JP2020140927A - Nonaqueous electrolyte solution and energy device arranged by use thereof - Google Patents

Abstract

To provide a nonaqueous electrolyte solution which is satisfactory in the initial performance and durability performance of an energy device typified by a nonaqueous electrolytic secondary battery, especially the initial capacity, initial battery expansion, capacity-keeping rate after being stored at a high temperature, and expansion owing to high-temperature storing.SOLUTION: A nonaqueous electrolyte solution comprises an electrolyte, a nonaqueous solvent and LiHSO4, wherein the LiHSO4 content to a total quantity of the nonaqueous electrolyte solution is 0.1 mass% or less. It is preferred that the nonaqueous electrolyte solution comprises at least one particular compound selected from a group consisting of a cyclic carbonate having a fluorine atom, a cyclic carbonate having a carbon-carbon unsaturated bond, a difluorophosphate, a salt having an FSO2 structure, a compound having an isocyanato group, a compound having a cyano group, a cyclic sulfonic acid ester, and a dicarboxylic acid complex salt.SELECTED DRAWING: None

Description

The present invention relates to a non-aqueous electrolyte solution and an energy device using the same.

In a wide range of applications, from so-called consumer power supplies such as mobile phones and laptop computers to in-vehicle power supplies for driving automobiles and large stationary power supplies, non-aqueous electrolyte secondary batteries, electric double layer capacitors, lithium ion capacitors, etc. Energy devices using non-aqueous electrolyte solutions have been put into practical use. However, in recent years, the demand for higher performance of energy devices has been increasing, and especially in non-aqueous electrolyte secondary batteries, battery characteristics such as capacity and swelling have been increased.
It is required to achieve various characteristics such as input / output, impedance characteristics, charge / discharge rate characteristics, and safety at a high level not only at the initial stage but also after endurance such as after cycling and storage.

So far, as a means for improving the capacity, battery swelling, positive electrode metal elution, and safety during durability tests such as cycle characteristics and storage characteristics of non-aqueous electrolyte secondary batteries, positive electrode and negative electrode active materials have been used. Numerous technologies are being studied for the components of various batteries, including non-aqueous electrolytes.
For example, Patent Document 1 discloses a battery technique using a lithium metal having an amorphous metal nitride layer having an ion conductive layer on the surface of the negative electrode or a lithium alloy as the negative electrode active material, and various lithiums as preferable electrolytes. LiHSO ₄ while the salts are listed
Is described. Further, the preferable concentration of the lithium salt is described as 0.1 M to 2.0 M.

U.S. Patent Application Publication No. 2017-0346099

As mentioned above, while the demand for higher performance of non-aqueous electrolyte secondary batteries has increased in recent years, the performance of non-aqueous electrolyte secondary batteries has been further improved, that is, during endurance such as cycle operation and storage. It is required to reduce the battery swelling, which is related to the improvement of the capacity retention rate and the improvement of the safety. However, in the compound described in Patent Document 1 and the non-aqueous electrolyte battery using the electrolytic solution using the compound, the initial capacity and initial swelling, and the capacity retention rate and swelling suppression after durability are still sufficient. Was hard to say.

The present invention has been made in view of the background art, and an object of the present invention is to improve the initial characteristics and durability of an energy device represented by a non-aqueous electrolyte secondary battery, particularly the initial capacity and the initial capacity. An object of the present invention is to provide a non-aqueous electrolyte solution that improves the initial battery swelling, the capacity retention rate during high-temperature storage, and the storage battery swelling.

As a result of diligent studies to solve the above problems, the present inventor has added LiHSO ₄ in an amount of 0.1% by mass or less in a non-aqueous electrolyte solution containing an electrolyte and a non-aqueous solvent for dissolving the electrolyte. As a result, they have found that the initial characteristics and durability of the battery are significantly improved as compared with the prior art, and have completed the present invention.
More specifically, the present inventor aims to develop a new non-aqueous electrolyte solution that significantly improves the initial capacity, initial battery swelling, capacity retention rate during high-temperature storage, and storage battery swelling as compared with the prior art. Focusing on the formation mechanism of the negative electrode film and the elementary reaction rate of the non-aqueous electrolyte secondary battery as an energy device, various studies were conducted on the action and effect of various compounds and their combinations.
Then, the present inventor has a new idea that LiHSO ₄ is contained in a non-aqueous electrolyte solution in an amount of 0.1% by mass or less, so that the initial capacity, the initial battery swelling, the capacity retention rate at high temperature storage, and the storage battery swelling can be improved. , We have built a technology that greatly improves the conventional technology.

That is, the present invention provides the specific embodiments shown in the following [1] to [5].
[1] A non-aqueous electrolyte solution containing an electrolyte, a non-aqueous solvent and LiHSO ₄ and having a LiHSO ₄ content of 0.1% by mass or less based on the entire non-aqueous electrolyte solution.
[2] Cyclic carbonate having a fluorine atom, cyclic carbonate having a carbon-carbon unsaturated bond, difluorophosphate, salt having an FSO ₂ structure, a compound having an isocyanato group, a compound having a cyano group, a cyclic sulfonic acid ester and The non-aqueous electrolyte solution according to [1], which contains at least one specific compound selected from the group consisting of dicarboxylic acid complex salts.
[3] The non-aqueous electrolyte solution according to [1] or [2], which contains LiPF ₆ as the electrolyte.
[4] An energy device including a plurality of electrodes capable of occluding and releasing metal ions, and the non-aqueous electrolyte solution according to any one of [1] to [3].
[5] The energy device according to [4], wherein the plurality of electrodes capable of occluding and releasing the metal ions are a positive electrode and a negative electrode, and the negative electrode includes a carbonaceous material or a material containing silicon.

According to the present invention, a non-aqueous electrolyte solution capable of realizing an energy device such as a secondary battery with significantly improved initial capacity, initial battery swelling, capacity retention rate during high-temperature storage, and storage battery swelling. Can be provided. Further, according to a preferred embodiment of the present invention, a non-aqueous electrolysis capable of realizing an energy device having excellent input / output characteristics, impedance characteristics, charge / discharge rate characteristics, and further excellent cycle characteristics, continuous charging characteristics, safety, and the like. A liquid can be provided. Further, it is possible to provide an energy device using this non-aqueous electrolyte solution.

LiHSO ₄ is believed to produce modified forms such as Li ₂ SO ₄ on the electrode surface in the battery. For example, Li ₂ SO ₄ has low solubility in the electrolytic solution, high thermal stability and electrochemical stability, and can increase the Li ion concentration on the electrode surface, so that it has excellent lithium ion insertion / desorption characteristics. Moreover, it is a coating component having a high ability to suppress side reactions on the electrode surface. In order to use Li ₂ SO ₄ as a film component, a method of introducing Li ₂ SO ₄ itself into a non-aqueous electrolyte solution can be considered, but Li ₂ SO ₄ has low solubility in a non-aqueous electrolyte solution, so that a film is constructed. Is inappropriate for.

Hereinafter, embodiments of the present invention will be described in detail. The following embodiments are examples (representative examples) of embodiments of the present invention, and the present invention is not limited thereto. Further, the present invention can be arbitrarily modified and implemented without departing from the gist thereof.

<1. LiHSO ₄ >
The non-aqueous electrolyte solution according to the embodiment of the present invention contains LiHSO ₄ . The content of LiHSO ₄ is usually 0.0001% by mass or more, preferably 0.0005% by mass or more, more preferably 0.001% by mass or more, when the total amount of the non-aqueous electrolyte solution is 100% by mass. ,
It is 0.1% by mass or less, preferably 0.05% by mass or less, and more preferably 0.03% by mass or less. Within the above range, it is preferable to further improve the initial capacity and the capacity retention rate after endurance such as after storage and after cycling, and to further reduce the battery swelling after initial and endurance.

The preparation of the non-aqueous electrolyte solution containing LiHSO ₄ may be carried out by a known method and is not particularly limited. For example, a method of adding LiHSO ₄ to a non-aqueous electrolyte solution, a method of adding LiHSO ₄ to a solvent and then dissolving the electrolyte salt to obtain a non-aqueous electrolyte solution, a method of adding LiHSO _4- containing electrolyte salt and additives, etc. Examples thereof include a method of introducing into an aqueous solvent. In the present invention, any method may be used.

The non-aqueous electrolytic solution of the state LiHSO ₄ is contained, even particularly limited as long as it is contained in LiHSO ₄ is not the sole, not completely dissolved in LiHSO ₄ nonaqueous solvent and a nonaqueous electrolytic solution, Li
HSO ₄ may be partially insoluble at a saturation concentration of a non-aqueous solvent or a non-aqueous electrolyte solution or higher. Further, the electrolyte salt or the additive, which is a component other than LiHSO ₄ , may be partially insoluble in the non-aqueous solvation non-aqueous electrolyte solution at a saturation concentration or higher. In such an insoluble case, the insoluble component may be injected into the battery as it is, or the insoluble component may be once removed by filtration or the like.
The method for producing LiHSO ₄ is not particularly limited, and known methods can be combined for production.

<2. Specific compound>
Nonaqueous electrolyte which is one embodiment of the present invention, cyclic carbonates having a fluorine atom, a carbon - cyclic carbonate having a carbon-carbon unsaturated bond, difluorophosphate, salts having a FSO ₂ structure, a compound having an isocyanato group, It preferably contains at least one specific compound selected from the group consisting of a compound having a cyano group, a cyclic sulfonic acid ester and a dicarboxylic acid complex salt.

The reason for this is presumed as follows. The LiHSO _{4 according} to the present invention produces a modified product such as Li ₂ SO ₄ on the surface of the electrode in the battery and exhibits various excellent effects as described above. When LiHSO ₄ is denatured at the molecular level, if a film component derived from a specific compound is present around it, an electrostatic intermolecular interaction acts between LiHSO ₄ and the film component derived from the specific compound, and the film is formed. It becomes easier to stabilize. As a result, the solubility of the electrolytic solution is lower than that of LiHSO ₄ alone, the thermal stability and the electrochemical stability are high, the lithium ion insertion / desorption characteristics are excellent, and the side reaction suppression ability on the electrode surface is high. It becomes a film.

All of the specific compounds according to the present invention are LiH among the plurality of electrodes of the energy device.
Interact with degeneration of SO _4, is considered to be concerted to form a suitable coating on the structure in the electrode reaction. This action / principle is not limited to the action / principle described below, but the present inventor speculates as follows. (I) Cyclic carbonate having a fluorine atom, (i)
i) Cyclic carbonate with carbon-carbon unsaturated bond, (iii) difluorophosphate,
(Iv) salts with FSO ₂ structure, (v) a compound having an isocyanato group, (vi) a compound having a cyano group, (vii) cyclic sulfonic acid ester, and the (viii) a dicarboxylic acid complex salt, electrolyte component The putative reaction mechanism with the nucleophilic species Nu ⁻ formed by the electrochemical reduction of the above is shown below.

In the above reaction formula, Cat is a cation constituting a salt. Q ¹ is a divalent organic group containing fluorine, Q ² is a divalent organic group containing a carbon-carbon unsaturated bond, Q ^{3 to} Q ⁵ are monovalent organic groups, and Q ⁶
Represent each a divalent organic group, Q ⁷ represents a single bond or a divalent organic group, X is a divalent organic group comprising a complex central element.
As shown in the reaction formula, each specific compound contains a nucleophilic attack receiving site, and each of the indicated reactions is used as an initiating reaction to form a coating-like structure that favorably supports the electrode reaction. It is estimated to be.

The molecular weight of the specific compound is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired, but those of 50 or more and 250 or less are preferable. Within this range, the solubility of the specific compound in the non-aqueous electrolyte solution is good, and the effect of the addition can be sufficiently exhibited.
Further, the method for producing the specific compound is not particularly limited, and a known method can be arbitrarily selected for production. Moreover, you may use the commercially available one.
Further, as the specific compound, any one of them may be contained alone in the non-aqueous electrolyte solution of the present invention, or two or more of them may be coexisted in any combination and ratio.

<2-1. Cyclic carbonate with fluorine atom>
Among the specific compounds, the cyclic carbonate having a fluorine atom (hereinafter, may be abbreviated as "fluorinated cyclic carbonate") is not particularly limited as long as it has a fluorine atom, and any fluorinated cyclic carbonate can be used. Can be used.
Examples of the fluorinated cyclic carbonate include derivatives of cyclic carbonate having an alkylene group having 2 to 6 carbon atoms, and examples thereof are ethylene carbonate derivatives. Examples of the ethylene carbonate derivative include ethylene carbonate or a fluorinated product of ethylene carbonate substituted with an alkyl group (for example, an alkyl group having 1 to 4 carbon atoms), and among them, those having 1 to 8 fluorine atoms. Is preferable.

Specifically, 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-5,5
-Dimethylethylene carbonate and the like.

Among them, at least one selected from the group consisting of monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, 4,5-difluoroethylene carbonate and 4,5-difluoro-4,5-dimethylethylene carbonate has high ionic conductivity. It is more preferable in that it imparts properties and preferably forms an interface protective film.
As the fluorinated cyclic carbonate, one type may be used alone, or two or more types may be used in combination in any combination and ratio. The content of the fluorinated cyclic carbonate is not particularly limited.
It is optional as long as the effect of the present invention is not significantly impaired, but is usually 0.001% by mass or more, preferably 0.01% by mass or more, and more preferably 0.1% by mass in 100% by mass of the non-aqueous electrolyte solution. It is usually 8% by mass or less, preferably 6% by mass or less, and more preferably 5% by mass or less. Within this range, the non-aqueous electrolyte secondary battery tends to exhibit sufficient cycle characteristics and high temperature storage characteristics. Within this range, the non-aqueous electrolyte secondary battery tends to exhibit sufficient cycle characteristics and high temperature storage characteristics.

The fluorinated cyclic carbonate may be used as an auxiliary agent for the non-aqueous electrolyte solution or as a non-aqueous solvent. The content of fluorinated cyclic carbonate when used as a non-aqueous solvent is
In 100% by mass of the non-aqueous electrolyte solution, it is usually 8% by mass or more, preferably 10% by mass or more, more preferably 12% by mass or more, and usually 85% by mass or less, preferably 80% by mass. % Or less, more preferably 75% by mass or less. Within this range, the non-aqueous electrolyte secondary battery tends to exhibit a sufficient effect of improving cycle characteristics, and it is easy to avoid a decrease in the discharge capacity retention rate.

<2-2. Cyclic carbonate with carbon-carbon unsaturated bond>
Among the specific compounds, the cyclic carbonate having a carbon-carbon unsaturated bond (hereinafter, may be abbreviated as "unsaturated cyclic carbonate") is particularly limited as long as it is a cyclic carbonate having a carbon-carbon unsaturated bond. Instead, carbonates with any carbon-carbon unsaturated bond can be used. The cyclic carbonate having a substituent having an aromatic ring is also included in the cyclic carbonate having a carbon-carbon unsaturated bond. The method for producing the unsaturated cyclic carbonate is not particularly limited, and a known method can be arbitrarily selected for production.

Examples of the unsaturated cyclic carbonate include vinylene carbonates, ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon unsaturated bond, phenyl carbonates, vinyl carbonates, allyl carbonates and the like.
Examples of vinylene carbonates include vinylene carbonate, methylvinylene carbonate, 4,5-dimethylvinylene carbonate, phenylvinylene carbonate, 4,5-.
Examples thereof include diphenylvinylene carbonate, vinyl vinylene carbonate and allyl vinylene carbonate.

Specific examples of ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon unsaturated bond include vinyl ethylene carbonate, 4,5-divinylethylene carbonate, phenylethylene carbonate, 4,5-diphenylethylene carbonate, and the like. Examples thereof include ethynyl ethylene carbonate and 4,5-dietinyl ethylene carbonate.
Of these, vinylene carbonates, ethylene carbonate substituted with a substituent having an aromatic ring or a carbon-carbon unsaturated bond are preferable, and vinylene carbonate, 4,5-diphenylvinylene carbonate, 4,5-dimethylvinylene carbonate, and vinyl are particularly preferable. Ethylene carbonate or ethynyl ethylene carbonate is more preferably used because it forms a stable interfacial protective coating.

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 of unsaturated cyclic carbonate is usually 50 or more, preferably 80.
It is usually 250 or less, preferably 150 or less. Within this range, the solubility of the unsaturated cyclic carbonate in the non-aqueous electrolyte solution can be easily ensured, and the effect of the present invention can be sufficiently exhibited.

As the unsaturated cyclic carbonate, one type may be used alone, or two or more types may be used in any combination and ratio. The content 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 content of the unsaturated cyclic carbonate is usually 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and further, in 100% by mass of the non-aqueous electrolyte solution. It is preferably 0.2% by mass or more, and usually 10% by mass or less, preferably 8% by mass or less, and more preferably 5% by mass or less. Within the above range, the non-aqueous electrolyte secondary battery tends to exhibit sufficient high-temperature storage characteristics and cycle characteristic improving effects.

<2-3. Difluorophosphate ＞
Among the specific compounds, the difluorophosphate is not particularly limited as long as it is a salt having a difluorophosphate anion as a constituent element, and any difluorophosphate can be used.
Examples of difluorophosphate include lithium difluorophosphate (sometimes abbreviated as LiPO ₂ F ₂ ), sodium difluorophosphate, potassium difluorophosphate, ammonium difluorophosphate and the like.

Among them, lithium difluorophosphate is preferable, and it can contribute to the formation of a stable film-like structure, and is more preferably used.
The content of the difluorophosphate is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is preferably 0.001% by mass or more with respect to the non-aqueous electrolyte solution of the present invention.
.. It is 0% by mass or less.

When the content of the difluorophosphate is not more than this lower limit, a sufficient effect of improving the cycle characteristics can be brought to the non-aqueous electrolyte secondary battery. Further, when it is not more than this upper limit, it is possible to avoid an increase in the manufacturing cost of the non-aqueous electrolyte secondary battery. The content of difluorophosphate is more preferably 0.01% by mass or more, further preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, and even more preferably 1.5% by mass or less. , More preferably 1.2
It is mass% or less, particularly preferably 1.1 mass% or less.

<2-4. Salt with FSO ₂ structure>
Of particular compound, the salt having a FSO ₂ structure, as long as salt and anion components with FSO ₂ structure is not particularly limited, and may be a salt with any FSO ₂ structure.
An example of a salt having an FSO ₂ structure is lithium fluorosulfonate (hereinafter referred to as FSO ₃ L).
(Sometimes abbreviated as i), sodium fluorosulfonate, potassium fluorosulfonate, ammonium fluorosulfonate, (FSO ₂ ) ₂ NLi, (FSO ₂ ) (CF ₃ S)
Examples thereof include O ₂ ) NLi, (FSO ₂ ) (CF ₃ CF ₂ SO ₂ ) NLi and the like.

Among them, lithium fluorosulfonic acid and (FSO ₂₎ 2 _NLi are preferred, can contribute to the formation of a stable film-like structures, more preferably used.
The content of the salt having the FSO ₂ structure is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is preferably 0.001% by mass or more with respect to the non-aqueous electrolyte solution of the present invention. It is 8.0% by mass or less. When the content of the salt having the FSO ₂ structure is equal to or higher than this lower limit,
It is possible to bring about a sufficient effect of improving cycle characteristics for a non-aqueous electrolyte secondary battery. Also,
When it is not more than this upper limit, it is possible to avoid an increase in the manufacturing cost of the non-aqueous electrolyte secondary battery. When the salt having the FSO ₂ structure is FSO ₃ Li, the content is more preferably 0.0.
1% by mass or more, more preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, still more preferably 3.0% by mass or less, still more preferably 2.5% by mass or less, particularly preferably. It is 2.0% by mass or less.

<2-5. Compounds with isocyanato groups>
Among the specific compounds, the compound having an isocyanato group (hereinafter, may be abbreviated as "isocyanate") is not particularly limited, and any isocyanate can be used.
Examples of isocyanates include monoisocyanates, diisocyanates, triisocyanates and the like.

Specific examples of monoisocyanates include isocyanatomethane, isocyanatoethane, and so on.
1-isocyanatopropane, 1-isocyanatobutane, 1-isocyanatopentane, 1-
Isocyanatohexane, 1-isocyanatoheptane, 1-isocyanatooctane, 1-isocyanatononan, 1-isocyanatodecane, isocyanatocyclohexane, methoxycarbonyl isocyanate, ethoxycarbonylisocyanate, propoxycarbonylisocyanate, butoxycarbonylisocyanate, methoxysulfonyl Examples thereof include isocyanate, ethoxysulfonyl isocyanate, propoxysulfonyl isocyanate, butoxysulfonyl isocyanate and fluorosulfonyl isocyanate.

Specific examples of diisocyanates include 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, 1,6-diisocyanatohexane, 1,7-diisocyanatoheptane, and 1,8-diisocyanate. Natooctane, 1,9-diisocyanatononan, 1,10-diisocyanatodecane, 1,3-diisocyanatopropene, 1,4-diisocyanato-2-butane, 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, toluenediisocyanate, xylene diisocyanate, tolylene diisocyanate, 1,2-bis (isocyanatomethyl) cyclohexane, 1,3-bis (isocyanatomethyl) ) Cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, 1,2-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane, dicyclohexylmethane-1,1'- Diisocyanate, dicyclohexanemethane-2,2'-diisocyanate,
Dicyclohexylmethane-3,3'-diisocyanate, dicyclohexylmethane-4,4
'-Diisocyanate, isophorone diisocyanate, bicyclo [2.2.1] heptane-2,5-diylbis (methyl = isocyanate), bicyclo [2.2.1] heptane-
Examples thereof include 2,6-diylbis (methyl = isocyanate), 2,4,4-trimethylhexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate.

Specific examples of triisocyanates include 1,6,11-triisocyanatoundecane, 4-isocyanatomethyl-1,8-octamethylene diisocyanate, 1,3,5-triisocyanatemethylbenzene, 1,3,5. -Tris (6-isocyanatohexa-1-
Il) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 4- (
Isocyanatomethyl) octamethylene = diisocyanate and the like.

Among them, 1,6-diisocyanatohexane, 1,3-bis (isocyanatomethyl) cyclohexane, 1,3,5-tris (6-isocyanatohexa-1-yl) -1,3,5-yl.
Triazine-2,4,6 (1H, 3H, 5H) -trione, 2,4,4-trimethylhexamethylenediisocyanate, 2,2,4-trimethylhexamethylenediisocyanate are industrially readily available. It is preferable in that the production cost of the electrolytic solution can be kept low, and it can contribute to the formation of a stable film-like structure from a technical point of view, and is more preferably used.

The content of isocyanate is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is preferably 0.001% by mass or more, 1.0, based on the non-aqueous electrolyte solution of the present invention.
It is mass% or less.
When the isocyanate content is at least this lower limit, it is possible to bring about a sufficient effect of improving the cycle characteristics in the non-aqueous electrolyte secondary battery. Further, when it is not more than this upper limit, the initial resistance increase of the non-aqueous electrolyte secondary battery can be avoided. The isocyanate content is more preferably 0.01% by mass or more, further preferably 0.1% by mass or more, and particularly preferably 0.2.
It is mass% or more, more preferably 0.8 mass% or less, still more preferably 0.7 mass% or less, and particularly preferably 0.6 mass% or less.

<2-6. Compound with cyano group>
Among the specific compounds, the compound having a cyano group (hereinafter, may be abbreviated as "nitrile") is not particularly limited, and any nitrile can be used.
Examples of nitriles include mononitriles, dinitriles and the like.
Specific examples of mononitriles include acetonitrile, propionitrile, butyronitrile, isobutyronitrile, valeronitrile, isovaleronitrile, lauronitrile, 2-
Methylbutyronitrile, trimethylnitrile, hexanenitrile, cyclopentanecarbonitrile, cyclohexanecarbonitrile, acrylonitrile, methacrylonitrile, crotononitrile, 3-methylcrotononitrile, 2-methyl-2-butennitril, 2-pentene Nitrile, 2-Methyl-2-pentenenitrile, 3-Methyl-2-pentenenitrile, 2-hexenenitrile, fluoronitrile, difluoronitrile, trifluoronitrile, 2-fluoropropionitrile, 3-fluoropropionitrile, 2 , 2-Difluoropropionitrile, 2,3-difluoropropionitrile, 3,3-difluoropropionitrile, 2,2,3-trifluoropropionitrile, 3,3,3-trifluoropropionitrile, 3,3 3'-oxydipropionitrile,
3,3'-thiodipropionitrile, 1,2,3-propanetricarbonitrile, 1,3
, 5-Pentane tricarbonitrile, pentafluoropropionitrile and the like.

Specific examples of dinitriles include malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimeronitrile, suberonitrile, azelanitrile, sebaconitrile, undecandinitrile, dodecandinitrile, methylmalononitrile, ethylmalononitrile, isopropylmalononitrile, and tert-. Butylmalononitrile, methylsuccinonitrile, 2,2-dimethylsuccinonitrile, 2,3-dimethylsuccinonitrile, 2,3,3-trimethylsuccinonitrile, 2,2,3,3-tetramethylsuccino Nitrile, 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-Tetramethylglutaronitrile, Maleonitrile, Fumaronitrile,
1,4-Dicyanopentane, 2,6-dicyanoheptane, 2,7-dicyanooctane, 2
, 8-Dicyanononane, 1,6-dicyanodecane, 1,2-Dicyanobenzene, 1,3-
Examples thereof include dicyanobenzene, 1,4-dicyanobenzene, 3,3'-(ethylenedioxy) dipropionitrile, and 3,3'-(ethylenedithio) dipropionitrile.

Among them, dinitriles such as malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimeronitrile, suberonitrile, azelanitrile, sebaconitrile, undecanenitrile, and dodecanedinitrile can contribute to the formation of stable film-like structures. More preferably used.
The content of nitrile is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is preferably 0.001% by mass or more and 5.0% by mass with respect to the non-aqueous electrolyte solution of the present invention.
It is as follows.

When the nitrile content is at least this lower limit, it is possible to bring about a sufficient effect of improving the cycle characteristics in the non-aqueous electrolyte secondary battery. Further, when it is not more than this upper limit, it is possible to avoid an increase in the initial resistance of the non-aqueous electrolyte secondary battery and suppress deterioration of the rate characteristics. The content of nitrile is more preferably 0.01% by mass or more, further preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, still more preferably 4.0% by mass or less, still more preferably. Is 3
.. It is 0% by mass or less, particularly preferably 2.5% by mass or less.

<2-7. Cyclic sulfonic acid ester>
Among the specific compounds, the cyclic sulfonic acid ester is not particularly limited, and any cyclic sulfonic acid ester can be used.
Examples of the cyclic sulfonic acid ester include saturated cyclic sulfonic acid ester, unsaturated cyclic sulfonic acid ester and the like.

Specific examples of the saturated cyclic sulfonic acid ester include 1,3-propane sultone and 1-.
Fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-
Fluoro-1,3-propane sultone, 1-methyl-1,3-propane sultone, 2-methyl-1,3-propane sultone, 3-methyl-1,3-propane sultone, 1,4-butane sultone, 1- Fluoro-1,4-butansultone, 2-fluoro-1,4-butansultone, 3-fluoro-1,4-butansultone, 4-fluoro-1,4-butansultone, 1-methyl-1,4-butansultone, 2- Methyl-1,4-butansultone, 3
-Methyl-1,4-butanesulton, 4-methyl-1,4-butansulton, methylenemethanedisulfonate, ethylenemethanedisulfonate and the like can be mentioned.

Specific examples of the unsaturated cyclic sulfonic acid ester include 1-propene-1,3-sultone, 2-propene-1,3-sultone, 1-fluoro-1-propene-1,3-sultone, and 2-fluoro. -1-Propene-1,3-sultone, 3-Fluoro-1-propene-1,
3-sultone, 1-fluoro-2-propene-1,3-sultone, 2-fluoro-2-propene-1,3-sultone, 3-fluoro-2-propene-1,3-sultone, 1-methyl- 1-Propene-1,3-sultone, 2-Methyl-1-propene-1,3-sultone,
3-Methyl-1-propene-1,3-sultone, 1-methyl-2-propene-1,3-sultone, 2-methyl-2-propene-1,3-sultone, 3-methyl-2-propene- 1
, 3-Sultone, 1-Butene-1,4-Sultone, 2-Butene-1,4-Sultone, 3-
Butene-1,4-sultone, 1-fluoro-1-butene-1,4-sultone, 2-fluoro-1-butene-1,4-sultone, 3-fluoro-1-butene-1,4-sultone, 4
−Fluoro-1-butene-1,4-sultone, 1-fluoro-2-butene-1,4-sultone, 2-fluoro-2-butene-1,4-sultone, 3-fluoro-2-butene-1 ，
4-sultone, 4-fluoro-2-butene-1,4-sultone, 1-fluoro-3-butene-1,4-sultone, 2-fluoro-3-butene-1,4-sultone, 3-fluoro-
3-Butene-1,4-sultone, 4-Fluoro-3-butene-1,4-sultone, 1-methyl-1-butene-1,4-sultone, 2-methyl-1-butene-1,4- Sultone, 3
-Methyl-1-butene-1,4-sultone, 4-methyl-1-butene-1,4-sultone, 1-methyl-2-butene-1,4-sultone, 2-methyl-2-butene-1 , 4-Sultone, 3-Methyl-2-butene-1,4-Sultone, 4-Methyl-2-butene-1,4-
Sultone, 1-methyl-3-butene-1,4-sultone, 2-methyl-3-butene-1,
4-sultone, 3-methyl-3-butene-1,4-sultone, 4-methyl-3-butene-
Examples include 1,4-sultone.

Among the above, 1,3-propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone, methylene methanedisulfonate, Ethylene methanedisulfonate, 1-propen-
1,3-Sultone is more preferably used because it is easily available and can contribute to the formation of a stable film-like structure.

The content of the cyclic sulfonic acid ester is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is preferably 0.001% by mass or more in 100% by mass of the non-aqueous electrolyte solution of the present invention. It is 0.0% by mass or less.
When the content of the cyclic sulfonic acid ester is not more than this lower limit, a sufficient effect of improving the cycle characteristics can be brought to the energy device. Further, when it is not more than this upper limit, it is possible to avoid an increase in the manufacturing cost of the energy device. The content of the cyclic sulfonic acid ester is more preferably 0.01% by mass or more, further preferably 0.1% by mass or more, particularly preferably 0.2% by mass or more, and even more preferably 5.0% by mass or less. , More preferably 3
.. It is 0% by mass or less, particularly preferably 2.0% by mass or less.

<2-8. Dicarboxylic acid complex salt>
Among the specific compounds, the dicarboxylic acid complex salt is not particularly limited, and any dicarboxylic acid complex salt can be used.
Examples of dicarboxylic acid complex salts include dicarboxylic acid complex salts in which the complex center element is boron.
Examples thereof include a dicarboxylic acid complex salt in which the complex central element is phosphorus.

Specific examples of the dicarboxylic acid complex salt in which the central element of the complex is boron include lithium bis (oxalate) borate, lithium difluoro (oxalat) borate, lithium bis (malonato) borate, lithium difluoro (malonato) borate, and lithium bis (methylmalonato). Examples thereof include borate, lithium difluoro (methylmaronato) borate, lithium bis (dimethylmaronato) borate, and lithium difluoro (dimethylmaronato) borate.

Specific examples of the dicarboxylic acid complex salt in which the central element of the complex is phosphorus include lithium tris (oxalat) phosphate, lithium difluorobis (oxalat) phosphate, lithium tetrafluoro (oxalat) phosphate, lithium tris (malonato) phosphate, and lithium difluorobis. (Maronato) Phosphate, Lithium Tetrafluoro (Maronato) Phosphate, Lithium Tris (Methyl Maronato) Phosphate, Lithium Difluorobis (Methyl Maronato) Phosphate, Lithium Tetrafluoro (Methyl Maronato)
Phosphate, Lithium Tris (Dimethylmalonato) Phosphate, Lithium Difluorobis (Dimethylmalonato) Phosphate, Lithium Tetrafluoro (Dimethylmalonato)
Phosphate and the like can be mentioned.

Among them, lithium bis (oxalate) oxalate, lithium difluoro (oxalate) oxalate, lithium tris (oxalate) oxalate, lithium difluorobis (oxalate) oxalate, and lithium tetrafluoro (oxalate) oxalate are easily available and have a stable film-like structure. It is more preferably used because it can contribute to the formation of an object.

The content of the dicarboxylic acid complex salt is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired, but is preferably 0.001% by mass or more with respect to the non-aqueous electrolyte solution of the present invention.
.. It is 5% by mass or less.
When the content of the dicarboxylic acid complex salt is at least this lower limit, it is possible to bring about a sufficient effect of improving the cycle characteristics in the non-aqueous electrolyte secondary battery. Further, when it is not more than this upper limit, it is possible to avoid an increase in the manufacturing cost of the non-aqueous electrolyte secondary battery, and it is possible to avoid volume expansion of the non-aqueous electrolyte secondary battery due to gas generation. The content of the dicarboxylic acid complex salt is more preferably 0.01% by mass or more, further preferably 0.1% by mass or more, and particularly preferably 0.2.
It is mass% or more, more preferably 5.0 mass% or less, still more preferably 3.0 mass% or less, and particularly preferably 2.0 mass% or less.

<2-9. Preferred specific compound>
Examples of the particular compound, a cyclic carbonate having a fluorine atom, a carbon - cyclic carbonate having a carbon-carbon unsaturated bond, difluorophosphate, salts having a FSO ₂ structure, a compound having an isocyanato group, cyclic sulfonic acid esters and dicarboxylic acid complexes preferably contains at least one compound selected from salts, among others, carbon - and more preferably contains a salt having a cyclic carbonate, difluorophosphate or FSO ₂ structure having a carbon-carbon unsaturated bond. Specific specific compounds include monofluoroethylene carbonate, 4,
4-Difluoroethylene carbonate, 4,5-difluoroethylene carbonate, vinylene carbonate, vinylethylene carbonate, ethynylethylene carbonate, lithium difluorophosphate, lithium fluorosulfonate, (FSO ₂ ) ₂ NLi, 1,6-
Diisocyanatohexane, 1,3-bis (isocyanatomethyl) cyclohexane, 1,3
-Propane sultone, methylenemethane disulfonate, 1-propene-1,3-sultone, lithium bis (oxalate) borate, lithium difluoro (oxalate) borate,
It preferably contains lithium tris (oxalate) phosphate, lithium difluorobis (oxalate) phosphate or lithium tetrafluoro (oxalat) phosphate, and preferably contains monofluoroethylene carbonate, vinylene carbonate, vinylethylene carbonate, lithium difluorophosphate, lithium fluorosulfonate. , (FSO ₂ ) ₂
NLi, 1,6-diisocyanatohexane, 1,3-bis (isocyanatomethyl) cyclohexane, 1,3-propanesultone, methylenemethanedisulfonate, 1-propene-
More preferably, it contains 1,3-sultone, lithium bis (oxalate) borate, lithium difluoro (oxalate) borate or lithium difluorobis (oxalate) phosphate.
It is also preferable to contain a plurality of of the above-mentioned specific compounds, and it is more preferable to contain both a cyclic carbonate having a carbon-carbon unsaturated bond and a difluorophosphate.

<3. Non-aqueous electrolyte>
<3-1. Electrolyte>
The non-aqueous electrolyte solution in the present invention usually contains an electrolyte as a component thereof, like a general non-aqueous electrolyte solution. The electrolyte preferably contains at least one lithium salt.
The lithium salt is not particularly limited as long as it is known to be used as an electrolyte, and any lithium salt can be used, and specific examples thereof include the following.

For example
LiBF ₄ , LiClO ₄ , LiAlF ₄ , LiPF ₆ , LiSbF ₆ , LiTaF ₆
, LiWOF ₅ , LiWF _{7, and} other inorganic lithium halogenated salts;
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
Lithium carboxylic acid salts such as O ₂ Li, CF ₃ CF ₂ CF ₂ CF ₂ CO ₂ Li;
CH ₃ SO ₃ Li, CH ₂ FSO ₃ Li, CHF ₂ SO ₃ Li, CF ₃ SO ₃ Li, C
F ₃ CF ₂ SO ₃ Li, CF ₃ CF ₂ CF ₂ SO ₃ Li, CF ₃ CF ₂ CF ₂ CF ₂ SO
₃ sulfonic acid lithium salts other than _FSO 3 Li, such as Li;
Lithium methylsulfate, lithium ethylsulfate, lithium 2-propynylsulfate, lithium 1-methyl-2-propynylsulfate, 1,1-dimethyl-2-propynylsulfate, 2,
Lithium sulfate salts such as 2,2-trifluoroethyl lithium sulfate and dilithium ethylene disulfate;
LiN (FCO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , Lithium cyclic 1,2-perfluoroethanedisulfonylimide, Lithium cyclic 1,3-perfluoropropanedi Lithium imide salts other than salts having an FSO ₂ structure such as sulfonylimide and LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ );
Lithiummethide salts such as LiC (FSO ₂ ) ₃ , LiC (CF ₃ SO ₂ ) ₃ , LiC (C ₂ F ₅ SO ₂ ) ₃ ;
Lithium oxalate salts such as lithium difluorooxalatoborate, lithium tetrafluorooxalat phosphate, lithium tris (oxalate) 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 organolithium salts such as (CF ₃ SO ₂ ) ₂ , LiBF ₂ (C ₂ F ₅ SO ₂ ) ₂ ;
And so on.

Among these lithium salts, inorganic lithium salts and lithium sulfonic acid salts are used from the viewpoint of further enhancing the input / output characteristics after durability tests such as high temperature storage test and cycle test, charge / discharge rate charge / discharge characteristics, and impedance characteristics. , Lithiumimide salts and lithium oxalate salts are preferable.
Among them, LiBF ₄ , LiPF ₆ , LiSbF ₆ , LiTaF ₆ , CF ₃ SO ₃ Li,
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. The} effect of lithium difluorooxalatoborate, lithium tetrafluorooxarat phosphate and lithium tris (oxalate) phosphate to improve input / output characteristics, high-rate charge / discharge characteristics, impedance characteristics, high-temperature storage characteristics, cycle characteristics, etc. It is particularly preferable because there is a certain point.

The total concentration of these electrolytes in the non-aqueous electrolyte solution is not particularly limited, but when the total concentration of the non-aqueous electrolyte solution is 100% by mass, it is usually 8% by mass or more, preferably 8.5% by mass or more, more preferably. Is 9% by mass or more. The upper limit is usually 18% by mass or less, preferably 17% by mass.
Hereinafter, it is more preferably 16% by mass or less. When the total concentration of the electrolyte is within the above range, the electric conductivity is preferable because the battery operation is appropriate.

In addition, these electrolytes may be used alone, in combination of two or more, or in combination with a specific compound. Preferred examples of the combined use are LiPF ₆ and LiBF ₄ , LiPF ₆ and L.
iPO ₂ F ₂ , LiPF ₆ and FSO ₃ Li, LiPF ₆ and LiN (FSO ₂ ) ₂ , LiP
F ₆ and LiN (CF ₃ SO ₂ ) ₂ , LiPF ₆ and lithium bis (oxalate) borate,
LiPF ₆ and Lithium Tetrafluorooxalat Phosphate, LiPF ₆ and Lithium Difluorobis (Oxalato) Phosphate, LiPF ₆ and LiBF ₄ and LiPO ₂ F
₂ , LiPF ₆ and LiBF ₄ and FSO ₃ Li, LiPF ₆ and LiPO ₂ F ₂ and FSO ₃ L
i, LiPF ₆ and LiPO ₂ F ₂ and Lithium Bis (Oxalato) Borate, LiPF ₆ and LiPO ₂ F ₂ and Lithium Difluorobis (Oxalato) Phosphate, LiPF ₆ and LiPO ₂ F ₂ and LiN (FSO ₂ ) ₂ , LiPF ₆ and LiPO ₂ F ₂ and LiN (CF ₃₎
SO ₂ ) ₂ , LiPF ₆ and FSO ₃ Li and lithium bis (oxalate) borate, or L
The combined use of iPF ₆ and FSO ₃ Li and lithium difluorobis (oxalate) phosphate has the effect of improving input / output characteristics, high temperature storage characteristics, and cycle characteristics. in this case,
The content of LiPF ₆ is preferably 7% by mass or more, more preferably 7. in a non-aqueous electrolyte solution.
It is 5% by mass or more, more preferably 8% by mass or more, preferably 16% by mass or less, more preferably 15% by mass or less, still more preferably 14% by mass or less, and LiBF ₄ , LiPO ₂
F ₂ , FSO ₃ Li, LiN (FSO ₂ ) ₂ LiN (CF ₃ SO ₂ ) ₂ , Lithium screw (
The content of oxalate) borate or lithium difluorobis (oxalate) phosphate is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.1% by mass in the non-aqueous electrolyte solution. % Or more, preferably 5% by mass or less, more preferably 4
It is mass% or less, more preferably 3 mass% or less. When the concentration of LiPF ₆ is within the above-mentioned preferable range, the total ion content and the viscosity in the non-aqueous electrolyte solution are in an appropriate balance, so that the internal impedance of the battery is lowered without excessively lowering the ionic conductivity. The effect of improving the input / output characteristics, cycle characteristics, and storage characteristics by blending LiPF ₆ is more likely to be exhibited.

Here, the non-aqueous electrolyte solution containing the above electrolyte material may be prepared by a known method.
Not particularly limited. For example, a method of adding the separately synthesized electrolyte material to a non-aqueous electrolyte solution, or mixing the electrolyte material with a battery component such as an active material or a electrode plate described later to construct a battery element (battery element). When assembling a battery by injecting a non-aqueous electrolyte solution, the above electrolyte material is dissolved in the non-aqueous electrolyte solution, and water is allowed to coexist in the battery components such as the active material, the electrode plate, and the separator. Examples thereof include a method of generating another electrolyte material in the system when assembling a non-aqueous electrolyte secondary battery using the non-aqueous electrolyte solution containing the above electrolyte material. In the present invention, any method may be used.

The method for measuring the content of each electrolyte in the above-mentioned non-aqueous electrolyte solution and non-aqueous electrolyte solution secondary battery is not particularly limited, and any known method can be used. Specifically, and ion chromatography, ^{19 F} nuclear magnetic resonance spectroscopy (hereinafter, sometimes referred to as "NMR".), And the like.

<3-2. Non-aqueous solvent>
Like a general non-aqueous electrolyte solution, the non-aqueous electrolyte solution according to an embodiment of the present invention usually contains a non-aqueous solvent that dissolves the above-mentioned electrolyte as its main component. The non-aqueous solvent used here is not particularly limited, and a known organic solvent can be used. The organic solvent preferably contains at least one organic solvent selected from the group consisting of saturated cyclic carbonates, chain carbonates, chain carboxylic acid esters, cyclic carboxylic acid esters, ether compounds and sulfone compounds. , These are not particularly limited. These can be used alone or in combination of two or more.
Further, in one embodiment of the present invention, it is preferable that the non-aqueous electrolyte solution contains at least one of the group consisting of cyclic carbonate, chain carbonate, and chain ester.

<3-2-1. Saturated cyclic carbonate>
Examples of the saturated cyclic carbonate include those having an alkylene group having 2 to 4 carbon atoms.
Specifically, as the saturated cyclic carbonate having 2 to 4 carbon atoms, ethylene carbonate,
Examples thereof include propylene carbonate and butylene carbonate. Of these, ethylene carbonate and propylene carbonate are preferable from the viewpoint of improving battery characteristics resulting from an improvement in the degree of lithium ion dissociation. As the saturated cyclic carbonate, one kind may be used alone, or two or more kinds may be used in any combination and ratio.

The content of the saturated cyclic carbonate is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but the lower limit of the content when one of them is used alone is usually in 100% by volume of a non-aqueous solvent. It is 3% by volume or more, preferably 5% by volume or more. By setting it within this range, the decrease in electrical conductivity due to the decrease in the dielectric constant of the non-aqueous electrolyte solution is avoided, and the large current discharge characteristics, stability with respect to the negative electrode, and cycle characteristics of the non-aqueous electrolyte secondary battery are improved. It will be easier to set the range. The upper limit is usually 90% by volume or less, preferably 85% by volume or less, and more preferably 80% by volume or less. By setting this range, the viscosity of the non-aqueous electrolyte solution can be set to an appropriate range, the decrease in ionic conductivity can be suppressed, and the input / output characteristics of the non-aqueous electrolyte secondary battery can be further improved, and the cycle characteristics and storage can be achieved. Durability such as characteristics can be further improved, which is preferable.

Further, the saturated cyclic carbonate can be used in any combination of two or more kinds.
One of the preferred combinations is a combination of ethylene carbonate and propylene carbonate. The volume ratio of ethylene carbonate to propylene carbonate in this case is 99:
It is preferably 1 to 40:60, more preferably 95: 5 to 50:50. Further, the lower limit of the amount of propylene carbonate in the whole non-aqueous solvent is usually 1% by volume or more, preferably 2% by volume or more, and more preferably 3% by volume or more. The upper limit is usually 30% by volume.
Hereinafter, it is preferably 25% by volume or less, more preferably 20% by volume or less. It is preferable to contain propylene carbonate in this range because the low temperature characteristics are further excellent.

<3-2-2. Chain carbonate>
The chain carbonate preferably has 3 to 7 carbon atoms.
Specifically, the chain carbonate having 3 to 7 carbon atoms includes dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, and n-.
Propyl isopropyl carbonate, ethyl methyl carbonate, methyl-n-propyl carbonate, n-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 can be mentioned.

Of these, dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propylisopropyl carbonate, ethylmethyl carbonate or methyl-n-propyl carbonate are preferable, and dimethyl carbonate, diethyl carbonate or ethylmethyl carbonate are particularly preferable. is there.
In addition, chain carbonates having a fluorine atom (hereinafter, "fluorinated chain carbonate")
May be abbreviated as. ) Can also be preferably 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 different carbons. Examples of the fluorinated chain carbonate include a fluorinated dimethyl carbonate derivative, a fluorinated ethyl methyl carbonate derivative, and a fluorinated diethyl carbonate derivative.

As the fluorinated dimethyl carbonate derivative, fluoromethylmethyl carbonate,
Difluoromethylmethyl carbonate, trifluoromethylmethyl carbonate, bis (
Examples thereof include fluoromethyl) carbonate, bis (difluoro) methyl carbonate, and bis (trifluoromethyl) carbonate.
Examples of the fluorinated ethyl methyl carbonate derivative include 2-fluoroethyl methyl carbonate, ethyl fluoromethyl carbonate, 2,2-difluoroethyl methyl carbonate, 2-fluoroethyl fluoromethyl carbonate, ethyl difluoromethyl carbonate, and 2,2,2-tri. Examples thereof include fluoroethyl methyl carbonate, 2,2-difluoroethyl fluoromethyl carbonate, 2-fluoroethyl difluoromethyl carbonate, ethyl trifluoromethyl carbonate and the like.

Examples of the fluorinated diethyl carbonate derivative include ethyl- (2-fluoroethyl) carbonate, ethyl- (2,2-difluoroethyl) carbonate, bis (2-fluoroethyl) carbonate, and ethyl- (2,2,2-trifluoro). Ethyl) carbonate, 2,
2-Difluoroethyl-2'-fluoroethyl carbonate, bis (2,2-difluoroethyl) carbonate, 2,2,2-trifluoroethyl-2'-fluoroethyl carbonate, 2,2,2-trifluoroethyl- Examples thereof include 2', 2'-difluoroethyl carbonate and bis (2,2,2-trifluoroethyl) carbonate.

As the chain carbonate, one type may be used alone, or two or more types may be used in combination in any combination and ratio.
The content of the chain carbonate is not particularly limited, but is usually 15 in 100% by volume of the non-aqueous solvent.
It is 50% by volume or more, preferably 20% by volume or more, and more preferably 25% by volume or more.
Further, it is usually 90% by volume or less, preferably 85% by volume or less, and more preferably 80% by volume or less. By setting the content of the chain carbonate in the above range, the viscosity of the non-aqueous electrolyte solution is set in the appropriate range, the decrease in ionic conductivity is suppressed, and the input / output characteristics and charging / discharging of the non-aqueous electrolyte secondary battery are suppressed. It is easy to set the rate characteristics in a good range. In addition, it is easy to avoid a decrease in electrical conductivity due to a decrease in the dielectric constant of the non-aqueous electrolyte solution, and to easily set the input / output characteristics and charge / discharge rate characteristics of the non-aqueous electrolyte secondary battery in a good range.

Further, by combining ethylene carbonate with a specific chain carbonate in a specific content, the battery performance can be remarkably improved.
For example, when dimethyl carbonate and ethyl methyl carbonate are selected as specific chain carbonates, the content of ethylene carbonate is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 15% by volume or more. It is preferably 20% by volume, usually 45% by volume or less, preferably 40% by volume or less, and the content of dimethyl carbonate is usually 20% by volume or more, preferably 30% by volume or more, and usually 50% by volume or less. It is preferably 45% by volume or less, and the content of ethylmethyl carbonate is usually 20% by volume or more, preferably 30% by volume or more, and usually 50% by volume or less, preferably 45% by volume or less. By setting the content within the above range, while lowering the low-temperature precipitation temperature of the electrolyte, the viscosity of the non-aqueous electrolyte solution is also lowered to improve the ionic conductivity, and high input / output can be obtained even at low temperatures.

<3-2-3. Chain carboxylic acid ester>
Examples of the chain carboxylic acid ester include those having a total carbon number of 3 to 7 in the structural formula.
Specifically, methyl acetate, ethyl acetate, -n-propyl acetate, isopropyl acetate, -n-butyl acetate, isobutyl acetate, -t-butyl acetate, methyl propionate, ethyl propionate, -n-propyl propionate, Isopropyl propionate, propionic acid -n-
Examples thereof include butyl, isobutyl propionate, -t-butyl propionate, methyl butyrate, ethyl butyrate, -n-propyl butyrate, isopropyl butyrate, methyl isobutyrate, ethyl isobutyrate, -n-propyl isobutyric acid, and isopropyl isobutyrate. ..

Among them, methyl acetate, ethyl acetate, -n-propyl acetate, -n-butyl acetate, methyl propionate, ethyl propionate, -n-propyl propionate, isopropyl propionate, methyl butyrate or ethyl butyrate are ions due to a decrease in viscosity. It is preferable from the viewpoint of improving conductivity and suppressing battery swelling during durability such as cycle and storage.
The content of the chain carboxylic acid ester is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 5% by volume or more, preferably 8% by volume in 100% by volume of the non-aqueous solvent.
It is usually 80% by volume or less, preferably 70% by volume or less. When the content of the chain carboxylic acid ester is within the above range, the electric conductivity of the non-aqueous electrolyte solution is improved, and the input / output characteristics and charge / discharge rate characteristics of the non-aqueous electrolyte secondary battery can be easily improved. In addition, the increase in negative electrode resistance is suppressed, and the input / output characteristics and charge / discharge rate characteristics of the non-aqueous electrolyte secondary battery can be easily set in a good range.

When a chain carboxylic acid ester is used, it is preferably used in combination with a cyclic carbonate, and more preferably a combination of a cyclic carbonate and a chain carbonate.
For example, when the cyclic carbonate and the chain carboxylic acid ester are used in combination, the content of the cyclic carbonate is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 15% by volume or more, preferably 20. By volume%, usually 45% by volume or less, preferably 40% by volume or less, and the content of the chain carboxylic acid ester is usually 20% by volume or more, preferably 30% by volume or more, and usually 55% by volume or less, preferably 55% by volume or less. Is 50% by volume or less. When the cyclic carbonate, the chain carbonate, and the chain carboxylic acid ester are used in combination, the content of the cyclic carbonate is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 15% by volume or more. It is preferably 20% by volume, usually 45% by volume or less, preferably 40% by volume or less, and the content of the chain carbonate is usually 25% by volume or more, preferably 30% by volume or more, and usually 84% by volume or less. , Preferably 80% by volume or less. By setting the content within the above range, it is possible to reduce the low-temperature precipitation temperature of the electrolyte, reduce the viscosity of the non-aqueous electrolyte solution, improve the ionic conductivity, and obtain even higher input / output even at low temperatures. It is also preferable from the viewpoint of further reducing battery swelling.

<3-2-4. Cyclic carboxylic acid ester>
Examples of the cyclic carboxylic acid ester include those having a total carbon atom number of 3 to 12 in the structural formula.
Specifically, gamma-butyrolactone, gamma valerolactone, gamma caprolactone,
Epsilon caprolactone and the like can be mentioned. Of these, gamma-butyrolactone is particularly preferable from the viewpoint of improving battery characteristics resulting from an improvement in the degree of lithium ion dissociation.

The content of the cyclic carboxylic acid ester is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 3% by volume or more, preferably 5% by volume in 100% by volume of the non-aqueous solvent.
It is usually 60% by volume or less, preferably 50% by volume or less. When the content of the cyclic carboxylic acid ester is within the above range, the electric conductivity of the non-aqueous electrolyte solution is improved, and the input / output characteristics and charge / discharge rate characteristics of the non-aqueous electrolyte secondary battery can be easily improved. In addition, the viscosity of the non-aqueous electrolyte is set to an appropriate range, the decrease in electrical conductivity is avoided, the increase in negative electrode resistance is suppressed, and the input / output characteristics and charge / discharge rate characteristics of the non-aqueous electrolyte secondary battery are in a good range. It becomes easy to do.

<3-2-5. Ether compounds>
As the ether compound, a chain ether having 3 to 10 carbon atoms and a cyclic ether having 3 to 6 carbon atoms are preferable.
Examples of the chain ether having 3 to 10 carbon atoms include diethyl ether, di (2-fluoroethyl) ether, di (2,2-difluoroethyl) ether, di (2,2,2-trifluoroethyl) ether, and 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-tetrafluoro) Ethyl) 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) 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-tetrafluoroethyl) (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-pentafluoro-n-propyl) ether, di-n-propyl ether , (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)
3-Pentafluoro-n-propyl) ether, di-n-butyl ether, 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) methanedi (2,2,2-trifluoroethoxy) methane, (2,2,2-trifluoroethoxy) (1,1,2,2-tetrafluoroethoxy) methane, di (1,1,2,2-tetrafluoroethoxy) methane, dimethoxyethane, methoxyethoxyethane, methoxy (2-fluoroethoxy) ethane, methoxy (2,2)
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, Examples thereof include di (1,1,2,2-tetrafluoroethoxy) ethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, diethylene glycol dimethyl ether and the like.

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, and 1 , 4-Dioxane and the like, and fluorinated compounds thereof.
Among these, dimethoxymethane, diethoxymethane, ethoxymethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether or diethylene glycol dimethyl ether have high solvation ability to lithium ions and have ionic dissociability. It is preferable in terms of improvement. Particularly preferred is dimethoxymethane, diethoxymethane or ethoxymethoxymethane because of its low viscosity and high ionic conductivity.

The content of the ether compound is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 1% by volume or more, preferably 2% by volume or more in 100% by volume of the non-aqueous solvent.
More preferably 3% by volume or more, and usually 30% by volume or less, preferably 25% by volume or less,
More preferably, it is 20% by volume or less. When the content of the ether-based compound is within the above-mentioned preferable range, it is easy to secure the effect of improving the lithium ion dissociation degree of the chain ether and improving the ionic conductivity resulting from the decrease in viscosity. Further, when the negative electrode active material is a carbonaceous material, the phenomenon that the chain ether is co-inserted together with the lithium ions can be suppressed, so that the input / output characteristics and the charge / discharge rate characteristics can be set in an appropriate range.

<3-2-6. Sulfone compounds>
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.
Examples of the cyclic sulfone include trimethylene sulfones, tetramethylene sulfones, and hexamethylene sulfones, which are monosulfone compounds; and trimethylene disulfones, tetramethylene disulfones, and hexamethylene disulfones, which are disulfone compounds. Among them, tetramethylene sulfones, tetramethylene disulfones, hexamethylene sulfones or hexamethylene disulfones are more preferable, and tetramethylene sulfones (sulfolanes) are particularly preferable, from the viewpoint of dielectric constant and viscosity.

As the sulfolanes, sulfolanes and / or sulfolane derivatives (hereinafter, sulfolanes may be abbreviated as "sulfolanes") are preferable. The sulfolane derivative is preferably one in which one or more hydrogen atoms bonded on the carbon atom 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-methylsulfolane, 4-fluoro-2-methylsulfolane, 5-fluoro-3-methylsulfolane, 5-fluoro-2-methylsulfolane, 2-fluoromethylsulfolane, 3-fluoromethylsulfolane, 2-difluoromethyl Sulfolane, 3-difluoromethyl sulfolane, 2-trifluoromethyl sulfolane, 3-trifluoromethyl sulfolane, 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 because they have high ionic conductivity and high input / output.

Examples of the chain sulfone include dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl methyl sulfone, n-propyl ethyl sulfone, di-n-propyl sulfone, isopropyl methyl sulfone, isopropyl ethyl sulfone, diisopropyl sulfone, and n-. Butylmethylsulfone, n-butylethylsulfone, t-butylmethylsulfone, t-butylethylsulfone, monofluoromethylmethylsulfone, difluoromethylmethylsulfone, trifluoromethylmethylsulfone, monofluoroethylmethylsulfone, difluoroethylmethylsulfone, Trifluoroethyl methyl sulfone, pentafluoroethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, ethyl trifluoromethyl sulfone, perfluoroethyl methyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoroethyl sulfone, di (tri) Fluoroethyl) sulfone, perfluorodiethyl sulfone, fluoromethyl-n-propyl sulfone, difluoromethyl-n-propyl sulfone, trifluoromethyl-n-
Propyl sulfone, fluoromethyl isopropyl sulfone, difluoromethyl isopropyl sulfone, trifluoromethyl isopropyl sulfone, trifluoroethyl-n-propyl sulfone, trifluoroethyl isopropyl sulfone, pentafluoroethyl-n-
Propyl sulfone, pentafluoroethyl isopropyl sulfone, trifluoroethyl-
Examples thereof include n-butyl sulfone, trifluoroethyl-t-butyl sulfone, pentafluoroethyl-n-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, trifluoroethyl-n-butyl sulfone, trifluoroethyl-t-butyl sulfone, trifluoromethyl-n-butyl sulfone or trifluoromethyl-t -Butyl sulfone is preferable because it has high ionic conductivity and high input / output.

The content of the sulfone compound is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.3% by volume or more, preferably 0.5% by volume in 100% by volume of the non-aqueous solvent. Above, more preferably 1% by volume or more, and usually 40% by volume or less, preferably 3
It is 5% by volume or less, more preferably 30% by volume or less. When the content of the sulfone compound is within the above range, it is easy to obtain the effect of improving durability such as cycle characteristics and storage characteristics, and also
The viscosity of the non-aqueous electrolyte solution can be set in an appropriate range to avoid a decrease in electrical conductivity, and the input / output characteristics and charge / discharge rate characteristics of the non-aqueous electrolyte secondary battery can be set in an appropriate range.

<3-3. Auxiliary agent>
The non-aqueous electrolyte solution of the present invention may further contain various auxiliaries described in detail below.
<3-3-1. Overcharge inhibitor ＞
Specific examples of the overcharge inhibitor include toluene derivatives such as toluene, xylene, 2-fluorotoluene, 3-fluorotoluene, and 4-fluorotoluene;
Biphenyl derivatives that are unsubstituted or substituted with an alkyl group such as biphenyl, 2-methylbiphenyl, 3-methylbiphenyl, 4-methylbiphenyl;
Terphenyl derivatives such as o-terphenyl, m-terphenyl, p-terphenyl, etc., which are unsubstituted or substituted with an alkyl group;
Partially hydride of terphenyl derivative unsubstituted or substituted with alkyl group;
Cycloalkylbenzene derivatives such as cyclopentylbenzene and cyclohexylbenzene;
Alkylbenzene derivatives having a tertiary carbon directly attached to the benzene ring such as cumene, 1,3-diisopropylbenzene, 1,4-diisopropylbenzene;
Alkylbenzene derivatives having a quaternary carbon that directly binds to the benzene ring such as t-butylbenzene, t-amylbenzene, t-hexylbenzene, 1,1,3-trimethyl-3-phenylindane;
Aromatic compounds with oxygen atoms such as diphenyl ether and dibenzofuran;
Aromatic compounds such as.

Further, specific examples of other overcharge inhibitors include partially fluorinated compounds of the aromatic compounds such as fluorobenzene, benzotrifluoride, 2-fluorobiphenyl, o-cyclohexylfluorobenzene and p-cyclohexylfluorobenzene; Fluoro-containing anisole compounds such as 4-difluoroanisole, 2,5-difluoroanisole and 1,6-difluoroanisole; and the like can also be mentioned.

One of these overcharge inhibitors may be used alone, or two or more of them may be used in any combination and ratio. Further, when used in any combination, the compounds of the same classification exemplified above may be used in combination, or the compounds of different classifications may be used in combination.
When the overcharge inhibitor is blended, the blending amount of the overcharge inhibitor is arbitrary as long as the effect of the present invention is not significantly impaired, but is preferably 0. 0
The range is 01% by mass or more and 10% by mass or less.

By containing an overcharge inhibitor in the non-aqueous electrolyte solution of the present invention within a range that does not significantly impair the effects of the present invention, the overcharge protection circuit such as incorrect usage or abnormality of the charging device operates normally. It is preferable because the safety of the energy device can be improved so that there is no problem even if the energy device is overcharged in a non-existing situation.

<3-3-2. Other auxiliaries>
Specific examples of other auxiliaries for improving capacity retention characteristics and cycle characteristics after high-temperature storage include the following.
Carbonate compounds other than those corresponding to unsaturated bonds such as erythritan carbonate and spiro-bis-dimethylene carbonate;
Cyclic sulfite such as ethylene sulfite;
Non-fluorinated cyclic sulfate esters such as ethylene sulfate, vinylene sulfate, and propylene sulfate;
Chain sulfonic acid esters such as methyl methanesulfonate and busulfan;
Cyclic sulfones such as sulfolanes and sulfolene;
Chain sulfone such as dimethyl sulfone, diphenyl sulfone, methyl phenyl sulfone;
Sulfides such as dibutyl disulfide, dicyclohexyl disulfide, tetramethylthiuram monosulfide;

Sulfur-containing compounds such as sulfonamides such as N, N-dimethylmethanesulfonamide and N, N-diethylmethanesulfonamide;
Nitrogen-containing compounds such as 1-methyl-2-pyrrolidinone, 1-methyl-2-piperidone, 3-methyl-2-oxazolidinone, 1,3-dimethyl-2-imidazolidinone;
Hydrocarbon compounds such as heptane, octane and cycloheptane;
2- (Diethoxyphosphoryl) propargyl acetate, 2- (diethoxyphosphoryl) 2-butynyl acetate, 2- (methanesulfonyloxy) propargyl propionate, propargyl methanesulfonyloxyacetate, lithium ethyl-propargyloxycarbonylphosphonate, lithium ethyl- 2-butynyloxycarbonylphosphonate, propargyl lithium sulfate, 2-butynyl lithium sulfate, propargyltrimethylsilyl sulfate, 2-
Butin-1,4-diyl dimesylate, 2-butyne-1,4-diyldiethanesulfonate, 2-butyne-1,4-diyldiformate, 2-butyne-1,4-diyldiacetate, 2-butyne-1 , 4-Diyl Dipropionate, 4-Hexadiin-1,
6-Diyl dimethanesulfonate, propargyl methanesulfonate, 2-butynyl methanesulfonate, propargyl ethanesulfonic acid, propargyl vinylsulfonate, propargyl methyl carbonate, propargyl ethyl carbonate, dipropargyl carbonate, propargyl formate, propargyl acetate, methacrylic acid Triple-binding compounds such as propargyl, methylpropargyl oxalate, ethylpropargyl oxalate, dipropargyl oxalate;

Tris borate (trimethylsilyl), tris borate (trimethoxysilyl), tris phosphate (trimethylsilyl), tris phosphate (trimethoxysilyl), dimethoxyaluminoxytrimethoxysilane, diethoxyaluminoxytriethoxysilane, dipropoxyalumino Silane compounds such as xitriethoxysilane, dibutoxyaluminoxytrimethoxysilane, dibutoxyaluminoxytriethoxysilane, titaniumtetrakis (trimethylsiloxide), and titaniumtetrakis (triethylsiloxide);
Fluoro-containing aromatic compounds such as fluorobenzene, difluorobenzene and benzotrifluoride;
Pentafluorophenyl compounds such as pentafluorophenyl methanesulfonate, pentafluorophenyl trifluoromethanesulfonate, pentafluorophenyl acetate, pentafluorophenyl trifluoroacetate, and methylpentafluorophenyl carbonate.

As these other auxiliaries, one type may be used alone, or two or more types may be used in combination in any combination and ratio.
When the non-aqueous electrolyte solution of the present invention contains these other auxiliaries, the content thereof is arbitrary as long as the effect of the present invention is not significantly impaired, but the entire non-aqueous electrolyte solution (100% by mass). On the other hand, it is preferably in the range of 0.001% by mass or more and 10% by mass or less.

The non-aqueous electrolyte solution described above also includes those existing inside an energy device such as a non-aqueous electrolyte secondary battery according to an embodiment of the present invention. Specifically, the components of the non-aqueous electrolyte solution such as lithium salt, solvent, and auxiliary agent are separately synthesized, the non-aqueous electrolyte solution is prepared from the substantially isolated one, and the method described below is used. Non-aqueous electrolyte solution obtained by injecting liquid into a separately assembled battery When it is a non-aqueous electrolyte solution in a secondary battery, or when the components of the non-aqueous electrolyte solution of the present invention are individually put in a battery, When the same composition as the non-aqueous electrolyte solution of the present invention is obtained by mixing in the non-aqueous electrolyte secondary battery, the compound constituting the non-aqueous electrolyte solution of the present invention is further added to the non-aqueous electrolyte secondary battery. It is also included in the case where it is generated inside to obtain the same composition as the non-aqueous electrolyte solution of the present invention.

<3-4. Manufacturing method of non-aqueous electrolyte solution>
The non-aqueous electrolyte solution of the present invention dissolves an electrolyte, a compound represented by the general formula (1), a specific compound, and, if necessary, the above-mentioned "auxiliary agent" in the above-mentioned non-aqueous solvent. Can be prepared by.
When preparing a non-aqueous electrolyte solution, each raw material of the non-aqueous electrolyte solution, that is, an electrolyte such as a lithium salt, a compound represented by the general formula (1), a specific compound, a non-aqueous solvent, an auxiliary agent, etc. is previously prepared. It is preferable to dehydrate. The degree of dehydration is usually 50 ppm or less, preferably 30 p.
It is desirable to dehydrate until it is pm or less.

By removing the water in the non-aqueous electrolyte solution, the electrolysis of water, the reaction between water and lithium metal,
Hydrolysis of lithium salt is less likely to occur. The means for dehydration is not particularly limited, but for example, when the object to be dehydrated is a liquid such as a non-aqueous solvent, a desiccant such as molecular sieve may be used. When the object to be dehydrated is a solid such as an electrolyte, it may be heated and dried at a temperature lower than the temperature at which decomposition occurs.

<4. Energy device using non-aqueous electrolyte solution>
The energy device using the non-aqueous electrolyte solution of the present invention includes a plurality of electrodes capable of storing or releasing metal ions, and the non-aqueous electrolyte solution of the present invention described above. Specific examples of the types of energy devices include metal ion capacitors such as primary batteries, secondary batteries, and lithium ion capacitors. Among them, a primary battery or a secondary battery is preferable, and a secondary battery is particularly preferable. It is also preferable that the non-aqueous electrolyte solution used for these energy devices is a so-called gel electrolyte that is pseudo-solidified with a polymer, a filler, or the like. Hereinafter, the energy device will be described.

<4-1. Non-aqueous electrolyte secondary battery ＞
<4-1-1. Battery configuration>
The non-aqueous electrolyte secondary battery (hereinafter, also referred to as the non-aqueous secondary battery of the present invention) according to the embodiment of the present invention has a conventionally known non-aqueous electrolyte secondary battery having a configuration other than the non-aqueous electrolyte solution. Similar to the next battery, usually, the positive electrode and the negative electrode are laminated via a porous film (separator) impregnated with the non-aqueous electrolyte solution of the present invention, and these are housed in a case (exterior body). Has. Therefore, the shape of the non-aqueous electrolyte secondary battery of the present invention is not particularly limited, and may be any of a cylindrical type, a square type, a laminated type, a coin type, a large size, and the like.

<4-1-2. Non-aqueous electrolyte>
As the non-aqueous electrolyte solution, the above-mentioned non-aqueous electrolyte solution of the present invention is used. It is also possible to mix other non-aqueous electrolyte solutions with the non-aqueous electrolyte solution of the present invention without departing from the spirit of the present invention.

<4-1-3. Negative electrode ＞
The negative electrode active material used for the negative electrode is not particularly limited as long as it can electrochemically occlude and release metal ions. Specific examples thereof include carbonaceous materials, metal compound materials, lithium-containing metal composite oxide materials, and the like. One of these may be used alone, or two or more thereof may be used in combination.
Of these, carbonaceous materials and metal compound materials are preferable. Among metal compound materials,
A material containing silicon is preferable, and therefore, as the negative electrode active material, a carbonaceous material and a material containing silicon are particularly preferable.

<4-1-3-1. Carbonaceous material>
The carbonaceous material used as the negative electrode active material is not particularly limited, but the following (a) to
The one selected from (d) is preferable because it provides a secondary battery having a good balance of initial irreversible capacity and high current density charge / discharge characteristics.
(A) Natural graphite (B) Carbonaceous material obtained by heat-treating artificial carbonaceous material and artificial graphite material at least once in the range of 400 ° C to 3200 ° C (c) At least two types of negative electrode active material layers Consisting of carbonaceous materials with different crystallinity,
And / or a carbonaceous material having an interface in which different crystalline carbonaceous materials are in contact with each other (d) The negative electrode active material layer is composed of at least two kinds of carbonaceous materials having different orientations.
And / or carbonaceous materials having an interface in which carbonaceous materials having different orientations are in contact with each other. As the carbonaceous materials (a) to (d), one type may be used alone, or two or more types may be used in any combination. And may be used in combination.

Specific examples of the artificial carbonaceous substance or the artificial graphite substance in (a) above include natural graphite.
Coal-based coke, petroleum-based coke, coal-based pitch, petroleum-based pitch, and oxidation-treated pitches;
Needle coke, pitch coke and partially graphitized carbon material;
Thermal decomposition products of organic substances such as furnace black, acetylene black, and pitch-based carbon fibers;
Carbideable organics and their carbides;
Examples thereof include solution-like carbides in which a carbonizable organic substance is dissolved in a low-molecular-weight organic solvent such as benzene, toluene, xylene, quinoline, and n-hexane.
In addition, all of the above carbonaceous materials (a) to (d) are conventionally known, their manufacturing methods are well known to those skilled in the art, and these commercially available products can also be purchased.

<4-1-3-2. Metal compound materials>
The metal compound-based material used as the negative electrode active material is not particularly limited as long as it can occlude and release lithium, and is a simple substance or alloy that forms an alloy with lithium, or oxides, carbides, nitrides, and nitrides thereof. Compounds such as silicates, sulfides and phosphors can be used. Examples of such metal compounds include Ag, Al, Ba, Bi, Cu, Ga, Ge, In, Ni, P, and the like.
Examples thereof include compounds containing metals such as Pb, Sb, Si, Sn, Sr, and Zn. Among them, it is preferable that it is a simple substance metal or alloy forming an alloy with lithium, and the metal / metalloid element of Group 13 or 14 of the periodic table (that is, carbon is excluded. In the following, the metal and metalloid are collectively referred to as ". It is more preferably a material containing (referred to as "metal"), and further, silicon (S).
i) Elemental metals of elemental metals of tin (Sn) or lead (Pb) (hereinafter, these three elements may be referred to as "SSP metal elements"), alloys containing these atoms, or metals thereof (SSP).
It is preferably a compound of metal element). Particularly preferred are compounds containing silicon. One of these may be used alone, or two or more thereof may be used in any combination and ratio.

<4-1-3-3. Lithium-containing metal composite oxide material>
The lithium-containing metal composite oxide material used as the negative electrode active material is not particularly limited as long as it can occlude and release lithium, but a lithium-containing composite metal oxide material containing titanium is preferable, and composite oxidation of lithium and titanium is preferable. (Hereinafter, "lithium titanium composite oxide"
May be abbreviated as. ) Is particularly preferable. That is, it is particularly preferable to use a lithium titanium composite oxide having a spinel structure in a negative electrode active material for a lithium ion non-aqueous electrolyte secondary battery because the output resistance of the secondary battery is significantly reduced.

In addition, lithium and titanium of the lithium titanium composite oxide are other metal elements such as Na.
, K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and Nb, which are substituted with at least one element selected from the group.
Examples of the lithium titanium composite oxide preferable as the negative electrode active material include the lithium titanium composite oxide represented by the following general formula (7).
_{Li x Ti y M z O 4} (7)
(In the general formula (7), M is Na, K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu.
, Zn and Nb represents at least one element selected from the group. Also, the general formula (7)
), 0.7 ≦ x ≦ 1.5, 1.5 ≦ y ≦ 2.3, and 0 ≦ z ≦ 1.6 are stable structures during lithium ion doping and dedoping. Therefore, it is preferable. )

<4-1-3-4. Negative electrode configuration, physical properties, preparation method>
A known technical configuration can be adopted for the negative electrode, the electrode conversion method, and the current collector containing the active material, but any one or more of the following items (i) to (vi) are shown below. It is desirable to satisfy at the same time.

(I) Preparation of negative electrode Any known method can be used for the production of the negative electrode as long as the effect of the present invention is not significantly limited. For example, a binder, a solvent, and if necessary, a thickener, a conductive material, a filler, and the like are added to the negative electrode active material to form a slurry-like negative electrode forming material, which is applied to a current collector, dried, and then pressed. Thereby, the negative electrode active material layer can be formed.

(Ii) Current collector A known current collector can be arbitrarily used as the current collector for holding the negative electrode active material. Examples of the current collector of the negative electrode include metal materials such as aluminum, copper, nickel, stainless steel, and nickel-plated steel, but copper is particularly preferable from the viewpoint of ease of processing and cost.
When the current collector is made of a metal material, the shape of the current collector may be, for example, a metal foil, a metal column, a metal coil, a metal plate, a metal thin film, an expanded metal, a punch metal, a foam metal, or the like. Among them, a metal thin film is preferable, a copper foil is more preferable, and a rolled copper foil by a rolling method and an electrolytic copper foil by an electrolytic method are more preferable.

(Iii) Ratio of thickness between current collector and negative electrode active material layer The ratio of thickness between current collector and negative electrode active material layer is not particularly limited, but "(one side immediately before the injection process of non-aqueous electrolyte solution) The value of "negative electrode active material layer thickness) / (thickness of current collector)" is preferably 150 or less, more preferably 20 or less, particularly preferably 10 or less, and preferably 0.1 or more.
0.4 or more is more preferable, and 1 or more is particularly preferable.
If the ratio of the thickness of the current collector to the negative electrode active material layer exceeds the above range, the current collector may generate heat due to Joule heat during high current density charging / discharging of the secondary battery. Also, if it falls below the above range,
The volume ratio of the current collector to the negative electrode active material may increase, and the capacity of the secondary battery may decrease.

(Iv) Electrode density The electrode structure when the negative electrode active material is converted into an electrode is not particularly limited, and the density of the negative electrode active material existing on the current collector is preferably 1 g · cm ^-3 or more. .2g · ^{cm -3} or more preferably, 1.3 g · ^{cm -3} or more, and also preferably 4g · ^{cm -3} or less, more preferably 3 g · ^{cm -3} or less, 2.5 g · cm ^{- 3} or less is more preferable, 1.7
G · cm ^-3 or less is particularly preferable. When the density of the negative electrode active material existing on the current collector is within the above range, the negative electrode active material particles are less likely to be destroyed, the initial irreversible capacity of the secondary battery increases, and
It becomes easy to prevent deterioration of high current density charge / discharge characteristics due to a decrease in permeability of the non-aqueous electrolyte solution near the current collector / negative electrode active material interface. Further, the conductivity between the negative electrode active materials can be ensured, and the capacity per unit volume can be increased without increasing the battery resistance.

(V) Binder, solvent, etc. A slurry for forming a negative electrode active material layer is usually prepared by adding a mixture of a binder (binding agent), a thickener, etc. to a negative electrode active material. To.
The binder for binding the negative electrode active material is not particularly limited as long as it is a non-aqueous electrolytic solution or a material stable to the solvent used in electrode production.

Specific examples thereof include polyethylene, polypropylene, polyethylene terephthalate, and the like.
Resin-based polymers such as polymethylmethacrylate, aromatic polyamide, cellulose, and nitrocellulose;
Rubbery polymers such as SBR (styrene-butadiene rubber), isoprene rubber, butadiene rubber, fluorine rubber, NBR (acrylonitrile-butadiene rubber), ethylene propylene rubber;
Styrene-butadiene-styrene block copolymer or its hydrogenated product;
Thermoplastic elastomers such as EPDM (ethylene / propylene / diene ternary copolymer), styrene / ethylene / butadiene / styrene copolymer, styrene / isoprene / styrene block copolymer or hydrogenated products thereof;
Soft resinous polymers such as syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene / vinyl acetate copolymers, propylene / α-olefin copolymers;
Fluorine-based polymers such as polyvinylidene fluoride, polytetrafluoroethylene, fluorinated polyvinylidene fluoride, and polytetrafluoroethylene / ethylene copolymer;
Examples thereof include polymer compositions having ionic conductivity of alkali metal ions (particularly lithium ions). These may be used alone or in any combination and ratio of two or more.

The type of solvent for forming the slurry is particularly limited as long as it is a solvent capable of dissolving or dispersing the negative electrode active material, the binder, and the thickener and the conductive material used as needed. However, either an aqueous solvent or an organic solvent may be used.
Examples of the aqueous solvent include water, alcohol and the like, and examples of the organic solvent include N-methylpyrrolidone (NMP), dimethylformamide, dimethylacetamide, methylethylketone, cyclohexanone, methyl acetate, methyl acrylate, diethyltriamine. , N, N-dimethylaminopropylamine, tetrahydrofuran (THF), toluene, acetone, diethyl ether, dimethylacetamide, hexamethylphosphalamide, dimethylsulfoxide, benzene, xylene, quinoline, pyridine, methylnaphthalene, hexane, etc. Can be mentioned.

In particular, when an aqueous solvent is used, it is preferable to include a dispersant or the like in addition to the thickener and slurry using a latex such as SBR.
As these solvents, one type may be used alone, or two or more types may be used in any combination and ratio.
The ratio of the binder to 100 parts by mass of the negative electrode active material is preferably 0.1 part by mass or more, and is 0.
.. 5 parts by mass or more is more preferable, 0.6 parts by mass or more is further preferable, 20 parts by mass or less is preferable, 15 parts by mass or less is more preferable, 10 parts by mass or less is further preferable, and 8 parts by mass or less is particularly preferable. .. When the ratio of the binder to the negative electrode active material is within the above range, the ratio of the binder that does not contribute to the battery capacity does not increase, so that the battery capacity is less likely to decrease. Further, the strength of the negative electrode is less likely to decrease.

In particular, when the slurry as the negative electrode forming material contains a rubbery polymer typified by SBR as a main component, the ratio of the binder to 100 parts by mass of the negative electrode active material is preferably 0.1 part by mass or more, and is 0. .5 parts by mass or more is more preferable, and 0.6 parts by mass or more is further preferable.
Further, 5 parts by mass or less is preferable, 3 parts by mass or less is more preferable, and 2 parts by mass or less is further preferable.

When the slurry contains a fluorine-based polymer typified by polyvinylidene fluoride as a main component, the ratio of the binder to 100 parts by mass of the negative electrode active material is preferably 1 part by mass or more, more preferably 2 parts by mass or more. Preferably, 3 parts by mass or more is further preferable, 15 parts by mass or less is preferable, 10 parts by mass or less is more preferable, and 8 parts by mass or less is further preferable.
Thickeners are commonly used to adjust the viscosity of the slurry. The thickener is not particularly limited, and specific examples thereof include carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein, and salts thereof. These can be used alone or
Two or more types may be used in any combination and ratio.

When a thickener is used, the ratio of the thickener to 100 parts by mass of the negative electrode active material is usually 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and more preferably 0.6 parts by mass or more. The ratio is usually 5 parts by mass or less, preferably 3 parts by mass or less, and more preferably 2 parts by mass or less. When the ratio of the thickener to the negative electrode active material is within the above range, the coating property of the slurry is good. Further, the ratio of the negative electrode active material to the negative electrode active material layer becomes appropriate, and the problem of a decrease in battery capacity and the problem of an increase in resistance between the negative electrode active materials are less likely to occur.

(Vi) Area of the negative electrode plate The area of the negative electrode plate is not particularly limited, but it is preferable to design the area so that the positive electrode plate does not protrude from the negative electrode plate by making it slightly larger than the facing positive electrode plate. In addition, from the viewpoint of suppressing deterioration due to cycle life and high-temperature storage when the secondary battery is repeatedly charged and discharged,
It is preferable to bring the area as close to the positive electrode as possible because the proportion of electrodes that work more uniformly and effectively is increased and the characteristics are improved. In particular, when the secondary battery is used with a large current, it is important to design the area of the negative electrode plate.

<4-1-4. Positive electrode>
The positive electrode used in the non-aqueous electrolyte secondary battery of the present invention will be described below.
<4-1-4-1. Positive electrode active material>
The positive electrode active material used for the positive electrode will be described below.

(1) Composition The positive electrode active material is not particularly limited as long as it can electrochemically occlude and release metal ions, but for example, a material capable of electrochemically occluding and releasing lithium ions is preferable.
Substances containing lithium and at least one transition metal are preferred. Specific examples include a lithium transition metal composite oxide, a lithium-containing transition metal phosphoric acid compound, a lithium-containing transition metal silicic acid compound, and a lithium-containing transition metal borate compound.

The transition metals of the lithium transition metal composite oxide include V, Ti, Cr, Mn, Fe, and C.
O, Ni, Cu and the like are preferable, and specific examples of the composite oxide include a lithium-cobalt composite oxide such as LiCoO ₂ , a lithium-nickel composite oxide such as LiNiO ₂ , and LiMn.
Lithium-manganese composite oxides such as O ₂ , LiMn ₂ O ₄ , Li ₂ MnO ₄ , and some of the transition metal atoms that are the main constituents of these lithium transition metal composite oxides are Al, Ti, V, Cr, and M.
n, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn
, W and the like substituted with other metals.

Specific examples of the substituted ones include, for example, LiNi _0.5 Mn _0.5 O ₂ , LiNi.
_0.85 Co _0.10 Al _0.05 O ₂ , LiNi _0.33 Co _0.33 Mn _0.33 O
₂ , LiMn ₂ O ₄ , LiMn _1.8 Al _0.2 O ₄ , Li _1.1 Mn _1.9 Al _0.1
Examples thereof include O ₄ , LiMn _1.5 Ni _0.5 O ₄ .
Of these, composite oxides containing lithium, nickel and cobalt are more preferable. This is because the composite oxide containing cobalt and nickel can have a large capacity when used at the same potential.

On the other hand, cobalt is an expensive metal with a small amount of resources, and since the amount of active material used is large in large batteries that require high capacity such as for automobiles, it is a cheaper transition metal in terms of cost. It is also desirable to use manganese as the main component. That is, a lithium-nickel-cobalt-manganese composite oxide is more preferable. Among them, a lithium-nickel-cobalt-manganese composite oxide in which the amount of cobalt used is reduced and the amount of nickel used is increased is particularly preferable from the viewpoint of highly satisfying the balance between cost and capacity. For example, LiNi _0.
5 Co _0.2 Mn _0.3 O ₂ and LiNi _0.6 Co _0.2 Mn _0.2 O ₂ and LiNi _0.
8 Co _0.1 Mn _0.1 O _{2 and the} like are particularly preferable specific examples.

In addition, a lithium manganese composite oxide having a spinel-type structure is also preferable in consideration of stability as a compound and procurement cost due to ease of production. That is, among the above specific examples, LiMn ₂ O ₄ , LiMn _1.8 Al _0.2 O ₄ , Li _1.1 Mn _1.9 Al _0.1 O ₄
, LiMn _1.5 Ni _0.5 O _{4 and the} like can also be mentioned as preferable specific examples.
Examples of the transition metal of the lithium-containing transition metal phosphoric acid compound include V, Ti, Cr, Mn, and F.
e, Co, Ni, Cu and the like are preferable, and specific examples of the phosphoric acid compound include, for example, LiF.
Iron phosphates such as ePO ₄ , Li ₃ Fe ₂ (PO ₄ ) ₃ , LiFeP ₂ O ₇ , LiCoPO ₄
Cobalt phosphates such as LiMnPO ₄ , manganese phosphates such as LiMnPO ₄ , and some of the transition metal atoms that are the main constituents of these lithium transition metal phosphoric acid compounds are Al, Ti, V, Cr, Mn, Fe, Co,
Examples thereof include those substituted with other metals such as Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn and W.

Examples of the transition metal of the lithium-containing transition metal silicic acid compound include V, Ti, Cr, Mn, and the like.
Fe, Co, Ni, Cu and the like are preferable, and specific examples of the silicic acid compound include, for example, L.
Iron silicates such as i ₂ FeSiO _4, cobalt silicates such as Li ₂ CoSiO ₄ , and some of the transition metal atoms that are the main constituents of these lithium transition metal silicic acid compounds are Al, Ti, V, Cr.
, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo,
Examples thereof include those substituted with other metals such as Sn and W.

Examples of the transition metal of the lithium-containing transition metal boric acid compound include V, Ti, Cr, Mn, and the like.
Fe, Co, Ni, Cu and the like are preferable, and specific examples of the boric acid compound include, for example, L.
Iron borates such as iFeBO _3, cobalt borates such as LiCoBO ₃ , and some of the transition metal atoms that are the main constituents of these lithium transition metal boric acid compounds are Al, Ti, V, Cr, Mn,
Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, W
Examples thereof include those substituted with other metals such as.

(2) Method for Producing Positive Electrode Active Material The method for producing the positive electrode active material is not particularly limited as long as it does not exceed the gist of the present invention.
Several methods are mentioned, and a general method is used as a method for producing an inorganic compound.
In particular, various methods can be considered for producing spherical or elliptical spherical active materials. For example, transition metal raw materials such as transition metal nitrates and sulfates and, if necessary, raw materials of other elements are used. It is dissolved or pulverized and dispersed in a solvent such as water, the pH is adjusted while stirring to prepare and recover a spherical precursor, which is dried as necessary, and then LiOH, Li ₂ CO ₃ , Li.
Examples thereof include a method of adding a Li source such as NO ₃ and firing at a high temperature to obtain an active material.

Further, as an example of another method, a transition metal raw material such as a transition metal nitrate, a sulfate, a hydroxide, or an oxide and, if necessary, a raw material of another element are dissolved or pulverized and dispersed in a solvent such as water. do it,
It is dried and molded with a spray dryer or the like to form a spherical or elliptical spherical precursor, which is then L.
Examples thereof include a method of adding a Li source such as iOH, Li ₂ CO ₃ and LiNO ₃ and firing at a high temperature to obtain an active material.

As an example of yet another method, a transition metal raw material such as a transition metal nitrate, a sulfate, a hydroxide, an oxide, a Li source such as LiOH, Li ₂ CO ₃ , LiNO ₃ , and other elements as required. Is a method of dissolving or pulverizing and dispersing the raw material of the above in a solvent such as water, drying and molding it with a spray dryer or the like to obtain a spherical or elliptical spherical precursor, and firing this at a high temperature to obtain an active material. Can be mentioned.

<4-1-4-2. Positive electrode structure and manufacturing method>
The configuration of the positive electrode used in the present invention and the method for producing the same will be described below.

(Method of manufacturing positive electrode)
The positive electrode is produced by forming a positive electrode active material layer containing positive electrode active material particles and a binder on a current collector. The positive electrode using the positive electrode active material can be produced by any known method. For example, a positive electrode active material and a binder, and if necessary, a conductive material and a thickener are mixed in a dry manner to form a sheet, which is then pressure-bonded to a positive electrode current collector, or these materials are dissolved in a liquid medium. Alternatively, a positive electrode can be obtained by forming a positive electrode active material layer on the current collector by dispersing the slurry as a slurry, applying the slurry to the positive electrode current collector, and drying the mixture.

The content of the positive electrode active material in the positive electrode active material layer is preferably 60% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, and preferably 99.9% by mass or less. Yes, 99% by mass or less is more preferable. When the content of the positive electrode active material is within the above range, a sufficient electric capacity can be secured. Further, the strength of the positive electrode is also sufficient. As the positive electrode active material powder in the present invention, one type may be used alone, or two or more types having different compositions or different powder physical properties may be used in combination in any combination and ratio. When two or more kinds of active materials are used in combination, it is preferable to use the composite oxide containing lithium and manganese as a component of the powder. As described above, cobalt or nickel is an expensive metal with a small amount of resources, and is not preferable in terms of cost because the amount of active material used is large in a large battery that requires a high capacity such as for automobile applications. Therefore, it is desirable to use manganese as a main component as a cheaper transition metal.

(Conductive material)
As the conductive material, a known conductive material can be arbitrarily used. Specific examples include metal materials such as copper and nickel; graphite (graphite) such as natural graphite and artificial graphite; carbon black such as acetylene black; and carbonaceous materials such as amorphous carbon such as needle coke. It should be noted that one of these may be used alone, or two or more thereof may be used in any combination and ratio.
The content of the conductive material in the positive electrode active material layer is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, further preferably 1% by mass or more, and preferably 50% by mass or less. It is more preferably 30% by mass or less, and further preferably 15% by mass or less. When the content is within the above range, sufficient conductivity can be ensured. Furthermore, it is easy to prevent a decrease in battery capacity.

(Binder)
The binder used for producing the positive electrode active material layer is not particularly limited as long as it is a material stable to a non-aqueous electrolytic solution or a solvent used for producing an electrode.
When the positive electrode is produced by the coating method, the binder is not particularly limited as long as it is a material that is dissolved or dispersed in the liquid medium used in the electrode production, and specific examples thereof include polyethylene.
Resin-based polymers such as polypropylene, polyethylene terephthalate, polymethylmethacrylate, aromatic polyamide, cellulose, and nitrocellulose;
SBR (Styrene-butadiene rubber), NBR (Acrylonitrile-butadiene rubber)
, Fluororubber, isoprene rubber, butadiene rubber, ethylene / propylene rubber and other rubbery polymers;
Styrene / butadiene / styrene block copolymer or hydrogen additive thereof, EPDM (ethylene / propylene / diene ternary copolymer), styrene / ethylene / butadiene / ethylene copolymer, styrene / isoprene / styrene block copolymer or A thermoplastic elastomer such as the hydrogenated product;
Soft resinous polymers such as syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene / vinyl acetate copolymers, propylene / α-olefin copolymers;
Fluorine-based polymers such as polyvinylidene fluoride (PVdF), polytetrafluoroethylene, fluorinated polyvinylidene fluoride, and polytetrafluoroethylene / ethylene copolymer;
Examples thereof include polymer compositions having ionic conductivity of alkali metal ions (particularly lithium ions). In addition, as these substances, 1 type may be used alone, and 2 or more types may be used together in arbitrary combinations and ratios.

The content of the binder in the positive electrode active material layer is preferably 0.1% by mass or more, and 1% by mass.
The above is more preferable, 3% by mass or more is further preferable, 80% by mass or less is preferable, 60% by mass or less is more preferable, 40% by mass or less is further preferable, and 10% by mass or less is particularly preferable. When the ratio of the binder is within the above range, the positive electrode active material can be sufficiently retained.
Since the mechanical strength of the positive electrode can be ensured, the battery performance such as cycle characteristics is improved. further,
It also leads to avoiding a decrease in battery capacity and conductivity.

(Liquid medium)
The liquid medium used to prepare the slurry for forming the positive electrode active material layer is a solvent capable of dissolving or dispersing the positive electrode active material, the conductive material, the binder, and the thickener used as needed. If there is, the type is not particularly limited, and either an aqueous solvent or an organic solvent may be used.

Examples of the aqueous medium include water, a mixed medium of alcohol and water, and the like.
As an example of the organic medium,
Aliphatic hydrocarbons such as hexane;
Aromatic hydrocarbons such as benzene, toluene, xylene, methylnaphthalene;
Heterocyclic compounds such as quinoline and pyridine;
Ketones such as acetone, methyl ethyl ketone, cyclohexanone;
Esters such as methyl acetate and methyl acrylate;
Amines such as diethylenetriamine, N, N-dimethylaminopropylamine;
Ethers such as diethyl ether and tetrahydrofuran (THF);
Amides such as N-methylpyrrolidone (NMP), dimethylformamide, dimethylacetamide;
Examples thereof include aprotic polar solvents such as hexamethylphosphalamide and dimethylsulfoxide. In addition, these may be used individually by 1 type, and may use 2 or more types together in arbitrary combinations and ratios.

(Thickener)
When an aqueous medium is used as the liquid medium for forming the slurry, it is preferable to use a thickener and a latex such as styrene-butadiene rubber (SBR) to form a slurry. Thickeners are commonly used to adjust the viscosity of the slurry.
The thickener is not limited as long as the effect of the present invention is not significantly limited, but specifically, carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein and salts thereof. And so on. These may be used alone or in any combination and ratio of two or more.

When a thickener is used, the ratio of the thickener to the total mass of the positive electrode active material and the thickener is preferably 0.1% by mass or more, more preferably 0.5% by mass or more. 0.6% by mass
The above is more preferable, and it is preferably 5% by mass or less, more preferably 3% by mass or less, and further preferably 2% by mass or less. Within the above range, the coatability of the slurry becomes good, and the ratio of the active material to the positive electrode active material layer becomes sufficient, so that there is a problem that the capacity of the secondary battery decreases and the space between the positive electrode active materials is reduced. It is easier to avoid the problem of increased resistance.

(Consolidation)
The positive electrode active material layer obtained by applying the slurry to the current collector and drying is preferably consolidated by a hand press, a roller press, or the like in order to increase the packing density of the positive electrode active material. The density of the positive electrode active material layer is preferably 1 g · cm ^-3 or more, more preferably 1.5 g · cm ^-3 or more, particularly preferably 2 g · cm ^-3 or more, and preferably 4 g · cm ^-3 or less. 3.9 g · ^{cm -3} more preferably less, 3.8 g · ^{cm -3} or less are particularly preferred.
When the density of the positive electrode active material layer is within the above range, the permeability of the non-aqueous electrolyte solution to the vicinity of the current collector / active material interface does not decrease, and charging / discharging is performed particularly at a high current density of the secondary battery. The characteristics are good. Further, the conductivity between the active materials is less likely to decrease, and the battery resistance is less likely to increase.

(Current collector)
The material of the positive electrode current collector is not particularly limited, and any known material can be used.
Specific examples include metal materials such as aluminum, stainless steel, nickel plating, titanium and tantalum; and carbonaceous materials such as carbon cloth and carbon paper. Of these, metal materials, especially aluminum, are preferable.

Examples of the shape of the current collector include metal foil, metal cylinder, metal coil, metal plate, metal thin film, expanded metal, punch metal, foamed metal, etc. in the case of metal material, and carbon plate in the case of carbonaceous material. Examples include a carbon thin film and a carbon column. Of these, a metal thin film is preferable.
The thin film may be formed in a mesh shape as appropriate.
The thickness of the current collector is arbitrary, but is preferably 1 μm or more, more preferably 3 μm or more, further preferably 5 μm or more, and preferably 1 mm or less, more preferably 100 μm or less, further preferably 50 μm or less. preferable. When the thickness of the current collector is within the above range, sufficient strength required for the current collector can be secured. Further, the handleability is also good.

The ratio of the thickness of the current collector to the positive electrode active material layer is not particularly limited, but (thickness of the active material layer on one side immediately before injection of the non-aqueous electrolyte solution) / (thickness of the current collector) is preferable. It is 150 or less, more preferably 20 or less, particularly preferably 10 or less, and preferably 0.1 or more, more preferably 0.4 or more, and particularly preferably 1 or more. When the ratio of the thickness of the current collector to the positive electrode active material layer is within the above range, the current collector is less likely to generate heat due to Joule heat during high current density charging / discharging of the secondary battery. Further, the volume ratio of the current collector to the positive electrode active material is unlikely to increase, and a decrease in battery capacity can be prevented.

(Electrode area)
From the viewpoint of improving the stability at high output and high temperature, the area of the positive electrode active material layer is preferably large with respect to the outer surface area of the battery outer case. Specifically, the total area of the electrode areas of the positive electrode with respect to the surface area of the exterior of the non-aqueous electrolyte secondary battery is preferably 20 times or more, and more preferably 40 times or more in terms of area ratio. The outer surface area of the outer case means the total area calculated from the vertical, horizontal, and thickness dimensions of the case part filled with the power generation element excluding the protruding part of the terminal in the case of the bottomed square shape. .. In the case of a bottomed cylindrical shape, the geometric surface area approximates the case portion filled with the power generation element excluding the protruding portion of the terminal as a cylinder. The total electrode area of the positive electrode is the geometric surface area of the positive electrode mixture layer facing the mixture layer containing the negative electrode active material, and in a structure in which the positive electrode mixture layer is formed on both sides via a current collector foil. , Refers to the sum of the areas calculated separately for each surface.

(Discharge capacity)
When the non-aqueous electrolyte solution of the present invention is used, the electric capacity of the battery element housed in one battery exterior of the non-aqueous electrolyte secondary battery (electrical capacity when the battery is discharged from a fully charged state to a discharged state). ) Is 1 amper hour (Ah) or more, which is preferable because the effect of improving the low temperature discharge characteristics is large. Therefore, the positive electrode plate has a fully charged discharge capacity, preferably 3 Ah (ampere hour), more preferably 4 Ah or more, and preferably 20 Ah or less.
More preferably, it is designed to be 10 Ah or less.

If it is within the above range, the voltage drop due to the electrode reaction resistance does not become too large when a large current is taken out, and deterioration of power efficiency can be prevented. Furthermore, the temperature distribution due to internal heat generation of the battery during pulse charging / discharging does not become too large, the durability of repeated charging / discharging is inferior, and the heat dissipation efficiency is also poor against sudden heat generation at the time of abnormalities such as overcharging and internal short circuit. It is possible to avoid the phenomenon of becoming.

(Thickness of positive electrode plate)
The thickness of the positive electrode plate is not particularly limited, but from the viewpoint of high capacity, high output, and high rate characteristics,
The thickness of the positive electrode active material layer obtained by subtracting the thickness of the current collector is preferably 10 μm or more, more preferably 20 μm or more, and preferably 200 μm or less, 150 μm with respect to one side of the current collector.
More preferably m or less.

<4-1-5. Separator>
In the non-aqueous electrolyte secondary battery of the present invention, a separator is usually interposed between the positive electrode and the negative electrode in order to prevent a short circuit. In this case, the non-aqueous electrolyte solution of the present invention is usually used by impregnating this separator.
The material and shape of the separator are not particularly limited, and any known separator can be used as long as the effects of the present invention are not significantly impaired. Among them, resins, glass fibers, inorganic substances and the like formed of a material stable to the non-aqueous electrolytic solution of the present invention are used, and a porous sheet or a non-woven fabric-like material having excellent liquid retention property is used. Is preferable.

As the material of the resin and the glass fiber separator, for example, polyolefins such as polyethylene and polypropylene, aramid resin, polytetrafluoroethylene, polyether sulfone, glass filter and the like can be used. Of these, glass filters and polyolefins are preferable, and polyolefins are more preferable. One of these materials may be used alone, or two or more of these materials may be used in any combination and ratio.

The thickness of the separator is arbitrary, but is preferably 1 μm or more, more preferably 5 μm or more, further preferably 10 μm or more, and preferably 50 μm or less, 40.
It is more preferably μm or less, and further preferably 30 μm or less. When the thickness of the separator is within the above range, the insulating property and the mechanical strength are good. Further, it is possible to prevent a decrease in battery performance such as rate characteristics, and it is also possible to prevent a decrease in energy density of the non-aqueous electrolyte secondary battery as a whole.

Further, when a porous material such as a porous sheet or a non-woven fabric is used as the separator, the porosity of the separator is arbitrary, but is preferably 20% or more, more preferably 35% or more, and further 45% or more. It is preferable, preferably 90% or less, more preferably 85% or less, still more preferably 75% or less. When the porosity is within the above range, the film resistance does not become too large, and deterioration of the rate characteristics of the secondary battery can be suppressed. Further, the mechanical strength of the separator becomes appropriate, and the deterioration of the insulating property can be suppressed.

The average pore size of the separator is also arbitrary, but is preferably 0.5 μm or less, and 0.
It is more preferably 2 μm or less, and preferably 0.05 μm or more. When the average hole diameter is within the above range, a short circuit is unlikely to occur. Further, the film resistance does not become too large, and it is possible to prevent a decrease in the rate characteristics of the secondary battery.
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, and have a particle shape or a fiber shape. Things are used.

As the form of the separator, a thin film such as a non-woven fabric, a woven cloth, or a microporous film is used. As the thin film-shaped separator, 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 independent thin film shape, a separator formed by forming a composite porous layer containing the inorganic particles on the surface layer of the positive electrode and / or the negative electrode using a resin binder can be used. For example, alumina particles having a 90% particle size of less than 1 μm are used on both sides of the positive electrode, and a fluororesin is used as a binder to form a porous layer.

<4-1-6. Battery design>
(Electrode group)
The electrode group has a laminated structure in which the above-mentioned positive electrode plate and the above-mentioned negative electrode plate are interposed via the above-mentioned separator.
And any of the above-mentioned positive electrode plate and negative electrode plate having a structure in which the above-mentioned positive electrode plate and the negative electrode plate are spirally wound via the above-mentioned separator. The ratio of the volume of the electrode group to the internal volume of the battery (hereinafter referred to as the electrode group occupancy rate) is preferably 40% or more, more preferably 50% or more, and preferably 9
It is 5% or less, more preferably 90% or less. When the electrode group occupancy rate is within the above range, the battery capacity is unlikely to be reduced. In addition, since an appropriate gap space can be secured, the internal pressure rises due to the expansion of the member due to the high temperature of the battery and the increase of the vapor pressure of the liquid component of the non-aqueous electrolyte solution, so that the battery can be used as a secondary battery. It is possible to reduce various characteristics such as charge / discharge repetition performance and high temperature storage characteristics, and to avoid the case where the gas discharge valve that releases the internal pressure to the outside operates.

(Current collector structure)
The current collecting structure is not particularly limited, but in order to more effectively improve the discharge characteristics of the non-aqueous electrolyte solution of the present invention, it is necessary to use a structure that reduces the resistance of the wiring portion and the joint portion. preferable. When the internal resistance is reduced in this way, the effect of using the non-aqueous electrolyte solution of the present invention is particularly well exhibited.

When the electrode group has the above-mentioned laminated structure, a structure formed by bundling the metal core portions of each electrode layer and welding them to the terminals is preferably used. When the area of one electrode becomes large, the internal resistance becomes large. Therefore, it is also preferably used to reduce the resistance by providing a plurality of terminals in the electrode. In the case where the electrode group has the above-mentioned wound structure, the internal resistance can be lowered by providing a plurality of lead structures on the positive electrode and the negative electrode and bundling them in the terminals.

(Protective element)
As a protective element, PTC (Posit) whose resistance increases when abnormal heat generation or excessive current flows
Examples include an ive Temperature Cofficient) thermistor, a thermal fuse, and a valve (current cutoff valve) that shuts off the current flowing through the circuit due to a sudden rise in the internal pressure or temperature of the battery when abnormal heat is generated. It is preferable to select the protective element under conditions that do not operate under normal use with a high current, and it is more preferable to design the battery so that abnormal heat generation or thermal runaway does not occur even without the protective element.

(Exterior body)
The non-aqueous electrolyte secondary battery of the present invention is usually configured by accommodating the above-mentioned non-aqueous electrolyte, negative electrode, positive electrode, separator and the like in an exterior body (exterior case). There is no limitation on this exterior body, and a known one can be arbitrarily adopted as long as the effect of the present invention is not significantly impaired.
The material of the outer case is not particularly limited as long as it is a substance stable to the non-aqueous electrolyte solution used. Specifically, a nickel-plated steel plate, stainless steel, aluminum or aluminum alloy, magnesium alloy, metals such as nickel and titanium, or a laminated film (laminated film) of resin and aluminum foil is used. From the viewpoint of weight reduction, aluminum or aluminum alloy metal or laminated film is preferably used.

In the outer case using the above metals, the metals are welded together by laser welding, resistance welding, or ultrasonic welding to form a sealed and sealed structure, or the above metals are used to caulk the structure via a resin gasket. There are things to do. Examples of the outer case using the above-mentioned laminated film include a case in which resin layers are heat-sealed to form a sealed and sealed structure. In order to improve the sealing property, a resin different from the resin used for the laminate film may be interposed between the resin layers. In particular, when the resin layer is heat-sealed via the current collector terminal to form a closed structure, the metal and the resin are bonded to each other. Therefore, a resin having a polar group or a modification in which a polar group is introduced as an intervening resin is introduced. Resin is preferably used.
Further, the shape of the outer case is also arbitrary, and may be any of, for example, a cylindrical type, a square shape, a laminated type, a coin type, and a large size.

<4-2. Non-aqueous electrolyte primary battery ＞
The non-aqueous electrolyte primary battery according to the embodiment of the present invention uses, for example, a material capable of occluding metal ions in the positive electrode and a material capable of releasing metal ions in the negative electrode. As the positive electrode material, transition metal oxides such as graphite fluoride and manganese dioxide are preferable. As the negative electrode material, a simple substance such as zinc or lithium is preferable. As the non-aqueous electrolyte solution, the above-mentioned non-aqueous electrolyte solution of the present invention is used.

<4-3. Metal ion capacitor ＞
As the metal ion capacitor according to the embodiment of the present invention, for example, a material capable of forming an electric double layer is used for the positive electrode, and a material capable of storing and releasing metal ions is used for the negative electrode. Activated carbon is preferable as the positive electrode material. Further, as the negative electrode material, a carbonaceous material is preferable. As the non-aqueous electrolyte solution, the above-mentioned non-aqueous electrolyte solution of the present invention is used.

<4-4. Electric Double Layer Capacitor>
The electric double layer capacitor according to the embodiment of the present invention uses, for example, a material capable of forming an electric double layer for the electrodes. Activated carbon is preferable as the electrode material. As the non-aqueous electrolyte solution, the above-mentioned non-aqueous electrolyte solution of the present invention is used.

Hereinafter, the present invention will be described in more detail with reference to Examples and Reference Examples, but the present invention is not limited to these Examples as long as the gist thereof is not exceeded.

(Example 1)
[Preparation of negative electrode]
98 parts by mass of carbonaceous material, 100 parts by mass of aqueous dispersion of sodium carboxymethyl cellulose (1% by mass of sodium carboxymethyl cellulose concentration) and aqueous dispersion of styrene-butadiene rubber (1% by mass) as a thickener and binder, respectively.
1 part by mass of styrene-butadiene rubber (concentration: 50% by mass) was added and mixed with a disparzer to form a slurry. The obtained slurry was applied to a copper foil having a thickness of 10 μm, dried, and rolled by a press. The size of the active material layer was 30 mm in width, 40 mm in length, and 5 mm in width.
It was cut out into a shape having an uncoated portion having a length of 9 mm, and used as a negative electrode used in the implementation and comparative examples, respectively.

[Preparation of positive electrode]
90% by mass of lithium cobalt oxide as a positive electrode active material, 5% by mass of acetylene black as a conductive material, and 5% by mass of polyvinylidene fluoride (PVdF) as a binder, N-
It was mixed in a methylpyrrolidone solvent to form a slurry. The obtained slurry has a thickness of 15 μm.
It was applied to m aluminum foil, dried, and rolled by a press. The size of the active material layer was cut out into a shape having an uncoated portion having a width of 30 mm, a length of 40 mm, and a width of 5 mm and a length of 9 mm. The positive electrodes used in Examples and Comparative Examples were used, respectively.

[Preparation of non-aqueous electrolyte solution]
Ethyl carbonate (EC) and ethyl methyl carbonate (in a dry argon atmosphere)
The dried LiPF ₆ was dissolved in a mixture with EMC) (volume ratio 30:70) at a ratio of 1 mol / L, and 1% by mass of lithium fluorosulfonate was further contained to prepare a basic electrolytic solution 1. LiHSO ₄ is mixed with this basic electrolytic solution 1 so as to contain 0.01% by mass.
The non-aqueous electrolyte solution of Example 1 was prepared.

[Manufacturing of non-aqueous electrolyte secondary batteries]
The above positive electrode, negative electrode, and polyethylene separator were laminated in this order of the negative electrode, the separator, and the positive electrode to prepare a battery element. After inserting this battery element into a bag made of a laminated film in which both sides of aluminum (thickness 40 μm) are coated with a resin layer while projecting the positive electrode and negative electrode terminals, the non-aqueous electrolyte solution of Example 1 is put in the bag. Was injected into the battery and vacuum-sealed to prepare a sheet-shaped non-aqueous electrolyte secondary battery, which was used as the non-aqueous electrolyte secondary battery of Example 1.

[Initial discharge capacity evaluation]
The non-aqueous electrolyte secondary battery is charged to 4.1 V at 25 ° C. with a constant current equivalent to 0.2 C in a state of being sandwiched between glass plates in order to improve the adhesion between the electrodes, and then 0.2 C. It was discharged to 3.0V with the constant current of. Do this for 2 cycles to stabilize the non-aqueous electrolyte secondary battery.
In the third cycle, after charging to 4.2V with a constant current of 0.2C, charging is performed with a constant voltage of 4.2V until the current value reaches 0.05C, and 3.0V with a constant current of 0.2C. Discharged to. Then, in the 4th cycle, the battery is charged to 4.2 V with a constant current of 0.2 C, charged with a constant voltage of 4.2 V until the current value reaches 0.05 C, and with a constant current of 0.2 C. The initial discharge capacity was determined by discharging to 0 V. Note that 1C represents the current value for discharging the reference capacity of the non-aqueous electrolyte secondary battery in 1 hour, 2C is the current value twice that, and 0.2C is the current value 1/5 of that. Represents.

[Initial swelling evaluation]
The non-aqueous electrolyte secondary battery before the initial discharge capacity evaluation was immersed in an ethanol bath and the volume was measured, and this was taken as the volume before the initial discharge capacity evaluation. Then, the battery for which the initial discharge capacity evaluation test was completed was immersed in an ethanol bath to measure the volume, and this was taken as the volume after the initial discharge evaluation. The value obtained by subtracting the volume before the initial discharge evaluation from the volume after the initial discharge evaluation was defined as the initial swelling.

[Evaluation of swelling after storage]
The non-aqueous electrolyte secondary battery for which the initial discharge capacity evaluation test has been completed is 4.2 at a constant current of 0.2 C.
After charging to V, it was charged at a constant voltage of 4.2 V until the current value reached 0.05 C. This is 85
After storing at ° C for 24 hours and cooling the non-aqueous electrolyte secondary battery, immerse it in an ethanol bath to measure the volume after high temperature storage, and subtract the volume after initial discharge evaluation from the volume after high temperature storage. The value was defined as swelling after storage.

[Evaluation of storage capacity retention rate]
A non-aqueous electrolyte secondary battery whose volume was measured after high temperature storage was discharged to 3.0 V at a constant current of 0.2 C at 25 ° C, charged to 4.2 V with a constant current of 0.2 C, and then at a constant voltage. A test was carried out in which the battery was charged until the current value became 0.05 C and discharged to 3.0 V at a constant current of 0.2 C, and the discharge capacity after high temperature storage at 0.2 C was determined. Furthermore, from the following formula, the storage capacity retention rate (%)
) Was asked.

Storage capacity retention rate (%) = (Discharge capacity after high temperature storage) ÷ (Initial discharge capacity) x 100
(Comparative Example 1)
A sheet-shaped non-aqueous electrolyte secondary battery of Comparative Example 1 was prepared and evaluated in the same manner as in Example 1 except that Li ₂ SO ₄ was used instead of Li HSO ₄ .
The evaluation results of Example 1 are shown in Table 1 as relative values when the value of Comparative Example 1 is set to 100.

As is clear from Table 1, when LiHSO ₄ is contained in the basic electrolyte 1 (Example 1).
Shows better initial discharge capacity, initial swelling, storage capacity retention rate, and swelling after storage than when Li ₂ SO ₄ which is a similar compound is contained (Comparative Example 1), and LiHSO ₄ should be selected. Is clearly important.

(Example 2)
[Manufacturing of non-aqueous electrolyte secondary batteries]
Ethyl carbonate (EC) and ethyl methyl carbonate (in a dry argon atmosphere)
The dried LiPF ₆ was dissolved in a mixture with EMC) (volume ratio 30:70) at a ratio of 1.5 mol / L, and 0.5% by mass of lithium fluorosulfonate was further contained in the basic electrolyte 2 Was prepared. LiHSO ₄ is mixed with this basic electrolytic solution 2 so as to contain 0.01% by mass to prepare a non-aqueous electrolytic solution of Example 2, and a sheet-shaped non-aqueous electrolytic solution 2 is prepared in the same manner as in Example 1. The next battery was prepared and evaluated.

(Comparative Example 2)
A sheet-shaped non-aqueous electrolyte secondary battery of Comparative Example 2 was prepared in the same manner as in Example 2 except that Li ₂ SO ₄ was used instead of Li HSO ₄ , and the same evaluation was performed.
The evaluation results of Example 2 are shown in Table 2 as relative values when the value of Comparative Example 2 is 100.

As is clear from Table 2, when LiHSO ₄ is contained in the basic electrolyte 2 (Example 2).
Shows better initial swelling, storage capacity retention rate, and swelling after storage than when Li ₂ SO ₄ which is a similar compound is contained (Comparative Example 2), and it is important to select LiHSO _4. It is clear that.

(Example 3)
[Manufacturing of non-aqueous electrolyte secondary batteries]
Ethyl carbonate (EC) and ethyl methyl carbonate (in a dry argon atmosphere)
Dry LiPF ₆ was dissolved in a mixture with EMC) (volume ratio 30:70) at a ratio of 1 mol / L, and 0.025% by mass of lithium fluorosulfonate was further contained to prepare a basic electrolyte 3. did. LiHSO ₄ is mixed with this basic electrolytic solution 3 so as to contain 0.001% by mass to prepare a non-aqueous electrolytic solution of Example 3, and a sheet-shaped non-aqueous electrolytic solution 2 is prepared in the same manner as in Example 1. The next battery was prepared and evaluated.

(Comparative Example 3)
A sheet-shaped non-aqueous electrolyte secondary battery of Comparative Example 3 was prepared in the same manner as in Example 3 except that Li ₂ SO ₄ was used instead of Li HSO ₄ , and the same evaluation was performed.
The evaluation results of Example 3 are shown in Table 3 as relative values when the value of Comparative Example 3 is 100.

As is clear from Table 3, when LiHSO ₄ is contained in the basic electrolyte 3 (Example 3).
Shows better initial discharge capacity, initial swelling, storage capacity retention rate, and swelling after storage than when Li ₂ SO ₄ which is a similar compound is contained (Comparative Example 3), and LiHSO ₄ should be selected. Is clearly important.

According to the non-aqueous electrolyte solution of the present invention, the initial characteristics and durability of the non-aqueous electrolyte secondary battery can be improved, which is useful. Therefore, the non-aqueous electrolyte solution of the present invention and the energy device such as the non-aqueous electrolyte solution secondary battery using the same can be used for various known applications. Specific examples include, for example, laptop computers, pen input computers, mobile computers, electronic book players, mobile phones, mobile fax machines, mobile copies, mobile printers, headphone stereos, video movies, LCD TVs, handy cleaners, portable CDs, and mini discs. , Transceivers, electronic organizers, calculators, memory cards, portable tape recorders, radios, backup power supplies, motors, automobiles, bikes, motorized bicycles, bicycles, lighting equipment, toys, game equipment, watches, power tools, strobes, cameras, homes Examples include a backup power supply for business use, a backup power supply for business establishments, a power supply for load leveling, a natural energy storage power supply, and a lithium ion capacitor.

Claims (5)

The L containing an electrolyte, a non-aqueous solvent and LiHSO ₄ and with respect to the entire non-aqueous electrolyte solution.
A non-aqueous electrolyte solution having an iHSO ₄ content of 0.1% by mass or less. Cyclic carbonates having a fluorine atom, a carbon - cyclic carbonate having a carbon-carbon unsaturated bond, difluorophosphate, salts having a FSO ₂ structure, a compound having an isocyanato group, a compound having a cyano group, a cyclic sulfonic acid esters and dicarboxylic acid complexes The non-aqueous electrolyte solution according to claim 1, which contains at least one specific compound selected from the group consisting of salts. The non-aqueous electrolyte solution according to claim 1 or 2, which contains LiPF ₆ as the electrolyte. An energy device including a plurality of electrodes capable of storing and releasing metal ions, and the non-aqueous electrolyte solution according to any one of claims 1 to 3. The plurality of electrodes capable of occluding and releasing the metal ions are a positive electrode and a negative electrode, and the negative electrode is
The energy device according to claim 4, which comprises a carbonaceous material or a material containing silicon.