Nonaqueous electrolyte, nonaqueous electrolyte battery, method for manufacturing nonaqueous electrolyte battery, and additive composition for nonaqueous electrolyte

Abstract

A nonaqueous electrolyte according to the present invention contains (I) a compound represented by general formula (I), (II) a compound represented by general formula (II), (III) a solute, and (IV) a nonaqueous organic solvent, wherein the content of compound (II) in the nonaqueous electrolyte is 1-200 mass ppm.

Description

Non-aqueous electrolyte, non-aqueous electrolyte battery, method for manufacturing non-aqueous electrolyte battery, and additive composition for non-aqueous electrolyte

[0001] This disclosure relates to a non-aqueous electrolyte, a non-aqueous electrolyte battery, a method for manufacturing a non-aqueous electrolyte battery, and an additive composition for a non-aqueous electrolyte.

[0002] Lithium difluorophosphate (LiPO) is an electrolyte additive for lithium-ion batteries that can improve the capacity retention rate in high-temperature storage tests. ２ F ２ ) and lithium monofluorophosphate (Li ２ PO ３ F) (Patent Document 1), Ethyl lithium monofluorophosphate (LiPO ２ Lithium ethyllithium monofluorophosphate (F(OEt)) (Patent Document 2) and others are known. Furthermore, Patent Document 3 reports that ethyllithium monofluorophosphate is also effective in improving cycle maintenance rate. Lithium difluorophosphate is a representative high-performance additive for lithium-ion battery electrolytes and is widely used worldwide.

[0003] Japanese Patent Publication No. 11-67270, International Publication No. 2016 / 24496, Japanese Patent Publication No. 2017-120780, International Publication No. 2021 / 025107

[0004] The inventors' investigations revealed that while a reduction in battery resistance was observed regardless of whether lithium difluorophosphate, lithium monofluorophosphate, or ethyl lithium monofluorophosphate was used as an additive to the electrolyte, there was still room for further improvement in reducing battery resistance.

[0005] When using an electrolyte containing lithium difluorophosphate, there is an upper limit to the amount that can be added because Al leaches from the positive electrode current collector. Furthermore, since lithium monofluorophosphate and ethyl lithium monofluorophosphate have poor solubility in the electrolyte, it has been difficult to reduce battery resistance by increasing the amount added. Although Patent Document 3 discloses an electrolyte containing lithium difluorophosphate and ethyl lithium monofluorophosphate, there is still room for improvement in reducing battery resistance.

[0006] As a result of further studies, the inventors of the present invention have found that the battery resistance can be reduced by setting the content of lithium ethyl monofluorophosphate to a predetermined amount in an electrolytic solution containing lithium difluorophosphate and lithium ethyl monofluorophosphate, and have completed the present invention. That is, the present invention can be shown as follows.

[0007] [1] A non-aqueous electrolytic solution containing (I) a compound represented by the following general formula (I), (II) a compound represented by the following general formula (II), (III) a solute, and (IV) a non-aqueous organic solvent, wherein the content of the compound (II) with respect to the non-aqueous electrolytic solution is 1 mass ppm or more and 200 mass ppm or less. (In general formula (I), M ＋ represents an alkali metal ion.) (In general formula (II), M ＋ represents an alkali metal ion. R represents an organic group selected from an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, and an aralkyl group.) [2] M in the general formula (I) and the general formula (II) ＋ is a lithium ion or a sodium ion, and the non-aqueous electrolytic solution according to [1]. [3] R in the general formula (II) is a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms, and the non-aqueous electrolytic solution according to [1] or [2]. [4] (III) The solute is LiPF ６ , LiBF ４ , LiSbF ６ , LiAsF ６ , LiClO ４ , LiN(SO ２ F) ２ , LiAlO ２ , LiAlCl ４ , at least one selected from the group consisting of LiCl and LiI, or NaPF ６ , NaBF ４ , NaSbF ６ , NaAsF ６ , NaClO ４ , NaN(SO ２ F) ２ , NaAlO ２ , NaAlCl４[1] to [3] a non-aqueous electrolyte, wherein at least one selected from the group consisting of NaCl and NaI. [5] A non-aqueous electrolyte according to any one of [1] to [4], wherein 100 parts by mass of the non-aqueous electrolyte contains 0.1 parts by mass or more and 1.5 parts by mass or less of the compound (I). [6] A non-aqueous electrolyte according to any one of [1] to [5], wherein the (IV) non-aqueous organic solvent contains at least one selected from the group consisting of cyclic esters, linear esters, cyclic ethers, linear ethers, sulfone compounds, sulfoxide compounds, and ionic liquids. [7] A non-aqueous electrolyte according to [6], wherein the cyclic ester contains a cyclic carbonate. [8] A non-aqueous electrolyte according to [7], wherein the cyclic carbonate contains one or more selected from the group consisting of ethylene carbonate and propylene carbonate. [9] A non-aqueous electrolyte according to [6], wherein the linear ester contains a linear carbonate.

[10] The non-aqueous electrolyte according to [9], wherein the linear carbonate comprises one or more selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, and methyl propyl carbonate.

[11] The non-aqueous electrolyte according to [6], wherein the cyclic ether comprises one or more selected from the group consisting of tetrahydrofuran, 2-methyltetrahydrofuran, furan, tetrahydropyran, 1,3-dioxane, 1,4-dioxane, 1,3-dioxolane, and trioxane.

[12] The linear ether comprises diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, dimethoxymethane, trimethoxymethane, 1,The non-aqueous electrolyte according to [6], comprising one or more selected from the group consisting of 2-dimethoxyethane, diethoxyethane, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether.

[13] Furthermore, cyclohexylbenzene, cyclohexylfluorobenzene, biphenyl, 2-fluorobiphenyl, tert-butylbenzene, tert-amylbenzene, 2-fluorotoluene, fluorobenzene, difluoroanisole, vinylene carbonate, vinylene carbonate oligomers (number average molecular weight in polystyrene terms of 170-5000), vinylethylene carbonate, divinylethylene carbonate, fluoroethylene carbonate, ethynylethylene carbonate, trans-difluoroethylene carbonate, methylpropargyl carbonate, ethylpropargyl carbonate, dipropargyl carbonate, dimethylvinylene carbonate, dimethyl dicarbonate, bis(1,1,1,3,3,3-hexafluoro-1-propyl) carbonate, bis(2,2,2-trifluoroethyl) carbonate, 1,6-diisocyanatohexa N, maleic anhydride, succinic anhydride, 1,4-dioxan-2,6-dione, glutaric anhydride, methanedisulfonic anhydride, 1,2-ethanedisulfonic anhydride, methanesulfonic anhydride, 2-sulfobenzoic anhydride, 1,3-propanedisulfonic anhydride, 1,3-propanesultone, 1,3-propensultone, 1,4-butanesultone, 2,4-butanesultone, 1,3,2-dioxathiolan-2,2-dioxide, 4-pro Pyr-1,3,2-dioxathiolan-2,2-dioxide, 1,3-dithiolan-1,1,3,3-tetraoxide, 1,3-dithian-1,1,3,3-tetraoxide, 1,2-oxathiolan-5-one-2,2-dioxide, methylene methane disulfate, dimethyl methane disulfate, trimethylene methane disulfate, methyl methanesulfonate, methanesulfonyl fluoride, ethensulfonyl fluoride, N,N'-Carbonylbis(N-methylsulfamoylfluoride), difluoro(picolinato)borate, phenyl difluorophosphate, trippropargyl phosphate, tetrafluoro(picolinato)phosphate, (ethoxy)pentafluorocyclotriphosphazene, succinonitrile, methyldifluorovinylsilane, methylfluorodivinylsilane, dimethyldivinylsilane, trivinylmethylsilane, trivinylfluorosilane, tetravinylsilane, tris(trimethylsilyl)borate, tris(trimethylsilyl)phosphate, 1,3-dimethyl-1,3-divinyl-1,3-di(1,1,1,3,3,3-Hexafluoroisopropyl) disiloxane, fluorosulfonate, trifluoromethanesulfonate, pentafluoroethanesulfonate, nonafluorobutanesulfonate, monomethyl sulfate, monoethyl sulfate, bis(trifluoromethanesulfonyl)imide, bis(pentafluoroethanesulfonyl)imide, (trifluoromethanesulfonyl)(nonafluorobutanesulfonyl)imide, (trifluoromethanesulfonyl)(pentafluoroethanesulfonyl)imide, (trifluoromethanesulfonyl)(fluorosulfonyl)imide, (pentafluoroethanesulfonyl)(fluorosulfonyl)imide, (difluorophosphoryl)(fluorosulfonyl)imide, (difluorophosphoryl)(trifluoromethanesulfonyl)imide, bis(difluorophosphoryl) A non-aqueous electrolyte according to any one of [1] to

[12] , comprising one or more selected from the group consisting of mid salt, (fluorosulfonyl)(carbonyloxymethanesulfonate lithium)imide, (fluorosulfonyl)(carbonyldi(2-propenyl)phosphoryl)imide salt, (carbonyldi(propargyl)phosphoryl)imide salt, tetrafluoro(malonato) phosphate, tris(oxalato) phosphate, difluorobis(oxalato) phosphate, tetrafluorooxalato phosphate, bis(oxalato) borate, difluorooxalatoborate, difluoro(malonato) borate, tris(trifluoromethanesulfonyl)methide salt, tris(fluorosulfonyl)methide salt, acrylate salt, methacrylate salt, nitrate, nitrite, hexafluoroisopropanol, and trifluoroethanol.

[14] A non-aqueous electrolyte battery comprising at least a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte according to any one of [1] to

[13] .

[15] A method for manufacturing a non-aqueous electrolyte battery, comprising the step of injecting the non-aqueous electrolyte according to any one of [1] to

[13] .

[16] A non-aqueous electrolyte additive composition containing (I) a compound represented by the following general formula (I) and (II) a compound represented by the following general formula (II), wherein the non-aqueous electrolyte additive composition contains 0.01 parts by mass or more and 2 parts by mass or less of compound (II) in a total of 100 parts by mass of compound (I) and compound (II). (In general formula (I), M ＋ (This represents alkali metal ions.) (In general formula (II), M ＋ represents an alkali metal ion. R represents an organic group selected from alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, aryl groups, and aralkyl groups.)

[17] M in the above general formula (I) and the above general formula (II) ＋ The additive composition for non-aqueous electrolytes according to

[16] , wherein R is a lithium ion or a sodium ion.

[18] The additive composition for non-aqueous electrolytes according to

[16] or

[17] , wherein R in the general formula (II) is a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms.

[0008] According to the present invention, it is possible to provide a non-aqueous electrolyte that can reduce battery resistance, a non-aqueous electrolyte battery containing the non-aqueous electrolyte, a method for manufacturing a non-aqueous electrolyte battery, and an additive composition for non-aqueous electrolytes.

[0009] In this specification, "~" is used to mean that the numbers before and after it are included as the lower and upper limits, respectively.

[0010] The following is a detailed description of this disclosure, but the description of the constituent elements described below is an example of an embodiment of this disclosure and is not limited to these specific contents.

[0011] 1. Non-aqueous electrolyte (first invention) The non-aqueous electrolyte of this disclosure comprises: (I) a compound represented by general formula (I), (II) a compound represented by general formula (II), (III) a solute, and (IV) a non-aqueous organic solvent. Each component will be described below.

[0012] <(I) Compound represented by general formula (I)> The non-aqueous electrolyte of this disclosure contains (I) the compound represented by the following general formula (I) (also referred to as "(I)").

[0013]

[0014] In the general formula (I), M ＋represents an alkali metal ion. The alkali metal ion is not particularly limited and includes lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions, etc., with lithium ions or sodium ions being preferred. (I) As the compound, lithium difluorophosphate and sodium difluorophosphate are preferred.

[0015] (I) Compound is preferably included in 100 parts by mass of the non-aqueous electrolyte of this disclosure in an amount of 0.1 parts by mass or more and 1.5 parts by mass or less, more preferably 0.2 parts by mass or more and 1.3 parts by mass or less, and even more preferably 0.3 parts by mass or more. (I) Compound is preferably included in 100 parts by mass of the non-aqueous electrolyte of this disclosure in an amount of 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, and even more preferably 0.3 parts by mass or more. (I) Compound is preferably included in 100 parts by mass of the non-aqueous electrolyte of this disclosure in an amount of 1.5 parts by mass or less, more preferably 1.3 parts by mass or less, and even more preferably 1.2 parts by mass or less.

[0016] <Regarding the compound represented by general formula (II)> The compound represented by the following general formula (II) (also referred to as "(II)") contained in the non-aqueous electrolyte of this disclosure will be explained below.

[0017]

[0018] In general formula (II), M ＋ represents an alkali metal ion. The alkali metal ion is not particularly limited and includes lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions, etc., with lithium ions or sodium ions being preferred.

[0019] In general formula (II), R represents an organic group selected from alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, aryl groups, and aralkyl groups. Any hydrogen atom of the organic group represented by R may be substituted with a halogen atom. Examples of halogen atoms include fluorine, chlorine, bromine, or iodine atoms, with fluorine being preferred. In this specification, even when a hydrogen atom is substituted with a halogen atom, the terms alkyl group, alkenyl group, alkynyl group, cycloalkyl group, aryl group, and aralkyl group will be used. Furthermore, examples of organic groups for R in general formula (II) include those selected from linear or branched alkyl groups having 1 to 15 carbon atoms, linear or branched alkenyl groups having 2 to 15 carbon atoms, linear or branched alkynyl groups having 2 to 15 carbon atoms, cycloalkyl groups having 3 to 15 carbon atoms, aryl groups having 6 to 15 carbon atoms, and aralkyl groups having 7 to 15 carbon atoms.

[0020] Examples of linear alkyl groups having 1 to 15 carbon atoms or branched alkyl groups having 3 to 15 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, s-butyl group, t-butyl group, n-pentyl group, n-hexyl group, and n-dodecyl group. C1 to 10 alkyl groups are preferred, and methyl group, ethyl group, n-propyl group, or i-propyl group are preferred.

[0021] Examples of linear alkenyl groups having 2 to 15 carbon atoms or branched alkenyl groups having 3 to 15 carbon atoms include vinyl group, 1-propenyl group, 2-propenyl group (allyl group), isopropenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 1-hexenyl group, 2-hexenyl group, 3-hexenyl group, 1-heptenyl group, 2-heptenyl group, 5-heptenyl group, 1-octenyl group, 3-octenyl group, 5-octenyl group, and dodecenyl group.

[0022] Examples of linear alkynyl groups having 2 to 15 carbon atoms or branched alkynyl groups having 3 to 15 carbon atoms include acetylenyl group, 1-propynyl group, 2-propynyl group, 1-butynyl group, 2-butynyl group, 3-butynyl group, 1-pentynyl group, 2-pentynyl group, 3-pentynyl group, 1-hexynyl group, 2-hexynyl group, 3-hexynyl group, 1-heptynyl group, 2-heptynyl group, 5-heptynyl group, 1-octinyl group, 3-octinyl group, and 5-octinyl group.

[0023] Examples of cycloalkyl groups having 3 to 15 carbon atoms include cyclopropyl group, cyclobutyl group, cyclopentyl group, methylcyclopentyl group, cyclohexyl group, methylcyclohexyl group, cyclooctyl group, and methylcyclooctyl group.

[0024] Examples of aryl groups having 6 to 15 carbon atoms include phenyl, tolyl, naphthyl, and anthracenyl groups. Examples of aralkyl groups having 7 to 15 carbon atoms include benzyl, phenethyl, and phenylethyl groups.

[0025] In this disclosure, R in general formula (II) is preferably a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Examples of compound (II) include lithium ethyl monofluorophosphate and sodium ethyl monofluorophosphate.

[0026] The content of compound (II) can be 1 ppm by mass or more and 200 ppm by mass or less, preferably 2 ppm by mass or more and 150 ppm by mass or less, more preferably 3 ppm by mass or more and 100 ppm by mass or less, even more preferably 4 ppm by mass or more and 95 ppm by mass or less, and particularly preferably 5 ppm by mass or more and 90 ppm by mass or less, relative to the non-aqueous electrolyte of the present disclosure. The content of compound (II) can be 1 ppm by mass or more, preferably 2 ppm by mass or more, more preferably 3 ppm by mass or more, even more preferably 4 ppm by mass or more, and particularly preferably 5 ppm by mass or more, relative to the non-aqueous electrolyte of the present disclosure. The content of compound (II) can be 200 ppm by mass or less, preferably 150 ppm by mass or less, more preferably 100 ppm by mass or less, even more preferably 95 ppm by mass or less, and particularly preferably 90 ppm by mass or less, relative to the non-aqueous electrolyte of the present disclosure. The non-aqueous electrolyte of this disclosure, by containing compound (II) together with compound (I) in the above-mentioned amounts, exhibits excellent cycle characteristics in high-temperature environments and can reduce battery resistance after cycling.

[0027] Compound (II) decomposes more easily during charging than compound (I), and can form an SEI (Solid Electrolyte Interphase) film at the electrode electrolyte interface from the beginning. As disclosed herein, by including a predetermined amount of compound (II) together with compound (I) in the non-aqueous electrolyte, a good SEI film can be formed at the electrode electrolyte interface from the beginning, and then, during the cycle, compound (I) decomposes to form an SEI film and repairs the film. In other words, compound (II) and compound (I) contribute to the formation of the SEI film at different times, and by including a predetermined amount of compound (II) together with compound (I), the battery resistance can be reduced from the beginning to after the cycle. On the other hand, if the amount of compound (II) added exceeds the above range, compound (II) suppresses the formation of the SEI film by compound (I) during the cycle, so the battery resistance after the cycle increases relatively.

[0028] Furthermore, the non-aqueous electrolyte of this disclosure may contain, per 100 parts by mass of compound (I), compound (II) in an amount preferably 0.01 parts by mass or more and 2 parts by mass or less, more preferably 0.02 parts by mass or more and 1.5 parts by mass or less, even more preferably 0.03 parts by mass or more and 1.0 part by mass or less, even more preferably 0.04 parts by mass or more and 0.95 parts by mass or less, and particularly preferably 0.05 parts by mass or more. The non-aqueous electrolyte of this disclosure may contain, per 100 parts by mass of compound (I), compound (II) in an amount preferably 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, even more preferably 0.03 parts by mass or more, even more preferably 0.04 parts by mass or more, and particularly preferably 0.05 parts by mass or more. The non-aqueous electrolyte of this disclosure may contain compound (II) in an amount of preferably 2 parts by mass or less, more preferably 1.5 parts by mass or less, even more preferably 1.0 part by mass or less, even more preferably 0.95 parts by mass or less, and particularly preferably 0.90 parts by mass or less, per 100 parts by mass of compound (I). By containing compound (II) in the above amounts relative to compound (I), the battery resistance of the non-aqueous electrolyte of this disclosure can be further reduced.

[0029] Furthermore, the non-aqueous electrolyte of this disclosure may contain compound (I) and compound (II) in the following amounts.

[0030] The non-aqueous electrolyte of this disclosure may contain compound (II) in an amount of 1 ppm by mass or more and 200 ppm by mass or less, and may contain 0.01 parts by mass or more and 2 parts by mass or less of compound (II) per 100 parts by mass of compound (I). Alternatively, the non-aqueous electrolyte of this disclosure may contain compound (II) in an amount of 2 ppm by mass or more and 150 ppm by mass or less, and may contain 0.02 parts by mass or more and 1.5 parts by mass or less of compound (II) per 100 parts by mass of compound (I). Alternatively, the non-aqueous electrolyte of this disclosure may contain compound (II) in an amount of 3 ppm by mass or more and 100 ppm by mass or less, and may contain 0.03 parts by mass or more and 1.0 part by mass or less of compound (II) per 100 parts by mass of compound (I). Furthermore, the non-aqueous electrolyte of this disclosure may contain compound (II) in an amount of 4 ppm by mass or more and 95 ppm by mass or less, and may contain 0.04 parts by mass or more and 0.95 parts by mass or less of compound (II) per 100 parts by mass of compound (I). Furthermore, the non-aqueous electrolyte of this disclosure may contain compound (II) in an amount of 5 ppm by mass or more and 90 ppm by mass or less, and may contain 0.05 parts by mass or more and 0.90 parts by mass or less of compound (II) per 100 parts by mass of compound (I).

[0031] Furthermore, the non-aqueous electrolyte of this disclosure may contain compound (II) in an amount of 1 ppm by mass or more and 200 ppm by mass or less, and compound (I) may be contained in an amount of 0.1 parts by mass or more and 1.5 parts by mass or less per 100 parts by mass of the non-aqueous electrolyte. Furthermore, the non-aqueous electrolyte of this disclosure may contain compound (II) in an amount of 2 ppm by mass or more and 150 ppm by mass or less, and compound (I) may be contained in an amount of 0.2 parts by mass or more and 1.3 parts by mass or less per 100 parts by mass of the non-aqueous electrolyte. Furthermore, the non-aqueous electrolyte of this disclosure may contain compound (II) in an amount of 3 ppm by mass or more and 100 ppm by mass or less, and compound (I) may be contained in an amount of 0.3 parts by mass or more and 1.2 parts by mass or less per 100 parts by mass of the non-aqueous electrolyte. Furthermore, the non-aqueous electrolyte of this disclosure may contain compound (II) in an amount of 4 ppm by mass or more and 95 ppm by mass or less, and compound (I) in an amount of 0.3 parts by mass or more and 1.2 parts by mass or less per 100 parts by mass of the non-aqueous electrolyte. Furthermore, the non-aqueous electrolyte of this disclosure may contain compound (II) in an amount of 5 ppm by mass or more and 90 ppm by mass or less, and compound (I) in an amount of 0.3 parts by mass or more and 1.2 parts by mass or less per 100 parts by mass of the non-aqueous electrolyte.

[0032] Furthermore, the non-aqueous electrolyte of this disclosure has a content of compound (II) of 1 ppm by mass or more and 200 ppm by mass or less relative to the non-aqueous electrolyte, and contains 0.01 parts by mass or more and 2 parts by mass or less of compound (II) per 100 parts by mass of compound (I), and compound (I) is one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate. Furthermore, the non-aqueous electrolyte of this disclosure has a content of compound (II) of 2 ppm by mass or more and 150 ppm by mass or less relative to the non-aqueous electrolyte, and contains 0.02 parts by mass or more and 1.5 parts by mass or less of compound (II) per 100 parts by mass of compound (I), and compound (I) is one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate. Furthermore, the non-aqueous electrolyte of this disclosure has a content of compound (II) of 3 ppm by mass or more and 100 ppm by mass or less relative to the non-aqueous electrolyte, and contains 0.03 parts by mass or more and 1.0 part by mass or less of compound (II) per 100 parts by mass of compound (I), and compound (I) is one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate. Furthermore, the non-aqueous electrolyte of this disclosure has a content of compound (II) of 4 ppm by mass or more and 95 ppm by mass or less relative to the non-aqueous electrolyte, and contains 0.04 parts by mass or more and 0.95 parts by mass or less of compound (II) per 100 parts by mass of compound (I), and compound (I) is one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate.Furthermore, the non-aqueous electrolyte of this disclosure has a content of compound (II) of 5 ppm by mass or more and 90 ppm by mass or less relative to the non-aqueous electrolyte, and contains 0.05 parts by mass or more and 0.90 parts by mass or less of compound (II) per 100 parts by mass of compound (I), and compound (I) is one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate.

[0033] Furthermore, the non-aqueous electrolyte of this disclosure has a content of compound (II) of 1 ppm by mass or more and 200 ppm by mass or less relative to the non-aqueous electrolyte, and contains 0.1 parts by mass or more and 1.5 parts by mass or less of compound (I) in 100 parts by mass of the non-aqueous electrolyte, and compound (I) is one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate. Furthermore, the non-aqueous electrolyte of this disclosure has a content of compound (II) of 2 ppm by mass or more and 150 ppm by mass or less relative to the non-aqueous electrolyte, and contains 0.2 parts by mass or more and 1.3 parts by mass or less of compound (I) in 100 parts by mass of the non-aqueous electrolyte, and compound (I) is one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate. Furthermore, the non-aqueous electrolyte of this disclosure has a content of compound (II) of 3 ppm by mass or more and 100 ppm by mass or less relative to the non-aqueous electrolyte, and contains 0.3 parts by mass or more and 1.2 parts by mass or less of compound (I) in 100 parts by mass of the non-aqueous electrolyte, and compound (I) is one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate. Furthermore, the non-aqueous electrolyte of this disclosure has a content of compound (II) of 4 ppm by mass or more and 95 ppm by mass or less relative to the non-aqueous electrolyte, and contains compound (I) in an amount of 0.3 parts by mass or more and 1.2 parts by mass or less per 100 parts by mass of the non-aqueous electrolyte, and compound (I) is one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate.Furthermore, the non-aqueous electrolyte of this disclosure has a content of compound (II) of 5 ppm by mass or more and 90 ppm by mass or less relative to the non-aqueous electrolyte, and contains 0.3 parts by mass or more and 1.2 parts by mass or less of compound (I) in 100 parts by mass of the non-aqueous electrolyte, and compound (I) is one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate.

[0034] <Regarding (III) Solute> The (III) solute (also referred to as "(III)") contained in the non-aqueous electrolyte of this disclosure will be described below. The (III) solute can be any type of solute that has been conventionally used in the field of such non-aqueous electrolytes, without any particular limitations. Such a solute is preferably an ionic salt consisting of any pair of cation and anion, and any type of solute can be used without any particular limitations, as long as it exists in an ionic state as a cation and anion in a non-aqueous organic solvent.

[0035] The solute is preferably an ionic salt consisting of a pair of one or more cations selected from the group consisting of alkali metal ions such as lithium ions and sodium ions, alkaline earth metal ions, and quaternary ammonium, and one or more anions selected from the group consisting of hexafluorophosphate anion, tetrafluoroborate anion, hexafluoroantimonate anion, hexafluoroarsenate anion, perchlorate anion, bis(fluorosulfonyl)imide anion, aluminate anion, tetrachloroaluminate anion, chloride ion, and iodide ion.

[0036] Specifically, LiPF ６ LiBF ４ LiSbF ６ LiAsF ６ LiClO ４ , LiN (SO ２ F) ２ LiAlO ２ LiAlCl４ , at least one selected from the group consisting of LiCl and LiI, or NaPF ６ NaBF ４ NaSbF ６ NaAsF ６ NaClO ４ NaN(SO ２ F) ２ NaAlO ２ NaAlCl ４ At least one selected from the group consisting of NaCl and NaI can be preferably listed.

[0037] In particular, considering the energy density, output characteristics, and lifespan of the non-aqueous electrolyte battery, it is preferable that the cation be one or more selected from the group consisting of lithium ions, sodium ions, potassium ions, magnesium ions, and quaternary ammonium cations, and that the anion be one or more selected from the group consisting of hexafluorophosphate anions, tetrafluoroborate anions, and bis(fluorosulfonyl)imide anions.

[0038] The non-aqueous electrolyte of this disclosure may be (III) used as a single compound alone, or it may be used as a mixture of two or more compounds in any combination and ratio depending on the application.

[0039] There are no particular restrictions on the concentration of (III) relative to the total amount of non-aqueous electrolyte. For example, the lower limit of the concentration of (III) may be 0.5 mol / L or higher, 0.7 mol / L or higher, or 0.9 mol / L or higher. Also, the upper limit of the concentration of (III) relative to the total amount of non-aqueous electrolyte may be 5 mol / L or lower, 4 mol / L or lower, or 2 mol / L or lower. A concentration of (III) of 0.5 mol / L or higher relative to the total amount of non-aqueous electrolyte is preferable because it is less likely to decrease ionic conductivity, and thus less likely to decrease the cycle characteristics and output characteristics of the non-aqueous electrolyte battery. On the other hand, a concentration of (III) of 5 mol / L or lower relative to the total amount of non-aqueous electrolyte is preferable because it is less likely to increase the viscosity of the non-aqueous electrolyte, and thus less likely to decrease ionic conductivity. When two or more types of (III) are used, it is preferable that the total concentration of those solutes is within the above range.

[0040] The temperature at which (III) is dissolved in (IV) a non-aqueous organic solvent is not particularly limited, but may be -20 to 80°C or 0 to 60°C. Furthermore, the cation of the solute is more preferably lithium ions when used in lithium-ion battery applications, and more preferably sodium ions when used in sodium-ion battery applications.

[0041] <Regarding (IV) Non-Aqueous Organic Solvents> The (IV) non-aqueous organic solvent (also referred to as "(IV)") contained in the non-aqueous electrolyte of this disclosure will be described below. The type of (IV) non-aqueous organic solvent is not particularly limited, and any non-aqueous organic solvent can be used. Such non-aqueous organic solvents preferably contain at least one selected from the group consisting of cyclic esters, linear esters, cyclic ethers, linear ethers, sulfone compounds, sulfoxide compounds, amide compounds, nitrile compounds, and ionic liquids, and more preferably contain at least one selected from the group consisting of cyclic esters, linear esters, cyclic ethers, linear ethers, sulfone compounds, sulfoxide compounds, and ionic liquids. Note that cyclic carbonates are a sub-concept of cyclic esters, and linear carbonates are a sub-concept of linear esters.

[0042] (IV) Specific examples of non-aqueous organic solvents include the following: Cyclic esters include cyclic carbonates such as propylene carbonate (hereinafter sometimes referred to as "PC"), ethylene carbonate (hereinafter sometimes referred to as "EC"), and butylene carbonate, as well as γ-butyrolactone and γ-valerolactone. Chain-like esters include 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"), methyl propyl carbonate, ethyl propyl carbonate, methyl butyl carbonate, 2,2,2-trifluoroethyl methyl carbonate, 2,2,2-trifluoroethyl ethyl carbonate, and 2,2,2-trifluoroethyl propyl carbonate. Examples of cyclic ethers include carbonates such as 1,1,1,3,3,3-hexafluoro-1-propylmethyl carbonate, 1,1,1,3,3,3-hexafluoro-1-propylethyl carbonate, and 1,1,1,3,3,3-hexafluoro-1-propylpropyl carbonate, as well as methyl acetate, ethyl acetate, methyl propionate, ethyl propionate (hereinafter sometimes referred to as "EP"), methyl 2-fluoropropionate, and ethyl 2-fluoropropionate. Examples of cyclic ethers include tetrahydrofuran, 2-methyltetrahydrofuran, furan, tetrahydropyran, 1,3-dioxane, 1,4-dioxane, 1,3-dioxolane, and trioxane.

[0043] Examples of linear ethers include diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, dimethoxymethane, trimethoxymethane, 1,2-dimethoxyethane, diethoxyethane, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether. Other examples include sulfone compounds such as dimethyl sulfoxide and sulfolane, sulfoxide compounds, N,N-dimethylformamide, acetonitrile, and propionitrile. Ionic liquids can also be used.

[0044] The cyclic ester may contain a cyclic carbonate, and the cyclic carbonate may contain at least one selected from the group consisting of ethylene carbonate and propylene carbonate.

[0045] The linear ester may contain a linear carbonate, and the linear carbonate may contain at least one selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, and methyl propyl carbonate.

[0046] The cyclic ether may contain one or more selected from the group consisting of tetrahydrofuran, 2-methyltetrahydrofuran, furan, tetrahydropyran, 1,3-dioxane, 1,4-dioxane, 1,3-dioxolane, and trioxane.

[0047] The chain-like ether may contain one or more selected from the group consisting of diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, dimethoxymethane, trimethoxymethane, 1,2-dimethoxyethane, diethoxyethane, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether.

[0048] The non-aqueous electrolyte of this disclosure may use one compound alone as (IV), or two or more compounds mixed in any combination and ratio according to the application. Among these, it is particularly preferable to include at least one selected from the group consisting of PC, EC, DEC, DMC, and EMC, from the viewpoint of electrochemical stability with respect to oxidation and reduction and chemical stability with respect to heat and reaction with the solute.

[0049] Furthermore, it is preferable to include, for example, one or more cyclic carbonates with high dielectric constants and one or more chain carbonates or chain esters with low liquid viscosity as the non-aqueous organic solvent, because this increases the ionic conductivity of the electrolyte. Specifically, the following combinations are more preferable. (1) Combination of EC and EMC, (2) Combination of EC and DEC, (3) Combination of EC, DMC and EMC, (4) Combination of EC, DEC and EMC, (5) Combination of EC, EMC and EP, (6) Combination of PC and DEC, (7) Combination of PC and EMC, (8) Combination of PC and EP, (9) Combination of PC, DMC and EMC, (10) Combination of PC, DEC and EMC, (11) Combination of PC, DEC and EP, (12) Combination of PC, EC and EMC, (13) Combination of PC, EC, DMC and EMC, (14) Combination of PC, EC, DEC and EMC, (15) Combination of PC, EC, EMC and EP

[0050] The concentration of the non-aqueous organic solvent in this disclosure is not particularly limited as long as it functions as a non-aqueous organic solvent, but may be, for example, 40 to 99% by mass, preferably 50 to 95% by mass, and particularly preferably 70 to 93% by mass, based on the total amount (100% by mass) of the non-aqueous electrolyte. The concentration of the non-aqueous organic solvent in this disclosure may be, for example, 40% by mass or more, preferably 50% by mass or more, and particularly preferably 70% by mass or more, based on the total amount (100% by mass) of the non-aqueous electrolyte. The concentration of the non-aqueous organic solvent in this disclosure may be, for example, 99% by mass or less, preferably 95% by mass or less, and particularly preferably 93% by mass or less, based on the total amount (100% by mass) of the non-aqueous electrolyte.

[0051] The content of the cyclic carbonate is not particularly limited and is arbitrary as long as it does not significantly impair the effects of this disclosure. However, when using one type alone, the content may be 3% by volume or more, and more preferably 5% by volume or more, in 100% by volume of the non-aqueous organic solvent. By setting it within this range, a decrease in electrical conductivity due to a decrease in the dielectric constant of the non-aqueous electrolyte is avoided, and it becomes easier to achieve good high-current discharge characteristics, stability to the negative electrode, and cycle characteristics of the non-aqueous electrolyte battery. Alternatively, it may be 90% by volume or less, preferably 85% by volume or less, and more preferably 80% by volume or less. By setting it within this range, the viscosity of the non-aqueous electrolyte is set within an appropriate range, a decrease in ionic conductivity is suppressed, and consequently it becomes easier to achieve good load characteristics of the non-aqueous electrolyte battery.

[0052] Furthermore, cyclic carbonates can be used in any combination of two or more types. One preferred combination is 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. Moreover, the amount of propylene carbonate in the total non-aqueous organic solvent is not particularly limited and is arbitrary as long as it does not significantly impair the effects of this disclosure, but it may be 1% by volume or more, preferably 2% by volume or more, more preferably 3% by volume or more, also 30% by volume or less, preferably 25% by volume or less, and more preferably 20% by volume or less. Including propylene carbonate within this range is preferable because, for example, when combining ethylene carbonate with dialkyl carbonates, the low-temperature characteristics are further improved while maintaining the characteristics of the combination of ethylene carbonate and dialkyl carbonates.

[0053] The chain-like ester may be used alone, or two or more may be used in any combination and ratio. The content of the chain-like ester is not particularly limited, but may be 15% by volume or more, preferably 20% by volume or more, more preferably 25% by volume or more, or 90% by volume or less, preferably 85% by volume or less, and more preferably 80% by volume or less, based on 100% by volume of the non-aqueous organic solvent. By setting the content of the chain-like ester within the above range, the viscosity of the non-aqueous electrolyte can be set to an appropriate range, the decrease in ionic conductivity can be suppressed, and consequently, the input / output characteristics and charge / discharge rate characteristics of the non-aqueous electrolyte battery can be set to a favorable range. In addition, a decrease in electrical conductivity due to a decrease in the dielectric constant of the non-aqueous electrolyte can be avoided, and the input / output characteristics and charge / discharge rate characteristics of the non-aqueous electrolyte battery can be set to a favorable range. Furthermore, by combining a specific chain-like ester with ethylene carbonate in a specific content, the battery performance can be significantly improved.

[0054] For example, when dimethyl carbonate, ethyl methyl carbonate, or a mixture of dimethyl carbonate and ethyl methyl carbonate is selected as a specific chain ester, the content of ethylene carbonate is not particularly limited and is arbitrary as long as it does not significantly impair the effects of this disclosure, but it may be 5% by volume or more, preferably 10% by volume or more, also 45% by volume or less, and preferably 40% by volume or less. The content of dimethyl carbonate may be 20% by volume or more, preferably 30% by volume or more, also 50% by volume or less, and 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, also 50% by volume or less, and preferably 45% by volume or less. By setting the content within the above ranges, the low-temperature deposition temperature of the electrolyte is reduced, the viscosity of the non-aqueous electrolyte is also reduced, the ionic conductivity is improved, and it becomes easier to obtain high input and output even at low temperatures.

[0055] The content of the chain ether is not particularly limited and is arbitrary as long as it does not significantly impair the effects of this 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, per 100% by volume of non-aqueous organic solvent. If the content of the chain ether is within the above range, for example, in the case of a lithium-ion battery in which the cation is mainly lithium, it is easy to ensure the effect of improving ionic conductivity due to the improved degree of lithium ion dissociation of the chain ether and the decrease in viscosity. Furthermore, when the negative electrode active material is a carbonaceous material, the phenomenon of co-insertion of the chain ether together with lithium ions can be suppressed, making it easier to set the input / output characteristics and charge / discharge rate characteristics within an appropriate range.

[0056] The content of the sulfone compound is not particularly limited and is arbitrary as long as it does not significantly impair the effects of the present disclosure. However, it may be 0.3% by volume or more, preferably 0.5% by volume or more, more preferably 1% by volume or more, or 40% by volume or less, preferably 35% by volume or less, and more preferably 30% by volume or less, based on 100% by volume of the non-aqueous organic solvent. If the content of the sulfone compound is within the above range, it is easier to obtain effects that improve durability such as cycle characteristics and storage characteristics, and it is also possible to set the viscosity of the non-aqueous electrolyte within an appropriate range, avoid a decrease in electrical conductivity, and make it easier to set the input / output characteristics and charge / discharge rate characteristics of the non-aqueous electrolyte battery within an appropriate range.

[0057] <About Additives> The non-aqueous electrolyte of this disclosure may contain additives in addition to the components described above. Examples of additives include aromatic compounds such as cyclohexylbenzene, cyclohexylfluorobenzene, biphenyl, 2-fluorobiphenyl, tert-butylbenzene, tert-amylbenzene, 2-fluorotoluene, fluorobenzene, and difluoroanisole; vinylene carbonate (hereinafter sometimes referred to as "VC"); oligomers of vinylene carbonate (number average molecular weight in polystyrene terms of 170 to 5000); vinylethylene carbonate; divinylethylene carbonate; and fluoroethylene carbonate. Carbonate compounds such as ethylpropagyl carbonate (hereinafter sometimes referred to as "FEC"), ethynylethylene carbonate, trans-difluoroethylene carbonate, methylpropargyl carbonate, ethylpropargyl carbonate, dipropargyl carbonate, dimethylvinylene carbonate, dimethyl dicarbonate, bis(1,1,1,3,3,3-hexafluoro-1-propyl) carbonate, bis(2,2,2-trifluoroethyl) carbonate, isocyanate compounds such as 1,6-diisocyanatohexane, and anhydrous malley Organic acid anhydrides such as nic acid, succinic anhydride, 1,4-dioxane-2,6-dione, glutaric acid anhydride, methanedisulfonic acid anhydride, 1,2-ethanedisulfonic acid anhydride, methanesulfonic acid anhydride, 2-sulfobenzoic acid anhydride, 1,3-propanedisulfonic acid anhydride, 1,3-propanesultone, 1,3-propensultone, 1,4-butanesultone, 2,4-butanesultone, 1,3,2-dioxathiolan-2,2-dioxide, 4-propyl-1,3,2-dioxathiolan-2,2-dioxide, 1,3-dithiolan-1, Sulfonic acid ester compounds such as 1,3,3-tetraoxide, 1,3-dithian-1,1,3,3-tetraoxide, 1,2-oxathiolan-5-one-2,2-dioxide, methylene methane disulfonate, dimethyl methane disulfonate, trimethylene methane disulfonate, methyl methanesulfonate, methanesulfonyl fluoride, ethensulfonyl fluoride, N,N'-carbonylbis(N-methylsulfamoyl fluoride), sulfonyl compounds, and boric acid ester compounds such as difluoro(picolinato)borate.Phosphate ester compounds such as phenyl difluorophosphate, trippropargyl phosphate, and tetrafluoro(picolinat) phosphate; phosphazene compounds such as (ethoxy)pentafluorocyclotriphosphazene; nitrile compounds such as succinonitrile; methyldifluorovinylsilane, methylfluorodivinylsilane, dimethyldivinylsilane, trivinylmethylsilane, trivinylfluorosilane, tetravinylsilane, tris(trimethylsilyl)borate, and tris(trimethylsilyl)phosphate. Siloxane compounds such as 1,3-dimethyl-1,3-divinyl-1,3-di(1,1,1,3,3,3-hexafluoroisopropyl)disiloxane, sulfonates such as fluorosulfonates, trifluoromethanesulfonates, pentafluoroethanesulfonates, and nonafluorobutanesulfonates (preferably fluorosulfonates and trifluoromethanesulfonates), monoalkyl sulfates such as monomethyl sulfate and monoethyl sulfate, bis(trifluoromethanesulfonyl)imide salts, and bis(pe (Trifluoroethanesulfonyl)imide salt, (trifluoromethanesulfonyl)(nonafluorobutanesulfonyl)imide salt, (trifluoromethanesulfonyl)(pentafluoroethanesulfonyl)imide salt, (trifluoromethanesulfonyl)(fluorosulfonyl)imide salt, (pentafluoroethanesulfonyl)(fluorosulfonyl)imide salt, (difluorophosphoryl)(fluorosulfonyl)imide salt, (difluorophosphoryl)(trifluoromethanesulfonyl)imide salt, bis(difluorophosphoryl (Lu)imide salt, (fluorosulfonyl) (carbonyloxymethanesulfonate lithium)imide salt, (fluorosulfonyl) (carbonyldi(2-propenyl)phosphoryl)imide salt, (carbonyldi(propargyl)phosphoryl)imide salt (preferably bis(trifluoromethanesulfonyl)imide salt, (trifluoromethanesulfonyl) (fluorosulfonyl)imide salt, (difluorophosphoryl) (fluorosulfonyl)imide salt, (difluorophosphoryl) (trifluoromethanesulfonyl)imide salt,Examples include imide salts such as bis(difluorophosphoryl)imide salts, or imide compounds in which a hydrogen atom is bonded to a nitrogen atom instead of a cation in the above imide salts), phosphates such as tetrafluoro(malonato) phosphate, tris(oxalato) phosphate, difluorobis(oxalato) phosphate, and tetrafluorooxalato phosphate, borates such as bis(oxalato) borate, difluorooxalatoborate, and difluoro(malonato)borate, methide salts such as tris(trifluoromethanesulfonyl)methide salt and tris(fluorosulfonyl)methide salt, carboxylates such as acrylates and methacrylates, inorganic salts such as nitrates and nitrites, and fluorine-containing alcohols such as hexafluoroisopropanol and trifluoroethanol. The cation in the above salts may be an alkali metal ion, an alkaline earth metal ion, or a quaternary ammonium compound.

[0058] The above additives can be used individually or in combination of two or more. The above additives may be added, for example, in any ratio commonly used in this art. By including the above additives in the non-aqueous electrolyte of this disclosure, at least one of the following effects may be enhanced: overcharge prevention effect, negative electrode film formation effect, and positive electrode protection effect.

[0059] If the non-aqueous electrolyte of this disclosure contains the above-mentioned additives, the content of the additives may be 0.01% by mass or more and 10% by mass or less based on the total amount of the non-aqueous electrolyte. Of the above-mentioned additives, the content of fluoroethylene carbonate may be 0.01% by mass or more and 55% by mass or less based on the total amount of the non-aqueous electrolyte.

[0060] <Regarding other components that may be included> The non-aqueous electrolyte of this disclosure is composed of the above components as basic components, but the non-aqueous electrolyte of this disclosure may contain the components described below (hereinafter also referred to as "other components that may be included" or "other components") in any combination and ratio, as long as the gist of this disclosure is not impaired. As other components, for example, other additives that are commonly used in this art may be added in any ratio.

[0061] Furthermore, the non-aqueous electrolyte of this disclosure may further contain the following compounds in order to improve the cycle capacity maintenance rate and gas generation during cycle testing.

[0062]

[0063] By including the above-mentioned other components in the non-aqueous electrolyte of this disclosure, at least one of the following effects may be enhanced: overcharge prevention effect, negative electrode film formation effect, and positive electrode protection effect.

[0064] Furthermore, as is the case when used in non-aqueous electrolyte batteries called lithium polymer batteries, the electrolyte for non-aqueous electrolyte batteries can be pseudo-solidified using a gelling agent or crosslinking polymer. Examples of the polymers mentioned above include polymers having polyethylene oxide as the main chain or side chain, homopolymers or copolymers of polyvinylidene fluoride, methacrylate polymers, and polyacrylonitrile.

[0065] If the non-aqueous electrolyte of this disclosure contains other components, the content of the other components may be 0.01% by mass or more and 10% by mass or less with respect to the total amount of the non-aqueous electrolyte.

[0066] Furthermore, the content of bis(trifluoromethanesulfonyl)imide salts, trifluoromethanesulfonates, and nonafluorobutanesulfonates relative to the total amount of the non-aqueous electrolyte may be 0.01% by mass or more and 20% by mass or less.

[0067] Furthermore, the content of bis(1,1,1,3,3,3-hexafluoro-1-propyl) carbonate and bis(2,2,2-trifluoroethyl) carbonate relative to the total amount of the non-aqueous electrolyte may be 0.1% by mass or more and 70% by mass or less.

[0068] Furthermore, if the above-mentioned other components are ionic salts, the cations are more preferably lithium ions when used in lithium-ion battery applications, and more preferably sodium ions when used in sodium-ion battery applications.

[0069] The non-aqueous electrolyte of this disclosure may use multiple types of salt compounds of the above-mentioned solutes (such as lithium salts and sodium salts) and other components, depending on the required characteristics, so that the total number of alkali metal salts is four or more. Alternatively, the total number of alkali metal salts may be five or more.

[0070] The non-aqueous electrolyte of this disclosure is suitably used in non-aqueous electrolyte batteries (preferably non-aqueous electrolyte secondary batteries).

[0071] 2. Non-aqueous electrolyte (Second Invention) The non-aqueous electrolyte according to the Second Invention will be described below. The non-aqueous electrolyte of this disclosure comprises: (II) a compound represented by the general formula (II), (III) a solute, and (IV) a non-aqueous organic solvent. The components (II), (III), and (IV) can be replaced with the components described above, so their descriptions will be omitted.

[0072] The content of compound (II) in the non-aqueous electrolyte can be 1 ppm by mass or more and 90 ppm by mass or less, preferably 2 ppm by mass or more and 85 ppm by mass or less, more preferably 3 ppm by mass or more and 80 ppm by mass or less. The content of compound (II) in the non-aqueous electrolyte can be 1 ppm by mass or more, preferably 2 ppm by mass or more, more preferably 3 ppm by mass or more. The content of compound (II) in the non-aqueous electrolyte can be 90 ppm by mass or less, preferably 85 ppm by mass or less, more preferably 80 ppm by mass or less. By containing compound (II) in the above amounts in the non-aqueous electrolyte of this disclosure, the initial battery resistance can be reduced.

[0073] The non-aqueous electrolyte of this disclosure may further contain the compound represented by the general formula (I) described above. The compound (I) is preferably included in 100 parts by mass of the non-aqueous electrolyte of this disclosure in an amount of 0.1 parts by mass or more and 1.5 parts by mass or less, more preferably 0.2 parts by mass or more and 1.3 parts by mass or less, and even more preferably 0.3 parts by mass or more and 1.2 parts by mass or less. The compound (I) is preferably included in 100 parts by mass of the non-aqueous electrolyte of this disclosure in an amount of 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, and even more preferably 0.3 parts by mass or more. The compound (I) is preferably included in 100 parts by mass of the non-aqueous electrolyte of this disclosure in an amount of 1.5 parts by mass or less, more preferably 1.3 parts by mass or less, and even more preferably 1.2 parts by mass or less. By including the compound (I) together with the compound (II) in the above amounts, the battery resistance can be reduced from the initial stage to after the cycle. The non-aqueous electrolyte of this disclosure may further contain the above-mentioned additives and other components that may be included, as needed.

[0074] The non-aqueous electrolyte of this disclosure is suitably used in non-aqueous electrolyte batteries (preferably non-aqueous electrolyte secondary batteries).

[0075] 3. Additive composition for non-aqueous electrolyte The additive composition for non-aqueous electrolyte of this disclosure comprises (I) a compound represented by the general formula (I) and (II) a compound represented by the general formula (II). Since the compounds (I) and (II) can be the same as those used in the non-aqueous electrolyte of this disclosure, no further explanation is provided.

[0076] The additive composition for non-aqueous electrolytes of this disclosure may contain compound (II) in an amount of 0.01 parts by mass or more and 2 parts by mass or less, preferably 0.02 parts by mass or more and 1.5 parts by mass or less, more preferably 0.03 parts by mass or more and 1.0 part by mass or less, even more preferably 0.04 parts by mass or more and 0.95 parts by mass or less, and particularly preferably 0.05 parts by mass or more, in an amount of 0.05 parts by mass or more, in an amount of 0.01 parts by mass or more, preferably 0.02 parts by mass or more, more preferably 0.03 parts by mass or more, even more preferably 0.04 parts by mass or more, and particularly preferably 0.05 parts by mass or more, in an amount of1 parts by mass or more, preferably 0.02 parts by mass or more, more preferably 0.03 parts by mass or more, even more preferably 0.04 parts by mass or more, and particularly preferably 0.05 parts by mass or more, in a total of 100 parts by mass of compound (I) and compound (II). The additive composition for non-aqueous electrolytes of this disclosure may contain compound (II) in an amount of 2 parts by mass or less, preferably 1.5 parts by mass or less, more preferably 1.0 part by mass or less, even more preferably 0.95 parts by mass or less, and particularly preferably 0.90 parts by mass or less, in a total of 100 parts by mass of compound (I) and compound (II). By using the additive composition for non-aqueous electrolytes of this disclosure in a non-aqueous electrolyte, the battery resistance can be further reduced.

[0077] The additive composition for non-aqueous electrolytes of this disclosure can be used to prepare a non-aqueous electrolyte by adding the compound (I) in an amount of 0.1 parts by mass or more and 1.5 parts by mass or less, preferably 0.2 parts by mass or more and 1.3 parts by mass or less, more preferably 0.3 parts by mass or more and 1.2 parts by mass or less, to 100 parts by mass of a non-aqueous electrolyte. The additive composition for non-aqueous electrolytes of this disclosure can be used to prepare a non-aqueous electrolyte by adding the compound (I) in an amount of 0.1 parts by mass or more, preferably 0.2 parts by mass or more, more preferably 0.3 parts by mass or more, to 100 parts by mass of a non-aqueous electrolyte. The additive composition for non-aqueous electrolytes of this disclosure can be used to prepare a non-aqueous electrolyte by adding the compound (I) in an amount of 1.5 parts by mass or less, preferably 1.3 parts by mass or less, more preferably 1.2 parts by mass or less, to 100 parts by mass of a non-aqueous electrolyte. Furthermore, the components (III) and (IV) described above, the additives described above, and other components that may be contained can be added as needed to prepare a non-aqueous electrolyte. A non-aqueous electrolyte containing the additive composition for non-aqueous electrolytes of this disclosure is suitably used in a non-aqueous electrolyte battery (preferably a non-aqueous electrolyte secondary battery).

[0078] Furthermore, the additive composition for non-aqueous electrolytes of this disclosure may contain compound (I) and compound (II) in the following amounts.

[0079] Furthermore, the additive composition for non-aqueous electrolytes of this disclosure contains compound (II) in an amount of 0.01 parts by mass or more and 2 parts by mass or less in a total of 100 parts by mass of compound (I) and compound (II), and the non-aqueous electrolyte may be prepared by adding the additive composition so that compound (I) is present in an amount of 0.1 parts by mass or more and 1.5 parts by mass or less in 100 parts by mass of non-aqueous electrolyte. Alternatively, the additive composition for non-aqueous electrolytes of this disclosure contains compound (II) in an amount of 0.02 parts by mass or more and 1.5 parts by mass or less in a total of 100 parts by mass of compound (I) and compound (II), and the non-aqueous electrolyte may be prepared by adding the additive composition so that compound (I) is present in an amount of 0.2 parts by mass or more and 1.3 parts by mass or less in 100 parts by mass of non-aqueous electrolyte. Furthermore, the additive composition for non-aqueous electrolytes of this disclosure contains compound (II) in an amount of 0.03 parts by mass or more and 1.0 parts by mass or less in a total of 100 parts by mass of compound (I) and compound (II), and may be added to 100 parts by mass of non-aqueous electrolyte in an amount of 0.3 parts by mass or more and 1.2 parts by mass or less to obtain a non-aqueous electrolyte. Alternatively, the additive composition for non-aqueous electrolytes of this disclosure contains compound (II) in an amount of 0.04 parts by mass or more and 0.95 parts by mass or less in a total of 100 parts by mass of compound (I) and compound (II), and may be added to 100 parts by mass of non-aqueous electrolyte in an amount of 0.3 parts by mass or more and 1.2 parts by mass or less to obtain a non-aqueous electrolyte. Furthermore, the additive composition for non-aqueous electrolytes of this disclosure may be prepared by adding the (II) compound in an amount of 0.05 parts by mass or more and 0.90 parts by mass or less in a total of 100 parts by mass of compound (I) and compound (II), and by adding the (II) compound in an amount of 0.3 parts by mass or more and 1.2 parts by mass or less in 100 parts by mass of non-aqueous electrolyte.

[0080] Furthermore, the additive composition for non-aqueous electrolytes of this disclosure contains compound (II) in an amount of 0.01 parts by mass or more and 2 parts by mass or less in a total of 100 parts by mass of compound (I) and compound (II), and compound (I) is one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate. Furthermore, the additive composition for non-aqueous electrolytes of this disclosure contains compound (II) in an amount of 0.02 parts by mass or more and 1.5 parts by mass or less in a total of 100 parts by mass of compound (I) and compound (II), and compound (I) is one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate. Furthermore, the additive composition for non-aqueous electrolytes of this disclosure contains compound (II) in an amount of 0.03 parts by mass or more and 1.0 parts by mass or less in a total of 100 parts by mass of compound (I) and compound (II), and compound (I) is one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate. Furthermore, the additive composition for non-aqueous electrolytes of this disclosure contains compound (II) in an amount of 0.04 parts by mass or more and 0.95 parts by mass or less in a total of 100 parts by mass of compound (I) and compound (II), and compound (I) is one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate.Furthermore, the additive composition for non-aqueous electrolytes of this disclosure contains compound (II) in an amount of 0.05 parts by mass or more and 0.90 parts by mass or less in a total of 100 parts by mass of compound (I) and compound (II), and compound (I) may be one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate.

[0081] Furthermore, the additive composition for non-aqueous electrolytes of this disclosure contains compound (II) in an amount of 0.01 parts by mass or more and 2 parts by mass or less in a total of 100 parts by mass of compound (I) and compound (II), and a non-aqueous electrolyte can be prepared by adding compound (I) in an amount of 0.1 parts by mass or more and 1.5 parts by mass or less in 100 parts by mass of non-aqueous electrolyte, and compound (I) may be one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate. Furthermore, the additive composition for non-aqueous electrolytes of this disclosure contains compound (II) in an amount of 0.02 parts by mass or more and 1.5 parts by mass or less in a total of 100 parts by mass of compound (I) and compound (II), and can be added to 100 parts by mass of non-aqueous electrolyte in an amount of 0.2 parts by mass or more and 1.3 parts by mass or less of compound (I) to make a non-aqueous electrolyte, and compound (I) may be one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate. Furthermore, the additive composition for non-aqueous electrolytes of this disclosure contains compound (II) in an amount of 0.03 parts by mass or more and 1.0 parts by mass or less in a total of 100 parts by mass of compound (I) and compound (II), and can be added to 100 parts by mass of non-aqueous electrolyte in an amount of 0.3 parts by mass or more and 1.2 parts by mass or less of compound (I) to make a non-aqueous electrolyte, and compound (I) may be one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate.Furthermore, the additive composition for non-aqueous electrolytes of this disclosure contains compound (II) in an amount of 0.04 parts by mass or more and 0.95 parts by mass or less in a total of 100 parts by mass of compound (I) and compound (II), and can be added to 100 parts by mass of non-aqueous electrolyte in an amount of 0.3 parts by mass or more and 1.2 parts by mass or less of compound (I) to make a non-aqueous electrolyte, and compound (I) may be one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate. Furthermore, the additive composition for non-aqueous electrolytes of this disclosure contains compound (II) in an amount of 0.05 parts by mass or more and 0.90 parts by mass or less in a total of 100 parts by mass of compound (I) and compound (II), and can be added to 100 parts by mass of non-aqueous electrolyte in an amount of 0.3 parts by mass or more and 1.2 parts by mass or less of compound (I) to make a non-aqueous electrolyte, and compound (I) may be one selected from the group consisting of lithium difluorophosphate and sodium difluorophosphate, and compound (II) may be one selected from the group consisting of ethyllithium monofluorophosphate and ethylsodium monofluorophosphate.

[0082] 4. Non-aqueous electrolyte battery The non-aqueous electrolyte battery of this disclosure comprises at least the non-aqueous electrolyte of this disclosure, a negative electrode, and a positive electrode. It may also include a separator, an outer casing, etc. Alternatively, a solid electrolyte may be used as a medium for impregnating the non-aqueous electrolyte instead of a separator. Preferably, the non-aqueous electrolyte battery of this disclosure comprises at least a positive electrode, a negative electrode, a separator, and the non-aqueous electrolyte of this disclosure. Preferably, the non-aqueous electrolyte battery of this disclosure is a non-aqueous electrolyte secondary battery.

[0083] [Negative electrode] The negative electrode is not particularly limited, but a material that allows reversible insertion and removal of alkali metal ions such as lithium ions and sodium ions, or alkaline earth metal ions, may be used.

[0084] [Negative electrode active material] For example, in the case of a lithium-ion battery in which the cation is mainly lithium, the negative electrode active material constituting the negative electrode is one that can be doped and dedoped with lithium ions, and includes, for example, carbon materials such as artificial graphite and natural graphite with a d value of 0.340 nm or less on the lattice plane (002) in X-ray diffraction, carbon materials such as hard carbon with a d value of 0.340 nm or more on the lattice plane (002) in X-ray diffraction, lithium metal, lithium metal and alloys of other metals (for example, alloys of lithium metal with one or more metals selected from Si, Sn, and Al, alloys of lithium metal with alloys containing one or more metals selected from Si, Sn, and Al, etc.), intermetallic compounds of lithium metal and other metals, metal oxides (for example, oxides of one or more metals selected from Si, Sn, and Al, lithium titanium oxide, etc.), metal nitrides, tin (elementary), tin compounds, activated carbon, and conductive polymers, containing one or more of these.

[0085] Furthermore, a suitable negative electrode active material can be one containing Si and / or Si metal oxide and a carbon material. The above Si is silicon metal. The Si metal oxide may also be a compound represented as SiOx (where x is a value of 0.5 to 1.5). In this case, the total content of Si and / or Si metal oxide in the negative electrode active material may be 0.1 to 50% by mass, preferably 0.1 to 30% by mass, when the total amount of the Si and / or Si metal oxide and carbon material in the negative electrode active material is taken as 100% by mass. Graphite is preferred as the carbon material, and various types of artificial graphite, natural graphite, or hard carbon (non-graphitizable carbon) can be used. Graphite exhibits very little change in its crystal structure during lithium intercalation and release, resulting in high energy density and excellent cycle characteristics. The shape of the graphite may be fibrous, spherical, granular, or flaky. Furthermore, amorphous carbon or graphite coated with amorphous carbon is preferable because it reduces the reactivity between the material surface and the electrolyte. These negative electrode active materials can be used individually or in combination of two or more.

[0086] For example, in the case of a sodium-ion battery in which the cation is mainly sodium, the negative electrode active material that constitutes the negative electrode may be sodium metal, alloys of sodium metal and other metals such as tin, intermetallic compounds of sodium metal and other metals, various carbon materials including hard carbon, metal oxides such as titanium oxide, metal nitrides, elemental tin, tin compounds, activated carbon, conductive polymers, etc. In addition to these, elemental phosphorus such as red phosphorus and black phosphorus, phosphorus compounds such as Co-P, Cu-P, Sn-P, Ge-P, and Mo-P, elemental antimony, antimony compounds such as Sb / C and Bi-Sb, etc. These negative electrode active materials may be used individually or in combination of two or more types.

[0087] [Negative Electrode Current Collector] The negative electrode has a negative electrode current collector. For example, copper, stainless steel, nickel, titanium, or alloys thereof can be used as the negative electrode current collector. In addition, aluminum or its alloys can be used in sodium-ion batteries.

[0088] [Negative Electrode Active Material Layer] The negative electrode is formed by creating a negative electrode active material layer on at least one surface of the negative electrode current collector. The negative electrode active material layer is composed of, for example, the aforementioned negative electrode active material, a binder, and a conductive agent as needed. Examples of binders include polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, styrene-butadiene rubber (hereinafter also referred to as "SBR"), carboxymethylcellulose, methylcellulose, cellulose phthalate acetate, hydroxypropylmethylcellulose, polyvinyl alcohol, and polyimide. Examples of conductive agents include acetylene black, Ketjen black, furnace black, carbon fiber, graphite, fluorinated graphite, and other carbon materials.

[0089] [Positive electrode] The positive electrode is not particularly limited, but a material that allows reversible insertion and removal of alkali metal ions such as lithium ions and sodium ions, or alkaline earth metal ions, may be used.

[0090] [Positive Electrode Active Material] For example, when the cation is lithium, as the positive electrode material (positive electrode active material), LiCoO ２ , LiNiO ２ , LiMnO ２ , LiMn ２ O ４ and other lithium-containing transition metal composite oxides, those in which transition metals such as Co, Mn, Ni of these lithium-containing transition metal composite oxides are mixed in plural, or those in which a part of the transition metal of these lithium-containing transition metal composite oxides is replaced with a metal other than another transition metal may be used.

[0091] Specifically, Li[Ni 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, may be 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 ０．８５ Co 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 O２ LiNi ０．６ Co ０．３ Al ０．１ O ２ LiNi ０．５ Mn １．５ O ４ LiNi ０．５ Mn ０．５ O ２ LiNi ０．１ Mn １．９ O ４ LiCo ０．５ Mn ０．５ O ２ , 0.5[LiNi ０．５ Mn ０．５ O ２ ]・0.5[Li ２ MnO ３ ], 0.5[LiNi １／３ Co １／３ Mn １／３ O ２ ]・0.5[Li ２ MnO ３ ], 0.5[LiNi ０．３７５ Co ０．２５ Mn ０．３７５ O ２ ]・0.5[Li ２ MnO ３ ], 0.5[LiNi ０．３７５ Co ０．１２５ Fe ０．１２５ Mn ０．３７５ O ２ ]・0.5[Li ２ MnO ３ ], 0.45[LiNi ０．３７５ Co ０．２５ Mn ０．３７５ O ２ ]・0.10[Li ２ TiO ３ ]・0.45[Li ２ MnO ３ Examples include:

[0092] Also, Li called olivine α M ００１ PO ４ Compounds represented by (0 < α ≤ 1) may also be used. ００１ is at least one element selected from the group consisting of Mn, Fe, Co, or Ni. ００１From the viewpoint of battery capacity and cycle characteristics, it is preferable that the mixture contains Fe, Mn, or both Fe and Mn, and more preferably Fe or both Fe and Mn. ００１ A portion of it can be substituted with other elements such as Mg, Al, Ti, V, Cr, Zr, etc. Furthermore, the olivine-type positive electrode active material may have one or more elements selected from the group consisting of B, C, N, F, Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, Zn, Zr, and W present on part or all of its particle surface, either as individual elements or compounds thereof. Specifically, LiFePO ４ LiCoPO ４ LiMnPO ４ LiNiPO ４ LiFe ０．５ Mn ０．５ PO ４ LiFe ０．４ Mn ０．６ PO ４ LiFe ０．３ Mn ０．７ PO ４ LiFe ０．５ Mn ０．４ Mg ０．１ PO ４ LiFe ０．５ Mn ０．４５ Zr ０．０５ PO ４ Examples include phosphate compounds of transition metals such as the following.

[0093] Also, TiO ２ , V ２ O ５ MoO ３ Oxides such as TiS ２ FeS, MoS ２ Sulfides such as those mentioned above, or conductive polymers such as polyacetylene, poly(p-phenylene), polyaniline, and polypyrrole, activated carbon, radical-generating polymers, carbon materials, etc. may also be used.

[0094] For example, if the cation is sodium, the positive electrode material (positive electrode active material) would be NaCrO ２ NaFe ０．５ Co ０．５ O ２ NaFe ０．４ Mn ０．３Ni 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, mixtures of multiple transition metals such as Co, Mn, and Ni in these sodium-containing transition metal composite oxides, and in which some of the transition metals in these sodium-containing transition metal composite oxides are replaced with other metals other than transition metals, NaFePO ４ NaVPO ４ F, Na ３ V ２ (PO ４ ) ３ Na ２ Fe ２ (SO ４ ) ３ Polyanionic compounds such as, composition formula Na β M ００２ γ [Fe(CN)] ６ ] δ The sodium salt of the Prussian blue analog represented by (M ００２ = Represents Cr, Mn, Fe, Co, Ni, Cu, or Zn, with 0 ≤ β ≤ 2, 0.5 ≤ γ ≤ 1.5, 0.5 ≤ δ ≤ 1.5), TiO ２ , V ２ O ５ MoO ３ Oxides such as TiS ２ FeS, MoS ２Sulfides such as those mentioned above, or conductive polymers such as polyacetylene, poly(p-phenylene), polyaniline, and polypyrrole, activated carbon, radical-generating polymers, carbon materials, etc. may also be used.

[0095] [Positive electrode current collector] The positive electrode has a positive electrode current collector. As the positive electrode current collector, for example, aluminum, stainless steel, nickel, titanium, or alloys thereof can be used.

[0096] [Positive Electrode Active Material Layer] The positive electrode is formed by creating a positive electrode active material layer on at least one surface of the positive electrode current collector. The positive electrode active material layer is composed of, for example, the positive electrode active material described above, a binder, and a conductive agent as needed. The binder is the same as described in [Negative Electrode Active Material Layer]. As the conductive agent, carbon materials such as acetylene black, Ketjen black, furnace black, carbon fiber, graphite (granular graphite or flake graphite), and fluorinated graphite can be used. In the positive electrode, it is preferable to use acetylene black or Ketjen black with low crystallinity.

[0097] [Method for manufacturing electrodes (positive and negative electrodes)] Electrodes can be obtained, for example, by dispersing and kneading an active material, a binder, and optionally a conductive agent in predetermined proportions in a solvent such as N-methyl-2-pyrrolidone (hereinafter sometimes referred to as "NMP") or water, applying the resulting paste to a current collector, and drying it to form an active material layer. It is preferable to compress the obtained electrodes using a method such as a roll press to adjust them to an electrode of appropriate density.

[0098] [Separator] The non-aqueous electrolyte battery of this disclosure may be equipped with a separator. As a separator to prevent contact between the positive electrode and the negative electrode, for example, nonwoven fabrics or porous sheets made of polyolefins such as polypropylene and polyethylene, cellulose, paper, glass fiber, etc. are used. These films are preferably microporous so that the electrolyte can permeate and ions can easily pass through. As a polyolefin separator, for example, a microporous polymer film such as a porous polyolefin film is used, which electrically insulates the positive electrode and the negative electrode and allows lithium ions to pass through.Specific examples of porous polyolefin films include, for example, a porous polyethylene film alone, or a porous polyethylene film and a porous polypropylene film layered together to form a multilayer film. Another example is a film made by compounding a porous polyethylene film and a polypropylene film.

[0099] The non-aqueous electrolyte of this disclosure may be impregnated into and retained in the separator described above. There are no particular restrictions on the impregnation method, and any known method may be used. Specifically, impregnation can be achieved by pouring the electrolyte into a battery comprising a positive electrode, a separator, and a negative electrode as the final step.

[0100] [Outer casing] Suitable outer casings for the non-aqueous electrolyte battery of this disclosure include, for example, coin-type, cylindrical, or rectangular metal cans, as well as laminated outer casings. Suitable metal can materials include, for example, nickel-plated steel, stainless steel, nickel-plated stainless steel, aluminum or its alloys, nickel, titanium, etc. Suitable laminated outer casings include, for example, aluminum laminate film, SUS laminate film, silica-coated polypropylene, polyethylene laminate film, etc.

[0101] The configuration of the non-aqueous electrolyte battery according to this embodiment is not particularly limited, but for example, it can be configured such that electrode elements with a positive electrode and a negative electrode facing each other and a non-aqueous electrolyte are enclosed in an outer casing. The shape of the non-aqueous electrolyte battery is not particularly limited, but an electrochemical device in the shape of a coin, cylinder, prismatic, or aluminum laminate sheet can be assembled from the above elements.

[0102] 5. Method for Manufacturing a Non-Aqueous Electrolyte Battery The method for manufacturing a non-aqueous electrolyte battery according to this disclosure includes a step of injecting the non-aqueous electrolyte described above. There are no particular restrictions on the method of injection, and it can be carried out by conventional methods. For example, vacuum injection is one example.

[0103] Although embodiments of the present invention have been described above, these are merely examples, and various other configurations can be adopted as long as they do not impair the effects of the present invention.

[0104] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to such examples. In the table, "-" indicates that there is no data (not measured), and "N.D." indicates that it was not detected (measured but below the detection limit).

[0105] <Example a related to lithium-ion batteries> [Synthesis example a1-1] Ethyl difluorophosphate (POF ２ Synthesis of OEt) 1. 500 mL of acetonitrile and 81.5 g (500 mmol) of ethyl dichlorophosphate were added to a 1 L fluoropolymer reactor and stirred until thoroughly mixed. After adding 174.3 g (3000 mmol) of potassium fluoride, stirring was continued at a liquid temperature of 25°C for 12 hours. １９ F-NMR confirmed that the resulting reaction solution contained the target product, ethyl difluorophosphate (POF). ２ OEt) is 90% by mass, potassium hexafluorophosphate (KPF) ６ ) contains 4% by mass, diethyl monofluorophosphate (POF(OEt) ２It was confirmed that 6% by mass of ) was present. The reaction equation is shown below. After removing potassium chloride by filtration, the target product was obtained by vacuum distillation, separating it into each distillation fraction as shown in Table 1 below. Table 1 shows the molar percentage of the components contained in each distillation fraction. Note that distillation fraction Fr. 0 is the fraction from which acetonitrile was removed by distillation.

[0106] [Synthesis Example a1-2] Ethyl difluorophosphate (POF ２ Synthesis of OEt) 2 500 mL of acetonitrile and 81.5 g (500 mmol) of ethyl dichlorophosphate were added to a 1 L fluoropolymer reactor and stirred until thoroughly mixed. After adding 174.3 g (3000 mmol) of potassium fluoride, stirring was continued at a liquid temperature of 25°C for 12 hours. １９ F-NMR confirmed that the resulting reaction solution contained the target product, ethyl difluorophosphate (POF). ２ OEt) is 90% by mass, potassium hexafluorophosphate (KPF) ６ ) contains 4% by mass, diethyl monofluorophosphate (POF(OEt) ２ It was confirmed that 6% by mass of ) was present. After removing potassium chloride by filtration, the target product (fraction) was obtained by vacuum distillation. Table 1 shows the mass percentages of the components contained in the target product (fraction).

[0107]

[0108] [Synthesis Examples a2-1 to a2-5, Synthesis Example a3] Lithium difluorophosphate (LiPO ２ F ２ Synthesis of ) 10 mL of ethyl methyl carbonate (EMC) and 0.42 g of anhydrous lithium chloride were placed in a 50 mL glass reactor, and stirring was started at an internal temperature of 40°C. Then, 1.3 g (10 mmol) of ethyl difluorophosphate from distillation fraction Fr. 1 obtained by the procedure of Synthesis Example a1-1 was added over 1 hour. After that, stirring was continued at an internal temperature of 40°C for 12 hours. After lowering the internal temperature to below 25°C, the precipitated solid was collected by filtration, and after drying under reduced pressure at 80°C, lithium difluorophosphate (LiPO) was obtained with a yield of 98% and purity of 99%. ２ F ２A reaction product containing ) was obtained. The main impurity contained in the reaction product was ethyl lithium monofluorophosphate (LiPO4 ２ The solution consisted of 0.01% by mass of diethyl monofluorophosphate (POF(OEt)) and the solvent EMC (Synthesis Example a2-1). Furthermore, lithium difluorophosphate was synthesized in the same manner as above using the distillation fractions Fr. 2-5 obtained in Synthesis Example a1-1, and the fraction obtained in Synthesis Example a1-2 (Synthesis Examples a2-2 to a2-5, Synthesis Example a3). The reaction equation is shown below. Table 2 shows the "Diethyl monofluorophosphate (POF(OEt)) before reaction" contained in the distillation fraction. ２ ) Content (mass%) and "Post-reaction ethyl lithium monofluorophosphate (LiPO)" contained in the reaction product ２ This indicates the F(OEt) content (mass%). As shown in Table 2, diethyl monofluorophosphate (POF(OEt) ２ When lithium difluorophosphate is synthesized using a distillation fraction with a high content of ), ethyl lithium monofluorophosphate (LiPO) is produced as a byproduct. ２ The amount of F(OEt) increased.

[0109] [Synthesis Example a4] Lithium difluorophosphate (LiPO) ２ F ２ Synthesis of (alternative method): 15.2 g (100 mmol) of lithium hexafluoride phosphate, 50 ml of dimethyl carbonate, and hexamethyldisiloxane (TMS) are added to a 100 mL glass reactor. ２ O) 35.7 g (220 mmol) was added and the mixture was stirred at 60°C for 24 hours. After the reaction was complete, the precipitated solid was collected by filtration and dried under reduced pressure at 80°C to obtain lithium difluorophosphate (reaction product) with a yield of 88% and a purity of 99%. The reaction equation is shown below. From the obtained reaction product, ethyl lithium monofluorophosphate (LiPO) ２ F(OEt)) was not detected.

[0110]

[0111] [Synthesis Example a5] Lithium monofluorophosphate (Li ２ PO３ Synthesis of F) 1.7 g (10 mmol) of 60% monofluorophosphate aqueous solution was added to 0.37 g (5 mmol) of lithium carbonate in a 30 mL glass reactor, and the mixture was stirred at 25°C for 2 hours. After the reaction was complete, insoluble matter was removed by filtration, and then lithium monofluorophosphate (Li) was dried under reduced pressure in a yield of 98% with a purity of 95%. ２ PO ３ F) was obtained.

[0112] [Example a1-1] (Preparation of non-aqueous electrolyte) In a glove box with a dew point of -60°C or lower, EC, FEC, EMC, and DMC were mixed in a volume ratio of EC:FEC:EMC:DMC = 25:5:45:25. Then, while maintaining the internal temperature at 40°C or lower, an amount of LiPFF to a concentration of 1.0 mol / L was added. ６ Adding the reaction product obtained in synthesis example a2-1, the total amount of non-aqueous electrolyte is lithium difluorophosphate (LiPO) ２ F ２ ) was added to a concentration of 1.0 mass%, and the mixture was stirred for 24 hours to dissolve it, thereby preparing the non-aqueous electrolyte a1-1 of Example a1-1. The above abbreviations are as follows: EC: ethylene carbonate FEC: fluoroethylene carbonate EMC: ethyl methyl carbonate DMC: dimethyl carbonate (Preparation of non-aqueous electrolyte battery) Using the obtained non-aqueous electrolyte, a non-aqueous electrolyte battery was prepared by the following procedure. In an argon atmosphere with a dew point of -50°C or lower, a test NCM811 positive electrode and a test natural graphite negative electrode were placed via a polyethylene separator impregnated with the test electrolyte, and a non-aqueous electrolyte battery (lithium-ion battery) with an aluminum laminate casing was assembled.

[0113] [Examples a1-2 to a1-5, Comparative Examples a1-1 to a1-4] (Preparation of Non-Aqueous Electrolyte) Instead of the reaction product obtained in Synthesis Example a2-1, the reaction products obtained in Synthesis Examples a2-2 to a2-5, Synthesis Example a3, and Synthesis Example a4 were used as shown in Table 3, Lithium Difluorophosphate (LiPO) ２ F ２Except for adding the solution to achieve the concentration specified above, the non-aqueous electrolytes a1-2 to a1-5 of Examples a1-2 to a1-5 and comparative non-aqueous electrolytes a1-1 to a1-4 of Comparative Examples a1-1 to a1-4 were prepared in the same manner as in Example a1-1. (Preparation of non-aqueous electrolyte battery) Except for using the non-aqueous electrolytes listed in Table 3, the non-aqueous electrolyte battery was assembled in the same manner as in Example a1-1.

[0114] [Comparative Example a1-5] Comparison of Non-Aqueous Electrolyte Preparation The non-aqueous electrolyte prepared in non-aqueous electrolyte a1-1 was compared with the lithium monofluorophosphate (Li) synthesized in synthesis example a5. ２ PO ３ F) was added to the total amount of the non-aqueous electrolyte at a concentration of 90 ppm by mass, and stirred for 24 hours to dissolve, thereby preparing comparative non-aqueous electrolyte a1-5 for comparative example a1-5. (Preparation of non-aqueous electrolyte battery) A non-aqueous electrolyte battery was assembled in the same manner as in example a1-1, except that the non-aqueous electrolyte listed in Table 3 was used.

[0115] The manufactured non-aqueous electrolyte batteries were evaluated using the following method. The results are shown in Table 3.

[0116] <Evaluation Method> -Lithium-ion battery: Initial charge and discharge- The fabricated non-aqueous electrolyte battery was placed in a 25°C constant temperature bath and connected to a charge / discharge device. It was charged to 4.3V at 3mA. After maintaining 4.3V for 1 hour, it was discharged to 2.5V at 6mA. This constituted one charge / discharge cycle, and the battery was stabilized by performing a total of three charge / discharge cycles. [Lithium-ion battery: High-temperature cycle test] The non-aqueous electrolyte battery stabilized by the above initial charge / discharge was subjected to a charge / discharge test at an ambient temperature of 60°C to evaluate its high-temperature cycle characteristics. With a maximum charge voltage of 4.3V and a minimum discharge voltage of 2.5V, the charge / discharge cycle was repeated at a current of 30mA using the constant current / constant voltage method. Then, the resistance measurement described below was performed on the non-aqueous electrolyte battery at the 700th cycle of the charge / discharge test at an ambient temperature of 60°C. [Lithium-ion battery: Resistance measurement after high-temperature cycle test] After the high-temperature cycle test described above, the non-aqueous electrolyte battery was charged to 4.3V at 25°C and 6mA, and then the resistance was measured by impedance measurement in an environment of -20°C. The resistance value was expressed as a relative value with comparative example a1-1 set to 100.0. The results are shown in Table 3.

[0117]

[0118] From the results shown in Table 3, ethyl lithium monofluorophosphate (LiPO) is used in relation to non-aqueous electrolytes. ２ It was found that the battery resistance was reduced after high-temperature cycling tests when the content of F(OEt)) was between 1 ppm by mass and 200 ppm by mass. Examples a1-5 showed reduced resistance values ​​compared to comparative examples a1-2. Furthermore, ethyl difluorophosphate (POF) synthesized according to conventional methods as in synthesis example a1-2 was also found. ２ Using OEt, lithium difluorophosphate (LiPO) ２ F ２ When ) is synthesized (synthesis example a3), as shown in Comparative Example a1-4, ethyl lithium monofluorophosphate (LiPO) in the non-aqueous electrolyte ２ The high content of F(OEt) at 210 ppm resulted in increased battery resistance after high-temperature cycle testing.

[0119] <Example b relating to sodium-ion batteries> [Synthesis example b1-1] Ethyl difluorophosphate (POF ２ Synthesis of OEt) 1 Similar to synthesis example a1-1, ethyl difluorophosphate (POF) listed in Table 1 was synthesized. ２ Each distillation fraction containing OEt was obtained.

[0120] [Synthesis example b1-2] Ethyl difluorophosphate (POF ２ Synthesis of OEt) 2 The target product (fraction) shown in Table 1 was obtained in the same manner as in Synthesis Example a1-2.

[0121] [Synthesis Examples b2-1 to b2-4] Sodium difluorophosphate (NaPO ２ F ２ Synthesis of sodium difluorophosphate (NaPO4) 10 mL of ethyl methyl carbonate (EMC) and 1.5 g of sodium iodide were placed in a 50 mL glass reactor, and stirring was started at an internal temperature of 25°C. 1.3 g (10 mmol) of ethyl difluorophosphate from distillation fraction Fr. 1 obtained in synthesis example b1-1 was added over 1 hour. Stirring was then continued at an internal temperature of 25°C for 12 hours. After the reaction was complete, the precipitated solid was collected by filtration and dried under reduced pressure at 80°C to obtain sodium difluorophosphate (NaPO4) with a yield of 98% and purity of 99%. ２ F ２ A reaction product containing ) was obtained. The main impurity contained in the reaction product was sodium ethyl monofluorophosphate (NaPO ２ The solution consisted of 0.01% F(OEt) and the solvent EMC (Synthesis Example b2-1). Furthermore, sodium difluorophosphate was synthesized in the same manner as above using the distillation fractions Fr. 2, 3, and 5 obtained in Synthesis Example b1-1, and the fraction obtained in Synthesis Example b1-2 (Synthesis Examples b2-2 to b2-4, Synthesis Example b3). The reaction equation is shown below. Table 4 shows the "Diethyl monofluorophosphate (POF(OEt) before reaction" contained in the distillation fraction. ２ ) Content (mass%) and "Ethyl sodium monofluorophosphate (NaPO) after reaction" contained in the reaction product ２ This indicates the F(OEt) content (mass%). As shown in Table 4, diethyl monofluorophosphate (POF(OEt) ２When sodium difluorophosphate is synthesized using a distillation fraction with a high content of ), ethyl sodium monofluorophosphate (NaPO) is produced as a byproduct. ２ The amount of F(OEt) increased.

[0122] [Synthesis example b4] Sodium difluorophosphate (NaPO ２ F ２ Synthesis of (alternative method): 16.8 g (100 mmol) of sodium hexafluoride phosphate, 50 ml of dimethyl carbonate, and hexamethyldisiloxane (TMS) are added to a 100 mL glass reactor. ２ O) 35.7 g (220 mmol) was added and the mixture was stirred at 60°C for 24 hours. After the reaction was complete, the precipitated solid was collected by filtration and dried under reduced pressure at 80°C to obtain sodium difluorophosphate (reaction product) with a yield of 88% and a purity of 99%. The reaction equation is shown below. From the obtained reaction product, ethyl sodium monofluorophosphate (NaPO) ２ F(OEt)) was not detected.

[0123]

[0124] [Example b1-1] (Preparation of non-aqueous electrolyte) PC, EC, FEC, and EMC were mixed in a glove box with a dew point of -60°C or lower in a volume ratio of PC:EC:FEC:EMC = 20:10:2:68. Then, while maintaining the internal temperature at 40°C or lower, an amount of NaPF was added to achieve a concentration of 1.0 mol / L. ６ Add the reaction product obtained in synthesis example b2-1 to the total amount of non-aqueous electrolyte, and add sodium difluorophosphate (NaPO ２ F ２) was added to a concentration of 1.0% by mass, and the mixture was stirred for 24 hours to dissolve it, thereby preparing the non-aqueous electrolyte b1-1 of Example b1-1. The above abbreviations are as follows: PC: Propylene carbonate EC: Ethylene carbonate FEC: Fluoroethylene carbonate EMC: Ethyl methyl carbonate (Preparation of non-aqueous electrolyte battery) Using the obtained non-aqueous electrolyte, a non-aqueous electrolyte battery was prepared by the following procedure. In an argon atmosphere with a dew point of -50°C or lower, test NaNi was passed through a polyethylene separator impregnated with the test electrolyte. ０．５ Ti ０．３ Mn ０．２ O ２ A non-aqueous electrolyte battery (sodium-ion battery) was assembled by positioning a positive electrode and a test hard carbon negative electrode, and encasing it in an aluminum laminate casing.

[0125] [Examples b1-2 to b1-3, Comparative Examples b1-1 to b1-3] (Preparation of non-aqueous electrolyte) Instead of the reaction product obtained in synthesis example b2-1, the reaction products obtained in synthesis examples b2-2 to b2-4, synthesis example b3, and synthesis example b4 were used as shown in Table 5, sodium difluorophosphate (NaPO ２ F ２ Except for adding to achieve the concentration of ), the non-aqueous electrolytes b1-2 to b1-3 of Examples b1-2 to b1-3 and comparative non-aqueous electrolytes b1-1 to b1-3 of Comparative Examples b1-1 to b1-3 were prepared in the same manner as in Example b1-1. (Preparation of non-aqueous electrolyte battery) Except for using the non-aqueous electrolytes listed in Table 3, the non-aqueous electrolyte battery was assembled in the same manner as in Example b1-1.

[0126] [Comparative Example b1-4] (Preparation of Non-Aqueous Electrolyte) Sodium monofluorophosphate (Na) was added to the non-aqueous electrolyte prepared with comparative non-aqueous electrolyte b1-1. ２ PO ３ Comparative non-aqueous electrolyte b1-4 of Comparative Example b1-4 was prepared by adding F (manufactured by Aldrich) to the total amount of non-aqueous electrolyte at a concentration of 60 ppm by mass, and stirring for 24 hours to dissolve it. (Preparation of non-aqueous electrolyte battery) A non-aqueous electrolyte battery was assembled in the same manner as in Example b1-1, except that the non-aqueous electrolyte listed in Table 3 was used.

[0127] The manufactured non-aqueous electrolyte batteries were evaluated using the following method. The results are shown in Table 5.

[0128] <Evaluation Method> -Sodium-ion battery: Initial charge and discharge- The fabricated non-aqueous electrolyte battery was placed in a 25°C constant temperature bath and connected to a charge / discharge device. It was charged to 4.1V at 3mA. After maintaining 4.1V for 1 hour, it was discharged to 1.5V at 6mA. This constituted one charge / discharge cycle, and the battery was stabilized by performing a total of three charge / discharge cycles. [Sodium-ion battery: High-temperature cycle test] The non-aqueous electrolyte battery stabilized by the above initial charge / discharge was subjected to a charge / discharge test at an ambient temperature of 60°C to evaluate its high-temperature cycle characteristics. With a maximum charge voltage of 4.1V and a minimum discharge voltage of 1.5V, the charge / discharge cycle was repeated at a current of 30mA using the constant current / constant voltage method. Then, the resistance measurement described below was performed on the non-aqueous electrolyte battery at the 700th cycle of the charge / discharge test at an ambient temperature of 60°C. [Sodium-ion battery: Resistance measurement after high-temperature cycle test] After the high-temperature cycle test described above, the non-aqueous electrolyte battery was charged to 4.1V at 25°C and 6mA, and then the resistance was measured by impedance measurement in an environment of -20°C. The resistance value was expressed as a relative value with comparative example b1-1 set to 100.0. The results are shown in Table 5.

[0129]

[0130] From the results shown in Table 5, ethyl sodium monofluorophosphate (NaPO) is used in non-aqueous electrolytes. ２ It was found that when the content of F(OEt)) is between 1 ppm by mass and 200 ppm by mass, the battery resistance is reduced after high-temperature cycling tests. Furthermore, as shown in synthesis example b1-2, ethyl difluorophosphate (POF) synthesized according to conventional methods was also found. ２ Using OEt), sodium difluorophosphate (NaPO) ２ F ２ When ) is synthesized (synthesis example b3), as shown in Comparative Example b1-3, ethyl sodium monofluorophosphate (NaPO) in the non-aqueous electrolyte ２ The high content of F(OEt) at 260 ppm by mass resulted in increased battery resistance after high-temperature cycle testing.

[0131] This application claims priority based on Japanese Patent Application No. 2025-010908, filed on 24 January 2025, and incorporates all of its disclosures herein.

Claims

1. A non-aqueous electrolyte comprising: (I) a compound represented by the following general formula (I); (II) a compound represented by the following general formula (II); (III) a solute; and (IV) a non-aqueous organic solvent, wherein the content of compound (II) relative to the non-aqueous electrolyte is 1 ppm by mass or more and 200 ppm by mass or less. (In general formula (I), M ＋ (This represents alkali metal ions.) (In general formula (II), M ＋ (where R represents an alkali metal ion; R represents an organic group selected from alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, aryl groups, and aralkyl groups.) 2. M in the above general formula (I) and the above general formula (II) ＋ The non-aqueous electrolyte according to claim 1, wherein is lithium ions or sodium ions.

3. The non-aqueous electrolyte according to claim 1 or 2, wherein R in the general formula (II) is a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms.

4. (III) The solute is LiPF ６ , LiBF ４ , LiSbF ６ , LiAsF ６ , LiClO ４ , LiN(SO ２ F) ２ , LiAlO[[ID=_15]] ２ , LiAlCl ４ , at least one selected from the group consisting of LiCl and LiI, or NaPF ６ , NaBF ４ , NaSbF ６ , NaAsF ６ , NaClO ４ , NaN(SO ２ F) ２ , NaAlO ２ , NaAlCl ４ , at least one selected from the group consisting of NaCl and NaI, and the non-aqueous electrolyte according to any one of claims 1 to 3 It should be noted that there may be some special chemical formula notations in the original text, and the translation tries to maintain the original form as much as possible. If there are specific requirements for chemical term translation accuracy, it may need to be further adjusted according to relevant chemical knowledge.

5. The non-aqueous electrolyte according to any one of claims 1 to 4, wherein the (I) compound is contained in an amount of 0.1 parts by mass or more and 1.5 parts by mass or less in 100 parts by mass of the non-aqueous electrolyte.

6. (IV) The nonaqueous electrolyte according to any one of claims 1 to 5, wherein the nonaqueous organic solvent comprises at least one selected from the group consisting of cyclic esters, linear esters, cyclic ethers, linear ethers, sulfone compounds, sulfoxide compounds, and ionic liquids.

7. The non-aqueous electrolyte according to claim 6, wherein the cyclic ester comprises a cyclic carbonate.

8. The non-aqueous electrolyte according to claim 7, wherein the cyclic carbonate comprises one or more selected from the group consisting of ethylene carbonate and propylene carbonate.

9. The non-aqueous electrolyte according to any one of claims 6 to 8, wherein the chain-like ester comprises a chain-like carbonate.

10. The non-aqueous electrolyte according to claim 9, wherein the chain-like carbonate comprises one or more selected from the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, and methyl propyl carbonate.

11. The non-aqueous electrolyte according to any one of claims 6 to 10, wherein the cyclic ether comprises one or more selected from the group consisting of tetrahydrofuran, 2-methyltetrahydrofuran, furan, tetrahydropyran, 1,3-dioxane, 1,4-dioxane, 1,3-dioxolane, and trioxane.

12. The non-aqueous electrolyte according to any one of claims 6 to 11, wherein the chain ether comprises one or more selected from the group consisting of diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, dimethoxymethane, trimethoxymethane, 1,2-dimethoxyethane, diethoxyethane, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether.

13. Furthermore, cyclohexylbenzene, cyclohexylfluorobenzene, biphenyl, 2-fluorobiphenyl, tert-butylbenzene, tert-amylbenzene, 2-fluorotoluene, fluorobenzene, difluoroanisole, vinylene carbonate, vinylene carbonate oligomers (number average molecular weight in polystyrene terms of 170-5000), vinylethylene carbonate, divinylethylene carbonate, fluoroethylene carbonate, ethynylethylene carbonate, trans-difluoroethylene carbonate, methylpropargyl carbonate, ethylpropargyl carbonate, dipropargyl carbonate, dimethylvinylene carbonate, dimethyl dicarbonate, bis(1,1,1,3,3,3-hexafluoro-1-propyl) carbonate, bis(2,2,2-trifluoroethyl) carbonate, 1,6-diisocyanatohexa N, maleic anhydride, succinic anhydride, 1,4-dioxan-2,6-dione, glutaric anhydride, methanedisulfonic anhydride, 1,2-ethanedisulfonic anhydride, methanesulfonic anhydride, 2-sulfobenzoic anhydride, 1,3-propanedisulfonic anhydride, 1,3-propanesultone, 1,3-propensultone, 1,4-butanesultone, 2,4-butanesultone, 1,3,2-dioxathiolan-2,2-dioxide, 4-pro Pyr-1,3,2-dioxathiolan-2,2-dioxide, 1,3-dithiolan-1,1,3,3-tetraoxide, 1,3-dithian-1,1,3,3-tetraoxide, 1,2-oxathiolan-5-one-2,2-dioxide, methylene methane disulfate, dimethyl methane disulfate, trimethylene methane disulfate, methyl methanesulfonate, methanesulfonyl fluoride, ethensulfonyl fluoride, N,N'-Carbonylbis(N-methylsulfamoylfluoride), difluoro(picolinato)borate, phenyl difluorophosphate, trippropargyl phosphate, tetrafluoro(picolinato)phosphate, (ethoxy)pentafluorocyclotriphosphazene, succinonitrile, methyldifluorovinylsilane, methylfluorodivinylsilane, dimethyldivinylsilane, trivinylmethylsilane, trivinylfluorosilane, tetravinylsilane, tris(trimethylsilyl)borate, tris(trimethylsilyl)phosphate, 1,3-dimethyl-1,3-divinyl-1,3-di(1,1,1,3,3,3-Hexafluoroisopropyl)disiloxane, fluorosulfonate, trifluoromethanesulfonate, pentafluoroethanesulfonate, nonafluorobutanesulfonate, monomethyl sulfate, monoethyl sulfate, bis(trifluoromethanesulfonyl)imide, bis(pentafluoroethanesulfonyl)imide, (trifluoromethanesulfonyl)(nonafluorobutanesulfonyl)imide, (trifluoromethanesulfonyl)(pentafluoroethanesulfonyl)imide, (trifluoromethanesulfonyl)(fluorosulfonyl)imide, (pentafluoroethanesulfonyl)(fluorosulfonyl)imide, (difluorophosphoryl)(fluorosulfonyl)imide, (difluorophosphoryl)(trifluoromethanesulfonyl)imide, bis(difluorophosphoryl)imide A non-aqueous electrolyte according to any one of claims 1 to 13, containing one or more selected from the group consisting of dihydrochloride salt, (fluorosulfonyl)(carbonyloxymethanesulfonate lithium)imide, (fluorosulfonyl)(carbonyldi(2-propenyl)phosphoryl)imide salt, (carbonyldi(propargyl)phosphoryl)imide salt, tetrafluoro(malonato) phosphate, tris(oxalato) phosphate, difluorobis(oxalato) phosphate, tetrafluorooxalato phosphate, bis(oxalato) borate, difluorooxalatoborate, difluoro(malonato) borate, tris(trifluoromethanesulfonyl)methide salt, tris(fluorosulfonyl)methide salt, acrylate, methacrylate, nitrate, nitrite, hexafluoroisopropanol, and trifluoroethanol.

14. A non-aqueous electrolyte battery comprising at least a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte according to any one of claims 1 to 13.

15. A method for manufacturing a non-aqueous electrolyte battery, comprising the step of injecting a non-aqueous electrolyte according to any one of claims 1 to 13.

16. A non-aqueous electrolyte additive composition containing (I) a compound represented by the following general formula (I) and (II) a compound represented by the following general formula (II), wherein the composition contains 0.01 parts by mass or more and 2 parts by mass or less of compound (II) in a total of 100 parts by mass of compound (I) and compound (II). (In general formula (I), M ＋ (This represents alkali metal ions.) (In general formula (II), M ＋ (where R represents an alkali metal ion; R represents an organic group selected from alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, aryl groups, and aralkyl groups.) 17. M in the above general formula (I) and the above general formula (II) ＋ The additive composition for non-aqueous electrolytes according to claim 16, wherein is lithium ions or sodium ions.

18. The additive composition for non-aqueous electrolyte according to claim 16 or 17, wherein R in the general formula (II) is a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms.

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