JP2018142556A - Nonaqueous electrolytic solution and nonaqueous electrolytic solution battery using them - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide nonaqueous electrolytic solution having excellent durability, capacity, resistance, and output characteristics or the like for a lithium nonaqueous electrolytic solution secondary battery.SOLUTION: There is provided nonaqueous electrolytic solution for a nonaqueous electrolytic solution battery that comprises a positive electrode and a negative electrode capable of storing and releasing a metal ion. The nonaqueous electrolytic solution contains: an electrolyte and a nonaqueous solvent; a specified isocyanuric acid derivative; and (1) at least one kind compound selected from the group consisting of a nitryl compound, an isocyanate compound, a difluorophosphate, a fluorosulfonate, a lithium bis(fluorosulfonyl)imide, and a compound expressed by the following general formula (B), further contains a cyclic carbonate compound (2) having fluorine atom in an amount of 0.01-50.0 wt.% of the total amount of the nonaqueous electrolytic solution.SELECTED DRAWING: None

Description

  The present invention relates to a non-aqueous electrolyte and a non-aqueous electrolyte battery using the same.

With the rapid progress of portable electronic devices such as mobile phones and notebook personal computers, there is an increasing demand for higher capacities for batteries used for the main power source and backup power source, such as nickel cadmium batteries and nickel Non-aqueous electrolyte batteries such as lithium ion secondary batteries having higher energy density than hydrogen batteries have attracted attention.
Examples of the electrolyte solution for the lithium ion secondary battery include LiPF ₆ , LiBF ₄ , LiN (CF ₃
SO ₂ ) ₂ , LiCF ₃ (CF ₂ ) ₃ SO _{3 and} other electrolytes are mixed solvents of high dielectric constant solvents such as ethylene carbonate and propylene carbonate and low viscosity solvents such as dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate. A typical example is a non-aqueous electrolyte solution dissolved in the solution.

In addition, as a negative electrode active material of a lithium ion secondary battery, a carbonaceous material capable of occluding and releasing lithium ions is mainly used, and natural graphite, artificial graphite, amorphous carbon, etc. are listed as representative examples. It is done. Furthermore, metal or alloy negative electrodes using silicon, tin or the like for increasing the capacity are also known. As the positive electrode active material, a transition metal composite oxide capable of mainly inserting and extracting lithium ions is used, and representative examples of the transition metal include cobalt, nickel, manganese, iron and the like.

Such a lithium ion secondary battery uses a highly active positive electrode and negative electrode, and it is known that the charge / discharge capacity decreases due to a side reaction between the electrode and the electrolyte, improving battery characteristics. Therefore, various studies have been made on non-aqueous solvents and electrolytes.
Patent Document 1 attempts to improve battery storage characteristics by adding a tricarbimide compound such as triallyl cyanurate or triallyl isocyanurate to a nonaqueous electrolytic solution.

In Patent Document 2, by dissolving a low molecular weight isocyanate compound in an organic electrolyte,
It has been reported that a reaction layer can be formed at the electrode interface to obtain excellent cycle stability.
In Patent Document 3, by using an electrolytic solution to which an organic compound having two or more nitrile groups is added, a large dipole moment due to polarization of the nitrile group causes an oxidative decomposition of the electrolytic solution on the positive electrode during charging at a high voltage. It has been proposed that battery characteristics are improved thereby.

Patent Document 4 reports that the high-temperature storage characteristics, input / output characteristics, and impedance characteristics of a battery are improved by using an electrolytic solution to which lithium fluorosulfonic acid salt is added.
Patent Document 5 reports that the high-temperature storage characteristics of a battery are improved by using an electrolyte added with lithium fluorophosphate.

Patent Documents 6 and 7 report that the addition of a phosphite compound and triallyl cyanurate or triallyl isocyanurate to a non-aqueous electrolyte improves the cycle characteristics and the safety of the electrolyte. .

Japanese Patent Laid-Open No. 7-192757 Japanese Unexamined Patent Publication No. 2000-268859 Japanese Unexamined Patent Publication No. 7-176322 Japanese Unexamined Patent Publication No. 2011-187440 Japanese Unexamined Patent Publication No. 11-67270 Japanese Unexamined Patent Publication No. 2010-282906 International Publication WO2008 / 50599

However, the demand for improving the characteristics of lithium non-aqueous electrolyte secondary batteries in recent years is increasing, and all the performances such as high-temperature storage characteristics, energy density, output characteristics, life, high-speed charge / discharge characteristics, and low-temperature characteristics Although it is required to have a high level, it has not yet been achieved. The durability performance including high temperature storage characteristics and the performance such as capacity, resistance, and output characteristics are in a trade-off relationship.

The present invention has been made in view of the above-described problems. That is, with respect to a lithium non-aqueous electrolyte secondary battery, an object is to provide a battery having a good balance of overall performance with respect to performance such as durability and capacity, resistance, and output characteristics.

The inventors of the present invention have intensively studied to achieve the above object, and as a result, the compound containing the structure represented by the formula (A), (1) a nitrile compound, an isocyanate compound, a difluorophosphate, A non-aqueous electrolyte containing at least one compound selected from the group consisting of a fluorosulfonate, lithium bis (fluorosulfonyl) imide and a compound represented by the following general formula (B), or ( 2) It has been found that the above-mentioned problems can be solved by containing 0.01 to 50.0% by weight of a cyclic carbonate compound having a fluorine atom with respect to the total amount of the nonaqueous electrolytic solution, and the present invention has been completed.
A non-aqueous electrolyte solution for a non-aqueous electrolyte battery comprising a positive electrode and a negative electrode capable of occluding and releasing metal ions, the non-aqueous electrolyte solution being represented by the following general formula (A) together with an electrolyte and a non-aqueous solvent A compound containing a structure, and (1) selected from the group consisting of a nitrile compound, an isocyanate compound, a difluorophosphate, a fluorosulfonate, lithium bis (fluorosulfonyl) imide, and a compound represented by the following general formula (B) Containing at least one kind of compound, or (2) containing a cyclic carbonate compound having a fluorine atom in an amount of 0.01 to 50.0% by weight based on the total amount of the non-aqueous electrolyte. A non-aqueous electrolyte solution characterized by that.

(In formula (A), R _{1 to} R ₃ may be the same as or different from each other and have 1 to 2 carbon atoms.
It is an organic group which may have 0 substituents. )

(In Formula (B), R ₁ , R ₂ and R ₃ each independently represents an alkyl group, alkenyl group or alkynyl group having 1 to 12 carbon atoms which may be substituted with a halogen atom, and n represents 0
Represents an integer of ~ 6. )
A nonaqueous electrolytic solution in which at least one of R _{1 to} R ₄ is a hydrocarbon group having a carbon-carbon unsaturated bond in the general formula (A).

A non-aqueous electrolyte in which the hydrocarbon group having an unsaturated bond is an allyl group or a methallyl group.
The non-aqueous electrolyte solution in which the addition amount of the compound including the structure represented by the general formula (A) is 0.01% by weight or more and 10.0% by weight or less with respect to the total amount of the non-aqueous electrolyte solution.
The nitrile compound, isocyanate compound, difluorophosphate, fluorosulfonate, lithium bis (fluorosulfonyl) imide, and the compound represented by the following general formula (B) are 0.01% with respect to the total amount of the nonaqueous electrolytic solution. A non-aqueous electrolyte that is not less than 10.0% by weight.

The cyclic carbonate having a fluorine atom is monofluoroethylene carbonate, 4
The non-aqueous electrolyte solution according to any one of claims 1 to 3, which is at least one compound selected from the group consisting of 1,4-difluoroethylene carbonate and 4,5-difluoroethylene carbonate.
The non-aqueous electrolyte is at least one selected from the group consisting of a cyclic carbonate having a carbon-carbon unsaturated bond, an acid anhydride, a vinyl sulfonate ester, an aromatic compound having 12 or less carbon atoms, and a chain carboxylic ester. A non-aqueous electrolyte containing the compound of

A non-aqueous electrolyte secondary battery comprising a positive electrode capable of inserting and extracting lithium ions, a negative electrode capable of inserting and extracting lithium ions, and a non-aqueous electrolyte solution.
The negative electrode active material of a negative electrode capable of inserting and extracting lithium ions is a non-aqueous electrolyte battery having carbon as a constituent element.
The negative electrode active material of the negative electrode capable of inserting and extracting lithium ions is a non-aqueous electrolyte battery having silicon (Si) or tin (Sn) as a constituent element.

The negative electrode active material of the negative electrode capable of inserting and extracting lithium ions is a non-aqueous electrolyte battery that is a mixture or composite of particles and graphite particles containing silicon (Si) or tin (Sn) as constituent elements.
The content of particles having silicon (Si) or tin (Sn) as a constituent element with respect to the total of the particles having silicon (Si) or tin (Sn) as a constituent element and graphite particles is 0.1 to 25% by mass. A non-aqueous electrolyte battery.

ADVANTAGE OF THE INVENTION According to this invention, regarding a lithium non-aqueous electrolyte secondary battery, a battery with a good balance of overall performance can be provided with respect to performance such as durability, capacity, resistance, and output characteristics.
Action and principle that the non-aqueous electrolyte secondary battery manufactured using the non-aqueous electrolyte of the present invention and the non-aqueous electrolyte secondary battery of the present invention become a secondary battery with a good balance of overall performance. Is not clear, but is considered as follows. However, the present invention is not limited to the operations and principles described below.

It has been reported that the compounds described in Patent Documents 1 to 5 suppress the decomposition reaction of the electrolytic solution by acting on the positive electrode or the negative electrode of the battery and improve the high-temperature storage characteristics and cycle characteristics of the battery. However, most of the effects were only improved high-temperature storage characteristics, and the effects were not sufficient. In addition, the cycle characteristic improving effect described in Patent Document 2 is insufficient and is not satisfactory.

Patent Document 6 describes that a fluorinated cyclic carbonate such as fluoroethylene carbonate is used as the cyclic carbonate in the electrolytic solution, but the optimum amount is not clarified.

In order to solve the above problems, in the present invention, a compound containing a structure represented by the formula (A), and (1) a nitrile compound, an isocyanate compound, a difluorophosphate, a fluorosulfonate, lithium bis (fluorosulfonyl) ) At least one compound selected from the group consisting of an imide and a compound represented by the following general formula (B) is contained. As a result, it was found that not only the high-temperature storage characteristics but also the cycle characteristics and rate characteristics were improved, and the present invention was completed.

In order to solve the above problems, in the present invention, a compound containing a structure represented by the formula (A) and (2)
The cyclic carbonate compound having a fluorine atom is 0.01 to 5 with respect to the total amount of the non-aqueous electrolyte.
0.0% by weight is contained. As a result, an appropriate amount of the cyclic carbonate having a fluorine atom in the nonaqueous electrolytic solution was found, and the present invention was completed.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments, and can be arbitrarily modified and implemented without departing from the gist of the present invention.
Also, here, “wt%”, “wt ppm”, “parts by weight”, “mass%”, “mass pp”.
“m” and “parts by mass” are synonymous with each other.
“Weight ppm” is shown.

1. Non-aqueous electrolyte 1-1. Nonaqueous Electrolytic Solution of the Present Invention The nonaqueous electrolytic solution of the present invention includes a compound having a structure represented by the following general formula (A), a nitrile compound, an isocyanate compound, a difluorophosphate, a fluorosulfonate, lithium It is characterized by containing at least one compound selected from the group consisting of a compound represented by bis (fluorosulfonyl) imide and the following general formula (B).
1-1-1. Compound having structure represented by general formula (A)

In formula (A), R _{1 to} R ₃ may be the same as or different from each other, and have 1 to 2 carbon atoms.
It is an organic group which may have 0 substituents.
Here, the organic group represents a functional group composed of atoms selected from the group consisting of carbon atoms, hydrogen atoms, nitrogen atoms, oxygen atoms and halogen atoms. Specific examples include alkyl groups, alkenyl groups, alkynyl groups, aryl groups, alkoxy groups, nitrile groups, ether groups, carbonate groups, carbonyl groups, and the like.

Specific examples of the substituent include an alkyl group, alkenyl group, alkynyl group, aryl group, alkoxy group, nitrile group, ether group, carbonate group, carbonyl group, carboxyl group, sulfonyl group which may be substituted with a halogen atom. Group and phosphoryl group.
Specific examples of the alkyl group include, for example, linear or branched chain such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, and tert-butyl group. Examples thereof include cyclic alkyl groups such as alkyl groups or fluorine-substituted alkyl groups, cyclopropyl groups, cyclopentyl groups, and cyclohexyl groups.

Specific examples of the alkenyl group include vinyl group, allyl group, methallyl group, 1-propenyl group, fluorine-substituted vinyl group, allyl group, methallyl group, and alkyl group.
Specific examples of the alkynyl group include ethynyl group, propargyl group, 1-propynyl group and the like.
Specific examples of the aryl group include a phenyl group, a tolyl group, a benzyl group, and a phenethyl group.

Specific examples of the organic group which may have a substituent include an acrylic group, a methacryl group, an acrylic group via an alkyl group, a methacryl group, an epoxy group, a glycidyl group, a carbonyl group, a cyanoalkyl group, a vinylsulfonyl group, Examples thereof include a trimethylsilyl group and a trimethylsilyl group having an alkyl group.
Among these, a methyl group, an ethyl group, an i-propyl group, a tert-butyl group,
Cyclohexyl group, vinyl group, allyl group, methallyl group, ethynyl group, propargyl group, phenyl group, acrylic group, methacryl group, acrylic group via alkyl group, methacryl group, glycidyl group, carbonyl group, cyanoalkyl group, vinylsulfonyl Group, trimethylsilyl group, trimethylsilyl group having an alkyl group, fluorine-substituted alkyl group, fluorine-substituted vinyl group, alkyl group and the like.

More preferably, a cyclohexyl group, a vinyl group, an allyl group, a methallyl group, an ethynyl group,
Propagyl group, phenyl group, acrylic group, methacryl group, acrylic group via alkyl group, methacryl group, glycidyl group, cyanoalkyl group, vinylsulfonyl group, trimethylsilyl group, trimethylsilyl group having alkyl group, fluorine-substituted alkyl group , Fluorine-substituted vinyl groups, alkyl groups, and the like.

Particularly preferably, a cyclohexyl group, a vinyl group, an allyl group, a methallyl group, an ethynyl group,
Examples include propargyl group, acrylic group, methacryl group, acrylic group via alkyl group, methacryl group, carbonyl group, vinylsulfonyl group, trimethylsilyl group, trimethylsilyl group having alkyl group, fluorine-substituted vinyl group, alkyl group, etc. .
Most preferably, vinyl group, allyl group, methallyl group, ethynyl group, propargyl group, acrylic group via alkyl group, methacryl group, vinylsulfonyl group, glycidyl group, trimethylsilyl group, trimethylsilyl group having alkyl group, fluorine-substituted Vinyl group, alkyl group and the like. Among these, a group having a carbon-carbon unsaturated bond is preferable.
Specific examples of the compound include, for example,

  Among them, preferably

More preferably,

Particularly preferably,

Most preferably,

Is mentioned.
There is no limitation on the amount of the compound of the general formula (A) with respect to the entire non-aqueous electrolyte solution of the present invention, and it is optional as long as the effects of the present invention are not significantly impaired. 0
. 001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less,
More preferably, it is contained at a concentration of 2% by mass or less, particularly preferably 1% by mass or less, and most preferably 0.5% by mass or less.
When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, and high temperature storage characteristics are further improved.

1-1-2. Nitrile Compound The nitrile compound is not particularly limited as long as it is a compound having a nitrile group in the molecule.

Specific examples of nitrile compounds include, for example,
Acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeronitrile, isovaleronitrile, lauronitrile, 2-methylbutyronitrile, trimethylacetonitrile, hexanenitrile, cyclopentanecarbonitrile, cyclohexanecarbonitrile, acrylonitrile, methacrylonitrile , Crotononitrile, 3-methylcrotononitrile, 2-methyl-2-butenenitryl, 2-pentenenitrile, 2-methyl-2-pentenenitrile, 3-methyl-2-pentenenitrile, 2-hexenenitrile, Fluoroacetonitrile, difluoroacetonitrile, trifluoroacetonitrile,
2-fluoropropionitrile, 3-fluoropropionitrile, 2,2-difluoropropionitrile, 2,3-difluoropropionitrile, 3,3-difluoropropionitrile, 2,2,3-trifluoropropio Nitrile, 3,3,3-trifluoropropionitrile, 3,3′-oxydipropionitrile, 3,3′-thiodipropionitrile, 1,2,3-propanetricarbonitrile, 1,3,5- Compounds having one nitrile group such as pentanetricarbonitrile and pentafluoropropionitrile;
Malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimonitrile, suberonitrile, azeronitrile, sebacononitrile, undecandinitrile, dodecandinitrile, methylmalononitrile, ethylmalononitrile, isopropylmalononitrile, tert-butylmalononitrile, methylsuccinonitrile 2,2-dimethylsuccinonitrile, 2,3-dimethylsuccinonitrile, 2,3,3-trimethylsuccinonitrile, 2,2,3,3-tetramethylsuccinonitrile, 2,3-diethyl- 2,
3-dimethylsuccinonitrile, 2,2-diethyl-3,3-dimethylsuccinonitrile, bicyclohexyl-1,1-dicarbonitrile, bicyclohexyl-2,2-dicarbonitrile, bicyclohexyl-3,3 -Dicarbonitrile, 2,5-dimethyl-2,5-
Hexanedicarbonitrile, 2,3-diisobutyl-2,3-dimethylsuccinonitrile, 2,2-diisobutyl-3,3-dimethylsuccinonitrile, 2-methylglutaronitrile, 2,3-dimethylglutaronitrile 2,4-dimethylglutaronitrile, 2,2
, 3,3-tetramethylglutaronitrile, 2,2,4,4-tetramethylglutaronitrile, 2,2,3,4-tetramethylglutaronitrile, 2,3,3,4-tetramethylgluconitrile Talonitrile, maleonitrile, fumaronitrile, 1,4-dicyanopentane, 2,
6-dicyanoheptane, 2,7-dicyanooctane, 2,8-dicyanononane, 1,6-
Dicyanodecane, 1,2-didianobenzene, 1,3-dicyanobenzene, 1,4-dicyanobenzene, 3,3 ′-(ethylenedioxy) dipropionitrile, 3,3 ′-(ethylenedithio) dipropio Nitrile, 3,9-bis (2-cyanoethyl) -2,4,8,1
Compounds having two nitrile groups such as 0-tetraoxaspiro [5,5] undecane;
Compounds having three cyano groups such as cyclohexanetricarbonitrile, triscyanoethylamine, triscyanoethoxypropane, tricyanoethylene, pentanetricarbonitrile, propanetricarbonitrile, heptanetricarbonitrile;
Etc.

Among these, lauronitrile, crotononitrile, succinonitrile, glutaronitrile, adiponitrile, pimeonitrile, suberonitrile, azeronitrile, sebacononitrile, undecandinitrile, dodecandinitrile, fumaronitrile, 3,9-bis (2
-Cyanoethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane is preferred from the standpoint of improving storage properties. Also, succinonitrile, glutaronitrile, adiponitrile, pimeonitrile, suberonitrile, azeronitrile, sebacononitrile, undecandinitrile, dodecandinitrile, fumaronitrile, 3,9-bis (2-cyanoethyl)-
Particularly preferred are dinitrile compounds such as 2,4,8,10-tetraoxaspiro [5,5] undecane. Further, a chain dinitrile having 4 or more carbon atoms is preferable.

A nitrile compound may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. There is no limitation on the amount of the nitrile compound added to the whole non-aqueous electrolyte solution of the present invention, and it is optional as long as the effects of the present invention are not significantly impaired. Usually, 0.001% by mass with respect to the non-aqueous electrolyte solution of the present invention Or more, preferably 0.01% by mass or more, more preferably 0.1% by mass.
It is contained in a concentration of not less than 10% by weight, usually not more than 10% by weight, preferably not more than 5% by weight, more preferably not more than 3% by weight, still more preferably not more than 2% by weight, most preferably not more than 1% by weight. When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, and high temperature storage characteristics are further improved.

1-1-4. Isocyanate compound The type of the isocyanate compound is not particularly limited as long as it is a compound having an isocyanate group in the molecule.
Specific examples of the isocyanate compound include, for example,
Hydrocarbon monoisocyanate compounds such as methyl isocyanate, ethyl isocyanate, propyl isocyanate, isopropyl isocyanate, butyl isocyanate, tertiary butyl isocyanate, pentyl isocyanate, hexyl isocyanate, cyclohexyl isocyanate, phenyl isocyanate and fluorophenyl isocyanate;

Monoisocyanate compounds having a carbon-carbon unsaturated bond, such as vinyl isocyanate, allyl isocyanate, ethynyl isocyanate, propynyl isocyanate;
Monomethylene diisocyanate, dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, 1,3-diisocyanate Natopropane, 1,4-diisocyanato-2
-Butene, 1,4-diisocyanato-2-fluorobutane, 1,4-diisocyanato-2
, 3-difluorobutane, 1,5-diisocyanato-2-pentene, 1,5-diisocyanato-2-methylpentane, 1,6-diisocyanato-2-hexene, 1,6-diisocyanato-3-hexene, 1,6 -Diisocyanato-3-fluorohexane, 1,6-diisocyanato-3,4-difluorohexane, toluene diisocyanate, xylene diisocyanate, tolylene diisocyanate, 1,2-bis (isocyanatomethyl) cyclohexane, 1,3-bis (isocyanate) Natomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, 1,2-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane, dicyclohexylmethane-1,1 '-Diisocyanate DOO, dicyclohexylmethane-2,2'-diisocyanate, dicyclohexylmethane-3,3'-diisocyanate, dicyclohexylmethane -
4,4′-diisocyanate, bicyclo [2.2.1] heptane-2,5-diylbis (
Methyl isocyanate), bicyclo [2.2.1] heptane-2,6-diylbis (methyl isocyanate), isophorone diisocyanate, carbonyl diisocyanate, 1,4
-Diisocyanatobutane-1,4-dione, 1,5-diisocyanatopentane-1,5-
Hydrocarbon diisocyanate compounds such as dione, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate;
Isocyanate compounds such as diisocyanatosulfone, (ortho-, meta-, para-) toluenesulfonyl isocyanate, benzenesulfonyl isocyanate, fluorosulfonyl isocyanate, phenoxysulfonyl isocyanate, pentafluorophenoxysulfonyl isocyanate, methoxysulfonyl isocyanate;
Etc.

Among these, monoisocyanate compounds having a carbon-carbon unsaturated bond, such as vinyl isocyanate, allyl isocyanate, ethynyl isocyanate, propynyl isocyanate;
Monomethylene diisocyanate, dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, 1,3-bis ( Isocyanatomethyl) cyclohexane, dicyclohexylmethane-4,4′-diisocyanate, bicyclo [2.2.1] heptane-2,
5-diylbis (methylisocyanate), bicyclo [2.2.1] heptane-2,6-
Hydrocarbon diisocyanate compounds such as diylbis (methyl isocyanate), isophorone diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate;
Isocyanate compounds such as diisocyanatosulfone, (ortho-, meta-, para-) toluenesulfonyl isocyanate, benzenesulfonyl isocyanate, fluorosulfonyl isocyanate, phenoxysulfonyl isocyanate, pentafluorophenoxysulfonyl isocyanate, methoxysulfonyl isocyanate;
Is preferable from the viewpoint of improving cycle characteristics and storage characteristics.

More preferably, allyl isocyanate, hexamethylene diisocyanate, 1,3
-Bis (isocyanatomethyl) cyclohexane, diisocyanatosulfone, (ortho-,
Meta-, para-) toluenesulfonyl isocyanate is preferred, particularly preferably hexamethylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, (
Ortho-, meta-, para-) toluenesulfonyl isocyanate is preferred, and hexamethylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane is most preferred.

Moreover, as an isocyanate compound, the isocyanate compound which has a branched chain is preferable.
The isocyanate compound used in the present invention may be a trimer compound derived from a compound having at least two isocyanate groups in the molecule, or an aliphatic polyisocyanate obtained by adding a polyhydric alcohol thereto. For example, the following general formulas (3-1) to (3)
-4) biuret, isocyanurate, adduct, and bifunctional type modified polyisocyanate represented by the basic structure can be exemplified (the following general formulas (1-2-1) to (1-2)
In 4), R and R ′ are each independently any hydrocarbon group).

The compound having at least two isocyanate groups in the molecule used in the present invention also includes so-called blocked isocyanate which is blocked with a blocking agent to enhance storage stability. Examples of the blocking agent include alcohols, phenols, organic amines, oximes, and lactams. Specific examples include n-butanol, phenol, tributylamine, diethylethanolamine, methyl ethyl ketoxime, and ε-caprolactam. Etc.

In order to promote a reaction based on a compound having at least two isocyanate groups in the molecule and obtain a higher effect, a metal catalyst such as dibutyltin dilaurate or the like, 1,8-diazabicyclo [5.4.0] undecene- It is also preferable to use an amine catalyst such as 7 in combination.
Furthermore, the compound which has an isocyanate group may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

There is no restriction | limiting in the compounding quantity of the compound which has an isocyanate group with respect to the whole nonaqueous electrolyte solution of this invention, Although it is arbitrary unless the effect of this invention is impaired remarkably, Usually, it is 0.8 with respect to the nonaqueous electrolyte solution of this invention. 001 mass% or more, preferably 0.01 mass% or more, more preferably 0.1
% By mass or more, usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 2% by mass or less, particularly preferably 1% by mass or less, most preferably 0.5% by mass. It is contained at a concentration of not more than%.

When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, and high temperature storage characteristics are further improved.
1-1-4. Difluorophosphate Counter cation of difluorophosphate is not particularly limited, but lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, barium, and NR11R12R13R14 (wherein R11 to R14 are each independently , Represents a hydrogen atom or an organic group having 1 to 12 carbon atoms).

The organic group having 1 to 12 carbon atoms represented by R11 to R14 of ammonium is not particularly limited. Examples thereof include a good cycloalkyl group, an aryl group which may be substituted with a halogen atom or an alkyl group, and a nitrogen atom-containing heterocyclic group which may have a substituent. Among them, as R11 to R14, each independently, a hydrogen atom, an alkyl group,
A cycloalkyl group or a nitrogen atom-containing heterocyclic group is preferred.

Specific examples of difluorophosphate include
Examples include lithium difluorophosphate, sodium difluorophosphate, and potassium difluorophosphate, and lithium difluorophosphate is preferred.
A difluorophosphate may be used individually by 1 type, or may use 2 or more types together by arbitrary combinations and a ratio. Moreover, the compounding quantity of a difluorophosphate is not restrict | limited in particular, As long as the effect of this invention is not impaired remarkably, it is arbitrary.

The blending amount of difluorophosphate is usually 0.001% by mass in 100% by mass of the non-aqueous electrolyte.
Or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 1%
It is contained at a concentration of 0% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, further preferably 2% by mass or less, and most preferably 1% by mass or less.
Within this range, the non-aqueous electrolyte battery tends to exhibit a sufficient cycle characteristics improvement effect, and the high temperature storage characteristics are reduced, the amount of gas generated is increased, and the discharge capacity maintenance ratio is reduced. Easy to avoid.

1-1-5. Fluorosulfonate The counter cation of the fluorosulfonate is not particularly limited, but lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, barium, and NR11R12R13R14 (wherein R11 to R14 are each independently , Represents a hydrogen atom or an organic group having 1 to 12 carbon atoms).

The organic group having 1 to 12 carbon atoms represented by R11 to R14 of ammonium is not particularly limited. Examples thereof include a good cycloalkyl group, an aryl group which may be substituted with a halogen atom or an alkyl group, and a nitrogen atom-containing heterocyclic group which may have a substituent. Among them, as R11 to R14, each independently, a hydrogen atom, an alkyl group,
A cycloalkyl group or a nitrogen atom-containing heterocyclic group is preferred.

As specific examples of fluorosulfonate,
Examples thereof include lithium fluorosulfonate, sodium fluorosulfonate, potassium fluorosulfonate, rubidium fluorosulfonate, cesium fluorosulfonate, and the like, and lithium fluorosulfonate is preferable.
A fluorosulfonate may be used individually by 1 type, or may use 2 or more types together by arbitrary combinations and a ratio. Moreover, the compounding quantity of a fluorosulfonate is not restrict | limited in particular, As long as the effect of this invention is not impaired remarkably, it is arbitrary.

The blending amount of the monofluorosulfonate is usually 0.001 in 100% by mass of the non-aqueous electrolyte.
% By mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more,
The concentration is usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, further preferably 2% by mass or less, and most preferably 1% by mass or less.
Within this range, the non-aqueous electrolyte battery tends to exhibit a sufficient cycle characteristics improvement effect, and the high temperature storage characteristics are reduced, the amount of gas generated is increased, and the discharge capacity maintenance ratio is reduced. Easy to avoid.
1-1-7. Lithium bis (fluorosulfonyl) imide The structural formula is represented by the following formula (c).

The blending amount of lithium bis (fluorosulfonyl) imide is usually 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, in 100% by mass of the non-aqueous electrolyte. Usually, it is contained at a concentration of 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, further preferably 2% by mass or less, and most preferably 1% by mass or less.
Within this range, the non-aqueous electrolyte battery tends to exhibit a sufficient cycle characteristics improvement effect, and the high temperature storage characteristics are reduced, the amount of gas generated is increased, and the discharge capacity maintenance ratio is reduced. Easy to avoid.
1-1-8. Compound having structure represented by general formula (B)

In formula (B), R ₁ , R ₂ and R ₃ each independently represent an alkyl group, alkenyl group or alkynyl group having 1 to 12 carbon atoms which may be substituted with a halogen atom, and n is 0
Represents an integer of ~ 6.
Examples of the compound represented by the general formula (B) include the following compounds.

<Compound with n = 0 in the general formula (B)>
Trimethyl phosphonoformate, methyl diethylphosphonoformate, methyl dipropylphosphonoformate, methyl dibutylphosphonoformate, triethyl phosphonoformate, ethyl dimethylphosphonoformate, ethyl dipropylphosphonoformate, ethyl Dibutyl phosphonoformate, tripropyl phosphonoformate, propyl dimethylphosphonoformate, propyl diethylphosphonoformate, propyl dibutylphosphonoformate, tributyl phosphonoformate, butyl dimethylphosphonoformate, butyl diethylphospho Noformate, butyl dipropylphosphonoformate, methyl bis (2,2,2-trifluoroethyl) phosphonoformate, ethyl bis (2 2,2-trifluoroethyl) phosphonoacetate formate, propyl bis (2,2,2-trifluoroethyl) phosphonoacetate formate, butyl bis (2,2,2-trifluoroethyl) phosphonoacetate formate and the like.

<Compound with n = 1 in the general formula (B)>
Trimethyl phosphonoacetate, methyl diethyl phosphonoacetate, methyl dipropyl phosphonoacetate, methyl dibutyl phosphonoacetate, triethyl phosphonoacetate, ethyl dimethylphosphonoacetate, ethyl dipropylphosphonoacetate, ethyl dibutylphosphonoacetate, tripropyl Phosphonoacetate,
Propyl dimethylphosphonoacetate, propyl diethylphosphonoacetate, propyl dibutylphosphonoacetate, tributylphosphonoacetate, butyldimethylphosphonoacetate, butyldiethylphosphonoacetate, butyldipropylphosphonoacetate, methylbis (2,2,2 -Trifluoroethyl) phosphonoacetate, ethyl bis (2,2,2-trifluoroethyl) phosphonoacetate, propyl bis (2,2,2-trifluoroethyl) phosphonoacetate, butyl bis (2,2, 2
-Trifluoroethyl) phosphonoacetate, allyl dimethylphosphonoacetate, allyl diethylphosphonoacetate, 2-propynyl dimethylphosphonoacetate, 2
-Propynyl diethylphosphonoacetate and the like.

<Compound with n = 2 in the general formula (B)>
Trimethyl 3-phosphonopropionate, methyl 3- (diethylphosphono) propionate, methyl 3- (dipropylphosphono) propionate, methyl 3- (dibutylphosphono) propionate, triethyl 3-phosphonopropionate, ethyl 3-
(Dimethylphosphono) propionate, ethyl 3- (dipropylphosphono) propionate, ethyl 3- (dibutylphosphono) propionate, tripropyl 3-phosphonopropionate, propyl 3- (dimethylphosphono) propionate, propyl 3 −
(Diethylphosphono) propionate, propyl 3- (dibutylphosphono) propionate, tributyl 3-phosphonopropionate, butyl 3- (dimethylphosphono) propionate, butyl 3- (diethylphosphono) propionate, butyl 3- ( Dipropylphosphono) propionate, methyl 3- (bis (2,2,2-trifluoroethyl) phosphono) propionate, ethyl 3- (bis (2,2,2-trifluoroethyl) phosphono) propionate, propyl 3- (Bis (2,2,2-trifluoroethyl) phosphono) propionate, butyl 3- (bis (2,2,2-trifluoroethyl)
Phosphono) propionate and the like.

<Compound with n = 3 in the general formula (B)>
Trimethyl 4-phosphonobutyrate, methyl 4- (diethylphosphono) butyrate, methyl 4- (dipropylphosphono) butyrate, methyl 4- (dibutylphosphono)
Butyrate, triethyl 4-phosphonobutyrate, ethyl 4- (dimethylphosphono)
Butyrate, ethyl 4- (dipropylphosphono) butyrate, ethyl 4- (dibutylphosphono) butyrate, tripropyl 4-phosphonobutyrate, propyl 4- (dimethylphosphono) butyrate, propyl 4- (diethylphosphono) Butyrate, propyl 4- (dibutylphosphono) butyrate, tributyl 4-phosphonobutyrate, butyl 4- (dimethylphosphono) butyrate, butyl 4- (diethylphosphono) butyrate, butyl 4- (dipropylphosphono) butyrate etc.

Among these, from the viewpoint of improving battery characteristics, compounds of n = 0, 1, 2 are preferable, n = 0,
1 is particularly preferred, and n = 1 is most preferred.
Among the compounds with n = 1, compounds in which R1 to R3 are saturated hydrocarbon groups are preferable.
1-1-9. Cyclic carbonate having a fluorine atom Examples of the cyclic carbonate compound having a fluorine atom include a fluorinated product of a cyclic carbonate having an alkylene group having 2 to 6 carbon atoms, and a derivative thereof, for example, a fluorinated product of ethylene carbonate, and a derivative thereof. Is mentioned. Examples of the derivatives of fluorinated ethylene carbonate include fluorinated ethylene carbonate substituted with an alkyl group (for example, an alkyl group having 1 to 4 carbon atoms). Of these, ethylene carbonate having 1 to 8 fluorine atoms and derivatives thereof are preferred.

In particular,
Monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, 4,
5-difluoroethylene carbonate, 4-fluoro-4-methylethylene carbonate, 4,5-difluoro-4-methylethylene carbonate, 4-fluoro-5-methylethylene carbonate, 4,4-difluoro-5-methylethylene carbonate, 4- (fluoromethyl) -ethylene carbonate, 4- (difluoromethyl) -ethylene carbonate, 4- (trifluoromethyl) -ethylene carbonate, 4- (fluoromethyl)-
4-fluoroethylene carbonate, 4- (fluoromethyl) -5-fluoroethylene carbonate, 4-fluoro-4,5-dimethylethylene carbonate, 4,5-difluoro-4,5-dimethylethylene carbonate, 4,4-difluoro Examples include -5,5-dimethylethylene carbonate.

Among them, at least one selected from the group consisting of monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, and 4,5-difluoroethylene carbonate provides high ion conductivity and suitably forms an interface protective film. And more preferable.
One cyclic carbonate compound having a fluorine atom may be used alone, or two or more cyclic carbonate compounds may be used in any combination and ratio.

One cyclic carbonate compound having a fluorine atom may be used alone, or two or more cyclic carbonate compounds may be used in any combination and ratio. There is no limitation on the blending amount of the halogenated cyclic carbonate with respect to the whole non-aqueous electrolyte of the present invention, and it is optional as long as the effect of the present invention is not significantly impaired. % By weight or more, preferably 0.
05 wt% or more, more preferably 0.1 wt% or more, and usually 50 wt% or less, preferably 30 wt% or less, more preferably 20 wt% or less, particularly preferably 10 wt% or less,
Most preferably, it is contained at a concentration of 5% by weight or less.

1-2. Electrolyte <Lithium salt>
As the electrolyte, a lithium salt is usually used. The lithium salt is not particularly limited as long as it is known to be used in this application, and any lithium salt can be used.
Specific examples include the following.

For _{example, LiPF 6, LiBF 4, LiClO} 4, LiAlF 4, LiSbF 6, Li
Inorganic lithium salts such as TaF ₆ and LiWF ₇ ;
Lithium tungstates such as LiWOF ₅ ;
HCO ₂ Li, CH ₃ CO ₂ Li, CH ₂ FCO ₂ Li, CHF ₂ CO ₂ Li, CF ₃
CO ₂ Li, CF ₃ CH ₂ CO ₂ Li, CF ₃ CF ₂ CO ₂ Li, CF ₃ CF ₂ CF ₂ C
Carboxylic acid lithium salts such as O ₂ Li, CF ₃ CF ₂ CF ₂ CF ₂ CO ₂ Li;
FSO ₃ Li, CH ₃ SO ₃ Li, CH ₂ FSO ₃ Li, CHF ₂ SO ₃ Li, CF ₃
SO ₃ Li, CF ₃ CF ₂ SO ₃ Li, CF ₃ CF ₂ CF ₂ SO ₃ Li, CF ₃ CF ₂ C
Sulfonic acid lithium salts such as F ₂ CF ₂ SO ₃ Li;
LiN (FCO) ₂ , LiN (FCO) (FSO ₂ ), LiN (FSO ₂ ) ₂ , LiN
(FSO ₂ ) (CF ₃ SO ₂ ), LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ )
₂ , lithium cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,3
- perfluoropropane _{disulfonylimide, LiN (CF 3 SO 2)} (C 4 F 9 SO 2
) Lithium imide salts;
Lithium metide salts such as LiC (FSO ₂ ) ₃ , LiC (CF ₃ SO ₂ ) ₃ , LiC (C ₂ F ₅ SO ₂ ) ₃ ;

Lithium oxalatoborate salts such as lithium difluorooxalatoborate and lithium bis (oxalato) borate;
Lithium oxalate phosphate salts such as lithium tetrafluorooxalatophosphate, lithium difluorobis (oxalato) phosphate, lithium tris (oxalato) phosphate;
In addition, LiPF ₄ (CF ₃ ) ₂ , LiPF ₄ (C ₂ F ₅ ) ₂ , LiPF ₄ (CF ₃ S
O ₂ ) ₂ , LiPF ₄ (C ₂ F ₅ SO ₂ ) ₂ , LiBF ₃ CF ₃ , LiBF ₃ C ₂ F ₅ ,
LiBF ₃ C ₃ F ₇ , LiBF ₂ (CF ₃ ) _2, LiBF ₂ (C ₂ F ₅ ) ₂ , LiBF ₂
Fluorine-containing organic lithium salts such as (CF ₃ SO ₂ ) ₂ and LiBF ₂ (C ₂ F ₅ SO ₂ ) 2;
Etc.

Among them, LiPF ₆ , LiBF ₄ , LiSbF ₆ , LiTaF ₆ , FSO ₃ Li, CF
₃ SO ₃ Li, LiN (FSO ₂ ) ₂ , LiN (FSO ₂ ) (CF ₃ SO ₂ ), LiN (
_{CF 3 SO 2) 2, LiN} (C 2 F 5 SO 2) 2, lithium cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,3-perfluoropropanedisulfonylimide, LiC _{(FSO 2) 3} , LiC (CF ₃ SO ₂ ) ₃ , LiC (C ₂ F ₅ SO ₂ ) ₃ ,
Lithium bisoxalatoborate, lithium difluorooxalatoborate, lithium tetrafluorooxalatophosphate, lithium difluorobisoxalatophosphate, LiBF ₃ CF ₃ , LiBF ₃ C ₂ F ₅ , LiPF ₃ (CF ₃ ) ₃ , LiPF ₃ ( C
₂ F ₅ ) _{3 and the} like are particularly preferable from the viewpoint of improving output characteristics, high-rate charge / discharge characteristics, high-temperature storage characteristics, cycle characteristics, and the like.

These lithium salts may be used alone or in combination of two or more. A preferable example in the case of using 2 or more types together is LiPF ₆ and LiBF ₄ , LiPF ₆ and LiN (FSO ₂ ) _2.
In addition, LiPF ₆ and FSO ₃ Li are used in combination, and have an effect of improving load characteristics and cycle characteristics.
In this case, the concentration of LiBF ₄ or FSO ₃ Li with respect to 100% by mass of the entire non-aqueous electrolyte solution is not limited as long as it does not significantly impair the effects of the present invention. On the other hand, it is usually 0.01% by mass or more, preferably 0.1% by mass or more, and usually 30% by mass or less, preferably 20% by mass or less.

Another example is the combined use of an inorganic lithium salt and an organic lithium salt, and the combined use of both has the effect of suppressing deterioration due to high-temperature storage. As an organic lithium salt, CF ₃ SO ₃
Li, LiN (FSO ₂ ) ₂ , LiN (FSO ₂ ) (CF ₃ SO ₂ ), LiN (CF ₃ S
O ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , lithium cyclic 1,2-perfluoroethanedisulfonylimide, lithium cyclic 1,3-perfluoropropane disulfonylimide, Li
C (FSO ₂ ) ₃ , LiC (CF ₃ SO ₂ ) ₃ , LiC (C ₂ F ₅ SO ₂ ) ₃ , lithium bisoxalatoborate, lithium difluorooxalatoborate, lithium tetrafluorooxalatophosphate, lithium difluorobisoxa Latophosphate, Li
BF ₃ CF ₃ , LiBF ₃ C2F ₅ , LiPF ₃ (CF ₃ ) ₃ , LiPF ₃ (C ₂ F ₅ )
_It is preferably ₃ etc. In this case, the ratio of the organic lithium salt to 100% by mass of the entire non-aqueous electrolyte is preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, and preferably 30% by mass or less. Especially preferably, it is 20 mass% or less.

The concentration of these lithium salts in the non-aqueous electrolyte solution is not particularly limited as long as the effects of the present invention are not impaired, but the electric conductivity of the electrolyte solution is in a good range, and good battery performance is ensured. Therefore, the total molar concentration of lithium in the non-aqueous electrolyte is preferably 0.3 mol /
L or more, more preferably 0.4 mol / L or more, still more preferably 0.5 mol / L or more, preferably 3 mol / L or less, more preferably 2.5 mol / L or less, still more preferably 2.0 mol. / L or less.
When the total molar concentration of lithium is within the above range, the electric conductivity of the electrolytic solution becomes sufficient, and the decrease in electric conductivity due to the increase in viscosity and the decrease in battery performance resulting therefrom are prevented.

1-3. Nonaqueous solvent There is no restriction | limiting in particular about the nonaqueous solvent in this invention, It is possible to use a well-known organic solvent. Examples thereof include cyclic carbonates having no fluorine atom, chain carbonates, cyclic and chain carboxylic acid esters, ether compounds, sulfone compounds, and the like.

<Cyclic carbonate without fluorine atoms>
Examples of the cyclic carbonate having no fluorine atom include cyclic carbonates having an alkylene group having 2 to 4 carbon atoms.
Specific examples of the cyclic carbonate having 2 to 4 carbon atoms and having no fluorine atom include ethylene carbonate, propylene carbonate, and butylene carbonate. Among these, ethylene carbonate and propylene carbonate are particularly preferable from the viewpoint of improving battery characteristics resulting from an improvement in the degree of lithium ion dissociation.

The cyclic carbonate which does not have a fluorine atom may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.
The blending amount of the cyclic carbonate not having a fluorine atom is not particularly limited, and is arbitrary as long as the effects of the present invention are not significantly impaired.
In 0 volume%, it is 5 volume% or more, More preferably, it is 10 volume% or more. By setting this range, the decrease in electrical conductivity due to the decrease in the dielectric constant of the non-aqueous electrolyte is avoided, and the high current discharge characteristics, stability against the negative electrode, and cycle characteristics of the non-aqueous electrolyte battery are in a good range. And it will be easier.
Moreover, it is 95 volume% or less, More preferably, it is 90 volume% or less, More preferably, it is 85 volume% or less. By setting it as this range, the viscosity of the non-aqueous electrolyte solution is set to an appropriate range, the decrease in ionic conductivity is suppressed, and the load characteristics of the non-aqueous electrolyte battery are easily set in a favorable range.

<Chain carbonate>
As the chain carbonate, a chain carbonate having 3 to 7 carbon atoms is preferable.
More preferred is 7 dialkyl carbonate.
Specific examples of the chain carbonate include dimethyl carbonate, diethyl carbonate,
Di-n-propyl carbonate, diisopropyl carbonate, n-propyl isopropyl carbonate, ethyl methyl carbonate, methyl-n-propyl carbonate, n-
Examples include butyl methyl carbonate, isobutyl methyl carbonate, t-butyl methyl carbonate, ethyl-n-propyl carbonate, n-butyl ethyl carbonate, isobutyl ethyl carbonate, t-butyl ethyl carbonate and the like.

Among them, dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propyl isopropyl carbonate, ethyl methyl carbonate, and methyl n-propyl carbonate are preferable, and dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate are particularly preferable. is there.
Also, chain carbonates having fluorine atoms (hereinafter referred to as “fluorinated chain carbonate”)
Can also be suitably used.

The number of fluorine atoms contained in the fluorinated chain carbonate is not particularly limited as long as it is 1 or more, but is usually 6 or less, preferably 4 or less. When the fluorinated chain carbonate has a plurality of fluorine atoms, they may be bonded to the same carbon or may be bonded to different carbons.
As the fluorinated chain carbonate, fluorinated dimethyl carbonate and its derivatives,
Examples thereof include fluorinated ethyl methyl carbonate and derivatives thereof, and fluorinated diethyl carbonate and derivatives thereof.

Fluorinated dimethyl carbonate and derivatives thereof include fluoromethyl methyl carbonate, difluoromethyl methyl carbonate, trifluoromethyl methyl carbonate, bis (fluoromethyl) carbonate, bis (difluoro) methyl carbonate, bis (trifluoromethyl) carbonate, and the like. It is done.
Fluorinated ethyl methyl carbonate and derivatives thereof include 2-fluoroethyl methyl carbonate, ethyl fluoromethyl carbonate, 2,2-difluoroethyl methyl carbonate, 2-fluoroethyl fluoromethyl carbonate, ethyl difluoromethyl carbonate, 2,2,2 -Trifluoroethyl methyl carbonate, 2,2-difluoroethyl fluoromethyl carbonate, 2-fluoroethyl difluoromethyl carbonate, ethyl trifluoromethyl carbonate, etc. are mentioned.

Fluorinated diethyl carbonate and its derivatives include ethyl- (2-fluoroethyl) carbonate, ethyl- (2,2-difluoroethyl) carbonate, bis (2-fluoroethyl) carbonate, ethyl- (2,2,2- Trifluoroethyl) carbonate, 2,2-difluoroethyl-2′-fluoroethyl carbonate, bis (2,2-difluoroethyl) carbonate, 2,2,2-trifluoroethyl-2′-fluoroethyl carbonate, 2, Examples include 2,2-trifluoroethyl-2 ′, 2′-difluoroethyl carbonate, bis (2,2,2-trifluoroethyl) carbonate, and the like.

A chain carbonate may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
The amount of the chain carbonate is preferably 5% by volume or more, more preferably 10% by volume or more, and further preferably 15% by volume or more in 100% by volume of the non-aqueous solvent. By setting the lower limit in this way, the viscosity of the non-aqueous electrolyte solution is set in an appropriate range, the decrease in ionic conductivity is suppressed, and the large current discharge characteristics of the non-aqueous electrolyte battery are easily set in a favorable range. Also,
The chain carbonate is preferably 90% by volume or less, more preferably 85% by volume or less, and particularly preferably 80% by volume or less in 100% by volume of the non-aqueous solvent. By setting the upper limit in this way, it is easy to avoid a decrease in electrical conductivity resulting from a decrease in dielectric constant of the nonaqueous electrolyte solution, and to make the large current discharge characteristics of the nonaqueous electrolyte solution battery in a favorable range.

<Cyclic carboxylic acid ester>
The cyclic carboxylic acid ester is preferably one having 3 to 12 carbon atoms.
Specifically, gamma butyrolactone, gamma valerolactone, gamma caprolactone,
Epsilon caprolactone and the like. Among these, gamma butyrolactone is particularly preferable from the viewpoint of improving battery characteristics resulting from an improvement in the degree of lithium ion dissociation.

A cyclic carboxylic acid ester may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
The amount of the cyclic carboxylic acid ester is usually 5% by volume or more, more preferably 10% by volume or more, in 100% by volume of the non-aqueous solvent. If it is this range, it will become easy to improve the electrical conductivity of a non-aqueous electrolyte solution, and to improve the large current discharge characteristic of a non-aqueous electrolyte battery. Moreover, the compounding quantity of cyclic carboxylic acid ester becomes like this. Preferably it is 50 volume% or less, More preferably, it is 40 volume% or less. By setting the upper limit in this way, the viscosity of the non-aqueous electrolyte solution is set to an appropriate range, a decrease in electrical conductivity is avoided, an increase in negative electrode resistance is suppressed, and a large current discharge of the non-aqueous electrolyte secondary battery is performed. It becomes easy to make a characteristic into a favorable range.

<Ether compound>
As an ether compound, a part of hydrogen atoms may be substituted with fluorine atoms having 3 to 3 carbon atoms.
10 chain ethers and C3-C6 cyclic ethers are preferred.
As the chain ether having 3 to 10 carbon atoms,
Diethyl ether, di (2-fluoroethyl) ether, di (2,2-difluoroethyl) ether, di (2,2,2-trifluoroethyl) ether, ethyl (2-fluoroethyl) ether, ethyl (2, 2,2-trifluoroethyl) ether, ethyl (1,
1,2,2-tetrafluoroethyl) ether, (2-fluoroethyl) (2,2,2-
Trifluoroethyl) ether, (2-fluoroethyl) (1,1,2,2-tetrafluoroethyl) ether, (2,2,2-trifluoroethyl) (1,1,2,2-tetrafluoroethyl) ) Ether, ethyl-n-propyl ether, ethyl (3-fluoro-n)
-Propyl) ether, ethyl (3,3,3-trifluoro-n-propyl) ether,
Ethyl (2,2,3,3-tetrafluoro-n-propyl) ether, ethyl (2,2,
3,3,3-pentafluoro-n-propyl) ether, 2-fluoroethyl-n-propyl ether, (2-fluoroethyl) (3-fluoro-n-propyl) ether, (2
-Fluoroethyl) (3,3,3-trifluoro-n-propyl) ether, (2-fluoroethyl) (2,2,3,3-tetrafluoro-n-propyl) ether, (2-fluoroethyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, 2,2
, 2-trifluoroethyl-n-propyl ether, (2,2,2-trifluoroethyl) (3-fluoro-n-propyl) ether, (2,2,2-trifluoroethyl) (3
, 3,3-trifluoro-n-propyl) ether, (2,2,2-trifluoroethyl) (2,2,3,3-tetrafluoro-n-propyl) ether, (2,2,2- Trifluoroethyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, 1,
1,2,2-tetrafluoroethyl-n-propyl ether, (1,1,2,2-tetrafluoroethyl) (3-fluoro-n-propyl) ether, (1,1,2,2-tetrafluoro Ethyl) (3,3,3-trifluoro-n-propyl) ether, (1,1,2
, 2-tetrafluoroethyl) (2,2,3,3-tetrafluoro-n-propyl) ether, (1,1,2,2-tetrafluoroethyl) (2,2,3,3,3-penta Fluoro-n-propyl) ether, di-n-propylether, (n-propyl) (3-fluoro-n-propyl) ether, (n-propyl) (3,3,3-trifluoro-n-propyl) Ether, (n-propyl) (2,2,3,3-tetrafluoro-n-propyl) ether, (n-propyl) (2,2,3,3,3-pentafluoro-n-propyl)
Ether, di (3-fluoro-n-propyl) ether, (3-fluoro-n-propyl) (3,3,3-trifluoro-n-propyl) ether, (3-fluoro-n-propyl) (2 , 2,3,3-tetrafluoro-n-propyl) ether, (3-fluoro-n
-Propyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, di (3
, 3,3-trifluoro-n-propyl) ether, (3,3,3-trifluoro-n-
Propyl) (2,2,3,3-tetrafluoro-n-propyl) ether, (3,3,3
-Trifluoro-n-propyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, di (2,2,3,3-tetrafluoro-n-propyl) ether, (2, 2
, 3,3-tetrafluoro-n-propyl) (2,2,3,3,3-pentafluoro-n
-Propyl) ether, di (2,2,3,3,3-pentafluoro-n-propyl) ether, di-n-butylether, dimethoxymethane, methoxyethoxymethane, methoxy (2-fluoroethoxy) methane, methoxy ( 2,2,2-trifluoroethoxy) methanemethoxy (1,1,2,2-tetrafluoroethoxy) methane, diethoxymethane, ethoxy (2-fluoroethoxy) methane, ethoxy (2,2,2-trifluoro) Ethoxy) methane, ethoxy (1,1,2,2-tetrafluoroethoxy) methane, di (2-fluoroethoxy) methane, (2-fluoroethoxy) (2,2,2-trifluoroethoxy) methane, (2 -Fluoroethoxy) (1,1,2,2-tetrafluoroethoxy) methane di (2,2,2-trifluoro) Roethoxy) methane, (2,2,2-trifluoroethoxy) (1,1,2,2-tetrafluoroethoxy) methane, di (1,1,2,2-tetrafluoroethoxy) methane, dimethoxyethane, methoxy Ethoxyethane, methoxy (2
-Fluoroethoxy) ethane, methoxy (2,2,2-trifluoroethoxy) ethane,
Methoxy (1,1,2,2-tetrafluoroethoxy) ethane, diethoxyethane, ethoxy (2-fluoroethoxy) ethane, ethoxy (2,2,2-trifluoroethoxy)
Ethane, ethoxy (1,1,2,2-tetrafluoroethoxy) ethane, di (2-fluoroethoxy) ethane, (2-fluoroethoxy) (2,2,2-trifluoroethoxy)
Ethane, (2-fluoroethoxy) (1,1,2,2-tetrafluoroethoxy) ethane, di (2,2,2-trifluoroethoxy) ethane, (2,2,2-trifluoroethoxy) (1 , 1,2,2-tetrafluoroethoxy) ethane, di (1,1,2,2-tetrafluoroethoxy) ethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, diethylene glycol dimethyl ether, etc. Can be mentioned.

Examples of the cyclic ether having 3 to 6 carbon atoms include tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, 1,3-dioxane, 2-methyl-1,3-dioxane, 4-methyl-1,3-dioxane, 1 , 4-dioxane and the like, and fluorinated compounds thereof.
Among them, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether have high solvating ability to lithium ions and improve ion dissociation. Of these, dimethoxymethane, diethoxymethane, and ethoxymethoxymethane are preferable because they have low viscosity and give high ionic conductivity.

An ether type compound may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
The compounding amount of the ether compound is usually in 100% by volume of the non-aqueous solvent, preferably 5% by volume or more, more preferably 10% by volume or more, further preferably 15% by volume or more, and preferably 70% by volume or less. More preferably, it is 60 volume% or less, More preferably, it is 50 volume% or less.

If it is this range, it is easy to ensure the improvement effect of the lithium ion dissociation degree of chain ether, and the improvement of the ionic conductivity derived from a viscosity fall. It is easy to avoid a situation where the capacity is reduced due to co-insertion.
<Sulfone compound>
As the sulfone compound, a cyclic sulfone having 3 to 6 carbon atoms and a chain sulfone having 2 to 6 carbon atoms are preferable. The number of sulfonyl groups in one molecule is preferably 1 or 2.

As cyclic sulfone having 3 to 6 carbon atoms,
Monosulfone compounds trimethylene sulfones, tetramethylene sulfones, hexamethylene sulfones;
Examples include disulfone compounds such as trimethylene disulfones, tetramethylene disulfones, and hexamethylene disulfones.

Among these, from the viewpoint of dielectric constant and viscosity, tetramethylene sulfones, tetramethylene disulfones, hexamethylene sulfones, and hexamethylene disulfones are more preferable, and tetramethylene sulfones (sulfolanes) are particularly preferable.
As the sulfolanes, sulfolane and / or sulfolane derivatives (hereinafter sometimes referred to as “sulfolanes” including sulfolane) are preferable. The sulfolane derivative is preferably one in which one or more hydrogen atoms bonded to the carbon atoms constituting the sulfolane ring are substituted with a fluorine atom or an alkyl group.

Among them, 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, 3
-Fluorosulfolane, 2,2-difluorosulfolane, 2,3-difluorosulfolane, 2,4-difluorosulfolane, 2,5-difluorosulfolane, 3,4-difluorosulfolane, 2-fluoro-3-methylsulfolane, 2- Fluoro-2-methylsulfolane, 3-fluoro-3-methylsulfolane, 3-fluoro-2-methylsulfolane, 4-
Fluoro-3-methyl sulfolane, 4-fluoro-2-methyl sulfolane, 5-fluoro-3-methyl sulfolane, 5-fluoro-2-methyl sulfolane, 2-fluoromethyl sulfolane, 3-fluoromethyl sulfolane, 2-difluoromethyl Sulfolane, 3-difluoromethylsulfolane, 2-trifluoromethylsulfolane, 3-trifluoromethylsulfolane, 2-fluoro-3- (trifluoromethyl) sulfolane, 3-fluoro-3
-(Trifluoromethyl) sulfolane, 4-fluoro-3- (trifluoromethyl) sulfolane, 5-fluoro-3- (trifluoromethyl) sulfolane and the like are preferable in terms of high ionic conductivity and high input / output characteristics. .

In addition, as the chain sulfone having 2 to 6 carbon atoms,
Dimethylsulfone, ethylmethylsulfone, diethylsulfone, n-propylmethylsulfone, n-propylethylsulfone, di-n-propylsulfone, isopropylmethylsulfone, isopropylethylsulfone, diisopropylsulfone, n-butylmethylsulfone, n-butylethyl Sulfone, t-butylmethylsulfone, t-butylethylsulfone, monofluoromethylmethylsulfone, difluoromethylmethylsulfone, trifluoromethylmethylsulfone, monofluoroethylmethylsulfone, difluoroethylmethylsulfone, trifluoroethylmethylsulfone, pentafluoro Ethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, ethyl trifluoromethyl sulfone, perf Oro ethyl methyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoroethyl sulfone, di (trifluoroethyl) sulfone,
Perfluorodiethylsulfone, fluoromethyl-n-propylsulfone, difluoromethyl-n-propylsulfone, trifluoromethyl-n-propylsulfone, fluoromethylisopropylsulfone, difluoromethylisopropylsulfone, trifluoromethylisopropylsulfone, trifluoroethyl- n-propylsulfone, trifluoroethylisopropylsulfone, pentafluoroethyl-n-propylsulfone, pentafluoroethylisopropylsulfone, trifluoroethyl-n-butylsulfone, trifluoroethyl-t-butylsulfone, pentafluoroethyl-n- Examples include butyl sulfone and pentafluoroethyl-t-butyl sulfone.

Among them, dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl methyl sulfone, isopropyl methyl sulfone, n-butyl methyl sulfone, t-butyl methyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone, trifluoromethyl methyl sulfone , Monofluoroethyl methyl sulfone, difluoroethyl methyl sulfone, trifluoroethyl methyl sulfone, pentafluoroethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, ethyl trifluoromethyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoro Ethyl sulfone, trifluoromethyl-n-propyl sulfone, trifluoromethyl isopropyl sulfone, tri Ruoroechiru -n- butyl sulfone, trifluoroethyl -t- butyl sulfone, trifluoromethyl -n- butyl sulfone, trifluoromethyl -t- butyl sulfone is high ion conductivity, preferable because the input-output characteristic is high.

A sulfone compound may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
The compounding amount of the sulfone compound is usually 0.3% by volume or more, more preferably 1% by volume or more, still more preferably 5% by volume or more in 100% by volume of the non-aqueous solvent, and preferably 40%. % By volume or less, more preferably 35% by volume or less, still more preferably 30% by volume.
It is as follows.

Within this range, durability improvement effects such as cycle characteristics and storage characteristics can be easily obtained, and the viscosity of the non-aqueous electrolyte can be set to an appropriate range to avoid a decrease in electrical conductivity. When charging / discharging an aqueous electrolyte battery at a high current density, it is easy to avoid a situation in which the charge / discharge capacity retention rate decreases.

<When using a cyclic carbonate having a fluorine atom as a non-aqueous solvent>
In the present invention, when a cyclic carbonate having a fluorine atom is used as a non-aqueous solvent, one of the non-aqueous solvents exemplified above is combined with a cyclic carbonate having a fluorine atom as a non-aqueous solvent other than the cyclic carbonate having a fluorine atom. Two or more kinds may be used in combination with a cyclic carbonate having a fluorine atom.

For example, one preferred combination of non-aqueous solvents is a combination mainly composed of a cyclic carbonate having a fluorine atom and a chain carbonate. Among them, the total of the cyclic carbonate having a fluorine atom and the chain carbonate in the non-aqueous solvent is preferably 60% by volume.
Or more, more preferably 80% by volume or more, still more preferably 90% by volume or more, and the ratio of the cyclic carbonate having a fluorine atom to the total of the cyclic carbonate having a fluorine atom and the chain carbonate is 3% by volume or more, preferably Is 5% by volume or more, more preferably 1
0 volume% or more, more preferably 15 volume% or more, and usually 60 volume% or less, preferably 50 volume% or less, more preferably 40 volume% or less, still more preferably 35 volume% or less, particularly preferably 30 volume. % Or less, most preferably 20% by volume or less.

When a combination of these non-aqueous solvents is used, the balance between the cycle characteristics and high-temperature storage characteristics (particularly, the remaining capacity and high-load discharge capacity after high-temperature storage) of a battery produced using the non-aqueous solvent may be improved.
For example, as a specific example of a preferable combination of a cyclic carbonate having a fluorine atom and a chain carbonate,
Monofluoroethylene carbonate and dimethyl carbonate, monofluoroethylene carbonate and diethyl carbonate, monofluoroethylene carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and dimethyl carbonate and diethyl carbonate, monofluoroethylene carbonate and dimethyl carbonate and ethyl methyl carbonate, monofluoro Examples thereof include ethylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate.

Among the combinations of cyclic carbonates having a fluorine atom and chain carbonates, those containing symmetric chain alkyl carbonates as chain carbonates are more preferable, and in particular, monofluoroethylene carbonate, dimethyl carbonate, ethyl methyl carbonate, Cycle characteristics include monofluoroethylene carbonate, symmetric chain carbonates and asymmetric chain carbonates such as fluoroethylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate. And a large current discharge characteristic are preferable. Among these, the symmetric chain carbonate is preferably dimethyl carbonate, and the alkyl group of the chain carbonate preferably has 1 to 2 carbon atoms.

A combination in which a cyclic carbonate having no fluorine atom is further added to the combination of the cyclic carbonate having a fluorine atom and the chain carbonate is also mentioned as a preferable combination. Among them, the total of the cyclic carbonate having a fluorine atom and the cyclic carbonate having no fluorine atom in the non-aqueous solvent is preferably 10% by volume or more, more preferably 15% by volume or more, and further preferably 20% by volume or more. The ratio of the cyclic carbonate having a fluorine atom to the total of the cyclic carbonate having a fluorine atom and the cyclic carbonate having no fluorine atom is 1% by volume or more, preferably 3% by volume or more, more preferably 5% by volume or more. More preferably 10% by volume or more, particularly preferably 20% by volume or more, and preferably 95% by volume or less, more preferably 85% by volume or less, still more preferably 75% by volume or less, particularly preferably 60% by volume. It is as follows.

When the cyclic carbonate having no fluorine atom is contained in this concentration range, the electrical conductivity of the electrolytic solution can be maintained while forming a stable protective film on the negative electrode.
As a specific example of a preferable combination of a cyclic carbonate having a fluorine atom and a cyclic carbonate having no fluorine atom and a chain carbonate,
Monofluoroethylene carbonate, ethylene carbonate and dimethyl carbonate,
Monofluoroethylene carbonate and ethylene carbonate and diethyl carbonate, monofluoroethylene carbonate and ethylene carbonate and ethyl methyl carbonate,
Monofluoroethylene carbonate, ethylene carbonate, dimethyl carbonate and diethyl carbonate, monofluoroethylene carbonate, ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and ethylene Carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, propylene carbonate and dimethyl carbonate, monofluoroethylene carbonate, propylene carbonate and diethyl carbonate, monofluoroethylene carbonate, propylene carbonate and ethyl methyl carbonate Bonate, monofluoroethylene carbonate, propylene carbonate, dimethyl carbonate and diethyl carbonate, monofluoroethylene carbonate, propylene carbonate, dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, propylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate And propylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate,
Monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate And propylene carbonate, dimethyl carbonate and diethyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate and ethyl carbonate. Methyl carbonate, mono-fluoroethylene carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate and diethyl carbonate and ethyl methyl carbonate.

Among the combinations of cyclic carbonates having fluorine atoms and cyclic carbonates not having fluorine atoms and chain carbonates, those containing asymmetric chain alkyl carbonates as chain carbonates are more preferred,
Monofluoroethylene carbonate and ethylene carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and propylene carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and ethylene carbonate and dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and propylene carbonate and dimethyl carbonate Ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, diethyl carbonate, ethyl methyl carbonate, monofluoroethylene carbonate and propylene carbonate Ethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, monofluoroethylene carbonate and propylene carbonate And dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, monofluoroethylene carbonate, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate. Since the balance of Le characteristics and large-current discharge characteristics may preferably. Among them, the asymmetric chain carbonate is preferably ethyl methyl carbonate, and the alkyl group of the chain carbonate preferably has 1 to 2 carbon atoms.

When ethyl methyl carbonate is contained in the non-aqueous solvent, the proportion of ethyl methyl carbonate in the total non-aqueous solvent is preferably 10% by volume or more, more preferably 20% by volume.
Or more, more preferably 25% by volume or more, particularly preferably 30% by volume or more,
When it is contained within the range of preferably 95% by volume or less, more preferably 90% by volume or less, further preferably 85% by volume or less, and particularly preferably 80% by volume or less, the load characteristics of the battery may be improved.
In the combination mainly composed of the cyclic carbonate having a fluorine atom and the chain carbonate, in addition to the cyclic carbonate having no fluorine atom, a cyclic carboxylic acid ester, a chain carboxylic acid ester, a cyclic ether, a chain Other solvents such as a chain ether, a sulfur-containing organic solvent, a phosphorus-containing organic solvent, and a fluorine-containing aromatic solvent may be mixed.

<When using a cyclic carbonate having a fluorine atom as an auxiliary agent>
In the present invention, when a cyclic carbonate having a fluorine atom is used as an auxiliary agent, as the non-aqueous solvent other than the cyclic carbonate having a fluorine atom, the above-exemplified non-aqueous solvent may be used alone, or two or more thereof. May be used in any combination and ratio.
For example, one preferred combination of non-aqueous solvents is a combination mainly composed of a cyclic carbonate having no fluorine atom and a chain carbonate.

Among them, the total of the cyclic carbonate having no fluorine atom and the chain carbonate in the non-aqueous solvent is preferably 70% by volume or more, more preferably 80% by volume or more, further preferably 90% by volume or more, and The ratio of the cyclic carbonate having no fluorine atom to the total of the cyclic carbonate and the chain carbonate is preferably 5% by volume or more, more preferably 10% by volume or more, further preferably 15% by volume or more, and preferably It is 50 volume% or less, More preferably, it is 35 volume% or less, More preferably, it is 30 volume% or less, Most preferably, it is 25 volume% or less.

When a combination of these non-aqueous solvents is used, the balance between the cycle characteristics and high-temperature storage characteristics (particularly, the remaining capacity and high-load discharge capacity after high-temperature storage) of a battery produced using the non-aqueous solvent may be improved.
For example, as a specific example of a preferable combination of a cyclic carbonate having no fluorine atom and a chain carbonate,
Ethylene carbonate and dimethyl carbonate, ethylene carbonate and diethyl carbonate, ethylene carbonate and ethyl methyl carbonate, ethylene carbonate and dimethyl carbonate and diethyl carbonate, ethylene carbonate and dimethyl carbonate and ethyl methyl carbonate, ethylene carbonate and diethyl carbonate and ethyl methyl carbonate, ethylene carbonate And dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, propylene carbonate and ethyl methyl carbonate, propylene carbonate, ethyl methyl carbonate and diethyl carbonate, propylene carbonate, ethyl methyl carbonate and dimethyl carbonate.

Among the combinations of cyclic carbonates having no fluorine atoms and chain carbonates, those containing asymmetric chain alkyl carbonates as chain carbonates are more preferable, and in particular, ethylene carbonate and ethyl methyl carbonate, propylene carbonate and ethyl Methyl carbonate, ethylene carbonate and ethyl methyl carbonate and dimethyl carbonate, ethylene carbonate and ethyl methyl carbonate and diethyl carbonate, propylene carbonate, ethyl methyl carbonate and dimethyl carbonate,
Propylene carbonate, ethyl methyl carbonate, and diethyl carbonate are preferred because of a good balance between cycle characteristics and large current discharge characteristics.

Among them, it is preferable that the asymmetric chain carbonate is ethyl methyl carbonate,
The alkyl group of the chain carbonate preferably has 1 to 2 carbon atoms.
When dimethyl carbonate is contained in the non-aqueous solvent, the proportion of dimethyl carbonate in the total non-aqueous solvent is preferably 10% by volume or more, more preferably 20% by volume or more, and even more preferably 25% by volume or more. Preferably, it is 30% by volume or more, preferably 90% by volume or less, more preferably 80% by volume or less, still more preferably 75% by volume or less,
Particularly preferably, when it is contained in a range of 70% by volume or less, the load characteristics of the battery may be improved.

Above all, it contains dimethyl carbonate and ethyl methyl carbonate, and by increasing the content ratio of dimethyl carbonate over the content ratio of ethyl methyl carbonate, the electric conductivity of the electrolyte can be maintained, but the battery characteristics after high temperature storage are improved. This is preferable.
The volume ratio of dimethyl carbonate to ethyl methyl carbonate in all non-aqueous solvents (dimethyl carbonate / ethyl methyl carbonate) is 1.1 or more in terms of improving the electric conductivity of the electrolyte and improving the battery characteristics after storage. Is preferable, 1.5 or more is more preferable, and 2.5 or more is more preferable. The volume ratio (dimethyl carbonate / ethyl methyl carbonate) is preferably 40 or less, more preferably 20 or less, still more preferably 10 or less, and particularly preferably 8 or less, from the viewpoint of improving battery characteristics at low temperatures.

In the combination mainly composed of a cyclic carbonate having no fluorine atom and a chain carbonate, a cyclic carboxylic acid ester, a chain carboxylic acid ester, a cyclic ether, a chain ether, a sulfur-containing organic solvent, a phosphorus-containing solvent You may mix other solvents, such as an organic solvent and an aromatic fluorine-containing solvent.
In this specification, the volume of the non-aqueous solvent is a measured value at 25 ° C., but the measured value at the melting point is used for a solid at 25 ° C. such as ethylene carbonate.

1-4. Auxiliary agent In the non-aqueous electrolyte battery of the present invention, a compound comprising a structure represented by the following general formula (A):
And 0 with respect to the total amount of the nitrile compound, isocyanate compound, difluorophosphate, fluorosulfonate, lithium bis (fluorosulfonyl) imide, the compound represented by the following general formula (B), and the non-aqueous electrolyte solution In addition to at least one compound selected from the group consisting of cyclic carbonate compounds having a fluorine atom of 0.01 mass% or more and 50 mass% or less, an auxiliary agent may be appropriately used depending on the purpose. As the auxiliary agent, the following cyclic carbonate having a carbon-carbon unsaturated bond, an acid anhydride compound, a vinyl sulfonate compound,
Aromatic compounds having 12 or less carbon atoms, fluorinated unsaturated cyclic carbonates, compounds having triple bonds, other auxiliaries, etc., cyclic carbonates having carbon-carbon unsaturated bonds,
Acid anhydride compounds are preferred.

1-4-1. Cyclic carbonate having a carbon-carbon unsaturated bond Cyclic carbonate having a carbon-carbon unsaturated bond (hereinafter, “unsaturated cyclic carbonate”)
As long as it is a cyclic carbonate having a carbon-carbon double bond or a carbon-carbon triple bond, any unsaturated carbonate can be used. The cyclic carbonate having an aromatic ring is also included in the unsaturated cyclic carbonate.

As unsaturated cyclic carbonate,
Examples include vinylene carbonates, ethylene carbonates substituted with an aromatic ring or a substituent having a carbon-carbon double bond or carbon-carbon triple bond, phenyl carbonates, vinyl carbonates, allyl carbonates, catechol carbonates, and the like. .

As vinylene carbonates,
Vinylene carbonate, methyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, phenyl vinylene carbonate, 4,5-diphenyl vinylene carbonate,
Vinyl vinylene carbonate, 4,5-divinyl vinylene carbonate, allyl vinylene carbonate, 4,5-diallyl vinylene carbonate, 4-fluoro vinylene carbonate, 4-fluoro-5-methyl vinylene carbonate, 4-fluoro-5-phenyl vinylene carbonate, 4-Fluoro-5-vinyl vinylene carbonate, 4-allyl-5
-Fluoro vinylene carbonate etc. are mentioned.

Specific examples of ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon double bond or a carbon-carbon triple bond include:
Vinylethylene carbonate, 4,5-divinylethylene carbonate, 4-methyl-
5-vinylethylene carbonate, 4-allyl-5-vinylethylene carbonate, ethynylethylene carbonate, 4,5-diethynylethylene carbonate, 4-methyl-5
-Ethynylethylene carbonate, 4-vinyl-5-ethynylethylene carbonate, 4
-Allyl-5-ethynylethylene carbonate, phenylethylene carbonate, 4,5
-Diphenylethylene carbonate, 4-phenyl-5-vinylethylene carbonate,
4-allyl-5-phenylethylene carbonate, allylethylene carbonate, 4,5
-Diallylethylene carbonate, 4-methyl-5-allylethylene carbonate, etc. are mentioned.

Among these, as an unsaturated cyclic carbonate particularly preferable for use in combination with the compound represented by the formula (1),
Vinylene carbonate, methyl vinylene carbonate, 4,5-dimethyl vinylene carbonate, vinyl vinylene carbonate, 4,5-vinyl vinylene carbonate, allyl vinylene carbonate, 4,5-diallyl vinylene carbonate, vinyl ethylene carbonate, 4,5-divinyl ethylene carbonate 4-methyl-5-vinylethylene carbonate, allylethylene carbonate, 4,5-diallylethylene carbonate, 4-
Methyl-5-allylethylene carbonate, 4-allyl-5-vinylethylene carbonate, ethynylethylene carbonate, 4,5-diethynylethylene carbonate, 4-methyl-5-ethynylethylene carbonate, 4-vinyl-5-ethynylethylene carbonate Is mentioned. Vinylene carbonate, vinyl ethylene carbonate, and ethynyl ethylene carbonate are particularly preferable because they form a more stable interface protective film.

The molecular weight of the unsaturated cyclic carbonate is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired. The molecular weight is preferably 80 or more and 250 or less. If it is this range, it will be easy to ensure the solubility of the unsaturated cyclic carbonate with respect to a non-aqueous electrolyte solution, and the effect of this invention will fully be expressed easily. The molecular weight of the unsaturated cyclic carbonate is more preferably 85
It is above, More preferably, it is 150 or less.

The production method of the unsaturated cyclic carbonate is not particularly limited, and can be produced by arbitrarily selecting a known method.
An unsaturated cyclic carbonate may be used individually by 1 type, or may use 2 or more types together by arbitrary combinations and a ratio. Moreover, the compounding quantity of unsaturated cyclic carbonate is not restrict | limited in particular, As long as the effect of this invention is not impaired remarkably, it is arbitrary. The blending amount of the unsaturated cyclic carbonate is preferably 0.001% by mass or more, more preferably 0.0% in 100% by mass of the non-aqueous electrolyte solution.
1 mass% or more, More preferably, it is 0.1 mass% or more, Preferably it is 5 mass% or less, More preferably, it is 4 mass% or less, More preferably, it is 3 mass% or less. Within this range, the non-aqueous electrolyte battery tends to exhibit a sufficient cycle characteristics improvement effect, and the high temperature storage characteristics are reduced, the amount of gas generated is increased, and the discharge capacity maintenance ratio is reduced. Easy to avoid.

1-4-2. Acid anhydride compound Acid anhydride compounds include carboxylic acid anhydride, sulfuric acid anhydride, nitric acid anhydride, sulfonic acid anhydride, phosphoric acid anhydride, phosphorous acid anhydride, cyclic acid anhydride, chain The structure is not particularly limited as long as it is an acid anhydride compound.

Specific examples of the acid anhydride compound include, for example,
Malonic anhydride, succinic anhydride, glutaric anhydride, adipic anhydride, maleic anhydride, citraconic anhydride, 2,3-dimethylmaleic anhydride, glutaconic anhydride, itaconic anhydride, phthalic anhydride, phenylmaleic anhydride 2,3-diphenylmaleic anhydride, cyclohexane-1,2-dicarboxylic anhydride, 4-cyclohexene-1,2-dicarboxylic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, 4 , 4'-oxydiphthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, methyl-5-norbornene-2
, 3-dicarboxylic acid anhydride, phenylsuccinic acid anhydride, 2-phenylglutaric acid anhydride,
Allyl succinic anhydride, 2-buten-11-yl succinic anhydride, (2-methyl-2-propenyl) succinic anhydride, tetrafluorosuccinic anhydride, diacetyl-tartaric anhydride, bicyclo [2.
2.2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2- Dicarboxylic anhydride, methacrylic anhydride, acrylic anhydride, crotonic anhydride, methanesulfonic anhydride, trifluoromethanesulfonic anhydride, nonafluorobutanesulfonic anhydride,
Examples include acetic anhydride.

Of these,
Succinic anhydride, maleic anhydride, citraconic anhydride, phenylmaleic anhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 5- (2 ,
5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, allyl succinic anhydride, acetic anhydride, methacrylic anhydride, acrylic anhydride, methanesulfonic anhydride Particularly preferred.

An acid anhydride compound may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
There is no limitation on the amount of the acid anhydride compound with respect to the entire non-aqueous electrolyte solution of the present invention, and it is optional as long as the effect of the present invention is not significantly impaired.
1% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably It is contained at a concentration of 2% by mass or less, particularly preferably 1% by mass or less, and most preferably 0.5% by mass or less.
When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, and high temperature storage characteristics are further improved.

1-4-4. Vinyl sulfonic acid ester compound The type of vinyl sulfonic acid ester compound is not particularly limited as long as it is a compound having a vinyl sulfonic acid ester structure in the molecule.
Specific examples of the vinyl sulfonate compound include, for example,

Above all,

Is preferred.
A vinyl sulfonic acid ester compound may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. There is no restriction | limiting in the compounding quantity of the vinyl sulfonic acid ester compound with respect to the whole non-aqueous electrolyte solution of this invention, and it is arbitrary unless the effect of this invention is impaired remarkably, but with respect to the non-aqueous electrolyte solution of this invention, it is usually 0.00. 001% by mass or more, preferably 0.01
% By mass or more, more preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 2% by mass or less, and particularly preferably 1% by mass. % Or less, most preferably 0.5% by mass or less. When the above range is satisfied, effects such as output characteristics, load characteristics, low temperature characteristics, cycle characteristics, and high temperature storage characteristics are further improved.

1-4-5. Aromatic compound having 12 or less carbon atoms The aromatic compound having 12 or less carbon atoms is not particularly limited as long as it is a compound having 12 or less carbon atoms in the molecule.
As a specific example of an aromatic compound having 12 or less carbon atoms, for example,
Biphenyl, alkylbiphenyl, cyclohexylbenzene, t-butylbenzene, t
-Aromatic compounds such as amylbenzene, diphenyl ether, dibenzofuran; partially fluorinated products of the above aromatic compounds such as 2-fluorobiphenyl, o-cyclohexylfluorobenzene, p-cyclohexylfluorobenzene;
Examples thereof include fluorine-containing anisole compounds such as 2,4-difluoroanisole, 2,5-difluoroanisole, 2,6-difluoroanisole, and 3,5-difluoroanisole. Above all,
Biphenyl, alkylbiphenyl, cyclohexylbenzene, t-butylbenzene, t
-Aromatic compounds such as amylbenzene, diphenyl ether and dibenzofuran are preferred.

These may be used alone or in combination of two or more. When two or more kinds are used in combination, in particular, a combination of cyclohexylbenzene and t-butylbenzene or t-amylbenzene, aroma not containing oxygen such as biphenyl, alkylbiphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, etc. It is preferable to use at least one selected from group compounds and at least one selected from oxygen-containing aromatic compounds such as diphenyl ether and dibenzofuran from the viewpoint of the balance of high-temperature storage characteristics.

The aromatic compound having 12 or less carbon atoms is not particularly limited, and is arbitrary as long as the effects of the present invention are not significantly impaired. The overcharge inhibitor is usually 0.001% by mass in 100% by mass of the non-aqueous electrolyte.
Or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 1%
It is contained at a concentration of 0% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, further preferably 2% by mass or less, and particularly preferably 1% by mass or less. Within this range,
The effect of the overcharge preventing agent is easily exhibited, and it is easy to avoid a situation in which battery characteristics such as high-temperature storage characteristics deteriorate.

1-4-6. Chain carboxylic acid ester As the chain carboxylic acid ester, one having 3 to 7 carbon atoms is preferable. Specifically, methyl acetate, ethyl acetate, acetic acid-n-propyl, isopropyl acetate, acetic acid-n-butyl, isobutyl acetate, acetic acid-t-butyl, methyl propionate, ethyl propionate, propionate-n-propyl, Isopropyl propionate, n-butyl propionate, isobutyl propionate, t-butyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, methyl isobutyrate, ethyl isobutyrate, isobutyric acid-n- Propyl,
Examples include isopropyl isobutyrate.

Among them, methyl acetate, ethyl acetate, acetate-n-propyl, acetate-n-butyl, methyl propionate, ethyl propionate, propionate-n-propyl, isopropyl propionate, methyl butyrate, ethyl butyrate, etc. It is preferable from the viewpoint of improvement of ionic conductivity. More preferably, methyl propionate, ethyl propionate, propionic acid-n-
Propyl and isopropyl propionate, particularly preferably methyl propionate and ethyl propionate are preferred.

A chain carboxylic acid ester may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
The amount of the chain carboxylic acid ester is usually 100% by volume in the non-aqueous solvent, preferably 10%.
It is at least 15% by volume, more preferably at least 15% by volume. By setting the lower limit in this way,
The electric conductivity of the non-aqueous electrolyte solution is improved, and the large current discharge characteristics of the non-aqueous electrolyte battery are easily improved. The amount of the chain carboxylic acid ester is 100% by volume in the non-aqueous solvent, preferably 60% by volume or less, more preferably 50% by volume or less, still more preferably 30% by volume or less,
Especially preferably, it is 20 volume% or less, Most preferably, it is 10 volume% or less. By setting the upper limit in this way, an increase in negative electrode resistance is suppressed, and the large current discharge characteristics and cycle characteristics of the non-aqueous electrolyte battery are easily set in a favorable range.

1-4-6. Fluorinated unsaturated cyclic carbonate As the fluorinated cyclic carbonate, it is also preferable to use a cyclic carbonate having an unsaturated bond and a fluorine atom (hereinafter sometimes referred to as “fluorinated unsaturated cyclic carbonate”). If the number of fluorine atoms in the fluorinated unsaturated cyclic carbonate is 1 or more,
There is no particular limitation. Among them, the fluorine atom is usually 6 or less, preferably 4 or less, and 1 or 2
Is most preferred.

Examples of the fluorinated unsaturated cyclic carbonate include fluorinated vinylene carbonate derivatives, fluorinated ethylene carbonate derivatives substituted with an aromatic ring or a substituent having a carbon-carbon double bond.
As a fluorinated vinylene carbonate derivative, 4-fluoro vinylene carbonate,
Examples include 4-fluoro-5-methyl vinylene carbonate, 4-fluoro-5-phenyl vinylene carbonate, 4-allyl-5-fluoro vinylene carbonate, 4-fluoro-5-vinyl vinylene carbonate.

As the fluorinated ethylene carbonate derivative substituted with a substituent having an aromatic ring or a carbon-carbon double bond,
4-fluoro-4-vinylethylene carbonate, 4-fluoro-4-allylethylene carbonate, 4-fluoro-5-vinylethylene carbonate, 4-fluoro-5-allylethylene carbonate, 4,4-difluoro-4-vinylethylene Carbonate, 4
, 4-Difluoro-4-allylethylene carbonate, 4,5-difluoro-4-vinylethylene carbonate, 4,5-difluoro-4-allylethylene carbonate, 4-fluoro-4,5-divinylethylene carbonate, 4-fluoro -4,5-diallylethylene carbonate, 4,5-difluoro-4,5-divinylethylene carbonate, 4,
5-difluoro-4,5-diallylethylene carbonate, 4-fluoro-4-phenylethylene carbonate, 4-fluoro-5-phenylethylene carbonate, 4,4-difluoro-5-phenylethylene carbonate, 4,5-difluoro- 4-phenylethylene carbonate etc. are mentioned.

Among these, as a preferable fluorinated unsaturated cyclic carbonate,
4-fluoro vinylene carbonate, 4-fluoro-5-methyl vinylene carbonate, 4-fluoro-5-vinyl vinylene carbonate, 4-allyl-5-fluoro vinylene carbonate, 4-fluoro-4-vinyl ethylene carbonate, 4-fluoro- 4-allylethylene carbonate, 4-fluoro-5-vinylethylene carbonate, 4-fluoro-5-allylethylene carbonate, 4,4-difluoro-4-vinylethylene carbonate, 4,4-difluoro-4-allylethylene carbonate, 4,5-difluoro-4-vinylethylene carbonate, 4,5-difluoro-4-allylethylene carbonate, 4-fluoro-4,5-divinylethylene carbonate, 4-fluoro-4,5-
Diallylethylene carbonate, 4,5-difluoro-4,5-divinylethylene carbonate, and 4,5-difluoro-4,5-diallylethylene carbonate are more preferably used because they form a stable interface protective film.

The molecular weight of the fluorinated unsaturated cyclic carbonate is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired. The molecular weight is preferably 50 or more and 250 or less. If it is this range, it will be easy to ensure the solubility of the fluorinated cyclic carbonate with respect to a non-aqueous electrolyte solution, and the effect of this invention will be easy to be expressed.
The production method of the fluorinated unsaturated cyclic carbonate is not particularly limited, and can be produced by arbitrarily selecting a known method. The molecular weight is more preferably 100 or more, and more preferably 200 or less.

A fluorinated unsaturated cyclic carbonate may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. Moreover, the compounding quantity of a fluorinated unsaturated cyclic carbonate is not restrict | limited in particular, As long as the effect of this invention is not impaired remarkably, it is arbitrary.
The blending amount of the fluorinated unsaturated cyclic carbonate is usually 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.1% by mass in 100% by mass of the non-aqueous electrolyte solution.
5% by mass or more, preferably 10% by mass or less, more preferably 5% by mass or less,
More preferably, it is 3 mass% or less, Most preferably, it is 2 mass% or less.
Within this range, the non-aqueous electrolyte battery tends to exhibit a sufficient cycle characteristics improvement effect, and the high temperature storage characteristics deteriorate, the amount of gas generated increases, and the discharge capacity maintenance ratio decreases. Easy to avoid.

1-4-7. Compound having triple bond The compound having a triple bond is not particularly limited as long as it is a compound having one or more triple bonds in the molecule.
Specific examples of the compound having a triple bond include the following compounds.
1-pentyne, 2-pentyne, 1-hexyne, 2-hexyne, 3-hexyne, 1-heptin, 2-heptin, 3-heptin, 1-octyne, 2-octyne, 3-octyne, 4-
Octyne, 1-nonine, 2-nonine, 3-nonine, 4-nonine, 1-dodecin, 2-dodecin, 3-dodecin, 4-dodecin, 5-dodecin, phenylacetylene, 1-phenyl-1-propyne, 1 -Phenyl-2-propyne, 1-phenyl-1-butyne, 4-phenyl-1-butyne, 4-phenyl-1-butyne, 1-phenyl-1-pentyne, 5-phenyl-1-pentyne, 1-phenyl Hydrocarbon compounds such as -1-hexyne, 6-phenyl-1-hexyne, diphenylacetylene, 4-ethynyltoluene, dicyclohexylacetylene;

2-propynylmethyl carbonate, 2-propynylethyl carbonate, 2-propynylpropyl carbonate, 2-propynylbutyl carbonate, 2-propynylphenyl carbonate, 2-propynylcyclohexyl carbonate, di-2-propynyl carbonate, 1-methyl-2-propynyl Methyl carbonate, 1,1-dimethyl-2-propynylmethyl carbonate, 2-butynylmethyl carbonate, 3-butynylmethyl carbonate, 2-pentynylmethyl carbonate, 3-pentynylmethyl carbonate,
Monocarbonates such as 4-pentynylmethyl carbonate;
2-butyne-1,4-diol dimethyl dicarbonate, 2-butyne-1,4-diol diethyl dicarbonate, 2-butyne-1,4-diol dipropyl dicarbonate, 2-butyne-1,4-diol dibutyl Dicarbonate, 2-butyne-1,4-
Dicarbonates such as diol diphenyl dicarbonate and 2-butyne-1,4-diol dicyclohexyl dicarbonate;

2-propynyl acetate, 2-propynyl propionate, 2-propynyl butyrate, benzoic acid 2
-Propynyl, 2-propynyl cyclohexylcarboxylate, acetic acid 1,1-dimethyl-2-
Propynyl, propionic acid 1,1-dimethyl-2-propynyl, butyric acid 1,1-dimethyl-
2-propynyl, benzoic acid 1, 1-dimethyl-2-propynyl, cyclohexylcarboxylic acid 1, 1-dimethyl-2-propynyl, 2-butynyl acetate, 3-butynyl acetate, 2-acetate
Pentynyl, 3-pentynyl acetate, 4-pentynyl acetate, methyl acrylate, ethyl acrylate, propyl acrylate, vinyl acrylate, 2-propenyl acrylate, 2-butenyl acrylate, 3-butenyl acrylate, methyl methacrylate, Ethyl methacrylate,
Propyl methacrylate, vinyl methacrylate, 2-propenyl methacrylate, 2-butenyl methacrylate, 3-butenyl methacrylate, methyl 2-propinate, ethyl 2-propinate, propyl 2-propinate, vinyl 2-propinate, 2-propenyl 2-propenylate, 2-butenyl 2-propanoate, 3-butenyl 2-propanoate, methyl 2-butyrate, 2
-Ethyl butyrate, propyl 2-butyrate, vinyl 2-butyrate, 2-propenyl 2-butyrate, 2-butenyl 2-butynoate, 3-butenyl 2-butynoate, methyl 3-butyrate,
3-butynoic acid ethyl, 3-butynoic acid propyl, 3-butynoic acid vinyl, 3-butynoic acid 2-propenyl, 3-butynoic acid 2-butenyl, 3-butynoic acid 3-butenyl, 2-pentynoic acid methyl, 2- Ethyl pentinate, propyl 2-pentinate, vinyl 2-pentinate, 2-propenyl 2-pentinate, 2-butenyl 2-pentinate, 3-butenyl 2-pentinate, 3
-Methyl pentinate, ethyl 3-pentinate, propyl 3-pentinate, vinyl 3-pentinate, 2-propenyl 3-pentinate, 2-butenyl 3-pentinate, 3-butenyl 3-pentinate, 4-pentyne Monocarboxylic acid esters such as methyl acid, ethyl 4-pentynoate, propyl 4-pentynoate, vinyl 4-pentynoate, 2-propenyl 4-pentynoate, 2-butenyl 4-pentynoate and 3-butenyl 4-pentynoate ;

2-butyne-1,4-diol diacetate, 2-butyne-1,4-diol dipropionate, 2-butyne-1,4-diol dibutyrate, 2-butyne-1,4-diol dibenzoate, 2-butyne Dicarboxylic acid esters such as -1,4-diol dicyclohexanecarboxylate;
Methyl oxalate 2-propynyl, ethyl oxalate 2-propynyl, propyl oxalate 2-propynyl, 2-propynyl oxalate vinyl, allyl oxalate 2-propynyl, di-2-propynyl oxalate, 2-butynyl methyl oxalate, 2-butynyl ethyl oxalate, 2-butynylpropyl oxalate, 2-butynyl vinyl oxalate, allyl 2-butynyl oxalate, di-2-butynyl oxalate, 3-butynyl methyl oxalate,
Oxalic acid diesters such as ethyl 3-butynyl oxalate, 3-butynylpropyl oxalate, 3-butynyl vinyl oxalate, allyl 3-butynyl oxalate, di-3-butynyl oxalate;

Methyl (2-propynyl) (vinyl) phosphine oxide, divinyl (2-propynyl) phosphine oxide, di (2-propynyl) (vinyl) phosphine oxide, di (2-
Propenyl) 2 (-propynyl) phosphine oxide, di (2-propynyl) (2-propenyl) phosphine oxide, di (3-butenyl) (2-propynyl) phosphine oxide, and di (2-propynyl) (3-butenyl) Phosphine oxides such as phosphine oxide;
2-propynyl methyl (2-propenyl) phosphinate, 2-propynyl 2-butenyl (methyl) phosphinate, 2-propynyl di (2-propenyl) phosphinate, di (3-
Butenyl) phosphinic acid 2-propynyl, methyl (2-propenyl) phosphinic acid 1,1
-Dimethyl-2-propynyl, 2-butenyl (methyl) phosphinic acid 1,1-dimethyl-
2-propynyl, 1,1-dimethyl-2-propynyl di (2-propenyl) phosphinate, and 1,1-dimethyl-2-propynyl di (3-butenyl) phosphinate, methyl (2
-Propynyl) phosphinic acid 2-propenyl, methyl (2-propynyl) phosphinic acid 3
-Butenyl, di (2-propynyl) phosphinic acid 2-propenyl, di (2-propynyl)
Phosphinic acid esters such as 3-butenyl phosphinate, 2-propenyl (2-propenyl) phosphinic acid 2-propenyl, and 2-propynyl (2-propenyl) phosphinic acid 3-butenyl;

Methyl 2-propenylphosphonate 2-propynyl, methyl 2-butenylphosphonate (
2-propynyl), 2-propenylphosphonic acid (2-propynyl) (2-propenyl),
3-butenylphosphonic acid (3-butenyl) (2-propynyl), 2-propenylphosphonic acid (1,1-dimethyl-2-propynyl) (methyl), 2-butenylphosphonic acid (1,1
-Dimethyl-2-propynyl) (methyl), 2-propenylphosphonic acid (1,1-dimethyl-2-propynyl) (2-propenyl), and 3-butenylphosphonic acid (3-butenyl) (1,1-dimethyl- 2-propynyl), methylphosphonic acid (2-propynyl) (2-
Propenyl), methylphosphonic acid (3-butenyl) (2-propynyl), methylphosphonic acid (1,1-dimethyl-2-propynyl) (2-propenyl), methylphosphonic acid (3-
Butenyl) (1,1-dimethyl-2-propynyl), ethylphosphonic acid (2-propynyl) (2-propenyl), ethylphosphonic acid (3-butenyl) (2-propynyl), ethylphosphonic acid (1,1- Phosphonic acid esters such as dimethyl-2-propynyl) (2-propenyl) and ethylphosphonic acid (3-butenyl) (1,1-dimethyl-2-propynyl);

Phosphoric acid (methyl) (2-propenyl) (2-propynyl), phosphoric acid (ethyl) (2-propenyl) (2-propynyl), phosphoric acid (2-butenyl) (methyl) (2-propynyl)
, Phosphoric acid (2-butenyl) (ethyl) (2-propynyl), phosphoric acid (1,1-dimethyl-
2-propynyl) (methyl) (2-propenyl), phosphoric acid (1,1-dimethyl-2-propynyl) (ethyl) (2-propenyl), phosphoric acid (2-butenyl) (1,1-dimethyl-
Phosphate esters such as 2-propynyl) (methyl) and phosphoric acid (2-butenyl) (ethyl) (1,1-dimethyl-2-propynyl);
Among these, a compound having an alkynyloxy group is preferable because it forms a negative electrode film more stably in the electrolytic solution.

further,
2-propynylmethyl carbonate, di-2-propynyl carbonate, 2-butyne-
1,4-diol dimethyl dicarbonate, 2-propynyl acetate, 2-butyne-1,4
-Diol diacetate, methyl oxalate 2-propynyl, di-2-propynyl oxalate and the like are particularly preferred from the standpoint of improving storage characteristics.

The said compound which has a triple bond may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. The compounding amount of the compound having a triple bond with respect to the entire non-aqueous electrolyte solution of the present invention is not limited, and is arbitrary as long as the effects of the present invention are not significantly impaired. 01% by mass or more, preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and usually 5% by mass or less, preferably 3% by mass or less, more preferably 1% by mass or less Let If the above range is satisfied, the output characteristics,
Effects such as load characteristics, low temperature characteristics, cycle characteristics, and high temperature storage characteristics are further improved.

1-4-8. Other auxiliaries As other auxiliaries, known auxiliaries other than the above auxiliaries can be used. As other auxiliaries,
Carbonate compounds such as erythritan carbonate, spiro-bis-dimethylene carbonate, methoxyethyl-methyl carbonate;
2,4,8,10-tetraoxaspiro [5.5] undecane, 3,9-divinyl-2
, 4,8,10-tetraoxaspiro [5.5] undecane and other spiro compounds;
Ethylene sulfite, methyl fluorosulfonate, ethyl fluorosulfonate, methyl methanesulfonate, ethyl methanesulfonate, busulfan, sulfolene, diphenylsulfone, N, N-dimethylmethanesulfonamide, N, N-diethylmethanesulfonamide, vinyl Methyl sulfonate, ethyl vinyl sulfonate, allyl vinyl sulfonate, propargyl vinyl sulfonate, methyl allyl sulfonate, ethyl allyl sulfonate, allyl sulfonate, propargyl allyl sulfonate, 1,2-bis (vinylsulfonoxy) Sulfur-containing compounds such as ethane;

Nitrogen-containing compounds such as 1-methyl-2-pyrrolidinone, 1-methyl-2-piperidone, 3-methyl-2-oxazolidinone, 1,3-dimethyl-2-imidazolidinone and N-methylsuccinimide;
Trimethyl phosphite, triethyl phosphite, triphenyl phosphite, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, dimethyl methylphosphonate, diethyl ethylphosphonate, dimethyl vinylphosphonate, diethyl vinylphosphonate, dimethylphosphine Phosphorus-containing compounds such as methyl acid, ethyl diethylphosphinate, trimethylphosphine oxide, triethylphosphine oxide;

Hydrocarbon compounds such as heptane, octane, nonane, decane, cycloheptane;
Fluorine-containing aromatic compounds such as fluorobenzene, difluorobenzene, hexafluorobenzene and benzotrifluoride;
Etc. These may be used alone or in combination of two or more. By adding these auxiliaries, capacity maintenance characteristics and cycle characteristics after high temperature storage can be improved.

The blending amount of other auxiliary agents is not particularly limited, and is arbitrary as long as the effects of the present invention are not significantly impaired. The other auxiliary agent is preferably 0.01% by mass or more and 5% by mass or less in 100% by mass of the non-aqueous electrolyte solution. Within this range, the effects of other auxiliaries can be sufficiently exhibited, and it is easy to avoid a situation in which battery characteristics such as high-load discharge characteristics deteriorate.
The amount of other auxiliaries is more preferably 0.1% by mass or more, and still more preferably 0.2%.
It is at least mass%, more preferably at most 3 mass%, still more preferably at most 1 mass%.

As mentioned above, what exists in the inside of the non-aqueous electrolyte battery as described in this invention is also contained in the above-mentioned non-aqueous electrolyte.
Specifically, the components of the non-aqueous electrolyte solution such as lithium salt, solvent, and auxiliary agent are separately synthesized, and the non-aqueous electrolyte solution is prepared from what is substantially isolated by the method described below. In the case of a nonaqueous electrolyte solution in a nonaqueous electrolyte battery obtained by pouring into a separately assembled battery, the components of the nonaqueous electrolyte solution of the present invention are individually placed in the battery, In order to obtain the same composition as the non-aqueous electrolyte solution of the present invention by mixing in a non-aqueous electrolyte battery, the compound constituting the non-aqueous electrolyte solution of the present invention is further generated in the non-aqueous electrolyte battery. The case where the same composition as the aqueous electrolyte is obtained is also included.

2. Battery Configuration The non-aqueous electrolyte battery of the present invention is suitable for use as an electrolyte for a secondary battery, for example, a lithium secondary battery, among non-aqueous electrolyte batteries. Hereinafter, a non-aqueous electrolyte battery using the non-aqueous electrolyte of the present invention will be described.
The non-aqueous electrolyte battery of the present invention can adopt a known structure. Typically, the negative electrode and the positive electrode capable of occluding and releasing ions (for example, lithium ions), and the non-aqueous electrolysis of the present invention described above. Liquid.

2-1. Negative electrode The negative electrode active material used for the negative electrode is described below. The negative electrode active material is not particularly limited as long as it can electrochemically occlude and release lithium ions. As a specific example,
Examples thereof include carbonaceous materials, alloy materials, and lithium-containing metal composite oxide materials. These are 1
You may use a seed | species independently and may use it combining 2 or more types arbitrarily.

<Negative electrode active material>
Examples of the negative electrode active material include carbonaceous materials, alloy materials, lithium-containing metal composite oxide materials, and the like.
Examples of the carbonaceous material include (1) natural graphite, (2) artificial graphite, (3) amorphous carbon, (4) carbon-coated graphite, (5) graphite-coated graphite, and (6) resin-coated graphite. .

(1) Examples of natural graphite include scaly graphite, scaly graphite, soil graphite, and / or graphite particles obtained by subjecting these graphites to spheroidization or densification. Among these, spherical or ellipsoidal graphite subjected to spheroidizing treatment is particularly preferable from the viewpoints of particle filling properties and charge / discharge rate characteristics.
As an apparatus used for the spheroidization treatment, for example, an apparatus that repeatedly gives mechanical action such as compression, friction, shearing force, etc. including the interaction of particles mainly with impact force to the particles can be used.
Specifically, it has a rotor with a large number of blades installed inside the casing, and mechanical action such as impact compression, friction, shearing force, etc. on the carbon material introduced inside the rotor by rotating at high speed. And a device for performing the spheroidizing treatment is preferable. Moreover, it is preferable to have a mechanism that repeatedly gives mechanical action by circulating the carbon material.

For example, when the spheroidizing process is performed using the above-described apparatus, the peripheral speed of the rotating rotor is set to 30 to 30.
It is preferably 100 m / sec, more preferably 40 to 100 m / sec, and 50 to
More preferably, the speed is 100 m / second. Further, the treatment can be performed by simply passing the carbonaceous material, but it is preferable to circulate or stay in the apparatus for 30 seconds or longer, and it is preferable to circulate or stay in the apparatus for 1 minute or longer. More preferred.

(2) Artificial graphite includes coal tar pitch, coal heavy oil, atmospheric residue, petroleum heavy oil, aromatic hydrocarbon, nitrogen-containing cyclic compound, sulfur-containing cyclic compound, polyphenylene, polyvinyl chloride, Organic compounds such as polyvinyl alcohol, polyacrylonitrile, polyvinyl butyral, natural polymer, polyphenylene sulfide, polyphenylene oxide, furfuryl alcohol resin, phenol-formaldehyde resin, imide resin are usually 2
Graphitized at a temperature in the range of 500 ° C. or higher and usually 3200 ° C. or lower, and pulverized and / or classified as necessary. At this time, a silicon-containing compound or a boron-containing compound can also be used as a graphitization catalyst. In addition, artificial graphite obtained by graphitizing mesocarbon microbeads separated in the heat treatment process of pitch can be mentioned. Furthermore, the artificial graphite of the granulated particle which consists of primary particles is also mentioned. For example, by mixing mesocarbon microbeads and graphitizable carbonaceous material powders such as coke, graphitizable binders such as tar and pitch, and graphitization catalyst, graphitizing, and pulverizing as necessary Examples of the resulting graphite particles include a plurality of flat particles and aggregated or bonded so that the orientation planes are non-parallel.

(3) As amorphous carbon, an easily graphitizable carbon precursor such as tar or pitch is used as a raw material,
Examples include amorphous carbon particles that have been heat-treated at least once in a temperature range (400 to 2200 ° C.) that is not graphitized, and amorphous carbon particles that have been heat-treated using a non-graphitizable carbon precursor such as a resin as a raw material. It is done.

(4) Carbon-coated graphite can be obtained by mixing natural graphite and / or artificial graphite with a carbon precursor that is an organic compound such as tar, pitch, or resin, and heat-treating it at least once in the range of 400 to 2300 ° C. Examples thereof include a carbon graphite composite in which natural graphite and / or artificial graphite is used as nuclear graphite, and amorphous carbon coats the nuclear graphite. The composite form may cover the entire surface or a part thereof, or may be a composite of a plurality of primary particles using carbon originating from the carbon precursor as a binder. In addition, benzene, toluene, methane, propane, aromatic hydrocarbons and other hydrocarbon gases react with natural graphite and / or artificial graphite at high temperatures to deposit carbon on the graphite surface (CVD)
It is also possible to obtain a carbon graphite composite.

(5) As graphite-coated graphite, natural graphite and / or artificial graphite and a carbon precursor of an easily graphitizable organic compound such as tar, pitch or resin are mixed and once in a range of about 2400 to 3200 ° C. Examples thereof include graphite-coated graphite in which natural graphite and / or artificial graphite obtained by heat treatment is used as nuclear graphite, and graphitized material covers the whole or part of the surface of nuclear graphite.
(6) As resin-coated graphite, natural graphite and / or artificial graphite and resin are mixed, 400
Examples thereof include resin-coated graphite in which natural graphite and / or artificial graphite obtained by drying at a temperature of less than 0 ° C. is used as nuclear graphite, and a resin or the like is coated with nuclear graphite.

Moreover, the carbonaceous material of (1)-(6) may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.
Examples of organic compounds such as tar, pitch and resin used in the above (2) to (5) include coal-based heavy oil, direct-current heavy oil, cracked heavy petroleum oil, aromatic hydrocarbon, N-ring compound. , S ring compound, polyphenylene, organic synthetic polymer, natural polymer, thermoplastic resin and carbonizable organic compound selected from the group consisting of thermosetting resins. The raw material organic compound may be used after being dissolved in a low molecular organic solvent in order to adjust the viscosity at the time of mixing.

Moreover, as natural graphite and / or artificial graphite used as a raw material of nuclear graphite, natural graphite subjected to spheroidizing treatment is preferable.
As an alloy material used as the negative electrode active material, as long as lithium can be occluded / released, lithium alone, simple metals and alloys forming lithium alloys, or oxides, carbides, nitrides, silicides, sulfides thereof Any of compounds such as products or phosphides may be used and is not particularly limited. The single metal and alloy forming the lithium alloy are preferably materials containing group 13 and group 14 metal / metalloid elements (that is, excluding carbon), more preferably aluminum, silicon and tin single metals and An alloy or compound containing these atoms. These may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

<Physical properties of carbonaceous materials>
When using a carbonaceous material as a negative electrode active material, it is desirable to have the following physical properties.
(X-ray parameters)
The d value (interlayer distance) of the lattice plane (002 plane) obtained by X-ray diffraction by the Gakushin method of carbonaceous materials is usually 0.335 nm or more, usually 0.360 nm or less, and 0.350 n
m or less is preferable, and 0.345 nm or less is more preferable. The crystallite size (Lc) of the carbonaceous material determined by X-ray diffraction by the Gakushin method is preferably 1.0 nm or more,
In particular, the thickness is more preferably 1.5 nm or more.

(Volume-based average particle size)
The volume-based average particle diameter of the carbonaceous material is a volume-based average particle diameter (median diameter) obtained by a laser diffraction / scattering method, and is usually 1 μm or more, preferably 3 μm or more, more preferably 5 μm or more, and 7 μm. The above is particularly preferable, and is usually 100 μm or less, 50
μm or less is preferable, 40 μm or less is more preferable, 30 μm or less is more preferable, and 2 μm or less is preferable.
5 μm or less is particularly preferable.

If the volume-based average particle size is below the above range, the irreversible capacity may increase, leading to loss of initial battery capacity. On the other hand, when the above range is exceeded, when an electrode is produced by coating, an uneven coating surface tends to be formed, which may be undesirable in the battery production process.
The volume-based average particle size is measured by dispersing carbon powder in a 0.2% by weight aqueous solution (about 10 mL) of polyoxyethylene (20) sorbitan monolaurate, which is a surfactant, and laser diffraction / scattering particle size distribution. This is performed using a meter (for example, LA-700 manufactured by Horiba, Ltd.). The median diameter determined by the measurement is defined as the volume-based average particle diameter of the carbonaceous material of the present invention.

(Raman R value)
The Raman R value of the carbonaceous material is a value measured using a laser Raman spectrum method,
Usually 0.01 or more, preferably 0.03 or more, more preferably 0.1 or more, and usually 1.5 or less, preferably 1.2 or less, more preferably 1 or less, 0.5 or less Is particularly preferred.

When the Raman R value is below the above range, the crystallinity of the particle surface becomes too high, and there are cases where the number of sites where Li enters between layers decreases with charge / discharge. That is, charge acceptance may be reduced. In addition, when the negative electrode is densified by applying it to the current collector and then pressing it, the crystals are likely to be oriented in a direction parallel to the electrode plate, which may lead to a decrease in load characteristics.
On the other hand, if it exceeds the above range, the crystallinity of the particle surface is lowered, the reactivity with the non-aqueous electrolyte is increased, and the efficiency may be lowered and the gas generation may be increased.

The Raman spectrum is measured by using a Raman spectrometer (for example, a Raman spectrometer manufactured by JASCO Corporation) to drop the sample naturally into the measurement cell and filling the sample cell with argon ion laser light (or a semiconductor). While irradiating a laser beam, the cell is rotated in a plane perpendicular to the laser beam. About the obtained Raman spectrum, 1580cm
The intensity IA of the peak PA near ⁻¹ and the intensity IB of the peak PB near 1360 cm ⁻¹ are measured, and the intensity ratio R (R = IB / IA) is calculated. The Raman R value calculated by the measurement is defined as the Raman R value of the carbonaceous material of the present invention.

Moreover, said Raman measurement conditions are as follows.
・ Laser wavelength: Ar ion laser 514.5 nm (semiconductor laser 532 nm)
Measurement range: 1100 cm ^{−1 to} 1730 cm ⁻¹
-Raman R value: background processing,
-Smoothing treatment: Simple average, 5 points of convolution (BET specific surface area)

BET specific surface area of the carbonaceous material is a value of the measured specific surface area using the BET method is usually 0.1 m ² · ^{g -1} or more, 0.7 m ² · ^{g -1} or more, 1. 0m ²・ g ^−
1 or more is more preferable, 1.5 m ² · g ⁻¹ or more is particularly preferable, and usually 100 m.
And a ² · ^{g -1} or less, preferably ^{25 m} 2 · ^{g -1} or less, ^{15 m} 2 · ^{g -1} and more preferably less, ^{10 m} 2 · ^{g -1} or less are especially preferred.

When the value of the BET specific surface area is less than this range, the acceptability of lithium is likely to deteriorate during charging when used as a negative electrode material, lithium is likely to precipitate on the electrode surface, and stability may be reduced. On the other hand, if it exceeds this range, when used as a negative electrode material, the reactivity with the non-aqueous electrolyte increases, gas generation tends to increase, and a preferable battery may be difficult to obtain.
The specific surface area is measured by the BET method using a surface area meter (for example, a fully automated surface area measuring device manufactured by Okura Riken), preliminarily drying the sample at 350 ° C. for 15 minutes under nitrogen flow, Using a nitrogen helium mixed gas that is accurately adjusted so that the relative pressure value of nitrogen is 0.3, the nitrogen adsorption BET one-point method is performed by a gas flow method.

(Roundness)
When the circularity is measured as the degree of the sphere of the carbonaceous material, it is preferably within the following range. The circularity is “circularity = (peripheral length of an equivalent circle having the same area as the particle projection shape) /
(Actual perimeter of the projected particle shape) ”, and when the circularity is 1, a theoretical sphere is obtained.
The degree of circularity of particles having a carbonaceous material particle size in the range of 3 to 40 μm is preferably closer to 1,
Moreover, 0.1 or more is preferable, and 0.5 or more is preferable, 0.8 or more is more preferable, 0.85 or more is further more preferable, and 0.9 or more is particularly preferable. High current density charge / discharge characteristics improve as the degree of circularity increases. Therefore, when the circularity is less than the above range, the filling property of the negative electrode active material is lowered, the resistance between particles is increased, and the high current density charge / discharge characteristics may be lowered for a short time.

The circularity is measured using a flow type particle image analyzer (for example, FPIA manufactured by Sysmex Corporation). About 0.2 g of a sample was dispersed in a 0.2% by mass aqueous solution (about 50 mL) of polyoxyethylene (20) sorbitan monolaurate as a surfactant, and irradiated with 28 kHz ultrasonic waves at an output of 60 W for 1 minute. The detection range is specified as 0.6 to 400 μm, and the particle size is 3 to 4
Measure for particles in the 0 μm range.

The method for improving the circularity is not particularly limited, but a sphere-shaped sphere is preferable because the shape of the interparticle void when the electrode body is formed is preferable. Examples of spheroidizing treatment include a method of mechanically approaching a sphere by applying a shearing force and a compressive force, a mechanical / physical processing method of granulating a plurality of fine particles by the binder or the adhesive force of the particles themselves, etc. Is mentioned.

(Tap density)
The tap density of the carbonaceous material is usually 0.1 g · cm ⁻³ or more, and 0.5 g · cm ^−3.
The above is preferable, 0.7 g · cm ⁻³ or more is more preferable, 1 g · cm ⁻³ or more is particularly preferable, 2 g · cm ⁻³ or less is preferable, 1.8 g · cm ⁻³ or less is more preferable, 1 It is particularly preferably not more than 0.6 g · cm ⁻³ . When the tap density is below the above range, the packing density is difficult to increase when used as a negative electrode, and a high-capacity battery may not be obtained. On the other hand, when the above range is exceeded, there are too few voids between particles in the electrode, it is difficult to ensure conductivity between the particles, and it may be difficult to obtain preferable battery characteristics.
The tap density is measured by passing through a sieve having an opening of 300 μm, dropping the sample onto a 20 cm ³ tapping cell and filling the sample to the upper end surface of the cell, and then measuring a powder density measuring device (for example, manufactured by Seishin Enterprise Co., Ltd.). Tap tapping with a stroke length of 10 mm
This is performed 0 times, and the tap density is calculated from the volume at that time and the mass of the sample.

(Orientation ratio)
The orientation ratio of the carbonaceous material is usually 0.005 or more, preferably 0.01 or more,
It is more preferably 15 or more, and usually 0.67 or less. When the orientation ratio is below the above range, the high-density charge / discharge characteristics may deteriorate. The upper limit of the above range is the theoretical upper limit value of the orientation ratio of the carbonaceous material.

The orientation ratio is measured by X-ray diffraction after pressure-molding the sample. 0.47 g of sample diameter 1
X-ray diffraction is measured by setting a molded body obtained by filling a molding machine of 7 mm and compressing at 58.8 MN · m ^{-2 so} that it is flush with the surface of the measurement sample holder. . From the (110) diffraction and (004) diffraction peak intensities of the obtained carbon, (110) diffraction peak intensity / (
004) Calculate the ratio represented by the diffraction peak intensity.

The X-ray diffraction measurement conditions are as follows. “2θ” indicates a diffraction angle.
・ Target: Cu (Kα ray) graphite monochromator ・ Slit:
Divergence slit = 0.5 degree Light receiving slit = 0.15 mm
Scattering slit = 0.5 degree / measurement range and step angle / measurement time:
(110) face: 75 degrees ≦ 2θ ≦ 80 degrees 1 degree / 60 seconds (004) face: 52 degrees ≦ 2θ ≦ 57 degrees 1 degree / 60 seconds (aspect ratio (powder))
The aspect ratio of the carbonaceous material is usually 1 or more and usually 10 or less, preferably 8 or less, and more preferably 5 or less. If the aspect ratio exceeds the above range, streaking or a uniform coated surface cannot be obtained when forming an electrode plate, and the high current density charge / discharge characteristics may deteriorate. In addition,
The lower limit of the above range is the theoretical lower limit value of the aspect ratio of the carbonaceous material.

The aspect ratio is measured by magnifying and observing the carbonaceous material particles with a scanning electron microscope. Carbonaceous material particles when three-dimensional observation is performed by selecting arbitrary 50 graphite particles fixed to the end face of a metal having a thickness of 50 μm or less and rotating and tilting the stage on which the sample is fixed. The longest diameter A and the shortest diameter B orthogonal thereto are measured, and the average value of A / B is obtained.

(Coverage)
The negative electrode active material of the present invention may be coated with a carbonaceous material or a graphite material. Among these, it is preferable that it is coated with an amorphous carbonaceous material from the viewpoint of lithium ion acceptability, and this coverage is usually 0.5% to 30%, preferably 1% to 25%, more preferably. Is 2% or more and 20% or less. If this content is too high, the amorphous carbon portion of the negative electrode active material increases, and the reversible capacity when the battery is assembled tends to be small. If the content is too small,
The amorphous carbon sites are not uniformly coated on the core graphite particles and strong granulation is not performed, and when pulverized after firing, the particle size tends to be too small.

In addition, the content rate (coverage) of the carbide derived from the organic compound of the negative electrode active material finally obtained is
The amount of the negative electrode active material, the amount of the organic compound, and the residual carbon ratio measured by a micro method based on JIS K 2270 can be calculated by the following formula.
Formula: coverage of carbide derived from organic compound (%) = (mass of organic compound × residual carbon ratio × 100)
/ {Mass of negative electrode active material + (mass of organic compound x residual carbon ratio)}

(Internal porosity)
The internal porosity of the negative electrode active material is usually 1% or more, preferably 3% or more, more preferably 5% or more, and further preferably 7% or more. Further, it is usually less than 50%, preferably 40% or less, more preferably 30% or less, and still more preferably 20% or less. If this internal porosity is too small, the amount of liquid in the particles tends to be small, and charge / discharge characteristics tend to deteriorate. Tend to be insufficient. In addition, the voids are filled with substances that buffer the expansion and contraction of metal particles that can be alloyed with Li, such as amorphous carbon, graphite, and resin. It may be.

<Metal particles that can be alloyed with Li>
As a method for confirming that the metal particles are metal particles that can be alloyed with Li,
Examples include identification of a metal particle phase by X-ray diffraction, observation and elemental analysis of a particle structure by an electron microscope, and elemental analysis by fluorescent X-rays.
Any conventionally known metal particles that can be alloyed with Li can be used, but from the viewpoint of capacity and cycle life, the metal particles may be, for example, Fe, Co, Sb, Bi, Pb, Ni, A
g, Si, Sn, Al, Zr, Cr, P, S, V, Mn, Nb, Mo, Cu, Zn, Ge
A metal selected from the group consisting of In, Ti and the like or a compound thereof is preferable. Further, an alloy composed of two or more kinds of metals may be used, and the metal particles may be alloy particles formed of two or more kinds of metal elements. Among these, a metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn, and W or a compound thereof is preferable.

Examples of the metal compound include a metal oxide, a metal nitride, and a metal carbide. Moreover, you may use the alloy which consists of 2 or more types of metals.
Among these, Si or Si compound is preferable in terms of increasing capacity. In this specification, Si or Si compounds are collectively referred to as Si compounds. As the Si compound, specifically, SiOx
, SiNx, SiCx, SiZxOy (Z = C, N), and the like, preferably SiOx when expressed by a general formula. This general formula SiOx is composed of Si dioxide (SiO ₂ ) and metallic Si.
(Si) is obtained as a raw material, and the value of x is usually 0 ≦ x <2. SiOx is
Compared with graphite, the theoretical capacity is large, and amorphous Si or nano-sized Si crystals are easy for alkali ions such as lithium ions to enter and exit, so that a high capacity can be obtained.

Specifically, it is expressed as SiOx, and x is 0 ≦ x <2, more preferably 0.2 or more and 1.8 or less, and further preferably 0.4 or more and 1.6 or less. Hereinafter, it is particularly preferably 0.6 or more and 1,4 or less, and X = 0 is particularly preferable. If it is this range, it becomes high capacity | capacitance and it becomes possible to reduce the irreversible capacity | capacitance by the coupling | bonding of Li and oxygen.

-Average particle diameter of metal particles that can be alloyed with Li (d50)
The average particle diameter (d50) of the metal particles that can be alloyed with Li is usually 0.01 μm or more, preferably 0.05 μm or more, more preferably 0.1 μm or more, and further preferably 0.3 μm, from the viewpoint of cycle life. This is usually 10 μm or less, preferably 9 μm or less, more preferably 8 μm or less. When the average particle diameter (d50) is within the above range, volume expansion associated with charge / discharge is reduced, and good cycle characteristics can be obtained while maintaining charge / discharge capacity.

The average particle diameter (d50) is determined by a laser diffraction / scattering particle size distribution measuring method or the like.
BET specific surface area of metal particles that can be alloyed with Li The specific surface area is usually 0.5 to 60 m ² / g by the BET method of metal particles that can be alloyed with Li,
It is preferable that it is 1-40 m < ² > / g. It is preferable that the specific surface area by the BET method of the metal particles that can be alloyed with Li is in the above-mentioned range since the charge / discharge efficiency and discharge capacity of the battery are high, lithium can be taken in and out quickly during high-speed charge / discharge, and the rate characteristics are excellent.

-The amount of oxygen contained in the metal particles that can be alloyed with Li The amount of oxygen contained in the metal particles that can be alloyed with Li is not particularly limited, but is usually 0.01-8 mass%, 0.05-5 mass% Preferably there is. The oxygen distribution state in the particle may exist near the surface, may exist inside the particle, or may exist uniformly within the particle, but is preferably present near the surface. It is preferable that the amount of oxygen contained in the metal particles that can be alloyed with Li is in the above-mentioned range because volume expansion associated with charge / discharge is suppressed due to strong bonding between Si and O, and cycle characteristics are excellent.

The negative electrode active material containing metal particles that can be alloyed with Li and graphite particles in the present invention is Li
It may be a mixture in which metal particles that can be alloyed and graphite particles are mixed in the form of particles independent of each other, or a composite in which metal particles that can be alloyed with Li are present on or inside the graphite particles. Good. In the present specification, the composite (also referred to as composite particle) is not particularly limited as long as it is a particle containing metal particles and carbonaceous materials that can be alloyed with Li, but preferably Li and an alloy. Metal particles and carbonaceous materials that can be converted into particles are integrated by physical and / or chemical bonds. As a more preferable form, the solid particles are dispersed and present in the particles so that the metal particles and carbonaceous materials that can be alloyed with Li are present at least on the composite particle surface and in the bulk. In order to integrate them by physical and / or chemical bonding, the carbonaceous material is present. More specifically, a preferable form is a composite material composed of at least metal particles capable of being alloyed with Li and graphite particles, and the graphite particles, preferably, natural graphite has a folded structure with a curved structure. Further, the negative electrode active material is characterized in that metal particles that can be alloyed with Li are present in the gaps in the folded structure having the curved surface. Further, the gap may be a gap, or a substance that buffers expansion and contraction of metal particles that can be alloyed with Li, such as amorphous carbon, graphite, and resin, is present in the gap. Also good.

-Content ratio of metal particles that can be alloyed with Li The content ratio of metal particles that can be alloyed with Li with respect to the sum of metal particles that can be alloyed with Li and graphite particles is usually 0.1 mass% or more, preferably 1 More preferably, it is 2 mass% or more, More preferably, it is 3 mass% or more, Most preferably, it is 5 mass% or more. Further, it is usually 99% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less, further preferably 30% by mass or less, still more preferably 25% by mass or less, particularly preferably 15% or less, and most preferably. It is 10 mass% or less. This range is preferable in that a sufficient capacity can be obtained.

The alloy-based material negative electrode can be produced using any known method. Specifically, as a manufacturing method of the negative electrode, for example, a method in which a negative electrode active material added with a binder or a conductive material is roll-formed as it is to form a sheet electrode, or a compression-molded pellet electrode and The above negative electrode is usually applied to a negative electrode current collector (hereinafter also referred to as “negative electrode current collector”) by a method such as a coating method, a vapor deposition method, a sputtering method, or a plating method. A method of forming a thin film layer (negative electrode active material layer) containing an active material is used. In this case, by adding a binder, a thickener, a conductive material, a solvent, etc. to the above-mentioned negative electrode active material to form a slurry, applying this to the negative electrode current collector, drying, and pressing to increase the density A negative electrode active material layer is formed on the negative electrode current collector.

Examples of the material of the negative electrode current collector include steel, copper alloy, nickel, nickel alloy, and stainless steel. Of these, copper foil is preferred from the viewpoint of easy processing into a thin film and cost.
The thickness of the negative electrode current collector is usually 1 μm or more, preferably 5 μm or more, and usually 100 μm.
Hereinafter, it is preferably 50 μm or less. If the thickness of the negative electrode current collector is too thick, the capacity of the entire battery may be too low, and conversely, if it is too thin, handling may be difficult.

In addition, in order to improve the binding effect with the negative electrode active material layer formed on the surface, the surface of these negative electrode current collectors is preferably subjected to a roughening treatment in advance. Surface roughening methods include blasting, rolling with a rough roll, abrasive cloth paper with abrasive particles fixed, grindstone, emery buff,
Examples thereof include a mechanical polishing method, an electrolytic polishing method, a chemical polishing method, and the like for polishing the surface of the current collector with a wire brush provided with a steel wire or the like.

Further, in order to reduce the mass of the negative electrode current collector and improve the energy density per mass of the battery, a perforated negative electrode current collector such as an expanded metal or a punching metal can be used. In this type of negative electrode current collector, the mass can be changed to white by changing the aperture ratio. Further, when a negative electrode active material layer is formed on both surfaces of this type of negative electrode current collector, the negative electrode active material layer is further less likely to peel due to the rivet effect through the hole. However, when the aperture ratio becomes too high, the contact area between the negative electrode active material layer and the negative electrode current collector becomes small, and thus the adhesive strength may be lowered.

The slurry for forming the negative electrode active material layer is usually prepared by adding a binder, a thickener and the like to the negative electrode material. In addition, the “negative electrode material” in this specification refers to a material in which a negative electrode active material and a conductive material are combined.
The content of the negative electrode active material in the negative electrode material is usually 70% by mass or more, particularly 75% by mass or more,
Further, it is usually 97% by mass or less, particularly preferably 95% by mass or less. If the content of the negative electrode active material is too small, the capacity of the secondary battery using the obtained negative electrode tends to be insufficient. It tends to be difficult to ensure conductivity. When two or more negative electrode active materials are used in combination, the total amount of the negative electrode active materials may be set to satisfy the above range.

Examples of the conductive material used for the negative electrode include metal materials such as copper and nickel; carbon materials such as graphite and carbon black. These may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio. In particular, it is preferable to use a carbon material as the conductive material because the carbon material acts as an active material. The content of the conductive material in the negative electrode material is usually 3% by mass or more, particularly 5% by mass or more, and usually 30% by mass or less, and particularly preferably 25% by mass or less. When the content of the conductive material is too small, the conductivity tends to be insufficient. When the content is too large, the content of the negative electrode active material and the like is relatively insufficient, and thus the battery capacity and strength tend to decrease. Note that when two or more conductive materials are used in combination, the total amount of the conductive materials may satisfy the above range.

As the binder used for the negative electrode, any material can be used as long as it is a material safe with respect to the solvent and the electrolytic solution used at the time of producing the electrode. Examples thereof include polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, styrene / butadiene rubber / isoprene rubber, butadiene rubber, ethylene / acrylic acid copolymer, and ethylene / methacrylic acid copolymer. These may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio. It is preferable that the content of the binder is usually 0.5 parts by mass or more, particularly 1 part by mass or more, and usually 10 parts by mass or less, particularly 8 parts by mass or less with respect to 100 parts by mass of the negative electrode material. When the content of the binder is too small, the strength of the obtained negative electrode tends to be insufficient, and when the content is too large, the content of the negative electrode active material and the like is relatively insufficient, and thus the battery capacity and conductivity are insufficient It becomes. In addition, when using two or more binders together, what is necessary is just to make it the total amount of a binder satisfy | fill the said range.

As the thickener used for the negative electrode, carboxymethylcellulose, methylcellulose,
Examples thereof include hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, and casein. One of these may be used alone, or 2
You may use a seed or more together by arbitrary combinations and ratios. The thickener may be used as necessary, but when used, the content of the thickener in the negative electrode active material layer is usually 0.5% by mass.
It is preferably used in the range of 5% by mass or less.

The slurry for forming the negative electrode active material layer is prepared by mixing a conductive agent, a binder, and a thickener as necessary with the negative electrode active material, and using an aqueous solvent or an organic solvent as a dispersion medium. The As the aqueous solvent, water is usually used, and an organic solvent such as alcohols such as ethanol and cyclic amides such as N-methylpyrrolidone is used in combination within a range of 30% by mass or less with respect to water. You can also. As the organic solvent, usually, cyclic amides such as N-methylpyrrolidone, linear amides such as N, N-dimethylformamide and N, N-dimethylacetamide, and aromatic carbonization such as anisole, toluene and xylene Examples thereof include alcohols such as hydrogens, butanol and cyclohexanol, among which cyclic amides such as N-methylpyrrolidone, linear amides such as N, N-dimethylformamide and N, N-dimethylacetamide are preferable. . Any one of these may be used alone, or two or more may be used in any combination and ratio.
The obtained slurry is applied onto the above-described negative electrode current collector, dried, and then pressed to form a negative electrode active material layer. The method of application is not particularly limited, and a method known per se can be used. The drying method is not particularly limited, and a known method such as natural drying, heat drying, or reduced pressure drying can be used.

<Configuration and production method of negative electrode>
Any known method can be used for producing the electrode as long as the effects of the present invention are not significantly impaired. For example, it is formed by adding a binder, a solvent, and, if necessary, a thickener, a conductive material, a filler, etc. to a negative electrode active material to form a slurry, which is applied to a current collector, dried and then pressed. Can do.
In addition, when using an alloy-based material, by techniques such as vapor deposition, sputtering, plating,
A method of forming a thin film layer (negative electrode active material layer) containing the above-described negative electrode active material is also used.

(Electrode density)
The electrode structure when the negative electrode active material is made into an electrode is not particularly limited, but the density of the negative electrode active material present on the current collector is preferably 1 g · cm ⁻³ or more, and 1.2 g · cm ⁻³ or more. but more preferably, particularly preferably 1.3 g · ^{cm -3} or more, preferably 2.2 g · ^{cm -3} or less, more preferably 2.1 g · ^{cm -3} or less, 2.0 g · ^{cm -3} or less Further preferred is 1.9 g · cm ⁻³ or less. When the density of the negative electrode active material existing on the current collector exceeds the above range, the negative electrode active material particles are destroyed, and the initial irreversible capacity increases or non-aqueous system near the current collector / negative electrode active material interface. There is a case where high current density charge / discharge characteristics are deteriorated due to a decrease in permeability of the electrolytic solution. On the other hand, if the amount is less than the above range, the conductivity between the negative electrode active materials decreases, the battery resistance increases, and the capacity per unit volume may decrease.

2-2. Positive electrode <Positive electrode active material>
The positive electrode active material (lithium transition metal compound) used for the positive electrode is described below.
<Lithium transition metal compound>
A lithium transition metal compound is a compound having a structure capable of desorbing and inserting Li ions, and examples thereof include sulfides, phosphate compounds, and lithium transition metal composite oxides. Sulfides include compounds having a two-dimensional layered structure such as TiS ₂ and MoS ₂ , and strong tertiary compounds represented by the general formula MexMo ₆ S ₈ (Me is various transition metals including Pb, Ag, and Cu). Examples thereof include a chevrel compound having an original skeleton structure. Examples of the phosphate compound include those belonging to the olivine structure, and are generally represented by LiMePO ₄ (Me is at least one or more transition metals), specifically, LiFePO ₄ , LiCoPO _4.
, LiNiPO ₄ , LiMnPO _{4 and the} like. Examples of the lithium transition metal composite oxide include spinel structures capable of three-dimensional diffusion and those belonging to a layered structure capable of two-dimensional diffusion of lithium ions. Those having a spinel structure are generally LiMe.
₂ O ₄ (Me is at least one or more transition metals), specifically LiMn ₂ O ₄ ,
Examples include LiCoMnO ₄ , LiNi _0.5 Mn _1.5 O ₄ , and LiCoVO ₄ .
Those having a layered structure are generally expressed as LiMeO ₂ (Me is at least one transition metal). Specifically, LiCoO ₂ , LiNiO ₂ , LiNi _1-x Co _x O ₂ , L
iNi _1-xy Co _x Mn _y O ₂ , LiNi _0.5 Mn _0.5 O ₂ , Li _1.2 Cr _{0
. 4 Mn 0.4 O 2, Li 1.2} Cr 0.4 Ti 0.4 O 2, such as LiMnO ₂ and the like.

<composition>
The lithium-containing transition metal compound is, for example, a lithium transition metal compound represented by the following composition formula (A) or (B).
1) In the case of a lithium transition metal compound represented by the following composition formula (A)
Li _{1 + x} MO ₂ (A)
However, x is usually 0 or more and 0.5 or less. M is Ni and Mn, or Ni, M
It is an element composed of n and Co, and the Mn / Ni molar ratio is usually 0.1 or more and 5 or less. The Ni / M molar ratio is usually 0 or more and 0.5 or less. Co / M molar ratio is usually 0 or more, 0
. 5 or less. In addition, the rich portion of Li represented by x may be replaced with the transition metal site M.

In the composition formula (A), the atomic ratio of the oxygen amount is described as 2 for convenience, but there may be some non-stoichiometry. Moreover, x in the said compositional formula is the preparation composition in the manufacture stage of a lithium transition metal type compound. Usually, batteries on the market are aged after the batteries are assembled. For this reason, the Li amount of the positive electrode may be deficient with charge / discharge. In this case, x may be measured to be −0.65 or more and 1 or less when discharged to 3 V in composition analysis.

A lithium transition metal-based compound is excellent in battery characteristics when fired at a high temperature in an oxygen-containing gas atmosphere in order to enhance the crystallinity of the positive electrode active material.
Further, the lithium transition metal-based compound represented by the composition formula (A) may be a solid solution with Li ₂ MO ₃ called a 213 layer, as shown in the general formula (A ′) below.
αLi ₂ MO ₃ · (1-α) LiM′O ₂ (A ′)
In the general formula, α is a number satisfying 0 <α <1.

M is at least one metal element having an average oxidation number of 4+, specifically, Mn,
It is at least one metal element selected from the group consisting of Zr, Ti, Ru, Re and Pt.
M ′ is at least one metal element having an average oxidation number of 3+, preferably V,
At least one metal element selected from the group consisting of Mn, Fe, Co and Ni;
More preferably, it is at least one metal element selected from the group consisting of Mn, Co and Ni.

2) A lithium transition metal compound represented by the following general formula (B).
_{Li [Li a M b Mn 2} -b-a] O 4 + δ ··· (B)
However, M is an element comprised from at least 1 sort (s) of the transition metals chosen from Ni, Cr, Fe, Co, Cu, Zr, Al, and Mg.
The value of b is usually 0.4 or more and 0.6 or less.
If the value of b is this range, the energy density per unit mass in a lithium transition metal type compound will be high.

The value of a is usually 0 or more and 0.3 or less. Further, a in the composition formula is a charged composition at the production stage of the lithium transition metal compound. Usually, batteries on the market are aged after the batteries are assembled. For this reason, the Li amount of the positive electrode may be deficient with charge / discharge. In that case, a in the case of discharging to 3 V is −0.65 in composition analysis.
As mentioned above, it may be measured to 1 or less.

When the value of a is within this range, the energy density per unit mass in the lithium transition metal compound is not significantly impaired, and good load characteristics can be obtained.
Furthermore, the value of δ is usually in the range of ± 0.5.
If the value of δ is within this range, the stability as a crystal structure is high, and the cycle characteristics and high-temperature storage of a battery having an electrode produced using this lithium transition metal compound are good.

Here, the chemical meaning of the lithium composition in the lithium nickel manganese composite oxide, which is the composition of the lithium transition metal compound, will be described in more detail below.
In order to obtain a and b in the composition formula of the lithium transition metal compound, each transition metal and lithium are analyzed by an inductively coupled plasma emission spectrometer (ICP-AES), and Li / Ni / Mn
It is calculated by calculating the ratio of.

From a structural point of view, it is considered that lithium related to a is substituted for the same transition metal site. Here, due to the lithium according to a, the average valence of M and manganese becomes larger than 3.5 due to the principle of charge neutrality.
The lithium transition metal compound may be fluorine-substituted, and LiMn ₂ O
It is written _4-x F _2x .

<blend>
Specific examples of the lithium transition metal compound having the above composition include, for example, Li _{1 + x} Ni _{0
. 5} Mn _0.5 O ₂ , Li _{1 + x} Ni _0.85 Co _0.10 Al _0.05 O ₂ , Li _{1+
x Ni 0.33 Mn 0.33 Co 0.33 O} 2, Li 1 + x Ni 0.45 Mn 0.45 C
o _0.1 O ₂ , Li _{1 + x} Mn _1.8 Al _0.2 O ₄ , Li _{1 + x} Mn _1.5 Ni _0.5
O ₄ etc. are mentioned. These lithium transition metal compounds may be used alone or in a blend of two or more.

<Introduction of foreign elements>
Moreover, a different element may be introduce | transduced into a lithium transition metal type compound. As a foreign element, B
, Na, Mg, Al, K, Ca, Ti, V, Cr, Fe, Cu, Zn, Sr, Y, Zr,
Nb, Ru, Rh, Pd, Ag, In, Sb, Te, Ba, Ta, Mo, W, Re, Os
, Ir, Pt, Au, Pb, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy,
Ho, Er, Tm, Yb, Lu, Bi, N, F, S, Cl, Br, I, As, Ge, P,
It is selected from any one or more of Pb, Sb, Si and Sn. These foreign elements are
It may be incorporated into the crystal structure of the lithium transition metal compound, or may not be incorporated into the crystal structure of the lithium transition metal compound, and may be unevenly distributed as a single substance or compound on the particle surface or grain boundary. Good.

[Positive electrode for lithium secondary battery]
The positive electrode for a lithium secondary battery is formed by forming a positive electrode active material layer containing the above-described lithium transition metal compound powder for a lithium secondary battery positive electrode material and a binder on a current collector.
The positive electrode active material layer is usually formed by mixing a positive electrode material, a binder, and a conductive material and a thickener, which are used if necessary, in a dry form into a sheet shape, and then pressing the positive electrode current collector on the positive electrode current collector. Alternatively, these materials are dissolved or dispersed in a liquid medium to form a slurry, which is applied to the positive electrode current collector and dried.

As the material for the positive electrode current collector, metal materials such as aluminum, stainless steel, nickel plating, titanium, and tantalum, and carbon materials such as carbon cloth and carbon paper are usually used. As for the shape, in the case of a metal material, a metal foil, a metal cylinder, a metal coil, a metal plate, a metal thin film, an expanded metal, a punch metal, a foam metal, etc. Etc. In addition, you may form a thin film suitably in mesh shape.
When a thin film is used as the positive electrode current collector, its thickness is arbitrary, but usually 1 μm or more, 1
A range of 00 mm or less is preferred. If it is thinner than the above range, the strength required for the current collector may be insufficient. On the other hand, if it is thicker than the above range, the handleability may be impaired.

The binder used in the production of the positive electrode active material layer is not particularly limited, and in the case of a coating method, any material that is stable with respect to the liquid medium used during electrode production may be used. Specific examples include polyethylene, Resin polymers such as polypropylene, polyethylene terephthalate, polymethyl methacrylate, aromatic polyamide, cellulose, nitrocellulose, SBR (styrene butadiene rubber), NBR (acrylonitrile butadiene rubber), fluorine rubber, isoprene rubber, butadiene rubber, ethylene・ Rubber polymers such as propylene rubber, styrene / butadiene / styrene block copolymers and hydrogenated products thereof, EPDM (ethylene / propylene / diene terpolymers), styrene / ethylene / butadiene / ethylene copolymers, Styrene / isoprene styrene bromide Copolymer and its hydrogenated thermoplastic elastomeric polymer, syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene / vinyl acetate copolymer, propylene / α-olefin copolymer, etc. Fluorine polymers such as soft resinous polymers, polyvinylidene fluoride, polytetrafluoroethylene, fluorinated polyvinylidene fluoride, polytetrafluoroethylene / ethylene copolymers, ion conductivity of alkali metal ions (especially lithium ions) And a polymer composition having the same. In addition, these substances may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

The ratio of the binder in the positive electrode active material layer is usually 0.1% by mass or more and 80% by mass or less. If the proportion of the binder is too low, the positive electrode active material cannot be sufficiently retained and the positive electrode has insufficient mechanical strength, which may deteriorate battery performance such as cycle characteristics. Battery capacity and conductivity may be reduced.
The positive electrode active material layer usually contains a conductive material in order to increase conductivity. There are no particular restrictions on the type, but specific examples include metal materials such as copper and nickel, graphite such as natural graphite and artificial graphite, carbon black such as acetylene black, and amorphous carbon such as needle coke. And carbon materials. In addition, these substances may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios. The proportion of the conductive material in the positive electrode active material layer is usually 0.01% by mass or more and 50% by mass or less. If the proportion of the conductive material is too low, the conductivity may be insufficient, and conversely if it is too high, the battery capacity may be reduced.

As a liquid medium for forming a slurry, it is possible to dissolve or disperse a lithium transition metal compound powder as a positive electrode material, a binder, and a conductive material and a thickener used as necessary. If it is a solvent, there is no restriction | limiting in particular in the kind, You may use either an aqueous solvent or an organic solvent. Examples of the aqueous solvent include water and alcohol. Examples of the organic solvent include N-methylpyrrolidone (NMP), dimethylformamide, dimethylacetamide, methyl ethyl ketone, cyclohexanone, methyl acetate, methyl acrylate, diethyltriamine, N , N-dimethylaminopropylamine, ethylene oxide, tetrahydrofuran (THF), toluene, acetone, dimethyl ether, dimethylacetamide, hexamethylphosphalamide, dimethyl sulfoxide, benzene, xylene, quinoline, pyridine, methylnaphthalene, hexane, etc. be able to. In particular, when an aqueous solvent is used, a dispersant is added together with the thickener, and a slurry such as SBR is slurried. In addition,
These solvents may be used alone or in combination of two or more in any combination and ratio.

The content ratio of the lithium transition metal-based compound powder as the positive electrode material in the positive electrode active material layer is usually 10% by mass or more and 99.9% by mass or less. If the proportion of the lithium transition metal compound powder in the positive electrode active material layer is too large, the strength of the positive electrode tends to be insufficient, and if it is too small, the capacity may be insufficient.
The thickness of the positive electrode active material layer is usually about 10 to 200 μm.

The electrode density after pressing the positive electrode is usually 2.2 g / cm ³ or more and 4.2 g / cm ^3.
It is as follows.
The positive electrode active material layer obtained by coating and drying is preferably consolidated by a roller press or the like in order to increase the packing density of the positive electrode active material.
Thus, a positive electrode for a lithium secondary battery can be prepared.

2-3. Separator Normally, a separator is interposed between the positive electrode and the negative electrode in order to prevent a short circuit. In this case, the nonaqueous electrolytic solution of the present invention is usually used by impregnating the separator.
The material and shape of the separator are not particularly limited, and known ones can be arbitrarily adopted as long as the effects of the present invention are not significantly impaired. Among them, a resin, glass fiber, inorganic material, etc. formed of a material that is stable with respect to the non-aqueous electrolyte solution of the present invention is used, and a porous sheet or a nonwoven fabric-like material having excellent liquid retention properties is used. Is preferred.

As materials for the resin and glass fiber separator, for example, polyolefins such as polyethylene and polypropylene, aromatic polyamides, polytetrafluoroethylene, polyethersulfone, glass filters and the like can be used. Of these, glass filters and polyolefins are preferred, and polyolefins are more preferred. These materials may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

The thickness of the separator is arbitrary, but is usually 1 μm or more, preferably 5 μm or more.
It is more preferably 0 μm or more, usually 50 μm or less, preferably 40 μm or less, more preferably 30 μm or less. If the separator is too thin than the above range, the insulating properties and mechanical strength may decrease. On the other hand, if it is thicker than the above range, not only the battery performance such as the rate characteristic may be lowered, but also the energy density of the whole non-aqueous electrolyte secondary battery may be lowered.

Furthermore, when a porous material such as a porous sheet or nonwoven fabric is used as the separator, the porosity of the separator is arbitrary, but is usually 20% or more, preferably 35% or more, and 45%
The above is more preferable, and it is usually 90% or less, preferably 85% or less, and more preferably 75% or less. If the porosity is too smaller than the above range, the membrane resistance tends to increase and the rate characteristics tend to deteriorate. Moreover, when larger than the said range, it exists in the tendency for the mechanical strength of a separator to fall and for insulation to fall.

The average pore diameter of the separator is also arbitrary, but is usually 0.5 μm or less and 0.2 μm.
The following is preferable and is usually 0.05 μm or more. If the average pore diameter exceeds the above range, a short circuit tends to occur. On the other hand, below the above range, the film resistance may increase and the rate characteristics may deteriorate.
On the other hand, as the inorganic material, for example, oxides such as alumina and silicon dioxide, nitrides such as aluminum nitride and silicon nitride, and sulfates such as barium sulfate and calcium sulfate are used. Used.

As the form, a thin film shape such as a non-woven fabric, a woven fabric, or a microporous film is used. In the thin film shape, those having a pore diameter of 0.01 to 1 μm and a thickness of 5 to 50 μm are preferably used.
In addition to the above-mentioned independent thin film shape, a separator formed by forming a composite porous layer containing inorganic particles on the surface layer of the positive electrode and / or the negative electrode using a resin binder can be used. For example, a porous layer may be formed by using alumina particles having a 90% particle size of less than 1 μm on both surfaces of the positive electrode and using a fluororesin as a binder.

The characteristics of the separator in the non-electrolyte secondary battery can be grasped by the Gurley value. The Gurley value indicates the difficulty of air passage in the film thickness direction, and is expressed as the number of seconds required for 100 ml of air to pass through the film. It means that it is harder to go through. That is, a smaller value means better communication in the thickness direction of the film, and a larger value means lower communication in the thickness direction of the film. Communication is the degree of connection of holes in the film thickness direction. If the Gurley value of the separator of the present invention is low, it can be used for various purposes. For example, when used as a separator for non-aqueous lithium secondary batteries, the Gurley value is low,
This means that lithium ions can be easily transferred, which is preferable because of excellent battery performance. Although the Gurley value of a separator is arbitrary, Preferably it is 10-1000 second / 100ml, More preferably, it is 15-800 second / 100ml, More preferably, it is 20-500 second /
100 ml. If the Gurley value is 1000 seconds / 100 ml or less, the electrical resistance is substantially low, which is preferable as a separator.

2-4. Battery design <Electrode group>
The electrode group has a laminated structure in which the positive electrode plate and the negative electrode plate are interposed via the separator,
Any of those having a structure in which the positive electrode plate and the negative electrode plate are wound in a spiral shape with the separator interposed therebetween may be used. The ratio of the volume of the electrode group to the internal volume of the battery (hereinafter referred to as electrode group occupancy) is usually 40% or more, preferably 50% or more, and usually 90% or less.
80% or less is preferable.

When the electrode group occupancy is below the above range, the battery capacity decreases. Also, if the above range is exceeded, the void space is small, the battery expands, and the member expands or the vapor pressure of the electrolyte liquid component increases and the internal pressure rises. In some cases, the gas release valve that lowers various characteristics such as storage at high temperature and the like, or releases the internal pressure to the outside is activated.

<Exterior case>
The material of the outer case is not particularly limited as long as it is a substance that is stable with respect to the non-aqueous electrolyte used. Specifically, a nickel-plated steel plate, stainless steel, aluminum, an aluminum alloy, a metal such as a magnesium alloy, or a laminated film (laminate film) of a resin and an aluminum foil is used. From the viewpoint of weight reduction, an aluminum or aluminum alloy metal or a laminate film is preferably used.

In an exterior case using metals, the metal is welded together by laser welding, resistance welding, or ultrasonic welding to form a sealed sealed structure, or a caulking structure using the above metals via a resin gasket. Things. Examples of the outer case using the laminate film include a case where a resin-sealed structure is formed by heat-sealing resin layers. In order to improve sealing performance, a resin different from the resin used for the laminate film may be interposed between the resin layers. In particular, when a resin layer is heat-sealed through a current collecting terminal to form a sealed structure, a metal and a resin are joined, so that a resin having a polar group or a modified group having a polar group introduced as an intervening resin is used. Resins are preferably used.

<Protective element>
As a protective element, PTC (Posit) increases in resistance when abnormal heat generation or excessive current flows
For example, a temperature fuse, a thermistor, a valve that cuts off a current flowing in the circuit due to a sudden rise in battery internal pressure or internal temperature during abnormal heat generation (current cutoff valve), or the like can be used. It is preferable to select a protective element that does not operate under normal use at a high current, and it is more preferable that the protective element is designed so as not to cause abnormal heat generation or thermal runaway even without the protective element.

(Exterior body)
The non-aqueous electrolyte secondary battery of the present invention is usually configured by housing the non-aqueous electrolyte, the negative electrode, the positive electrode, the separator, and the like in an exterior body (exterior case). There is no restriction | limiting in this exterior body, As long as the effect of this invention is not impaired remarkably, a well-known thing can be employ | adopted arbitrarily.
The material of the outer case is not particularly limited as long as it is a substance that is stable with respect to the non-aqueous electrolyte used. Specifically, a nickel-plated steel plate, stainless steel, aluminum or an aluminum alloy, a magnesium alloy, nickel, titanium, or a metal, or a laminated film (laminate film) of a resin and an aluminum foil is used. From the viewpoint of weight reduction, an aluminum or aluminum alloy metal or a laminate film is preferably used.

In the outer case using the above metals, the metal is welded to each other by laser welding, resistance welding, ultrasonic welding, or a sealed sealing structure, or a caulking structure using the above metals through a resin gasket To do. Examples of the outer case using the laminate film include a case where a resin-sealed structure is formed by heat-sealing resin layers. In order to improve sealing performance, a resin different from the resin used for the laminate film may be interposed between the resin layers. In particular, when a resin layer is heat-sealed through a current collecting terminal to form a sealed structure, a metal and a resin are joined, so that a resin having a polar group or a modified group having a polar group introduced as an intervening resin is used. Resins are preferably used.

The shape of the outer case is also arbitrary, and may be any of a cylindrical shape, a square shape, a laminate shape, a coin shape, a large size, and the like.
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples.
The compound containing the structure represented by the general formula (A) used in this example is shown below.

<Examples 1-1 to 1-2, 1-5 to 1-7, Comparative Examples 1-1 to 1-8>
[Preparation of non-aqueous electrolyte]
Under a dry argon atmosphere, a mixture of monofluoroethylene carbonate and ethylmethyl carbonate (EMC) (volume ratio 2: 8) was mixed with 1 mol / L of LiPF ₆ sufficiently dried (concentration in the non-aqueous electrolyte). ) (This is referred to as reference electrolyte 1). A compound was added to the entire reference electrolyte solution 1 at a ratio shown in Table 1 below to prepare an electrolyte solution. However, Comparative Example 1-1 is the reference electrolyte 1 itself.

[Production of positive electrode]
94% by mass of lithium cobaltate (LiCoO ₂ ) as a positive electrode active material, 3% by mass of acetylene black as a conductive material, and 3% by mass of polyvinylidene fluoride (PVdF) as a binder
Were mixed with a disperser in an N-methylpyrrolidone solvent to form a slurry. This was uniformly applied to both sides of a 21 μm thick aluminum foil, dried, and then pressed to obtain a positive electrode.

[Production of negative electrode]
As a negative electrode active material, silicon powder and graphite powder and a binder were mixed, and an N-methylpyrrolidone solution was added thereto, and mixed with a disperser to form a slurry. The obtained slurry was uniformly applied onto a 20 μm thick copper foil as a negative electrode current collector to form a negative electrode, and the negative electrode was cut out so that the active material had a width of 30 mm and a length of 40 mm. This negative electrode is 60 degrees Celsius.
And then dried under reduced pressure for 12 hours.

[Manufacture of non-aqueous electrolyte batteries (laminate type)]
The positive electrode, the negative electrode, and the polyolefin separator were laminated in the order of the negative electrode, the separator, and the positive electrode. The battery element thus obtained is wrapped in an aluminum laminate film,
After injecting an electrolyte solution to be described later, it was vacuum-sealed to produce a sheet-like non-aqueous electrolyte secondary battery.

<Evaluation of non-aqueous electrolyte secondary battery>
[High-temperature cycle test]
In a constant temperature bath at 25 ° C., a non-aqueous electrolyte secondary battery of a coin-type cell was charged at a constant current for 4 hours at a current corresponding to 0.05 C (hereinafter referred to as “CC charging” as appropriate), and then 4 at 0.2 C. Constant current-constant voltage charging (hereinafter referred to as “CC-CV charging” as appropriate) up to 0.0 V was performed. Then 0.2
C was discharged to 2.75V. Subsequently, after CC-CV to 4.0V at 0.2C, 0.2
C was discharged to 2.75 V to stabilize the non-aqueous electrolyte secondary battery. Then 4 at 0.2C
. After performing CC-CV charge up to 2V, the battery was discharged to 2.75V at 0.2C for initial conditioning.

The cell after initial conditioning is CCC up to 4.2V at 0.5C in a 45 ° C constant temperature bath.
The process of discharging to 2.75V at a constant current of 0.5C after charging V is taken as one cycle.
00 cycles were performed. The capacity at the 200th cycle was defined as “capacity after 200 cycles”. Here, 1C represents a current value for discharging the reference capacity of the battery in one hour, and for example, 0.2C represents a current value of 1/5 thereof.

  Table 1 below shows the capacity after 200 cycles normalized by the value of Comparative Example 1-1.

<Examples 2-1 to 2-3, Comparative Examples 2-1 to 2-4>
[Preparation of non-aqueous electrolyte]
Under a dry argon atmosphere, a mixture of the compound (g) and EMC in the proportions shown in Table 2 below,
The fully dried LiPF ₆ was dissolved at 1 mol / L (as a concentration in the non-aqueous electrolyte).
On the other hand, an electrolyte solution was prepared by adding a compound at a ratio shown in Table 2 below.

[Production of positive electrode]
97% by mass of lithium cobaltate (LiCoO ₂ ) as a positive electrode active material, 1.5% by mass of acetylene black as a conductive material, and polyvinylidene fluoride (PVdF) as a binder.
5% by mass was mixed with a disperser in an N-methylpyrrolidone solvent to form a slurry. This was uniformly applied to both sides of a 21 μm thick aluminum foil, dried, and then pressed to obtain a positive electrode.

[Production of negative electrode]
100 parts by weight of graphite powder as the negative electrode active material, 1 part by weight of aqueous dispersion of sodium carboxymethyl cellulose (concentration of 1% by weight of sodium carboxymethyl cellulose) as the thickener and binder, respectively, and aqueous dispersion of styrene-butadiene rubber 1 part by mass (concentration of styrene-butadiene rubber 50% by mass) was added and mixed with a disperser to form a slurry. This slurry was uniformly applied to one side of a 12 μm thick copper foil, dried, and then pressed to obtain a negative electrode.

[Manufacture of non-aqueous electrolyte batteries (coin type)]
Using the above positive electrode and negative electrode and the non-aqueous electrolyte prepared in each Example and Comparative Example, a coin-type cell was produced by the following procedure. That is, the negative electrode was placed through a polyethylene separator impregnated with an electrolytic solution on a positive electrode accommodated in a stainless steel can body also serving as a positive electrode conductor. The can body and a sealing plate serving also as a negative electrode conductor were caulked and sealed via an insulating gasket to produce a coin-type cell.

[Battery evaluation]
In a constant temperature bath at 25 ° C., a non-aqueous electrolyte secondary battery of a coin-type cell was charged with a constant current for 6 hours at a current corresponding to 0.05 C (hereinafter referred to as “CC charging” as appropriate), and then 3 at 0.2 C. The value obtained by discharging to 0.000 V and [discharge capacity] / [charge capacity] of the obtained capacity was defined as the initial efficiency. Constant current-constant voltage charge up to 4.1V at 0.2C (hereinafter referred to as "CC-CV charge" as appropriate)
Went. Then, it discharged to 3.00V at 0.2C, and stabilized the non-aqueous electrolyte secondary battery. Then, after performing CC-CV charge to 4.33V at 0.2C, 3.00 at 0.2C
The operation of discharging to V was performed three times, and the third discharge capacity was set to “0.2 C capacity”. here,
1C represents a current value that discharges the reference capacity of the battery in one hour. For example, 0.2C is 1
This represents a current value of / 5.

[High temperature storage characteristics evaluation]
The nonaqueous electrolyte battery after the initial capacity evaluation was performed at 25 ° C. and 0.2C at 4.33.
After performing CC-CV charging (0.05 C cut) to V, high temperature storage was performed at 85 ° C. for 24 hours. After sufficiently cooling the battery, the battery was discharged at 25 ° C. to 3 V at 0.2 C, and the capacity after the high temperature storage characteristic evaluation was determined. This was defined as “remaining capacity after high temperature storage”.
Table 2 below shows the initial efficiency, the 0.2 C capacity, and the remaining capacity after the high temperature storage test, normalized by the values of Comparative Example 2-1.

When Examples 2-1 to 2-3 and Comparative Example 2-1 were compared, the content of the compound (g) with respect to the electrolytic solution was 50% by mass or less, compared with Comparative Example 2-1 exceeding 50% by mass. It can be seen that the initial efficiency is improved. When attention is paid to Comparative Example 2-2, the characteristics do not reach those of Examples 2-1 to 2-3 unless the compound (g) is contained. Therefore, it is important to contain a specific amount of the compound (g) in the electrolytic solution. It can be seen that it is. Further, from Comparative Examples 2-2 and 2-3, the compound (a) and the compound (
Even if each of g) is used alone, both the initial efficiency and the initial capacity do not reach Example 2-1, and it can be seen that co-addition of the compound (a) and the compound (g) greatly improves the characteristics. The same can be said for the remaining capacity after the high-temperature storage test.

<Example 3-A-1 to 3-A-15, Comparative Example 3-A-1 to 3-A-5>
[Preparation of non-aqueous electrolyte]
In a dry argon atmosphere, 1 mol / L (as a concentration in a non-aqueous electrolyte) of LiPF ₆ sufficiently dried was dissolved in a mixture of ethylene carbonate and diethyl carbonate (DEC) (volume ratio 3: 7). Furthermore, 2.0% by mass of vinylene carbonate (VC) and fluoroethylene carbonate were added (this is referred to as reference electrolyte solution 3-A). A compound was added to the entire reference electrolyte solution 3 at a ratio shown in Table 3 below to prepare an electrolyte solution. However, Comparative Example 3-A-1 is the reference electrolytic solution 3-A itself.

[Production of positive electrode]
Lithium / nickel / cobalt / manganese composite oxide (NMC) 85 as positive electrode active material
A slurry was prepared by mixing 10% by mass of acetylene black as a conductive material and 5% by mass of polyvinylidene fluoride (PVdF) as a binder in a N-methylpyrrolidone solvent with a disperser. This was uniformly applied to both sides of a 21 μm thick aluminum foil, dried, and then pressed to obtain a positive electrode.

[Production of negative electrode]
50 g of Si fine particles having an average particle diameter of 0.2 μm and 2000 g of flaky graphite having an average particle diameter of 35 μm
The mixture was dispersed in, put into a hybridization system (manufactured by Nara Machinery Co., Ltd.), and processed by circulating or staying in the apparatus at a rotor rotational speed of 7000 rpm for 180 seconds to obtain a composite of Si and graphite particles. The obtained composite was mixed with coal tar pitch as an organic compound to be a carbonaceous material so that the coverage after firing was 7.5%, and kneaded and dispersed by a biaxial kneader. The obtained dispersion was introduced into a firing furnace and fired at 1000 ° C. for 3 hours in a nitrogen atmosphere. The fired product obtained was further pulverized with a hammer mill and then sieved (45 μm) to prepare a negative electrode active material. The silicon element content, average particle diameter d50, tap density, and specific surface area measured by the measurement method were 2.0% by mass, 20 μm, 1.0 g / cm ³ , and 7.2 m ² / g, respectively. .

97.5 parts by mass of the negative electrode active material, 1 part by mass of an aqueous dispersion of sodium carboxymethylcellulose (concentration of 1% by mass of sodium carboxymethylcellulose) as a thickener and binder, and an aqueous dispersion of styrene-butadiene rubber (
1.5 parts by mass of styrene-butadiene rubber (concentration: 50% by mass) was added and mixed with a disperser to form a slurry. This slurry was uniformly applied to one side of a 10 μm thick copper foil, dried, and then pressed to obtain a negative electrode.

[Manufacture of non-aqueous electrolyte batteries (laminate type)]
The positive electrode, the negative electrode, and the polyolefin separator were laminated in the order of the negative electrode, the separator, and the positive electrode. The battery element thus obtained is wrapped in an aluminum laminate film,
After injecting an electrolyte solution to be described later, it was vacuum-sealed to produce a sheet-like non-aqueous electrolyte secondary battery.

<Evaluation of non-aqueous electrolyte secondary battery>
[High-temperature cycle test]
In a constant temperature bath at 25 ° C., a non-aqueous electrolyte secondary battery of a laminate type cell was charged at a constant current-constant voltage up to 4.0 V with a current corresponding to 0.05C. Then, it discharged to 2.5V at 0.05C. Then, after CC-CV to 4.0V at 0.2C, it discharged to 2.5V at 0.2C, and stabilized the non-aqueous electrolyte secondary battery. Then, after performing CC-CV charge to 4.2V at 0.2C, it discharged to 2.5V at 0.2C and performed the initial conditioning.

The cell after initial conditioning is CCC up to 4.2V at 0.5C in a 45 ° C constant temperature bath.
The process of discharging to 2.5 V at a constant current of 0.5 C after charging V is 10 cycles.
Zero cycles were performed. The capacity at the 100th cycle was defined as “capacity after 100th cycle”. Moreover, the thickness of the battery before and after the cycle was measured. The change in battery thickness associated with the cycle was defined as “battery swelling”.
Table 3 below shows the capacity after 100 cycles and battery swelling, normalized by the value of Comparative Example 3-A-1.

<Example 3-B-1 to 3-B-2, Comparative Example 3-B-1 to 3-B-3>
[Preparation of non-aqueous electrolyte]
In a dry argon atmosphere, 1 mol / L (as a concentration in a non-aqueous electrolyte) of LiPF ₆ sufficiently dried was dissolved in a mixture of ethylene carbonate and diethyl carbonate (DEC) (volume ratio 3: 7). (This is referred to as reference electrolyte solution 3-B). A compound was added to the entire reference electrolyte solution 3-B at a ratio shown in Table 4 below to prepare an electrolyte solution. However, Comparative Example 3-B-1 is the reference electrolyte solution 3-B itself.

[Production of positive electrode]
Lithium / nickel / cobalt / manganese composite oxide (NMC) 85 as positive electrode active material
A slurry was prepared by mixing 10% by mass of acetylene black as a conductive material and 5% by mass of polyvinylidene fluoride (PVdF) as a binder in a N-methylpyrrolidone solvent with a disperser. This was uniformly applied to both sides of a 21 μm thick aluminum foil, dried, and then pressed to obtain a positive electrode.

[Production of negative electrode]
50 g of Si fine particles having an average particle diameter of 0.2 μm and 2000 g of flaky graphite having an average particle diameter of 35 μm
The mixture was dispersed in, put into a hybridization system (manufactured by Nara Machinery Co., Ltd.), and processed by circulating or staying in the apparatus at a rotor rotational speed of 7000 rpm for 180 seconds to obtain a composite of Si and graphite particles. The obtained composite was mixed with coal tar pitch as an organic compound to be a carbonaceous material so that the coverage after firing was 7.5%, and kneaded and dispersed by a biaxial kneader. The obtained dispersion was introduced into a firing furnace and fired at 1000 ° C. for 3 hours in a nitrogen atmosphere. The fired product obtained was further pulverized with a hammer mill and then sieved (45 μm) to prepare a negative electrode active material. The silicon element content, average particle diameter d50, tap density, and specific surface area measured by the measurement method were 2.0% by mass, 20 μm, 1.0 g / cm ³ , and 7.2 m ² / g, respectively. .

97.5 parts by mass of the negative electrode active material, 1 part by mass of an aqueous dispersion of sodium carboxymethylcellulose (concentration of 1% by mass of sodium carboxymethylcellulose) as a thickener and binder, and an aqueous dispersion of styrene-butadiene rubber (
1.5 parts by mass of styrene-butadiene rubber (concentration: 50% by mass) was added and mixed with a disperser to form a slurry. This slurry was uniformly applied to one side of a 10 μm thick copper foil, dried, and then pressed to obtain a negative electrode.

[Manufacture of non-aqueous electrolyte batteries (laminate type)]
The positive electrode, the negative electrode, and the polyolefin separator were laminated in the order of the negative electrode, the separator, and the positive electrode. The battery element thus obtained is wrapped in an aluminum laminate film,
After injecting an electrolyte solution to be described later, it was vacuum-sealed to produce a sheet-like non-aqueous electrolyte secondary battery.

<Evaluation of non-aqueous electrolyte secondary battery>
[High-temperature cycle test]
In a constant temperature bath at 25 ° C., a non-aqueous electrolyte secondary battery of a laminate type cell was charged at a constant current-constant voltage up to 4.0 V with a current corresponding to 0.05C. Then, it discharged to 2.5V at 0.05C. Then, after CC-CV to 4.0V at 0.2C, it discharged to 2.5V at 0.2C, and stabilized the non-aqueous electrolyte secondary battery. Then, after performing CC-CV charge to 4.2V at 0.2C, it discharged to 2.5V at 0.2C and performed the initial conditioning.

The cell after initial conditioning is CCC up to 4.2V at 0.5C in a 45 ° C constant temperature bath.
The process of discharging to 2.5 V at a constant current of 0.5 C after charging V is 10 cycles.
Zero cycles were performed. The capacity at the 100th cycle was defined as “capacity after 100th cycle”. Moreover, the thickness of the battery before and after the cycle was measured. The change in battery thickness associated with the cycle was defined as “battery swelling”.
Table 4 below shows the capacity after 100 cycles and battery swelling, normalized by the value of Comparative Example 3-B-1.

<Examples 4-1 to 4-7, Comparative Examples 4-1 to 4-3>
[Preparation of non-aqueous electrolyte]
In a dry argon atmosphere, 1 mol / L (as a concentration in a non-aqueous electrolyte) of LiPF ₆ sufficiently dried was dissolved in a mixture of ethylene carbonate and diethyl carbonate (DEC) (volume ratio 3: 7). Furthermore, 2.0% by mass of vinylene carbonate (VC) and fluoroethylene carbonate was added (this is referred to as reference electrolyte solution 4). A compound was added to the entire reference electrolyte solution 4 at a ratio shown in Table 5 below to prepare an electrolyte solution. However, Comparative Example 4-1 is the reference electrolyte 4 itself.

[Production of positive electrode]
Lithium / nickel / cobalt / manganese composite oxide (NMC) 85 as positive electrode active material
A slurry was prepared by mixing 10% by mass of acetylene black as a conductive material and 5% by mass of polyvinylidene fluoride (PVdF) as a binder in a N-methylpyrrolidone solvent with a disperser. This was uniformly applied to both sides of a 21 μm thick aluminum foil, dried, and then pressed to obtain a positive electrode.

[Production of negative electrode]
50 g of Si fine particles having an average particle diameter of 0.2 μm and 2000 g of flaky graphite having an average particle diameter of 35 μm
The mixture was dispersed in, put into a hybridization system (manufactured by Nara Machinery Co., Ltd.), and processed by circulating or staying in the apparatus at a rotor rotational speed of 7000 rpm for 180 seconds to obtain a composite of Si and graphite particles. The obtained composite was mixed with coal tar pitch as an organic compound to be a carbonaceous material so that the coverage after firing was 7.5%, and kneaded and dispersed by a biaxial kneader. The obtained dispersion was introduced into a firing furnace and fired at 1000 ° C. for 3 hours in a nitrogen atmosphere. The fired product obtained was further pulverized with a hammer mill and then sieved (45 μm) to prepare a negative electrode active material. The silicon element content, average particle diameter d50, tap density, and specific surface area measured by the measurement method were 2.0% by mass, 20 μm, 1.0 g / cm ³ , and 7.2 m ² / g, respectively. .

97.5 parts by mass of the negative electrode active material, 1 part by mass of an aqueous dispersion of sodium carboxymethylcellulose (concentration of 1% by mass of sodium carboxymethylcellulose) as a thickener and binder, and an aqueous dispersion of styrene-butadiene rubber (
1.5 parts by mass of styrene-butadiene rubber (concentration: 50% by mass) was added and mixed with a disperser to form a slurry. This slurry was uniformly applied to one side of a 10 μm thick copper foil, dried, and then pressed to obtain a negative electrode.

[Manufacture of non-aqueous electrolyte batteries (laminate type)]
The positive electrode, the negative electrode, and the polyolefin separator were laminated in the order of the negative electrode, the separator, and the positive electrode. The battery element thus obtained is wrapped in an aluminum laminate film,
After injecting an electrolyte solution to be described later, it was vacuum-sealed to produce a sheet-like non-aqueous electrolyte secondary battery.

<Evaluation of non-aqueous electrolyte secondary battery>
[High temperature storage test]
In a constant temperature bath at 25 ° C., a non-aqueous electrolyte secondary battery of a laminate type cell was charged at a constant current-constant voltage up to 4.0 V with a current corresponding to 0.05C. Then, it discharged to 2.5V at 0.05C. Next, after CC-CV to 4.0V at 0.2C, discharge to 2.5V at 0.2C, CC-CV to 4.2V at 0.2C, and then discharge to 2.5V at 0.2C The non-aqueous electrolyte secondary battery was stabilized. Then, after performing CC-CV charge to 4.3V at 0.2C, it discharged to 2.5V at 0.2C and performed the initial conditioning.

The cell after the initial conditioning was stored at a high temperature at 60 ° C. for 168 hours. After sufficiently cooling the battery, the volume was measured by immersing in an ethanol bath, and the amount of generated gas was determined from the volume change before and after the storage test, and this was defined as “amount of storage gas”. Also, 0.2C at 25 ° C
Was discharged to 2.5V, and the capacity after high-temperature storage characteristics evaluation was obtained.
It was.
Table 5 below shows the amount of storage gas and the 0.2 C capacity after storage, normalized by the values of Comparative Example 4-1.

<Example 5-1 and Comparative Example 5-1>
[Preparation of non-aqueous electrolyte]
Li in a dry argon atmosphere was sufficiently dried in a mixture with ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate (DEC) (volume / volume ratio 3: 4: 3).
PF ₆ was dissolved at 1.2 mol / L (as a concentration in the non-aqueous electrolyte), and vinylene carbonate (VC), fluoroethylene carbonate, and adiponitrile were each added to 2.5 mol / L.
1.0% by mass (referred to as reference electrolyte 5). A compound was added to the entire reference electrolyte solution 5 at a ratio shown in Table 6 below to prepare an electrolyte solution. However, Comparative Example 5-1
Is the reference electrolyte 5 itself.

[Production of positive electrode]
97% by mass of lithium cobaltate (LiCoO ₂ ) as a positive electrode active material, 1.5% by mass of acetylene black as a conductive material, and polyvinylidene fluoride (PVdF) as a binder.
5% by mass was mixed with a disperser in an N-methylpyrrolidone solvent to form a slurry. This was uniformly applied to both sides of a 21 μm thick aluminum foil, dried, and then pressed to obtain a positive electrode.

[Production of negative electrode]
98 parts by mass of graphite powder as the negative electrode active material, 1 part by mass of aqueous dispersion of sodium carboxymethylcellulose (concentration of 1% by mass of sodium carboxymethylcellulose) as the thickener and binder, respectively, and aqueous dispersion of styrene-butadiene rubber 1 part by mass (concentration of styrene-butadiene rubber 50% by mass) was added and mixed with a disperser to form a slurry. This slurry was uniformly applied to one side of a 12 μm thick copper foil, dried, and then pressed to obtain a negative electrode.

[Manufacture of non-aqueous electrolyte batteries (laminate type)]
The positive electrode, the negative electrode, and the polyolefin separator were laminated in the order of the negative electrode, the separator, the positive electrode, the separator, and the negative electrode. The battery element thus obtained was wrapped in an aluminum laminate film, injected with an electrolyte solution described later, and then vacuum sealed to produce a sheet-like non-aqueous electrolyte secondary battery.

<Evaluation of non-aqueous electrolyte secondary battery>
[Continuous Charging Test] The nonaqueous electrolyte battery after the initial capacity evaluation was performed at 60 ° C.
A continuous charge test was performed by performing CC-CV charge (cut for 168 hours) to 4.38 V at 0.2 C. Thereafter, the battery was sufficiently cooled and then immersed in an ethanol bath to measure the volume, and the “continuous charge gas amount” was determined from the volume change before and after the continuous charge.
Table 6 below shows the amount of continuous charge gas normalized by the value of Comparative Example 5-1.

<Example 6-1 and Comparative Example 6-1>
[Preparation of non-aqueous electrolyte]
Under a dry argon atmosphere, 1.0 mol / L (as a concentration in the non-aqueous electrolyte) of LiPF ₆ sufficiently dried in a mixture with ethylene carbonate and diethyl carbonate (DEC) (volume ratio 3: 7) (K) vinylene carbonate (VC) and (g
) Monofluoroethylene carbonate was added in an amount of 2.0% by mass (referred to as reference electrolyte 5). A compound was added to the entire reference electrolyte solution 6 at a ratio shown in Table 7 below to prepare an electrolyte solution. However, Comparative Example 6-1 is the reference electrolyte 6 itself.

[Production of positive electrode]
97% by mass of lithium cobaltate (LiCoO ₂ ) as a positive electrode active material, 1.5% by mass of acetylene black as a conductive material, and polyvinylidene fluoride (PVdF) as a binder.
5% by mass was mixed with a disperser in an N-methylpyrrolidone solvent to form a slurry. This was uniformly applied to both sides of a 21 μm thick aluminum foil, dried, and then pressed to obtain a positive electrode.

[Production of negative electrode]
98 parts by mass of graphite powder as the negative electrode active material, 1 part by mass of aqueous dispersion of sodium carboxymethylcellulose (concentration of 1% by mass of sodium carboxymethylcellulose) as the thickener and binder, respectively, and aqueous dispersion of styrene-butadiene rubber 1 part by mass (concentration of styrene-butadiene rubber 50% by mass) was added and mixed with a disperser to form a slurry. This slurry was uniformly applied to one side of a 12 μm thick copper foil, dried, and then pressed to obtain a negative electrode.

[Manufacture of non-aqueous electrolyte batteries (laminate type)]
The positive electrode, the negative electrode, and the polyolefin separator were laminated in the order of the negative electrode, the separator, the positive electrode, the separator, and the negative electrode. The battery element thus obtained was wrapped in an aluminum laminate film, injected with an electrolyte solution described later, and then vacuum sealed to produce a sheet-like non-aqueous electrolyte secondary battery.

<Evaluation of non-aqueous electrolyte secondary battery>
[Evaluation of discharge storage characteristics]
The nonaqueous electrolyte battery after the initial capacity evaluation was performed at 25 ° C. and 0.2 V at 3.0 V.
CC-CV charge (0.05 C cut) was performed. Thereafter, high temperature storage was performed under conditions of 60 ° C. and 168 hours. The voltage before and after storage is measured, and the difference is expressed as “Voltage change after discharge storage (mV)
" After sufficiently cooling the battery, the volume was measured by immersing the battery in an ethanol bath, and the amount of generated gas was determined from the volume change before and after the storage test.

[Charge storage test]
The cell after initial capacity evaluation was again CC-CV charged to 4.35V at 0.2C,
High temperature storage was performed at 85 ° C. for 24 hours. After sufficiently cooling the battery, the volume was measured by immersion in an ethanol bath, and the amount of generated gas was determined from the volume change before and after the storage test.
Table 7 below shows the initial resistance, the voltage change after discharge storage, the discharge storage gas amount, and the charge storage gas amount normalized by the values of Comparative Example 6-1.

<Examples 7-1 to 7-2, Comparative Examples 7-1 and 7-2>
[Preparation of non-aqueous electrolyte]
Li in a dry argon atmosphere was sufficiently dried in a mixture with ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate (DEC) (volume / volume ratio 3: 4: 3).
PF ₆ was dissolved at 1.2 mol / L (as a concentration in the nonaqueous electrolytic solution), and 5.0% by mass of fluoroethylene carbonate was added (this is referred to as a reference electrolytic solution 7). A compound was added to the entire reference electrolyte solution 7 at a ratio shown in Table 8 below to prepare an electrolyte solution. However, Comparative Example 7-1 is the reference electrolyte solution 7 itself.

[Production of positive electrode]
97% by mass of lithium cobaltate (LiCoO ₂ ) as a positive electrode active material, 1.5% by mass of acetylene black as a conductive material, and polyvinylidene fluoride (PVdF) as a binder.
5% by mass was mixed with a disperser in an N-methylpyrrolidone solvent to form a slurry. This was uniformly applied to both sides of a 21 μm thick aluminum foil, dried, and then pressed to obtain a positive electrode.

[Production of negative electrode]
98 parts by weight of natural graphite powder as a negative electrode active material, 1 part by weight of an aqueous dispersion of sodium carboxymethyl cellulose (concentration of 1% by weight of sodium carboxymethyl cellulose) as a thickener and binder, and an aqueous dispersion of styrene-butadiene rubber 1 part by weight of John (concentration of styrene-butadiene rubber 50% by mass) was added and mixed with a disperser to form a slurry. This slurry was uniformly applied to one side of a 12 μm thick copper foil, dried, and then pressed to obtain a negative electrode.

[Manufacture of non-aqueous electrolyte batteries (laminate type)]
The positive electrode, the negative electrode, and the polyolefin separator were laminated in the order of the negative electrode, the separator, the positive electrode, the separator, and the negative electrode. The battery element thus obtained was wrapped in an aluminum laminate film, injected with an electrolyte solution described later, and then vacuum sealed to produce a sheet-like non-aqueous electrolyte secondary battery.

<Evaluation of non-aqueous electrolyte secondary battery>
[Initial capacity]
In a constant temperature bath at 25 ° C., the non-aqueous electrolyte secondary battery of the laminate type cell was charged with a constant current for 6 hours at a current corresponding to 0.05 C, and then discharged to 3.0 V at 0.2 C. 4.1V at 0.2C
CC-CV charge was performed until. Thereafter, aging was performed at 45 ° C. for 72 hours. Then, it discharged to 3.0V at 0.2C, and stabilized the non-aqueous electrolyte secondary battery. Furthermore, after performing CC-CV charge to 4.35V at 0.2C, it discharged to 3.0V at 0.5C, and let the discharge capacity be "initial capacity".

[Preservation test]
The cell after initial capacity evaluation was again CC-CV charged to 4.35V at 0.2C,
High temperature storage was performed at 60 ° C. for 168 hours. After sufficiently cooling the battery, the volume was measured by immersing in an ethanol bath, and the amount of generated gas was determined from the volume change before and after the storage test, and this was defined as “amount of storage gas”. Thereafter, the battery was discharged to 3.0 V at 0.2 C at 25 ° C.
After carrying out CC-CV charge to 4.35V at 2C, it discharged to 3.0V at 0.5C, and let the discharge capacity be "capacity after storage."
In Table 8 below, normalized by the value of Comparative Example 7-1, the initial capacity, the amount of gas after storage, the capacity after storage,
Indicates.

<Example 8-1 and Comparative Example 8-1>
[Preparation of non-aqueous electrolyte]
Li in a dry argon atmosphere was sufficiently dried in a mixture with ethylene carbonate, ethyl methyl carbonate, and diethyl carbonate (DEC) (volume / volume ratio 3: 4: 3).
The PF ₆ 1.2 mol / L (non-as the concentration of the aqueous electrolyte solution) is dissolved, further, (referred to as reference electrolyte 8) with the addition of fluoroethylene carbonate 5.0% by weight. A compound was added to the entire reference electrolyte solution 8 at a ratio shown in Table 9 below to prepare an electrolyte solution. However, Comparative Example 8-1 is the reference electrolyte 8 itself.

[Production of positive electrode]
97% by mass of lithium cobaltate (LiCoO ₂ ) as a positive electrode active material, 1.5% by mass of acetylene black as a conductive material, and polyvinylidene fluoride (PVdF) as a binder.
5% by mass was mixed with a disperser in an N-methylpyrrolidone solvent to form a slurry. This was uniformly applied to both sides of a 21 μm thick aluminum foil, dried, and then pressed to obtain a positive electrode.

[Production of negative electrode]
98 parts by weight of natural graphite powder as a negative electrode active material, 1 part by weight of an aqueous dispersion of sodium carboxymethyl cellulose (concentration of 1% by weight of sodium carboxymethyl cellulose) as a thickener and binder, and an aqueous dispersion of styrene-butadiene rubber 1 part by weight of John (concentration of styrene-butadiene rubber 50% by mass) was added and mixed with a disperser to form a slurry. This slurry was uniformly applied to one side of a 12 μm thick copper foil, dried, and then pressed to obtain a negative electrode.

[Manufacture of non-aqueous electrolyte batteries (laminate type)]
The positive electrode, the negative electrode, and the polyolefin separator were laminated in the order of the negative electrode, the separator, the positive electrode, the separator, and the negative electrode. The battery element thus obtained was wrapped in an aluminum laminate film, injected with an electrolyte solution described later, and then vacuum sealed to produce a sheet-like non-aqueous electrolyte secondary battery.

<Evaluation of non-aqueous electrolyte secondary battery>
[Initial rate characteristics]
In a constant temperature bath at 25 ° C., the non-aqueous electrolyte secondary battery of the laminate type cell was charged with a constant current for 6 hours at a current corresponding to 0.05 C, and then discharged to 3.0 V at 0.2 C. 4.1V at 0.2C
CC-CV charge was performed until. Thereafter, aging was performed at 45 ° C. for 72 hours. Then, it discharged to 3.0V at 0.2C, and stabilized the non-aqueous electrolyte secondary battery. Furthermore, after performing CC-CV charging to 4.35V at 0.2C, 3.0V at 0.2C and 1.0C
The capacity ratio (1.0 C capacity / 0.2 C capacity) was defined as “initial rate characteristics”.

[Rate characteristics after saving]
The cell after initial capacity evaluation was again CC-CV charged to 4.35V at 0.2C,
High temperature storage was performed at 60 ° C. for 168 hours. Then, at 25C, 0.2C.
After discharging to 0V and again performing CC-CV charging at 0.2C to 4.35V, 0.2C
The battery was discharged at 1.0 C to 3.0 V, and the capacity ratio (1.0 C capacity / 0.2 C capacity) was defined as “rate characteristics after storage”.
Table 9 below shows the initial rate characteristics and post-storage rate characteristics normalized by the values of Comparative Example 8-1.

<Examples 9-1 to 9-3, Comparative Examples 9-1 to 9-3>
[Preparation of non-aqueous electrolyte]
In a dry argon atmosphere, 1 mol / L (as a concentration in a non-aqueous electrolyte) of LiPF ₆ sufficiently dried was dissolved in a mixture of ethylene carbonate and diethyl carbonate (DEC) (volume ratio 3: 7). Furthermore, 2.0% by mass of vinylene carbonate (VC) and fluoroethylene carbonate was added (this is referred to as reference electrolyte 9). A compound was added to the entire reference electrolyte solution 9 at a ratio shown in Table 10 below to prepare an electrolyte solution. However, Comparative Example 9-1 is the reference electrolyte 9 itself.

[Production of positive electrode]
Lithium / nickel / cobalt / manganese composite oxide (NMC) 85 as positive electrode active material
A slurry was prepared by mixing 10% by mass of acetylene black as a conductive material and 5% by mass of polyvinylidene fluoride (PVdF) as a binder in a N-methylpyrrolidone solvent with a disperser. This was uniformly applied to both sides of a 21 μm thick aluminum foil, dried, and then pressed to obtain a positive electrode.

[Production of negative electrode]
50 g of Si fine particles having an average particle diameter of 0.2 μm and 2000 g of flaky graphite having an average particle diameter of 35 μm
The mixture was dispersed in, put into a hybridization system (manufactured by Nara Machinery Co., Ltd.), and processed by circulating or staying in the apparatus at a rotor rotational speed of 7000 rpm for 180 seconds to obtain a composite of Si and graphite particles. The obtained composite was mixed with coal tar pitch as an organic compound to be a carbonaceous material so that the coverage after firing was 7.5%, and kneaded and dispersed by a biaxial kneader. The obtained dispersion was introduced into a firing furnace and fired at 1000 ° C. for 3 hours in a nitrogen atmosphere. The fired product obtained was further pulverized with a hammer mill and then sieved (45 μm) to prepare a negative electrode active material. The silicon element content, average particle diameter d50, tap density, and specific surface area measured by the measurement method were 2.0% by mass, 20 μm, 1.0 g / cm ³ , and 7.2 m ² / g, respectively. .

97.5 parts by mass of the negative electrode active material, 1 part by mass of an aqueous dispersion of sodium carboxymethylcellulose (concentration of 1% by mass of sodium carboxymethylcellulose) as a thickener and binder, and an aqueous dispersion of styrene-butadiene rubber (
1.5 parts by mass of styrene-butadiene rubber (concentration: 50% by mass) was added and mixed with a disperser to form a slurry. This slurry was uniformly applied to one side of a 10 μm thick copper foil, dried, and then pressed to obtain a negative electrode.

[Manufacture of non-aqueous electrolyte batteries (laminate type)]
The positive electrode, the negative electrode, and the polyolefin separator were laminated in the order of the negative electrode, the separator, and the positive electrode. The battery element thus obtained is wrapped in an aluminum laminate film,
After injecting an electrolyte solution to be described later, it was vacuum-sealed to produce a sheet-like non-aqueous electrolyte secondary battery.

<Evaluation of non-aqueous electrolyte secondary battery>
[High temperature storage test]
In a constant temperature bath at 25 ° C., a non-aqueous electrolyte secondary battery of a laminate type cell was charged at a constant current-constant voltage up to 4.0 V with a current corresponding to 0.05C. Then, it discharged to 2.5V at 0.05C. Next, after CC-CV to 4.0V at 0.2C, discharge to 2.5V at 0.2C, CC-CV to 4.2V at 0.2C, and then discharge to 2.5V at 0.2C The non-aqueous electrolyte secondary battery was stabilized. Then, after performing CC-CV charge to 4.3V at 0.2C, it discharged to 2.5V at 0.2C and performed the initial conditioning.

The cell after the initial conditioning was stored at a high temperature at 60 ° C. for 168 hours. After sufficiently cooling the battery, the volume was measured by immersing in an ethanol bath, and the amount of generated gas was determined from the volume change before and after the storage test, and this was defined as “amount of storage gas”. Also, 0.2C at 25 ° C
Was discharged to 2.5V, and the capacity after high-temperature storage characteristics evaluation was obtained.
It was.

[High-temperature cycle test] The cell after the initial conditioning was placed in a thermostat at 45 ° C, 0.5
The process of CC-CV charging to 4.2 V at C and then discharging to 2.5 V at a constant current of 0.5 C was taken as 100 cycles, and 100 cycles were performed. The capacity at the 100th cycle was defined as “capacity after 100th cycle”.
In Table 10 below, the amount of gas after storage, normalized by the value of Comparative Example 9-1, 0.2 C capacity after storage,
The capacity after 100 cycles is shown.

According to the non-aqueous electrolyte solution of the present invention, capacity deterioration and cycle characteristics of a non-aqueous electrolyte battery during high temperature storage can be improved. Therefore, it can be suitably used in all fields such as an electronic device in which a non-aqueous electrolyte secondary battery is used.
The application of the non-aqueous electrolyte solution and the non-aqueous electrolyte secondary battery of the present invention is not particularly limited, and can be used for various known applications. Specific examples of applications include laptop computers, electronic book players, mobile phones, mobile faxes, mobile copy, mobile printers, mobile audio players, small video cameras, LCD TVs, handy cleaners, transceivers, electronic notebooks, calculators, and memories. Cards, portable tape recorders, radios, backup power supplies, automobiles, motorcycles, motorbikes, bicycles, lighting equipment, toys, game machines, watches, electric tools, strobes, cameras, etc.

Claims (10)

A non-aqueous electrolyte solution for a non-aqueous electrolyte battery comprising a positive electrode and a negative electrode capable of occluding and releasing metal ions, the non-aqueous electrolyte solution being represented by the following general formula (A) together with an electrolyte and a non-aqueous solvent A compound containing a structure, and (1) selected from the group consisting of a nitrile compound, an isocyanate compound, a difluorophosphate, a fluorosulfonate, lithium bis (fluorosulfonyl) imide, and a compound represented by the following general formula (B) A non-aqueous system comprising: (2) a cyclic carbonate compound having fluorine atoms in an amount of 0.01 to 50.0% by weight based on the total amount of the non-aqueous electrolyte solution. Electrolytic solution.

(In the formula ^(A), R 1 to R ³ is an optionally substituted group organic group having 1 to 20 carbon atoms, ^and at least one acrylic group R 1 to R ^3, A methacryl group or a trimethylsilyl group.)

(In Formula (B), R ¹ , R ² and R ³ each independently represents an alkyl group, alkenyl group or alkynyl group having 1 to 12 carbon atoms which may be substituted with a halogen atom, and n represents 0
Represents an integer of ~ 6. ) The addition amount of the compound containing the structure represented by the general formula (A) is 0.01 wt% or more and 10.0 wt% or less with respect to the total amount of the non-aqueous electrolyte solution. The non-aqueous electrolyte solution described in 1. The nitrile compound, isocyanate compound, difluorophosphate, fluorosulfonate, lithium bis (fluorosulfonyl) imide and the compound represented by the following general formula (B) are 0.01% relative to the total amount of the non-aqueous electrolyte solution. The non-aqueous electrolyte solution according to claim 1 or 2, wherein the non-aqueous electrolyte solution is not less than wt% and not more than 10.0 wt%. The cyclic carbonate compound having a fluorine atom is at least one compound selected from the group consisting of monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, and 4,5-difluoroethylene carbonate. The non-aqueous electrolyte solution according to claim 1. The non-aqueous electrolyte is at least one selected from the group consisting of a cyclic carbonate having a carbon-carbon unsaturated bond, an acid anhydride, a vinyl sulfonate ester, an aromatic compound having 12 or less carbon atoms, and a chain carboxylic ester. The nonaqueous electrolytic solution according to any one of claims 1 to 3, wherein the nonaqueous electrolytic solution comprises the following compound. A non-aqueous electrolyte secondary battery comprising a positive electrode capable of inserting and extracting lithium ions, a negative electrode capable of inserting and extracting lithium ions, and a non-aqueous electrolyte solution, wherein the non-aqueous electrolyte solution comprises: A nonaqueous electrolyte battery characterized by being a nonaqueous electrolyte solution according to any one of the above. The non-aqueous electrolyte battery according to claim 6, wherein the negative electrode active material of the negative electrode capable of inserting and extracting lithium ions has carbon as a constituent element. The non-aqueous electrolyte battery according to claim 6, wherein the negative electrode active material of the negative electrode capable of inserting and extracting lithium ions has silicon (Si) or tin (Sn) as a constituent element. 9. The negative electrode active material of a negative electrode capable of inserting and extracting lithium ions is a mixture or composite of particles having silicon (Si) or tin (Sn) as constituent elements and graphite particles. The non-aqueous electrolyte battery described in 1. The content of particles having silicon (Si) or tin (Sn) as a constituent element with respect to the total of the particles having silicon (Si) or tin (Sn) as a constituent element and graphite particles is 0.1 to 25% by mass. The nonaqueous electrolyte battery according to claim 9, wherein the battery is a nonaqueous electrolyte battery.