JP2021114435A - Nonaqueous electrolyte additive, and nonaqueous electrolyte and nonaqueous electrolyte secondary battery that contain the same - Google Patents

Abstract

To provide a nonaqueous electrolyte additive that can improve the cycle characteristic and the rate characteristic of a nonaqueous electrolyte secondary battery.SOLUTION: The nonaqueous electrolyte additive comprises a compound having a structure represented by general formula (1) in a molecule. (In the formula, R1 to R3 each independently represent a C1-6 monovalent hydrocarbon group; R4 represents a C1-8 divalent hydrocarbon group; and the symbol * represents a bond; where some hydrogen atoms in the mono- or divalent hydrocarbon group may be substituted with hydroxy groups.)SELECTED DRAWING: None

Description

The present invention relates to a non-aqueous electrolyte additive, a non-aqueous electrolyte containing the same, and a non-aqueous electrolyte secondary battery. Regarding non-aqueous electrolyte secondary batteries.

With the spread of portable electronic devices such as portable personal computers, handy video cameras, and information terminals in recent years, non-aqueous electrolyte secondary batteries having high voltage and high energy density have come to be widely used as a power source. In addition, from the viewpoint of environmental problems, electric vehicles and hybrid vehicles that use electric power as a part of power are being put into practical use.

The non-aqueous electrolyte secondary battery is composed of members such as a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte. The positive electrode and the negative electrode usually include a current collector and an electrode mixture layer formed on the current collector. The electrode mixture layer is formed by applying, for example, an electrode active material capable of occluding / releasing lithium ions and a slurry composition in which a binder or the like is dispersed in a dispersion medium on a current collector and drying the mixture.

As a method for improving the performance of the secondary battery, a method of adding an additive to the non-aqueous electrolyte has been proposed because the treatment method is simple. For example, by adding vinylene carbonate (see, for example, Patent Document 1), methylphenyl carbonate (see, for example, Patent Document 2), sulfonamide compound (Patent Documents 3 and 4) and the like to a non-aqueous electrolyte, cycle characteristics It is said that battery performance such as charge / discharge capacity and storage characteristics at high temperatures can be improved.

Japanese Unexamined Patent Publication No. 2000-1238667 Japanese Unexamined Patent Publication No. 08-293323 Japanese Unexamined Patent Publication No. 2004-259697 Japanese Unexamined Patent Publication No. 2013-93242

Many electrolyte additives have been developed to improve battery performance. It is considered that the electrolyte additive forms a film called a SEI film (Solid Electrolyte Interface) on the electrode surface with the charge / discharge reaction. This coating provides resistance to the ingress and egress of ions responsible for electrical conduction, especially during high-speed charging and discharging. Therefore, a non-aqueous electrolyte secondary battery that not only has excellent cycle characteristics (maintenance performance of battery capacity after repeated charging and discharging) but also has excellent rate characteristics with little decrease in capacity even after charging and discharging in a short time. I was asked.

Therefore, an object of the present invention is to provide a non-aqueous electrolyte additive capable of improving the cycle characteristics and rate characteristics of a non-aqueous electrolyte secondary battery.

As a result of diligent studies, the present inventors have achieved the above object by using a silyl ester compound having a specific structure, specifically, a silyl ester compound containing a nitrogen atom in the molecule as a non-aqueous electrolyte additive. We have found that the above can be achieved, and have completed the present invention.

That is, the present invention is a non-aqueous electrolyte additive composed of a compound having a structure represented by the general formula (1) in the molecule.

(In the formula, R ^{1 to} R ³ independently represent a monovalent hydrocarbon group having 1 to 6 carbon atoms, and R ⁴ represents a divalent hydrocarbon group having 1 to 8 carbon atoms. Represented, * represents a bond. However, some hydrogen atoms of a monovalent or divalent hydrocarbon group may be substituted with a hydroxyl group.)

In the present invention, the compound is preferably a reaction product of trialkylchlorosilane and a carboxylic acid compound.

In the present invention, the compound is preferably selected from the group of compounds represented by the general formulas (2) to (7).

(In the formula, R ^{5 to} R ⁷ each independently represent the following Z, a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms, but at least one of ^{R 5 to} R ^{7 is} It represents Z below. However, two of R ^{5 to} R ⁷ may be bonded to each other to form a ring, and hetero atoms (oxygen atom, nitrogen atom and sulfur atom) are contained in a monovalent hydrocarbon group. It may be contained, and some hydrogen atoms of the monovalent hydrocarbon group may be substituted with a hydroxyl group.)

(In the formula, R ^{8 to} R ¹⁰ each independently represent a monovalent hydrocarbon group having 1 to 6 carbon atoms, * represents a bond, and R ¹¹ represents a carbon atom number 1 to 8 Represents the divalent hydrocarbon group of, or is a direct bond between the carbon atom of the carbonyl group and the bond.)

(In the formula, R ^{12 to} R ¹⁵ each independently represent the above-mentioned Z, hydrogen atom or monovalent hydrocarbon group having 1 to 8 carbon atoms, but at least one of ^{R 12 to} R ^{15 is} Representing Z above, R ¹⁶ represents a divalent hydrocarbon group having 1 to 8 carbon atoms or is a direct bond. However, ^{two or more of R 12 to} R ¹⁶ are bonded to each other to form a ring. It may be formed, or some hydrogen atoms of a monovalent or divalent hydrocarbon group may be substituted with a hydroxyl group.)

(In the formula, R ^{17 to} R ²¹ each independently represent Z, a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms, but at least one of ^{R 17 to} R ^{21 is} Representing Z above, R ²² and R ²³ each independently represent a divalent hydrocarbon group having 1 to 8 carbon atoms or are directly bonded, except that two of ^{R 17 to} R ^23. The above may be bonded to each other to form a ring, or some hydrogen atoms of a monovalent or divalent hydrocarbon group may be substituted with a hydroxyl group.)

(In the formula, R ^{24 to} R ²⁸ independently represent the above-mentioned Z, hydrogen atom or monovalent hydrocarbon group having 1 to 8 carbon atoms, but at least one of ^{R 24 to} R ^{28 is} Represents Z above.)

(In the formula, R ^{29 to} R ³⁶ each independently represent Z, a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms, but at least one of ^{R 29 to} R ^{36 is} Represents Z above.)

(In the formula, R ^{37 to} R ⁴² independently represent a hydrogen atom or a monovalent hydrocarbon group ^{having 1 to 6 carbon atoms, and R 43} is a monovalent hydrocarbon having 1 to 6 carbon atoms. It represents a hydrogen group, a monovalent hydrocarbon group or a cyano group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms are replaced with fluorine atoms.)

In the present invention, it is preferable that all ^{of R 5 to} R ⁷ in the general formula (2) represent the above Z.

In the present invention, it is preferable that two ^{of R 5 to} R ⁷ in the general formula (2) represent the above Z.

^{In the present invention, it is preferable that R 16} in the general formula (3) represents a methanediyl group, an ethanediyl group, a propanediyl group or a benzenediyl group.

In the present invention, it is preferable that all ^{of R 12 to} R ¹⁵ in the general formula (3) represent the above Z.

Further, the present invention is a non-aqueous electrolyte containing the above-mentioned water electrolyte additive, at least one selected from the group consisting of a solvent and a dispersion medium, and a supporting electrolyte. It is a non-aqueous electrolyte containing 01% by mass to 20% by mass.

Furthermore, the present invention is a non-aqueous electrolyte secondary battery containing a positive electrode, a negative electrode, and the non-aqueous electrolyte.

According to the present invention, it is possible to provide a non-aqueous electrolyte additive capable of improving the cycle characteristics and rate characteristics of a non-aqueous electrolyte secondary battery.

FIG. 1 is a vertical cross-sectional view schematically showing an example of the structure of a coin-type battery of the non-aqueous electrolyte secondary battery of the present invention. FIG. 2 is a schematic view showing a basic configuration of a cylindrical battery of the non-aqueous electrolyte secondary battery of the present invention. FIG. 3 is a perspective view showing the internal structure of the cylindrical battery of the non-aqueous electrolyte secondary battery of the present invention as a cross section.

Hereinafter, the present invention will be described in detail based on preferred embodiments.

<Non-aqueous electrolyte additive>
The non-aqueous electrolyte additive of the present invention comprises a compound having a nitrogen atom-containing silyl ester group represented by the general formula (1) in the molecule.

(In the formula, R ^{1 to} R ³ independently represent a monovalent hydrocarbon group having 1 to 6 carbon atoms, and R ⁴ represents a divalent hydrocarbon group having 1 to 8 carbon atoms. Represented, * represents a bond. However, some hydrogen atoms of monovalent or divalent hydrocarbons may be substituted with hydroxyl groups.)

In the general formula (1), the ^{monovalent hydrocarbon group having 1 to 6 carbon atoms represented by R 1 to} R ³ is, for example, a saturated fat having a linear or branched carbon atom number 1 to 6. Examples thereof include group hydrocarbon groups, unsaturated aliphatic hydrocarbon groups having linear or branched carbon atoms 2 to 6, and aromatic hydrocarbon groups having 6 carbon atoms. R ^{1 to} R ³ may represent the same group or different groups.

Specific examples of the monovalent hydrocarbon group having 1 to 6 carbon atoms represented by R ^{1 to} R ³ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, and an isobutyl group. , Tert-butyl group, pentyl group, sec-pentyl group, 1-ethylpropyl group, isopentyl group, 2,2-dimethylpropyl group, hexyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl Saturated aliphatic hydrocarbon groups such as groups, 2,2-dimethylbutyl groups, 2,3-dimethylbutyl groups, cyclopentyl groups and cyclohexyl groups, vinyl groups, allyl groups, butenyl groups, pentenyl groups, hexenyl groups and cyclopentenyl groups. , An unsaturated aliphatic hydrocarbon group such as a cyclohexenyl group, and an aromatic hydrocarbon group such as a phenyl group. From the viewpoint that the effect of the present invention becomes remarkable ^{, all of R 1 to} R ³ preferably represent a saturated aliphatic hydrocarbon group having 1 to 4 carbon atoms, and more preferably a methyl group.

In the general formula (1), the divalent hydrocarbon group having 1 to 8 carbon atoms represented by R ^4, linear or alkanediyl group having a branched having 1 to 8 carbon atoms, carbon atoms Examples thereof include a cycloalkanediyl group having 3 to 5, an arcendyl group having 2 to 8 carbon atoms, and an arenediyl group having 6 to 8 carbon atoms.

Specific examples of the divalent hydrocarbon group having 1 to 8 carbon atoms represented by R ⁴ include a methanediyl group, an ethanediyl group, a propanediyl group, an isopropanediyl group, a butanjiyl group, a pentandiyl group and a hexanediyl group. Alcandiyl group such as octanediyl group, cyclopropanediyl group, cyclopentandyl group, cycloalkandyl group such as cyclohexanediyl group, ethanediyl group, propendyl group, butendyl group, alkendyl group such as hexendyl group, benzene-1,4 Examples thereof include an areneyl group such as a −diyl group, a benzene-1,3-diyl group, and a benzene-1,2-diyl group. From the viewpoint of the effect of the present invention becomes remarkable, R ⁴ is, preferably represents a straight-chain alkanediyl group having 1 to 8 carbon atoms, more preferably represents a methylene bridge or an ethanediyl group.

The non-aqueous electrolyte additive of the present invention may have only one structure represented by the general formula (1) in the molecule, or may have a plurality of structures.

The non-aqueous electrolyte additive of the present invention can be produced by using a well-known production method without being particularly limited by the production method thereof. The non-aqueous electrolyte additive of the present invention can be produced, for example, by reacting the corresponding carboxylic acid compound with trialkylchlorosilane in a solvent.

The solvent used in the production of the non-aqueous electrolyte additive of the present invention includes a hydrocarbon solvent such as an aliphatic hydrocarbon solvent, an alicyclic hydrocarbon solvent, and an aromatic hydrocarbon solvent; an alcohol solvent, an ester solvent, and an aldehyde. Examples thereof include solvents containing carbon atoms such as based solvents, ketone solvents, ether solvents, and solvents containing carbon atoms and hetero atoms.

Specific examples of the solvent include aliphatic hydrocarbon solvents such as hexane, pentane, 2-ethylhexane, heptane, octane, decane, undecane, dodecane and tridecane; alicyclic hydrocarbon solvents such as cyclohexane and methylcyclohexane; benzene, Aromatic hydrocarbon solvents such as toluene, xylene, mesityrene, ethylbenzene, tert-butylbenzene, trifluoromethylbenzene, nitrobenzene, chlorobenzene, chlorotoluene, bromobenzene; alcohol solvents such as ethanol and butanol; ethyl acetate, butyl acetate and the like Ester solvent; aldehyde solvent such as formaldehyde, acetaldehyde, dimethylformamide; ketone solvent such as acetone, methyl ethyl ketone; ether solvent such as diethyl ether, dibutyl ether, tetrahydrofuran; carbon disulfide, diethyl ether, dibutyl ether, tetrahydrofuran Examples thereof include a solvent containing a carbon atom and a hetero atom. These solvents may be used alone or in combination of two or more kinds of solvents. Among these solvents, ester solvents are preferable.

Examples of the corresponding carboxylic acid compound include the following compounds. However, the present invention is not limited to these compounds.

(Phenylimino) diacetic acid (CAS number: 1137-73-1),
(Diphenylamino) acetic acid (CAS number: 60085-74-7),
N, N, N', N'-1,4-phenylenediamine tetraacetic acid (CAS number: 1099-02-1),
N-Methylglycine (CAS Number: 107-97-1),
N-Methyl-N-Phenylglycine (CAS Number: 40634-55-8),
N- (2-Hydroxyethyl) glycine (CAS No .: 5835-28-9),
N-Isopropylglycine (CAS Number: 3183-21-9),
N-Ethylglycine (CAS number: 627-01-0),
N-tert-Butylglycine (CAS Number: 58482-93-2),
N- (2-Hydroxyethyl) -N-glycine (CAS No .: 26294-19-9),
N, N-Dimethylglycine (CAS Number: 1118-68-9),
N-Ethyl-N-Methylglycine (CAS Registry Number: 740792-70-5),
N-isopropyl-N-methylglycine (CAS Registry Number: 108957-96-6),
N, N-diisopropylglycine (CAS number: 44976-832),
N-tert-butyl-N-methylglycine (CAS Registry Number: 253874-16-7),
3- (Dimethylamino) propionic acid (CAS number: 6300-04-5),
3- [Ethyl (Methyl) Amino] Propionic Acid (CAS Number: 1095030-20-8),
3- (Dimethylamino) -2-methylpropanoic acid (CAS No .: 2523-01-5),
4- (Dimethylamino) butanoic acid (CAS number: 693-11-8),
4- (Dimethylamino) -3-methylbutanoic acid (CAS No .: 13149966-40-9),
4- (Dimethylamino) -2-methylbutanoic acid (CAS number: 85224-99-6),
N-Methyl-N-Phenylglycine (CAS Number: 2611-88-3),
N-Isopropyl-N-Phenylglycine (CAS Number: 112211-91-3),
N-Butyl-N-Phenylglycine (CAS Number: 21911-64-8),
4-Dimethylaminobenzoic acid (CAS number: 619-84-1),
4-[(Dimethylamino) Methyl] Benzoic Acid (CAS Number: 18364-71-1),
N-carboxymethyl-4-methylglycine (CAS number: 4408-64-4),
Ethyliminodiacetic acid (CAS Registry Number: 5336-17-4),
N- (2-carboxyethyl) -N-methyl-β-alanine (CAS No .: 21555-95-3),
Pyrrolidine-3,4-dicarboxylic acid (CAS number: 105964-26-5),
1-Methylpyrrolidine-3-carboxylic acid (CAS No .: 412281-11-9),
(1-Methyl-2-pyrrolidinyl) acetic acid (CAS Registry Number: 5626-43-7),
2-Pyrrolidinyl acetic acid (CAS Registry Number: 56879-46-0),
Methylimidazolidine-1-carboxylic acid (CAS number unknown),
1H-Pyrazole-2,5-nicarboxylic acid (CAS number: 3112-31-0),
2- (1H-pyrazole-3yl) acetic acid (CAS Registry Number: 102732-63-8),
2- (5-Methyl-1H-pyrazole-3yl) propanoic acid (CAS No. 11903992-6-3),
2-Methyl-2- (5-methyl-1H-pyrazole-3-yl) propanoic acid (CAS number unknown),
4- (Dimethylamino) -2-methylbutanoic acid (CAS No .: 855224-99-6),
N-Phenylglycine (CAS Number: 103-01-5),
N, N-bis (2-hydroxyethyl) glycine (CAS number: 150-25-4),
Nitrilotriacetic acid (CAS No. 139-13-9),
N- (2-Hydroxyethyl) iminodiacetic acid (CAS number: 93-62-9),
N- (Hydroxyethyl) ethylenediamine-N, N', N "-triacetic acid (CAS number: 150-39-0),
Ethylenediaminetetraacetic acid (CAS number: 60-00-4),
Diethylenetriamine-N, N, N', N ", N" -pentacetic acid (CAS number: 67-43-6),
1-Diaminopropane-N, N, N', N'-tetraacetic acid (CAS number: 4408-81-5),
1,3-Diamino-2-hydroxypropane-N, N, N, N'-tetraacetic acid (CAS number: 3148-72-9),
Trimethylenediaminetetraacetic acid (CAS number: 1939-36-2),
[4- (2-Hydroxyethyl) piperazine-1-yl] acetic acid (CAS number: 124335-65-5),
Piperazine-1,4-diacetic acid (CAS number: 5430-78-4),
N- (4-Hydroxyphenyl) glycine (CAS Number: 122-87-2),
N- (4-Hydroxyphenyl) -N-methylglycine (CAS No .: 6118-9-9),
p-aminoacetic acid (CAS number: 150-13-0),
4- (Methylamino) acetic acid (CAS Registry Number: 10541-83-0),
4-[(Methylamino) methyl] benzene acid (CAS number: 96084-38-7),
4- (Dimethylamino) Phenylacetic Acid (CAS Number: 17078-28-3),
DL-Proline (CAS Number: 609-36-9),
Pyrrolidine-3-carboxylic acid (CAS number: 72580-53-1),
Pyrrolidine-3,4-dicarboxylic acid (CAS number unknown),
1-Methyl-2-pyrrole carboxylic acid (CAS number: 6973-60-0),
1,5-Dimethyl-1H-pyrrole-2-carboxylic acid (CAS No .: 73476-30-9),
2-Pyridinecarboxylic acid (CAS number: 98-98-6),
2,6-Pyridinedicarboxylic acid (CAS number: 499-832),
3,2'-Bipyridine-6-carboxylic acid (CAS number: 4392-87-4),
1H-pyrrole-2,5-nicarboxylic acid (CAS number: 937-27-9),
2,5-Pyrrolidinedicarboxylic acid (CAS number: 72000-65-8),
Pyrrolidine-2,4,6-tricarboxylic acid (CAS number: 536-20-9),
2,2'-Bipyridine-6.6'-dicarboxylic acid (CAS No .: 4479-74-7),
4,4', 4 "-Nitrilo benzoic acid (CAS number: 118996-38-6),
3,3', 3 "-nitrilotripropionic acid (CAS number: 817-11-8),
2- (3-Methyl-2-oxoimidazolidine-1-yl) acetic acid (CAS number unknown),
Ethylenediamine-N, N'-diacetic acid (CAS Registry Number: 5657-17-0),
Quinoxaline-5-carboxylic acid (CAS No .: 6924-66-9),
N, N'-1,4-phenylenediglycine (CAS number: 10097-07-1),
2-Methyl-2- (5-methyl-1H-pyrazole-3-yl) propionic acid (CAS No .: 2166642-39-1),
1,4,7-Triazacyclononane-N, N', N "-triacetic acid (CAS number: 56491-86-2),
Nicotinic acid (CAS Number: 59-67-6),
1-Isonicotinic acid (CAS Registry Number: 55-22-1),
2,2'-Bipyridine-3,3'-dicarboxylic acid (CAS number: 4433-01-6),
6-Methyl-2,4-pyridinedicarboxylic acid (CAS number: 499-50-3),
4-Ethynylpyridin-2,6-dicarboxylic acid (CAS No. 120517-48-8),
4-Vinylpyridine-2,6-dicarboxylic acid (CAS number: 1329121-35-8),
4-Methylpyridine-2-carboxylic acid (CAS No .: 4021-08-3),
6-Methylnicotinic acid (CAS Number: 3222-47-7),
Biisonicotinic acid (CAS Number: 6813-38-3),
2,4-Pyridinedicarboxylic acid (CAS number: 499-80-9),
2,5-Pyridinedicarboxylic acid (CAS number: 100-26-5),
N- (carboxycarbonyl) -glycine (CAS number: 5262-39-5)

The non-aqueous electrolyte additive of the present invention is preferably selected from the group of compounds represented by the general formulas (2) to (7) from the viewpoint that the effect of the present invention becomes remarkable. However, these compounds do not limit the present invention.

(In the formula, R ^{5 to} R ⁷ each independently represent Z, a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms, but at least one of ^{R 5 to} R ^{7 is Z.} However, two of R ^{5 to} R ⁷ may be bonded to each other to form a ring, and the monovalent hydrocarbon group contains a hetero atom (oxygen atom, nitrogen atom and sulfur atom). Alternatively, some hydrogen atoms of the monovalent hydrocarbon group may be replaced with a hydroxyl group.)

(In the formula, R ^{8 to} R ¹⁰ each independently represent a monovalent hydrocarbon group having 1 to 6 carbon atoms, * represents a bond, and R ¹¹ represents a carbon atom number 1 to 8 Represents the divalent hydrocarbon group of, or is a direct bond between the carbon atom of the carbonyl group and the bond.)

(In the formula, R ^{12 to} R ¹⁵ each independently represent Z, a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms, but at least one of ^{R 12 to} R ^{15 is Z. R 16} represents a divalent hydrocarbon group having 1 to 8 carbon atoms or is a direct bond. However, ^{two or more of R 12 to} R ¹⁶ are bonded to each other to form a ring. Alternatively, some hydrogen atoms of the monovalent or divalent hydrocarbon group may be replaced with a hydroxyl group.)

(In the formula, R ^{17 to} R ²¹ each independently represent Z, a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms, but at least one of ^{R 17 to} R ^{21 is Z.} Each of R ²² and R ²³ independently represents a divalent hydrocarbon group having 1 to 8 carbon atoms or is a direct bond. However, two or more of ^{R 17 to} R ^{23 are} They may be bonded to each other to form a ring, or some hydrogen atoms of a monovalent or divalent hydrocarbon group may be substituted with a hydroxyl group.)

(In the formula, R ^{24 to} R ²⁸ each independently represent Z, a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms, but at least one of ^{R 24 to} R ^{28 is Z.} Represents.)

(In the formula, R ^{29 to} R ³⁶ independently represent Z, a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms, but at least one of ^{R 29 to} R ^{36 is Z.} Represents.)

(In the formula, R ^{37 to} R ⁴² independently represent a hydrogen atom or a monovalent hydrocarbon group ^{having 1 to 6 carbon atoms, and R 43} is a monovalent hydrocarbon having 1 to 6 carbon atoms. It represents a hydrogen group, a monovalent hydrocarbon group or a cyano group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms are replaced with fluorine atoms.)

In the general formula (2), the ^{monovalent hydrocarbon group having 1 to 8 carbon atoms represented by R 5 to} R ⁷ is, for example, a saturated fat having a linear or branched carbon atom number 1 to 8. Examples thereof include group hydrocarbon groups, unsaturated aliphatic hydrocarbon groups having a linear or branched carbon atom number of 2 to 8, and aromatic hydrocarbon groups having 6 to 8 carbon atoms. R ^{5 to} R ⁷ may represent the same group or different groups.

Heteroatoms (nitrogen atom, oxygen atom and sulfur atom) may be contained in the saturated aliphatic hydrocarbon group having 1 to 8 carbon atoms represented by R ^{5 to} R ^7. Specific examples of the saturated aliphatic hydrocarbon group having 1 to 8 carbon atoms represented by R ^{5 to} R ⁷ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group and an isobutyl group. , Tert-butyl group, pentyl group, isopentyl group, sec-pentyl group, tert-pentyl group, hexyl group, sec-hexyl group, tert-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, Cyclopentyl group, cyclohexyl group, methylcyclohexyl group, norbornan group and the like can be mentioned.

Heteroatoms (nitrogen atom, oxygen atom and sulfur atom) may be contained in the unsaturated aliphatic hydrocarbon group having 2 to 8 carbon atoms represented by R ^{5 to} R ^7. Specific examples of the unsaturated aliphatic hydrocarbon group having 2 to 8 carbon atoms represented by R ^{5 to} R ⁷ include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, a cyclopentenyl group, and a cyclohexenyl group. Examples include a group, a cyclooctenyl group, a norbornen group and the like.

Heteroatoms (oxygen atom, nitrogen atom and sulfur atom) may be contained in the aromatic hydrocarbon group having 6 to 8 carbon atoms represented by R ^{5 to} R ^7. Specific examples of aromatic hydrocarbon groups having 6 to 8 carbon atoms represented by R ^{5 to} R ⁷ include phenyl group, methylphenyl group, ethylphenyl group, phenylmethyl group, phenylethyl group, benzyl group and pyrrole. Examples thereof include a group, a methylpyrrole group, a pyridyl group, a methylpyridyl group, a thienyl group and the like.

In the general formula (2), two of R ^{5 to} R ⁷ may be bonded to each other to form a ring. The structure of the ring is not particularly limited. The number of ring members is usually a 3-membered ring to a 10-membered ring, preferably a 5-membered ring to a 9-membered ring, and more preferably a 5-membered ring or a 6-membered ring, including a nitrogen atom. The ring may contain a hetero atom (oxygen atom, nitrogen atom, sulfur atom) in its structure. In addition, the ring may have an unsaturated bond in its structure. For example, pyrrolidine, methylpyrrolidine, pyrrole, methylpyrrole and the like can be mentioned.

In the group represented by Z, the monovalent hydrocarbon group having 1 to 6 carbon atoms represented by ^{R 8 to} R ^{10 is a carbon atom represented by R 1 to} R ³ in the general formula (1). The same as the monovalent hydrocarbon group of the number 1 to 6 can be mentioned.

In the group represented by Z, the divalent hydrocarbon group having 1 to 8 carbon atoms represented by ^{R 11} is 2 having 1 to 8 carbon atoms represented by ^{R 4 in the general formula (1).} The same as the valent hydrocarbon group can be mentioned.

In the general formula (2), at least one of ^{R 5 to} R ^{7 represents Z.} From the viewpoint of excellent cycle characteristics and rate characteristics of a nonaqueous electrolyte secondary battery, it is preferable to represent two or more Z of R ⁵ to R ^7, more that all R ⁵ to R ⁷ represents Z preferable.

From the viewpoint of excellent cycle characteristics and rate characteristics of the non-aqueous electrolyte secondary battery, R ^{8 to} R ^{10 in} Z of the compound represented by the general formula (2) may represent a methyl group, an ethyl group or a phenyl group. It is preferable, and it is more preferable to represent a methyl group. From the viewpoint of excellent cycle characteristics and rate characteristics of the non-aqueous electrolyte secondary battery, R ¹¹ in Z of the compound represented by the general formula (2) represents a methanediyl group, an ethanediyl group, a propanediyl group or a benzenediyl group. It is preferable, and it is more preferable to represent a methanediyl group, an ethanediyl group or a propanediyl group.

Specific examples of the compound represented by the general formula (2) include the following compounds 1-1 to 1-60 when ^{R 8 to} R ^{10 in Z represent a methyl group.} It is not limited to these compounds.

From the viewpoint of excellent cycle characteristics and rate characteristics of the non-aqueous electrolyte secondary battery, the compound represented by the general formula (2) is preferably a compound having a tertiary amine structure, and compounds 1-2 and 1-8. , Compound 1-24, Compound 1-45, Compound 1-46, Compound 1-54, Compound 1-55, Compound 1-58 and Compound 1-59 are more preferred, Compound 1-2, Compound 1-8, Compound 1-8. 1-58 and compound 1-59 are more preferred.

The compound represented by the general formula (2) can be produced by reacting the corresponding carboxylic acid compound with trialkylchlorosilane in a butyl acetate solvent. For example, compound 1-1 can be produced by reacting trimethylchlorosilane with N-methylaminoacetic acid in a butyl acetate solvent, and compound 1-2 can be produced by reacting trimethylchlorosilane with N, N-dimethylamino. It can be produced by reacting with acetic acid in a butyl acetate solvent.

In the general formula (3), the monovalent hydrocarbon group having 1 to 8 carbon atoms represented by ^{R 12 to} R ¹⁵ is the number of carbon atoms represented by ^{R 5 to} R ^{7 in the general formula (2).} The same as 1 to 8 monovalent hydrocarbon groups can be mentioned. The divalent hydrocarbon group having 1 to 8 carbon atoms represented by ^{R 16} is the same as the divalent hydrocarbon group having 1 to 8 carbon atoms represented by ^{R 4 in the general formula (1).} Can be mentioned. R ^{12 to} R ¹⁵ may represent the same group or different groups.

In the general formula (3), ^{two or more of R 12 to} R ¹⁶ may be bonded to each other to form a ring. The structure of the ring is not particularly limited. The number of ring members is usually a 3-membered ring to a 10-membered ring, more preferably a 5-membered ring to a 9-membered ring, and further preferably a 5-membered ring or a 6-membered ring, including a nitrogen atom. The ring may contain a hetero atom (oxygen atom, nitrogen atom, sulfur atom) in its structure. In addition, the ring may have an unsaturated bond in its structure. For example, pyrrolidine, pyrrole, imidazolidinen, imidazole, piperazine and the like can be mentioned.

In the general formula (3), at least one of ^{R 12 to} R ^{15 represents Z.} From the viewpoint of cycle characteristics and rate characteristics of a nonaqueous electrolyte secondary battery is excellent, it is preferable to represent two or more Z of R ¹² to R ^15, more that all R ¹² to R ¹⁵ represents a Z preferable. From the viewpoint of excellent cycle characteristics and rate characteristics of the non-aqueous electrolyte secondary battery, R ¹⁶ preferably represents a methanediyl group, an ethanediyl group, a propanediyl group or a benzenediyl group, and may represent a methanediyl group or an ethanediyl group. More preferable.

From the viewpoint of excellent cycle characteristics and rate characteristics of the non-aqueous electrolyte secondary battery, R ^{8 to} R ^{10 in} Z of the compound represented by the general formula (3) may represent a methyl group, an ethyl group or a phenyl group. It is preferable, and it is more preferable to represent a methyl group. From the viewpoint of excellent cycle characteristics and rate characteristics of the non-aqueous electrolyte secondary battery, R ¹¹ in Z of the compound represented by the general formula (3) represents a methanediyl group, an ethanediyl group, a propanediyl group or a benzenediyl group. It is preferable, and it is more preferable to represent a methanediyl group or an ethanediyl group.

Specific examples of the compound represented by the general formula (3) include the following compounds 2-1 to 2-13 when ^{R 8 to} R ^{10 in Z represent a methyl group.} It is not limited to these compounds.

From the viewpoint of excellent cycle characteristics and rate characteristics of the non-aqueous electrolyte secondary battery, the compound represented by the general formula (3) is preferably a compound having a tertiary amine structure, and compounds 2-2 and 2-3. , Compound 2-4 and Compound 2-13 are more preferred.

The compound represented by the general formula (3) can be produced by reacting the corresponding carboxylic acid compound with trialkylchlorosilane in a butyl acetate solvent. For example, Compound 2-3 can be produced by reacting trimethylchlorosilane with ethylenediamine-N, N, N', N'-tetraacetic acid in a butyl acetate solvent.

In the general formula (4), the monovalent hydrocarbon group having 1 to 8 carbon atoms represented by ^{R 17 to} R ²¹ has the number of carbon atoms represented by ^{R 5 to} R ^{7 in the general formula (2).} The same as 1 to 8 monovalent hydrocarbon groups can be mentioned. As the ^{divalent hydrocarbon group having 1 to 8 carbon atoms represented by R 22} and R ²³ , the divalent hydrocarbon having 1 to 8 carbon atoms represented by ^{R 4} of Z in the general formula (1) is used. The same as the hydrogen group can be mentioned. R ^{17 to} R ²¹ may represent the same group or different groups.

In the general formula (4), ^{two or more of R 17 to} R ²³ may be bonded to each other to form a ring. The structure of the ring is not particularly limited. The number of ring members is usually a 3-membered ring to a 20-membered ring, more preferably a 5-membered ring to a 10-membered ring, and further preferably a 5-membered ring, a 6-membered ring or a 9-membered ring, including a nitrogen atom. The ring may contain a hetero atom (oxygen atom, nitrogen atom, sulfur atom) in its structure. In addition, the ring may have an unsaturated bond in its structure. For example, pyrrolidine, pyrrole, imidazolidine, imidazole, piperazine, triazine, triazacyclohexane, triazacyclononane and the like can be mentioned.

In the general formula (4), at least one of ^{R 17 to} R ^{21 represents Z.} From the viewpoint of cycle characteristics and rate characteristics of a nonaqueous electrolyte secondary battery is ^excellent, three or more of preferably represent a Z of R 17 ^{to R 21,} or four of R 17 ^{to R 21} represents Z It is more preferable that all of ^{R 17 to} R ^{21 represent Z.} From the viewpoint of excellent cycle characteristics and rate characteristics of the non-aqueous electrolyte secondary battery, R ²² and R ²³ in the compound represented by the general formula (4) are methanediyl groups, ethanediyl groups, propanediyl groups or benzenediyl groups. It is preferable to represent it, and it is more preferable to represent a methanediyl group, an ethanediyl group or a propanediyl group.

From the viewpoint of excellent cycle characteristics and rate characteristics of the non-aqueous electrolyte secondary battery, R ^{8 to} R ^{10 in} Z of the compound represented by the general formula (4) may represent a methyl group, an ethyl group or a phenyl group. It is preferable, and it is more preferable to represent a methyl group. From the viewpoint of excellent cycle characteristics and rate characteristics of the non-aqueous electrolyte secondary battery, R ¹¹ in Z of the compound represented by the general formula (4) represents a methanediyl group, an ethanediyl group, a propanediyl group or a benzenediyl group. It is preferable, and it is more preferable to represent a methanediyl group, an ethanediyl group or a propanediyl group.

Specific examples of the compound represented by the general formula (4) include the following compounds 3-1 to 3-4 when ^{R 8 to} R ^{10 in Z represent a methyl group.} It is not limited to compounds.

From the viewpoint of excellent cycle characteristics and rate characteristics, the compounds represented by the general formula (4) are preferably compound 3-1 and compound 3-2, and more preferably compound 3-2.

The compound represented by the general formula (4) can be produced by reacting the corresponding carboxylic acid compound with trialkylchlorosilane in a butyl acetate solvent. For example, compound 3-2 can be produced by reacting trimethylchlorosilane with diethylenetriaminepentaacetic acid in a butyl acetate solvent.

In the general formula (5), the monovalent hydrocarbon group having 1 to 8 carbon atoms represented by ^{R 24 to} R ²⁸ is the number of carbon atoms represented by ^{R 5 to} R ^{7 in the general formula (2).} The same as 1 to 8 monovalent hydrocarbon groups can be mentioned. R ^{24 to} R ²⁸ may represent the same group or different groups.

In the general formula (5), at least one of ^{R 24 to} R ^{28 represents Z.} From the viewpoint of cycle characteristics and rate characteristics of a nonaqueous electrolyte secondary battery is ^excellent, it is preferable to represent two or more Z of R 24 ^{to R 28,} 3 or more of the R 24 ^{to R 28} represents Z Is more preferable.

From the viewpoint of excellent cycle characteristics and rate characteristics of the non-aqueous electrolyte secondary battery, R ^{8 to} R ^{10 in} Z of the compound represented by the general formula (5) may represent a methyl group, an ethyl group or a phenyl group. It is preferable, and it is more preferable to represent a methyl group. From the viewpoint of excellent cycle characteristics and rate characteristics of the non-aqueous electrolyte secondary battery, R ¹¹ in Z of the compound represented by the general formula (5) represents a methanediyl group, an ethanediyl group, a propanediyl group or a benzenediyl group. It is preferable, and it is more preferable to represent a methanediyl group, an ethanediyl group or a propanediyl group.

Specific examples of the compound represented by the general formula (5) include the following compounds 4-1 to 4-13 when ^{R 8 to} R ^{10 in Z represent a methyl group.} It is not limited to these compounds.

From the viewpoint of excellent cycle characteristics and rate characteristics, the compounds represented by the general formula (5) include compound 4-1, compound 4-2, compound 4-5, compound 4-8, compound 4-9 and compound. 4-13 is preferable, and compound 4-1 and compound 4-5, compound 4-8 and compound 4-13 are more preferable.

The compound represented by the general formula (5) can be produced by reacting the corresponding carboxylic acid compound with trialkylchlorosilane in a butyl acetate solvent. For example, compound 4-1 can be produced by reacting trimethylchlorosilane with a pyridine-2-carboxylic acid in a butyl acetate solvent.

In the general formula (6), the hydrocarbon group having 1 to 8 carbon atoms represented by ^{R 29 to} R ³⁶ is a hydrocarbon group having 1 to 8 carbon atoms represented by ^{R 5 to} R ^{7 in the general formula (2).} The same as the hydrocarbon group of. R ^{29 to} R ³⁶ may represent the same group or different groups.

In the general formula (6), at least one of ^{R 29 to} R ^{36 represents Z.} From the viewpoint of excellent cycle characteristics and rate characteristics of the non-aqueous electrolyte secondary battery, it is preferable that two or more of ^{R 29 to} R ^{36 represent Z.}

From the viewpoint of excellent cycle characteristics and rate characteristics of the non-aqueous electrolyte secondary battery, R ^{8 to} R ^{10 in} Z of the compound represented by the general formula (6) may represent a methyl group, an ethyl group or a phenyl group. It is preferable, and it is more preferable to represent a methyl group. ^{From the viewpoint of excellent cycle characteristics and rate characteristics, R 11} in Z of the compound represented by the general formula (6) preferably represents a methanediyl group, an ethanediyl group, a propanediyl group or a benzenediyl group, and the methanediyl group, It is more preferable to represent an ethanediyl group or a propanediyl group.

Specific examples of the compound represented by the general formula (6) include the following compounds 5-1 to 5-5 when ^{R 8 to} R ^{10 in Z represent a methyl group.} It is not limited to these compounds.

From the viewpoint of excellent cycle characteristics and rate characteristics, compounds 5-1 and 5-3 are preferable as the compounds represented by the general formula (6).

The compound represented by the general formula (6) can be produced by reacting the corresponding carboxylic acid compound with trialkylchlorosilane in a butyl acetate solvent. For example, compound 5-1 can be produced by reacting trimethylchlorosilane with [2,2'-bipyridine] -6-carboxylic acid in a butyl acetate solvent.

In the general formula (7), the monovalent hydrocarbon group having 1 to 6 carbon atoms represented by ^{R 37 to} R ⁴² is the number of carbon atoms represented by ^{R 1 to} R ^{3 in the general formula (1).} The same as 1 to 6 monovalent hydrocarbon groups can be mentioned. R ^{37 to} R ⁴² may represent the same group or different groups.

In the general formula (7), represented by R ^43, a part or all of the hydrogen atoms monovalent hydrocarbon group having a carbon number of 1 to 6 substituted with fluorine atoms, e.g., fluoromethyl group, Difluoromethyl group, trifluoromethyl group, fluoroethyl group, difluoroethyl group, trifluoroethyl group, pentafluoroethyl group, fluoropropyl group, difluoropropyl group, heptafluoropropyl group, fluorocyclopentyl group, fluorocyclohexyl group, pentafluoro Examples include a phenyl group.

From the viewpoint of excellent cycle characteristics and rate characteristics, in the general formula (7), R ⁴³ preferably represents a methyl group, an ethyl group, a phenyl group, a trifluoromethyl group, a pentafluorophenyl group or a cyano group, and methyl. More preferably, it represents a group, a trifluoromethyl group or a cyano group.

From the viewpoint of excellent cycle characteristics and rate characteristics of the non-aqueous electrolyte secondary battery, R ^{8 to} R ^{10 in} Z of the compound represented by the general formula (7) may represent a methyl group, an ethyl group or a phenyl group. It is preferable, and it is more preferable to represent a methyl group. From the viewpoint of excellent cycle characteristics and rate characteristics of the non-aqueous electrolyte secondary battery, R ¹¹ in Z of the compound represented by the general formula (7) represents a methanediyl group, an ethanediyl group, a propanediyl group or a benzenediyl group. It is preferable, and it is more preferable to represent a methanediyl group, an ethanediyl group or a propanediyl group.

Specific examples of the compound represented by the general formula (7) include the following compounds 6-1 to 6-5 when ^{R 37 to} R ^{42 represent a methyl group.} It is not limited to compounds.

From the viewpoint of excellent cycle characteristics and rate characteristics, the compounds represented by the general formula (7) are preferably compound 6-1, compound 6-3 and compound 6-4.

The compound represented by the general formula (7) can be produced by reacting the corresponding carboxylic acid compound with trialkylchlorosilane in a butyl acetate solvent. For example, compound 6-1 can be produced by reacting trimethylchlorosilane with 2,2'-(acetylazaneyl) diacetic acid in a butyl acetate solvent.

<Non-aqueous electrolyte>
The non-aqueous electrolyte of the present invention includes at least one selected from the group consisting of the above-mentioned non-aqueous electrolyte additive, solvent and dispersion medium, and a supporting electrolyte. The non-aqueous electrolyte additive is contained in an amount of 0.01% by mass to 20% by mass, preferably 0.05% by mass to 10% by mass, and more preferably 0.1% by mass to 5% by mass, based on the non-aqueous electrolyte. Included in% by mass. When the content of the non-aqueous electrolyte additive is less than 0.01% by mass, the cycle characteristics and rate characteristics of the non-aqueous electrolytic secondary battery using the non-aqueous electrolyte of the present invention cannot exhibit sufficient performance. There is. On the other hand, if the content of the non-aqueous electrolyte additive is more than 20% by mass, the effect commensurate with the blending amount cannot be obtained, and the battery characteristics may be adversely affected.

The form of the non-aqueous electrolyte of the present invention is not particularly limited, and as a liquid form obtained by using an organic solvent as a solvent, or as a solvent or a dispersion medium, a polymer obtained by dissolving a polymer compound in an organic solvent and gelling. Examples thereof include a polymer gel form obtained by using a gel, a polymer form obtained by using a polymer compound as a dispersion medium without using a solvent, and the like.

As the solvent used for the non-aqueous electrolyte of the present invention, an organic solvent usually used for the non-aqueous electrolyte of the non-aqueous electrolyte secondary battery can be used. Specific examples of the organic solvent include, for example, a saturated cyclic carbonate compound, a saturated cyclic ester compound, a sulfoxide compound, a sulfone compound, an amide compound, a saturated chain carbonate compound, a chain ether compound, a cyclic ether compound, a saturated chain ester compound and the like. Can be mentioned. Only one kind of these organic solvents may be used, or two or more kinds may be used in combination.

Examples of the saturated cyclic carbonate compound include ethylene carbonate, 1,2-propylene carbonate, 1,3-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate, 1,1-dimethylethylene carbonate and the like. Be done.

Examples of the saturated cyclic ester compound include γ-butyrolactone, γ-valerolactone, γ-caprolactone, δ-hexanolactone, and δ-octanolactone.

Examples of the sulfoxide compound include dimethyl sulfoxide, diethyl sulfoxide, dipropyl sulfoxide, diphenyl sulfoxide, thiophene and the like.

Examples of the sulfone compound include dimethyl sulfone, diethyl sulfone, dipropyl sulfone, diphenyl sulfone, sulfolane (also referred to as tetramethylene sulfone), 3-methyl sulfolane, 3,4-dimethyl sulfolane, 3,4-diphenylmethyl sulfolane, and the like. Examples thereof include sulfolene, 3-methylsulfolene, 3-ethylsulfolene, 3-bromomethylsulfone and the like. Among these, sulfolane and tetramethylsulfolane are preferable.

Examples of the amide compound include N-methylpyrrolidone, dimethylformamide, dimethylacetamide and the like.

Examples of the saturated chain carbonate compound include dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, ethyl butyl carbonate, methyl-tert-butyl carbonate, diisopropyl carbonate, tert-butylpropyl carbonate and the like.

Examples of the chain ether compound and the cyclic ether compound include dimethoxyethane, ethoxymethoxyethane, diethoxyethane, tetrahydrofuran, dioxolane, dioxane, 1,2-bis (methoxycarbonyloxy) ethane, and 1,2-bis (ethoxycarbonyl). Oxy) ethane, 1,2-bis (ethoxycarbonyloxy) propane, ethylene glycol bis (trifluoroethyl) ether, propylene glycol bis (trifluoroethyl) ether, ethylene glycol bis (trifluoromethyl) ether, diethylene glycol bis (tri) Fluoroethyl) ether and the like can be mentioned, and among these, dioxolane is preferable.

The saturated chain ester compound is preferably a monoester compound or a diester compound having a total number of carbon atoms in the molecule of 2 to 8, and specific compounds include, for example, methyl formate, ethyl formate, methyl acetate, and acetate. Ethyl, propyl acetate, isobutyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, methyl isobutyrate, methyl trimethyl acetate, ethyl trimethyl acetate, methyl malonate, ethyl malonate, methyl succinate, ethyl succinate, Examples thereof include methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethylene glycol diacetyl, propylene glycol diacetyl, etc., such as methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl acetate, isobutyl acetate, butyl acetate, methyl propionate. And ethyl propionate are preferred.

Among these organic solvents, saturated cyclic carbonate compounds, saturated cyclic ester compounds, sulfoxide compounds, sulfon compounds, and amide compounds are high in relative permittivity and play a role in increasing the dielectric constant of the non-aqueous electrolyte of the present invention. Preferably, a saturated cyclic carbonate compound is more preferred.

Further, among these organic solvents, the viscosity of the non-aqueous electrolyte of the present invention can be lowered, the mobility of electrolyte ions can be increased, and the battery characteristics such as output density can be improved. Therefore, saturated chain carbonate compounds, chain ether compounds, cyclic ether compounds and saturated chain ester compounds are preferable. Further, a saturated chain carbonate compound is particularly preferable because it has a low viscosity and can improve the performance of the non-aqueous electrolyte at a low temperature.

As other organic solvents, for example, acetonitrile, propionitrile, nitromethane, derivatives thereof, and various ionic liquids can also be used.

Examples of the polymer compound used for preparing the non-aqueous electrolyte in the form of a polymer gel include polyethylene oxide, polypropylene oxide, polyvinyl chloride, polyacrylonitrile, polymethylmethacrylate, polyethylene, polyvinylidene fluoride, polyhexafluoropropylene and the like.

Examples of the polymer compound used as it is as a dispersion medium include polyethylene oxide, polypropylene oxide, polystyrene sulfonic acid and the like.

When the composition in the form of a polymer gel or the polymer compound itself is used as a solvent or a dispersion medium, there are no particular restrictions on the compounding ratio and the compounding method in the non-aqueous electrolyte of the present invention, and the compounding ratio known in the present art. , A known compounding method can be adopted.

The form of the non-aqueous electrolyte of the present invention is not particularly limited, but one containing a solvent is preferable, and a liquid form is more preferable because the production process is simple.

Examples of the supporting electrolyte used in the non-aqueous electrolyte of the present invention include alkali metal salts such as lithium salt, sodium salt and potassium salt, and alkaline earth metal salts such as magnesium salt and calcium salt.
The lithium salt is not particularly limited, and a known lithium salt can be used. Specific examples of lithium salts include, for example, LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiN. (SO ₂ F) ₂ , LiC (CF ₃ SO ₂ ) ₃ , LiB (CF ₃ SO ₃ ) ₄ , LiB (C ₂ O ₄ ) ₂ , LiBF ₂ (C ₂ O ₄ ), LiSbF ₆ , LiSiF ₅ , LiSCN _{, LiClO 4, LiCl, LiF,} LiBr, LiI, LiAlF 4, LiAlCl 4, LiPO 2 F 2 , and derivatives thereof.

When the non-aqueous electrolyte form of the present invention is in the liquid form or the polymer gel form, the supporting electrolytes include LiPF ₆ , LiBF ₄ , LiClO ₄ , LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , and LiN ( Consists of C ₂ F ₅ SO ₂ ) ₂ , LiN (SO ₂ F) _{2 , LiPO 2} F ₂ , LiC (CF ₃ SO ₂ ) ₃ , LiCF ₃ SO ₃ derivative and LiC (CF ₃ SO ₂ ) ₃ derivative It is preferable to use at least one lithium salt selected from the group.

When the non-aqueous electrolyte form of the present invention is a polymer form, the supporting electrolytes include LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiN (SO ₂ F) ₂ , and LiC. It is preferable to use at least one selected from the group consisting of (CF ₃ SO ₂ ) ₃ , LiB (CF ₃ SO ₃ ) ₄ and LiB (C ₂ O ₄ ) _2.

As the supporting electrolyte used in the non-aqueous electrolyte of the present invention, an alkali metal salt such as a sodium salt in which lithium in the lithium salt is replaced with sodium and a potassium salt in which lithium in the lithium salt is replaced with potassium may be used. , Magnesium salt, calcium salt and other alkaline earth metal salts may be used.

If the concentration of the supporting electrolyte in the non-aqueous electrolyte of the present invention is too low, a sufficient current density may not be obtained when used in a non-aqueous electrolyte secondary battery, while if it is too high, the non-aqueous electrolyte is stable. It is preferably 0.5 mol / L to 7 mol / L, more preferably 0.8 mol / L to 1.8 mol / L, because it may impair the properties.

The application of the non-aqueous electrolyte of the present invention is not particularly limited, but it can be used as an electrolyte for a power storage device such as a capacitor, and can be suitably used as a non-aqueous electrolyte used in a non-aqueous electrolyte secondary battery.

The non-aqueous electrolyte of the present invention is a known electrolyte additive such as an electrode film forming agent, an antioxidant, a flame retardant, and an overcharge inhibitor in order to improve the battery life and safety of a non-aqueous electrolyte secondary battery. May be further included. When a known electrolyte additive is used, if the concentration is too small, the addition effect cannot be exhibited, and if it is too large, the characteristics of the non-aqueous electrolyte may be adversely affected. It is preferably 01% by mass to 10% by mass, and more preferably 0.1% by mass to 5% by mass.

<Non-aqueous electrolyte secondary battery>
The non-aqueous electrolyte secondary battery of the present invention (hereinafter referred to as "the battery of the present invention") includes a positive electrode containing a positive electrode active material, a negative electrode containing a negative electrode active material, and the above-mentioned non-aqueous electrolyte. In the present invention, it is preferable to interpose a separator between the positive electrode and the negative electrode.

The positive electrode used in the battery of the present invention can be manufactured according to a known method. For example, an electrode mixture paste containing a positive electrode active material, a binder and a conductive additive is applied to a current collector and dried by applying an electrode mixture paste slurryed with an organic solvent or water to the electrode mixture on the current collector. A layered positive electrode can be produced.

A known positive electrode active material can be used. Examples of known positive electrode active materials include lithium transition metal composite oxides, lithium-containing transition metal phosphoric acid compounds, lithium-containing silicate compounds, and lithium-containing transition metal sulfate compounds. As the transition metal of the lithium transition metal composite oxide, vanadium, titanium, chromium, manganese, iron, cobalt, nickel, copper and the like are preferable. Only one kind of these positive electrode active materials may be used, or two or more kinds may be used in combination.

Specific examples of the lithium transition metal composite oxide include a lithium cobalt composite oxide such _{as LiCoO 2} , a lithium nickel composite oxide such as _{LiNiO 2} , and a lithium manganese composite oxide such as _{LiMnO 2} , LiMn ₂ O ₄ , and Li ₂ MnO _3. Some of the transition metal atoms that are the main constituents of these lithium transition metal composite oxides are aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, lithium, nickel, copper, zinc, magnesium, gallium, zirconium, etc. Examples thereof include those substituted with other metals. Lithium transition metal composite oxides in which a part of the main transition metal atom is replaced with another metal are, for example, Li _1.1 Mn _1.8 Mg _0.1 O ₄ , Li _1.1 Mn _1.85 Al. _0.05 O ₄ , LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , LiNi _0.8 Co _0.1 Mn _0.1 O ₂ , LiNi _0.5 Mn _0.5 O ₂ , LiNi _{0. 80} Co _0.17 Al _0.03 O ₂ , LiNi _0.80 Co _0.15 Al _0.05 O ₂ , LiNi _1/3 Co _1/3 Mn _1/3 O ₂ , LiNi _0.6 Co _0.2 Examples thereof include Mn _0.2 O ₂ , LiMn _1.8 Al _0.2 O ₄ , LiNi _0.5 Mn _1.5 O ₄ , Li ₂ MnO _{3- LiMO 2} (M = Co, Ni, Mn) and the like.

As the transition metal of the lithium-containing transition metal phosphoric acid compound, vanadium, titanium, manganese, iron, cobalt, nickel and the like are preferable, and specific examples thereof include, for example, LiFePO ₄ , LiMxFe _1-x PO ₄ (M = Co, Ni). , Mn) and other iron phosphate compounds, LiCoPO4 and other cobalt phosphate compounds, and some of the transition metal atoms that are the main constituents of these lithium transition metal phosphate compounds are aluminum, titanium, vanadium, chromium, manganese, and iron. , Cobalt, lithium, nickel, copper, zinc, magnesium, gallium, zirconium, niobium and other metals substituted, vanadium phosphate compounds such as _{Li 3} V ₂ (PO ₄ ) _{3 and the like.}

Examples of the lithium-containing silicate compound include Li ₂ FeSiO ₄ .

Examples of the lithium-containing transition metal sulfuric acid compound include LiFeSO ₄ , LiFeSO ₄ F and the like.

As the positive electrode active material, sulfur, sulfur-modified organic compounds, sulfur - may be a carbon _{composite, Li 2 S x (x =} 1~8).

In the present specification, the sulfur-carbon complex and the sulfur-modified organic compound are organic compounds containing at least 25% by mass or more, preferably 30% by mass or more of sulfur, and are non-aqueous compounds that can occlude and release lithium ions. Electrolyte A compound that can be used as an electrode active material for secondary batteries.

The sulfur-carbon complex and the sulfur-modified organic compound are obtained by heat-treating the organic compound and sulfur. Examples of the compound obtained by heat-treating the organic compound and sulfur include a sulfur-modified polyacrylonitrile compound, a sulfur-modified elastomer compound, a sulfur-modified pitch compound, a sulfur-modified polynuclear aromatic ring compound, a sulfur-modified aliphatic hydrocarbon oxide, and a sulfur-modified polyether. Examples thereof include compounds, polythienoacene compounds, sulfur-modified polyamide compounds, and polycarbon sulfide. These compounds are a mixture of sulfur, polyacrylic compounds, elastomer compounds, pitch compounds, polynuclear aromatic ring compounds, aliphatic hydrocarbon oxides, polyether compounds, polyacene compounds, polyamide compounds, hexachlorobutadiene, etc., and are non-oxidized. It can be produced by heat-modifying at 250 ° C. to 600 ° C. in a sexual atmosphere. When heating these compounds with sulfur, only one of the above compounds may be used, or two or more of them may be used in combination. Among these sulfur-modified organic compounds, a sulfur-modified polyacrylonitrile compound is preferable from the viewpoint of obtaining a large charge / discharge capacity.

The non-oxidizing atmosphere is an atmosphere in which the oxygen concentration is less than 5% by volume, preferably less than 2% by volume, and more preferably substantially free of oxygen, that is, an inert gas atmosphere such as nitrogen, helium, or argon, or sulfur. Represents a gas atmosphere.

The sulfur-modified polyacrylonitrile compound is a compound obtained by heat-treating a polyacrylonitrile compound and elemental sulfur in a non-oxidizing atmosphere. Polyacrylonitrile compounds are homopolymers of acrylonitrile or copolymers of acrylonitrile with other monomers. When the content of acrylonitrile in the polyacrylonitrile compound is low, the battery performance is lowered, and further, carbonization is relatively easy and the carbide exhibits relatively high conductivity, so that the utilization rate of the active material is improved and the capacity is increased. From the viewpoint of being able to do so, the content of acrylonitrile in the copolymer of acrylonitrile and other monomers is preferably at least 90% by mass, and polyacrylonitrile homopolymer is more preferable. Other monomers include, for example, acrylic acid, vinyl acetate, N-vinylformamide, N, N'-methylenebis (acrylamide). The temperature of the heat treatment is preferably 250 ° C. to 550 ° C. The sulfur content of the sulfur-modified polyacrylonitrile is preferably 30% by mass to 60% by mass from the viewpoint of obtaining a large charge / discharge capacity.

The sulfur-modified elastomer compound is a compound obtained by heat-treating a mixture of rubber and elemental sulfur in a non-oxidizing atmosphere. Examples of the rubber include natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, acrylonitrile butadiene rubber and the like. One type of these rubbers can be used alone, and two or more types can be used in combination. The raw material rubber may be vulcanized rubber or unvulcanized rubber. The temperature of the heat treatment is preferably 250 ° C. to 550 ° C. The sulfur content of the sulfur-modified elastomer compound is preferably 40% by mass to 70% by mass from the viewpoint of obtaining a large charge / discharge capacity.

The sulfur-modified pitch compound is a compound obtained by heat-treating a mixture of pitches and elemental sulfur in a non-oxidizing atmosphere. Pitches include petroleum pitch, coal pitch, mesophase pitch, asphalt, coal tar, coal tar pitch, organic synthetic pitch obtained by polycondensation of condensed polycyclic aromatic hydrocarbon compounds, and heteroatomic condensed polycyclic fragrance. Examples thereof include an organic synthetic pitch obtained by polycondensation of group hydrocarbon compounds. Pitches are a mixture of various compounds and contain condensed polycyclic aromatics. The condensed polycyclic aromatics contained in the pitches may contain one kind or two or more kinds. Condensed polycyclic aromatics may contain nitrogen or sulfur in the ring structure. The temperature of the heat treatment is preferably 300 ° C. to 500 ° C. The sulfur content of the sulfur-modified pitch compound is preferably 25% by mass to 70% by mass from the viewpoint of obtaining a large charge / discharge capacity.

Sulfur-modified polynuclear aromatic ring compounds include, for example, benzene-based aromatic ring compounds such as naphthalene, anthracene, tetracene, pentacene, phenanthrene, chrysene, picene, pyrene, benzopyrene, perylene, and coronen, and some of the benzene-based aromatic ring compounds. Non-oxidizing a mixture of simple condiments and a polynuclear aromatic ring compound such as an aromatic ring compound that has become a ring or a heteroatomic heteroatomic ring compound in which some of these carbon atoms are replaced with sulfur, oxygen, nitrogen, etc. It is a compound obtained by heat treatment in a sexual atmosphere. Further, the polynuclear aromatic ring compound contains substituents such as an alkyl group having 1 to 12 carbon atoms, an alkoxyl group, a hydroxyl group, a carboxyl group, an amino group, an aminocarbonyl group, an aminothio group, a mercaptothiocarbonylamino group and a carboxylalkylcarbonyl group. You may have it. The substituent may be linear or have a branch. The temperature of the heat treatment is preferably 250 ° C. to 550 ° C. The sulfur content of the sulfur-modified polynuclear aromatic ring compound is preferably 40% by mass to 70% by mass from the viewpoint of obtaining a large charge / discharge capacity.

Sulfur-modified aliphatic hydrocarbon oxides are non-aliphatic hydrocarbon oxides such as aliphatic alcohols, aliphatic aldehydes, aliphatic ketones, aliphatic epoxides, and fatty acids, and simple sulfur. It is a compound obtained by heat treatment in an oxidizing atmosphere. The temperature of the heat treatment is preferably 300 ° C. to 500 ° C. The sulfur content of the sulfur-modified aliphatic hydrocarbon oxide is preferably 45% by mass to 75% by mass from the viewpoint of obtaining a large charge / discharge capacity.

The sulfur-modified polyether compound is a compound obtained by heat-treating a polyether compound and elemental sulfur in a non-oxidizing atmosphere. Examples of the polyether compound include polyethylene glycol, polypropylene glycol, ethylene oxide / propylene oxide copolymer, polytetramethylene glycol and the like. The polyether compound may have an alkyl ether group, an alkylphenyl ether group, or an acyl group at the end, or may be an ethylene oxide adduct of a polyol such as glycerin or sorbitol. The temperature of the heat treatment is preferably 250 ° C. to 500 ° C. The sulfur content of the sulfur-modified polyether compound is preferably 30% by mass to 75% by mass from the viewpoint of obtaining a large charge / discharge capacity.

The polythienoacene compound is a compound having a sulfur-containing polythienoacene structure represented by the general formula (8).

(In the formula, * represents a bond.)

The polythienoacene compound is a compound obtained by heat-treating an aliphatic polymer having a linear structure such as polyethylene, a polymer having a thiophene structure such as polythiophene, and elemental sulfur in a non-oxidizing atmosphere. The temperature of the heat treatment is preferably 300 ° C. to 600 ° C. The sulfur content of the polythienoacene compound is preferably 30% by mass to 80% by mass from the viewpoint of obtaining a large charge / discharge capacity.

The sulfur-modified polyamide compound is a compound having a carbon skeleton derived from a polymer having an amide bond. Specifically, an aminocarboxylic acid compound and elemental sulfur, or a polyamine compound and a polycarboxylic acid compound and elemental sulfur are non-oxidizing. It is a compound obtained by heat treatment in an atmosphere. The temperature of the heat treatment is preferably 250 ° C. to 600 ° C. The sulfur content of the sulfur-modified polyamide compound is preferably 40% by mass to 70% by mass from the viewpoint of obtaining a large charge / discharge capacity.

Polycarbon sulfide is a compound represented by the general formula (CS _x ) _n (x is 0.5 to 2 and n represents a number of 4 or more), and is, for example, an alkali metal sulfide such as sodium sulfide. It can be obtained by heat-treating a precursor obtained by reacting a composite of elemental sulfur with a halogenated unsaturated hydrocarbon such as hexachlorobutadiene. The temperature of the heat treatment is preferably 300 ° C. to 450 ° C. The sulfur content of the polysulfide carbon compound is preferably 65% by mass to 75% by mass from the viewpoint of obtaining a large charge / discharge capacity.

During the heat treatment, in addition to the materials, graphite-based carbon materials such as natural graphite, artificial graphite, and expanded graphite, carbon materials such as carbon black, nanocarbon, activated carbon, carbon fiber, coke, soft carbon, and hard carbon, and carbon materials such as hard carbon, A sulfide accelerator such as tetramethylthium disulfide, tetraethyl thiuram disulfide, tetrabutyl thiuram disulfide, tetrakis (2-ethylhexyl) thiuram disulfide, tetramethyl thiuram monosulfide, and dipentamethylene thiuram tetrasulfide can be used.
These may be used alone or in combination of two or more. The carbon material and the vulcanization accelerator can be blended in a known blending formula with a known blending ratio.

The shapes of the sulfur-carbon complex and the sulfur-modified organic compound are not particularly limited, but are, for example, spherical, polyhedral, fibrous, rod-shaped, plate-shaped, scaly, or amorphous, and these are hollow. It doesn't matter. Among these, a spherical or polyhedral shape is preferable because the electrode mixture layer is uniformly formed.

The sulfur content of the sulfur-carbon complex and the sulfur-modified organic compound can be measured using, for example, a CHN analyzer capable of analyzing sulfur and oxygen, for example, a vario MICRO cube manufactured by Elementer.

If the particle size of the positive electrode active material is too large, a uniform and smooth electrode mixture layer may not be obtained, while if it is too small, the handleability in the slurrying process deteriorates. Therefore, the average particles of the positive electrode active material are average particles. The diameter (D50) is preferably 0.5 μm to 100 μm, more preferably 1 μm to 50 μm, and even more preferably 1 μm to 30 μm.

In the present invention, the average particle size (D50) means a 50% particle size measured by a laser diffracted light scattering method. The particle diameter is a volume-based diameter, and the diameter of secondary particles is measured by the laser diffracted light scattering method.

The positive electrode active material can have a desired particle size by a method such as pulverization or granulation. The pulverization may be a dry pulverization performed in a gas or a wet pulverization performed in a liquid such as water. Examples of the industrial crushing method include a ball mill, a roller mill, a turbo mill, a jet mill, a cyclone mill, a hammer mill, a pin mill, a rotary mill, a vibration mill, a planetary mill, an attritor, and a bead mill.

In the battery of the present invention, a known binder can be used. Specific examples of the binder include styrene-butadiene rubber, butadiene rubber, acrylonitrile-butadiene rubber, ethylene-propylene-diene rubber, styrene-isoprene rubber, fluororubber, polyethylene, polypropylene, polyacrylamide, polyamide, polyamideimide, and polyimide. Polyacrylonitrile, polyurethane, polyvinylidene fluoride, polytetrafluoroethylene, styrene-acrylic acid ester copolymer, ethylene-vinyl alcohol copolymer, polymethylmethacrylate, polyacrylate, polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, polyvinyl ether, Examples thereof include polyvinyl chloride, acrylic acid, polyacrylic acid, methyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, cellulose nanofibers, starch and the like. These binders may be used alone or in combination of two or more.

The content of the binder is preferably 0.5 parts by mass to 30 parts by mass, and more preferably 1 part by mass to 20 parts by mass with respect to 100 parts by mass of the positive electrode active material.

In the battery of the present invention, as the conductive auxiliary agent, a known conductive auxiliary agent for the electrode can be used. Specific examples of conductive auxiliaries include natural graphite, artificial graphite, coal tar pitch, carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, roller black, disc black, and carbon. Carbon materials such as nanotubes, vapor grown carbon fiber (VGCF), flaky graphite, graphene, fullerene, needle coke; metal powders such as aluminum powder, nickel powder, titanium powder; zinc oxide, titanium oxide, etc. Conductive metal oxides of: La ₂ S ₃ , Sm ₂ S ₃ , Ce ₂ S ₃ , TiS _{2 and} other sulfides.

The average particle size (D50) of the conductive auxiliary agent is preferably 0.0001 μm to 100 μm, and more preferably 0.01 μm to 50 μm.

The content of the conductive auxiliary agent is usually 0.1 part by mass to 50 parts by mass, preferably 0.5 part by mass to 30 parts by mass, and 1 part by mass to 1 part by mass with respect to 100 parts by mass of the electrode active material. More preferably, it is 20 parts by mass.

In the battery of the present invention, examples of the solvent for preparing the positive electrode mixture paste include propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, 1,2-dimethoxyethane, 1,2-di. Ethoxyethane, acetonitrile, propionitrile, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, 1,3-dioxolane, nitromethane, N-methylpyrrolidone, N, N-dimethylformamide, dimethylacetamide, methylethylketone, cyclohexanone, methyl acetate, acrylic acid Examples thereof include methyl, diethyltriamine, N, N-dimethylaminopropylamine, polyethylene oxide, tetrahydrofuran, dimethyl sulfoxide, sulfolane, γ-butyrolactone, water, alcohol and the like.

The amount of the solvent used can be adjusted according to the coating method selected when coating the electrode mixture paste. For example, in the case of coating by the doctor blade method, the total of the positive electrode active material, the binder and the conductive auxiliary agent. The amount is preferably 15 parts by mass to 300 parts by mass, and more preferably 30 parts by mass to 200 parts by mass with respect to 100 parts by mass.

The positive electrode mixture paste contains, for example, other components such as a viscosity regulator, a reinforcing material, an antioxidant, a pH adjuster, and a dispersant, in addition to the above components, as long as the effects of the present invention are not impaired. You may let me. As these other components, known ones can be used in known compounding ratios.

In the production of the electrode mixture paste, when the positive electrode active material, the binder and the conductive additive are dispersed or dissolved in the solvent, all of them may be added to the solvent at once for dispersion treatment, or they may be added separately for dispersion treatment. You may. It is preferable to sequentially add the binder, the conductive auxiliary agent, and the positive electrode active material to the solvent in this order to perform the dispersion treatment because these can be uniformly dispersed in the solvent. When the electrode mixture paste contains other components, the other components can be added all at once for dispersion treatment, but it is preferable to perform dispersion treatment for each addition of one of the other components.

The method of dispersion treatment is not particularly limited, but industrial methods include, for example, ordinary ball mills, sand mills, bead mills, cyclone mills, pigment dispersers, grinders, ultrasonic dispersers, homogenizers, rotation / revolution mixers, and the like. Planetary mixers, fill mixes, jet pacers, etc. can be used.

In the battery of the present invention, a conductive material such as titanium, titanium alloy, aluminum, aluminum alloy, nickel, stainless steel, nickel-plated steel, or carbon is used as the current collector. Examples of the shape of the current collector include a foil shape, a plate shape, a net shape, a foam shape, a non-woven fabric shape, and the like, and the current collector may be either porous or non-porous. In addition, these conductive materials may be surface-treated in order to improve adhesion and electrical properties. Among these conductive materials, aluminum is preferable from the viewpoint of conductivity and price, and aluminum foil is particularly preferable. The thickness of the current collector is not particularly limited, but is usually 5 μm to 30 μm.

The method of applying the electrode mixture paste of the positive electrode onto the current collector is not particularly limited, but for example, the die coater method, the comma coater method, the curtain coater method, the spray coater method, the gravure coater method, the flexo coater method, and the knife coater. A method, a doctor blade method, a reverse roll method, a brush coating method, a dip method, or the like can be used. The die coater method, the knife coater method, the doctor blade method and the comma coater method are preferable in that a good surface condition of the coating layer can be obtained according to the viscosity and the drying property of the electrode mixture paste.

The positive electrode mixture paste may be applied to the current collector on one side or both sides of the current collector. When it is applied to both sides of the current collector, it may be applied sequentially on one side at a time, or it may be applied on both sides at the same time. Further, it may be applied continuously to the surface of the current collector, may be applied intermittently, or may be applied in a striped shape. The thickness, length and width of the coating layer can be appropriately determined according to the size of the battery and the like.

The method for drying the positive electrode mixture paste applied on the current collector is not particularly limited, and a known method can be used. Examples of the drying method include drying with warm air, hot air, and low humidity air, vacuum drying, standing in a heating furnace, and drying by irradiating far infrared rays, infrared rays, electron beams, or the like. These drying methods may be carried out in combination. The temperature at the time of heating is generally about 50 ° C. to 180 ° C., but conditions such as temperature can be appropriately set according to the coating amount of the electrode mixture paste, the boiling point of the solvent used, and the like. By this drying, volatile components such as a solvent are volatilized from the coating film of the electrode mixture paste, and an electrode mixture layer is formed on the current collector.

When a material containing no lithium is used as the positive electrode active material, lithium can be pre-doped in the positive electrode active material. The method for doping the material may be a known method. For example, a semi-battery is assembled using metallic lithium as the counter electrode, and lithium is inserted by the electrolytic doping method in which lithium is electrochemically doped, or a metallic lithium foil is attached to an electrode and then left in an electrolytic solution. Then, a method of inserting lithium by a pasting doping method of doping using the diffusion of lithium to an electrode, a mechanical doping method of mechanically colliding a positive electrode active material with a lithium metal and inserting lithium, and the like can be mentioned. However, the battery of the present invention is not limited to these methods.

The negative electrode used in the battery of the present invention can be manufactured according to a known method. For example, an electrode mixture paste containing a negative electrode active material, a binder and a conductive auxiliary agent is applied to a current collector and dried by applying an electrode mixture paste slurryed with an organic solvent or water to the electrode mixture on the current collector. A layered negative electrode can be manufactured.

A known negative electrode active material can be used. Known negative electrode active materials include, for example, natural graphite, artificial graphite, carbon-resistant carbon, easily graphitized carbon, lithium, lithium alloy, silicon, silicon alloy, silicon oxide, tin, tin alloy, tin oxide, phosphorus, germanium. , Indium, copper oxide, antimony sulfide, titanium oxide, iron oxide, manganese oxide, cobalt oxide, nickel oxide, lead oxide, ruthenium oxide, tungsten oxide, zinc oxide, LiVO ₂ , Li ₂ VO ₄ , Li ₄ Ti ₅ O _12, include composite oxides such as Chitan'niobu oxide. Only one kind of these negative electrode active materials may be used, or two or more kinds may be used in combination.

As an anode active material, sulfur, sulfur-modified organic compounds, sulfur - may carbon _composite, also be used _{Li 2 S x (x = 1~8} ). As the sulfur, sulfur-carbon composite and sulfur-modified organic compound, the same sulfur, sulfur-carbon composite and sulfur-modified organic compound described as the positive electrode active material can be used as the negative electrode active material.

If the particle size of the negative electrode active material is too large, a uniform and smooth electrode mixture layer may not be obtained, while if it is too small, the handleability in the slurrying process deteriorates. Therefore, the average particles of the negative electrode active material are average particles. The diameter (D50) is preferably 0.01 μm to 100 μm, more preferably 0.5 μm to 50 μm, and even more preferably 1 μm to 30 μm.

The negative electrode active material can have a desired particle size by a method such as pulverization or granulation. The pulverization may be a dry pulverization performed in a gas or a wet pulverization performed in a liquid such as water. Examples of the industrial crushing method include a ball mill, a roller mill, a turbo mill, a jet mill, a cyclone mill, a hammer mill, a pin mill, a rotary mill, a vibration mill, a planetary mill, an attritor, and a bead mill.

In the battery of the present invention, a known binder can be used. Specific examples of the binder include the same binders described as the binder used for the positive electrode. Only one kind of binder may be used, or two or more kinds of binders may be used in combination.

The content of the binder is preferably 1 part by mass to 30 parts by mass, and more preferably 1 part by mass to 20 parts by mass with respect to 100 parts by mass of the negative electrode active material.

In the battery of the present invention, as the conductive auxiliary agent, a known conductive auxiliary agent for the electrode can be used. Specific examples of the conductive auxiliary agent include the same conductive auxiliary agents used for the positive electrode.

The average particle size (D50) of the conductive auxiliary agent is preferably 0.0001 μm to 100 μm, and more preferably 0.01 μm to 50 μm.

The content of the conductive auxiliary agent is usually 0 parts by mass to 50 parts by mass, preferably 0 parts by mass to 30 parts by mass, and 0.5 parts by mass to 20 parts by mass with respect to 100 parts by mass of the electrode active material. It is more preferable that it is a part.

In the battery of the present invention, examples of the solvent for preparing the electrode mixture paste for the negative electrode include the same solvents as those used for preparing the electrode mixture paste for the positive electrode. The amount of the solvent used can be adjusted according to the coating method selected when coating the electrode mixture paste. For example, in the case of coating by the doctor blade method, the total of the negative electrode active material, the binder and the conductive auxiliary agent. The amount is preferably 15 parts by mass to 300 parts by mass, and more preferably 30 parts by mass to 200 parts by mass with respect to 100 parts by mass.

The electrode mixture paste for the negative electrode contains, for example, other components such as a viscosity regulator, a reinforcing material, an antioxidant, a pH adjuster, and a dispersant, in addition to the above components, as long as the effects of the present invention are not impaired. You may let me. As these other components, known ones can be used in known compounding ratios.

The negative electrode mixture paste can be produced by blending, dispersing and producing in the same process as the production process of the positive electrode mixture paste, except that the negative electrode active material is used instead of the positive electrode active material.

In the battery of the present invention, a conductive material such as titanium, titanium alloy, aluminum, aluminum alloy, copper, nickel, stainless steel, nickel-plated steel, and carbon is used as the current collector. Examples of the shape of the current collector include a foil shape, a plate shape, a net shape, a foam shape, a non-woven fabric shape, and the like, and the current collector may be either porous or non-porous. In addition, these conductive materials may be surface-treated in order to improve adhesion and electrical properties. Among these conductive materials, copper is preferable from the viewpoint of stability at the negative electrode potential, conductivity, and price, and copper foil is particularly preferable. The thickness of the current collector is not particularly limited, but is usually 3 μm to 30 μm.

When the negative electrode active material is a metal or metal alloy such as lithium, lithium alloy, tin, tin alloy, the electrode mixture paste is not prepared using a binder, a conductive auxiliary agent, or a solvent, and the metal or alloy is made into a plate, for example. It can also be used in the form of a sheet, a film, or the like. Further, when the alloy is used as the negative electrode active material, it is not necessary to use a current collector because the negative electrode active material itself has high electron conductivity, but depending on the convenience of the battery configuration, an alloy is formed with the negative electrode active material. It is also possible to use a metal material that does not have a negative electrode as a negative electrode current collector.

The method of applying the electrode mixture paste of the negative electrode onto the current collector is not particularly limited, and examples thereof include a coating method used when manufacturing a positive electrode.

The negative electrode mixture paste may be applied to the current collector on one side or both sides of the current collector. When it is applied to both sides of the current collector, it may be applied sequentially on one side at a time, or it may be applied on both sides at the same time. Further, it may be applied continuously to the surface of the current collector, may be applied intermittently, or may be applied in a striped shape. The thickness, length and width of the coating layer can be appropriately determined according to the size of the battery and the like.

The method for drying the electrode mixture paste of the negative electrode coated on the current collector is not particularly limited, and a known method can be used. Examples of the drying method include drying with warm air, hot air, and low humidity air, vacuum drying, standing in a heating furnace, and drying by irradiating far infrared rays, infrared rays, electron beams, or the like. These drying methods may be carried out in combination. The temperature at the time of heating is generally about 50 ° C. to 180 ° C., but conditions such as temperature can be appropriately set according to the coating amount of the electrode mixture paste, the boiling point of the solvent used, and the like. By this drying, volatile components such as a solvent are volatilized from the coating film of the electrode mixture paste, and an electrode mixture layer is formed on the current collector.

When a material having a large initial irreversible reaction, such as silicon-based, tin-based, or sulfur-based, is used as the negative electrode active material, lithium can be doped in advance. The method for doping the material may be a known method. For example, a semi-battery is assembled using metallic lithium as the counter electrode, and lithium is inserted by the electrolytic doping method in which lithium is electrochemically doped, or a metallic lithium foil is attached to an electrode and then left in an electrolytic solution. Then, a method of inserting lithium by a pasting doping method of doping using the diffusion of lithium to an electrode, a mechanical doping method of mechanically colliding a negative electrode active material with a lithium metal and inserting lithium, and the like can be mentioned. However, the battery of the present invention is not limited to these methods.

As the separator, a commonly used polymer film, glass film or the like can be used without particular limitation. Specific examples of the polymer film include polyethylene, polypropylene, polyvinylidene fluoride, polyvinylidene chloride, polyacrylonitrile, polyacrylamide, polytetrafluoroethylene, polysulfone, polyether sulfone, polycarbonate, polyamide, polyimide, polyethylene oxide and polypropylene. Polymer compounds and derivatives mainly composed of polyethers such as oxides, various celluloses such as carboxymethyl cellulose and hydroxypropyl cellulose, poly (meth) acrylic acid and various esters thereof, and copolymers thereof. Examples thereof include films made of a mixture, and these films may be coated with a ceramic material such as alumina or silica, magnesium oxide, an aramid resin, or polyvinylidene chloride. These films can be used alone, or these polymer films can be superposed and used as a multi-layer film. Further, various additives can be used for these polymer films, and the type and content thereof are not particularly limited. Among these polymer films, a film made of polyethylene, polypropylene, polyvinylidene fluoride, or polysulfone is preferably used.

These polymer films are microporous so that non-aqueous electrolytes can penetrate and ions can easily permeate. The microporous method includes a "phase separation method" in which a solution of a polymer compound and a solvent is microphase-separated to form a film, and the solvent is extracted and removed to make the polymer porous, and a high draft of the molten polymer compound. The "stretching method", in which the crystals are extruded and then heat-treated to arrange the crystals in one direction and then stretched to form gaps between the crystals to make them porous, is appropriately selected depending on the polymer film used. NS.

The shape of the non-aqueous electrolyte secondary battery of the present invention is not particularly limited, and can be a battery having various shapes such as a coin type battery, a cylindrical type battery, a square type battery, and a laminated type battery. FIG. 1 is a vertical cross-sectional view schematically showing an example of the structure of a coin-type non-aqueous electrolyte battery of the non-aqueous electrolyte secondary battery of the present invention. FIG. 2 is a schematic view showing a basic configuration of a cylindrical non-aqueous electrolyte battery of the non-aqueous electrolyte secondary battery of the present invention. FIG. 3 is a perspective view showing the internal structure of the cylindrical non-aqueous electrolyte battery of the non-aqueous electrolyte secondary battery of the present invention as a cross section.

The coin-type non-aqueous electrolyte secondary battery 10 shown in FIG. 1 includes a positive electrode current collector 1a, a positive electrode mixture layer 1 formed on the positive electrode current collector 1a and capable of emitting lithium ions, a positive electrode current collector 1a, and a positive electrode current collector 1a. A positive electrode case 4 for accommodating a positive electrode composed of a positive electrode mixture layer 1, a negative electrode current collector 2a, and a lithium ion formed on the negative electrode current collector 2a and released from the positive electrode mixture layer 1 are stored and released. A negative electrode mixture layer 2 that can be formed, a negative electrode case 5 that houses a negative electrode composed of a negative electrode current collector 2a and a negative electrode mixture layer 2, and a separator 7 are provided. The inside of the positive electrode case 4 and the negative electrode case 5 is filled with the non-aqueous electrolyte 3. Further, the peripheral portions of the positive electrode case 4 and the negative electrode case 5 are sealed by being crimped via a polypropylene gasket 6.

In the cylindrical non-aqueous electrolyte secondary battery 10'shown in FIGS. 2 and 3, an electrode body in which a negative electrode plate 19 and a positive electrode plate 21 are wound via a separator 7, a case 23 accommodating the electrode body, and a case 23 are included. It includes a pair of insulating plates 24 arranged so as to sandwich the electrode body. The positive electrode plate 21 is composed of a positive electrode current collector 1a and a positive electrode mixture layer 1 formed on the positive electrode current collector 1a and capable of emitting lithium ions. The negative electrode plate 19 is composed of a negative electrode current collector 2a and a negative electrode mixture layer 2 formed on the negative electrode current collector 2a and capable of storing and releasing lithium ions released from the positive electrode mixture layer 1. The inside of the case 23 is filled with the non-aqueous electrolyte 3. At the open end of the case 23, the positive electrode terminal 17, the safety valve 26 provided inside the positive electrode terminal 17, and the PTC (Positive Temperature Coefficient) element 27 are sealed by being crimped via the gasket 6. The negative electrode plate 19 is connected to the negative electrode terminal 18 via the negative electrode lead 20. The positive electrode plate 21 is connected to the positive electrode terminal 17 via the positive electrode lead 22.

Examples of the exterior member used for the positive electrode case 4, the negative electrode case 5, and the case 23 include a metal container, a laminated film, and the like. The thickness of the exterior member is usually 0.5 mm or less, preferably 0.3 mm or less. Examples of the shape of the exterior member include a flat type (thin type), a square type, a cylindrical type, a coin type, and a button type.

The metal container can be formed from, for example, stainless steel, aluminum, an aluminum alloy, or the like. As the aluminum alloy, an alloy containing elements such as magnesium, zinc, and silicon is preferable. By reducing the content of transition metals such as iron, copper, nickel, and chromium to 1% by mass or less in aluminum or aluminum alloy, long-term reliability and heat dissipation in a high temperature environment can be dramatically improved. ..

As the laminate film, a multilayer film having a metal layer between resin films can be used. The metal layer is preferably an aluminum foil or an aluminum alloy foil for weight reduction. As the resin film, for example, a polymer material such as polypropylene, polyethylene, nylon, or polyethylene terephthalate can be used. The laminated film can be sealed by heat fusion to form an exterior member.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. As long as it does not deviate from the gist of the present invention, it can be carried out in various forms with modifications, improvements, etc. that can be made by those skilled in the art.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to these examples.

<Preparation of positive electrode A>
_{90.0 parts by mass of NCM111 (LiNi 1/3} Co _1/3 Mn _1/3 O ₂ , manufactured by Aldrich) as the positive electrode active material, and 5.0 of acetylene black (Denka Black, manufactured by Denka) as the conductive auxiliary agent. Using 5.0 parts by mass of polyvinylidene fluoride (manufactured by Kureha) as a binder and 90 parts by mass of N-methylpyrrolidone as a solvent, the mixture was dispersed using a planetary mixer to obtain a slurry-like electrode mixture paste. rice field. This electrode mixture paste was applied to one side of a current collector made of aluminum foil (thickness 15 μm) by the doctor blade method, dried at 90 ° C., and then press-molded. Then, the electrode was cut to a predetermined size, and immediately before use, it was vacuum dried at 130 ° C. for 3 hours to prepare a positive electrode A.

<Manufacturing of negative electrode A>
97.3 parts by mass of artificial graphite (MAGD, manufactured by Hitachi Kasei Co., Ltd.) as the negative electrode active material, 1.45 parts by mass of styrene-butadiene rubber (40% by mass aqueous dispersion, manufactured by Nippon Zeon Co., Ltd.) as the binder, sodium carboxymethyl cellulose. Using 1.225 parts by mass of (CMCNa, manufactured by Daicel FineChem) and 120 parts by mass of water as a solvent, the mixture was dispersed using a planetary mixer to obtain a slurry-like electrode mixture paste. This electrode mixture paste was applied to one side of a current collector made of copper foil (thickness 10 μm) by the doctor blade method, dried at 90 ° C., and then press-molded. Then, the electrode was cut to a predetermined size, and immediately before use, it was vacuum dried at 130 ° C. for 3 hours to prepare a negative electrode A.

<Battery production-1>
[Example 1]
_{A solution was prepared in which LiPF 6} as a supporting electrolyte was dissolved at a concentration of 1.0 mol / L in a mixed solvent consisting of 50% by volume of ethylene carbonate and 50% by volume of diethyl carbonate. Compound 1-1 was added thereto in an amount of 1.0% by mass to prepare a non-aqueous electrolyte.
A positive electrode A cut into a disk shape and a negative electrode A cut into a disk shape were used, and a polypropylene film (manufactured by Celgard) was sandwiched as a separator and held in the case. Then, the non-aqueous electrolyte prepared above was injected into the case and sealed with a caulking machine to prepare a non-aqueous electrolyte secondary battery (φ20 mm, thickness 3.2 mm, coin type) of Example 1.

[Examples 2 to 16]
The non-aqueous electrolyte secondary batteries of Examples 2 to 16 were prepared in the same manner as in Example 1 except that the compounds shown in Table 1 were added to the non-aqueous electrolyte instead of Compound 1-1.

[Comparative Examples 1 to 4]
The non-aqueous electrolyte secondary batteries of Comparative Examples 1 to 4 were produced in the same manner as in Example 1 except that the compounds shown in Table 1 were added to the non-aqueous electrolyte instead of Compound 1-1. As the added compounds 7-1 to 7-4, the compounds shown below were used.

[Comparative Example 5]
The non-aqueous electrolyte secondary battery of Comparative Example 5 was produced by the same operation as in Example 1 except that Compound 1-1 was not added.

<Charge / discharge evaluation>
The non-aqueous electrolyte secondary batteries of Examples 1 to 16 and Comparative Examples 1 to 5 were placed in a constant temperature bath at 25 ° C., the end-of-charge voltage was 4.20 V, the end-of-discharge voltage was 2.75 V, and the charge rate was 0.2 C. The charge / discharge test at a discharge rate of 0.2 C was performed 5 times, and the charge / discharge test at a charge rate of 2C and a discharge rate of 2C was performed 5 times. After that, it was placed in a constant temperature bath at 45 ° C., and a total of 110 charge / discharge tests were performed at a charge rate of 0.5 C and a discharge rate of 0.5 C, for a total of 110 times, and the discharge capacity (mAh / g) per positive electrode active material was measured. .. The ratio of the 110th discharge capacity to the 11th discharge capacity was calculated as the discharge capacity ratio L1 (L1 = 110th discharge capacity ÷ 11th discharge capacity × 100).
Subsequently, 10 charge / discharge tests were performed at a charge rate of 2C and a discharge rate of 2C, and the rate characteristic R1 (R1 = 120th discharge capacity (2.0C) ÷ 110th discharge capacity (0.5C) × 100) was calculated. did.
Table 1 shows the evaluation results of the discharge capacity ratio (L1) and the rate characteristic (R1) of the non-aqueous electrolyte secondary batteries of Examples 1 to 16 and Comparative Examples 1 to 5.

From Comparative Examples 1 to 5 in Table 1, the non-aqueous electrolyte secondary battery different from the battery of the present invention had a low rate characteristic (R1) and was not satisfactory, whereas from Examples 1 to 16, The non-aqueous electrolyte secondary battery using the non-aqueous electrolyte of the present invention has good discharge capacity ratio (L1) and rate characteristics (R1) of 80% or more, and is particularly good as compared with Comparative Examples 1 to 5. It was confirmed that the non-aqueous electrolyte secondary battery using the non-aqueous electrolyte of the present invention shows a remarkable effect on the rate characteristic (R1).

1 Positive electrode mixture layer 1a Positive electrode current collector 2 Negative electrode mixture layer 2a Negative electrode current collector 3 Non-aqueous electrolyte 4 Positive electrode case 5 Negative electrode case 6 Gasket 7 Separator 10 Coin-type non-aqueous electrolyte secondary battery 10'Cylindrical non-aqueous Water electrolyte secondary battery 17 Positive electrode terminal 18 Negative electrode terminal 19 Negative electrode plate 20 Negative electrode lead 21 Positive electrode plate 22 Positive electrode lead 23 Case 24 Insulation plate 26 Safety valve 27 PTC element

Claims (9)

A non-aqueous electrolyte additive comprising a compound having a structure represented by the general formula (1) in the molecule.

(In the formula, R ^{1 to} R ³ independently represent a monovalent hydrocarbon group having 1 to 6 carbon atoms, and R ⁴ represents a divalent hydrocarbon group having 1 to 8 carbon atoms. Represented, * represents a bond. However, some hydrogen atoms of a monovalent or divalent hydrocarbon group may be substituted with a hydroxyl group.) The non-aqueous electrolyte additive according to claim 1, wherein the compound is a reaction product of trialkylchlorosilane and a carboxylic acid compound. The non-aqueous electrolyte additive according to claim 1 or 2, wherein the compound is selected from the group of compounds represented by the general formulas (2) to (7).

(In the formula, R ^{5 to} R ⁷ each independently represent the following Z, a hydrogen atom or a monovalent hydrocarbon group having 1 to 8 carbon atoms, but at least one of ^{R 5 to} R ^{7 is} It represents Z below. However, two of R ^{5 to} R ⁷ may be bonded to each other to form a ring, and hetero atoms (oxygen atom, nitrogen atom and sulfur atom) are contained in a monovalent hydrocarbon group. It may be contained, and some hydrogen atoms of the monovalent hydrocarbon group may be substituted with a hydroxyl group.)

(In the formula, R ^{8 to} R ¹⁰ each independently represent a monovalent hydrocarbon group having 1 to 6 carbon atoms, * represents a bond, and R ¹¹ represents a carbon atom number 1 to 8 Represents the divalent hydrocarbon group of, or is a direct bond between the carbon atom of the carbonyl group and the bond.)

(In the formula, R ^{12 to} R ¹⁵ each independently represent the Z, hydrogen atom or monovalent hydrocarbon group having 1 to 8 carbon atoms, but at least one of ^{R 12 to} R ^{15 is} Representing Z, R ¹⁶ represents a divalent hydrocarbon group having 1 to 8 carbon atoms or is a direct bond. However, ^{two or more of R 12 to} R ¹⁶ are bonded to each other to form a ring. It may be formed, or some hydrogen atoms of a monovalent or divalent hydrocarbon group may be substituted with a hydroxyl group.)

(In the formula, R ^{17 to} R ²¹ each independently represent the Z, hydrogen atom or monovalent hydrocarbon group having 1 to 8 carbon atoms, but at least one of ^{R 17 to} R ^{21 is} Representing Z, R ²² and R ²³ each independently represent a divalent hydrocarbon group having 1 to 8 carbon atoms or are directly bonded, except that two of ^{R 17 to} R ^23. The above may be bonded to each other to form a ring, or some hydrogen atoms of a monovalent or divalent hydrocarbon group may be substituted with a hydroxyl group.)

(In the formula, R ^{24 to} R ²⁸ independently represent the Z, hydrogen atom or monovalent hydrocarbon group having 1 to 8 carbon atoms, but at least one of ^{R 24 to} R ^{28 is} Represents Z)

(In the formula, R ^{29 to} R ³⁶ independently represent the Z, hydrogen atom or monovalent hydrocarbon group having 1 to 8 carbon atoms, but at least one of ^{R 29 to} R ^{36 is} Represents Z)

(In the formula, R ^{37 to} R ⁴² independently represent a hydrogen atom or a monovalent hydrocarbon group ^{having 1 to 6 carbon atoms, and R 43} is a monovalent hydrocarbon having 1 to 6 carbon atoms. It represents a hydrogen group, a monovalent hydrocarbon group or a cyano group having 1 to 6 carbon atoms in which some or all of the hydrogen atoms are replaced with fluorine atoms.) The non-aqueous electrolyte additive according to claim 3, wherein all ^{of R 5 to} R ⁷ in the general formula (2) represent Z. The non-aqueous electrolyte additive according to claim 3, wherein two ^{of R 5 to} R ⁷ in the general formula (2) represent Z. ^{The non-aqueous electrolyte additive according to claim 3, wherein R 16} in the general formula (3) represents a methanediyl group, an ethanediyl group, a propanediyl group or a benzenediyl group. The non-aqueous electrolyte additive according to claim 3, wherein all ^{of R 12 to} R ¹⁵ in the general formula (3) represent the Z. The non-aqueous electrolyte additive according to any one of claims 1 to 7, and the non-aqueous electrolyte additive.
At least one selected from the group consisting of a solvent and a dispersion medium, and
A non-aqueous electrolyte containing a supporting electrolyte,
A non-aqueous electrolyte containing 0.01% by mass to 20% by mass of the non-aqueous electrolyte additive. With the positive electrode
With the negative electrode
A non-aqueous electrolyte secondary battery containing the non-aqueous electrolyte according to claim 8.

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