contains at least one P-F bond. In general formula (2-2), X ２１ is a fluorine atom, or an organic group selected from an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a cycloalkenyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and the organic group may contain at least one fluorine atom, and the organic group may also contain an oxygen atom or an unsaturated bond. In general formula (2-1) and general formula (2-2), M １ ｍ＋ is a proton, a metal cation or an onium cation. m represents the valence of the corresponding cation. Compound (3): at least one compound selected from the group consisting of a compound represented by the following general formula (3-1), a compound represented by the following general formula (3-2) and a compound represented by the following general formula (3-3). In general formulas (3-1) to (3-3), R ３１ ~R ３６ are each independently a fluorine atom or an organic group selected from an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and the organic group may also contain a fluorine atom, an oxygen atom, or an unsaturated bond. ３１ ~X ３３ are each independently a fluorine atom, or an organic group selected from an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a cycloalkenyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyloxy group having 2 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, a cycloalkoxy group having 3 to 10 carbon atoms, a cycloalkenyloxy group having 3 to 10 carbon atoms, and an aryloxy group having 6 to 10 carbon atoms, and the organic group may also contain a fluorine atom, an oxygen atom, or an unsaturated bond. General formula (3-1) contains at least one P-F bond. General formula (3-2) contains at least one of a P-F bond and an S-F bond. General formula (3-3) contains at least one S-F bond. M １ ｍ＋ is a proton, a metal cation or an onium cation. m represents the valence of the corresponding cation. Compound (4): at least one compound selected from the group consisting of compounds represented by the following general formula (4-1) and compounds represented by the following general formula (4-2). In general formula (4-1), W １ represents a boron atom, a phosphorus atom, or a silicon atom, n1 is 0 to 3, n2 is 0 to 4, and p is 0 or 1. ４１ represents an alkylene group having 1 to 10 carbon atoms, a halogenated alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a halogenated arylene group having 6 to 20 carbon atoms (these groups may contain a substituent or a heteroatom in the structure. When n1 is 2 or more, n1 R ４１ may be bonded to each other), R ４２ represents a halogen atom; Y １ and Y ２ each independently represents an oxygen atom or a sulfur atom; Y ３ represents a carbon atom or a sulfur atom. ３ The carbon atom or sulfur atom represented by is bonded with q oxo groups (=O). ３ is 1 when it is a carbon atom, and is 1 or 2 when it is a sulfur atom. ａ＋ represents an alkali metal cation, an alkaline earth metal cation, or an onium cation, a represents the valence of the corresponding cation, and a to d are 1 or 2, and a×b=c×d is satisfied. In general formula (4-2), R ４３ represents an alkylene group having 1 to 10 carbon atoms, a halogenated alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a halogenated arylene group having 6 to 20 carbon atoms (these groups may contain a substituent or a heteroatom in the structure), and r is 0 or 1. Y ４ represents a carbon atom or a sulfur atom. ４ The carbon atom or sulfur atom represented by is bonded with s oxo groups (=O). ４ is 1 when it is a carbon atom, and 1 or 2 when it is a sulfur atom. ２ represents a boron atom or a phosphorus atom, R ４４ represents a halogen atom. n3 represents W ２ When is a boron atom, it is 2, and when is a phosphorus atom, it is 4. Compound (5): A compound represented by the following general formula (5). In general formula (5), R ５１ Each independently represents a group having a carbon-carbon unsaturated bond. ５２ When a plurality of are present, each independently represents a fluorine atom or an alkyl group having 1 to 10 carbon atoms, and the alkyl group may have at least one of a fluorine atom and an oxygen atom. v represents an integer of 2 to 4. Compound (6): A compound represented by the following general formula (6). In general formula (6), R ６１ and R ６２ R each independently represents a hydrogen atom, an alkyl group having 1 to 2 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an aryl group having 6 to 10 carbon atoms which may be substituted with an alkyl group. ６１ and R ６２ Any hydrogen atom in the alkyl group, alkenyl group and aryl group represented by the formula (7-1) may be substituted with a halogen atom. n6 is 0 or 1. Compound (7): At least one compound selected from the group consisting of compounds represented by the following general formula (7-1) and compounds represented by the following general formula (7-2). In general formula (7-1), R ７０ ~R ７３ each independently represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 5 carbon atoms, or a fluoroalkyl group having 1 to 4 carbon atoms. n71 represents an integer of 1 to 3. In general formula (7-2), R ７４ ~R ７９ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a fluoroalkyl group having 1 to 4 carbon atoms. n72 represents an integer of 0 to 2. Compound (8): A compound represented by the following general formula (8). In general formula (8), R ８１ represents an alkylene group having 1 to 6 carbon atoms, an oxygen atom may be contained between a carbon atom-carbon atom bond in the alkylene group, any hydrogen atom in the alkylene group may be substituted with an alkyl group, and any hydrogen atom in the alkylene group and the alkyl group may be substituted with a halogen atom. Compound (9): A compound represented by the following general formula (9). In general formula (9), R ９１ and R ９２ each independently represents an alkyl group having 1 to 6 carbon atoms.

3. The nonaqueous electrolyte according to claim 1, wherein the concentration of hydrogen fluoride relative to the total amount of the nonaqueous electrolyte is 1 ppm by mass or more and 70 ppm by mass or less.

4. The nonaqueous electrolyte according to claim 1, wherein the content of said (I) is 0.01 mass % or more and 10 mass % or less relative to the total amount of said nonaqueous electrolyte.

5. The nonaqueous electrolyte according to claim 1, wherein the content of said (IV) is 0.01 mass % or more and 10 mass % or less relative to the total amount of said nonaqueous electrolyte.

6. The nonaqueous electrolyte according to claim 1, wherein the compound represented by general formula (1) is at least one compound selected from the group consisting of diglycolic anhydride, methyl diglycolic anhydride, dimethyl diglycolic anhydride, ethyl diglycolic anhydride, vinyl diglycolic anhydride, tetrafluoro diglycolic anhydride, allyl diglycolic anhydride, thiodiacetic anhydride, and sulfodiacetic anhydride.

7. The nonaqueous electrolyte according to claim 2, wherein the compound (2) is at least one compound selected from the group consisting of lithium difluorophosphate, lithium fluorosulfonate, and lithium trifluoromethanesulfonate.

8. The nonaqueous electrolyte according to claim 2, wherein the compound (3) is at least one compound selected from the group consisting of bis(fluorosulfonyl)imide lithium, (fluorosulfonyl)(difluorophosphoryl)imide lithium, bis(trifluoromethanesulfonyl)imide lithium, bis(difluorophosphoryl)imide lithium, bis(pentafluoroethanesulfonyl)imide lithium, and (fluorosulfonyl)(trifluoromethanesulfonyl)imide lithium.

9. The nonaqueous electrolyte according to claim 2, wherein the compound (4) is at least one compound selected from the group consisting of lithium tetrafluoroborate, lithium bis(oxalato)borate, lithium difluoro(oxalato)borate, lithium tris(oxalato)phosphate, lithium difluorobis(oxalato)phosphate, lithium tetrafluoro(oxalato)phosphate, lithium difluoro(malonato)borate, lithium tetrafluoro(malonato)phosphate, tetrafluoro(picolinato)phosphate, and difluoro(picolinato)borate.

10. The nonaqueous electrolyte according to claim 2, wherein the compound (5) is at least one compound selected from the group consisting of trivinylmethylsilane, trivinylfluorosilane, and tetravinylsilane.

11. The nonaqueous electrolyte according to claim 2, wherein the compound (6) is at least one compound selected from the group consisting of 1,3,2-dioxathiolane-2,2-dioxide and 1,3,2-dioxathiane-2,2-dioxide.

12. The nonaqueous electrolyte according to claim 2, wherein the compound (8) is at least one compound selected from the group consisting of 1,2-ethanedisulfonic anhydride and 1,3-propanedisulfonic anhydride.

13. The nonaqueous electrolyte according to claim 2, wherein the compound (9) is at least one compound selected from the group consisting of methanesulfonic anhydride and ethanesulfonic anhydride.

14. The above (II) is LiPF ６ , LiSbF ６ , LiAsF ６ , LiClO ４ , LiAlO ２ , LiAlCl ４ At least one selected from the group consisting of LiCl and LiI, or NaPF ６ , NaSbF ６ , NaAsF ６ , NaClO ４ , NaAlO ２ , NaAlCl ４ 2. The nonaqueous electrolyte according to claim 1, wherein the nonaqueous electrolyte is at least one selected from the group consisting of NaCl and NaI.

15. The nonaqueous electrolyte according to claim 1, wherein the (III) contains at least one selected from the group consisting of cyclic esters, chain esters, cyclic ethers, chain ethers, sulfone compounds, sulfoxide compounds, and ionic liquids.

16. The nonaqueous electrolyte according to claim 15, wherein the cyclic ester is a cyclic carbonate, and the cyclic carbonate is at least one selected from the group consisting of ethylene carbonate, propylene carbonate, and fluoroethylene carbonate.

17. The nonaqueous electrolyte according to claim 15, wherein the chain ester is a chain carbonate, and the chain carbonate is at least one selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, and methyl propyl carbonate.

18. A nonaqueous electrolyte battery comprising at least a positive electrode, a negative electrode, a separator, and the nonaqueous electrolyte according to any one of claims 1 to 17.

19. A method for reducing the initial resistance of a nonaqueous electrolyte battery containing a nonaqueous electrolyte, comprising using a nonaqueous electrolyte containing (I) a compound represented by the following general formula (1), (II) a solute, (III) a nonaqueous organic solvent, and hydrogen fluoride as the nonaqueous electrolyte, and setting the concentration of the hydrogen fluoride relative to the total amount of the nonaqueous electrolyte to be 0.1 ppm by mass or more and 180 ppm by mass or less. In general formula (1), R １ ~R ４ each independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, or an aryl group; X represents an oxygen atom, a sulfur atom, or SO ２ Represents a group.

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