JP7116312B2 - Electrolyte for non-aqueous electrolyte battery and non-aqueous electrolyte battery using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electrolyte for non-aqueous electrolyte batteries and a non-aqueous electrolyte battery using the same.

As means for improving the durability of non-aqueous electrolyte batteries, optimization of various battery components including active materials for positive and negative electrodes has been studied. The electrolyte for non-aqueous electrolyte batteries is no exception, and it has been proposed to suppress deterioration due to decomposition of the electrolyte on the surface of the active positive electrode and negative electrode by using an electrolytic coating with various durability improving agents. there is

For example, in Patent Document 1, as an electrolyte for a non-aqueous electrolyte battery that can exhibit a well-balanced effect of improving high-temperature storage characteristics at 70 ° C. or higher and reducing the amount of gas generated during high-temperature storage, (I ) a silane compound containing a group having a carbon-carbon unsaturated bond, (II) at least one selected from a cyclic sulfonic acid compound and a cyclic sulfate ester compound, (III) a non-aqueous organic solvent, and (IV) an electrolysis comprising a solute A liquid is disclosed. Further, it is disclosed that compounds represented by the following general formulas (II-1a) to (II-1f) are used as (II) above. It is disclosed that sultone, 1,3,2-dioxathiolane 2,2-dioxide, methylene methanedisulfonate and the like are preferably used.

Further, in Patent Document 2, in order to improve the high-temperature characteristics and life characteristics (cycle characteristics) of lithium batteries, a sulfonate ester system in which a cyclic sulfone group is bonded to a sulfonate group Including the compound as an additive in the electrolyte is disclosed.

International Publication No. 2017/138452 pamphlet U.S. Publication No. 2017/0271715 JP-A-10-139784

Journal of Organic Chemistry (1957), 22, 1200-2. Chemicke Zvesti (1964), 18, 21-7.

The electrolytic solution as described in Patent Document 1 tends to exhibit a well-balanced effect of improving the high-temperature storage characteristics of lithium batteries and reducing the amount of gas generated during high-temperature storage. 3-Propanesultone, 1,3-propenesultone, 1,3,2-dioxathiolane 2,2-dioxide, methylene methane disulfonate and their derivatives decompose during high temperature storage at 50°C or higher in the state of electrolyte. I found out the problem that there is a case to progress. Accordingly, an object of the present invention is to provide an electrolyte for non-aqueous electrolyte batteries with improved high-temperature storage stability (high-temperature storage characteristics), and a non-aqueous electrolyte battery including the electrolyte.

The present inventors have made intensive studies in view of such problems, and found that a non-aqueous organic solvent, a solute, a silicon compound having a specific structure containing a group having a carbon-carbon unsaturated bond, and a cyclic sulfur having a specific structure The present inventors have found that an electrolyte for non-aqueous electrolyte batteries containing a compound has improved high-temperature storage stability, leading to the present invention.

That is, the present invention
(I) a non-aqueous organic solvent,
(II) a solute that is an ionic salt;
(III) at least one additive selected from the group consisting of compounds represented by general formula (1) (hereinafter sometimes referred to as "silicon compound (1)"), and
(IV) for non-aqueous electrolyte batteries containing at least one additive selected from the group consisting of compounds represented by general formula (2) (hereinafter sometimes referred to as "cyclic sulfur compound (2)") It is an electrolytic solution (hereinafter sometimes simply referred to as "non-aqueous electrolytic solution" or "electrolytic solution").

Si(R ¹ ) _a (R ² ) _4-a (1)
[In general formula (1), each R ¹ independently represents a group having a carbon-carbon unsaturated bond.
R ² each independently represents a fluorine atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an allyl group having 3 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms. an aryl group having 6 to 15 carbon atoms, an allyloxy group having 3 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, and an aryloxy group having 6 to 15 carbon atoms. group, and these groups may have a fluorine atom and/or an oxygen atom. The phrase "having a fluorine atom" specifically refers to the above group in which a hydrogen atom is substituted with a fluorine atom. Further, "having an oxygen atom" specifically includes groups in which "--O--" (ether bond) is interposed between the carbon atoms of the above groups.
a is 2-4. ]

［一般式（２）中、Ｘは酸素原子、又はハロゲン原子に置換されていてもよいメチレン基であり、Ｙはリン原子、又は硫黄原子である。ｎはＹがリン原子の場合は０、硫黄原子の場合は１である。Ｒ^３、Ｒ^４はそれぞれ独立で、ハロゲン原子、ハロゲン原子に置換されていてもよい炭素数１～２０のアルキル基、ハロゲン原子に置換されていてもよい炭素数５～２０のシクロアルキル基、ハロゲン原子に置換されていてもよい炭素数２～２０のアルケニル基、ハロゲン原子に置換されていてもよい炭素数２～２０のアルキニル基、ハロゲン原子に置換されていてもよい炭素数６～４０のアリール基、ハロゲン原子に置換されていてもよい炭素数２～４０のヘテロアリール基、ハロゲン原子に置換されていてもよい炭素数１～２０のアルコキシ基、ハロゲン原子に置換されていてもよい炭素数５～２０のシクロアルコキシ基、ハロゲン原子に置換されていてもよい炭素数２～２０のアルケニルオキシ基、ハロゲン原子に置換されていてもよい炭素数２～２０のアルキニルオキシ基、ハロゲン原子に置換されていてもよい炭素数６～４０のアリールオキシ基、又は、ハロゲン原子に置換されていてもよい炭素数２～４０のヘテロアリールオキシ基であり、Ｙが硫黄原子の場合、Ｒ^４は存在しない。
Ｒ^５、Ｒ^６は、それぞれ独立して、水素原子、ハロゲン原子、ハロゲン原子に置換されていてもよい炭素数１～２０のアルキル基、ハロゲン原子に置換されていてもよい炭素数２～２０のアルケニル基、ハロゲン原子に置換されていてもよい炭素数２～２０のアルキニル基、ハロゲン原子に置換されていてもよい炭素数１～２０のアルコキシ基、ハロゲン原子に置換されていてもよい炭素数５～２０のシクロアルキル基、ハロゲン原子に置換されていてもよい炭素数６～４０のアリール基、又は、ハロゲン原子に置換されていてもよい炭素数２～４０のヘテロアリール基である。］

[In general formula (2), X is an oxygen atom or a methylene group optionally substituted with a halogen atom, and Y is a phosphorus atom or a sulfur atom. n is 0 when Y is a phosphorus atom and 1 when Y is a sulfur atom. R ³ and R ⁴ are each independently a halogen atom, an alkyl group having 1 to 20 carbon atoms optionally substituted by a halogen atom, a cycloalkyl group having 5 to 20 carbon atoms optionally substituted by a halogen atom, alkenyl groups having 2 to 20 carbon atoms which may be substituted by halogen atoms, alkynyl groups having 2 to 20 carbon atoms which may be substituted by halogen atoms, and 6 to 40 carbon atoms which may be substituted by halogen atoms aryl group, heteroaryl group having 2 to 40 carbon atoms optionally substituted by halogen atom, alkoxy group having 1 to 20 carbon atoms optionally substituted by halogen atom, optionally substituted by halogen atom cycloalkoxy groups having 5 to 20 carbon atoms, alkenyloxy groups having 2 to 20 carbon atoms which may be substituted by halogen atoms, alkynyloxy groups having 2 to 20 carbon atoms which may be substituted by halogen atoms, halogen atoms an aryloxy group having 6 to 40 carbon atoms which may be substituted with or a heteroaryloxy group having 2 to 40 carbon atoms which may be substituted with a halogen atom, and when Y is a sulfur atom, R ⁴ does not exist.
R ⁵ and R ⁶ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms optionally substituted by a halogen atom, or a 2 to 20 carbon atoms optionally substituted by a halogen atom. an alkenyl group, an alkynyl group having 2 to 20 carbon atoms which may be substituted by a halogen atom, an alkoxy group having 1 to 20 carbon atoms which may be substituted by a halogen atom, a carbon which may be substituted by a halogen atom A cycloalkyl group having 5 to 20 carbon atoms, an aryl group having 6 to 40 carbon atoms optionally substituted by a halogen atom, or a heteroaryl group having 2 to 40 carbon atoms optionally substituted by a halogen atom. ]

R ¹ above is preferably an ethenyl group.
In addition, the alkyl group for R ² includes methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, sec-pentyl group, 3-pentyl group, and is preferably selected from tert-pentyl groups,
Alkoxy groups include methoxy, ethoxy, butoxy, tert-butoxy, propoxy, isopropoxy, 2,2,2-trifluoroethoxy, 2,2,3,3-tetrafluoropropoxy, 1 , 1,1-trifluoroisopropoxy group and 1,1,1,3,3,3-hexafluoroisopropoxy group,
The allyl group is preferably a 2-propenyl group,
The alkynyl group is preferably an ethynyl group,
The aryl group is preferably selected from a phenyl group, a methylphenyl group, a tert-butylphenyl group, and a tert-amylphenyl group (hydrogen atoms in each aromatic ring may be substituted with fluorine atoms),
The allyloxy group is preferably a 2-propenyloxy group,
The alkynyloxy group is preferably propargyloxy group, and the aryloxy group is preferably selected from phenoxy group, methylphenoxy group, tert-butylphenoxy group and tert-amylphenoxy group (hydrogen atoms of each aromatic ring may be substituted with a fluorine atom).

In addition, the above (III) is preferably at least one selected from the group consisting of the following compounds (1-1) to (1-28), among which (1-1), (1 -2), (1-3), (1-4), (1-6), (1-7), (1-9), (1-10), (1-12), (1-15) ), (1-22), (1-23), (1-24), (1-25), (1-26), (1-27), and (1-28). At least one is more preferable from the viewpoint of ease of synthesis and stability of the compound.
Among them, (1-1), (1-2), (1-4), (1-6), (1-9), (1-12), (1-15), (1-22) ), and (1-24) is preferable from the viewpoint that the effect of improving high-temperature storage characteristics is more excellent, and (1-1), (1-9), (1-15), and (1-22) are particularly preferred.

It is preferable that a in the general formula (1) is 3 or 4 from the viewpoint of better recovery capacity after a high-temperature storage test.

The silicon compound (1), component (III), can be produced by various methods. For example, as described in Patent Document 3, Non-Patent Documents 1 and 2, a silicon compound having a silanol group or a hydrolyzable group and a carbon-carbon unsaturated bond-containing organometallic reagent are reacted to obtain It can be produced by a method for producing a carbon-carbon unsaturated bond-containing silicon compound such that the OH group or hydrolyzable group of the silanol group of is substituted with a carbon-carbon unsaturated bond group.

R ³ and R ⁴ in the general formula (2) are each independently a fluorine atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group and an n-pentyl group; , n-hexyl group, trifluoromethyl group, trifluoroethyl group, ethenyl group, 2-propenyl group, 2-propynyl group, phenyl group, naphthyl group, pentafluorophenyl group, methoxy group, ethoxy group, n-propoxy group , isopropoxy group, n-butoxy group, tert-butoxy group, n-pentyloxy group, n-hexyloxy group, trifluoromethoxy group, trifluoroethoxy group, ethenyloxy group, 2-propenyloxy group, 2-propynyloxy group, phenoxy group, naphthyloxy group, pentafluorophenoxy group, pyrrolyl group, and pyridinyl group, each independently fluorine atom, methyl group, trifluoromethyl group, ethenyl group, 2-pro It is particularly preferred to be selected from a penyl group, a phenyl group, and a phenoxy group from the viewpoint of ease of synthesis and high high-temperature storage properties.
R ⁵ and R ⁶ are each independently hydrogen atom, fluorine atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, trifluoromethyl group, tetrafluoroethyl; preferably selected from a group, phenyl group, naphthyl group, pentafluorophenyl group, pyrrolyl group, and pyridinyl group, and each independently selected from hydrogen atom and fluorine atom for ease of synthesis and high stability. It is particularly preferable from the viewpoint of durability.

In addition, the above (IV) is preferably at least one selected from the compounds represented by the following compounds (2-1) to (2-40),
Among them, (2-1), (2-2), (2-3), (2-5), (2-7), (2-8), (2-9), (2-11), ( 2-12), (2-14), (2-16), (2-19), (2-20), (2-21), (2-22), (2-23), (2- 24), (2-25), (2-27), (2-28), (2-29), (2-31), (2-32), (2-34), (2-38) , (2-39) and (2-40) are more preferable in terms of ease of synthesis and high high-temperature storage properties.
Among them, (2-1), (2-2), (2-5), (2-7), (2-9), (2-11), (2-14), (2-19) ), (2-20), (2-21), (2-22), (2-23), (2-25), (2-27), (2-29), (2-31), At least one selected from the group consisting of (2-34), (2-38), (2-39), and (2-40) is preferable from the viewpoint of superior high-temperature storage characteristics, ( 2-1), (2-5), (2-11), (2-19), (2-21), (2-22), (2-31), (2-38), and (2 -40) is particularly preferred.
stomach.

The cyclic sulfur compound (2), component (IV), can be produced by various methods. For example, the compound of formula (2-1) above can be obtained by hydrating 2,5-dihydrothiophene-1,1-dioxide as described in paragraphs [0107] to [0116] of Patent Document 2. It can be obtained by obtaining 3-hydroxytetrahydrothiophene-1,1-dioxide and reacting it with methanesulfonyl chloride in the presence of triethanolamine. Other cyclic sulfur compounds can also be obtained by the same production method by changing corresponding raw materials.

ADVANTAGE OF THE INVENTION According to this invention, the electrolyte solution for non-aqueous electrolyte batteries with which the high temperature storage stability was improved, and the non-aqueous electrolyte battery provided with the said electrolyte solution can be provided.

Configurations and combinations thereof in the following embodiments are examples, and configuration additions, omissions, substitutions, and other changes are possible without departing from the scope of the present invention. Moreover, the present invention is not limited by the embodiments, but only by the claims.

1. Electrolyte for non-aqueous electrolyte batteries The electrolyte for non-aqueous electrolyte batteries of the present invention is
(I) a non-aqueous organic solvent,
(II) a solute that is an ionic salt;
(III) at least one additive selected from the group consisting of compounds represented by the general formula (1); and
(IV) contains at least one additive selected from the group consisting of compounds represented by the general formula (2).

(I) Non-aqueous organic solvent The type of non-aqueous organic solvent used in the electrolyte for non-aqueous electrolyte batteries of the present invention is not particularly limited, and any non-aqueous organic solvent can be used. Specifically, ethyl methyl carbonate (hereinafter referred to as "EMC"), dimethyl carbonate (hereinafter referred to as "DMC"), diethyl carbonate (hereinafter referred to as "DEC"), methyl propyl carbonate, ethyl propyl carbonate, methyl butyl carbonate, 2,2,2-trifluoroethyl methyl carbonate, 2,2,2-trifluoroethyl ethyl carbonate, 2,2,2-trifluoroethyl propyl carbonate, bis(2,2,2-trifluoro ethyl) carbonate, 1,1,1,3,3,3-hexafluoro-1-propylmethyl carbonate, 1,1,1,3,3,3-hexafluoro-1-propylethyl carbonate, 1,1, 1,3,3,3-hexafluoro-1-propylpropyl carbonate, bis(1,1,1,3,3,3-hexafluoro-1-propyl) carbonate, ethylene carbonate (hereinafter referred to as "EC" ), propylene carbonate (hereinafter referred to as “PC”), butylene carbonate, fluoroethylene carbonate (hereinafter referred to as “FEC”), difluoroethylene carbonate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, 2- methyl fluoropropionate, ethyl 2-fluoropropionate, diethyl ether, dibutyl ether, diisopropyl ether, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, furan, tetrahydropyran, 1,3-dioxane, 1,4- At least one selected from the group consisting of dioxane, N,N-dimethylformamide, acetonitrile, propionitrile, dimethylsulfoxide, sulfolane, γ-butyrolactone, and γ-valerolactone is preferred.
In addition, ionic liquids and the like can also be mentioned, although they are in a different category from non-aqueous solvents.

Moreover, it is preferable that the non-aqueous organic solvent is at least one selected from the group consisting of cyclic carbonates and chain carbonates from the viewpoint of excellent cycle characteristics at high temperatures. Moreover, it is preferable that the non-aqueous organic solvent is at least one selected from the group consisting of esters, since the input/output characteristics at low temperatures are excellent.
Specific examples of the cyclic carbonate include EC, PC, butylene carbonate, FEC, etc. Among them, at least one selected from the group consisting of EC, PC, and FEC is preferable.
Specific examples of the chain carbonate include EMC, DMC, DEC, methylpropyl carbonate, ethylpropyl carbonate, 2,2,2-trifluoroethylmethyl carbonate, 2,2,2-trifluoroethylethyl carbonate, 1,1, 1,3,3,3-hexafluoro-1-propylmethyl carbonate and 1,1,1,3,3,3-hexafluoro-1-propylethyl carbonate, among others EMC, DMC, DEC, and at least one selected from the group consisting of methyl propyl carbonate.
Specific examples of the above ester include methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl 2-fluoropropionate, and ethyl 2-fluoropropionate.

(II) Solute For example, at least one cation selected from the group consisting of alkali metal ions and alkaline earth metal ions, hexafluorophosphate anion, tetrafluoroborate anion, trifluoromethanesulfonate anion, fluorosulfone acid anion, bis(trifluoromethanesulfonyl)imide anion, bis(fluorosulfonyl)imide anion, (trifluoromethanesulfonyl)(fluorosulfonyl)imide anion, bis(difluorophosphonyl)imide anion, (difluorophosphonyl)(fluorosulfonyl) An ionic salt comprising a pair of at least one anion selected from the group consisting of imide anions and (difluorophosphonyl)(trifluorosulfonyl)imide anions is preferred.

The cation of the ionic salt as the solute is lithium, sodium, potassium, or magnesium, and the anion is hexafluorophosphate anion, tetrafluoroborate anion, trifluoromethanesulfonate anion, or bis(trifluoromethanesulfonyl)imide. Anion, bis (fluorosulfonyl) imide anion, at least one selected from the group consisting of bis (difluorophosphonyl) imide anion, high solubility in the non-aqueous organic solvent and its electrochemical stability preferred from

The concentrations of these solutes are not particularly limited, but the lower limit is 0.5 mol/L or more, preferably 0.7 mol/L or more, more preferably 0.9 mol/L or more, and the upper limit is 2.5 mol/L. /L or less, preferably 2.2 mol/L or less, more preferably 2.0 mol/L or less. If it is less than 0.5 mol/L, the cycle characteristics and output characteristics of the non-aqueous electrolyte battery decrease due to the decrease in ionic conductivity. An increase in viscosity also reduces ionic conduction, which may deteriorate the cycle characteristics and output characteristics of the non-aqueous electrolyte battery. Moreover, these solutes may be used singly or in combination.

In the non-aqueous electrolyte, the concentration of (III) is preferably 0.01% by mass or more and 2.00% by mass or less with respect to 100% by mass as the total amount of (I) to (IV). If it is 0.01% by mass or more, the effect of improving the characteristics of the non-aqueous electrolyte battery is likely to be obtained, while if it is 2.00% by mass or less, a favorable effect of improving cycle characteristics is likely to be exhibited. The range is more preferably 0.04% by mass or more and 1.00% by mass or less, and still more preferably 0.08% by mass or more and 0.75% by mass or less.

In the non-aqueous electrolyte, the concentration of (IV) is preferably 0.01% by mass or more and 5.00% by mass or less with respect to 100% by mass as the total amount of (I) to (IV). If it is less than 0.01% by mass, it is difficult to sufficiently obtain the effect of improving cycle characteristics and the effect of scavenging hydrogen fluoride. Although extremely high, the initial capacity may be greatly reduced. The range is more preferably 0.10% by mass or more and 3.00% by mass or less, and still more preferably 0.30% by mass or more and 2.00% by mass or less.

Other Additives Additive components generally used in the electrolytic solution for non-aqueous electrolyte batteries of the present invention may be further added in an arbitrary ratio as long as they do not impair the gist of the present invention. Specific examples include cyclohexylbenzene, cyclohexylfluorobenzene, fluorobenzene (hereinafter sometimes referred to as FB), biphenyl, difluoroanisole, tert-butylbenzene, tert-amylbenzene, 2-fluorotoluene, 2-fluorobiphenyl , vinylene carbonate, dimethyl vinylene carbonate, vinyl ethylene carbonate, FEC, trans-difluoroethylene carbonate, methyl propargyl carbonate, ethyl propargyl carbonate, dipropargyl carbonate, maleic anhydride, succinic anhydride, methyl methanesulfonate, 1,6-di isocyanatohexane, tris(trimethylsilyl)borate, succinonitrile, (ethoxy)pentafluorocyclotriphosphazene, lithium difluorobis(oxalato)phosphate (hereinafter sometimes referred to as LDFBOP), difluorobis(oxalato)phosphate Sodium, potassium difluorobis(oxalato)phosphate, lithium difluorooxalatoborate (hereinafter sometimes referred to as LDFOB), sodium difluorooxalatoborate, potassium difluorooxalatoborate, lithium dioxalatoborate, sodium dioxalatoborate , potassium dioxalatoborate, lithium tetrafluorooxalate phosphate, sodium tetrafluorooxalate phosphate, potassium tetrafluorooxalate phosphate, lithium tris(oxalato)phosphate, lithium difluorophosphate (hereinafter referred to as LiPO ₂ F ₂ ), lithium ethylfluorophosphate, lithium fluorophosphate, ethenesulfonyl fluoride, trifluoromethanesulfonyl fluoride, methanesulfonyl fluoride, phenyl difluorophosphate, etc. Compounds with a protective effect are mentioned.
The content of the other additive in the electrolytic solution is preferably 0.01% by mass or more and 8.00% by mass or less.

In addition, when the content of the ionic salt mentioned as the solute in the electrolytic solution is less than 0.5 mol/L, which is the lower limit of the preferred concentration of the solute, the ionic salt is used as an “other additive” to form a negative electrode film. and positive electrode protection effect. In this case, the content in the electrolytic solution is preferably 0.01% by mass or more and 5.00% by mass. Examples of the ionic salt in this case include lithium trifluoromethanesulfonate, sodium trifluoromethanesulfonate, potassium trifluoromethanesulfonate, magnesium trifluoromethanesulfonate, and lithium fluoromethanesulfonate (hereinafter sometimes referred to as LiSO ₃ F). ), sodium fluorosulfonate, potassium fluorosulfonate, magnesium fluorosulfonate, lithium bis(trifluoromethanesulfonyl)imide, sodium bis(trifluoromethanesulfonyl)imide, potassium bis(trifluoromethanesulfonyl)imide, bis(trifluoromethanesulfonyl) ) imide magnesium, bis(fluorosulfonyl)imide lithium, bis(fluorosulfonyl)imide sodium, bis(fluorosulfonyl)imide potassium, bis(fluorosulfonyl)imide magnesium, (trifluoromethanesulfonyl)(fluorosulfonyl)imide lithium, (trifluoro romethanesulfonyl)(fluorosulfonyl)imide sodium, (trifluoromethanesulfonyl)(fluorosulfonyl)imide potassium, (trifluoromethanesulfonyl)(fluorosulfonyl)imide magnesium, bis(difluorophosphonyl)imide lithium, bis(difluorophosphonyl)imide sodium, bis(difluorophosphonyl)imide potassium, bis(difluorophosphonyl)imide magnesium, (difluorophosphonyl)(fluorosulfonyl)imide lithium, (difluorophosphonyl)(fluorosulfonyl)imide sodium, (difluorophosphonyl)( fluorosulfonyl)imide potassium, (difluorophosphonyl)(fluorosulfonyl)imide magnesium, (difluorophosphonyl)(trifluorosulfonyl)imide lithium, (difluorophosphonyl)(trifluorosulfonyl)imide sodium, (difluorophosphonyl)( trifluorosulfonyl)imide potassium, (difluorophosphonyl)(trifluorosulfonyl)imide magnesium, and the like.

Alkali metal salts other than the above solutes (lithium salt, sodium salt, potassium salt, magnesium salt) may be used as additives. Specific examples include carboxylates such as lithium acrylate, sodium acrylate, lithium methacrylate, and sodium methacrylate, and sulfate ester salts such as lithium methyl sulfate, sodium methyl sulfate, lithium ethyl sulfate, and sodium methyl sulfate. .

In addition, the electrolyte for non-aqueous electrolyte batteries of the present invention can also contain a polymer, and gels the electrolyte for non-aqueous electrolyte batteries as in the case of being used in a non-aqueous electrolyte battery called a polymer battery. It is also possible to quasi-solidify with an agent or a cross-linked polymer for use. Polymer solid electrolytes also include those containing non-aqueous organic solvents as plasticizers.

The polymer is not particularly limited as long as it is an aprotic polymer capable of dissolving the solute and the additive. Examples thereof include polymers having polyethylene oxide as a main chain or side chain, homopolymers or copolymers of polyvinylidene fluoride, methacrylic acid ester polymers, polyacrylonitrile, and the like. When adding a plasticizer to these polymers, an aprotic non-aqueous organic solvent is preferred among the above non-aqueous organic solvents.

1,3-propanesultone, 1,3-propenesultone, 1,3,2-dioxathiolane 2,2-dioxide, methylene methanedisulfonate, and derivatives thereof may be added to other compounds within a concentration range that does not impair the gist of the present invention. may be included as an additive. The concentration range is 0.01 to 1.0% by mass in the electrolytic solution and is less than the concentration of component (IV).

2. Non-aqueous electrolyte battery The non-aqueous electrolyte battery of the present invention comprises at least (a) the above electrolyte for non-aqueous electrolyte batteries, (b) a positive electrode, and (c) a negative electrode material containing lithium metal, lithium, and a negative electrode having at least one selected from the group consisting of negative electrode materials capable of occluding and releasing sodium, potassium, or magnesium. Furthermore, it is preferable to include (d) a separator, an outer package, and the like.

[(a) positive electrode]
(a) The positive electrode preferably contains at least one kind of oxide and/or polyanion compound as a positive electrode active material.

[Positive electrode active material]
In the case of a lithium ion secondary battery in which the cation in the non-aqueous electrolyte is mainly lithium, (a) the positive electrode active material constituting the positive electrode is not particularly limited as long as it is a material that can be charged and discharged. , for example, (A) a lithium-transition metal composite oxide containing at least one metal selected from nickel, manganese, and cobalt and having a layered structure, (B) a lithium-manganese composite oxide having a spinel structure, and (C) Those containing at least one selected from lithium-containing olivine-type phosphates and (D) lithium-excess layered transition metal oxides having a layered rocksalt structure.

((A) lithium transition metal composite oxide)
Positive electrode active material (A) Examples of lithium-transition metal composite oxides containing at least one metal selected from nickel, manganese, and cobalt and having a layered structure include lithium-cobalt composite oxides and lithium-nickel composite oxides. lithium-nickel-cobalt composite oxide, lithium-nickel-cobalt-aluminum composite oxide, lithium-cobalt-manganese composite oxide, lithium-nickel-manganese composite oxide, lithium-nickel-manganese-cobalt composite oxide etc. In addition, some of the transition metal atoms that are the main constituent of these lithium-transition metal composite oxides are You may use what substituted with other elements, such as.

Specific examples of lithium-cobalt composite oxides and lithium-nickel composite oxides include LiCoO ₂ , LiNiO ₂ and lithium cobalt oxide (LiCo _0.98 Mg 0.98 Mg 0.98 Mg 0.98) to which different elements such as Mg, Zr, Al and Ti are added _{. 01Zr0.01O2 , LiCo0.98Mg0.01Al0.01O2 , LiCo0.975Mg0.01Zr0.005Al0.01O2 , etc. ) , WO2014 / 034043} Lithium cobalt oxide or the like in which a rare earth compound is adhered to the surface described may also be used. Further, as described in Japanese Unexamined Patent Application Publication No. 2002-151077, it is also possible to use LiCoO ₂ particles whose particle surfaces are partly coated with aluminum oxide.

The lithium-nickel-cobalt composite oxide and the lithium-nickel-cobalt-aluminum composite oxide are represented by general formula [1-1].
Li _a Ni _1-bc Co _b M ¹ _c O ₂ [1-1]
In formula [1-1], M ¹ is at least one element selected from the group consisting of Al, Fe, Mg, Zr, Ti and B, a is 0.9 ≤ a ≤ 1.2, and b , c satisfy the conditions of 0.1≦b≦0.3 and 0≦c≦0.1.
These can be prepared, for example, according to the production method described in JP-A-2009-137834. Specifically, 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 _0.6 Co _0.3 Al _0.1 O ₂ and the like.

Specific examples of the lithium-cobalt-manganese composite oxide and the lithium-nickel-manganese composite oxide include LiNi _0.5 Mn _0.5 O ₂ and LiCo _0.5 Mn _0.5 O ₂ .

Lithium-nickel-manganese-cobalt composite oxides include lithium-containing composite oxides represented by the general formula [1-2].
_{LidNieMnfCogM2hO2 [} ^1-2 _{] _ _ _}
In formula [ ^1-2 ], M2 is at least one element selected from the group consisting of Al, Fe, Mg, Zr, Ti, B, and Sn, and d satisfies 0.9 ≤ d ≤ 1.2. , e, f, g, and h satisfy the conditions e+f+g+h=1, 0≦e≦0.7, 0≦f≦0.5, 0≦g≦0.5, and h≧0.
The lithium-nickel-manganese-cobalt composite oxide contains manganese within the range shown in the general formula [1-2] in order to improve structural stability and improve safety at high temperatures in lithium secondary batteries. More preferably, it further contains cobalt in the range represented by the general formula [1-2] in order to improve the high rate characteristics of the lithium ion secondary battery.
Specifically, for example, Li[Ni _1/3 Mn _1/3 Co _1/3 ]O ₂ and Li[Ni _0.45 Mn _0.35 Co _0.2 ] having a charge/discharge range at 4.3 V or higher _O2 , _Li [ _{Ni0.5Mn0.3Co0.2} ] _O2 , _Li [ _{Ni0.6Mn0.2Co0.2} ] _{O2 , Li [ Ni0.49Mn0.3Co 0.2Zr0.01} ] _{O2 , Li} [ _{Ni0.49Mn0.3Co0.2Mg0.01 ] O2 and} the like.

((B) Lithium manganese composite oxide having a spinel structure)
Positive electrode active material (B) Examples of lithium-manganese composite oxides having a spinel structure include spinel-type lithium-manganese composite oxides represented by general formula [1-3].
Li _j (Mn _2-k M ³ _k )O ₄ [1-3]
In formula [1-3], M3 is at least one metal element selected from the group consisting of Ni, Co, Fe, Mg, Cr, Cu, Al and Ti, and j is ^1.05≤j≤1 . 15, and k is 0≤k≤0.20.
Specifically, for example, LiMnO ₂ , LiMn ₂ O ₄ , LiMn _1.95 Al _0.05 O ₄ , LiMn _1.9 Al _0.1 O ₄ , LiMn _1.9 Ni _0.1 O ₄ , LiMn _{1 .5} Ni _0.5 O ₄ and the like.

((C) lithium-containing olivine-type phosphate)
Examples of the positive electrode active material (C) lithium-containing olivine-type phosphate include those represented by general formula [1-4].
LiFe _1-n M ⁴ _n PO ₄ [1-4]
In formula [ ^1-4 ], M4 is at least one selected from Co, Ni, Mn, Cu, Zn, Nb, Mg, Al, Ti, W, Zr and Cd, and n is 0 ≤ n ≤ 1.
Specifically, for example, _LiFePO4 , _LiCoPO4 , _LiNiPO4 , _LiMnPO4 , etc., can be mentioned, among which _LiFePO4 and/or _LiMnPO4 are preferred.

((D) lithium-excess layered transition metal oxide)
Positive electrode active material (D) Examples of the lithium-excess layered transition metal oxide having a layered rock salt structure include those represented by general formula [1-5].
xLiM ⁵ O _2. (1-x)Li ₂ M ⁶ O ₃ [1-5]
In formula [1-5], x is a number that satisfies 0<x< ¹ , M5 is at least one metal element having an average oxidation number of ³⁺ , and ^M6 is an average oxidation number. At least one metallic element whose number is 4 ⁺ . In formula [1-5], M ⁵ is preferably one kind of metal element selected from trivalent Mn, Ni, Co, Fe, V, and Cr, but equivalent amounts of divalent and tetravalent may have an average oxidation number of trivalent.
^In formula [1-5], M6 is preferably one or more metal elements selected from Mn, Zr and Ti. Specifically, 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 _{0.125Fe0.125Mn0.375O2} ] _.0.5 [ _Li2MnO3 ] _{, 0.45} [ _{LiNi0.375Co0.25Mn0.375O2 ] .0.10 [ Li 2} TiO ₃ ]·0.45[Li ₂ MnO ₃ ] and the like.
It is known that the positive electrode active material (D) represented by this general formula [1-5] exhibits high capacity when charged at a high voltage of 4.4 V (based on Li) or higher (for example, US Patent 7 , 135, 252).
These positive electrode active materials can be prepared, for example, according to the production methods described in JP-A-2008-270201, WO2013/118661, JP-A-2013-030284, and the like.

The positive electrode active material may contain at _{least one} selected from the above ₍ A) to (D) as a main component. Examples include transition element chalcogenides such as ₂ O ₅ , MoO ₃ and MoS ₂ , conductive polymers such as polyacetylene, polyparaphenylene, polyaniline, and polypyrrole, activated carbon, radical-generating polymers, and carbon materials.

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

[Positive electrode active material layer]
(a) The positive electrode has, for example, a positive electrode active material layer formed on at least one surface of a 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, if necessary, a conductive agent.
Binders include polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, styrene-butadiene rubber (SBR), carboxymethylcellulose, methylcellulose, cellulose acetate phthalate, hydroxypropylmethylcellulose, and polyvinyl alcohol. etc.
Examples of conductive agents that can be used include carbon materials such as acetylene black, ketjen black, furnace black, carbon fiber, graphite (granular graphite and scale-like graphite), and fluorinated graphite. For the positive electrode, it is preferable to use acetylene black or ketjen black with low crystallinity.

[(C) Negative electrode]
The negative electrode material is not particularly limited, but in the case of lithium batteries and lithium ion batteries, lithium metal, alloys and intermetallic compounds of lithium metal and other metals, various carbon materials (artificial graphite, natural graphite, etc.), metals Oxides, metal nitrides, tin (single substance), tin compounds, silicon (single substance), silicon compounds, activated carbon, conductive polymers and the like are used.

The carbon material includes, for example, graphitizable carbon, non-graphitizable carbon (hard carbon) having a (002) plane spacing of 0.37 nm or more, and graphite having a (002) plane spacing of 0.34 nm or less. and so on. More specifically, there are thermally decomposable carbon, cokes, glassy carbon fibers, baked organic polymer compounds, activated carbon, carbon blacks, and the like. Among them, cokes include pitch coke, needle coke, petroleum coke, and the like. A calcined organic polymer compound is a carbonized product obtained by calcining a phenol resin, a furan resin, or the like at an appropriate temperature. A carbon material is preferable because it has a very small change in crystal structure due to the absorption and desorption of lithium, so that a high energy density can be obtained and excellent cycle characteristics can be obtained. The shape of the carbon material may be fibrous, spherical, granular, or scaly. Amorphous carbon or a graphite material having a surface coated with amorphous carbon is more preferable because the reactivity between the surface of the material and the electrolytic solution is low.

(c) The negative electrode preferably contains at least one negative electrode active material.

[Negative electrode active material]
In the case of a lithium ion secondary battery in which the cation in the nonaqueous electrolyte is mainly lithium, (c) the negative electrode active material constituting the negative electrode is capable of doping and dedoping lithium ions. , for example, (E) a carbon material having a lattice plane (002 plane) d value of 0.340 nm or less in X-ray diffraction, (F) a carbon material having a lattice plane (002 plane) d value of more than 0.340 nm in X-ray diffraction Materials, (G) one or more metal oxides selected from Si, Sn, and Al, (H) one or more metals selected from Si, Sn, and Al, alloys containing these metals, or these metals or alloys Those containing at least one selected from alloys with lithium and (I) lithium titanium oxides can be mentioned. One of these negative electrode active materials can be used alone, or two or more of them can be used in combination.

((E) a carbon material having a lattice plane (002 plane) d value of 0.340 nm or less in X-ray diffraction)
Negative electrode active material (E) Examples of carbon materials having a lattice plane (002 plane) d value of 0.340 nm or less in X-ray diffraction include pyrolytic carbons and cokes (e.g., pitch coke, needle coke, petroleum coke, etc.). , graphites, organic polymer compound calcined bodies (for example, phenol resin, furan resin, etc. calcined at an appropriate temperature and carbonized), carbon fibers, activated carbon, etc. These may be graphitized. The carbon material has a lattice spacing (d002) between (002) planes of 0.340 nm or less as measured by an X-ray diffraction method, and is graphite or graphite having a true density of 1.70 g/cm ³ or more. Highly crystalline carbon materials with similar properties are preferred.

((F) a carbon material in which the d value of the lattice plane (002 plane) in X-ray diffraction exceeds 0.340 nm)
Negative electrode active material (F) Carbon materials in which the d value of the lattice plane (002 plane) in X-ray diffraction exceeds 0.340 nm include amorphous carbon, which is heat-treated at a high temperature of 2000 ° C. or higher. is also a carbon material in which the stacking order hardly changes. For example, non-graphitizable carbon (hard carbon), mesocarbon microbeads (MCMB) fired at 1500° C. or less, mesopasbitch carbon fiber (MCF), and the like are exemplified. Carbotron (registered trademark) P manufactured by Kureha Corporation is a typical example.

((G) one or more metal oxides selected from Si, Sn and Al)
Negative electrode active material (G) The oxide of one or more metals selected from Si, Sn, and Al includes, for example, silicon oxide and tin oxide, which can be doped/dedoped with lithium ions.
There is _SiOx , etc., which has a structure in which ultrafine particles of Si are dispersed in _SiO2 . When this material is used as a negative electrode active material, charging and discharging are performed smoothly because the Si that reacts with Li is ultrafine particles, while the SiO _x particles having the above structure themselves have a small surface area, so the negative electrode active material layer The composition (paste) for forming the coating property and the adhesion of the negative electrode mixture layer to the current collector are also good.
Since SiO _x undergoes a large volume change during charging and discharging, by using SiO _x and graphite of the negative electrode active material (E) in a specific ratio as the negative electrode active material, the capacity can be increased and good charge-discharge cycle characteristics can be obtained. can be compatible with

((H) One or more metals selected from Si, Sn, and Al, alloys containing these metals, or alloys of these metals or alloys and lithium)
Negative electrode active material (H) One or more metals selected from Si, Sn, and Al, alloys containing these metals, or alloys of these metals or alloys and lithium include, for example, metals such as silicon, tin, and aluminum, and silicon alloys , tin alloys, aluminum alloys, etc., and materials obtained by alloying these metals or alloys with lithium during charging and discharging can also be used.
Preferred specific examples thereof include simple metals such as silicon (Si) and tin (Sn) (for example, in powder form) and metal alloys described in WO2004/100293 and JP-A-2008-016424. , a compound containing the metal, an alloy containing tin (Sn) and cobalt (Co) in the metal, and the like. When the metal is used for the electrode, it is preferable because high charge capacity can be exhibited and the expansion/contraction of the volume due to charge/discharge is relatively small. In addition, these metals are known to exhibit high charge capacity when used for the negative electrode of a lithium ion secondary battery because they are alloyed with Li during charging, which is also preferable.
Furthermore, a negative electrode active material formed of silicon pillars with a submicron diameter, a negative electrode active material made of fibers composed of silicon, and the like, which are described in WO2004/042851, WO2007/083155, etc., for example, may also be used. .

((I) lithium titanium oxide)
Examples of the negative electrode active material (I) lithium titanium oxide include lithium titanate having a spinel structure and lithium titanate having a ramsdellite structure.
Lithium titanate having a spinel structure includes, for example, Li _4+α Ti ₅ O ₁₂ (α changes within the range of 0≦α≦3 depending on the charge/discharge reaction). Lithium titanate having a ramsdellite structure includes, for example, Li _2+β Ti ₃ O ₇ (β varies within the range of 0≦β≦3 depending on the charge/discharge reaction). These negative electrode active materials can be prepared, for example, according to the production methods described in JP-A-2007-018883, JP-A-2009-176752, and the like.
For example, in the case of a sodium ion secondary battery in which the cation in the non-aqueous electrolyte is mainly sodium, hard carbon, oxides such as TiO ₂ , V ₂ O ₅ and MoO ₃ are used as the negative electrode active material. For example, in the case of a sodium ion secondary battery in which the cation in the non-aqueous electrolyte is mainly sodium, sodium-containing transition metal composite oxides such as NaFeO ₂ , NaCrO ₂ , NaNiO ₂ , NaMnO ₂ and NaCoO ₂ as the positive electrode active material, A mixture of a plurality of transition metals such as Fe, Cr, Ni, Mn, and Co in those sodium-containing transition metal composite oxides, and a part of the transition metals in these sodium-containing transition metal composite oxides other than other transition metals transition metal phosphate _compounds such as _Na2FeP2O7 and _{NaCo3 ( PO4} ) _{2P2O7 ; sulfides} such as _TiS2 and _FeS2 ; Conductive polymers such as phenylene, polyaniline, and polypyrrole, activated carbon, radical-generating polymers, and carbon materials are used.

[Negative electrode current collector]
(c) The negative electrode has a negative electrode current collector. As the negative electrode current collector, for example, copper, stainless steel, nickel, titanium, alloys thereof, or the like can be used.

[Negative electrode active material layer]
(c) For the negative electrode, for example, a negative electrode active material layer is formed on at least one surface of a negative electrode current collector. The negative electrode active material layer is composed of, for example, the negative electrode active material described above, a binder, and, if necessary, a conductive agent.
Binders include polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, styrene-butadiene rubber (SBR), carboxymethylcellulose, methylcellulose, cellulose acetate phthalate, hydroxypropylmethylcellulose, and polyvinyl alcohol. etc.
Examples of conductive agents that can be used include carbon materials such as acetylene black, ketjen black, furnace black, carbon fiber, graphite (granular graphite and scale-like graphite), and fluorinated graphite.

[Method for producing electrodes ((a) positive electrode and (c) negative electrode)]
The electrode is obtained, for example, by dispersing and kneading an active material, a binder, and, if necessary, a conductive agent in a predetermined compounding amount in a solvent such as N-methyl-2-pyrrolidone (NMP) or water. The paste can be applied to a current collector and dried to form an active material layer. The obtained electrode is preferably compressed by a method such as a roll press to adjust the density of the electrode to an appropriate one.

[(d) Separator]
The above non-aqueous electrolyte battery can be provided with (d) a separator. As a separator for preventing contact between (a) the positive electrode and (c) the negative electrode, a nonwoven fabric or porous sheet made of polyolefin such as polypropylene or polyethylene, cellulose, paper, glass fiber, or the like is used. These films are preferably microporous so that the electrolytic solution permeates them and the ions easily permeate them.
Examples of the polyolefin separator include a membrane such as a microporous polymer film such as a porous polyolefin film that electrically insulates the positive electrode and the negative electrode and is permeable to lithium ions. As a specific example of the porous polyolefin film, for example, a porous polyethylene film may be used alone, or a porous polyethylene film and a porous polypropylene film may be laminated to form a multilayer film. Moreover, the film etc. which combined the porous polyethylene film and the polypropylene film are mentioned.

[Exterior body]
In constructing the non-aqueous electrolyte battery, as the exterior body of the non-aqueous electrolyte battery, for example, a coin-shaped, cylindrical, square-shaped metal can, or a laminate exterior body can be used. Metal can materials include, for example, nickel-plated steel plates, stainless steel plates, nickel-plated stainless steel plates, aluminum or its alloys, nickel, and titanium.
As the laminated exterior body, for example, an aluminum laminated film, a SUS laminated film, a silica-coated polypropylene or polyethylene laminated film, or the like can be used.

The configuration of the non-aqueous electrolyte battery according to the present embodiment is not particularly limited. can be configured. The shape of the non-aqueous electrolyte battery is not particularly limited, but an electrochemical device having a shape such as a coin shape, a cylindrical shape, a rectangular shape, or an aluminum laminate sheet shape can be assembled from the above components.

The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these descriptions.

[Preparation of NCM811 positive electrode]
91.0% by mass of LiNi _0.8 Mn _0.1 Co _0.1 O ₂ powder was mixed with 4.5% by mass of polyvinylidene fluoride (PVDF) as a binder and 4.5% by mass of acetylene black as a conductive material. -2-Pyrrolidone (hereinafter referred to as NMP) was added to prepare a positive electrode mixture paste. This paste was applied to both sides of an aluminum foil (A1085), dried and pressed, and then punched out into a size of 4×5 cm to obtain an NCM811 positive electrode for testing.

[Preparation of silicon-containing graphite negative electrode]
85% by mass of artificial graphite powder, 7% by mass of nanosilicon, 3% by mass of conductive material (HS-100), 2% by mass of carbon nanotube (VGCF), 2% by mass of styrene-butadiene rubber, 1% by mass of sodium carboxymethylcellulose and water were mixed to prepare a negative electrode mixture paste. This paste was applied to one side of a copper foil, dried and pressed, and then punched out into a size of 4×5 cm to obtain a silicon-containing graphite negative electrode for testing.

[Preparation of LiPF ₆ solution]
EC, FEC, EMC, and DMC were mixed in a volume ratio of 2:1:3:4, respectively, in a glove box with a dew point of −60° C. or lower. After that, while keeping the internal temperature at 40° C. or lower, LiPF ₆ was added in an amount to give a concentration of 1.0 M, and was completely dissolved by stirring to obtain a LiPF ₆ solution.

[Preparation of electrolytic solution]
A silicon compound (1-2) corresponding to 0.1 mass % of the LiPF ₆ solution was added and dissolved by stirring for 1 hour. This was designated as non-aqueous electrolyte 1-(1-2)-0.1. Next, a silicon compound (1-2) corresponding to 0.1% by mass and a cyclic sulfur compound (2-1) corresponding to 1.0% by mass were added to the LiPF ₆ solution and stirred for 1 hour. Dissolved. This was designated as non-aqueous electrolyte 1-(1-2)-0.1-(2-1)-1.0. Hereinafter, similarly, as shown in Tables 1 and 2, the components (III) and (IV) are added so that the concentrations shown in Tables 1 and 2 are obtained, and the respective non-aqueous electrolysis is performed by stirring and dissolving. I got the liquid.
In the table, PRS means 1,3-propene sultone and MMDS means methylene methane disulfonate.

Similarly, as shown in Table 3,
Components (III), (IV), and other solutes or additive components were added to the LiPF ₆ solution so as to have the concentrations shown in Table 3, and dissolved by stirring to obtain the respective non-aqueous electrolytes. got

[Evaluation of 50 ° C storage stability of electrolyte solution]
Add 150 mL of each non-aqueous electrolyte to a stainless steel bottle with a capacity of 250 mL (the body and cap are made of SUS304 and acid-cleaned, and the packing material is tetrafluoroethylene-purple vinyl ether copolymer). Stored in a constant temperature bath. After one month, it was taken out from the constant temperature bath and allowed to stand at room temperature for 24 hours, and the Hazen color number (APHA) was measured using a Hazen meter (TZ6000, manufactured by Nippon Denshoku Industries).

[Preparation of non-aqueous electrolyte battery]
In an argon atmosphere with a dew point of −50° C. or less, after welding the terminal to the above-mentioned NCM811 positive electrode, both sides of it are sandwiched between two polyethylene separators (5 × 6 cm), and the terminal is welded in advance on the outside of the silicon-containing graphite negative electrode. The two sheets were sandwiched so that the surface of the negative electrode active material faced the surface of the positive electrode active material. Then, they are placed in an aluminum laminate bag with an opening on one side, and after vacuum injection of a non-aqueous electrolyte, the opening is thermally sealed to obtain an aluminum laminate according to the example and the comparative example. A battery of the following type was produced. The non-aqueous electrolytes listed in Tables 1 to 3 were used. The non-aqueous electrolyte used was a new one (which had not undergone the above-mentioned "evaluation of storage stability at 50°C of electrolyte").

[Initial charge/discharge]
The battery thus assembled had a capacity of 75 mAh as standardized by the weight of the positive electrode active material. The battery was placed in a constant temperature bath at 25° C. and connected to a charging/discharging device in that state. The battery was charged to 4.2 V at a charging rate of 0.2 C (current value for full charge in 5 hours). After maintaining 4.2V for 1 hour, the battery was discharged to 3.0V at a discharge rate of 0.2C. This was regarded as one charge/discharge cycle, and a total of 3 cycles of charge/discharge were performed to stabilize the battery.

[Measurement of recovery capacity after storage at 70°C for 2 weeks]
Next, after charging to 4.2 V at a charging rate of 0.2 C, the cell was removed from the charging/discharging apparatus and placed in a constant temperature bath at 70°C. Two weeks later, the cell was taken out from the constant temperature bath, allowed to stand at room temperature for 24 hours, and then discharged to 3.0 V at a discharge rate of 0.2C. Subsequently, the battery was charged to 4.2 V at a charge rate of 0.2 C and discharged to 3.0 V at a discharge rate of 0.2 C. The capacity obtained by this discharge was taken as the recovery capacity.

Tables 4 and 5 show the evaluation results (APHA) of the storage stability at 50° C. of the above electrolytic solutions and the measurement results of the recovery capacities of cells produced using electrolytic solutions having the same composition. The recovery capacity is 100 for each cell using an electrolytic solution that does not contain a cyclic sulfur compound (eg Comparative Examples 1-1, 1-3, 1-5, etc.), and the cyclic sulfur compound (2), PRS, or A relative value for a cell using an electrolyte containing MMDS is shown.

When 1.0% by mass of PRS is added to the silicon compound (1-2), the recovery capacity of the cell is improved by 10 to 23%, but the APHA after storage at 50 ° C. is 103 in the range of 38 to 55. ~120 (comparison between Comparative Examples 1-1 and 1-2, between Comparative Examples 1-3 and 1-4, and between Comparative Examples 1-5 and 1-6). An increase in APHA means an increase in coloration of the liquid, which is considered to be due to decomposition and deterioration of components contained in the electrolyte. As the amount of silicon compound (1-2) added increases from 0.1% by mass, 0.25% by mass, to 0.5% by mass, the value of APHA slightly increases (Comparative Example 1- 1, 1-3, and 1-5), and the addition of PRS significantly increased the decomposition, indicating that the decomposition of PRS is more significant than that of the silicon compound (1-2). When 1.0% by mass of the cyclic sulfur compound (2-1) was added instead of PRS, the recovery capacity was improved with almost no increase in APHA (Comparative Example 1-1 and Example 1 -1, Comparison between Comparative Example 1-3 and Example 1-3, Comparative Example 1-5 and Example 1-9), the cyclic sulfur compound (2-1) was not decomposed even after storage at 50 ° C. I understand. Also, by replacing the cyclic sulfur compound (2-1) with (2-5), (2-11), (2-19), and (2-31), the recovery capacity can be improved without increasing APHA. (Comparison between Comparative Example 1-3 and Examples 1-5, 1-6, 1-7 and 1-8).

Even when silicon compounds (1-9), (1-22), (1-4), (1-15), and (1-28) were used, the addition of PRS significantly increased APHA. In contrast (Comparative Examples 2-3 and 2-4, Comparative Examples 3-3 and 3-4, Comparative Examples 5-1 and 5-2, Comparative Examples 7-1 and 7-2, Comparison of Comparative Example 9-1 and Comparative Example 9-2), as cyclic sulfur compounds (2-1), (2-5), (2-11), (2-21), (2-22), ( 2-31), (2-38), and (2-40) were able to improve the recovery capacity without significantly increasing APHA (Examples 2-3 and 2-5). ~ 2-8, Examples 3-3, Examples 3-5 to 3-8, Examples 5-1 to 5-2, Examples 7-1 to 7-2, Examples 9-1 to 9-2 ).

MMDS is even less stable than PRS, and when 1% by mass of MMDS is added to silicon compounds (1-1), (1-12), and (1-24), APHA increases more than when PRS is added. was observed (Comparative Examples 4-1 and 4-2, Comparative Examples 6-1 and 6-2, and Comparative Examples 8-1 and 8-2). However, here too, cyclic sulfur compounds (2-1), (2-5), (2-11), (2-19), (2-22), and (2-38) can be used instead of MMDS. , the recovery capacity could be improved without a significant increase in APHA (Examples 4-1 and 4-2, Examples 6-1 and 6-2, and Examples 8-1 and 8-2).

Evaluation of 50° C. Storage Stability of an Electrolyte Solution in which Any of LiSO ₃ F, LDFOB, LiPO ₂ F ₂ and LDFBOP is Added as Other Components to Components (I), (II), (III) and (IV) Table 6 shows the results (APHA) and the measurement results of the recovery capacities of the cells fabricated using the electrolytic solution of the same composition. The recovery capacity is shown as a relative value when the value of the cell using the electrolyte containing no other components is set to 100 for each.

Here, silicon compounds (1-1), (1-2), (1-4), (1-9), (1-12), (1-15), (1-22), (1-24 ), (1-28) and cyclic sulfur compounds (2-1), (2-5), (2-11), (2-21), (2-22) as other components Any addition of LiSO ₃ F, LDFOB, LiPO ₂ F ₂ , or LDFBOP was able to achieve further improvements in recovery capacity without significantly affecting APHA.

Claims (17)

(I) a non-aqueous organic solvent,
(II) a solute that is an ionic salt;
(III) at least one additive selected from the group consisting of compounds represented by general formula (1), and
(IV) Electrolyte solution for non-aqueous electrolyte batteries containing at least one additive selected from the group consisting of compounds represented by formula (2).
Si(R ¹ ) _a (R ² ) _4-a (1)
[In general formula (1), each R ¹ independently represents a group having a carbon-carbon unsaturated bond.
R ² each independently represents a fluorine atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an allyl group having 3 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms. an aryl group having 6 to 15 carbon atoms, an allyloxy group having 3 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, and an aryloxy group having 6 to 15 carbon atoms. group, and these groups may have a fluorine atom and/or an oxygen atom. The phrase "having a fluorine atom" specifically refers to the above group in which a hydrogen atom is substituted with a fluorine atom. Further, "having an oxygen atom" specifically includes groups in which "--O--" (ether bond) is interposed between the carbon atoms of the above groups.
a is 2-4. ]

[In general formula (2), X is an oxygen atom or a methylene group optionally substituted with a halogen atom, and Y is a phosphorus atom or a sulfur atom. n is 0 when Y is a phosphorus atom and 1 when Y is a sulfur atom. R ³ and R ⁴ are each independently a halogen atom, an alkyl group having 1 to 20 carbon atoms optionally substituted by a halogen atom, a cycloalkyl group having 5 to 20 carbon atoms optionally substituted by a halogen atom, alkenyl groups having 2 to 20 carbon atoms which may be substituted by halogen atoms, alkynyl groups having 2 to 20 carbon atoms which may be substituted by halogen atoms, and 6 to 40 carbon atoms which may be substituted by halogen atoms aryl group, heteroaryl group having 2 to 40 carbon atoms optionally substituted by halogen atom, alkoxy group having 1 to 20 carbon atoms optionally substituted by halogen atom, optionally substituted by halogen atom cycloalkoxy groups having 5 to 20 carbon atoms, alkenyloxy groups having 2 to 20 carbon atoms which may be substituted by halogen atoms, alkynyloxy groups having 2 to 20 carbon atoms which may be substituted by halogen atoms, halogen atoms an aryloxy group having 6 to 40 carbon atoms which may be substituted with or a heteroaryloxy group having 2 to 40 carbon atoms which may be substituted with a halogen atom, and when Y is a sulfur atom, R ⁴ does not exist.
R ⁵ and R ⁶ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms optionally substituted by a halogen atom, or a 2 to 20 carbon atoms optionally substituted by a halogen atom. an alkenyl group, an alkynyl group having 2 to 20 carbon atoms which may be substituted by a halogen atom, an alkoxy group having 1 to 20 carbon atoms which may be substituted by a halogen atom, a carbon which may be substituted by a halogen atom A cycloalkyl group having 5 to 20 carbon atoms, an aryl group having 6 to 40 carbon atoms optionally substituted by a halogen atom, or a heteroaryl group having 2 to 40 carbon atoms optionally substituted by a halogen atom. ] The electrolytic solution for non-aqueous electrolyte batteries according to claim 1, wherein said ^R1 is an ethenyl group. of said R ² ,
alkyl group selected from methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, sec-pentyl group, 3-pentyl group, and tert-pentyl group; is a group that is
alkoxy group is methoxy group, ethoxy group, butoxy group, tert-butoxy group, propoxy group, isopropoxy group, 2,2,2-trifluoroethoxy group, 2,2,3,3-tetrafluoropropoxy group, 1 , 1,1-trifluoroisopropoxy group and 1,1,1,3,3,3-hexafluoroisopropoxy group,
the allyl group is a 2-propenyl group,
the alkynyl group is an ethynyl group,
the aryl group is a group selected from a phenyl group, a methylphenyl group, a tert-butylphenyl group, and a tert-amylphenyl group (a hydrogen atom of each aromatic ring may be substituted with a fluorine atom);
the allyloxy group is a 2-propenyloxy group,
the alkynyloxy group is a propargyloxy group,
the aryloxy group is a group selected from a phenoxy group, a methylphenoxy group, a tert-butylphenoxy group, and a tert-amylphenoxy group (a hydrogen atom of each aromatic ring may be substituted with a fluorine atom); The electrolyte for non-aqueous electrolyte batteries according to claim 1 or 2. 4. The electrolyte for non-aqueous electrolyte batteries according to any one of claims 1 to 3, wherein a in the general formula (1) is 3 or 4. The electrolyte solution for non-aqueous electrolyte batteries according to any one of claims 1 to 4, wherein (III) is at least one member selected from the group consisting of the following (1-1) to (1-28).

The (III) is the (1-1), (1-2), (1-3), (1-4), (1-6), (1-7), (1-9), ( 1-10), (1-12), (1-15), (1-22), (1-23), (1-24), (1-25), (1-26), (1- 27), and at least one selected from the group consisting of (1-28). The (III) is the (1-1), (1-2), (1-4), (1-6) (1-9), (1-12), (1-15), (1 -22) and (1-24). R ³ and R ⁴ are each independently fluorine atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, trifluoromethyl group, trifluoroethyl group, ethenyl group, 2-propenyl group, 2-propynyl group, phenyl group, naphthyl group, pentafluorophenyl group, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n -butoxy group, tert-butoxy group, n-pentyloxy group, n-hexyloxy group, trifluoromethoxy group, trifluoroethoxy group, ethenyloxy group, 2-propenyloxy group, 2-propynyloxy group, phenoxy group, naphthyl The electrolyte for non-aqueous electrolyte batteries according to any one of claims 1 to 7, which is selected from an oxy group, a pentafluorophenoxy group, a pyrrolyl group, and a pyridinyl group. 8. Any one of claims 1 to 7, wherein said R ³ and R ⁴ are each independently selected from a fluorine atom, a methyl group, a trifluoromethyl group, an ethenyl group, a 2-propenyl group, a phenyl group and a phenoxy group. The electrolytic solution for a non-aqueous electrolyte battery according to claim 1. R ⁵ and R ⁶ each independently represent a hydrogen atom, fluorine atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, trifluoromethyl group, tetrafluoro The electrolyte for non-aqueous electrolyte batteries according to any one of claims 1 to 9, which is selected from an ethyl group, a phenyl group, a naphthyl group, a pentafluorophenyl group, a pyrrolyl group, and a pyridinyl group. 10. The electrolyte for non-aqueous electrolyte batteries according to claim 1, wherein said R ⁵ and R ⁶ are each independently selected from a hydrogen atom and a fluorine atom. The electrolyte for non-aqueous electrolyte batteries according to any one of claims 1 to 11, wherein said non-aqueous organic solvent contains at least one selected from the group consisting of cyclic carbonates and chain carbonates. The cyclic carbonate is at least one selected from the group consisting of ethylene carbonate, propylene carbonate, and fluoroethylene carbonate, and the chain carbonate is the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, and methyl propyl carbonate. The electrolytic solution for a non-aqueous electrolytic battery according to claim 12, which is at least one selected from. The solute comprises at least one cation selected from the group consisting of alkali metal ions and alkaline earth metal ions, hexafluorophosphate anion, tetrafluoroborate anion, trifluoromethanesulfonate anion, and bis(trifluoromethane). 14. The electrolyte for non-aqueous electrolyte batteries according to any one of claims 1 to 13, which is an ionic salt paired with at least one anion selected from the group consisting of sulfonyl)imide anions. The cation of the solute is lithium, sodium, potassium, or magnesium, and the anion is selected from the group consisting of hexafluorophosphate anion, tetrafluoroborate anion, trifluoromethanesulfonate anion, and bis(trifluoromethanesulfonyl)imide anion. The electrolytic solution for a non-aqueous electrolyte battery according to claim 14, which is at least one kind. The non-aqueous electrolyte battery according to any one of claims 1 to 15, wherein the concentration of (III) is 0.01 to 2.00% by mass with respect to 100% by mass of the total amount of (I) to (IV). Electrolyte for At least, the electrolyte for non-aqueous electrolyte batteries according to any one of claims 1 to 16,
a positive electrode;
A non-aqueous electrolyte battery, comprising: a negative electrode material containing lithium metal; and a negative electrode having at least one selected from the group consisting of negative electrode materials capable of intercalating and deintercalating lithium, sodium, potassium, or magnesium.