JP2021122006A - Non-aqueous electrolyte and non-aqueous electrolyte battery - Google Patents

Abstract

To provide a non-aqueous electrolyte that is excellent in suppressing an increase in internal resistance during high-temperature storage of a battery.SOLUTION: A non-aqueous electrolyte includes an alkali metal salt and non-aqueous solvents, a compound having at least one Si-O structure selected from a compound represented by a general formula (A) and a compound represented by a general formula (B), and a compound represented by the general formula (α).SELECTED DRAWING: None

Description

The present invention relates to a non-aqueous electrolyte solution and a non-aqueous electrolyte battery, and more particularly to a non-aqueous electrolyte solution containing a specific compound and a non-aqueous electrolyte battery using the non-aqueous electrolyte solution.

Non-aqueous electrolyte batteries such as lithium secondary batteries are practically used in a wide range of applications such as power supplies for mobile phones such as smartphones and so-called consumer small devices such as laptop computers, and in-vehicle power supplies for driving such as electric vehicles. It has been transformed.

As a means for improving the battery characteristics of a non-aqueous electrolyte battery, many studies have been made in the fields of positive electrode and negative electrode active materials and non-aqueous electrolyte solution additives.

For example, Patent Document 1 discloses a study for improving cycle characteristics and high-temperature storage characteristics by adding a nitrile compound and a phenylsiloxane compound to a non-aqueous electrolytic solution.
Non-Patent Document 1 describes a non-aqueous electrolyte solution (2-allylphenoxy) trimeth.
A study to improve cycle stability (cycle capacity retention rate) by removing fluorine in the electrolytic solution and protecting the layered lithium / manganese-rich oxide (LMR) positive electrode by adding ylsialane is disclosed. ing.

Korean Publication No. 10-2017-00148889

Journal of Materials Chemistry A: Materials for Energy and Sustainability, Volume6, Issue36, Pages 17642-17652

In recent years, the increase in capacity of lithium batteries has been accelerated for in-vehicle power supplies of electric vehicles and mobile phone power supplies such as smartphones, and there is a demand for batteries having excellent quick charging characteristics for charging batteries in a short time. There is. Therefore, a large increase in the internal resistance of the battery due to placing the battery in a high temperature environment hinders quick charging, which is a fatal drawback.

An object of the present invention is to provide a non-aqueous electrolyte solution excellent in suppressing an increase in internal resistance during high-temperature storage of a battery. Another object of the present invention is to provide a non-aqueous electrolyte battery in which an increase in internal resistance during high-temperature storage is suppressed.

The present inventor contains a compound having at least one Si—O structure selected from a compound represented by the general formula (A) and a compound represented by the general formula (B), and has a general formula (α). ), By using a non-aqueous electrolyte solution containing a compound having a structure in which a Si atom and a benzene ring are bonded via an oxygen atom or a carbon atom, and in which the amount of these compounds added is appropriately adjusted. We have found that an increase in the internal resistance of a battery during high-temperature storage can be suppressed, and have reached the present invention.

（式（Ａ）中、Ｒ^１〜Ｒ^３は、それぞれ独立に、水素原子、ハロゲン原子、置換基を有していてもよい炭素数１〜１２の炭化水素基、又は置換基を有していてもよい炭素数１〜１２のアルコキシ基を示し、Ｘは置換基を有していてもよい炭素数１〜１２の炭化水素基、又は−ＳｉＲ^ｏＲ^ｐＲ^ｑで表されるシリル基を示す。Ｒ^ｏ〜Ｒ^ｑは、それぞれ独立に、水素原子、ハロゲン原子、置換基を有していてもよい炭素数１〜１２の炭化水素基、又は置換基を有していてもよい炭素数１〜１２のアルコキシ基を示す。）

（式（Ｂ）中、Ｒ^４〜Ｒ^５は、それぞれ独立に、水素原子、ハロゲン原子、置換基を有していてもよい炭素数１〜１２の炭化水素基、又は置換基を有していてもよい炭素数１〜１２のアルコキシ基を示し、ｋは３〜６の整数を示す。）

（式（α）中、Ｒ^６〜Ｒ^８は、それぞれ独立に、水素原子、ハロゲン原子、置換基を有していてもよい炭素数１〜１２の炭化水素基、又は置換基を有していてもよい炭素数１〜１２のアルコキシ基を示す。Ｒ^９〜Ｒ^１３は、それぞれ独立に、水素原子、ハロゲン原子、置換基を有していてもよい炭素数１〜１２の炭化水素基、置換基を有していてもよい炭素数１〜１２のアルコキシ基、又は−ＯＳｉＲ^ｒＲ^ｓＲ^ｔで表されるシリルオキシ基を示す。Ｒ^ｒ〜Ｒ^ｔは、それぞれ独立に、置換基を有していてもよい炭素数１〜１２の炭化水素基、又は置換基を有していてもよい炭素数１〜１２のアルコキシ基を示す。Ｙは単結合、酸素原子、又は置換基を有していてもよい炭素数１〜６のアルキレン基を示す。）
＜２＞前記Ｓｉ−Ｏ構造を有する化合物の含有量が非水系電解液の全量に対して１.０×
１０^−３質量％〜１０質量％である、＜１＞に記載の非水系電解液。
＜３＞前記一般式（α）で表される化合物の含有量が非水系電解液の全量に対して０．０１質量ｐｐｍ以上０．５質量％未満である、＜１＞又は＜２＞に記載の非水系電解液。
＜４＞非水系電解液中における前記一般式（α）で表される化合物の含有量に対する前記
Ｓｉ−Ｏ構造を有する化合物の含有量の比が１．０以上１.０×１０^４以下である、＜１
＞〜＜３＞のいずれかに記載の非水系電解液。
＜５＞前記Ｒ^１〜Ｒ^３の少なくとも１つは炭素−炭素不飽和結合を有する炭素数２〜１２の炭化水素基である、＜１＞〜＜４＞のいずれかに記載の非水系電解液。
＜６＞前記Ｒ^６〜Ｒ^８は、それぞれ独立に、置換基を有していてもよい炭素数１〜１２の炭化水素基、又は置換基を有していてもよい炭素数１〜１２のアルコキシ基である、＜１＞〜＜５＞のいずれかに記載の非水系電解液。
＜７＞金属イオンを吸蔵及び放出しうる正極並びに負極と、非水系電解液とを備えた非水系電解液電池であって、該非水系電解液が＜１＞〜＜６＞のいずれかに記載の非水系電解液である、非水系電解液電池。 The present invention provides the following aspects and the like.
<1> A non-aqueous electrolyte solution for a non-aqueous electrolyte battery having a positive electrode and a negative electrode capable of occluding and releasing metal ions, wherein the non-aqueous electrolyte solution is a general formula (A) together with an alkali metal salt and a non-aqueous solvent. The compound having at least one Si—O structure selected from the compound represented by the general formula (B) and the compound represented by the general formula (B) is contained, and the compound represented by the general formula (α) is contained. A non-aqueous electrolyte solution characterized by.

(In the formula (A), R ^{1 to} R ³ each independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a substituent. It represents an alkoxy group having 1 to 12 carbon atoms, and X is a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a silyl group represented by ^{−SiR o} R ^p R ^q. R ^{o to} R ^q each independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a hydrocarbon group which may have a substituent. 1 to 12 alkoxy groups are shown.)

(In the formula (B), R ^{4 to} R ⁵ each independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a substituent. It indicates an alkoxy group having 1 to 12 carbon atoms which may be used, and k indicates an integer of 3 to 6).

(In the formula (α), R ^{6 to} R ⁸ each independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a substituent. The alkoxy groups having 1 to 12 carbon atoms may be shown. R ^{9 to} R ¹³ are hydrocarbon groups having 1 to 12 carbon atoms which may independently have a hydrogen atom, a halogen atom and a substituent. An alkoxy group having 1 to 12 carbon atoms which may have a substituent or a silyloxy group represented by ^{−OSiR r} R ^s R ^{t. R r to} R ^t each independently have a substituent. Indicates a hydrocarbon group having 1 to 12 carbon atoms which may be used, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent. Y has a single bond, an oxygen atom, or a substituent. Indicates an alkylene group having 1 to 6 carbon atoms which may be present.)
<2> The content of the compound having the Si—O structure is 1.0 × with respect to the total amount of the non-aqueous electrolyte solution.
10. The non-aqueous electrolyte solution according to <1>, which is ^{10-3% by mass to 10% by mass.}
<3> In <1> or <2>, the content of the compound represented by the general formula (α) is 0.01 mass ppm or more and less than 0.5 mass% with respect to the total amount of the non-aqueous electrolyte solution. The non-aqueous electrolyte solution described.
<4> the formula (alpha) the ratio of the content of the compound having the Si-O structure to the content of compound represented by at least 1.0 1.0 × 10 ⁴ or less in the nonaqueous electrolytic solution Yes, <1
> To the non-aqueous electrolyte solution according to any one of <3>.
<5> ^{The non-aqueous electrolyte according to any one of <1> to <4>, wherein at least one of R 1 to} R ³ is a hydrocarbon group having a carbon-carbon unsaturated bond and having 2 to 12 carbon atoms. liquid.
<6> The R ^{6 to} R ⁸ each independently have a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or 1 to 12 carbon atoms which may have a substituent. The non-aqueous electrolyte solution according to any one of <1> to <5>, which is an alkoxy group.
<7> A non-aqueous electrolyte battery comprising a positive electrode and a negative electrode capable of occluding and releasing metal ions and a non-aqueous electrolyte solution, wherein the non-aqueous electrolyte solution is described in any one of <1> to <6>. Non-aqueous electrolyte battery, which is a non-aqueous electrolyte solution.

According to the present invention, it is possible to obtain a non-aqueous electrolyte solution excellent in suppressing an increase in internal resistance of a battery in high temperature storage and a non-aqueous electrolyte battery in which an increase in internal resistance is suppressed in high temperature storage.

Hereinafter, embodiments of the present invention will be described in detail. The following embodiments are examples (representative examples) 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. Non-aqueous electrolyte solution>
The non-aqueous electrolyte solution according to the present invention is a compound having at least one Si—O structure selected from the compound represented by the general formula (A) and the compound represented by the general formula (B) described below. (Hereinafter, it is also referred to as "a compound having a Si—O structure represented by the general formula (A) or the general formula (B)") and contains a compound represented by the general formula (α).
A compound having a Si—O structure represented by the general formula (A) or the general formula (B) and a compound in which a Si atom and a benzene ring are bonded via an oxygen atom or a carbon atom represented by the general formula (α). The mechanism for suppressing the internal resistance of the battery during high-temperature storage by using a non-aqueous electrolyte solution containing benzene is not clear, but it is presumed as follows.

The compound represented by the general formula (A) or the general formula (B) has a polar structure (-Si-O-) and a non-polar structure (for example, -SiR ¹ R ² R ³ ) in the molecule. By interacting these structural parts with the aromatic ring, silyl group, silyloxy group, etc. of the compound represented by the general formula (α), a complex film is formed on the surface of the positive electrode active material and / or the negative electrode active material. It is presumed to be done. Since this composite film has high insulating properties at high temperatures, it is presumed that the increase in internal resistance of the battery is suppressed by suppressing the excessive decomposition reaction of the electrolytic solution during storage at high temperatures.

<1-1. Compound with Si—O structure>
The non-aqueous electrolyte solution according to the embodiment of the present invention has at least one Si—O structure selected from the compound represented by the following general formula (A) and the compound represented by the general formula (B). It is characterized by containing a compound.

（式（Ａ）中、Ｒ^１〜Ｒ^３は、それぞれ独立に、水素原子、ハロゲン原子、置換基を有し
ていてもよい炭素数１〜１２の炭化水素基、又は置換基を有していてもよい炭素数１〜１２のアルコキシ基を示し、Ｘは置換基を有していてもよい炭素数１〜１２の炭化水素基、又は−ＳｉＲ^ｏＲ^ｐＲ^ｑで表されるシリル基を示す。Ｒ^ｏ〜Ｒ^ｑは、それぞれ独立に、水素原子、ハロゲン原子、置換基を有していてもよい炭素数１〜１２の炭化水素基、又は置換基を有していてもよい炭素数１〜１２のアルコキシ基を示す。） <1-1-1. Compound represented by general formula (A)>

(In the formula (A), R ^{1 to} R ³ each independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a substituent. It represents an alkoxy group having 1 to 12 carbon atoms, and X is a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a silyl group represented by ^{−SiR o} R ^p R ^q. R ^{o to} R ^q each independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a hydrocarbon group which may have a substituent. 1 to 12 alkoxy groups are shown.)

^{R 1 to} R ^{3 according} to the general formula (A) each independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a substituent. Indicates an alkoxy group having 1 to 12 carbon atoms which may be used. Among them, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent or an alkoxy group having 1 to 12 carbon atoms which may have a substituent is preferable, and a substituent is particularly preferable. It is a hydrocarbon group having 1 to 12 carbon atoms which may have a group or an alkoxy group having 1 to 12 carbon atoms which may have a substituent. When the hydrocarbon group has a substituent, the number of carbons contained in the substituent is not included in the number of carbon atoms.
Further, ^{at least one of R 1 to} R ³ is a hydrocarbon group having a carbon-carbon unsaturated bond and having 2 to 12 carbon atoms, and the compound represented by the general formula (A) is suitable for the electrode surface. It is preferable from the viewpoint that it tends to be localized. Examples of the hydrocarbon group having 2 to 12 carbon atoms having a carbon-carbon unsaturated bond include an alkenyl group having 2 to 12 carbon atoms, an alkynyl group having 2 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms, which will be described later. Among them, an alkenyl group having 2 to 12 carbon atoms or an alkynyl group having 2 to 12 carbon atoms is preferable from the viewpoint that the compound represented by the general formula (A) tends to be more preferably localized on the electrode surface. .. Particularly preferred is an alkenyl group having 2 to 12 carbon atoms.
^{R 1 to} R ^{3 according} to the general formula (A) may be the same or different, but it is preferable that at least two or more of them are the same in that the compound can be easily synthesized, and all three are the same. Is more preferable from the above-mentioned viewpoint.
Examples of the halogen atom include a fluorine atom, a chlorine atom and a bromine atom. Preferably, it is a fluorine atom in terms of having few electrochemical side reactions.
The hydrocarbon group having 1 to 12 carbon atoms is preferably a hydrocarbon group having 1 to 6 carbon atoms, and particularly preferably a hydrocarbon group having 1 to 4 carbon atoms.
Specific examples of the hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group and an aryl group.
Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, a hexyl group, a heptyl group, an octyl group and a nonyl group. , Decyl group and the like. Of these, methyl group, ethyl group, n-propyl group, n-butyl group, tert-butyl group, n-pentyl group and hexyl group are preferable, and methyl group, ethyl group, n-propyl group and n-butyl group are more preferable. Groups, tert-butyl group, n-pentyl group, particularly preferably methyl group, ethyl group, n-butyl group, tert-butyl group can be mentioned. The above-mentioned alkyl group is preferable because the compound represented by the general formula (A) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.

Specific examples of the alkenyl group include a vinyl group, an allyl group, a metallicyl group, a 2-butenyl group, a 3-methyl2-butenyl group, a 3-butenyl group, a 4-pentenyl group and the like. Of these, a vinyl group, an allyl group, a metalyl group, a 2-butenyl group, more preferably a vinyl group, an allyl group, a metalyl group, and particularly preferably a vinyl group or an allyl group can be mentioned. The above-mentioned alkenyl group is preferable because the compound represented by the general formula (A) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.

Specific examples of the alkynyl group include an ethynyl group, a 2-propynyl group, a 2-butynyl group, a 3-butynyl group, a 4-pentynyl group, a 5-hexynyl group and the like. Of these, ethynyl group, 2-propynyl group, 2-butynyl group, 3-butynyl group are more preferable, 2-propynyl group and 3-butynyl group are more preferable, and 2-propynyl group is particularly preferable. The above-mentioned alkynyl group is preferable because the compound represented by the general formula (A) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.

Specific examples of the aryl group include a phenyl group, a tolyl group, a benzyl group, a phenethyl group and the like. Of these, a phenyl group is preferable from the viewpoint that the compound according to the general formula (A) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.
The alkoxy group having 1 to 12 carbon atoms is preferably an alkoxy group having 1 to 6 carbon atoms, and particularly preferably an alkoxy group having 1 to 4 carbon atoms.
Specific examples of the alkoxy group having 1 to 12 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, an isopropoxy group, a methoxyethoxy group and the like. Among them, the methoxy group and the ethoxy group are preferable in that the compound represented by the general formula (A) has less steric hindrance and is suitably concentrated on the surface of the active material.

Here, examples of the substituent include a cyano group, an isocyanato group, an acyl group (-(C = O) -R ^a ), an acyloxy group (-O (C = O) -R ^a ), and an alkoxycarbonyl group (-(). C = O) O-R ^a ), sulfonyl group (-SO _2- R ^a ), sulfonyloxy group (-O (SO ₂ ) -R ^a ), alkoxysulfonyl group (-(SO ₂ ) -O-R ^a) ), Halkoxysulfonyloxy group (-O- (SO ₂ ) -O-R ^a ), alkoxycarbonyloxy group (-O- (C = O) -O-R ^a ), ether group (-O-R ^a ) , Halogen (preferably fluorine), trifluoromethyl group and the like. ^Ra has an alkyl group having 1 to 10 carbon atoms, an alkylene group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl having 2 to 10 carbon atoms. Indicates a group. When ^Ra is an alkylene group, it may be bonded to a part of the substituted hydrocarbon group to form a ring.
Among the above substituents, a cyano group, an isocyanato group, an acyloxy group (-O (C = O) -R a), halogen (preferably fluorine), trifluoromethyl group, more preferably, isocyanato A group, an acyloxy group (-O (C = O) -R ^a ), a halogen (preferably fluorine), a trifluoromethyl group, and particularly preferably an acyloxy group (-O (C = O) -R ^a ). , Halogen (preferably fluorine), trifluoromethyl group.
X according to the general formula (A) represents a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent or a silyl group represented by ^{−SiR o} R ^p R ^q.
Here, examples of the hydrocarbon group having 1 to 12 carbon atoms include those described in ^{R 1 to} R ^{3.
R o to} R ^q in the silyl group represented by −SiR ^o R ^p R ^q are hydrocarbon groups having 1 to 12 carbon atoms, which may independently have a hydrogen atom, a halogen atom, and a substituent. Alternatively, an alkoxy group having 1 to 12 carbon atoms which may have a substituent is shown. Of these, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent or an alkoxy group having 1 to 12 carbon atoms which may have a substituent is preferable, and a substituent is particularly preferable. It is a hydrocarbon group having 1 to 12 carbon atoms which may have a group.
Here, the halogen atom, the hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, and the alkoxy group having 1 to 12 carbon atoms which may have a substituent are all R ^{1 to R.} It is synonymous with what is specified in ^3. The same applies to the preferred embodiment.
-SiR ^o R ^p Specific examples of the silyl group represented by R ^q _{is, -Si (CH 3) 3,} -Si (CH 3) 2 (C 2 H 5), - Si (CH 3) 2 (CH = CH ₂ ), -Si (CH ₃ ) ₂ (CH ₂ CH ₂ CH ₃ ), -Si (CH ₃ ) ₂ (CH ₂ CH = CH ₂ ), -Si (CH ₃ ) ₂ [CH (CH ₃ ) ₂ ], -Si (CH ₃ ) ₂ [(CH ₂ ) ₃ CH ₃ )], -Si (CH ₃ ) ₂ [CH ₂ CH (CH ₃ ) ₂ ], -Si (CH ₃ ) ₂ [C (CH) ₃ ) ₃ ], _{-Si (CH 3} ) ₂ (C ₆ H ₅ ) _{, -Si (CH 3} ) (C ₆ H ₅ ) ₂ , -Si (C ₆ H ₅ ) ₃ , -Si (C ₂ H ₅₎ ) ₃ , -Si (CH = CH ₂ ) ₃ , -Si (CH ₂ CH ₂ CH ₃ ) ₃ , -Si [CH (CH ₃ ) ₂ ] ₃ , -Si (CH ₂ CH = CH ₂ ) ₃ ,- Si (CH ₃ )
_{(C 6 H 5) (CH} = CH 2), - Si (C 6 H 5) 2 (CH = CH 2) or -Si _{(CF 3)} 3 and the like. Among _{them, -Si (CH 3) 3,} -Si (CH 3) 2 (CH = CH 2), - Si (CH 3) 2 (CH 2 CH = CH 2), - Si (C 2 H 5) 3 , -Si (CH ₃ ) (C ₆ H ₅ ) (CH = CH ₂ ) _{, -Si (C 6} H ₅ ) ₂ (CH = CH ₂ ) are preferable, and -Si (CH ₃ ) ₂ (CH = CH ₂₎ ), -Si (CH ₃ ) ₂ (CH ₂ CH = CH ₂ ) is particularly preferable.

（式（Ｂ）中、Ｒ^４〜Ｒ^５は、それぞれ独立に、水素原子、ハロゲン原子、置換基を有していてもよい炭素数１〜１２の炭化水素基、又は置換基を有していてもよい炭素数１〜１２のアルコキシ基を示し、ｋは３〜６の整数を示す。） <1-1-2. Compound represented by general formula (B)>

(In the formula (B), R ^{4 to} R ⁵ each independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a substituent. It indicates an alkoxy group having 1 to 12 carbon atoms which may be used, and k indicates an integer of 3 to 6).

^{R 4 to} R ^{5 according} to the general formula (B) each independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a substituent. It represents an alkoxy group having 1 to 12 carbon atoms which may be used.
^{R 4 to} R ^{5 according} to the general formula (B) may be the same or different, but it is preferable that both of them are the same in that the compound can be easily synthesized.
Here, the halogen atom, the hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, and the alkoxy group having 1 to 12 carbon atoms which may have a substituent are all R ^{1 to R.} It is synonymous with what is specified in ^3.

In the formula (B), k is usually an integer of 3 to 6, and k is preferably 3 or 4.

In one embodiment of the present invention, a compound having at least one Si—O structure selected from the compound represented by the general formula (A) and the compound represented by the general formula (B) is used. Specific examples thereof include compounds having the following structures.

(Specific example of the compound represented by the general formula (A))

(Specific example of the compound represented by the general formula (B))

Examples of the compound having a Si—O structure represented by the general formula (A) or (B) preferably include the following compounds.

More preferably, the following compounds are mentioned as the compound having a Si—O structure represented by the general formula (A) or (B).

Examples of the compound having a Si—O structure represented by the general formula (A) or (B) include the following compounds.

The total content of the compounds having the Si—O structure represented by the general formula (A) or (B) with respect to the total amount of the non-aqueous electrolyte solution according to the embodiment of the present invention is usually 0.001% by mass or more. Yes, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.2% by mass or more, and usually 10% by mass or less, preferably 8% by mass or less, more preferably. Is 6.0% by mass or less, more preferably 4.0% by mass or less, particularly preferably 3.0% by mass or less, particularly preferably 2.5% by mass or less, and most preferably 2.0% by mass or less. Is.
If the total content of the compound having the Si—O structure represented by the general formula (A) or (B) with respect to the total amount of the non-aqueous electrolyte solution is within the above range, concentration of the compound in the active material is preferable. As the process progresses, it becomes possible to manufacture a battery in which the amount of gas generated during initial conditioning is small.
The content of the compound having a Si—O structure represented by the general formula (A) or (B) can be calculated by nuclear magnetic resonance spectroscopy (NMR).

（式（α）中、Ｒ^６〜Ｒ^８は、それぞれ独立に、水素原子、ハロゲン原子、置換基を有していてもよい炭素数１〜１２の炭化水素基、又は置換基を有していてもよい炭素数１〜１２のアルコキシ基を示す。Ｒ^９〜Ｒ^１３は、それぞれ独立に、水素原子、ハロゲン原子、置換基を有していてもよい炭素数１〜１２の炭化水素基、置換基を有していてもよい炭素数１〜１２のアルコキシ基、又は−ＯＳｉＲ^ｒＲ^ｓＲ^ｔで表されるシリルオキシ基を示す。Ｒ^ｒ〜Ｒ^ｔは、それぞれ独立に、置換基を有していてもよい炭素数１〜１２の炭化水素基、又は置換基を有していてもよい炭素数１〜１２のアルコキシ基を示す。Ｙは単結合、酸素原子、又は置換基を有していてもよい炭素数１〜６のアルキレン基を示す。） <1-2. Compound represented by general formula (α)>
The non-aqueous electrolyte solution according to the embodiment of the present invention is characterized by containing a compound represented by the general formula (α).

(In the formula (α), R ^{6 to} R ⁸ each independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a substituent. The alkoxy groups having 1 to 12 carbon atoms may be shown. R ^{9 to} R ¹³ are hydrocarbon groups having 1 to 12 carbon atoms which may independently have a hydrogen atom, a halogen atom and a substituent. An alkoxy group having 1 to 12 carbon atoms which may have a substituent or a silyloxy group represented by ^{−OSiR r} R ^s R ^{t. R r to} R ^t each independently have a substituent. Indicates a hydrocarbon group having 1 to 12 carbon atoms which may be used, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent. Y has a single bond, an oxygen atom, or a substituent. Indicates an alkylene group having 1 to 6 carbon atoms which may be present.)

^{R 6 to} R ^{8 according} to the general formula (α) each independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a substituent. Indicates an alkoxy group having 1 to 12 carbon atoms which may be used. Among them, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent and an alkoxy group having 1 to 12 carbon atoms which may have a substituent are preferable, and a substituent is particularly preferable. It is a hydrocarbon group having 1 to 12 carbon atoms which may be used. When the hydrocarbon group has a substituent, the number of carbons contained in the substituent is not included in this number of carbon atoms.
Further, ^{at least one of R 6 to} R ⁸ is an alkyl group having 1 to 12 carbon atoms, and the compound represented by the general formula (α) is represented by the general formula (A) or the general formula (B). It is preferable from the viewpoint of preferably interacting with a compound having a Si—O structure. Particularly preferably ^{, all of R 6 to} R ⁸ are alkyl groups having 1 to 12 carbon atoms.
^{R 6 to} R ⁸ represented by the general formula (α) may be the same or different, but preferably at least two or more are the same in terms of easy compound synthesis, and three are preferable. It is more preferable that they are the same as the above-mentioned viewpoints.
Examples of the halogen atom include a fluorine atom, a chlorine atom and a bromine atom. Preferably, it is a fluorine atom in terms of having few electrochemical side reactions.
The hydrocarbon group having 1 to 12 carbon atoms is preferably a hydrocarbon group having 1 to 6 carbon atoms, and particularly preferably a hydrocarbon group having 1 to 4 carbon atoms.
The alkoxy group having 1 to 12 carbon atoms is preferably an alkoxy group having 1 to 6 carbon atoms, and particularly preferably an alkoxy group having 1 to 4 carbon atoms.

Specific examples of the hydrocarbon group include an alkyl group, an alkenyl group, an alkynyl group and an aryl group.
Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a tert-butyl group, an n-pentyl group, a hexyl group, a heptyl group, an octyl group and a nonyl group. , Decyl group and the like. Of these, methyl group, ethyl group, n-propyl group, n-butyl group, tert-butyl group, n-pentyl group and hexyl group are preferable, and methyl group, ethyl group, n-propyl group and n-butyl group are more preferable. Groups, tert-butyl group, n-pentyl group, particularly preferably methyl group, ethyl group, n-butyl group, tert-butyl group can be mentioned. The above-mentioned alkyl group is preferable because the compound represented by the general formula (α) tends to be localized near the surface of the positive electrode active material and / or the negative electrode active material.

Specific examples of the alkenyl group include a vinyl group, an allyl group, a metallicyl group, a 2-butenyl group, a 3-methyl2-butenyl group, a 3-butenyl group, a 4-pentenyl group and the like. Of these, a vinyl group, an allyl group, a metalyl group, a 2-butenyl group, more preferably a vinyl group, an allyl group, a metalyl group, and particularly preferably a vinyl group or an allyl group can be mentioned. The above-mentioned alkenyl group is preferable because it tends to interact favorably with the compound having the Si—O structure represented by the general formula (A) or the general formula (B).

Specific examples of the alkynyl group include an ethynyl group, a 2-propynyl group, a 2-butynyl group, a 3-butynyl group, a 4-pentynyl group, a 5-hexynyl group and the like. Of these, ethynyl group, 2-propynyl group, 2-butynyl group, 3-butynyl group are more preferable, 2-propynyl group and 3-butynyl group are more preferable, and 2-propynyl group is particularly preferable. The above-mentioned alkynyl group is preferable because it tends to interact favorably with a compound having a Si—O structure represented by the general formula (A) or the general formula (B).

Specific examples of the aryl group include a phenyl group, a tolyl group, a benzyl group, a phenethyl group and the like. Of these, a phenyl group is preferable from the viewpoint of preferably interacting with a compound having a Si—O structure represented by the general formula (A) or the general formula (B).
The alkoxy group having 1 to 12 carbon atoms is preferably an alkoxy group having 1 to 6 carbon atoms, and particularly preferably an alkoxy group having 1 to 4 carbon atoms.
Specific examples of the alkoxy group having 1 to 12 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, an isopropoxy group, a methoxyethoxy group and the like. Of these, the methoxy group and the ethoxy group are preferable because they have less steric hindrance to the compound and are suitably concentrated on the surface of the active material.
Here, the substituents include a cyano group, an isocyanato group, an acyl group (-(C = O) -R ^b ), an acyloxy group (-O (C = O) -R ^b ), and an alkoxycarbonyl group (-(). C = O) ^{OR b} ), sulfonyl group (-SO _2- R ^b ), sulfonyloxy group (-O (SO ₂ ) -R ^b ), alkoxysulfonyl group (-(SO ₂ ) -OR ^b) ), Halkoxysulfonyloxy group (-O- (SO ₂ ) -OR ^b ), alkoxycarbonyloxy group (-O- (C = O) -OR ^b ), ether group (-O-R ^b ) , Acrylic group, methacryl group, halogen (preferably fluorine), trifluoromethyl group and the like. R ^b is an alkyl group having 1 to 10 carbon atoms, an alkylene group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkynyl having 2 to 10 carbon atoms. Indicates a group. When R ^b is an alkylene group, it may be bonded to a part of the substituted hydrocarbon group to form a ring.
Among these substituents, a cyano group, an isocyanato group, an acyloxy group (-O (C = O) -R ^b ), a halogen (preferably fluorine), and a trifluoromethyl group are preferable, and isocyanato is more preferable. A group, an acyloxy group (-O (C = O) -R ^b ), a halogen (preferably fluorine), a trifluoromethyl group, and particularly preferably an acyloxy group (-O (C = O) -R ^b ). , Halogen (preferably fluorine), trifluoromethyl group.

^{R 9 to} R ^{13 according} to the general formula (α) each independently have a hydrocarbon atom, a halogen atom, and a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent and a substituent. A good alkoxy group having 1 to 12 carbon atoms or a silyloxy group represented by ^{−OSiR r} R ^s R ^{t is shown.
R 9 to} R ^{13 according} to the general formula (α) are represented by a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or −OSiR ^r R ^s R ^t . The silyloxy group to be used is preferable, and particularly preferably a hydrogen atom or a silyloxy group represented by ^{−OSiR r} R ^s R ^t. When the hydrocarbon group has a substituent, the number of carbons contained in the substituent is not included in this number of carbon atoms.
^{R 9 to} R ^{13 according} to the general formula (α) may be the same or different, but the fact that they are all hydrogen atoms has less steric hindrance to the compound (α) and is the general formula (A) or the general formula (B). ) Is preferable in that it can interact favorably with the compound represented by).
The ^{halogen atom specified in R 9 to} R ¹³ , the hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, and the alkoxy group having 1 to 12 carbon atoms which may have a substituent are R. defines at ⁶ to R ⁸ is as defined above.
^{R r to} R ^t in the silyloxy group represented by −OSiR ^r R ^s R ^t each independently has a hydrocarbon group having 1 to 12 carbon atoms or a substituent which may have a substituent. Indicates an alkoxy group having 1 to 12 carbon atoms which may be present. Among them, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent is preferable, a hydrocarbon group having 1 to 6 carbon atoms is more preferable, and a hydrocarbon group having 1 to 4 carbon atoms is particularly preferable. It is a hydrocarbon group of. Here, both the hydrocarbon group having 1 to 12 carbon atoms which may have a substituent and the alkoxy group having 1 to 12 carbon atoms which may have a substituent are R ^{9 to} R ¹³ . It is synonymous with what is specified. -OSiR ^r R ^s Specific examples of the silyloxy group represented by R ^t _{is, -OSi (CH 3) 3,} -OSi (CH 3) 2 (C 2 H 5), - OSi (CH 3) 2 (CH = CH ₂ ), -OSI (CH ₃ ) ₂ (CH ₂ CH ₂ CH ₃ ), -OSI (CH ₃ ) ₂ (CH ₂ CH = CH ₂ ), -OSI (CH ₃ ) ₂ [CH (CH ₃ ) ₂ ], -OSI (CH ₃ ) ₂ [(CH ₂ ) ₃ CH ₃ )], -OSI (CH ₃ ) ₂ [CH ₂ CH (CH ₃ ) ₂ ], -OSI (CH ₃ ) ₂ [C (CH) ₃ ) ₃ ], -OSI (CH ₃ ) ₂ (C ₆ H ₅ ), -OSI (CH ₃ ) (C ₆ H ₅ ) ₂ , -OSI (C ₆ H ₅ ) ₃ , -OSI (C ₂ H ₅₎ ) ₃ , -OSI (CH = CH ₂ ) ₃ , -OSI (CH ₂ CH ₂ CH ₃ ) ₃ , -OSI [CH (CH ₃ ) ₂ ] ₃ , -OSI (CH ₂ CH = CH ₂ ) ₃ ,- Examples thereof include OSI (CH ₃ ) (C ₆ H ₅ ) (CH = CH ₂ ), -OSI (C ₆ H ₅ ) ₂ (CH = CH ₂ ), and -OSI (CF ₃ ) ₃ . Among them, -OSI (CH ₃ ) ₃ , -OSI (CH ₃ ) ₂ (CH = CH ₂ ), -OSI (CH ₃ ) ₂ (CH ₂ CH = CH ₂ ), -OSI (C ₂ H ₅ ) ₃ , -OSI (CH ₃ ) (C ₆ H ₅ ) (CH = CH ₂ ), -OSI (C ₆ H ₅ ) ₂ (CH = CH ₂ ) are preferred, and -OSi (CH ₃ ) ₃ is particularly preferred.
Here, the substituents are all synonymous with those specified by ^{R 6 to} R ^8.
Y according to the general formula (α) represents an alkylene group having 1 to 6 carbon atoms which may have a single bond, an oxygen atom, or a substituent. Here, the substituents are all synonymous with those specified by ^{R 6 to} R ^8.
The alkylene group having 1 to 6 carbon atoms is preferably an alkylene group having 1 to 4 carbon atoms, and particularly preferably an alkylene group having 1 to 2 carbon atoms. These carbon chain lengths have less steric hindrance and are preferable from the viewpoint of preferably interacting with a compound having a Si—O structure represented by the general formula (A) or the general formula (B).
When Y is not an oxygen atom or an alkylene group having 1 to 6 carbon atoms which may have a substituent, the aromatic ring and silicon form a direct bond, that is, a single bond.

Specific examples of the compound represented by the general formula (α) used in the present invention include compounds having the following structures.

The following compounds are preferably mentioned as the compound represented by the general formula (α).

More preferably, the following compounds are mentioned as the compound represented by the general formula (α).

As the compound represented by the general formula (α), the following compounds are particularly preferable.

The following compounds are most preferably mentioned as the compound represented by the general formula (α).

The total content of the compound represented by the general formula (α) with respect to the total amount of the non-aqueous electrolyte solution according to the embodiment of the present invention is not particularly limited, but is preferably 0.01 mass ppm or more. It is more preferably 0.1% by mass or more, further preferably 1.0% by mass or more, particularly preferably 10% by mass or more, and preferably less than 0.5% by mass, more preferably 0.4% by mass. % Or less, more preferably 0.3% by mass or less, particularly still more preferably 0.2% by mass or less, and particularly preferably 0.1% by mass or less.
If the total content of the compound represented by the general formula (α) with respect to the total amount of the non-aqueous electrolyte solution is within the above range, the formation of the composite film proceeds optimally, and the internal resistance of the battery during high temperature storage increases. It is possible to manufacture a small number of batteries.
The content of the compound represented by the general formula (α) can be calculated by nuclear magnetic resonance spectroscopy (NMR).

The ratio of the mass of the content of the compound represented by the general formula (A) or the general formula (B) to the content of the compound represented by the general formula (α) in the non-aqueous electrolyte solution is not particularly limited. no but generally 1.0 or more, preferably 2.0 or more, particularly preferably 3.0 or more, whereas, typically 1.0 × 10 ⁴ or less, preferably 7.0 × 10 ³ or less, more preferably 4.0 x 10 ³ or less,
More preferably 2.0 × 10 ³ or less, preferably 1.0 × 10 ³ or less, deliberately particularly preferably 5.0 × 10 ² or less. When both the compound represented by the general formula (A) and the compound represented by the general formula (B) are included, the above ratio is the general formula (A) with respect to the content of the compound represented by the general formula (α). ) And the ratio of the total content of the compounds represented by the general formula (B).
The method for incorporating the compound represented by the general formula (α) and the compound having the Si—O structure represented by the general formula (A) or (B) into the electrolytic solution of the present invention is not particularly limited. .. In addition to the method of directly adding the compound to the electrolytic solution, a method of generating the compound in a battery or an electrolytic solution can be mentioned.

The content of the compound in the present invention means the content at the time of producing the non-aqueous electrolyte solution, at the time of injecting the non-aqueous electrolyte solution into the battery, or at the time of shipment as the battery.

<1-3. Electrolyte>
The non-aqueous electrolyte solution of the present embodiment usually contains an electrolyte as a component thereof, like a general non-aqueous electrolyte solution. The electrolyte used in the non-aqueous electrolyte solution of the present embodiment is not particularly limited, and known electrolytes can be used. Hereinafter, specific examples of the electrolyte will be described in detail.

<1-3-1. Lithium salt>
As the electrolyte in the non-aqueous electrolyte solution of the present embodiment, a lithium salt is usually used. The lithium salt is not particularly limited as long as it is known to be used for this purpose, and any one or more lithium salts can be used, and specific examples thereof include the following.

For example, inorganic lithium salts _{such as LiBF 4} , LiClO ₄ , _{LiAlF 4} , LiSbF ₆ , LiTaF ₆ , LiWF _7;
Lithium fluorophosphates such as LiPF ₆ and LiPO ₂ F _2;
Lithium tungstic acid salts such as LiWOF _5;
Lithium carboxylic acid salts such as CF ₃ CO _{2 Li;}
Lithium sulfonic acid salts such as CH ₃ SO _{3 Li;}
Lithium imide salts such as LiN (FSO ₂ ) ₂ and LiN (CF ₃ SO ₂ ) _2;
LiC (FSO ₂ ) ₃ etc. lithium methide salts;
Lithium oxalate salts such as lithium difluorooxalate borate;
In addition, fluorine-containing organic lithium salts such as _{LiPF 4} (CF ₃ ) _2;
And so on.

Inorganic lithium salts, lithium fluorophosphates, lithium sulfonic acid salts, lithium imide from the viewpoint of further enhancing the effect of improving charge / discharge rate characteristics and impedance characteristics in addition to improving the charge storage characteristics in a high temperature environment obtained by the present invention. Those selected from salts and lithium oxalate salts are preferable, and inorganic lithium salts and lithium imide salts are more preferable from the viewpoint of improving charge / discharge characteristics.

The total concentration of these electrolytes in the non-aqueous electrolyte solution is not particularly limited, but is usually 8% by mass or more, preferably 8.5% by mass or more, more preferably 9% by mass, based on the total amount of the non-aqueous electrolyte solution. % Or more. The upper limit thereof is usually 18% by mass or less, preferably 17% by mass or less, and more preferably 16% by mass or less. When the total concentration of the electrolyte is within the above range, the electrical conductivity becomes appropriate for battery operation, so that sufficient output characteristics tend to be obtained.

<1-4. Non-aqueous solvent>
Like a general non-aqueous electrolyte solution, the non-aqueous electrolyte solution of the present embodiment 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. Examples of the organic solvent include saturated cyclic carbonates, chain carbonates, carboxylic acid esters, ether compounds, sulfone compounds and the like. Although not particularly limited to these, a saturated cyclic carbonate, a chain carbonate or a carboxylic acid ester is preferable, and a saturated cyclic carbonate or a chain carbonate is more preferable. These can be used individually by 1 type or in combination of 2 or more types. As a combination of two or more non-aqueous solvents, a combination of two or more selected from the group consisting of saturated cyclic carbonate, chain carbonate, and carboxylic acid ester is preferable, and a combination of saturated cyclic carbonate or chain carbonate is more preferable. ..

<1-4-1. Saturated cyclic carbonate>
Examples of the saturated cyclic carbonate usually include those having an alkylene group having 2 to 4 carbon atoms, and a saturated cyclic carbonate having 2 to 3 carbon atoms is preferably used from the viewpoint of improving battery characteristics resulting from an improvement in the degree of lithium ion dissociation. .. Further, the saturated cyclic carbonate may be a cyclic carbonate having a fluorine atom such as monofluoroethylene carbonate.

Examples of the saturated cyclic carbonate include ethylene carbonate, propylene carbonate, butylene carbonate and the like. Of these, ethylene carbonate and propylene carbonate are preferable, and ethylene carbonate, which is difficult to be oxidized and reduced, is more preferable. As the saturated 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 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 based on the total amount of the solvent in the non-aqueous electrolyte solution. It is usually 3% by volume or more, preferably 5% by volume or more. By setting this range, the decrease in electrical conductivity due to the decrease in the dielectric constant of the non-aqueous electrolyte solution is avoided, and the large current discharge characteristics, stability with respect to the negative electrode, and cycle characteristics of the non-aqueous electrolyte battery are in a good range. It becomes easy to do. The upper limit is usually 90% by volume or less, preferably 85% by volume or less, and more preferably 80% by volume or less. Within this range, the oxidation / reduction resistance of the non-aqueous electrolyte solution tends to be improved, and the stability during high-temperature storage tends to be improved.
The volume in the present invention means a volume at 25 ° C. and 1 atm.

<1-4-2. Chain carbonate>
As the chain carbonate, one having 3 to 7 carbon atoms is usually used, and in order to adjust the viscosity of the electrolytic solution in an appropriate range, a chain carbonate having 3 to 5 carbon atoms is preferably used.

Specifically, the chain carbonates include dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propylisopropyl carbonate, ethylmethyl carbonate, methyl-n-propyl carbonate, n-butylmethyl carbonate, and the like. Examples thereof include isobutylmethyl carbonate, t-butylmethyl carbonate, ethyl-n-propyl carbonate, n-butylethyl carbonate, isobutylethyl carbonate, t-butylethyl carbonate and the like.

Among them, dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, diisopropyl carbonate, n-propylisopropyl carbonate, ethylmethyl carbonate and methyl-n-propyl carbonate are preferable, and dimethyl carbonate, diethyl carbonate and ethylmethyl carbonate are particularly preferable. be.

Further, chain carbonates having a fluorine atom (hereinafter, may be abbreviated as "fluorinated chain carbonate") 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.

Examples of the fluorinated dimethyl carbonate derivative include fluoromethyl methyl carbonate, difluoromethyl methyl carbonate, trifluoromethyl methyl carbonate, bis (fluoromethyl) carbonate, bis (difluoro) methyl carbonate, bis (trifluoromethyl) carbonate and the like.

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 Examples thereof include 2-trifluoroethyl-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% by volume or more, preferably 20% by volume or more, and more preferably 25% by volume or more with respect to the total amount of the solvent of the non-aqueous electrolyte solution. 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 can be set in an appropriate range, the decrease in ionic conductivity can be suppressed, and the output characteristics of the non-aqueous electrolyte battery can be easily set in a good range. Become. When two or more kinds of chain carbonates are used in combination, the total amount of chain carbonates may satisfy the above range.

Further, by combining ethylene carbonate with a specific chain carbonate at 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. It is usually 15% by volume or more, preferably 20% by volume or more, and usually 45% by volume or less, preferably 40% by volume or less with respect to the total amount of the solvent, and the content of dimethyl carbonate is the total amount of the solvent of the non-aqueous electrolyte solution. On the other hand, it 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, and the content of ethylmethyl carbonate is usually 20% by volume or more, preferably 30% by volume. Above, usually 50% by volume or less, preferably 45% by volume or less. By setting the contents of ethylene carbonate, dimethyl carbonate and ethyl methyl carbonate within the above range, high temperature stability is excellent and gas generation tends to be suppressed.

<1-4-3. 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.

As the ether compound, 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 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, more preferably 2% by volume or more in 100% by volume of the non-aqueous solvent. Is 3% by volume or more, and usually 30% by volume or less, preferably 25% by volume or less, and more preferably 20% by volume or less. When two or more kinds of ether compounds are used in combination, the total amount of the ether compounds may satisfy the above range. 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 due to 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.

<1-4-4. Sulfone compounds>
The sulfone compound is not particularly limited even if it is a cyclic sulfone or a chain sulfone, but in the case of a cyclic sulfone, the number of carbon atoms is usually 3 to 6, preferably 3 to 5, and in the case of a chain sulfone. , Usually, a compound having 2 to 6 carbon atoms, preferably 2 to 5 carbon atoms is preferable. The number of sulfonyl groups in one molecule of the sulfone compound is not particularly limited, but is usually 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, and 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.

As the sulfone compound, 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 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. It is 5% by volume or more, more preferably 1% by volume or more, and usually 40% by volume or less, preferably 35% by volume or less, more preferably 30% by volume or less. When two or more kinds of sulfone compounds are used in combination, the total amount of the sulfone compounds may satisfy the above range. When the content of the sulfone compound is within the above range, an electrolytic solution having excellent high temperature storage stability tends to be obtained.

<1-4-5. Carboxylate ester>
The carboxylic acid ester is preferably a chain carboxylic acid ester, and more preferably a saturated chain carboxylic acid ester. The total carbon number of the carboxylic acid ester is usually 3 to 7, and a carboxylic acid ester of 3 to 5 is preferably used from the viewpoint of improving the battery characteristics resulting from the improvement of the output characteristics.

Examples of the carboxylic acid ester include saturated chain carboxylic acid esters such as methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl pivalate, and ethyl pivalate, methyl acrylate, ethyl acrylate, methyl methacrylate, and methacrylic acid. Examples thereof include unsaturated chain carboxylic acid esters such as ethyl. Of these, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl pivalate, and ethyl pivalate are preferable, and methyl acetate, ethyl acetate, methyl propionate, and ethyl propionate are more preferable from the viewpoint of improving output characteristics. As the carboxylic acid ester, 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 carboxylic acid ester is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but the lower limit is usually 3% by volume or more, preferably 5 by volume, based on the total amount of the solvent of the non-aqueous electrolyte solution. It is more than% by volume. By setting the content of the carboxylic acid ester in this range, it is possible to avoid a decrease in electrical conductivity due to a decrease in the dielectric constant of the non-aqueous electrolyte solution, and the large current discharge characteristics of the non-aqueous electrolyte battery and stability with respect to the negative electrode. , It becomes easy to set the cycle characteristics in a good 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. Within this range, the oxidation / reduction resistance of the non-aqueous electrolyte solution tends to be improved, and the stability during high-temperature storage tends to be improved.
The volume% in the present invention means the volume at 25 ° C. and 1 atm.

<1-5. Fluorinated salt>
In the present specification, the fluorinated salt is not particularly limited, but since it has a highly desorbable fluorine atom in its structure, for example, when combined with a cyclic aliphatic acid anhydride, it is a cyclic aliphatic. Difluorophosphates, fluorosulfonates, fluoroboron salts and fluoroimide salts can be used because the acid anhydride can react favorably with the anion (nucleophilic species) produced by the reduction reaction to form a complex film. preferable. Fluoroborone salt, fluorosulfonate, and difluorophosphate are more preferable, and fluoroboron salt and difluorophosphate are more preferable because the desorption of fluorine atoms is particularly high and the reaction with the nucleophilic species proceeds favorably. Especially preferable. Hereinafter, these various salts will be described.

(Difluorophosphate)
The counter cation of difluorophosphate is not particularly limited, but lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, barium, and NR ¹³ R ¹⁴ R ¹⁵ R ¹⁶ (in the formula, R ^{13 to} R ^16). Each independently represents a hydrogen atom or an organic group having 1 to 12 carbon atoms.) Ammonium and the like represented by) can be mentioned as an example.

The ^{organic group having 1 to 12 carbon atoms represented by R 13 to} R ¹⁶ of the ammonium is not particularly limited, but is substituted with, for example, an alkyl group which may be substituted with a halogen atom, a halogen atom or an alkyl group. Examples thereof include a cycloalkyl group which may be present, an aryl group which may be substituted with a halogen atom or an alkyl group, a nitrogen atom-containing heterocyclic group which may have a substituent, and the like. Among ^{them, it is preferable that R 13 to} R ¹⁶ are independently hydrogen atom, alkyl group, cycloalkyl group, or nitrogen atom-containing heterocyclic group.

As a specific example of difluorophosphate,
Examples thereof include lithium difluorophosphate, sodium difluorophosphate, potassium difluorophosphate and the like, and lithium difluorophosphate is preferable.
As the difluorophosphate, 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 difluorophosphate is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.001% by mass or more, preferably 0 in 100% by mass of the non-aqueous electrolyte solution. 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 2% by mass or less, most preferably. It is 1% by mass or less.
When the content of difluorophosphate is within this range, the non-aqueous electrolyte secondary battery tends to exhibit a sufficient effect of improving the cycle characteristics, the high temperature storage characteristics are lowered, and the amount of gas generated is increased. It is easy to avoid a situation where the discharge capacity retention rate decreases.

(Fluorosulfate)
The counter cation of the fluorosulfonate is not particularly limited, but lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, barium, and NR ¹⁷ R ¹⁸ R ¹⁹ R ²⁰ (in the formula, R ^{17 to R 20). 20} each independently represents a hydrogen atom or an organic group having 1 to 12 carbon atoms.) Ammonium and the like represented by) can be mentioned as an example.

The ^{organic group having 1 to 12 carbon atoms represented by R 17 to} R ²⁰ of the ammonium is not particularly limited, but is substituted with, for example, an alkyl group which may be substituted with a halogen atom, a halogen atom or an alkyl group. Examples thereof include a cycloalkyl group which may be present, an aryl group which may be substituted with a halogen atom or an alkyl group, a nitrogen atom-containing heterocyclic group which may have a substituent, and the like. Among ^{them, it is preferable that R 17 to} R ²⁰ are independently hydrogen atom, alkyl group, cycloalkyl group, or nitrogen atom-containing heterocyclic group.
Specific examples of fluorosulfonates include
Examples thereof include lithium fluorosulfonate, sodium fluorosulfonate, potassium fluorosulfonate, rubidium fluorosulfonate, cesium fluorosulfonate, and lithium fluorosulfonate is preferable.

As the fluorosulfonate, 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 fluorosulfonate is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.001% by mass or more, preferably 0 in 100% by mass of the non-aqueous electrolyte solution. 0.01% by mass or more, more preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 2% by mass or less, most preferably. It is 1% by mass or less.
When the content of the fluorosulfonate is within this range, the non-aqueous electrolyte secondary battery tends to exhibit a sufficient effect of improving the cycle characteristics, the high temperature storage characteristics are lowered, and the amount of gas generated is increased. It is easy to avoid a situation in which the discharge capacity retention rate decreases.

(Fluoroboron salt)
The counter cation of the fluoroboron salt is not particularly limited, but lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, barium, and NR ²¹ R ²² R ²³ R ²⁴ (in the formula, R ^{21 to} R ^24). Each independently represents a hydrogen atom or an organic group having 1 to 12 carbon atoms.) Ammonium and the like represented by) can be mentioned as an example.

The ^{organic group having 1 to 12 carbon atoms represented by R 21 to} R ²⁴ of the ammonium is not particularly limited, but is substituted with, for example, an alkyl group which may be substituted with a halogen atom, a halogen atom or an alkyl group. Examples thereof include a cycloalkyl group which may be present, an aryl group which may be substituted with a halogen atom or an alkyl group, a nitrogen atom-containing heterocyclic group which may have a substituent, and the like. Among ^{them, it is preferable that R 21 to} R ²⁴ are independently hydrogen atom, alkyl group, cycloalkyl group, or nitrogen atom-containing heterocyclic group.

Specific examples of fluoroboron salts include
_{LiBF 4, LiB (C i F} 2i + 1) j (F) 4-j , and the like, LiBF ₄ are preferred. In addition, i represents an integer of 1 to 10, and j represents an integer of 1 to 4.
As the fluoroboron salt, 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 fluoroboron salt is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired. However, in 100% by mass of the non-aqueous electrolyte solution, it is usually 0.001% by mass or more, preferably 0. 01% by mass or more, more preferably 0.1% by mass or more, and usually 3% by mass or less, preferably 1% by mass or less, more preferably 0.8% by mass or less, still more preferably 0.5% by mass or less. Most preferably, it is 0.3% by mass or less.
When the content of the fluoroboron salt is within this range, the non-aqueous electrolyte secondary battery tends to exhibit a sufficient effect of improving the cycle characteristics, the high temperature storage characteristics are lowered, the amount of gas generated is increased, and the discharge is performed. It is easy to avoid a situation where the capacity retention rate drops.

(Fluoroimide salt)
The counter cation of the fluoroimide salt is not particularly limited, but lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, barium, and NR ²⁵ R ²⁶ R ²⁷ R ²⁸ (in the formula, R ^{25 to} R ^28). Each independently represents a hydrogen atom or an organic group having 1 to 12 carbon atoms.) Ammonium and the like represented by) can be mentioned as an example.

The ^{organic group having 1 to 12 carbon atoms represented by R 25 to} R ²⁸ of the ammonium is not particularly limited, and is, for example, substituted with an alkyl group which may be substituted with a halogen atom, a halogen atom or an alkyl group. Examples thereof include a cycloalkyl group which may be substituted, an aryl group which may be substituted with a halogen atom or an alkyl group, a nitrogen atom-containing heterocyclic group which may have a substituent and the like. Among ^{them, it is preferable that R 25 to} R ²⁸ are independently hydrogen atom, alkyl group, cycloalkyl group, or nitrogen atom-containing heterocyclic group.

Specific examples of fluoroimide salts include
LiN (FCO) ₂ , LiN (FCO) (FSO ₂ ), LiN (FSO ₂ ) ₂ , LiN (FSO ₂ ) (CF ₃ SO ₂ ), LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO) ₂ ) ₂ , Lithium cyclic 1,2-perfluoroethanedisulfonylimide, Lithium cyclic 1,3-perfluoropropanedisulfonylimide, LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ ), LiN (FSO ₂ ) ₂ , LiN (CF ₃ SO ₂ ) ₂ , and LiN (C ₂ F ₅ SO ₂ ) ₂ are preferable.

As the fluoroimide salt, 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 fluoroimide salt is not particularly limited and is arbitrary 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, more preferably 0.1% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 2% by mass or less, most preferably 1. It is mass% or less.
When the content of the fluoroimide salt is within this range, the non-aqueous electrolyte secondary battery tends to exhibit a sufficient effect of improving the cycle characteristics, the high temperature storage characteristics are lowered, the amount of gas generated is increased, and the discharge is performed. It is easy to avoid a situation where the capacity retention rate drops.

<1-6. Auxiliary agent>
The non-aqueous electrolyte solution of the present embodiment may contain the following auxiliaries as long as the effects of the present invention are exhibited.
Unsaturated cyclic carbonates such as vinylene carbonate, vinylethylene carbonate or ethynylethylene carbonate;
Fluorinated cyclic carbonates such as monofluoroethylene carbonate, 4,5-difluoroethylene carbonate, 4,5-difluoroethylene carbonate and 4,5-difluoro-4,5-dimethylethylene carbonate;
Carbonate compounds such as methoxyethyl-methyl carbonate;
Spiro compounds such as methyl-2-propynyl oxalate;
Sulfur-containing compounds such as ethylene sulfite;
Isocyanate compounds such as diisocyanates having a cycloalkylene group such as 1,3-bis (isocyanatomethyl) cyclohexane;
Nitrogen-containing compounds such as 1-methyl-2-pyrrolidinone;
Hydrocarbon compounds such as cycloheptane;
Fluoro-containing aromatic compounds such as fluorobenzene;
Silane compounds such as tris borate (trimethylsilyl);
Ester compounds such as 2-propynyl 2- (methanesulfonyloxy) propionic acid;
Lithium salts such as lithium ethyl methyloxycarbonylphosphonate;
Isocyanic acid esters such as triallyl isocyanurate;
And so on. These may be used alone or in combination of two or more. By adding these auxiliaries, it is possible to suppress gas generation during initial conditioning and improve capacity retention characteristics and cycle characteristics after high-temperature storage.

Above all, in the non-aqueous electrolyte solution according to the embodiment of the present invention, gas generation during initial conditioning is further suppressed by using one or more selected from unsaturated cyclic carbonates and cyclic carbonates having a fluorine atom in combination. It is preferable in that a battery that does not easily swell can be obtained.
Hereinafter, the "unsaturated cyclic carbonate" and the "fluorinated cyclic carbonate" will be described in detail.

(Unsaturated cyclic carbonate)
As used herein, the "unsaturated cyclic carbonate" is a cyclic carbonate having a carbon-carbon unsaturated bond, and is a carbonate having a carbon-carbon unsaturated bond such as a carbon-carbon double bond or a carbon-carbon triple bond. If there is, any unsaturated cyclic carbonate can be used without particular limitation.
Examples of unsaturated cyclic carbonates include vinylene carbonates, ethylene carbonates substituted with a substituent having a carbon-carbon unsaturated bond, and the like.
Specific examples of vinylene carbonates include vinylene carbonate, methylvinylene carbonate, 4,5-dimethylvinylene carbonate and the like.
Specific examples of ethylene carbonates substituted with a substituent having a carbon-carbon unsaturated bond include vinyl ethylene carbonate, 4,5-divinylethylene carbonate, ethynylethylene carbonate, propargylethylene carbonate and the like.
Of these, vinylene carbonate, vinylethylene carbonate, and ethynylethylene carbonate are preferable, and vinylene carbonate in particular can contribute to the formation of a stable film-like structure and is more preferably used.
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, but is usually 50 or more, preferably 80 or more, and 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 combination in any combination and ratio. The content of the unsaturated cyclic carbonate is not particularly limited and is arbitrary as long as the effect of the present invention is not significantly impaired, but the content of the unsaturated cyclic carbonate is usually 0 in 100% by mass of the non-aqueous electrolyte solution. .001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.2% by mass or more, and usually 10% by mass or less. , It is 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.

(Fluorinated cyclic carbonate)
As used herein, the term "fluorinated cyclic carbonate" is a cyclic carbonate having a fluorine atom.
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, 4,5-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-dimethyl Ethylene carbonate, 4,4-difluoro-5,5-dimethylethylene carbonate and the like can be mentioned.
Among them, at least one selected from the group consisting of monofluoroethylene carbonate, 4,5-difluoroethylene carbonate, 4,5-difluoroethylene carbonate and 4,5-difluoro-4,5-dimethylethylene carbonate is highly ionic conductive. 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 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 the fluorinated cyclic carbonate when used as a non-aqueous solvent is usually 8% by mass or more, preferably 10% by mass or more, and more preferably 12% by mass or more in 100% by mass of the non-aqueous electrolyte solution. Yes, it is usually 85% by mass or less, preferably 80% by mass or less, and more preferably 75% by mass or less. Within this range, the non-aqueous electrolyte secondary battery tends to exhibit a sufficient effect of improving the cycle characteristics, and it is easy to avoid a decrease in the discharge capacity retention rate.
In the non-aqueous electrolyte solution according to the embodiment of the present invention, the unsaturated cyclic carbonate or the fluorinated cyclic carbonate is at least one selected from the group consisting of vinylene carbonate, vinylethylene carbonate, ethynylethylene carbonate, and fluoroethylene carbonate. It is preferably a seed.

As the fluorinated cyclic carbonate, a cyclic carbonate having an unsaturated bond and a fluorine atom (hereinafter, may be abbreviated as "fluorinated unsaturated cyclic carbonate") can be used. The fluorinated unsaturated cyclic carbonate is not particularly limited. Of these, those having one or two fluorine atoms are preferable. The method for producing the fluorinated unsaturated cyclic carbonate is not particularly limited, and a known method can be arbitrarily selected for production.
Examples of the fluorinated unsaturated cyclic carbonate include a vinylene carbonate derivative, an ethylene carbonate derivative substituted with an aromatic ring or a substituent having a carbon-carbon unsaturated bond, and the like.
Examples of the vinylene carbonate derivative include 4-fluorovinylene carbonate, 4-fluoro-5-methylvinylene carbonate, 4-fluoro-5-phenylvinylene carbonate, 4,5-difluoroethylene carbonate and the like.
Examples of the ethylene carbonate derivative substituted with an aromatic ring or a substituent having a carbon-carbon unsaturated bond include 4-fluoro-4-vinylethylene carbonate, 4-fluoro-5-vinylethylene carbonate, and 4,4-difluoro-4. -Vinylethylene carbonate, 4,5-difluoro-4-vinylethylene carbonate, 4-fluoro-4,5-divinylethylene carbonate, 4,5-difluoro-4,5-divinylethylene carbonate, 4-fluoro-4-phenyl Examples thereof include ethylene carbonate, 4-fluoro-5-phenylethylene carbonate, 4,4-difluoro-5-phenylethylene carbonate, 4,5-difluoro-4-phenylethylene carbonate and the like.
The molecular weight of the fluorinated unsaturated cyclic carbonate is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired, but is usually 50 or more, preferably 80 or more, and usually 250 or less, preferably 150 or less. Is. Within this range, it is easy to secure the solubility of the fluorinated cyclic carbonate in the non-aqueous electrolyte solution, and the effect of the present invention is likely to be exhibited.
As the fluorinated unsaturated cyclic carbonate, one type may be used alone, or two or more types may be used in combination in any combination and ratio. The amount of the fluorinated unsaturated 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 0.01% by mass or more, preferably 0.01% by mass or more in 100% by mass of the non-aqueous electrolyte solution. Is 0.1% by mass or more, more preferably 0.2% by mass or more, and usually 5% by mass or less, preferably 4% by mass or less, more preferably 3% by mass or less. Within this range, the non-aqueous electrolyte secondary battery tends to exhibit a sufficient effect of improving cycle characteristics.

Auxiliary agents other than unsaturated cyclic carbonates and fluorinated cyclic carbonates (contents of other auxiliary agents) are not particularly limited and are arbitrary as long as the effects of the present invention are not significantly impaired, but the total amount of the non-aqueous electrolyte solution can be used. On the other hand, it is usually 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and usually 5% by mass or less, preferably 3% by mass or less, more preferably. It is 1% by mass or less. Within this range, the effects of other auxiliaries are likely to be sufficiently exhibited, and high-temperature storage stability tends to be improved. When two or more kinds of other auxiliary agents are used in combination, the total amount of the other auxiliary agents may satisfy the above range.

<2. Non-aqueous electrolyte battery ＞
The non-aqueous electrolyte battery according to the embodiment of the present invention is a non-aqueous electrolyte battery including a positive electrode and a negative electrode and a non-aqueous electrolyte solution, and is a non-aqueous electrolyte battery according to the above-described embodiment of the present invention. And. More specifically, a positive electrode having a current collector and a positive electrode active material layer provided on the current collector and capable of occluding and releasing metal ions, and a current collector and a positive electrode provided on the current collector. The negative electrode having the negative electrode active material layer and capable of occluding and releasing metal ions, and the non-aqueous electrolyte solution are represented by the above general formula (A) or general formula (B) together with the alkali metal salt and the non-aqueous solvent. A non-aqueous electrolyte solution containing at least one compound having a Si—O structure and containing a compound having a Si—N structure represented by the above general formula (α) is provided.

<2-1. Battery configuration>
The non-aqueous electrolyte battery of the present embodiment has the same configuration as the conventionally known non-aqueous electrolyte battery except for the above-mentioned non-aqueous electrolyte battery. Usually, the positive electrode and the negative electrode are laminated via a porous film (separator) impregnated with the non-aqueous electrolyte solution, and these are housed in a case (exterior body). Therefore, the shape of the non-aqueous electrolyte battery of the present embodiment 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.

<2-2. Non-aqueous electrolyte solution>
As the non-aqueous electrolyte solution, the non-aqueous electrolyte solution according to the above-described embodiment of the present invention is used. It is also possible to mix and use another non-aqueous electrolyte solution with the above non-aqueous electrolyte solution as long as the gist of the present invention is not deviated.

<2-3. Positive electrode>
In one embodiment of the present invention, the positive electrode has a current collector and a positive electrode active material layer provided on the current collector.
The positive electrode used in the non-aqueous electrolyte battery of the present embodiment will be described in detail below.

<2-3-1. 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 a transition metal oxide containing lithium cobaltate or at least Ni and Co, and 50 mol% or more of the transition metal is Ni and Co, and is an electrochemically metal ion. There is no particular limitation as long as it can store and release lithium ions, but for example, those capable of storing and releasing lithium ions electrochemically are preferable, containing lithium, at least Ni and Co, and 60 mol of the transition metal. A transition metal oxide in which% or more is Ni and Co is preferable. This is because Ni and Co have a redox potential suitable for use as a positive electrode material for a secondary battery and are suitable for high-capacity applications.

The transition metal component of the lithium transition metal oxide includes Ni and Co as essential elements, but other metals include Mn, V, Ti, Cr, Fe, Cu, Al, Mg, Zr, Er and the like. Mn, Ti, Fe, Al, Mg, Zr and the like are preferable. Specific examples of the lithium transition metal oxide include LiCoO ₂ , LiNi _0.85 Co _0.10 Al _0.05 O ₂ , LiNi _0.80 Co _0.15 Al _0.05 O ₂ , and LiNi _0.33. Co _0.33 Mn _0.33 O ₂ , Li _1.05 Ni _0.33 Mn _0.33 Co _0.33 O ₂ , LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , Li _1.05 Ni _Examples thereof include 0.50 Mn _0.29 Co _0.21 O ₂ , LiNi _0.6 Co _0.2 Mn _0.2 O ₂ , LiNi _0.8 Co _0.1 Mn _0.1 O _2.

Above all, the aspect of the transition metal oxide represented by the following composition formula (1) is preferable.
Li _a1 Ni _b1 Co _c1 M _d1 O ₂ ... (1)
(In the above formula (1), a1, b1, c1 and d1 satisfy 0.90 ≦ a1 ≦ 1.10, 0 <b1 <0.4, b1 + c1 + d1 = 1. M is Mn, Al, Mg, Zr. , Fe, Ti and Er represents at least one element selected from the group.
In the composition formula (1), it is preferable to show a numerical value of 0.1 ≦ d1 <0.5.
Since the composition ratio of Ni and Co and the composition ratio of other metal species are as specified, it is difficult for the transition metal to elute from the positive electrode, and even if it elutes, Ni and Co can be contained in the non-aqueous secondary battery. This is because the adverse effect of

Above all, the aspect of the transition metal oxide represented by the following composition formula (2) is preferable.
Li _a2 Ni _b2 Co _c2 M _d2 O ₂ ... (2)
(In the above formula (2), a2, b2, c2 and d2 satisfy 0.90 ≦ a2 ≦ 1.10, 0.4 ≦ b2 <1.0, b2 + c2 + d2 = 1. M is Mn, Al, Mg. , Zr, Fe, Ti and Er represents at least one element selected from the group.
In the composition formula (2), it is preferable to show a value of 0.10 ≦ d2 <0.40. Further, it is preferable to show a numerical value of 0.50 ≦ b2 ≦ 0.96.
Since Ni and Co are the main components and the composition ratio of Ni is larger than the composition ratio of Co, it is possible to take out a stable and high capacity when used as a positive electrode of a non-aqueous electrolyte battery. Because it becomes.

Above all, the aspect of the transition metal oxide represented by the following composition formula (3) is preferable.
Li _a3 Ni _b3 Co _c3 M _d3 O ₂ ... (3)
(In the formula (3), the numerical values of 0.90 ≦ a3 ≦ 1.10, 0.50 ≦ b3 ≦ 0.94, 0.05 ≦ c3 ≦ 0.2, and 0.01 ≦ d3 ≦ 0.3 are shown. , B3 + c3 + d3 = 1. M represents at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti and Er.)
In the composition formula (3), it is preferable to show a numerical value of 0.10 ≦ d3 ≦ 0.3.
This is because the above composition makes it possible to take out a particularly high capacity when used as a positive electrode of a non-aqueous secondary battery.

Further, two or more of the above-mentioned positive electrode active materials may be mixed and used. Similarly, at least one or more of the above positive electrode active materials may be mixed and used with other positive electrode active materials. Examples of other positive electrode active materials include transition metal oxides, transition metal phosphoric acid compounds, transition metal silicic acid compounds, and transition metal boric acid compounds not listed above.
Of these, a lithium manganese composite oxide having a spinel-type structure and a lithium-containing transition metal phosphoric acid compound having an olivine-type structure are preferable. Specific examples of the lithium manganese composite oxide having a spinel-type structure include LiMn ₂ O ₄ , LiMn _1.8 Al _0.2 O ₄ , LiMn _1.5 Ni _0.5 O _{4, and the} like. This is because the structure is the most stable, oxygen is less likely to be released even when the non-aqueous electrolyte battery is abnormal, and the safety is excellent.
The transition metal of the lithium-containing transition metal phosphoric acid compound is preferably V, Ti, Cr, Mn, Fe, Co, Ni, Cu or the like, and specific examples thereof include LiFePO ₄ and Li ₃ Fe ₂ (PO _4). ) ₃ , Iron phosphates such as _{LiFeP 2} O ₇ , cobalt phosphates such as _{LiCoPO 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 and Ti. , V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, W and the like.
Of these, a lithium iron phosphoric acid compound is preferable. This is because iron is an extremely inexpensive metal with abundant resources and is less harmful. That is, among the above specific examples, LiFePO ₄ can be mentioned as a more preferable specific example.

In one embodiment of the present invention, the positive electrode is an NMC positive electrode, and the NMC positive electrode preferably has a nickel element content of 30 mol% or more, and a non-aqueous electrolyte battery having a nickel element content of 40 mol% or more. It is more preferable from the viewpoint of increasing the capacity.
Here, in the present specification, the NMC positive electrode means a positive electrode in which the positive electrode active material contains nickel, manganese, and cobalt (NMC) and is a material represented by the following formula (I).
Li _a Ni _b Co _c Mn _d O ₂ ... (I)
(In the above formula (I), a, b, c and d satisfy 0.90 ≦ a ≦ 1.10 and b + c + d = 1.)

(2) Surface Coating A substance having a composition different from that of the substance constituting the main positive electrode active material (hereinafter, appropriately referred to as “surface adhering substance”) may be used on the surface of the above-mentioned positive electrode active material. .. Examples of surface adhering substances include aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, magnesium oxide, calcium oxide, boron oxide, antimony oxide, bismuth oxide and other oxides, lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, etc. Examples thereof include sulfates such as calcium sulfate and aluminum sulfate, carbonates such as lithium carbonate, calcium carbonate and magnesium carbonate, and carbon.

These surface-adhering substances are, for example, dissolved or suspended in a solvent, impregnated and added to the positive electrode active material, and then dried, or the surface-adhering substance precursor is dissolved or suspended in the solvent and impregnated and added to the positive electrode active material. After that, it can be adhered to the surface of the positive electrode active material by a method of reacting by heating or the like, a method of adding to the positive electrode active material precursor and firing at the same time, or the like. When carbon is attached, a method of mechanically attaching the carbon substance later in the form of activated carbon or the like can also be used.

The mass of the surface-adhering substance adhering to the surface of the positive electrode active material is preferably 0.1 ppm or more, more preferably 1 ppm or more, still more preferably 10 ppm or more, based on the mass of the positive electrode active material. Further, it is preferably 20% or less, more preferably 10% or less, still more preferably 5% or less.
The surface-adhering substance can suppress the oxidation reaction of the non-aqueous electrolyte solution on the surface of the positive electrode active material, and can improve the battery life. Further, when the amount of adhesion is within the above range, the effect can be sufficiently exhibited, and the resistance is less likely to increase without hindering the inflow and outflow of lithium ions.

(3) Shape As the shape of the positive electrode active material particles, a lump, a polyhedral shape, a spherical shape, an elliptical spherical shape, a plate shape, a needle shape, a columnar shape, or the like, which are conventionally used, are used. Further, the primary particles may be aggregated to form secondary particles, and the shape of the secondary particles may be spherical or elliptical spherical.

(4) 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, but some methods are mentioned and are general as a method for producing an inorganic compound. The method is used.
In particular, various methods can be considered for producing spherical or elliptical spherical active materials. For example, one example thereof is a transition metal raw material such as transition metal nitrate or sulfate, and if necessary, a raw material of another element. 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 NO. Examples thereof include a method of adding a Li source such as _{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. Then, it is dried and molded with a spray dryer or the like to form a spherical or elliptical spherical precursor, to which _{Li sources such as LiOH, Li 2} CO ₃ and _{Li NO 3} are added and fired at a high temperature to obtain an active material. Can be mentioned.

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 , or 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.

<2-3-2. Positive electrode structure and manufacturing method>
Hereinafter, the configuration of the positive electrode used in the present invention and the method for producing the same will be described.
(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 the positive electrode current collector, or these materials are applied to a liquid medium. A positive electrode can be obtained by forming a positive electrode active material layer on the current collector by applying it to a positive electrode current collector and drying it as a slurry.

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 characteristics 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. Cobalt or nickel is an expensive metal with a small amount of resources, and it is cheaper because it is not preferable in terms of cost because the amount of active material used is large in large batteries that require high capacity such as for automobile applications. This is because it is desirable to use manganese as a main component as a transition metal.

<2-4. Negative electrode ＞
The negative electrode active material used for the negative electrode will be described below. The negative electrode active material is not particularly limited as long as it can electrochemically occlude and release metal ions. Specific examples include those having carbon as a constituent element of carbonaceous materials, alloy-based materials, and the like. One of these may be used alone, or two or more thereof may be arbitrarily combined and used in combination.

<2-4-1. Negative electrode active material>
Examples of the negative electrode active material include carbonaceous materials and alloy-based materials as described above.

Examples of the carbonaceous material include (1) natural graphite, (2) artificial graphite, (3) amorphous carbon, (4) carbon-coated graphite, (5) graphite-coated graphite, and (6) resin-coated graphite. Be done.

(1) Examples of natural graphite include scaly graphite, scaly graphite, soil graphite and / or graphite particles obtained by subjecting these graphites to a treatment such as spheroidization or densification. Among these, spherical or ellipsoidal graphite that has been subjected to a spheroidizing treatment is particularly preferable from the viewpoint of particle packing property and charge / discharge rate characteristics.

As the device used for the spheroidizing process, for example, a device that repeatedly applies mechanical actions such as compression, friction, and shear force, including impact force and particle interaction, to the particles can be used.

Specifically, it has a rotor with a large number of blades installed inside the casing, and by rotating the rotor at high speed, impact compression, friction, and shearing force are applied to the raw material of natural graphite (1) introduced inside. A device that gives a mechanical action such as, etc. to perform the spheroidizing process is preferable. Further, an apparatus having a mechanism for repeatedly giving a mechanical action by circulating a raw material is preferable.

For example, in the case of sphericalizing using the above-mentioned device, the peripheral speed of the rotating rotor is preferably set to 30 to 100 m / sec, more preferably 40 to 100 m / sec, and 50 to 100 m / sec. It is even more preferable to set it to seconds. Further, the spheroidizing treatment can be performed by simply passing the raw material through the device, but it is preferable to circulate or retain the inside of the device for 30 seconds or more, and to circulate or stay in the device for 1 minute or more. Is more preferable.

(2) As artificial graphite, coal tar pitch, coal-based heavy oil, atmospheric residual oil, petroleum-based heavy oil, aromatic hydrocarbons, nitrogen-containing cyclic compounds, sulfur-containing cyclic compounds, polyphenylene, polyvinyl chloride, etc. Organic compounds such as polyvinyl alcohol, polyacrylonitrile, polyvinyl butyral, natural polymers, polyphenylene silfide, polyphenylene oxide, furfuryl alcohol resin, phenol-formaldehyde resin, and imide resin are usually used in the range of 2500 ° C or higher and usually 3200 ° C or lower. Examples thereof include those produced by graphitization at temperature, crushing and / or classifying as necessary.

At this time, a silicon-containing compound, a boron-containing compound, or the like can also be used as a graphitization catalyst. In addition, artificial graphite obtained by graphitizing mesocarbon microbeads separated in a pitch heat treatment process can be mentioned. Further, artificial graphite of granulated particles composed of primary particles can also be mentioned. For example, mesocarbon microbeads, graphitizable carbon material powder such as coke, graphitizable binder such as tar and pitch, and graphitization catalyst are mixed, graphitized, and pulverized if necessary. Examples thereof include graphite particles obtained by assembling or bonding a plurality of flat particles so that the orientation planes are non-parallel.

(3) As the amorphous carbon, an amorphous carbon which uses an easily graphitizable carbon precursor such as tar or pitch as a raw material and is heat-treated at least once in a temperature range (range of 400 to 2200 ° C.) where graphitization does not occur. Examples thereof include amorphous carbon particles that have been heat-treated using particles or a non-graphitizable carbon precursor such as a resin as a raw material.

(4) Examples of the carbon-coated graphite include those obtained as follows. Natural graphite and / or artificial graphite is mixed with a carbon precursor which is an organic compound such as tar, pitch or resin, and heat-treated at least once in the range of 400 to 2300 ° C. The obtained natural graphite and / or artificial graphite is used as nuclear graphite, and this is coated with amorphous carbon to obtain a carbon graphite composite. This carbon-graphite composite is mentioned as carbon-coated graphite (4).

Further, the composite form is a form in which a plurality of primary particles are composited using carbon derived from the carbon precursor as a binder even when the entire surface or a part of the surface of nuclear graphite is coated with amorphous carbon. You may. It is also possible to react natural graphite and / or artificial graphite with hydrocarbon gases such as benzene, toluene, methane, propane, and aromatic volatiles at high temperatures to deposit carbon on the graphite surface (CVD). The carbon graphite composite can be obtained.

(5) As the graphite-coated graphite, those obtained as follows can be mentioned. Natural graphite and / or artificial graphite is mixed with a carbon precursor of an easily graphitizable organic compound such as tar, pitch or resin, and heat-treated at least once in the range of about 2400 to 3200 ° C. The obtained natural graphite and / or artificial graphite is used as nuclear graphite, and the whole or part of the surface of the nuclear graphite is coated with graphite to obtain graphite-coated graphite (5).

(6) As the resin-coated graphite, for example, natural graphite and / or artificial graphite obtained by mixing natural graphite and / or artificial graphite with a resin or the like and drying at a temperature of less than 400 ° C. is used as nuclear graphite, and the resin or the like is used. It is obtained by coating the nuclear graphite with.

Further, as the carbonaceous materials of (1) to (6) described above, one kind may be used alone, or two or more kinds may be used in any combination and ratio.

Examples of the organic compounds such as tar, pitch and resin used for the carbonaceous materials (2) to (5) above include coal-based heavy oil, DC-based heavy oil, decomposition-based petroleum heavy oil, and aromatic hydrocarbons. , N-ring compounds, S-ring compounds, polyphenylenes, synthetic organic polymers, natural polymers, thermoplastic resins, thermosetting resins and the like, which are carbonizable organic compounds selected from the group. Further, the raw material organic compound may be used by being dissolved in a small molecule organic solvent in order to adjust the viscosity at the time of mixing.

Further, as the natural graphite and / or the artificial graphite which is a raw material of the nuclear graphite, the natural graphite which has been subjected to the spheroidizing treatment is preferable.

Next, the alloy-based material used as the negative electrode active material is lithium alone, a single metal and alloy forming a lithium alloy, or their oxides, carbides, nitrides, silides, if lithium can be occluded and released. It may be any compound such as a compound, a sulfide or a phosphor, and is not particularly limited. The elemental metals and alloys forming the lithium alloy are preferably materials containing group 13 and group 14 metal / semi-metal elements (that is, excluding carbon), more preferably elemental metals of aluminum, silicon and tin, and these. It is an alloy or compound containing an atom, and more preferably, it has silicon or tin as a constituent element, such as a simple substance metal of silicon and tin and an alloy or compound containing these atoms.
One of these may be used alone, or two or more thereof may be used in any combination and ratio.

<Metal particles that can be alloyed with Li>
When a single metal and alloy forming a lithium alloy, or a compound such as an oxide, carbide, nitride, silicide, sulfide or phosphate thereof is used as a negative electrode active material, the metal that can be alloyed with Li is It is in particle form. Methods for confirming that the metal particles are metal particles that can be alloyed with Li include identification of the metal particle phase by X-ray diffraction, observation and element analysis of the particle structure by an electron microscope, and elements by fluorescent X-ray. Analysis etc. can be mentioned.

As the metal particles that can be alloyed with Li, any conventionally known metal particles can be used.
From the viewpoint of the capacity and cycle life of the non-aqueous electrolyte battery, the metal particles are, for example, Fe, Co, Sb, Bi, Pb, Ni, Ag, Si, Sn, Al, Zr, Cr, P, S, V. , Mn, As, Nb, Mo, Cu, Zn, Ge, In, Ti and W, preferably a metal or a compound thereof selected from the group. Further, an alloy composed of two or more kinds of metals may be used, and the metal particles may be alloy particles formed by two or more kinds of metal elements. Among these, a metal selected from the group consisting of Si, Sn, As, Sb, Al, Zn and W or a metal compound thereof is preferable.

Examples of the metal compound include metal oxides, metal nitrides, metal carbides and the like. Further, an alloy composed of two or more kinds of metals may be used.

Among the metal particles that can be alloyed with Li, Si or a Si metal compound is preferable. The Si metal compound is preferably a Si metal oxide. Si or a Si metal compound is preferable in terms of increasing the capacity of the battery. In this specification, Si or Si metal compounds are collectively referred to as Si compounds. The Si compound, _{specifically, SiO x, SiN x, SiC} x, SiZ x O y (Z = C, N) , and the like. The Si compound is preferably a Si metal oxide, and the Si metal oxide is SiO _x in the general formula. This general formula SiO _x is obtained by using silicon dioxide (SiO ₂ ) and metal Si (Si) as raw materials, and the value of x is usually 0 ≦ x <2. SiO _x has a larger theoretical capacity than graphite, and amorphous Si or nano-sized Si crystals can easily move in and out of alkaline ions such as lithium ions, so that a high capacity can be obtained.

The Si metal oxide is specifically _{represented as SiO x} , where x is 0 ≦ x <2, more preferably 0.2 or more and 1.8 or less, still more preferably 0. It is 4 or more and 1.6 or less, particularly preferably 0.6 or more and 1.4 or less. Within this range, the battery has a high capacity, and at the same time, the irreversible capacity due to the combination of Li and oxygen can be reduced.

<Oxygen content of metal particles that can be alloyed with Li>
The oxygen content of the metal particles that can be alloyed with Li is not particularly limited, but is usually 0.01% by mass or more and 8% by mass or less, and preferably 0.05% by mass or more and 5% by mass or less. The oxygen distribution state in the particle may be present near the surface, inside the particle, or uniformly present in the particle, but it is particularly preferable that the oxygen is present near the surface. When the amount of oxygen contained in the metal particles that can be alloyed with Li is within the above range, the strong bond between the metal particles and O (oxygen atom) suppresses the volume expansion due to the secondary charge / discharge of the non-aqueous electrolyte solution. It is preferable because it has excellent cycle characteristics.

<Negative electrode active material containing metal particles and graphite particles that can be alloyed with Li>
The negative electrode active material may contain metal particles that can be alloyed with Li and graphite particles. The negative electrode active material may be a mixture in which Li and alloyable metal particles and graphite particles are mixed in the state of mutually independent particles, or Li and alloyable metal particles are mixed on the surface of the graphite particles and on the surface of the graphite particles. / Or it may be a complex existing inside.

The composite of the metal particles that can be alloyed with Li and the graphite particles (also referred to as composite particles) is particularly limited as long as the particles contain the metal particles that can be alloyed with Li and the graphite particles. However, it is preferably particles in which metal particles and graphite particles that can be alloyed with Li are integrated by physical and / or chemical bonding. In a more preferable form, the metal particles and graphite particles that can be alloyed with Li are present in the particles in a dispersed manner so that the metal particles and graphite particles are present at least on the surface of the composite particles and inside the bulk. It is in the form in which graphite particles are present to unite them by physical and / or chemical bonding. A more specific preferred form is a composite material composed of at least Li and alloyable metal particles and graphite particles, in which the graphite particles, preferably natural graphite, have a curved structure and have a folded structure. In addition, it is a composite material (negative electrode active material) characterized in that metal particles that can be alloyed with Li are present in the gaps in the structure. Further, the gap may be a void, and a substance such as amorphous carbon, a graphitic substance, or a resin that buffers the expansion and contraction of metal particles that can be alloyed with Li exists in the gap. You may.

<Content ratio of metal particles that can be alloyed with Li>
The content ratio of the metal particles that can be alloyed with Li to the total of the metal particles that can be alloyed with Li and the metal particles that can be alloyed with Li is usually 0.1% by mass or more, preferably 0.5% by mass or more, and more preferably 1. It is 0% by mass or more, more preferably 2.0% by mass or more. Further, it is usually 99% by mass or less, preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, still more preferably 25% by mass or less, still more preferably 20% by mass or less, particularly. It is preferably 15% by mass or less, and most preferably 10% by mass or less. Within this range, side reactions on the Si surface can be controlled, and a sufficient capacity can be obtained in a non-aqueous electrolyte battery, which is preferable.

<Coverage>
In the present embodiment, the negative electrode active material may be coated with a carbonaceous material or a graphitic material. Of these, coating with an amorphous carbonaceous material is preferable from the viewpoint of lithium ion acceptability. This coverage is usually 0.5% or more and 30% or less, preferably 1% or more and 25% or less, and more preferably 2% or more and 20% or less. The upper limit of the coverage is from the viewpoint of reversible capacity when the battery is assembled, and the lower limit of the coverage is from the viewpoint that the core carbonaceous material is uniformly coated with amorphous carbon to achieve strong granulation. From the viewpoint of the particle size of the particles obtained when pulverized after firing, the above range is preferable.

The finally obtained coverage (content) of carbides derived from the organic compound of the negative electrode active material is the amount of the negative electrode active material, the amount of the organic compound, and the balance measured by the micro method based on JIS K 2270. It can be calculated by the following formula from the coal ratio.

Formula: Coverage of carbides derived from organic compounds (%) = (mass of organic compounds x residual coal ratio x 100) / {mass of negative electrode active material + (mass of organic compounds x residual carbon ratio)}

<Internal porosity>
The internal porosity of the negative electrode active material is usually 1% or more, preferably 3% or more, more preferably 5% or more, still more preferably 7% or more. Further, it is usually less than 50%, preferably 40% or less, more preferably 30% or less, still more preferably 20% or less. If this internal porosity is too small, the amount of liquid in the particles of the negative electrode active material tends to decrease in the non-aqueous electrolyte battery. On the other hand, if the internal porosity is too large, the interparticle gap tends to decrease when the electrode is used. The lower limit of the internal porosity is preferably in the above range from the viewpoint of charge / discharge characteristics, and the upper limit is preferably in the above range from the viewpoint of diffusion of the non-aqueous electrolyte solution. Further, as described above, the gap may be a void, and a substance such as amorphous carbon, a graphitic material, or a resin that buffers the expansion and contraction of metal particles that can be alloyed with Li is a gap. The presence or gap in it may be filled with these.

<2-4-2. Negative electrode configuration and manufacturing method>
Any known method can be used for producing the negative electrode as long as the effects of the present invention are not significantly impaired. For example, it is formed by adding a binder, a solvent, and if necessary, a thickener, a conductive material, a filler, etc. to a negative electrode active material to form a slurry, which is applied to a current collector, dried, and then pressed. can do.

Further, the alloy-based material negative electrode can be produced by any known method.
Specifically, as a method for manufacturing a negative electrode, for example, a method in which a binder, a conductive material, or the like is added to the above-mentioned negative electrode active material is directly rolled to form a sheet electrode, or compression molding is performed to form a pellet electrode. However, usually, the above-mentioned negative electrode is used by a coating method, a vapor deposition method, a sputtering method, a plating method, or the like on a current collector for a negative electrode (hereinafter, may be referred to as a “negative electrode current collector”). A method of forming a thin film layer (negative electrode active material layer) containing an active material is used. In this case, a binder, a thickener, a conductive material, a solvent, etc. are added to the above-mentioned negative electrode active material to form a slurry, which is applied to the negative electrode current collector, dried, and then pressed to increase the density. , A negative electrode active material layer is formed on the negative electrode current collector.

Examples of the material of the negative electrode current collector include steel, copper, copper alloy, nickel, nickel alloy, stainless steel and the like. Of these, copper foil is preferable from the viewpoint of easy processing into a thin film and cost.

The thickness of the negative electrode current collector is usually 1 μm or more, preferably 5 μm or more, and usually 100 μm or less, preferably 50 μm or less. If the thickness of the negative electrode current collector is too thick, the capacity of the entire non-aqueous electrolyte battery may be reduced too much, and conversely, if it is too thin, handling may be difficult.

In addition, in order to improve the binding effect with the negative electrode active material layer formed on the surface, it is preferable that the surface of these negative electrode current collectors is roughened in advance. Surface roughening methods include blasting, rolling with a rough surface roll, polishing cloth with abrasive particles fixed, and a machine that polishes the surface of the current collector with a wire brush equipped with a grindstone, emeri buff, steel wire, etc. Specific polishing method, electrolytic polishing method, chemical polishing method and the like can be mentioned.

Further, in order to reduce the mass of the negative electrode current collector and improve the energy density per mass of the battery, a perforated type negative electrode current collector such as expanded metal or punching metal can also be used. The mass of this type of negative electrode current collector can be freely changed by changing the aperture ratio. Further, when the negative electrode active material layers are formed on both sides of this type of negative electrode current collector, the negative electrode active material layer is less likely to be peeled off due to the rivet effect through the holes. However, when the aperture ratio becomes too high, the contact area between the negative electrode active material layer and the negative electrode current collector becomes small, so that the adhesive strength may be rather low.

The slurry for forming the negative electrode active material layer is usually prepared by adding a binder, a thickener, or the like to the negative electrode material. The term "negative electrode material" as used herein refers to a material that is a combination of the negative electrode active material and the conductive material.

The content of the negative electrode active material in the negative electrode material is usually 70% by mass or more, particularly preferably 75% by mass or more, and usually 97% by mass or less, particularly preferably 95% by mass or less. If the content of the negative electrode active material is too small, the capacity of the secondary battery using the obtained negative electrode tends to be insufficient, and if it is too large, the content of the conductive material is relatively insufficient, so that electricity as the negative electrode is used. It tends to be difficult to secure conductivity. When two or more negative electrode active materials are used in combination, the total amount of the negative electrode active materials may satisfy the above range.

Examples of the conductive material used for the negative electrode include metal materials such as copper and nickel; carbon materials such as graphite and carbon black. One of these may be used alone, or two or more thereof may be used in any combination and ratio. In particular, it is preferable to use a carbon material as the conductive material because the carbon material also acts as an active material. The content of the conductive material in the negative electrode material is usually 3% by mass or more, preferably 5% by mass or more, and usually 30% by mass or less, preferably 25% by mass or less. If the content of the conductive material is too small, the conductivity tends to be insufficient, and if it is too large, the content of the negative electrode active material or the like is relatively insufficient, so that the battery capacity and strength tend to decrease. When two or more conductive materials are used in combination, the total amount of the conductive materials may satisfy the above range.

As the binder used for the negative electrode, any binder can be used as long as it is a material that is safe for the solvent and electrolytic solution used in the production of the electrode. Examples thereof include polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, styrene / butadiene rubber / isoprene rubber, butadiene rubber, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer and the like. One of these may be used alone, or two or more thereof may be used in any combination and ratio. The content of the binder is usually 0.5 parts by mass or more, preferably 1 part by mass or more, usually 10 parts by mass or less, and preferably 8 parts by mass or less with respect to 100 parts by mass of the negative electrode material. .. If the content of the binder is too small, the strength of the obtained negative electrode tends to be insufficient, and if it is too large, the content of the negative electrode active material or the like is relatively insufficient, so that the battery capacity and conductivity tend to be insufficient. It becomes. When two or more binders are used in combination, the total amount of the binders may satisfy the above range.

Examples of the thickener used for the negative electrode include carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein and the like. One of these may be used alone, or two or more thereof may be used in any combination and ratio. The thickener may be used as needed, but when used, the content of the thickener in the negative electrode active material layer is usually in the range of 0.5% by mass or more and 5% by mass or less. Is preferable.

The slurry for forming the negative electrode active material layer is prepared by mixing the negative electrode active material with a conductive material, a binder, and a thickener as necessary, and using an aqueous solvent or an organic solvent as a dispersion medium. NS. Water is usually used as the aqueous solvent, but alcohols such as ethanol and organic solvents such as cyclic amides such as N-methylpyrrolidone are used in combination with water in a range of 30% by mass or less. You can also. Examples of the organic solvent include cyclic amides such as N-methylpyrrolidone, linear amides such as N, N-dimethylformamide and N, N-dimethylacetamide, and aromatic hydrocarbons such as anisole, toluene and xylene. , Butanol, cyclohexanol and the like, and among them, cyclic amides such as N-methylpyrrolidone and linear amides such as N, N-dimethylformamide and N, N-dimethylacetamide are preferable. It should be noted that any one of these may be used alone, or two or more thereof may be used in any combination and ratio.

The obtained slurry is applied onto the above-mentioned negative electrode current collector, dried, and then pressed to form a negative electrode active material layer, and a negative electrode is obtained. The method of application is not particularly limited, and a method known per se can be used. The drying method is not particularly limited, and known methods such as natural drying, heat drying, and vacuum drying can be used.

<Electrode density>
The electrode structure when the negative electrode active material is converted into an electrode is not particularly limited, but the density of the negative electrode active material existing on the current collector ^{is preferably 1 g · cm -3} or more, and 1.2 g · cm ^-3 or more. Is more preferable, 1.3 g · cm ^-3 or more is particularly preferable, 2.2 g · cm ^-3 or less is preferable, 2.1 g · cm ^-3 or less is more preferable, and 2.0 g · cm ^-3 or less is more preferable. More preferably, 1.9 g · cm ^-3 or less is particularly preferable. If the density of the negative electrode active material existing on the current collector exceeds the above range, the negative electrode active material particles will be destroyed, the initial irreversible capacity of the non-aqueous electrolyte battery will increase, and the current collector / negative electrode active material will increase. High current density charge / discharge characteristics may deteriorate due to a decrease in the permeability of the non-aqueous electrolyte solution near the interface. On the other hand, if it falls below the above range, the conductivity between the negative electrode active materials may decrease, the battery resistance may increase, and the capacity per unit volume may decrease.

<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 of the conductive material 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 in the production of the positive electrode active material layer is not particularly limited as long as it is a material stable to the non-aqueous electrolyte solution and the solvent used in the production of the electrode.
In the case of the coating method, the material is not particularly limited as long as it is a material that is dissolved or dispersed in the liquid medium used at the time of electrode production, but specific examples thereof include polyethylene, polypropylene, polyethylene terephthalate, polymethyl methacrylate, aromatic polyamide, and cellulose. , Resin-based polymer such as nitrocellulose; rubber-like polymer such as SBR (styrene / butadiene rubber), NBR (acrylonitrile / butadiene rubber), fluorine rubber, isoprene rubber, butadiene rubber, ethylene / propylene rubber; styrene / butadiene / Styrene block copolymer or its hydrogen additive, EPDM (ethylene / propylene / diene ternary copolymer), styrene / ethylene / butadiene / ethylene copolymer, styrene / isoprene / styrene block copolymer or its hydrogen additive Thermoplastic elastomeric polymers such as syndiotactic-1,2-polybutadiene, polyvinylacetate, ethylene / vinylacetate copolymer, propylene / α-olefin copolymer and other soft resinous polymers; polyvinylidene fluoride (PVdF), polyvinylidene fluoride, polyvinylidene fluoride, tetrafluoroethylene / ethylene copolymer, and other fluoropolymers; polymer compositions having ionic conductivity of alkali metal ions (particularly lithium ions), etc. Can be mentioned. 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, more preferably 1% by mass or more, further preferably 3% by mass or more, and preferably 80% by mass or less. Yes, 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 and the mechanical strength of the positive electrode can be ensured, so that the battery performance such as cycle characteristics is improved. Further, it also leads to avoiding a decrease in battery capacity and conductivity.

<Liquid medium>
As the liquid medium used for preparing the slurry for forming the positive electrode active material layer, the positive electrode active material, the conductive material, the binder, and the thickener used as needed can be dissolved or dispersed. The type of solvent 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. Examples of organic media include aliphatic hydrocarbons such as hexane; aromatic hydrocarbons such as benzene, toluene, xylene and methylnaphthalene; heterocyclic compounds such as quinoline and pyridine; ketones such as acetone, methylethylketone and cyclohexanone. Classes; esters such as methyl acetate and methyl acrylate; amines such as diethylenetriamine, N, N-dimethylaminopropylamine; ethers such as diethyl ether and tetrahydrofuran (THF); N-methylpyrrolidone (NMP), dimethylformamide. , Amides such as dimethylacetamide; aprotonic polar solvents such as hexamethylphosphalamide and dimethylsulfoxide can be mentioned. 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.

<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 positive electrode active material is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and further preferably 0.6% by mass or more. It is preferable, preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 2% by mass or less. When the ratio of the thickener to the positive electrode active material is within the above range, the coating property of the slurry is good, and the ratio of the active material to the positive electrode active material layer is sufficient, so that the capacity of the battery is reduced. It becomes easy to avoid the problem of increasing the resistance between the positive electrode active materials and the problem of increasing the resistance.

<Consolidation>
The positive electrode active material layer obtained by applying and drying the slurry to the current collector 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. 3.5 g · cm ^-3 or less is more preferable, and 3 g · cm ^-3 or less is particularly preferable.
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 the charge / discharge characteristics are particularly good at high current densities. Become. 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 the 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. 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 electrodes of the positive electrode with respect to the surface area of the exterior of the non-aqueous electrolyte 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 above non-aqueous electrolyte solution is used, the electric capacity (electrical capacity when the battery is discharged from a fully charged state to a discharged state) of the battery element housed in one battery exterior of the non-aqueous electrolyte battery is determined. When it is 1 amper hour (Ah) or more, the effect of improving the low temperature discharge characteristics becomes large, which is preferable. Therefore, the positive electrode plate has a fully charged discharge capacity, preferably 3 Ah (ampere hour) or more, more preferably 4 Ah or more, preferably 100 Ah or less, more preferably 70 Ah or less, and particularly preferably. Design to be 50 Ah or less.

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 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 the thickness of the positive electrode active material layer with respect to one side of the current collector. 10 μm or more is preferable, 20 μm or more is more preferable, 200 μm or less is preferable, and 100 μm or less is more preferable.

<2-5. Separator>
A separator is usually interposed between the positive electrode and the negative electrode to prevent a short circuit. In this case, the non-aqueous electrolyte solution according to the embodiment of the present invention is usually used by impregnating the 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 electrolyte solution according to the embodiment of the present invention are used, and are in the form of a porous sheet or a non-woven fabric having excellent liquid retention. It is preferable to use a thing or the like.

As the material of the resin and the glass fiber separator, for example, polyolefins such as polyethylene and polypropylene, 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 usually 1 μm or more, preferably 5 μm or more, more preferably 10 μm or more, and usually 50 μm or less, preferably 40 μm or less, more preferably 30 μm or less. If the separator is too thin than the above range, the insulating property and mechanical strength may decrease. Further, if it is too thick than the above range, not only the battery performance such as rate characteristics may be deteriorated, but also the energy density of the non-aqueous electrolyte battery as a whole may be lowered.

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 usually 20% or more, preferably 35% or more, more preferably 45% or more. Further, it is usually 90% or less, preferably 85% or less, and more preferably 75% or less. If the porosity is too small than the above range, the film resistance tends to increase and the rate characteristics tend to deteriorate. On the other hand, if it is larger than the above range, the mechanical strength of the separator tends to decrease, and the insulating property tends to decrease.

The average pore size of the separator is also arbitrary, but is usually 0.5 μm or less, preferably 0.2 μm or less, and usually 0.05 μm or more. If the average pore diameter exceeds the above range, a short circuit is likely to occur. Further, if it falls below the above range, the film resistance may increase and the rate characteristics may deteriorate.

On the other hand, as the inorganic material, for example, oxides such as alumina and silicon dioxide, nitrides such as aluminum nitride and silicon nitride, and sulfates such as barium sulfate and calcium sulfate are used, and have a particle shape or a fiber shape. Things are used.

As the form, a thin film such as a non-woven fabric, a woven fabric, or a microporous film is used. As the thin film shape, a thin film having a pore diameter of 0.01 to 1 μm and a thickness of 5 to 50 μm is 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 may be formed on both sides of the positive electrode by using a fluororesin as a binder to form a porous layer.

<2-6. Battery design>
[Electrode group]
The electrode group has a laminated structure in which the above-mentioned positive electrode plate and the negative electrode plate are formed by the above-mentioned separator, and a structure in which the above-mentioned positive electrode plate and the negative electrode plate are spirally wound through the above-mentioned separator. Either may be used. 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 usually 40% or more, preferably 50% or more, and usually 90% or less, 80% or less. preferable. The lower limit of the electrode group occupancy rate is preferably in the above range from the viewpoint of battery capacity. In addition, the upper limit of the electrode group occupancy rate is to secure a gap space from the viewpoint of various characteristics such as charge / discharge repetition performance as a battery and high temperature storage, and from the viewpoint of avoiding the operation of the gas discharge valve that releases the internal pressure to the outside. It is preferably in the above range. If the gap space is too small, the temperature of the battery will increase, causing the members to expand and the vapor pressure of the liquid component of the electrolyte to increase, resulting in an increase in internal pressure. In some cases, the gas release valve that reduces various characteristics and releases the internal pressure to the outside is activated.

[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, it is preferable to use a structure that reduces the resistance of the wiring portion and the joint portion. .. When the internal resistance is reduced in this way, the effect of using the above-mentioned non-aqueous electrolyte solution 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 reduced 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 (Positive Temperature Coafficient), which increases resistance when abnormal heat generation or excessive current flows, a thermal fuse, thermistor, and cuts off the current flowing in the circuit due to a sudden rise in battery internal pressure or internal temperature during abnormal heat generation. A valve (current cutoff valve) or the like can be used. It is preferable to select the protective element under conditions that do not operate under normal use of high current, and from the viewpoint of high output, it is more preferable to design the protective element so as not to cause abnormal heat generation or thermal runaway even without the protective element.

[Exterior body]
The non-aqueous electrolyte battery of the present embodiment is usually configured by storing 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, nickel-plated steel plates, stainless steel, aluminum or aluminum alloys, magnesium alloys, metals such as nickel and titanium, or laminated films (laminated films) of resin and aluminum foil are 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 collecting terminal to form a closed structure, the metal and the resin are bonded to each other. Resin is preferably used.

Further, the shape of the exterior body is also arbitrary, and may be any of, for example, a cylindrical type, a square type, a laminated type, a coin type, and a large size.

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.

The compounds used in this example and comparative examples are shown below.

<Examples 1 and 2, Comparative Examples 1 and 3>
[Preparation of positive electrode]
90 parts by mass of lithium-nickel-cobalt-manganese composite oxide (Li _1.0 Ni _0.5 Co _0.2 Mn _0.3 O ₂ ) as a positive electrode active material, and 7 parts by mass of acetylene black as a conductive material. 3 parts by mass of polyvinylidene fluoride (PVdF) as a coating agent was mixed with a disperser in an N-methylpyrrolidone solvent to form a slurry. This was uniformly applied to both sides of an aluminum foil having a thickness of 15 μm, dried, and then pressed to obtain a positive electrode.

[Preparation of negative electrode]
98 parts by mass of natural graphite, 1 part by mass of aqueous dispersion of sodium carboxymethyl cellulose (concentration of sodium carboxymethyl cellulose 1% by mass) and aqueous dispersion of styrene-butadiene rubber (styrene-butadiene rubber) as a thickener and binder. 1 part by mass was added, and the mixture was mixed with a disperser to form a slurry. The obtained slurry was applied to one side of a copper foil having a thickness of 10 μm, dried, and then pressed to obtain a negative electrode.

[Preparation of non-aqueous electrolyte solution]
LiPF sufficiently dried as an electrolyte in a mixture of ethylene carbonate (EC), diethyl carbonate (DEC), and ethyl methyl carbonate (EMC) (volume ratio EC: DEC: EMC = 3: 3: 4) under a dry argon atmosphere. ₆ was dissolved in 1.2 mol / L (14.8 mass%, as a concentration in a non-aqueous electrolyte solution), and vinylene carbonate (VC) and fluoroethylene carbonate (FEC) were each 2.0 mass% (non-aqueous). It was added (as the concentration in the aqueous electrolyte) (hereinafter, this is referred to as the reference electrolyte 1). Compounds 1 and 2 were added to the reference electrolytic solution 1 so as to have the contents shown in Table 1 below to prepare non-aqueous electrolytic solutions of Examples 1 and 2 and Comparative Examples 1 to 3. The "content (% by mass)" in the table is the content when the total amount of each non-aqueous electrolyte solution is 100% by mass. Further, "a compound having a Si-O structure represented by the general formula (A) or (B)" is a "Si-O compound", and "a compound represented by the general formula (α)" is a "compound (α)". It was written.

[Manufacturing of non-aqueous electrolyte batteries]
The above positive electrode, negative electrode and polyethylene separator were laminated in this order of negative electrode, separator and 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 so that the positive electrode and negative electrode terminals project from each other, the prepared non-aqueous electrolyte solution is put in the bag. It was injected into the battery and vacuum-sealed to prepare a laminated non-aqueous electrolyte battery.

<Evaluation of non-aqueous electrolyte batteries>
[Initial conditioning]
A non-aqueous electrolyte battery produced by the above method in a constant temperature bath at 25 ° C. has a current corresponding to 0.1 C (1 C means a current value that takes 1 hour to charge or discharge. The same shall apply hereinafter). After constant current charging to 3.2 V, constant current-constant voltage charging (hereinafter referred to as CC-CV charging) was performed to 4.2 V at 0.2 C. Then, it was held at 45 ° C. for 120 hours and aged. Then, it was discharged to 2.5V at 0.2C to stabilize the non-aqueous electrolyte battery. Further, CC-CV charging was performed at 0.2 C to 4.2 V, and then discharged to 2.5 V at 0.2 C for initial conditioning.
The non-aqueous electrolyte battery after the initial conditioning was CC-CV charged at 0.2 C so as to have a capacity half of the initial discharge capacity. This was discharged at 25 ° C. at 1.0 C, 2.0 C, and 3.0 C, respectively, and the voltage at 5 seconds was measured. The average value of the slopes of the current-voltage straight lines at 1.0C, 2.0C, and 3.0C obtained was taken as the battery internal resistance.

<Evaluation of non-aqueous electrolyte batteries>
[High temperature storage test]
The laminated non-aqueous electrolyte battery after the initial conditioning was charged again with CC-CV at 0.2 C to 4.2 V, and then stored at a high temperature at 60 ° C. for 336 hours.
In addition, the non-aqueous electrolyte battery after the storage test is discharged to 2.5 V at 0.2 C, and CC-CV is charged so that the capacity becomes half of the initial discharge capacity at 0.2 C, and the inside of the battery after the storage test is performed. I asked for resistance. The "internal resistance increase rate" before and after high temperature storage was calculated from the following formula (4).
Internal resistance increase rate = [(Internal resistance after storage test) / (Internal resistance after initial conditioning)] x 100% (4)
Table 1 below shows the ratio of the internal resistance increase rates of each example and the comparative example when the internal resistance increase rate of Comparative Example 1-1 is set to 100.

As is clear from Table 1, as in Examples 1 and 2, the compound having the Si—O structure represented by the general formula (A) or (B) of the compound 1 and the like and the general formula (α) of the compound 2 and the like. ), It can be seen that the increase in internal resistance after high-temperature storage is suppressed as compared with the case where each of them is contained alone as in Comparative Examples 1 to 3.

According to the non-aqueous electrolyte solution according to the present invention, an increase in internal resistance of the non-aqueous electrolyte battery during high-temperature storage can be suppressed, and in particular, deterioration of a battery having a high capacity can be improved, which is useful.
Further, the non-aqueous electrolyte solution according to the present invention and the non-aqueous electrolyte battery using the non-aqueous electrolyte solution can be used for various known applications in which the non-aqueous electrolyte battery is used. Specific examples include, for example, laptop computers, pen input computers, mobile computers, electronic book players, mobile phones, mobile fax machines, mobile copy machines, 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, bikes, motorized bicycles, bicycles, lighting fixtures, toys, game consoles, watches, power tools, strobes, cameras, household backups Examples include a power source, a backup power source for business establishments, a power source for load leveling, a natural energy storage power source, and a lithium ion capacitor.

Claims (7)

A non-aqueous electrolyte solution for a non-aqueous electrolyte battery having a positive electrode and a negative electrode capable of occluding and releasing metal ions, wherein the non-aqueous electrolyte solution is represented by the general formula (A) together with an alkali metal salt and a non-aqueous solvent. It is characterized by containing a compound having at least one Si—O structure selected from the compound represented by the general formula (B) and the compound represented by the general formula (α). Non-aqueous electrolyte solution.

(In the formula (A), R ^{1 to} R ³ each independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a substituent. It represents an alkoxy group having 1 to 12 carbon atoms, and X is a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a silyl group represented by ^{−SiR o} R ^p R ^q. R ^{o to} R ^q each independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a hydrocarbon group which may have a substituent. 1 to 12 alkoxy groups are shown.)

(In the formula (B), R ^{4 to} R ⁵ each independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a substituent. It indicates an alkoxy group having 1 to 12 carbon atoms which may be used, and k indicates an integer of 3 to 6).

(In the formula (α), R ^{6 to} R ⁸ each independently have a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, or a substituent. The alkoxy groups having 1 to 12 carbon atoms may be shown. R ^{9 to} R ¹³ are hydrocarbon groups having 1 to 12 carbon atoms which may independently have a hydrogen atom, a halogen atom and a substituent. An alkoxy group having 1 to 12 carbon atoms which may have a substituent or a silyloxy group represented by ^{−OSiR r} R ^s R ^{t. R r to} R ^t each independently have a substituent. Indicates a hydrocarbon group having 1 to 12 carbon atoms which may be used, or an alkoxy group having 1 to 12 carbon atoms which may have a substituent. Y has a single bond, an oxygen atom, or a substituent. Indicates an alkylene group having 1 to 6 carbon atoms which may be present.) The content of the compound having the Si—O structure is 1.0 × 10 with respect to the total amount of the non-aqueous electrolyte solution.
The non-aqueous electrolyte solution according to claim 1, which is ^{-3% by mass to 10% by mass.} The non-aqueous electrolysis according to claim 1 or 2, wherein the content of the compound represented by the general formula (α) is 0.01 mass ppm or more and less than 0.5 mass% with respect to the total amount of the non-aqueous electrolytic solution. liquid. Is 1.0 or more 1.0 × 10 ⁴ or less the ratio of the content of the compound having the Si-O structure to the content of the compound represented by formula in the non-aqueous electrolyte solution (alpha), wherein Item 1
The non-aqueous electrolyte solution according to any one of 3 to 3. The non-aqueous electrolyte solution according to any one of claims 1 to 4, wherein ^{at least one of R 1 to} R ³ is a hydrocarbon group having a carbon-carbon unsaturated bond and having 2 to 12 carbon atoms. R ^{6 to} R ⁸ are each independently a hydrocarbon group having 1 to 12 carbon atoms which may have a substituent or an alkoxy group having 1 to 12 carbon atoms which may have a substituent. The non-aqueous electrolyte solution according to any one of claims 1 to 5. The non-aqueous electrolyte battery comprising a positive electrode and a negative electrode capable of occluding and releasing metal ions and a non-aqueous electrolyte solution, wherein the non-aqueous electrolyte solution is the non-aqueous electrolyte battery according to any one of claims 1 to 6. A non-aqueous electrolyte battery that is an electrolyte.