JP2021082556A - Nonaqueous electrolytic solution and energy device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-aqueous electrolyte solution capable of improving the initial capacity of an energy device and suppressing the decrease in capacity after high temperature storage durability. A non-aqueous electrolyte solution for an energy device including a positive electrode and a negative electrode, wherein the non-aqueous electrolyte solution is a cyclohexane saturated hydrocarbon group R1-containing diisocyanate having a cis structure together with an electrolyte and a non-aqueous solvent. The mass ratio of the content of diisocyanate having a saturated hydrocarbon group R2-containing diisocyanate having a trans structure and (B) cis structure to the content of diisocyanate having a trans structure is 30/70 to 99 /. A non-aqueous electrolyte solution, characterized in that it is 1. The two R1s of the diisocyanate are the same group and represent saturated hydrocarbon groups having 1 to 5 carbon atoms, and the two R2s are the same group and represent saturated hydrocarbon groups having 1 to 5 carbon atoms. show. [Selection diagram] None

Description

The present invention relates to non-aqueous electrolytes and energy devices.

Lithium primary batteries, lithium secondary batteries, and electric double-layer capacitors are 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. , Lithium ion capacitors and other energy devices have been put into practical use. However, the demand for higher performance of energy devices in recent years is increasing.

In particular, 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, in Patent Document 1, by using an electrolytic solution for a non-aqueous electrolyte battery containing a diisocyanate having one cycloalkylene group having 4 to 6 carbon atoms and a cyclic carbonate having a fluorine atom, the capacity at high temperature storage is used. A study for suppressing deterioration and capacitance deterioration during a cycle and improving charge / discharge characteristics under a high current density has been disclosed. However, the document does not mention any steric isomers such as cis-trans structure in isocyanate compounds.
Patent Document 2 describes an electrolytic solution for a non-aqueous electrolyte battery, a synthetic rubber adhesive, and a thickener containing a compound having at least one tertiary or quaternary carbon atom and having a plurality of isocyanate groups. A study for improving capacity deterioration during high-temperature storage and charge / discharge characteristics under high current density by using a negative electrode for a non-aqueous electrolyte battery contained in a specific ratio has been disclosed. However, the document does not mention any steric isomers such as cis-trans structure in isocyanate compounds.
Patent Document 3 examines the synthesis of the diisocyanate component of polyurethane for golf balls, and uses 1,3-bis (aminomethyl) cyclohexane (manufactured by Tokyo Chemical Industry Co., Ltd.) as a raw material for 1,3-bis (aminomethyl) cyclohexane (manufactured by Tokyo Chemical Industry Co., Ltd.). An example is disclosed in which isocyanatomethyl) cyclohexane is synthesized at an isomer ratio (molar ratio) cis form: trans form = 26:74.

Japanese Unexamined Patent Publication No. 2013-51198 Japanese Unexamined Patent Publication No. 2014-41819 Japanese Patent Application Laid-Open No. 2013-42959 Public Relations

In recent years, the increase in capacity of lithium batteries has been accelerated in power sources for vehicles such as electric vehicles and mobile phones such as smartphones, and the proportion of voids in the batteries has become smaller than in the past. Therefore, in particular, there is an increasing demand for improving the initial capacity and suppressing the decrease in capacity after high temperature storage durability.
In view of the above, it is an object of the present invention to provide a non-aqueous electrolyte solution capable of improving the initial capacity of an energy device and suppressing a decrease in capacity after high temperature storage durability. Another object of the present invention is to provide an energy device having a large initial capacity and suppressing a decrease in capacity after high temperature storage durability.

As a result of diligent studies to solve the above problems, the present inventor has improved the initial capacity of the energy device and stored it at a high temperature by using a non-aqueous electrolyte solution containing a plurality of diisocyanate compounds having different three-dimensional structures in a specific ratio. We have found that it is possible to suppress a decrease in capacity after durability, and have reached the present invention.

（式（１）中、２つのＲ^１は、それぞれ同一の基であり、炭素数１〜５の飽和炭化水素基を表し、式（２）中、２つのＲ^２は、それぞれ同一の基であり、炭素数１〜５の飽和炭化水素基を表す。）
＜２＞
前記式（１）中のＲ^１及び式（２）中のＲ^２が同一の基である、＜１＞に記載の非水系電解液。
＜３＞
前記非水系電解液全量に対する前記式（１）で表される化合物ならびに前記式（２）で表される化合物の総含有量が０．００１質量％以上５質量％以下である、＜１＞または＜２＞に記載の非水系電解液。
＜４＞
前記非水系溶媒が鎖状カルボン酸エステルを含有する、＜１＞〜＜３＞のいずれかに記載の非水系電解液。
＜５＞
前記鎖状カルボン酸エステルの非水系溶媒全量に対する含有量が１体積％以上５０体積％以下である、＜４＞に記載の非水系電解液。
＜６＞
前記電解質として、ＬｉＰＦ_６を含有し、ＬｉＰＦ_６の含有量に対する、前記式（１）で表される化合物ならびに前記式（２）で表される化合物の総含有量の質量比が、０．０
０００５以上０．１以下である、＜１＞〜＜５＞のいずれかに記載の非水系電解液。
＜７＞
前記非水系電解液が、更に、炭素−炭素不飽和結合を有する環状カーボネート、フッ素含有環状カーボネート、リチウムイミド塩、モノフルオロリン酸塩及びジフルオロリン酸塩からなる群より選ばれる少なくとも１種の化合物を含有する、＜１＞〜＜６＞のいずれかに記載の非水系電解液。
＜８＞
前記炭素−炭素不飽和結合を有する環状カーボネート、フッ素含有環状カーボネート、リチウムイミド塩、モノフルオロリン酸塩及びジフルオロリン酸塩からなる群より選ばれる少なくとも１種の化合物の非水系電解液全量に対する合計含有量が、０．００１質量％以上１０質量％以下である、＜７＞に記載の非水系電解液。
＜９＞
前記電解質として、ＬｉＰＦ_６を含有し、ＬｉＰＦ_６の含有量に対する、前記炭素−炭素不飽和結合を有する環状カーボネート、フッ素含有環状カーボネート、リチウムイミド塩、モノフルオロリン酸塩及びジフルオロリン酸塩からなる群より選ばれる少なくとも１種の化合物の含有量の質量比が、０．００００５以上０．５以下である、＜７＞または＜８＞に記載の非水系電解液。
＜１０＞
負極、正極及び＜１＞〜＜９＞のいずれかに記載の非水系電解液を含む、エネルギーデバイス。 That is, the present invention includes the following.
<1>
A non-aqueous electrolyte solution for an energy device including a positive electrode and a negative electrode, wherein the non-aqueous electrolyte solution is used together with an electrolyte and a non-aqueous solvent.
(A) A diisocyanate having a cis structure represented by the formula (1) and a diisocyanate having a trans structure represented by the formula (2) are contained and
(B) The mass ratio of the content of the diisocyanate having the cis structure represented by the formula (1) to the content of the diisocyanate having the trans structure represented by the formula (2) is 30/70 to 99/1. ,
A non-aqueous electrolyte solution characterized by this.

(In the formula (1), the two R ^1s are each the same group and represent a saturated hydrocarbon group having 1 to 5 carbon atoms, and in the formula (2), the two R ^2s are each the same group. Represents a saturated hydrocarbon group having 1 to 5 carbon atoms.
<2>
The non-aqueous electrolyte solution according to <1>, ^{wherein R 1} in the formula (1) ^{and R 2} in the formula (2) are the same group.
<3>
The total content of the compound represented by the formula (1) and the compound represented by the formula (2) with respect to the total amount of the non-aqueous electrolyte solution is 0.001% by mass or more and 5% by mass or less, <1> or The non-aqueous electrolyte solution according to <2>.
<4>
The non-aqueous electrolyte solution according to any one of <1> to <3>, wherein the non-aqueous solvent contains a chain carboxylic acid ester.
<5>
The non-aqueous electrolyte solution according to <4>, wherein the content of the chain carboxylic acid ester with respect to the total amount of the non-aqueous solvent is 1% by volume or more and 50% by volume or less.
<6>
Wherein as the electrolyte, containing LiPF _6, to the content of LiPF _6, the mass ratio of the total content of the above formula (1) compound represented by and compounds represented by the formula (2) is 0.0
The non-aqueous electrolyte solution according to any one of <1> to <5>, which is 0005 or more and 0.1 or less.
<7>
The non-aqueous electrolyte solution further comprises at least one compound selected from the group consisting of a cyclic carbonate having a carbon-carbon unsaturated bond, a fluorine-containing cyclic carbonate, a lithium imide salt, a monofluorophosphate and a difluorophosphate. The non-aqueous electrolyte solution according to any one of <1> to <6>, which contains.
<8>
Total of at least one compound selected from the group consisting of cyclic carbonate having a carbon-carbon unsaturated bond, fluorine-containing cyclic carbonate, lithium imide salt, monofluorophosphate and difluorophosphate with respect to the total amount of the non-aqueous electrolyte solution. The non-aqueous electrolyte solution according to <7>, wherein the content is 0.001% by mass or more and 10% by mass or less.
<9>
The electrolyte _{contains LiPF 6} and is composed of a cyclic carbonate having a carbon-carbon unsaturated bond, a fluorine-containing cyclic carbonate, a lithium imide salt, a monofluorophosphate and a difluorophosphate with respect to the content of _{LiPF 6.} The non-aqueous electrolyte solution according to <7> or <8>, wherein the mass ratio of the content of at least one compound selected from the group is 0.00005 or more and 0.5 or less.
<10>
An energy device comprising a negative electrode, a positive electrode, and the non-aqueous electrolyte solution according to any one of <1> to <9>.

According to the present invention, it is possible to provide a non-aqueous electrolyte solution capable of improving the initial capacity of an energy device and suppressing a decrease in capacity after high temperature storage durability. Further, by using such a non-aqueous electrolyte solution, it is possible to provide an energy device having a large initial capacity and suppressed capacity decrease after high temperature storage durability.

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 embodiment of the present invention contains a diisocyanate having a cis structure represented by the formula (1) described below and a diisocyanate having a trans structure represented by the formula (2) in a specific ratio. To do.

So far, attempts have been made to improve the characteristics of energy devices by using diisocyanate. For example, in Patent Document 1 or 2, it is mentioned that the isocyanate compound forms a film on the negative electrode. However, since the film is a polymer, it is considered that the three-dimensional structure and the degree of polymerization of the polymer change due to the change in the ratio of the three-dimensional isomers, but these are not mentioned in the document.
For example, since the diisocyanate having the cis structure represented by the formula (1) is a molecule having plane symmetry, the reactivity of the two isocyanate sites is equivalent. Therefore, the reaction at the time of forming the composite film proceeds uniformly and continuously, so that the composite film having a high degree of polymerization is formed. However, if the degree of polymerization is too high, the bulk of the composite coating itself becomes large, and the three-dimensional repulsion between the coatings makes it impossible to sufficiently cover the negative electrode. In addition, the higher degree of polymerization inhibits the insertion and desorption of lithium ions, thereby lowering the energy device characteristics. Therefore, the diisocyanate having the cis structure represented by the formula (1) alone is not sufficient for the improvement effect of the coating film.
On the other hand, since the diisocyanate having the trans structure represented by the formula (2) does not have plane symmetry, the reactivity of the two isocyanate sites is unequal. Therefore, the reaction proceeds non-uniformly, but the reaction proceeds slowly, and a film having a low degree of polymerization is formed. A film having a low degree of polymerization has high solubility in an electrolytic solution and cannot stably exist on the negative electrode. Therefore, the diisocyanate having the trans structure represented by the formula (2) alone is not sufficient for the improvement effect of the coating film.

In the present invention, paying attention to this point, by mixing isocyanate isomers having different three-dimensional structures at a specific ratio, the degree of polymerization and the three-dimensional structure are optimally adjusted, and a uniformly stable film is formed on the surface of the negative electrode. I found. It was also confirmed that the previously known isomer ratio described in Patent Document 3 has a small improvement effect and is unsuitable as a characteristic.

A method for incorporating an additive such as diisocyanate having a cis structure represented by the formula (1) into the non-aqueous electrolyte solution according to the embodiment of the present invention (hereinafter, also referred to as “combined additive”) , There are no particular restrictions. In addition to the method of directly adding the following compound to the electrolytic solution, a method of generating a combined additive in an energy device or an electrolytic solution can be mentioned. Examples of the method for generating the combined additive include a method in which a compound other than the combined additive is added to oxidize or hydrolyze an energy device component such as an electrolytic solution. Further, there is also a method of producing an energy device and generating it by applying an electric load such as charging / discharging.

Further, when the combined additive is contained in the non-aqueous electrolyte solution and actually used for manufacturing the energy device, even if the energy device is disassembled and the non-aqueous electrolyte solution is extracted again, the content in the non-aqueous electrolyte solution is significantly reduced. In many cases. Therefore, it is considered that the non-aqueous electrolyte solution extracted from the energy device includes the one that can detect even a very small amount of the combined additive in the present invention. Further, when the combined additive was actually used as a non-aqueous electrolyte solution for manufacturing an energy device, the non-aqueous electrolyte solution obtained by disassembling the energy device and extracting it again contained only a very small amount of the combined additive. Even in this case, it is often detected on the positive electrode, the negative electrode, or the separator, which are other components of the energy device. Therefore, when the combined additive is detected from the positive electrode, the negative electrode, and the separator, it can be assumed that the total amount is contained in the non-aqueous electrolyte solution. Under this assumption, the combined additives are preferably contained within the range described below.

<1-1. Diisocyanate having a cis structure represented by the formula (1) and diisocyanate having a trans structure represented by the formula (2)>
The non-aqueous electrolyte solution of the present embodiment is characterized by containing a diisocyanate having a cis structure represented by the following formula (1) and a diisocyanate having a trans structure represented by the formula (2).

(In the formula (1), the two R ^1s are each the same group and represent a saturated hydrocarbon group having 1 to 5 carbon atoms, and in the formula (2), the two R ^2s are each the same group. Represents a saturated hydrocarbon group having 1 to 5 carbon atoms.

^{R 1} in the formula (1) ^{and R 2} in the formula (2) may be the same group or different groups, but if they are the same group, the film forming reaction is efficient. This is preferable because the synergistic effect when the compound represented by the formula (1) and the compound represented by the formula (2) are added in combination is likely to be exhibited.

R ¹ and R ² are not particularly limited as long as they are saturated hydrocarbon groups having 1 or more and 5 or less carbon atoms, and may have substituents, preferably saturated hydrocarbon groups having 1 or more and 3 or less carbon atoms. is there. The number of carbon atoms in the main chain of the saturated hydrocarbon group is usually 1 or more, preferably 5 or less, and more preferably 3 or less. When the ^{number of carbon atoms in the main chain of the saturated hydrocarbon group represented by R 1} and R ² is in this range, the characteristic difference between the stereoisomers is likely to appear, and when a plurality of stereoisomers are used in combination. The synergistic improvement effect of is more remarkable.

Examples of the saturated hydrocarbon group include an alkylene group and a cycloalkylene group, and an alkylene group is preferable. Examples of the alkylene group include a methylene group which may have a substituent, an ethylene group, a trimethylene group, a tetramethylene group and a pentamethylene group, and preferably a methylene group and an ethylene group which may have a substituent. Alternatively, it is a methylene group, more preferably a methylene group which may have a substituent, and further preferably a methylene group which does not have a substituent. Since it is a methylene group, a film is efficiently formed, and the synergistic effect when a plurality of stereoisomers are used is more remarkable.

As a substituent that the saturated hydrocarbon group may have,
A linear chain having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a cyclopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and a cyclobutyl group. , Branched, or cyclic alkyl group;
Alkoxy groups having 1 or more and 4 or less carbon atoms, such as methoxy groups and ethoxy groups;
Halogen atoms such as fluorine atom, chlorine atom, bromine atom, iodine atom;
And so on. Of these, the substituent is preferably an alkyl group, more preferably a methyl group.
The carbon number of the saturated hydrocarbon group described above includes the carbon number of the substituent.

Specific examples of the diisocyanate having a cis structure represented by the formula (1) include the following.

Specific examples of the diisocyanate having a trans structure represented by the formula (2) include the following.

The mass ratio of the content of the diisocyanate having the cis structure represented by the formula (1) to the content of the diisocyanate having the trans structure represented by the formula (2) is usually 30/70 or more, preferably 51. / 49 or more, more preferably 68/32, still more preferably 73/27, usually 99/1 or less, preferably 90/10, more preferably 84/16, still more preferably 80/20, particularly preferably. Is 78/12. When the mass ratio is within this range, the three-dimensional structure and degree of polymerization of the polymer to be formed are suitable as a coating film, and the entire negative electrode surface is uniformly stable and of good quality without inhibiting the insertion and desorption of lithium ions. It can be covered, and the effect of improving the characteristics of the energy device is remarkably exhibited. Gas chromatography (GC) analysis can be mentioned as a method for measuring the content ratio (mass ratio) of the diisocyanate having a cis structure represented by the formula (1) and the diisocyanate having a trans structure represented by the formula (2). ..

The content of the diisocyanate having a cis structure represented by the formula (1) or the diisocyanate having a trans structure represented by the formula (2) is not particularly limited, but is represented by the formula (1) with respect to the total amount of the non-aqueous electrolyte solution. The content of the diisocyanate having a cis structure or the diisocyanate having a trans structure represented by the formula (2) is usually 0.001% by mass or more, preferably 0.01% by mass or more, and more preferably 0.1% by mass. % Or more, more preferably 0.2% by mass or more, particularly preferably 0.5% by mass or more, and usually 5% by mass or less, preferably 3% by mass or less, still more preferably 1% by mass or less. Particularly preferably, it is 0.8% by mass or less. When the content of each of these diisocyanates is within this range, the resistance increase is small and the effect of the invention is remarkably exhibited.

The total content of the diisocyanate having a cis structure represented by the formula (1) and the diisocyanate having a trans structure represented by the formula (2) is not particularly limited, but the formula (1) with respect to the total amount of the non-aqueous electrolyte solution is used. The total content of the diisocyanate having the cis structure represented by the cis structure and the diisocyanate having the trans structure represented by the formula (2) is usually 0.001% by mass or more, preferably 0.01% by mass or more, and more preferably 0. .1% by mass or more, more preferably 0.2% by mass or more, particularly preferably 0.5% by mass or more, and usually 5% by mass or less, preferably 3% by mass or less, still more preferably 1% by mass. % Or less, particularly preferably 0.8% by mass or less. When the total content of these diisocyanates is within this range, the resistance increase is small and the effect of the invention is remarkably exhibited.
Gas chromatography (GC) analysis can be mentioned as a method for measuring the content of the diisocyanate having a cis structure represented by the formula (1) and the diisocyanate having a trans structure represented by the formula (2).

<1-2. 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.

<1-2-1. 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 and FSO _{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 LiB (C ₂ O ₄ ) _2;
In addition, fluorine-containing organic lithium salts such as _{LiPF 4} (CF ₃ ) _2;
And so on.

In addition to improving the charge storage characteristics of the energy device in a high temperature environment, the electrolyte in the non-aqueous electrolyte solution of the present embodiment is an inorganic lithium salt or fluorophosphate from the viewpoint of further enhancing the effect of improving the charge / discharge rate characteristics and impedance characteristics. Those selected from lithium salts, sulfonic acid lithium salts, lithium imide salts, and lithium oxalate salts are preferable. Of these, preferably at least one selected from _{LiPF 6} , LiBF ₄ , LiClO ₄ , LiB (C ₂ O ₄ ) ₂ , Li (FSO ₂ ) ₂ N and Li (CF ₃ SO ₂ ) _{2 N.} More preferred _{is at least one selected from LiPF 6} , LiBF ₄ , Li (FSO ₂ ) ₂ N and Li (CF ₃ SO ₂ ) ₂ N, and even more preferred are LiPF ₆ and Li (FSO ₂ ) _2. At least one of N, particularly preferred is LiPF ₆ . The above-mentioned lithium salts may be used alone or in combination of two or more.

The total concentration of these electrolytes in the non-aqueous electrolyte solution is not particularly limited, but when a lithium salt is used as the main salt of the electrolyte solution, it is usually 8% by mass or more, preferably 8% by mass or more, based on the total amount of the non-aqueous electrolyte solution. It is 8.5% by mass or more, more preferably 9% by mass or more. Further, it is usually 20% 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 the operation of the energy device, so that sufficient output characteristics tend to be obtained. When a lithium salt is used as a by-salt, the concentration of the lithium salt is usually 0.05% by mass or more, preferably 0.1% by mass or more, and more preferably 0, based on the total amount of the non-aqueous electrolyte solution. .2% by mass or more, more preferably 0.3% by mass or more, particularly preferably 0.4% by mass or more, and usually 2% by mass or less, particularly preferably 1% by mass or less. When the concentration of the lithium salt is within this range, there are few side reactions in the energy device and it is difficult to increase the resistance.

In case of having a LiPF ₆ in a non-aqueous electrolyte solution, assumes that all PF ₆ anion is derived from LiPF _6, compounds represented by the formula to the content of LiPF ₆ was calculated therefrom (1) and the formula ( The mass ratio of the total content of the compound represented by 2) is usually 0.00005 or more, preferably 0.001 or more, more preferably 0.01 or more, still more preferably 0.02 or more, and particularly preferably 0. It is 025 or more, usually 0.1 or less, preferably 0.08 or less, more preferably 0.06 or less, still more preferably 0.04 or less. When _{the content of LiPF 6} is in this range, the characteristics of the energy device, particularly the durability characteristics, can be remarkably improved. Although the principle is not clear, it is considered that the decomposition side reaction _{of LiPF 6 in the energy device system can be minimized by mixing at this ratio.}
Similarly, in the following, the mass _{of LiPF 6} in the non-aqueous electrolyte solution is considered to be derived from LiPF _{6 for all PF 6} anions, and is regarded as the mass calculated from the mass.

<1-3. Non-aqueous solvent>
Like a general non-aqueous electrolyte solution, the non-aqueous electrolyte solution usually contains a non-aqueous solvent that dissolves the above-mentioned electrolyte as its main component. The non-aqueous solvent used here is not particularly limited, and a known organic solvent can be used. The organic solvent is not particularly limited, and examples thereof include saturated cyclic carbonates, chain carbonates, chain carboxylic acid esters, ether compounds, sulfone compounds, and cyclic carboxylic acid esters. Of these, the organic solvent is preferably at least one selected from saturated cyclic carbonate, chain carbonate and chain carboxylic acid ester, and at least chain carboxylic acid in that the initial capacity of the energy device can be easily improved. More preferably, it contains an acid ester. These can be used individually by 1 type or in combination of 2 or more types. Hereinafter, these organic solvents will be described.

<1-3-1. 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 energy device characteristics resulting from an improvement in the degree of lithium ion dissociation. Be done.

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 effects of the invention according to the present embodiment are not significantly impaired, but the lower limit of the content when one of them is used alone is the non-aqueous electrolyte solution. It is usually 3% by volume or more, preferably 5% by volume or more, based on the total amount of the solvent. By setting the lower limit of the content of saturated cyclic carbonate 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 a large energy device such as a non-aqueous electrolyte secondary battery. It becomes easy to set the current discharge characteristics, stability with respect to the negative electrode, and cycle characteristics in a good range. The upper limit of the content of the saturated cyclic carbonate is usually 90% by volume or less, preferably 85% by volume or less, and more preferably 80% by volume or less with respect to the total amount of the solvent of the non-aqueous electrolyte solution. 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 this embodiment means the volume at 25 ° C. and 1 atm.

<1-3-2. 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. is there.

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. Fluoroethyl methyl carbonate, 2,2-difluoroethyl fluoromethyl carbonate, 2-fluoroethyl difluoromethyl carbonate, ethyl trifluoromethyl carbonate and the like can be mentioned.

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, more preferably 25% by volume or more, and more preferably 25% by volume or more, based on the total amount of the solvent of the non-aqueous electrolyte solution. It is usually 90% by volume or less, preferably 85% by volume or less, and more preferably 80% by volume or less. By setting the content of the chain carbonate in the above range, the viscosity of the non-aqueous electrolyte solution is set in an appropriate range, the decrease in ionic conductivity is suppressed, and the output characteristics of the energy device such as the non-aqueous electrolyte secondary battery. Is easy to set in a good range.

Further, by combining ethylene carbonate with a specific chain carbonate in a specific content, the energy device performance can be remarkably improved.

For example, when dimethyl carbonate and ethyl methyl carbonate are selected as the specific chain carbonate, the content of ethylene carbonate is not particularly limited and is arbitrary as long as the effect of the invention according to the present embodiment 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 of the aqueous electrolytic solution, and the content of dimethyl carbonate is non-aqueous electrolytic solution. 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 ethyl methyl carbonate is usually 20% by volume or more with respect to the total amount of the solvent of the liquid. It is preferably 30% by volume or more, and 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.

<1-3-3. Chain Carboxylic Acid Ester>
The chain carboxylic acid ester preferably has 3 to 12 carbon atoms, and more preferably 3 to 5 carbon atoms.
As a chain carboxylic acid ester,
Methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, -tert-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, isopropyl propionate, n-propionate Butyl, isobutyl propionate, -tert-butyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, isobutyl butyrate, -tert-butyl butyrate, methyl isobutyrate, ethyl isobutyrate, iso N-propyl butyrate, isopropyl isobutyrate, n-butyl isobutyrate, isobutyl isobutyrate, -tert-butyl isobutyrate, methyl valerate, ethyl valerate, n-propyl valerate, isopropyl valerate, n-butyl valerate, Isobutyl valerate, -tert-butyl valerate, methyl hydroangelica, ethyl hydroangelica, n-propyl hydroangelica, isopropyl hydroangelica, n-butyl hydroangelica, isobutyl hydroangelica, hydroangelica-tert -Butyl, methyl isovalerate, ethyl isovalerate, n-propyl isovalerate, isopropyl isovalerate, n-butyl isovalerate, isobutyl isovalerate, -tert-butyl isovalerate, methyl pivalate, pival Saturated chain carboxylic acid esters such as ethyl acid, n-propyl pivalate, isopropyl pivalate, n-butyl pivalate, isobutyl pivalate, -tert-butyl pivalate;

Methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, -tert-butyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, methacryl Isopropyl acid, n-butyl methacrylate, isobutyl methacrylate, -tert-butyl methacrylate, methyl crotonate, ethyl crotonate, n-propyl crotonate, isopropyl crotonate, n-butyl crotonate, isobutyl crotonate, crotonic acid -Tert-Butyl, methyl 3-butylate, ethyl 3-butenoate, n-propyl 3-butenoate, isopropyl 3-butylate, n-butyl 3-butylate, isobutyl 3-butylate, 3-butylate- tert-Butyl, methyl 4-pentate, ethyl 4-pentate, n-propyl 4-pentate, isopropyl 4-pentate, n-butyl 4-pentene, isobutyl 4-pentate, -tert -Butyl, Methyl 3-Pentate, Ethyl 3-Pentate, n-propyl 3-Pentate, Isopropyl 3-Pentate, n-Butyl 3-Pentate, Isobutyl 3-Pentate, -tert- Butyl, methyl 2-pentate, ethyl 2-pentate, n-propyl 2-pentate, isopropyl 2-pentate, n-butyl 2-pentate, isobutyl 2-pentate, -tert-butyl 2-pentate , Methyl 2-propate, ethyl 2-propate, n-propyl 2-propate, isopropyl 2-propate, n-butyl 2-propate, isobutyl 2-propate, -tert-butyl 2-propate, Methyl 3-butylate, ethyl 3-butylate, n-propyl 3-butylate, isopropyl 3-butylate, n-butyl 3-butylate, isobutyl 3-butylate, -tert-butyl 3-butylate, 2 -Methyl butynate, ethyl 2-butylate, n-propyl 2-butylate, isopropyl 2-butylate, n-butyl 2-butylate, isobutyl 2-butylate, -tert-butyl 2-butylate, 4- Methyl pentate, ethyl 4-pentate, n-propyl 4-pentate, isopropyl 4-pentinate, n-butyl 4-pentylate, isobutyl 4-pentylate, -tert-butyl 4-pentylate, 3-pentin Methyl Acidate, Ethyl 3-Pentate, n-Pro 3-Pentate Pill, isopropyl 3-pentate, n-butyl 3-pentate, isobutyl 3-pentate, -tert-butyl 3-pentinate, methyl 2-pentate, ethyl 2-pentate, n-propyl 2-pentate , 2-butyl 2-pentate, n-butyl 2-pentate, isobutyl 2-pentate, 2-tert-butyl 2-pentate and other unsaturated chain carboxylic acid esters.

Of these, methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, n-butyl propionate, Methyl butyrate, ethyl butyrate, n-propyl butyrate, n-butyl butyrate, methyl valerate, ethyl valerate, n-propyl valerate, n-butyl valerate, methyl pivalate, ethyl pivalate, n-propyl pivalate or N-butyl pivalate is preferable, and methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, methyl propionate, ethyl propionate, n-propionate are used from the viewpoint of improving ionic conductivity by lowering the viscosity of the electrolytic solution. Methyl acetate, ethyl acetate, methyl propionate and ethyl propionate are more preferred, and methyl acetate or ethyl acetate are particularly preferred.

When the chain carboxylic acid ester is used as the non-aqueous solvent, the content is preferably 1% by volume or more, more preferably 5% by volume or more, still more preferably 10% by volume or more in 100% by volume of the non-aqueous solvent. Further, it can be contained in an amount of 50% by volume or less, more preferably 45% by volume or less, still more preferably 40% by volume or less. When the content of the chain carboxylic acid ester is within the above range, the electrical conductivity of the non-aqueous electrolyte solution can be improved, and the input / output characteristics and charge / discharge rate characteristics of energy devices such as the non-aqueous electrolyte secondary battery can be easily improved. Become. In addition, the increase in negative electrode resistance is suppressed, and the input / output characteristics and charge / discharge rate characteristics of energy devices such as non-aqueous electrolyte secondary batteries can be easily set in a good range.

The mass ratio of the diisocyanate having a cis structure represented by the above formula (1) to the chain carboxylic acid ester (total amount in the case of two or more types) is the diisocyanate / chain having a cis structure represented by the formula (1). The carboxylic acid ester is usually 1/1000 or more, preferably 1/100 or more, more preferably 2/100 or more, still more preferably 3/100 or more, usually 100/100 or less, preferably 50. It is / 100 or less, more preferably 10/100 or less, still more preferably 9/100 or less, particularly preferably 8/100 or less, and most preferably 7/100 or less. When the mass ratio is in this range, the battery characteristics, particularly the durability characteristics, can be remarkably improved. This principle is not clear, but it is thought that by mixing at this ratio, the side reaction of the additive on the electrode can be minimized.

The mass ratio of the diisocyanate having a trans structure represented by the above formula (2) to the chain carboxylic acid ester (total amount in the case of two or more types) is the diisocyanate / chain having a trans structure represented by the formula (2). The carboxylic acid ester is usually 1/1000 or more, preferably 1/100 or more, more preferably 2/100 or more, still more preferably 3/100 or more, usually 100/100 or less, preferably 50. It is / 100 or less, more preferably 10/100 or less, still more preferably 9/100 or less, particularly preferably 8/100 or less, and most preferably 7/100 or less. When the mass ratio is in this range, the energy device characteristics, particularly the durability characteristics, can be remarkably improved. This principle is not clear, but it is thought that by mixing at this ratio, the side reaction of the additive on the electrode can be minimized.

When the chain carboxylic acid ester is used as a non-aqueous solvent, it is preferably used in combination with a cyclic carbonate, and more preferably in combination with a cyclic carbonate and a chain carbonate. While lowering the low-temperature precipitation temperature of the electrolyte, the viscosity of the non-aqueous electrolyte solution is also lowered to improve ionic conductivity, higher input / output can be obtained even at low temperatures, and the swelling of energy devices, especially batteries, is further reduced. Because it can be made to.

<1-3-4. Ether compounds>
As the ether compound, a chain ether having 3 to 10 carbon atoms and a cyclic ether having 3 to 6 carbon atoms are preferable.
Examples of the chain ether having 3 to 10 carbon atoms include diethyl ether, di (2-fluoroethyl) ether, di (2,2-difluoroethyl) ether, di (2,2,2-trifluoroethyl) ether, and ethyl. (2-Fluoroethyl) ether, ethyl (2,2,2-trifluoroethyl) ether, ethyl (1,1,2,2-tetrafluoroethyl) ether, (2-fluoroethyl) (2,2,2) -Trifluoroethyl) ether, (2-fluoroethyl) (1,1,2,2-tetrafluoroethyl) ether, (2,2,2-trifluoroethyl) (1,1,2,2-tetrafluoro) Ethyl) ether, ethyl-n-propyl ether, ethyl (3-fluoro-n-propyl) ether, ethyl (3,3,3-trifluoro-n-propyl) ether, ethyl (2,2,3,3- Tetrafluoro-n-propyl) ether, ethyl (2,2,3,3,3-pentafluoro-n-propyl)
Ether, 2-fluoroethyl-n-propyl ether, (2-fluoroethyl) (3-fluoro-n-propyl) ether, (2-fluoroethyl) (3,3,3-trifluoro-n-propyl) ether , (2-Fluoroethyl) (2,2,3,3-tetrafluoro-n-propyl) ether, (2-fluoroethyl) (2,2,3,3,3-pentafluoro-n-propyl) ether , 2,2,2-Trifluoroethyl-n-propyl ether, (2,2,2-trifluoroethyl) (3-fluoro-n-propyl) ether, (2,2,2-trifluoroethyl) ( 3,3,3-trifluoro-n-propyl) ether, (2,2,2-trifluoroethyl) (2,2,3,3-tetrafluoro-n-propyl) ether, (2,2,2) -Trifluoroethyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, 1,1,2,2-tetrafluoroethyl-n-propyl ether, (1,1,2,2) -Tetrafluoroethyl) (3-fluoro-n-propyl) ether, (1,1,2,2-tetrafluoroethyl) (3,3,3-trifluoro-n-propyl) ether, (1,1,1 2,2-Tetrafluoroethyl) (2,2,3,3-tetrafluoro-n-propyl) ether, (1,1,2,2-tetrafluoroethyl) (2,2,3,3,3- Pentafluoro-n-propyl) ether, di-n-propyl ether, (n-propyl) (3-fluoro-n-propyl) ether, (n-propyl) (3,3,3-trifluoro-n-propyl) ) Ether, (n-propyl) (2,2,3,3-tetrafluoro-n-propyl) ether, (n-propyl) (2,2,3,3,3-pentafluoro-n-propyl) ether , Di (3-fluoro-n-propyl) ether, (3-fluoro-n-propyl) (3,3,3-trifluoro-n-propyl) ether, (3-fluoro-n-propyl) (2, 2,3,3-Tetrafluoro-n-propyl) ether, (3-fluoro-n-propyl) (2,2,3,3,3-pentafluoro-n-propyl) ether, di (3,3) 3-Trifluoro-n-propyl) ether, (3,3,3-trifluoro-n-propyl) (2,2,3,3-tetrafluoro-n-propyl) ether, (3,3,3- Trifluoro-n-propyl) (2,2,3 , 3,3-Pentafluoro-n-propyl) ether, di (2,2,3,3-tetrafluoro-n-propyl) ether, (2,2,3,3-tetrafluoro-n-propyl) ( 2,2,3,3,3-pentafluoro-n-propyl) ether, di (2,2,3,3,3-pentafluoro-n-propyl) ether, di-n-butyl ether, dimethoxymethane, methoxy Ethane, methoxy (2-fluoroethoxy) methane, methoxy (2,2,2-trifluoroethoxy) methanemethoxy (1,1,2,2-tetrafluoroethoxy) methane, diethoxymethane, ethoxy (2-fluoro) Ethane) methane, ethoxy (2,2,2-trifluoroethoxy) methane, ethoxy (1,1,2,2-tetrafluoroethoxy) methane, di (2-fluoroethoxy) methane, (2-fluoroethoxy) ( 2,2,2-trifluoroethoxy) methane, (2-fluoroethoxy) (1,1,2,2-tetrafluoroethoxy) methanedi (2,2,2-trifluoroethoxy) methane, (2,2) 2-Trifluoroethoxy) (1,1,2,2-tetrafluoroethoxy) methane, di (1,1,2,2-tetrafluoroethoxy) methane, dimethoxyethane, methoxyethoxyethane, methoxy (2-fluoroethoxy) ) Ethane, methoxy (2,2,2-trifluoroethoxy) ethane, methoxy (1,1,2,2-tetrafluoroethoxy) ethane, diethoxyethane, ethoxy (2-fluoroethoxy) ethane, ethoxy (2,2) 2,2-Trifluoroethoxy) ethane, ethoxy (1,1,2,2-tetrafluoroethoxy) ethane, di (2-fluoroethoxy) ethane, (2-fluoroethoxy) (2,2,2-trifluoro) Ethoxy) ethane, (2-fluoroethoxy) (1,1,2,2-tetrafluoroethoxy) ethane, di (2,2,2-trifluoroethoxy) ethane, (2,2,2-trifluoroethoxy) (1,1,2,2-Tetrafluoroethoxy) ethane, di (1,1,2,2-tetrafluoroethoxy) ethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, diethylene glycol dimethyl ether And so on.

Among these, dimethoxymethane, diethoxymethane, methoxyethoxymethane, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, and diethylene glycol dimethyl ether have high solvation ability to lithium ions and have ionic dissociability. It is preferable in terms of improvement. Particularly preferred are dimethoxymethane, diethoxymethane, and methoxyethoxymethane because of their low viscosity and high ionic conductivity.

Examples of the cyclic ether having 3 to 6 carbon atoms include tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, 1,3-dioxane, 2-methyl-1,3-dioxane, 4-methyl-1,3-dioxane, and 1 , 4-Dioxane and the like, and fluorinated compounds thereof.

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

<1-3-5. 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.

Among them, 2-methylsulfolane, 3-methylsulfolane, 2-fluorosulfolane, 3-fluorosulfolane, 2,2-difluorosulfolane, 2,3-difluorosulfolane, 2,4-difluorosulfolane, 2,5-difluorosulfolane, 3,4-Difluorosulfolane, 2-fluoro-3-methylsulfolane, 2-fluoro-2-methylsulfolane, 3-fluoro-3-methylsulfolane, 3-fluoro-2-methylsulfolane, 4-fluoro-3-methyl Sulfolane, 4-fluoro-2-methyl sulfolane, 5-fluoro-3-methyl sulfolane, 5-fluoro-2-methyl sulfolane, 2-fluoromethyl sulfolane, 3-fluoromethyl sulfolane, 2-difluoromethyl sulfolane, 3-difluoro Methyl sulfolane, 2-trifluoromethyl sulfolane, 3-trifluoromethyl sulfolane, 2-fluoro-3- (trifluoromethyl) sulfolane, 3-fluoro-3
-(Trifluoromethyl) sulfolane, 4-fluoro-3- (trifluoromethyl) sulfolane, 5-fluoro-3- (trifluoromethyl) sulfolane and the like are preferable because they have high ionic conductivity and high input / output.

Examples of the chain sulfone include dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl methyl sulfone, n-propyl ethyl sulfone, di-n-propyl sulfone, isopropyl methyl sulfone, isopropyl ethyl sulfone, diisopropyl sulfone, and n-. Butylmethylsulfone, n-butylethylsulfone, t-butylmethylsulfone, t-butylethylsulfone, monofluoromethylmethylsulfone, difluoromethylmethylsulfone, trifluoromethylmethylsulfone, monofluoroethylmethylsulfone, difluoroethylmethylsulfone, Trifluoroethyl methyl sulfone, pentafluoroethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, ethyl trifluoromethyl sulfone, perfluoroethyl methyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoroethyl sulfone, di (tri) Fluoroethyl) sulfone, perfluorodiethyl sulfone, fluoromethyl-n-propyl sulfone, difluoromethyl-n-propyl sulfone, trifluoromethyl-n-propyl sulfone, fluoromethyl isopropyl sulfone, difluoromethyl isopropyl sulfone, trifluoromethyl isopropyl sulfone , Trifluoroethyl-n-propyl sulfone, trifluoroethyl isopropyl sulfone, pentafluoroethyl-n-propyl sulfone, pentafluoroethyl isopropyl sulfone, trifluoromethyl-n-butyl sulfone, trifluoromethyl-t-butyl sulfone, tri Fluoroethyl-n-butyl sulfone, trifluoroethyl-t-butyl sulfone, pentafluoroethyl-n-butyl sulfone, pentafluoroethyl-t-butyl sulfone and the like can be mentioned.

Among them, dimethyl sulfone, ethyl methyl sulfone, diethyl sulfone, n-propyl methyl sulfone, isopropyl methyl sulfone, n-butyl methyl sulfone, t-butyl methyl sulfone, monofluoromethyl methyl sulfone, difluoromethyl methyl sulfone, trifluoromethyl methyl sulfone. , Monofluoroethyl methyl sulfone, difluoroethyl methyl sulfone, trifluoroethyl methyl sulfone, pentafluoroethyl methyl sulfone, ethyl monofluoromethyl sulfone, ethyl difluoromethyl sulfone, ethyl trifluoromethyl sulfone, ethyl trifluoroethyl sulfone, ethyl pentafluoro Ethyl sulfone, trifluoromethyl-n-propyl sulfone, trifluoromethyl isopropyl sulfone, trifluoroethyl-n-butyl sulfone, trifluoroethyl-t-butyl sulfone, trifluoromethyl-n-butyl sulfone, trifluoromethyl-t -Butyl sulfone or the like is preferable because it improves the high temperature storage stability of the electrolytic solution.

The content of the sulfone compound is not particularly limited and is arbitrary as long as the effect of the invention according to the present embodiment is not significantly impaired, but is usually 0.3% by volume or more based on the total amount of the solvent of the non-aqueous electrolyte solution. It is preferably 0.5% 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 the content of the sulfone compound is within the above range, an electrolytic solution having excellent high temperature storage stability tends to be obtained.

<1-3-6. Cyclic carboxylic acid ester>
The cyclic carboxylic acid ester preferably has 3 to 12 carbon atoms.
Specific examples thereof include γ-butyrolactone, γ-valerolactone, γ-caprolactone, and ε-caprolactone. Of these, γ-butyrolactone is particularly preferable from the viewpoint of improving energy device characteristics resulting from an improvement in the degree of lithium ion dissociation.

As the cyclic 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 cyclic carboxylic acid ester is preferably 5% by volume or more, more preferably 10% by volume or more in 100% by volume of the non-aqueous solvent. Within this range, the electrical conductivity of the non-aqueous electrolyte solution can be improved, and the large current discharge characteristics of the energy device can be easily improved. The content of the cyclic carboxylic acid ester is preferably 50% by volume or less, more preferably 40% by volume or less. By setting the upper limit in this way, the viscosity of the non-aqueous electrolyte solution is set in an appropriate range, the decrease in electrical conductivity is avoided, the increase in negative electrode resistance is suppressed, and the large current discharge characteristics of the energy device are in a good range. It becomes easy to do.

<1-4. Auxiliary agent>
The non-aqueous electrolyte solution may contain the following auxiliaries as long as the effects of the invention according to the present embodiment are exhibited. The auxiliary agent is not particularly limited, and is, for example, a cyclic carbonate having a carbon-carbon unsaturated bond, a monofluorophosphate and a difluorophosphate, a fluorine-containing cyclic carbonate, a lithiumimide salt, a sulfur-containing organic compound, and a phosphorus-containing organic. Compounds, organic compounds having a cyano group, organic compounds having an isocyanate group other than the compounds represented by the formulas (1) and (2), silicon-containing compounds, borates, oxalates, fluorosulfonates, aromatics. Examples include group carbonates. Among these, the auxiliary agent is selected from cyclic carbonates having carbon-carbon unsaturated bonds, monofluorophosphates and difluorophosphates, fluorine-containing cyclic carbonates, lithium imide salts, fluorosulfonates, and aromatic carbonates. It is preferably at least one, and is at least one selected from cyclic carbonates having carbon-carbon unsaturated bonds, difluorophosphates, fluorine-containing cyclic carbonates, lithium imide salts, fluorosulfonates and aromatic carbonates. It is preferable, and it is more preferable to use these in combination. Alternatively, the auxiliary agent is preferably at least one selected from a cyclic carbonate having a carbon-carbon unsaturated bond and a fluorine-containing cyclic carbonate, and it is more preferable to use these in combination. These can be used individually by 1 type or in combination of 2 or more types. Hereinafter, specific auxiliary agents will be described.

<1-4-1. Cyclic carbonate with carbon-carbon unsaturated bond>
The cyclic carbonate having a carbon-carbon unsaturated bond (hereinafter, also referred to as “unsaturated cyclic carbonate”) is not particularly limited as long as it is a cyclic carbonate having a carbon-carbon double bond or a carbon-carbon triple bond. Cyclic carbonates having an aromatic ring are also included in the unsaturated cyclic carbonates.

Examples of unsaturated cyclic carbonates include vinylene carbonates, aromatic rings, ethylene carbonates substituted with substituents having carbon-carbon double bonds or carbon-carbon triple bonds, phenyl carbonates, vinyl carbonates, allyl carbonates, and the like. Examples thereof include catechol carbonates. Of these, vinylene carbonates, or ethylene carbonates substituted with a substituent having an aromatic ring or a carbon-carbon double bond or a carbon-carbon triple bond are preferable.

Specific examples of the unsaturated cyclic carbonate include vinylene carbonate, methylvinylene carbonate, 4,5-dimethylvinylene carbonate, phenylvinylene carbonate, 4,5-diphenylvinylene carbonate, vinylvinylene carbonate, 4,5-vinylvinylene carbonate, and allyl. Vinylene carbonates such as 4,5-diallyl vinylene carbonate;
Vinyl ethylene carbonate, 4,5-divinylethylene carbonate, 4-methyl-5-vinylethylene carbonate, 4-allyl-5-vinylethylene carbonate, ethynylethylene carbonate, 4,5-dietinylethylene carbonate, 4-methyl-5 -Ethylene ethylene carbonate, 4-vinyl-5-ethynyl ethylene carbonate, 4-allyl-5-ethynyl ethylene carbonate, phenylethylene carbonate, 4,5-
Aromatic rings such as diphenylethylene carbonate, 4-phenyl-5-vinylethylene carbonate, 4-allyl-5-phenylethylene carbonate, allylethylene carbonate, 4,5-diallylethylene carbonate, 4-methyl-5-allylethylene carbonate or the like. Ethylene carbonates substituted with a substituent having a carbon-carbon double bond or a carbon-carbon triple bond;
And so on. Among them, vinylene carbonate, vinylethylene carbonate and ethynylethylene carbonate are preferable because they form a more stable interfacial protective film, vinylene carbonate and vinylethylene carbonate are more preferable, and vinylene carbonate is further preferable.

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 unsaturated cyclic carbonate (total amount in the case of two or more types) can be 0.001% by mass or more, preferably 0.01% by mass or more, based on 100% by mass of the non-aqueous electrolyte solution. It is preferably 0.1% by mass or more, and can be 5% by mass or less, preferably 4% by mass or less, and more preferably 3% by mass or less. When the content of unsaturated cyclic carbonate is within this range, energy devices such as non-aqueous electrolyte batteries are likely to exhibit a sufficient effect of improving cycle characteristics, and the high temperature storage characteristics are lowered, resulting in a large amount of gas generated. Therefore, it is easy to avoid a situation in which the discharge capacity retention rate is lowered.

The mass ratio of the diisocyanate having the cis structure represented by the above formula (1) to the unsaturated cyclic carbonate (total amount in the case of two or more types) is the diisocyanate having the cis structure represented by the formula (1) / unsaturated. The cyclic carbonate is usually 1/100 or more, preferably 10/100 or more, more preferably 20/100 or more, still more preferably 25/100 or more, usually 10000/100 or less, preferably 500/100. Below, it is more preferably 300/100 or less, still more preferably 100/100 or less, particularly preferably 75/100 or less, and most preferably 50/100 or less. When the mass ratio is in this range, the energy device characteristics, particularly the durability characteristics, can be remarkably improved. This principle is not clear, but it is thought that by mixing at this ratio, the side reaction of the additive on the electrode can be minimized.

The mass ratio of the diisocyanate having the trans structure represented by the above formula (2) to the unsaturated cyclic carbonate (total amount in the case of two or more types) is the diisocyanate having the trans structure represented by the formula (2) / unsaturated. The cyclic carbonate is usually 1/100 or more, preferably 10/100 or more, more preferably 20/100 or more, still more preferably 25/100 or more, usually 10000/100 or less, preferably 500/100. Below, it is more preferably 300/100 or less, still more preferably 100/100 or less, particularly preferably 75/100 or less, and most preferably 50/100 or less. When the mass ratio is in this range, the energy device characteristics, particularly the durability characteristics, can be remarkably improved. This principle is not clear, but it is thought that by mixing at this ratio, the side reaction of the additive on the electrode can be minimized.

In case of having a LiPF ₆ in a non-aqueous electrolyte solution, the mass ratio of the total content of the unsaturated cyclic carbonate to the content of LiPF ₆ is usually 0.00005 or more, preferably 0.001 or larger, more preferably 0. It is 01 or more, more preferably 0.02 or more, particularly preferably 0.025 or more, usually 0.5 or less, preferably 0.45 or less, more preferably 0.4 or less, still more preferably 0.35 or less. When the mass ratio is in this range, the energy device characteristics, particularly the durability characteristics, can be remarkably improved. Although the principle is not clear, it is considered that the decomposition side reaction _{of LiPF 6 in the energy device system can be minimized by mixing at this ratio.}

<1-4-2. Monofluorophosphate and difluorophosphate>
The monofluorophosphate and the difluorophosphate are not particularly limited as long as they are salts having at least one monofluorophosphate or difluorophosphate structure in the molecule, respectively. In the non-aqueous electrolyte solution of the present embodiment, from diisocyanate having a cis structure represented by the above formula (1), diisocyanate having a trans structure represented by the formula (2), monofluorophosphate and difluorophosphate. By using in combination with one or more selected types, the durability characteristics can be improved in the energy device using this electrolytic solution.

The counter cations in monofluorophosphate and difluorophosphate are not particularly limited, and lithium, sodium, potassium, magnesium, calcium, NR ¹²¹ R ¹²² R ¹²³ R ¹²⁴ (in the formula, R ^{121 to} R ¹²⁴ are independent. Examples thereof include ammonium represented by a hydrogen atom or an organic group having 1 or more and 12 or less carbon atoms. The ^{organic group having 1 to 12 carbon atoms represented by R 121 to} R ¹²⁴ of the ammonium is not particularly limited, and is, for example, substituted with an alkyl group which may be substituted with a fluorine atom, a halogen atom or an alkyl group. Examples thereof include a cycloalkyl group, 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, R ^{121 to} R ¹²⁴ are independently preferably a hydrogen atom, an alkyl group, a cycloalkyl group, a nitrogen atom-containing heterocyclic group or the like. As the counter cation, lithium, sodium and potassium are preferable, and lithium is particularly preferable.

Examples of monofluorophosphate and difluorophosphate include lithium monofluorophosphate, sodium monofluorophosphate, potassium monofluorophosphate, lithium difluorophosphate, sodium difluorophosphate, potassium difluorophosphate and the like. Lithium monofluorophosphate and lithium difluorophosphate are preferable, and lithium difluorophosphate is more preferable. As the monofluorophosphate and 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 one or more fluorophosphates selected from monofluorophosphate and difluorophosphate (total amount in the case of two or more) is usually 0.001% by mass in 100% by mass of the non-aqueous electrolyte solution. % 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, particularly preferably 0.3% by mass or more, and usually 5 It is 0% by mass or less, preferably 3% by mass or less, more preferably 2% by mass or less, still more preferably 1.5% by mass or less, and particularly preferably 1% by mass or less. When the content of the fluorophosphate is within this range, the effect of improving the initial irreversible capacity is remarkably exhibited when the non-aqueous electrolyte solution is used for the energy device.

The mass ratio of one or more fluorophosphates (total amount in the case of two or more) selected from diisocyanate having a cis structure represented by the above formula (1) and monofluorophosphate and difluorophosphate is , One or more fluorophosphates selected from diisocyanate / monofluorophosphate and difluorophosphate having a cis structure represented by the formula (1) are usually 1/100 or more, preferably 10 /. 100 or more, more preferably 20/100 or more, still more preferably 25/100 or more, usually 10000/100 or less, preferably 500/100 or less, more preferably 300/100 or less, still more preferably 100/100. Hereinafter, it is particularly preferably 75/100 or less, and most preferably 50/100 or less. When the mass ratio is in this range, the energy device characteristics, particularly the durability characteristics, can be remarkably improved. This principle is not clear, but it is thought that by mixing at this ratio, the side reaction of the additive on the electrode can be minimized.

The mass ratio of one or more fluorophosphates (total amount in the case of two or more) selected from diisocyanate having a trans structure represented by the above formula (2) and monofluorophosphate and difluorophosphate is , One or more fluorophosphates selected from diisocyanate / monofluorophosphate and difluorophosphate having a trans structure represented by the formula (2) is usually 1/100 or more, preferably 10 /. 100 or more, more preferably 20/100 or more, still more preferably 25/100 or more, usually 10000/100 or less, preferably 500/100 or less, more preferably 300/100 or less, still more preferably 100/100. Hereinafter, it is particularly preferably 75/100 or less, and most preferably 50/100 or less. When the mass ratio is in this range, the energy device characteristics, particularly the durability characteristics, can be remarkably improved. This principle is not clear, but it is thought that by mixing at this ratio, the side reaction of the additive on the electrode can be minimized.

In case of having a LiPF ₆ in a non-aqueous electrolyte solution, the mass ratio of the total content of one or more fluoro phosphate selected from the monofluorophosphate and difluorophosphate salt to the content of LiPF ₆ is usually 0.00005 or more, preferably 0.001 or more, more preferably 0.01 or more, still more preferably 0.02 or more, particularly preferably 0.025 or more, usually 0.5 or less, preferably 0.45 or less, and more. It is preferably 0.4 or less, more preferably 0.35 or less. When the mass ratio is in this range, the energy device characteristics, particularly the durability characteristics, can be remarkably improved. Although the principle is not clear, it is considered that the decomposition side reaction _{of LiPF 6 in the energy device system can be minimized by mixing at this ratio.}

<1-4-3. Fluorine-containing cyclic carbonate>
The fluorine-containing cyclic carbonate is not particularly limited as long as it has a cyclic carbonate structure and contains a fluorine atom.
Examples of the fluorine-containing cyclic carbonate include a fluorinated product of a cyclic carbonate having an alkylene group having 2 or more and 6 or less carbon atoms, and a derivative thereof. For example, a fluorinated product of ethylene carbonate (hereinafter referred to as “fluorinated ethylene carbonate”). ), And derivatives thereof. Examples of the derivative of the fluorinated product of ethylene carbonate include a fluorinated product of ethylene carbonate substituted with an alkyl group (for example, an alkyl group having 1 to 4 carbon atoms). Of these, fluorinated ethylene carbonate having a fluorine number of 1 or more and 8 or less, and a derivative thereof are preferable.

Examples of the fluorinated ethylene carbonate having 1 or more and 8 or less fluorine and its derivative include monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, 4,5-difluoroethylene carbonate, 4-fluoro-4-methylethylene carbonate, 4, 5-Difluoro-4-methylethylene carbonate, 4-fluoro-5-methylethylene carbonate, 4,4-difluoro-5-methylethylene carbonate, 4- (fluoromethyl) -ethylene carbonate, 4- (difluoromethyl) -ethylene Carbonate, 4- (trifluoromethyl) -ethylene carbonate, 4- (fluoromethyl) -4-fluoroethylene carbonate, 4- (fluoromethyl) -5-fluoroethylene carbonate, 4-fluoro-4,5-dimethylethylene carbonate , 4,5-Difluoro-4,5-dimethylethylene carbonate, 4,4-difluoro-5,5-dimethylethylene carbonate and the like. Of these, monofluoroethylene carbonate, 4,4-difluoroethylene carbonate, and 4,5-difluoroethylene carbonate are preferable because they give high ionic conductivity to the electrolytic solution and easily form a stable interface protection film.

As the fluorine-containing 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 fluorine-containing cyclic carbonate (total amount in the case of two or more types) is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, still more preferably 0.01% by mass, based on 100% by mass of the non-aqueous electrolyte solution. 0.1% by mass or more, still more preferably 0.5% by mass or more, particularly preferably 1% by mass or more, most preferably 1.2% by mass or more, and preferably 10% by mass or less, more preferably. It is 7% by mass or less, more preferably 5% by mass or less, particularly preferably 3% by mass or less, and most preferably 2% by mass or less. When the fluorine-containing cyclic carbonate is used as the non-aqueous solvent, the content is preferably 1% by volume or more, more preferably 5% by volume or more, still more preferably 10% by volume or more in 100% by volume of the non-aqueous solvent. Further, it is preferably 50% by volume or less, more preferably 35% by volume or less, still more preferably 25% by volume or less.

The mass ratio of the diisocyanate having a cis structure represented by the above formula (1) to the fluorine-containing cyclic carbonate (total amount in the case of two or more types) is the diisocyanate / fluorine-containing diisocyanate having a cis structure represented by the formula (1). The cyclic carbonate is usually 1/100 or more, preferably 10/100 or more, more preferably 20/100 or more, still more preferably 25/100 or more, usually 10000/100 or less, preferably 500/100. Below, it is more preferably 300/100 or less, still more preferably 100/100 or less, particularly preferably 75/100 or less, and most preferably 50/100 or less. When the mass ratio is in this range, the energy device characteristics, particularly the durability characteristics, can be remarkably improved. This principle is not clear, but it is thought that by mixing at this ratio, the side reaction of the additive on the electrode can be minimized.

The mass ratio of the diisocyanate having a trans structure represented by the above formula (2) to the fluorine-containing cyclic carbonate (total amount in the case of two or more types) is the diisocyanate / fluorine-containing diisocyanate having a trans structure represented by the formula (2). One or more fluorophosphates selected from cyclic carbonates are usually 1/100 or more, preferably 10/100 or more, more preferably 20/100 or more, still more preferably 25/100 or more, and usually 10000. It is / 100 or less, preferably 500/100 or less, more preferably 300/100 or less, still more preferably 100/100 or less, particularly preferably 75/100 or less, and most preferably 50/100 or less. Within this mass ratio range, the energy device characteristics, particularly the durability characteristics, can be significantly improved. This principle is not clear, but it is thought that by mixing at this ratio, the side reaction of the additive on the electrode can be minimized.

In case of having a LiPF ₆ in a non-aqueous electrolyte solution, the mass ratio of the total content of the fluorine-containing cyclic carbonate to the content of LiPF ₆ is usually 0.00005 or more, preferably 0.001 or larger, more preferably 0. It is 01 or more, more preferably 0.02 or more, particularly preferably 0.025 or more, usually 0.5 or less, preferably 0.45 or less, more preferably 0.4 or less, still more preferably 0.35 or less. When the mass ratio is in this range, the energy device characteristics, particularly the durability characteristics, can be remarkably improved. Although the principle is not clear, it is considered that the decomposition side reaction _{of LiPF 6 in the energy device system can be minimized by mixing at this ratio.}

<1-4-4. Lithium imide salt>
A lithium imide salt is an anion having a structure in which two sulfonyl groups are bonded to nitrogen (-SO ₂ N ^- SO _2- ) or a structure in which two phosphoryl groups are bonded to nitrogen (-P (O) N ^- P). The salt is not particularly limited as long as it is a salt of an anion having (O)-) and a lithium cation. However, when the non-aqueous electrolyte solution of the present embodiment contains a lithium imide salt as an electrolyte, the lithium imide salt as an auxiliary agent shall not be contained in the non-aqueous electrolyte solution. In addition, those that also correspond to the fluorosulfonates described later are listed in 1-4-12. 1-4-4, not fluorosulfonate. It shall be included in the lithium imide salt.

Examples of the lithium imide salt include lithium carbonyl imide salts; lithium bis (fluorosulfonyl) imide, lithium bis (trifluoromethanesulfonyl) imide, lithium bis (pentafluoroethanesulfonyl) imide, and lithium bis (nonafluorobutanesulfonyl) imide. Lithium sulfonylimide salt; Examples thereof include lithium phosphonylimide salt such as lithium bis (difluorophosphonyl) imide. Among them, lithium bis (fluorosulfonyl) imide is more preferable because there are few side reactions at the positive electrode.

As the lithium imide 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 lithium imide salt (total amount in the case of two or more types) is usually 0.001% by mass or more, preferably 0.1% by mass or more, and more preferably 0 in 100% by mass of the non-aqueous electrolyte solution. It is 3% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, and more preferably 3% by mass or less. When the lithium imide salt content is in this range, there are few side reactions at the negative electrode.

The mass ratio of the diisocyanate having a cis structure represented by the above formula (1) to the lithium imide salt (total amount in the case of two or more types) is the diisocyanate / lithium imide salt having a cis structure represented by the formula (1). However, it is usually 1/100 or more, preferably 10/100 or more, more preferably 20/100 or more, still more preferably 25/100 or more, usually 10000/100 or less, preferably 500/100 or less. It is more preferably 300/100 or less, still more preferably 100/100 or less, particularly preferably 75/100 or less, and most preferably 50/100 or less. When the mass ratio is in this range, the energy device characteristics, particularly the durability characteristics, can be remarkably improved. This principle is not clear, but it is thought that by mixing at this ratio, the side reaction of the additive on the electrode can be minimized.

The mass ratio of the diisocyanate having the trans structure represented by the above formula (2) to the lithium imide salt (total amount in the case of two or more kinds) is the diisocyanate / lithium imide salt having the trans structure represented by the formula (2). However, it is usually 1/100 or more, preferably 10/100 or more, more preferably 20/100 or more, still more preferably 25/100 or more, usually 10000/100 or less, preferably 500/100 or less. It is more preferably 300/100 or less, still more preferably 100/100 or less, particularly preferably 75/100 or less, and most preferably 50/100 or less. When the mass ratio is in this range, the energy device characteristics, particularly the durability characteristics, can be remarkably improved. This principle is not clear, but it is thought that by mixing at this ratio, the side reaction of the additive on the electrode can be minimized.

In case of having a LiPF ₆ in a non-aqueous electrolyte solution, the mass ratio of the total content of the lithium imide salt to the content of LiPF ₆ is usually 0.00005 or more, preferably 0.001 or more, more preferably 0.01 Above, more preferably 0.02 or more, particularly preferably 0.025 or more, usually 0.5 or less, preferably 0.45 or less, more preferably 0.4 or less, still more preferably 0.35 or less. When the mass ratio is in this range, the energy device characteristics, particularly the durability characteristics, can be remarkably improved. Although the principle is not clear, it is considered that the decomposition side reaction _{of LiPF 6 in the energy device system can be minimized by mixing at this ratio.}

The non-aqueous electrolyte solution is at least selected from the group consisting of a cyclic carbonate having a carbon-carbon unsaturated bond, a fluorine-containing cyclic carbonate, a lithium imide salt, a monofluorophosphate and a difluorophosphate in addition to _{LiPF 6.} When one kind of auxiliary agent is contained, _{the mass ratio of the total content of the auxiliary agent to the content of LiPF 6} is usually 0.00005 or more, preferably 0.001 or more, more preferably 0.01 or more, and further. It is preferably 0.02 or more, particularly preferably 0.025 or more, usually 0.5 or less, preferably 0.45 or less, more preferably 0.4 or less, still more preferably 0.35 or less. When the mass ratio is in this range, the energy device characteristics, particularly the durability characteristics, can be remarkably improved. Although the principle is not clear, it is considered that the decomposition side reaction _{of LiPF 6 in the energy device system can be minimized by mixing at this ratio.}

Further, at least one auxiliary agent selected from the group in which the non-aqueous electrolyte solution consists of a cyclic carbonate having a carbon-carbon unsaturated bond, a fluorine-containing cyclic carbonate, a lithiumimide salt, a monofluorophosphate and a difluorophosphate. The total content of the auxiliary agent in 100% by mass of the non-aqueous electrolyte solution is usually 0.001% by mass or more, preferably 0.01% by mass or more, and more preferably 0.1% by mass or more. More preferably 0.3% by mass or more, particularly preferably 0.6% by mass or more, and usually 10% by mass or less, preferably 8% by mass or less, more preferably 6% by mass or less, still more preferably 5% by mass. % Or less. If the total content of the auxiliaries is within this range, side reactions in the energy device system can be efficiently suppressed.

<1-4-5. Sulfur-containing organic compounds>
The sulfur-containing organic compound is not particularly limited as long as it is an organic compound having at least one sulfur atom in the molecule.
The sulfur-containing organic compound is preferably an organic compound having an S = O group in the molecule, and is a chain sulfonic acid ester, a cyclic sulfonic acid ester, a chain sulfate ester, a cyclic sulfate ester, a chain sulfite ester, and a cyclic. Sulfonic acid ester and the like can be mentioned. Among them, a chain sulfonic acid ester, a cyclic sulfonic acid ester, a chain sulfate ester, a cyclic sulfate ester, a chain sulfite ester and a cyclic sulfite ester are preferable, and a compound having _{two S (= O) groups is more preferable.} It is preferably a chain sulfonic acid ester and a cyclic sulfonic acid ester, and particularly preferably a cyclic sulfonic acid ester. The energy device using the non-aqueous electrolyte solution of the present embodiment in which the sulfur-containing organic compound is used in combination can improve the durability characteristics.
Specific examples of the sulfur-containing organic compound include the following.

≪Chainous sulfonic acid ester≫
Fluorosulfuric acid esters such as methyl fluorosulfonate and ethyl fluorosulfonate;
Methyl methanesulfonate, ethyl methanesulfonate, 2-propinyl methanesulfonate, 3-butynyl methanesulfonate, busulfan, methyl 2- (methanesulfonyloxy) propionate, ethyl 2- (methanesulfonyloxy) propionate, 2- (Methanesulfonyloxy) 2-propynyl propionate, 3-butynyl 2- (methanesulfonyloxy) propionate, methyl methanesulfonyloxyacetate, ethyl methanesulfonyloxyacetate, 2-propynyl methanesulfonyloxyacetic acid and 3-butynyl methanesulfonyloxyacetic acid Methane sulfonic acid esters such as butynyl;
Methyl vinyl sulfonate, ethyl vinyl sulfonate, allyl vinyl sulfonate, propargyl vinyl sulfonate, methyl allyl sulfonate, ethyl allyl sulfonate, allyl allyl sulfonate, propargyl allyl sulfonate and 1,2-bis (vinyl sulfonate) ) Alkenyl sulfonic acid ester such as ethane;
Methoxycarbonylmethyl methanedisulfonic acid, ethoxycarbonylmethyl methanedisulfonic acid, 1-methoxycarbonylethyl methanedisulfonic acid, 1-ethoxycarbonylethyl methanedisulfonic acid, methoxycarbonylmethyl 1,2-ethanedisulfonic acid, 1,2-ethanedisulfonic acid Ethoxycarbonylmethyl, 1,2-ethanedisulfonic acid 1-methoxycarbonylethyl, 1,2-ethanedisulfonic acid 1-ethoxycarbonylethyl, 1,3-propanedisulfonic acid methoxycarbonylmethyl, 1,3-propanedisulfonic acid ethoxycarbonyl Methyl, 1-methoxycarbonylethyl 1,3-propanedisulfonic acid, 1-ethoxycarbonylethyl 1,3-propanedisulfonic acid, methoxycarbonylmethyl 1,3-butanedisulfonic acid, ethoxycarbonylmethyl 1,3-butanedisulfonic acid, Alkyl disulfonic acid esters such as 1,3-butanedisulfonic acid 1-methoxycarbonylethyl and 1,3-butanedisulfonic acid 1-ethoxycarbonylethyl;

≪Cyclic sulfonic acid ester≫
1,3-Propane sultone, 1-fluoro-1,3-propane sultone, 2-fluoro-1,3-propane sultone, 3-fluoro-1,3-propane sultone, 1-methyl-1,3-propane sultone , 2-Methyl-1,3-Propane Sultone, 3-Methyl-1,3-Propane Sultone, 1-Propen-1,3-Sultone, 2-Propen-1,3-Sultone, 1-Fluoro-1-Propen -1,3-sultone, 2-fluoro-1-propen-1,3-sultone, 3-fluoro-1-propen-1,3-sultone, 1-fluoro-2-propen-1,3-sultone, 2 -Fluoro-2-propen-1,3-sultone, 3-fluoro-2-propen-1,3-sultone, 1-methyl-1-propen-1,3-sultone, 2-methyl-1-propen-1 , 3-Sultone, 3-Methyl-1-propen-1,3-Sultone, 1-Methyl-2-Propen-1,3-Sultone, 2-Methyl-2-Propen-1,3-Sultone, 3-Methyl Sultone compounds such as -2-propen-1,3-sultone, 1,4-butane sultone and 1,5-pentane sultone;
Cyclic disulfonate compounds such as methylene methane disulfonate and ethylene methane disulfonate;

≪Chainous sulfate ester≫
Dialkyl sulphate compounds such as dimethyl sulphate, ethyl methyl sulphate and diethyl sulphate.

≪Cyclic sulfate ester≫
1,2-Ethylene sulphate, 1,2-propylene sulphate, 1,3-propylene sulphate, 1,2-butylene sulphate, 1,3-butylen sulphate, 1,4-butylen sulphate, 1, An alkylene sulfate compound such as 2-pentylene sulphate, 1,3-pentylene sulphate, 1,4-pentylene sulphate and 1,5-pentylene sulphate.

≪Chain sulfite ester≫
Dialkylsulfite compounds such as dimethylsulfite, ethylmethylsulfite and diethylsulfite.

≪Cyclic sulfite ester≫
1,2-Ethylene sulphite, 1,2-propylene sulphite, 1,3-propylene sulphite, 1,2-butylene sulphite, 1,3-butylen sulphite, 1,4-butylen sulphite, 1, An alkylene sulfite compound such as 2-pentylene sulphite, 1,3-pentylene sulphite, 1,4-pentylene sulphite and 1,5-pentylene sulphite.

Of these, methyl 2- (methanesulfonyloxy) propionate, ethyl 2- (methanesulfonyloxy) propionate, 2-propynyl 2- (methanesulfonyloxy) propionate, 1-methoxycarbonyl 1,3-propanedisulfonic acid Ethyl, 1-ethoxycarbonylethyl 1,3-propanedisulfonic acid, 1-methoxycarbonylethyl 1,3-butanedisulfonic acid, 1-ethoxycarbonylethyl 1,3-butanedisulfonic acid, 1,3-propanesulton, 1- Propen-1,3-sulton, 1,4-butanesulton, 1,2-ethylenesulfate, 1,2-ethylenesulfite, methyl methanesulfonate and ethyl methanesulfonate are preferable from the viewpoint of improving the initial efficiency of energy devices. , 1-methoxycarbonylethyl propanedisulfonic acid, 1-ethoxycarbonylethyl 1,3-propanedisulfonic acid, 1-methoxycarbonylethyl 1,3-butanedisulfonic acid, 1-ethoxycarbonylethyl 1,3-butanedisulfonic acid, 1 , 3-Propane sulton, 1-propen-1,3-sulton, 1,2-ethylenesulfate, 1,2-ethylenesulfite are more preferable, 1,3-propanesulton, 1-propen-1,3- Sulton is more preferred.

As the sulfur-containing organic 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 sulfur-containing organic compound (total amount in the case of two or more types) is usually 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.01% by mass or more in 100% by mass of the non-aqueous electrolyte solution. 0.1% by mass or more, particularly preferably 0.3% by mass or more, particularly preferably 0.6% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably. Is 3% by mass or less, more preferably 2% by mass or less, particularly preferably 1.5% by mass or less, and most preferably 1.0% by mass or less. When the content of the sulfur-containing organic compound is in this range, it is easy to control the output characteristics, load characteristics, low temperature characteristics, cycle characteristics, high temperature storage characteristics, etc. of the energy device.

<1-4-6. Phosphorus-containing organic compounds>
The phosphorus-containing organic compound is not particularly limited as long as it is an organic compound having at least one phosphorus atom in the molecule. The energy device using the non-aqueous electrolyte solution of the present embodiment in which the phosphorus-containing organic compound is used in combination can improve the durability characteristics.
As the phosphorus-containing organic compound, a phosphoric acid ester, a phosphonic acid ester, a phosphinic acid ester, and a phosphite ester are preferable, a phosphoric acid ester and a phosphonic acid ester are more preferable, and a phosphonic acid ester is further preferable.
Examples of the phosphorus-containing organic compound include the following.

≪Phosphate ester≫
It has vinyl groups such as dimethylvinyl phosphate, diethylvinyl phosphate, dipropylvinyl phosphate, dibutylvinyl phosphate, dipentylvinyl phosphate, methyldivinyl phosphate, ethyldivinyl phosphate, propyldivinyl phosphate, butyldivinyl phosphate, pentyldivinyl phosphate and trivinyl phosphate. Compound;

It has an allyl group such as allyldimethylphosphate, allyldiethylphosphate, allyldipropylphosphate, allyldibutylphosphate, allyldipentylphosphate, diallylmethylphosphate, diallylethylphosphate, diallylpropylphosphate, diallylbutylphosphate, diallylpentylphosphate and triallylphosphate. Compound;

Propargyl dimethyl phosphate, propargyl diethyl phosphate, propargyl dipropyl phosphate, propargyl dibutyl phosphate, propargyl dipentyl phosphate, dipropargyl methyl phosphate, dipropargyl ethyl phosphate, dipropargyl propyl phosphate, dipropargyl butyl phosphate, dipropargyl pentyl phosphate, etc. Compound having a propargyl group;

2-Acryloyloxymethyldimethylphosphate, 2-acryloyloxymethyldiethyl phosphate, 2-acryloyloxymethyldipropylphosphate, 2-acryloyloxymethyldibutylphosphate, 2-acryloyloxymethyldipentylphosphate, bis (2-acryloyloxymethyl) methyl Phosphate, bis (2-acryloyloxymethyl) ethyl phosphate, bis (2-acryloyloxymethyl) propyl phosphate, bis (2-acryloyloxymethyl) butyl phosphate, bis (2-acryloyloxymethyl) pentyl phosphate and tris (2-) Acryloyloxymethyl) A compound having a 2-acryloyloxymethyl group of phosphate;

2-Acryloyloxyethyl dimethyl phosphate, 2-acryloyloxyethyl diethyl phosphate, 2-acryloyloxyethyl dipropyl phosphate, 2-acryloyloxyethyl dibutyl phosphate, 2-acryloyloxyethyl dipentyl phosphate, bis (2-acryloyloxyethyl) methyl Phosphate, bis (2-acryloyloxyethyl) ethyl phosphate, bis (2-acryloyloxyethyl) propyl phosphate, bis (2-acryloyloxyethyl) butyl phosphate and bis (2-acryloyloxyethyl) pentyl phosphate and tris (2-) Acryloyloxyethyl) phosphate

≪Phosphonate ester≫
Trimethylphosphonoformate, methyldiethylphosphonoformate, methyldipropylphosphonoformate, methyldibutylphosphonoformate, triethylphosphonoformate, ethyl dimethylphosphonoformate, ethyldipropylphosphonoformate, ethyl Dibutylphosphonoformate, tripropylphosphonoformate, propyl dimethylphosphonoformate, propyl diethylphosphonoformate, propyldibutylphosphonoformate, tributylphosphonoformate, butyl dimethylphosphonoformate, butyl diethylphospho Noformate, butyl dipropylphosphonoformate, methyl bis (2,2,2-trifluoroethyl) phosphonoformate, ethyl bis (2,2,2-trifluoroethyl) phosphonoformate, propyl bis (2,2,2-trifluoroethyl) phosphonoformate, butyl bis (2,2,2-trifluoroethyl) phosphonoformate, trimethylphosphonoacetate, methyldiethylphosphonoacetate, methyldipropylphosphono Acetate, methyldibutylphosphonoacetate, triethylphosphonoacetate, ethyl dimethylphosphonoacetate, ethyldipropylphosphonoacetate, ethyldibutylphosphonoacetate, tripropylphosphonoacetate, propyldimethylphosphonoacetate, propyldiethylphosphonoacetate, Propyldibutylphosphonoacetate, tributylphosphonoacetate, butyldimethylphosphonoacetate, butyldiethylphosphonoacetate, butyldipropylphosphonoacetate, methylbis (2,2,2-trifluoroethyl) phosphonoacetate, ethylbis ( 2,2,2-trifluoroethyl) phosphonoacetate, propyl bis (2,2,2-trifluoroethyl) phosphonoacetate, butyl bis (2,2,2-trifluoroethyl) phosphonoacetate, allyldimethyl Phosphonoacetate, allyl diethylphosphonoacetate, 2-propynyl dimethylphosphonoacetate, 2-propynyl diethylphosphonoacetate, trimethyl 3-phosphonopropionate, methyl 3- (diethylphosphono) propionate, methyl 3- (di) Propylphosphono) Propylonate, methyl 3- (dibutylphosphono) propionate, triethyl 3-phosphonopropionate, ethyl 3- (dimethylphosphono) propionate, ethyl 3- (dipropylphosphono) propionate, ethyl 3- (dibutylphosphono) Propylonate, Tripropyl 3-phosphonopropionate, Propyl 3- (dimethylphosphono) propionate, Propyl 3- (diethylphosphono) propionate, Propyl 3- (dibutylphosphono) propionate, Tributyl 3-phosphonopropionate , Butyl 3- (dimethylphosphono) propionate, butyl 3- (diethylphosphono) propionate, butyl 3- (dipropylphosphono) propionate, methyl 3- (bis (2,2,2-trifluoroethyl) phosphono) Propionate, ethyl 3- (bis (2,2,2-trifluoroethyl) phosphono) propionate, propyl 3- (bis (2,2,2-trifluoroethyl) phosphono) propionate, butyl 3-(bis (2,2,2-trifluoroethyl) phosphono) 2,2-Trifluoroethyl) phosphono) propionate, trimethyl 4-phosphonobutylate, methyl 4- (diethylphosphono) butyrate, methyl 4- (dipropylphosphono) butyrate, methyl 4- (dibutylphosphono) butyrate , Triethyl 4-phosphonobutylate, ethyl 4- (dimethylphosphono) butyrate, ethyl 4- (dipropylphosphono) butyrate, ethyl 4- (dibutylphosphono) butyrate, tripropyl 4-phosphonobutylate, propyl 4- (Dimethylphosphono) butyrate, propyl 4- (diethylphosphono) butyrate, propyl 4- (dibutylphosphono) butyrate, tributyl 4-phosphonobutylate, butyl 4- (dimethylphosphono) butyrate, butyl 4- (Diethylphosphono) butyrate, butyl 4- (dipropylphosphono) butyrate, etc.

Of these, from the viewpoint of improving energy device characteristics, triallyl phosphate and tris (2-acryloyloxyethyl) phosphate, trimethylphosphonoacetate, triethylphosphonoacetate, 2-propynyldimethylphosphonoacetate, 2-propynyldiethylphosphonoacetate. Acetate is preferred.
As the phosphorus-containing organic 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 phosphorus-containing organic compound (total amount in the case of two or more kinds) is usually 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.01% by mass or more in 100% by mass of the non-aqueous electrolyte solution. 0.1% by mass or more, more preferably 0.4% by mass or more, particularly preferably 0.6% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably 3 It is mass% or less, more preferably 2 mass% or less, particularly preferably 1.2 mass% or less, and most preferably 0.9 mass% or less. When the content of the phosphorus-containing organic compound is within this range, it is easy to control the output characteristics, load characteristics, low temperature characteristics, cycle characteristics, high temperature storage characteristics, etc. of the energy device.

<1-4-7. Organic compounds with cyano groups>
The organic compound having a cyano group is not particularly limited as long as it is an organic compound having a cyano group having at least one cyano group in the molecule. Of these, an organic compound having a cyano group having two or three cyano groups is preferable. The energy device using the non-aqueous electrolyte solution of the present embodiment containing an organic compound having a cyano group can improve durability characteristics.
Specific examples of the organic compound having a cyano group include the following.

<< Compound with one cyano group >>
Propionitrile, butyronitrile, pentanenitrile, hexanenitrile, heptanenitrile, octanenitrile, perargononitrile, decanenitrile, undecanenitrile, dodecanenitrile, cyclopentanecarbonitrile, cyclohexanecarbonitrile, acrylonitrile, methacrylonitrile, crotononitrile 3-Methylcrotononitrile, 2-methyl-2-butennitril, 2-pentenenitrile, 2-methyl-2-pentenenitrile, 3-methyl-2-pentenenitrile and 2-hexenenitrile;

≪Compound with two cyano groups≫
Marononitrile, succinonitrile, glutaronitrile, adiponitrile, pimeronitrile, suberonitrile, azelanitrile, sebaconitrile, undecandinitrile, dodecandinitrile, methylmalononitrile, ethylmalononitrile, isopropylmalononitrile, tert-butylmalononitrile, methylsuccinonitrile , 2,2-Dimethylsuccinonitrile, 2,3-dimethylsuccinonitrile, 2,3,3-trimethylsuccinonitrile, 2,2,3,3-tetramethylsuccinonitrile, 2,3-diethyl- 2,3-Dimethylsuccinonitrile, 2,2-diethyl-3,3-dimethylsuccinonitrile, bicyclohexyl-1,1-dicarbonitrile, bicyclohexyl-2,2-dicarbonitrile, bicyclohexyl-3 , 3-Dicarbonitrile, 2,5-dimethyl-2,5-
Hexadicarbonitrile, 2,3-diisobutyl-2,3-dimethylsuccinonitrile, 2,2-diisobutyl-3,3-dimethylsuccinonitrile, 2-methylglutaronitrile, 2,3-dimethylglutaronitrile , 2,4-Dimethylglutaronitrile, 2,2,3,3-tetramethylglutaronitrile, 2,2,4,4-tetramethylglutaronitrile, 2,2,3,4-tetramethylglutaronitrile Nitrile, 2,3,3,4-tetramethylglutaronitrile, maleonitrile, fumaronitrile, 1,4-dicyanopentane, 2,6-dicyanoheptan, 2,7-dicyanooctane, 2,8-dicyanononane, 1,6 -Dicyanodecane, 1,2-didianobenzene, 1,3-dicyanobenzene, 1,4-dicyanobenzene, 3,3'-(ethylenedioxy) dipropionitrile, 3,3'-(ethylenedithio) dipro Pionitrile and 3,9-bis (2-cyanoethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane;

≪Compound with 3 cyano groups≫
Tris (2-cyanoethyl) amine, 1,2,3-propanetricarbonitol, 1,2,3-butanetricarbonitol, 1,2,3-pentanetricarbonitol, 1,3,4-pentanetricarbo Nittle, 1,3,5-pentane tricarbonitol, 1,3,6-pentane tricarbonitol;

Of these, malononitrile, succinonitrile, glutaronitrile, adiponitrile, pimeronitrile, suberonitrile, azelanitrile, sebaconitrile, undecanenitrile, dodecanenitrile and 3,9-bis (2-cyanoethyl) -2,4,8,10 -Tetraoxaspiro [5,5] undecane, fumaronitrile, and 1,3,5-pentanetricarbonitol are preferable from the viewpoint of improving the high temperature storage durability characteristics of the energy device. In addition, succinonitrile, glutaronitrile, adiponitrile, pimeronitrile, suberonitrile, glutaronitrile, 3,9-bis (2-cyanoethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane and 1 , 3,5-Pentane tricarbonitol is more preferable because it has a particularly excellent effect of improving the high temperature storage durability characteristics of the energy device and is less deteriorated by a side reaction at the electrode.

As the organic compound having a cyano group, 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 organic compound having a cyano group (total amount in the case of two or more kinds) is usually 0.001% by mass or more, preferably 0.01% by mass or more, based on 100% by mass of the non-aqueous electrolyte solution. It is preferably 0.1% by mass or more, more preferably 0.4% by mass or more, particularly preferably 0.6% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, more preferably. Is 3% by mass or less, more preferably 2% by mass or less, particularly preferably 1.2% by mass or less, and most preferably 0.9% by mass or less. When the content of the organic compound having a cyano group is within this range, it is easy to control the output characteristics, load characteristics, low temperature characteristics, cycle characteristics, high temperature storage characteristics, etc. of the energy device.

<1-4-8. Organic compounds having isocyanate groups other than the compounds represented by the formulas (1) and (2)>
The organic compound having an isocyanate group other than the compounds represented by the formulas (1) and (2) is not particularly limited as long as it is an organic compound having at least one isocyanate group in the molecule, but the number of isocyanate groups is not particularly limited. Is preferably 1 or more and 4 or less, more preferably 2 or more and 3 or less, and further preferably 2 in one molecule. By containing an organic compound having an isocyanate group other than the compounds represented by the formulas (1) and (2) in the non-aqueous electrolyte solution of the present embodiment, the durability characteristics of the energy device can be improved.

Examples of the organic compound having an isocyanate group other than the compounds represented by the formulas (1) and (2) include the following.
Isocyanate groups such as methyl isocyanate, ethyl isocyanate, propyl isocyanate, isopropyl isocyanate, butyl isocyanate, tarsal butyl isocyanate, pentyl isocyanate hexyl isocyanate, cyclohexyl isocyanate, vinyl isocyanate, allyl isocyanate, ethynyl isocyanate, propargyl isocyanate, phenyl isocyanate, fluorophenyl isocyanate, etc. Organic compound having one;

Monomethylene diisocyanate, dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, 1,3-diisocyanate Natopropane, 1,4-diisocyanato-2-butene, 1,4-diisocyanato-2-fluorobutane, 1,4-diisocyanato-2,3-difluorobutane, 1,5-diisocyanato-2-pentene, 1,5 -Diisocyanato-2-methylpentane, 1,6-diisocyanato-2-hexene, 1,6-diisocyanato-3-hexene, 1,6-diisocyanato-3-fluorohexane, 1,6-diisocyanato-3,4-difluoro Hexane, toluenediisocyanate, xylene diisocyanate, tolylene diisocyanate, 1,2-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl) cyclohexane, 1,2-diisocyanatocyclohexane, 1,3-di Isocyanatocyclohexane, 1,4-diisocyanatocyclohexane, dicyclohexylmethane-1,1'-diisocyanate, dicyclohexylmethane-2,2'-diisocyanate, dicyclohexylmethane-3,3'-diisocyanate, dicyclohexylmethane-4,4' -Diisocyanate, bicyclo [2.2.1] heptane-2,5-diylbis (methylisocyanate), bicyclo [2.2.1] heptane-2,6-diylbis (methylisocyanate), isophorone diisocyanate, carbonyl diisocyanate, 1,4-Diisocyanatobutane-1,4-dione, 1,5-diisocyanatopentane-1,5-dione, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethyl Organic compounds having two isocyanate groups, such as hexamethylene diisocyanate; and the like.

Of these, monomethylene diisocyanate, dimethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, nonamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, dicyclohexylmethane -4,4'-diisocyanate, bicyclo [2.2.1] heptane-2,5-diylbis (methylisocyanate), bicyclo [2.2.1] heptane-2,6-diylbis (methylisocyanate), diisocyanate Organic compounds having two isocyanate groups, such as isophorone, 2,2,4-trimethylhexamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate, are preferable from the viewpoint of improving storage characteristics. Dicyclohexylmethane-4,4'-diisocyanate, bicyclo [2.2.1] heptane-2,5-diylbis (methylisocyanate), bicyclo [2.2.1] heptane-2,6-diylbis (methylisocyanate), Isophorone diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate are more preferable, dicyclohexylmethane-4,4'-diisocyanate, bicyclo [2.2.1]. ] Heptane-2,5-diylbis (methylisocyanate), bicyclo [2.2.1] heptane-2,6-diylbis (methylisocyanate) are more preferable.

The organic compound having an isocyanate group other than the compounds represented by the formulas (1) and (2) is a trimeric compound derived from a compound having at least two isocyanate groups in the molecule, or a polyhydric alcohol thereof. It may be an aliphatic polyisocyanate to which is added. For example, biuret, isocyanurate, adduct and bifunctional type modified polyisocyanate represented by the basic structures of the following formulas (2-6-1) to (2-6-4) can be mentioned.

In formulas (2-6-1) to (2-6-4), R and R'are independently arbitrary divalent or trivalent hydrocarbon groups (for example, tetramethylene group and hexamethylene group). ).
Organic compounds having at least two isocyanate groups in the molecule also include so-called blocked isocyanate, which is blocked with a blocking agent to improve storage stability. Examples of the blocking agent include alcohols, phenols, organic amines, oximes, and lactams. Specifically, n-butanol, phenol, tributylamine, diethylethanolamine, methylethylketoxim, and ε-caprolactam. And so on.

For the purpose of promoting reactions based on organic compounds having isocyanate groups other than the compounds represented by the formulas (1) and (2) and obtaining higher effects, metal catalysts such as dibutyltin dilaurate and 1,8 It is also preferable to use an amine-based catalyst such as −diazabicyclo [5.4.0] undecene-7 in combination.
As the organic compound having an isocyanate group other than the compounds represented by the formulas (1) and (2), 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 organic compound having an isocyanate group other than the compounds represented by the formulas (1) and (2) (total amount in the case of two or more kinds) is 0.001% by mass in 100% by mass of the non-aqueous electrolyte solution. % Or more, preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and 10% by mass or less, preferably 5% by mass or less, more preferably. Is 3% by mass or less. If the content of the organic compound having an isocyanate group other than the compounds represented by the formulas (1) and (2) is within this range, the output characteristics, load characteristics, low temperature characteristics, cycle characteristics, and high temperature storage characteristics of the energy device Etc. are easy to control.

<1-4-9. Silicon-containing compounds>
The non-aqueous electrolyte solution according to the present embodiment may contain a silicon-containing compound (hereinafter, may be simply referred to as “silicon-containing compound”). The silicon-containing compound is not particularly limited as long as it is a compound having at least one silicon atom in the molecule. By including the silicon-containing compound in the non-aqueous electrolyte solution, the durability characteristics of the energy device can be improved.

Examples of the silicon-containing compound include the following compounds.
Tris borate (trimethylsilyl), tris borate (trimethoxysilyl), tris borate (triethylsilyl), tris borate (triethoxysilyl), tris borate (dimethylvinylsilyl) and tris borate (diethylvinylsilyl) Boric acid compounds such as;
Tris (trimethylsilyl) phosphate, Tris (triethylsilyl) phosphate, Tris (tripropylsilyl) phosphate, Tris (triphenylsilyl) phosphate, Tris (trimethoxysilyl) phosphate, Tris (triethoxysilyl) phosphate , Phosphoric acid compounds such as tris phosphate (triphenoxysilyl), tris phosphate (dimethylvinylsilyl) and trisphosphate (diethylvinylsilyl);

Tris phosphite (trimethylsilyl), Tris phosphite (triethylsilyl), Tris phosphite (tripropylsilyl), Tris phosphite (triphenylsilyl), Tris phosphite (trimethoxysilyl), phosphorous acid Phosphorous acid compounds such as tris (triethoxysilyl), tris phosphite (triphenoxysilyl), tris phosphite (dimethylvinylsilyl) and tris phosphite (diethylvinylsilyl);
Sulfonic acid compounds such as trimethylsilyl methanesulfonic acid and trimethylsilyl tetrafluoromethanesulfonate;
Hexamethyldisilane, hexaethyldisilane, 1,1,2,2-tetramethyldisilane, 1,1,2,2-tetraethyldisilane, 1,2-diphenyltetramethyldisilane and 1,1,2,2-tetraphenyl Disilane compounds such as disilane;
And so on.

Of these, tris borate (trimethylsilyl), tris phosphate (trimethylsilyl), tris phosphite (trimethylsilyl), trimethylsilyl methanesulfonate, trimethylsilyl tetrafluoromethanesulfonate, hexamethyldisilane, hexaethyldisilane, 1,2- Diphenyltetramethyldisilane and 1,1,2,2-tetraphenyldisilane are preferred, with tris borate (trimethylsilyl), tris phosphate (trimethylsilyl), tris phosphite (trimethylsilyl) and hexamethyldisilane being more preferred.

As the silicon-containing 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 silicon-containing compound (total amount in the case of two or more types) is usually 0.001% by mass or more, preferably 0.1% by mass or more, and more preferably 0 in 100% by mass of the non-aqueous electrolyte solution. It is 3% by mass or more, and usually 10% by mass or less, preferably 5% by mass or less, and more preferably 3% by mass or less. When the content of the silicon-containing compound is within this range, it is easy to control the output characteristics, load characteristics, low temperature characteristics, cycle characteristics, high temperature storage characteristics, etc. of the energy device.

<1-4-10. Borate>
In the present embodiment, the borate is not particularly limited as long as it is a salt having at least one boron atom in the molecule. However, those corresponding to oxalate are 1-4-10. Not borate, but 1-4-11. It shall be included in oxalate. In the non-aqueous electrolyte solution of the present embodiment, by using the compound represented by the formula (1) or the formula (2) in combination with a borate, the durability characteristics of the energy device using this electrolyte solution are improved. Can be done.

Examples of the counter cation in the borate include lithium, sodium, potassium, magnesium, calcium, rubidium, cesium, barium and the like, and lithium is preferable.
As the borate, a lithium salt is preferable, and a lithium borate-containing salt can also be preferably used. For example, LiBF ₄ , LiBF ₃ CF ₃ , LiBF ₃ C ₂ F ₅ , LiBF ₃ C ₃ F ₇ , LiBF ₂ (CF ₃ ) ₂ , LiBF ₂ (C ₂ F ₅ ) ₂ , LiBF ₂ (CF ₃ SO ₂ ) ₂ , LiBF2 (C ₂ F ₅ SO ₂ ) _{2 and the} like. Above all, LiBF ₄ is more preferable because it has an effect of improving the initial charge / discharge efficiency and high temperature cycle characteristics of the energy device. As the borate, one type may be used alone, or two or more types may be used in combination in any combination and ratio.

The content of borate (total amount in the case of two or more kinds) is usually 0.05% by mass or more, preferably 0.1% by mass or more, and more preferably 0 in 100% by mass of the non-aqueous electrolyte solution. .2% by mass or more, more preferably 0.3% by mass or more, particularly preferably 0.4% by mass or more, and usually 10.0% by mass or less, preferably 5.0% by mass or less. It is preferably 3.0% by mass or less, more preferably 2.0% by mass or less, and particularly preferably 1.0% by mass or less. When the borate content is within this range, the side reaction of the negative electrode of the energy device is suppressed and it is difficult to increase the resistance.

<1-4-11. Oxalate>
In the present embodiment, the oxalate is not particularly limited as long as it is a compound having at least one oxalic acid structure in the molecule. In the non-aqueous electrolyte solution of the present embodiment, by using the compound represented by the formula (1) or the formula (2) in combination with oxalate, the durability characteristics of the energy device using this electrolyte solution are improved. Can be done.
As the oxalate, a metal salt represented by the following formula (9) is preferable. This salt is a salt having an oxalate complex as an anion.

(In the formula, M ¹ is an element selected from the group consisting of Group 1, Group 2 and aluminum (Al) ^{in the periodic table, and M 2} is from the transition metal, Group 13, Group 14, and Group 15 of the periodic table. ^{R 91} is an element selected from the group consisting of halogen, an alkyl group having 1 to 11 carbon atoms and a halogen-substituted alkyl group having 1 to 11 carbon atoms, and a and b are groups. It is a positive integer, c is 0 or a positive integer, and d is an integer 1-3.)
M ¹ is preferably lithium, sodium, potassium, magnesium, or calcium, and lithium is particularly preferable, from the viewpoint of energy device characteristics when the non-aqueous electrolyte solution of the present embodiment is used for an energy device such as a lithium secondary battery.

M ² is particularly preferably boron and phosphorus in terms of electrochemical stability when used in lithium-based energy devices such as lithium secondary batteries and lithium ion capacitors.
^Examples of R 91 include fluorine, chlorine, methyl group, trifluoromethyl group, ethyl group, pentafluoroethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group and the like. A trifluoromethyl group is preferred.

Examples of the metal salt represented by the formula (9) include the following.
Lithium oxalate borate salts such as lithium difluorooxalate borate and lithium bis (oxalate) borate;
Lithium oxalate phosphate salts such as lithium tetrafluorooxalat phosphate, lithium difluorobis (oxalate) oxalate, lithium tris (oxalate) oxalate;
Of these, lithium bis (oxalate) borate and lithium difluorobis (oxalate) phosphate are preferable, and lithium bis (oxalate) borate is more preferable.

As the oxalate, one type may be used alone, or two or more types may be used in combination in any combination and ratio.
The content of oxalate (total amount in the case of two or more kinds) is usually 0.001% by mass or more, preferably 0.01% by mass or more, and more preferably 0 in 100% by mass of the non-aqueous electrolyte solution. .1% by mass or more, particularly preferably 0.3% 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. , Particularly preferably 1% by mass or less. When the oxalate content is in this range, it is easy to control the output characteristics, load characteristics, low temperature characteristics, cycle characteristics, high temperature storage characteristics, etc. of the energy device.

<1-4-12. Fluorosulfate>
The fluorosulfonate in the present embodiment is not particularly limited as long as it is a salt having at least one fluorosulfonic acid structure in the molecule. By using the compound represented by the above formula (1) or (2) in combination with the fluorosulfonate in the non-aqueous electrolyte solution of the present embodiment, the durability characteristics are improved in the energy device using this electrolyte solution. can do.

The counter cations in the fluorosulfonate are not particularly limited, and lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, barium, and NR ¹³¹ R ¹³² R ¹³³ R ¹³⁴ (in the formula, R ^{131 to} R ¹³⁴ are Independently, ammonium represented by a hydrogen atom or an organic group having 1 to 12 carbon atoms) can be mentioned. The ^{organic group having 1 to 12 carbon atoms represented by R 131 to} R ¹³⁴ of the ammonium is not particularly limited, and is, for example, substituted with an alkyl group which may be substituted with a fluorine atom, a halogen atom or an alkyl group. Examples thereof include a cycloalkyl group, 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, R ^{131 to} R ¹³⁴ are independently preferably a hydrogen atom, an alkyl group, a cycloalkyl group, a nitrogen atom-containing heterocyclic group or the like. As the counter cation, lithium, sodium and potassium are preferable, and lithium is particularly preferable.

Examples of the fluorosulfonate include lithium fluorosulfonate, sodium fluorosulfonate, potassium fluorosulfonate, rubidium fluorosulfonate, cesium fluorosulfonate, and the like, and lithium fluorosulfonate is preferable. An imide salt having a fluorosulfonic acid structure such as lithium bis (fluorosulfonyl) imide can also be used as the fluorosulfonate.

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 (total amount in the case of two or more kinds) is usually 0.05% by mass or more, preferably 0.1% by mass or more, more preferably 0.1% by mass or more in 100% by mass of the non-aqueous electrolyte solution. 0.2% by mass or more, more preferably 0.3% by mass or more, particularly preferably 0.4% by mass or more, and usually 10% by mass or less, preferably 8% by mass or less, more preferably 5 It is mass% or less, more preferably 2 mass% or less, and particularly preferably 1 mass% or less. When the content of the fluorosulfonate is within this range, side reactions in the energy device are unlikely to occur and resistance is unlikely to increase.

<1-4-13. Other auxiliaries>
Other known auxiliaries can be used in the non-aqueous electrolyte solution according to the embodiment of the present invention. Other auxiliaries include
Carbonate compounds such as erythritan carbonate, spiro-bis-dimethylene carbonate, methoxyethyl-methyl carbonate;
Biphenyl, alkylbiphenyl, terphenyl, partially hydride of terphenyl, cyclohexylbenzene, t-butylbenzene, t-amylbenzene, diphenyl ether, dibenzofuran, diphenylcyclohexane, 1,1,3-trimethyl-3-phenylindane, etc. Aromatic compounds;
Partially fluorinated compounds of the above aromatic compounds such as 2-fluorobiphenyl, o-cyclohexylfluorobenzene, p-cyclohexylfluorobenzene;
Fluorine-containing anisole compounds such as 2,4-difluoroanisole, 2,5-difluoroanisole, 2,6-difluoroanisole, and 3,5-difluoroanisole;
Aromatic acetates such as 3-propylphenylacetate, 2-ethylphenylacetate, benzylphenylacetate, methylphenylacetate, benzylacetate, phenethylphenylacetate;
Aromatic carbonates such as diphenyl carbonate and methylphenyl carbonate;
Succinic anhydride, glutaric anhydride, maleic anhydride, citraconic anhydride, glutaconic anhydride, itaconic anhydride, diglycolic anhydride, cyclohexanedicarboxylic acid anhydride, cyclopentanetetracarboxylic acid dianhydride, phenylsuccinic anhydride, etc. Carbonic Acid Anhydride;
Spiro compounds such as 3,9-divinyl-2,4,8,10-tetraoxaspiro [5.5] undecane;
Sulfur-containing compounds such as N, N-dimethylmethanesulfonamide and N, N-diethylmethanesulfonamide;
Phosphorus-containing trimethyl phosphite, triethyl phosphite, triphenyl phosphite, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, methyl dimethylphosphine oxide, ethyl diethylphosphine oxide, trimethylphosphine oxide, triethylphosphine oxide, etc. Compound;
Nitrogen-containing compounds such as 1-methyl-2-pyrrolidinone, 1-methyl-2-piperidone, 3-methyl-2-oxazolidinone, 1,3-dimethyl-2-imidazolidinone and N-methylsuccinimide;
Hydrocarbon compounds such as heptane, octane, nonane, decane, cycloheptane;

Pentafluorophenyl methanesulfonate, pentafluorophenyl trifluoromethanesulfonate, pentafluorophenyl acetate, pentafluoroacetate pentafluorophenyl, methyl pentafluorophenyl carbonate, lithium ethyl methyloxycarbonylphosphonate, lithium ethyl ethyloxycarbonylphosphonate, lithium ethyl 2-propynyl Oxycarbonylphosphonate, lithium ethyl 1-methyl-2-propynyloxycarbonylphosphonate, lithium ethyl 1,1-dimethyl-2-propynyloxycarbonylphosphonate, lithium methyl sulphate, lithium ethyl sulphate, lithium 2-propynyl sulphate, lithium 1-methyl -2-Propinyl sulphate, lithium 1,1-dimethyl-2-propynyl sulphate, lithium 2,2,2-trifluoroethyl sulphate, methyl trimethylsilyl sulphate, ethyl trimethylsilyl sulphate, 2-propynyl trimethylsilyl sulphate, dilithium ethylene disulfate, 2- Butin-1,4-diyl dimethanesulfonate, 2-butin-1,4-diyldiethanesulfonate, 2-butin-1,4-diyldiformate, 2-butin-1,4-diyldiacetate, 2-butin -1,4-diyl dipropionate, 4-hexadiyne-1,6-diyl dimethanesulfonate, 2-propynyl methanesulfonate, 1-methyl-2-propynyl methanesulfonate, 1,1-dimethyl-2-propynyl methanesulfonate, 2 -Propinyl ethane sulfonate, 2-propynyl vinyl sulfonate, methyl 2-propynyl carbonate, ethyl 2-propynyl carbonate, bis (2-propynyl) carbonate, methyl 2-propynyl oxalate, ethyl 2-propynyl oxalate, bis (2-propynyl) oxalate , 2-Propinyl acetate, 2-Propinyl formate, 2-Propinyl methacrylate, Di (2-Propinyl) glutarate, 2,2-Dioxide-1,2-oxathiolan-4-yl acetate, 2,2-Dioxide-1,2 -Oxatiolan-4-yl propionate, 5-methyl-1,2-oxathiolan-4-one 2,2 -Dioxide, 5,5-dimethyl-1,2-oxathiolane-4-one 2,2-dioxide, 2-isocyanatoethyl acrylate, 2-isocyanatoethyl methacrylate, 2-isocyanatoethyl crotonate, 2- (2- (2-) Isocyanatoethoxy) ethyl acrylate, 2- (2-isocyanatoethoxy) ethyl methacrylate, 2- (2-isocyanatoethoxy) ethyl crotonate, 2-allyl anhydride succinic acid, 2- (1-pentene-3-yl) anhydrous Succinic acid, 2- (1-hexene-3-yl) anhydrous succinic acid, 2- (1-heptene-3-yl) sulphate anhydride, 2- (1-octene-3-yl) sulphate anhydride, 2- (1-Nonene-3-yl) Isocyanate, 2- (3-Buten-2-yl) Isocyanate, 2- (2-Methylallyl) Isocyanate, 2- (3-Methyl-3-butene- 2-Il) Isocyanate succinic acid; and the like.

These may be used alone or in combination of two or more. By adding these auxiliaries, the capacity retention characteristics and cycle characteristics of the energy device after high temperature storage can be improved.

The content of other auxiliaries is not particularly limited and is arbitrary as long as the effects of the present invention are not significantly impaired. The other auxiliary agent is preferably 0.01% by mass or more and 5% by mass or less in 100% by mass of the non-aqueous electrolyte solution. When the content of the other auxiliary agent is within this range, the effect of the other auxiliary agent is likely to be sufficiently exhibited, and it is easy to avoid a situation in which the characteristics of the energy device such as the high load discharge characteristic are deteriorated. The content of the other auxiliary agent is more preferably 0.1% by mass or more, further preferably 0.2% by mass or more, still more preferably 3% by mass or less, still more preferably 1% by mass or less. ..

<1-5. Manufacturing method of non-aqueous electrolyte solution>
The non-aqueous electrolyte solution can be prepared by dissolving an electrolyte, a specific diisocyanate compound, and, if necessary, the above-mentioned "auxiliary agent" in the above-mentioned non-aqueous solvent.

When preparing the non-aqueous electrolyte solution, each raw material of the non-aqueous electrolyte solution, that is, an electrolyte such as a lithium salt, a specific silane, a non-aqueous solvent, a compound represented by the formulas (1) and (2), and other additions are added. It is preferable that the agent and the like are dehydrated in advance. As for the degree of dehydration, it is desirable to dehydrate until it is usually 50 mass ppm or less, preferably 30 mass ppm or less.

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

<2. Energy device using non-aqueous electrolyte solution>
An energy device using a non-aqueous electrolyte solution includes a plurality of electrodes capable of storing or releasing metal ions, and the non-aqueous electrolyte solution described above. Specific examples of the types of energy devices include metal ion capacitors such as primary batteries, secondary batteries, and lithium ion capacitors. Among them, a primary battery or a secondary battery is preferable, and a secondary battery is particularly preferable. It is also preferable that the non-aqueous electrolyte solution used for these energy devices is a so-called gel electrolyte that is pseudo-solidified with a polymer, a filler, or the like. Hereinafter, the energy device will be described.

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

<2-1-2. Non-aqueous electrolyte solution>
As the non-aqueous electrolyte solution, the above-mentioned non-aqueous electrolyte solution is used. It is also possible to mix and use another non-aqueous electrolyte solution with the non-aqueous electrolyte solution as long as the gist of the invention according to the present embodiment is not deviated.

<2-1-3. Negative electrode ＞
The negative electrode active material used for the negative electrode is not particularly limited as long as it can electrochemically occlude and release metal ions. Specific examples thereof include carbonaceous materials, metal compound materials, lithium-containing metal composite oxide materials, and the like. One of these may be used alone, or two or more thereof may be arbitrarily combined and used in combination.
Of these, carbonaceous materials and metal compound materials are preferable. Among the metal compound-based materials, a material containing silicon is preferable, and therefore, as the negative electrode active material, a carbonaceous material and a material containing silicon are particularly preferable.
It is also preferable to use the same negative electrode as in the first embodiment.

<2-1-3-1. Carbon material>
The carbonaceous material used as the negative electrode active material is not particularly limited, but the one selected from the following (a) to (d) provides a secondary battery having a good balance of initial irreversible capacity and high current density charge / discharge characteristics. Therefore, it is preferable.
(A) Natural graphite (B) Carbonaceous material obtained by heat-treating artificial carbonaceous material and artificial graphite material at least once in the range of 400 ° C to 3200 ° C (c) At least two types of negative electrode active material layers Consisting of carbonaceous chondrites with different crystallinity,
And / or a carbonaceous material having an interface in which different crystalline carbonaceous materials are in contact with each other (d) The negative electrode active material layer is composed of at least two kinds of carbonaceous materials having different orientations and / or different orientations thereof. Carbon material having an interface in contact with the carbon materials of (a) to (d) One type of carbon material may be used alone, or two or more types may be used in any combination and ratio. Good.

Specific examples of the artificial carbonaceous material or the artificial graphite material in (a) above include natural graphite, coal-based coke, petroleum-based coke, coal-based pitch, petroleum-based pitch, and those obtained by oxidizing these pitches;
Needle coke, pitch coke and partially graphitized carbon material;
Thermal decomposition products of organic substances such as furnace black, acetylene black, and pitch-based carbon fibers;
Carbideable organics and their carbides; and
Examples thereof include solution-like carbides in which a carbonizable organic substance is dissolved in a low-molecular-weight organic solvent such as benzene, toluene, xylene, quinoline, and n-hexane.

In addition, all of the above carbonaceous materials (a) to (d) are conventionally known, their manufacturing methods are well known to those skilled in the art, and these commercially available products can also be purchased.

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

<2-1-3-3. Lithium-containing metal composite oxide material>
The lithium-containing metal composite oxide material used as the negative electrode active material is not particularly limited as long as it can store and release lithium, but a lithium-containing composite metal oxide material containing titanium is preferable, and composite oxidation of lithium and titanium is preferable. A substance (hereinafter, may be abbreviated as "lithium-titanium composite oxide") is particularly preferable. That is, it is particularly preferable to use a lithium titanium composite oxide having a spinel structure in a negative electrode active material for a lithium ion non-aqueous electrolyte secondary battery because the output resistance of the secondary battery is significantly reduced.

Further, at least lithium or titanium of the lithium titanium composite oxide is selected from the group consisting of other metal elements such as Na, K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu, Zn and Nb. Those substituted with one kind of element are also preferable.

A preferred lithium-titanium composite oxide as the negative electrode active material includes a lithium-titanium composite oxide represented by the following general formula (2).
_{Li x Ti y M z O 4} (2)
(In the general formula (2), M is Na, K, Co, Al, Fe, Ti, Mg, Cr, Ga, Cu.
, Zn and Nb represents at least one element selected from the group. Further, in the general formula (2), 0.7 ≦ x ≦ 1.5, 1.5 ≦ y ≦ 2.3, and 0 ≦ z ≦ 1.6 are the cases of doping and dedoping of lithium ions. It is preferable because the structure of is stable. )

<2-1-3-4. Negative electrode configuration, physical characteristics, preparation method>
A known technical configuration can be adopted for the negative electrode, the electrode conversion method, and the current collector containing the active material, but any one or more of the following items (I) to (VI) are shown below. It is desirable to satisfy at the same time.

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

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

(III) Ratio of thickness of current collector to negative electrode active material layer The ratio of thickness of current collector to negative electrode active material layer is not particularly limited, but "(one side immediately before the injection process of non-aqueous electrolyte solution) The value of "Negative electrode active material layer thickness) / (thickness of current collector)" is preferably 150 or less, more preferably 20 or less, particularly preferably 10 or less, and preferably 0.1 or more. 4 or more is more preferable, and 1 or more is particularly preferable.
If the ratio of the thickness of the current collector to the negative electrode active material layer exceeds the above range, the current collector may generate heat due to Joule heat during high current density charging / discharging of the secondary battery. Further, if it falls below the above range, the volume ratio of the current collector to the negative electrode active material may increase, and the capacity of the secondary battery may decrease.

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

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

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

The type of solvent for forming the slurry is particularly limited as long as it is a solvent capable of dissolving or dispersing the negative electrode active material, the binder, and the thickener and the conductive material used as needed. However, either an aqueous solvent or an organic solvent may be used.

Examples of the aqueous solvent include water, alcohol and the like, and examples of the organic solvent include N-methylpyrrolidone (NMP), dimethylformamide, dimethylacetamide, methylethylketone, cyclohexanone, methyl acetate, methyl acrylate, diethyltriamine. , N, N-dimethylaminopropylamine, tetrahydrofuran (THF), toluene, acetone, diethyl ether, dimethylacetamide, hexamethylphosphalamide, dimethylsulfoxide, benzene, xylene, quinoline, pyridine, methylnaphthalene, hexane, etc. Can be mentioned.
In particular, when an aqueous solvent is used, it is preferable to include a dispersant or the like in addition to the thickener and slurry using a latex such as SBR.
As these solvents, one type may be used alone, or two or more types may be used in any combination and ratio.

The ratio of the binder to 100 parts by mass of the negative electrode active material is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, further preferably 0.6 part by mass or more, and preferably 20 parts by mass or less. It is more preferably 15 parts by mass or less, further preferably 10 parts by mass or less, and particularly preferably 8 parts by mass or less. When the ratio of the binder to the negative electrode active material is within the above range, the ratio of the binder that does not contribute to the battery capacity does not increase, so that the battery capacity is unlikely to decrease. Further, the strength of the negative electrode is less likely to decrease.

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

When the slurry contains a fluorine-based polymer typified by polyvinylidene fluoride as a main component, the ratio of the binder to 100 parts by mass of the negative electrode active material is preferably 1 part by mass or more, more preferably 2 parts by mass or more. Preferably, 3 parts by mass or more is further preferable, 15 parts by mass or less is preferable, 10 parts by mass or less is more preferable, and 8 parts by mass or less is further preferable.

Thickeners are commonly used to adjust the viscosity of the slurry. The thickener is not particularly limited, and specific examples thereof include carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein, and salts thereof. These 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 100 parts by mass of the negative electrode active material is usually 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and more preferably 0.6 parts by mass or more. The ratio is usually 5 parts by mass or less, preferably 3 parts by mass or less, and more preferably 2 parts by mass or less. When the ratio of the thickener to the negative electrode active material is within the above range, the coating property of the slurry is good. Further, the ratio of the negative electrode active material to the negative electrode active material layer becomes appropriate, and the problem of a decrease in battery capacity and the problem of an increase in resistance between the negative electrode active materials are less likely to occur.

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

<2-1-4. Positive electrode>
The positive electrode used in the non-aqueous electrolyte secondary battery will be described below.

<2-1-4-1. Positive electrode active material>
The positive electrode active material used for the positive electrode will be described below.

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

The transition metal of the lithium transition metal composite oxide is preferably V, Ti, Cr, Mn, Fe, Co, Ni, Cu or the like, and specific examples of the composite oxide are lithium-cobalt composite oxidation such _{as LiCoO 2.} Materials, lithium-nickel composite oxides such as _{LiNiO 2 , lithium-manganese composite oxides such as LiMnO 2} , LiMn ₂ O ₄ , Li ₂ MnO _4, and transition metal atoms that are the main constituents of these lithium transition metal composite oxides. Partially replaced with other metals such as Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn, W, etc. Can be mentioned.

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

On the other hand, cobalt is an expensive metal with a small amount of resources, and 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. It is also desirable to use manganese as the main component as the transition metal. That is, a lithium-nickel-cobalt-manganese composite oxide is particularly preferable.

Further, a lithium-manganese composite oxide having a spinel-type structure is also preferable in consideration of stability as a compound and procurement cost due to ease of production. That is, among the above specific examples, LiMn ₂ O ₄ , LiMn _1.8 Al _0.2 O ₄ , Li _1.1 Mn _1.9 Al _0.1 O ₄ , LiMn _1.5 Ni _0.5 O _4, etc. Can also be mentioned as a preferable specific example.

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 of the phosphoric acid compound include, for example, 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. Examples thereof include those substituted with other metals such as Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn and W. ..
Of these, lithium iron-phosphoric acid compounds are preferable 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.

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

The transition metal of the lithium-containing transition metal borate compound is preferably V, Ti, Cr, Mn, Fe, Co, Ni, Cu or the like, and specific examples of the borate compound are hobo such as _{LiFeBO 3.} Iron _{acid, cobalt borates such as LiCoBO 3} , and some of the transition metal atoms that are the main constituents of these lithium transition metal borate compounds are Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Examples thereof include those substituted with other metals such as Cu, Zn, Mg, Ga, Zr, Si, Nb, Mo, Sn and W.

Further, as the positive electrode used in the non-aqueous electrolyte secondary battery, the lithium transition metal oxide represented by the composition formula (14) is used.
Li _a1 Ni _b1 Co _c1 M _d1 O ₂ ... (14)
(In the formula (14), the numerical values of 0.90 ≦ a1 ≦ 1.10, 0.50 ≦ b1 ≦ 0.98, 0.01 ≦ c1 <0.50, 0.01 ≦ d1 <0.50 are shown. , B1 + c1 + d1 = 1. M represents at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti and Er.)

Suitable specific examples of the lithium transition metal oxide represented by the composition formula (14) include, for example, LiNi _0.85 Co _0.10 Al _0.05 O ₂ , LiNi _0.80 Co _0.15 Al _{0. 05} O ₂ , LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , Li _1.05 Ni _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 and the} like can be mentioned.

It is preferable that the transition metal oxide having the composition formula (14) is represented by the following composition formula (15). This is because the alkaline impurities and the compound represented by the general formula (C) react favorably, and the gas suppressing effect during high-temperature storage is further enhanced.
Li _a2 Ni _b2 Co _c2 M _d2 O ₂ ... (15)
(In the formula (15), the numerical values of 0.90 ≦ a2 ≦ 1.10, 0.50 ≦ b2 ≦ 0.90, 0.05 ≦ c2 ≦ 0.30, 0.05 ≦ d2 ≦ 0.30 are shown. , And b2 + c2 + d2 = 1. M represents at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti and Er.)

It is more preferable that the transition metal oxide having the composition formula (14) is represented by the following composition formula (16). This is because the alkaline impurities and the compound represented by the general formula (C) react favorably, and the gas suppressing effect at the time of high temperature storage is further enhanced.
Li _a3 Ni _b3 Co _c3 M _d3 O ₂ ... (16)
(In the formula (16), the numerical values of 0.90 ≦ a3 ≦ 1.10, 0.50 ≦ b3 ≦ 0.80, 0.10 ≦ c3 ≦ 0.30, and 0.10 ≦ d3 ≦ 0.30 are shown. , And b3 + c3 + d3 = 1. M represents at least one element selected from the group consisting of Mn, Al, Mg, Zr, Fe, Ti and Er.)

Suitable specific examples of the lithium transition metal oxide represented by the composition formula (16) include, for example, LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , Li _1.05 Ni _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 and the} like can be mentioned.

In the composition formula, M is preferably Mn or Al. The structural stability of the transition metal oxide is enhanced, and structural deterioration during repeated charging and discharging is suppressed. Among them, Mn is more preferable.

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-mentioned 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.

Among them, the above-mentioned lithium-manganese composite oxide having a spinel-type structure and the lithium-containing transition metal phosphoric acid compound having an olivine-type structure are preferable.
Further, as the transition metal of the lithium-containing transition metal phosphoric acid compound, the above-mentioned one can be used. The same applies to the preferred embodiment.

(2) Method for Producing Positive Electrode Active Material The method for producing the positive electrode active material is not particularly limited as long as it does not exceed the gist of the invention according to the present embodiment, but some methods can be mentioned, and a method for producing an inorganic compound can be mentioned. A general method is used as.
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 other elements. 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. do it,
A method of obtaining an active material by drying and molding it with a spray dryer or the like to obtain a spherical or elliptical spherical precursor _{, adding a Li source such as LiOH, Li 2} CO ₃ , or LiNO ₃ to the precursor and firing at a high temperature 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. 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.

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

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

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, 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. As described above, cobalt or nickel is an expensive metal with a small amount of resources, and is not preferable in terms of cost because the amount of active material used is large in a large battery that requires a high capacity such as for automobile applications. Therefore, it is desirable to use manganese as a main component as a cheaper transition metal.

(Conductive material)
As the conductive material, a known conductive material can be arbitrarily used. Specific examples include metal materials such as copper and nickel; graphite such as natural graphite and artificial graphite (graphite); carbon black such as acetylene black; carbonaceous materials such as amorphous carbon such as needle coke; and the like. 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 for producing 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 for producing the electrode.

When the positive electrode is produced by the coating method, the binder is not particularly limited as long as it is a material that is dissolved or dispersed in the liquid medium used in the electrode production, and specific examples thereof include polyethylene, polypropylene, polyethylene terephthalate, and polymethyl. Resin-based polymers such as methacrylate, aromatic polyamide, cellulose, and nitrocellulose;
Rubbery polymers such as SBR (styrene / butadiene rubber), NBR (acrylonitrile / butadiene rubber), fluororubber, isoprene rubber, butadiene rubber, ethylene / propylene rubber;
Styrene / butadiene / styrene block copolymer or hydrogen additive thereof, EPDM (ethylene / propylene / diene ternary copolymer), styrene / ethylene / butadiene / ethylene copolymer, styrene / isoprene / styrene block copolymer or Thermoplastic elastomer-like polymer such as the hydrogenated product;
Soft resinous polymers such as syndiotactic-1,2-polybutadiene, polyvinyl acetate, ethylene / vinyl acetate copolymers, propylene / α-olefin copolymers;
Fluorine-based polymers such as polyvinylidene fluoride (PVDF), polytetrafluoroethylene, fluorinated polyvinylidene fluoride, and polytetrafluoroethylene / ethylene copolymer;
Polymer compositions having ionic conductivity of alkali metal ions (particularly lithium ions); and the like.
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. 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 content 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. Furthermore, it also leads to avoiding a decrease in battery capacity and conductivity.

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

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

(Thickener)
When an aqueous medium is used as the liquid medium for forming the slurry, it is preferable to use a thickener and a latex such as styrene-butadiene rubber (SBR) to form a slurry. Thickeners are commonly used to adjust the viscosity of the slurry.

The thickener is not limited as long as the effect of the invention according to the present embodiment is not significantly limited, but specifically, carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, ethyl cellulose, polyvinyl alcohol, oxidized starch, phosphorylated starch, casein. And these salts and the like. These may be used alone or in any combination and ratio of two or more.

When a thickener is used, the ratio of the thickener to the total mass of the positive electrode active material and the thickener is preferably 0.1% by mass or more, more preferably 0.5% by mass or more. It is more preferably 0.6% by mass or more, 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 is within the above range, the coating property of the slurry is good, and the ratio of the active material in the positive electrode active material layer is sufficient, so that the capacity of the secondary battery is lowered. And the problem of increased resistance between the positive electrode active materials can be easily avoided.

(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 charging / discharging is performed particularly at a high current density of the secondary battery. The characteristics are good. Further, the conductivity between the active materials is less likely to decrease, and the battery resistance is less likely to increase.

(Current collector)
The material of the positive electrode current collector is not particularly limited, and any known material can be used. Specific examples include metal materials such as aluminum, stainless steel, nickel plating, titanium, and tantalum; 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 of the secondary battery. Further, the volume ratio of the current collector to the positive electrode active material is unlikely to increase, and a decrease in battery capacity can be prevented.

(Electrode area)
From the viewpoint of improving the stability at high output and high temperature, the area of the positive electrode active material layer is preferably large with respect to the outer surface area of the battery outer case. Specifically, the total area of the electrode areas of the positive electrode with respect to the surface area of the exterior of the non-aqueous electrolyte secondary battery is preferably 20 times or more, 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 a 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 secondary 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 is designed so that the discharge capacity is fully charged, preferably 3 Ah (ampere hour), more preferably 4 Ah or more, preferably 20 Ah or less, and more preferably 10 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.

<2-1-5. Separator>
In a non-aqueous electrolyte secondary battery, a separator is usually interposed between the positive electrode and the negative electrode in order to prevent a short circuit. In this case, the non-aqueous electrolyte solution is usually used by impregnating this separator.

The material and shape of the separator are not particularly limited, and any known separator can be used as long as the effects of the invention according to the present embodiment are not significantly impaired. Among them, resins, glass fibers, inorganic substances and the like formed of a material stable to a non-aqueous electrolyte solution are used, and it is preferable to use a porous sheet or a non-woven fabric-like material having excellent liquid retention properties.

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

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

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

The average pore size of the separator is also arbitrary, but is preferably 0.5 μm or less, more preferably 0.2 μm or less, and preferably 0.05 μm or more. When the average hole diameter is within the above range, a short circuit is unlikely to occur. Further, the film resistance does not become too large, and it is possible to prevent the rate characteristic of the secondary battery from deteriorating.

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

As the form of the separator, a thin film such as a non-woven fabric, a woven cloth, or a microporous film is used. As the thin film-shaped separator, one having an average 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 are used on both sides of the positive electrode, and a fluororesin is used as a binder to form a porous layer.

<2-1-6. 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) is preferably 40% or more, more preferably 50% or more, and preferably 95% or less, 90%. The following is more preferable. When the electrode group occupancy rate is within the above range, the battery capacity is unlikely to be reduced. In addition, since an appropriate gap space can be secured, the internal pressure rises due to the expansion of the member due to the high temperature of the battery and the increase of the vapor pressure of the liquid component of the non-aqueous electrolyte solution, so that the battery can be used as a secondary battery. It is possible to reduce various characteristics such as charge / discharge repetition performance and high temperature storage characteristics, and to avoid the case where the gas release valve that releases the internal pressure to the outside operates.

(Current collector structure)
The current collecting structure is not particularly limited, but in order to more effectively improve the discharge characteristics by 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 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, a PTC (Positive Temperature Coafficient) thermistor whose resistance increases when abnormal heat generation or excessive current flows, a thermal fuse, and a current flowing in the circuit due to a sudden rise in battery internal pressure or internal temperature during abnormal heat generation are cut off. Examples include a valve (current cutoff valve). It is preferable to select the protective element under conditions that do not operate under normal use with a high current, and it is more preferable to design the battery so as not to cause abnormal heat generation or thermal runaway even without the protective element.

(Exterior body)
The non-aqueous electrolyte secondary battery 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 invention according to the present embodiment is not significantly impaired.

The material of the outer case is not particularly limited as long as it is a substance stable to the non-aqueous electrolyte solution used. Specifically, a nickel-plated steel plate, stainless steel, aluminum or aluminum alloy, magnesium alloy, metals such as nickel and titanium, or a laminated film (laminated film) of resin and aluminum foil is used. From the viewpoint of weight reduction, aluminum or aluminum alloy metal or laminated film is preferably used.
In the outer case using the above metals, the metals are welded together by laser welding, resistance welding, or ultrasonic welding to form a sealed and sealed structure, or the above metals are used to caulk the structure via a resin gasket. There are things to do. Examples of the outer case using the above-mentioned laminated film include a case in which resin layers are heat-sealed to form a sealed and sealed structure. In order to improve the sealing property, a resin different from the resin used for the laminate film may be interposed between the resin layers. In particular, when the resin layer is heat-sealed via the current 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 outer case 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.

<2-2. Non-aqueous electrolyte primary battery ＞
A material capable of occluding metal ions is used for the positive electrode, and a material capable of releasing metal ions is used for the negative electrode. As the positive electrode material, a transition metal oxide such as graphite fluoride or manganese dioxide is preferable. As the negative electrode material, a simple substance such as zinc or lithium is preferable. As the non-aqueous electrolyte solution, the above-mentioned non-aqueous electrolyte solution is used.

<2-3. Metal ion capacitor ＞
A material capable of forming an electric double layer is used for the positive electrode, and a material capable of occluding and releasing metal ions is used for the negative electrode. Activated carbon is preferable as the positive electrode material. Further, as the negative electrode material, a carbonaceous material is preferable. As the non-aqueous electrolyte solution, the above-mentioned non-aqueous electrolyte solution is used.

<2-4. Electric Double Layer Capacitor>
A material capable of forming an electric double layer is used for the electrode. Activated carbon is preferable as the electrode material. As the non-aqueous electrolyte solution, the above-mentioned non-aqueous electrolyte solution is used.

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

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

The various analysis methods in the following synthesis examples are as follows.
[Gas Chromatography (GC) Analysis]
100 μL of the sample was dissolved in 1 mL of hexane. The obtained solution was analyzed by a GC analyzer (GC-2025 manufactured by Shimadzu Corporation). The conditions are as follows.
(Measurement condition)
Column: HP1 (length 30 m, inner diameter 0.53 mm, film thickness 2.65 μm, manufactured by GL Sciences)
Injection volume: 1 μL
Detector: FID
Temperature: 50 ° C → 280 ° C, temperature rise at 10 ° C / min (analysis conditions)
Software: GC-solution ver. Made by Shimadzu Corporation. 2.43.00
Settings: Slope = 3, Slope = 1000, Drift = 0, T.I. DBL = 1000, Min. Area / Height = 1000

The purity is determined by combining cis- and trans-1,3-bis (isocyanatomethyl) cyclohexane when the total area of the peaks analyzed under the above analysis conditions excluding those derived from the solvent is taken as 100%. It was calculated as the ratio of the peak area.
Among the peaks analyzed under the above analytical conditions, the cis / trans ratio is determined by cis- and trans-1,3-bis (isocyanatomethyl) cyclohexane, or the raw materials thereof, cis- and trans-1,3-bis (cis- and trans-1,3-bis). It was expressed as a ratio when the total value of the peak areas of aminomethyl) cyclohexane was set to 100. If any of the peaks was not detected under the above analysis conditions, it was set to 0.

<Synthesis Example 1> Synthesis of 1,3-bis (isocyanatomethyl) cyclohexane (cis / trans ratio 100/0) 1,3-bis (aminomethyl) cyclohexane (1.00 g, cis / trans ratio 100/0) And 1,8-bis (dimethylamino) naphthalene (6.03 g) were dissolved in dichloromethane (70 mL), trichloromethyl chloroformate (1.02 mL) was added dropwise with stirring at 0 ° C., and the mixture was stirred for 30 minutes. The reaction mixture was diluted with dichloromethane (140 mL), washed 5 times with 1N aqueous hydrochloric acid solution (70 mL), once with 1N aqueous sodium hydroxide solution (70 mL), and once with saturated aqueous sodium chloride solution (140 mL). The organic layer was dehydrated with anhydrous sodium sulfate and then the solvent was distilled off under reduced pressure to obtain the desired product (1.23 g, yield 90%). The purity estimated by GC analysis was 99.0% and the cis / trans ratio was 100/0.

<Synthesis Example 2> Synthesis of 1,3-bis (isocyanatomethyl) cyclohexane (cis / trans ratio 18.7 / 81.3) 1,3-bis (aminomethyl) cyclohexane (1.00 g, cis / trans ratio) 1,3-Bis (isocyanatomethyl) cyclohexane was synthesized (1.27 g, yield 93%) in the same manner as in Synthesis Example 1 except that 20.9 / 79.1) was used as a raw material. The purity estimated by GC analysis was 97.4% and the cis / trans ratio was 18.7 / 81.3.

<Synthesis Example 3> Synthesis of 1,3-bis (isocyanatomethyl) cyclohexane (cis / trans ratio 75.8 / 24.2) 1,3-bis (aminomethyl) cyclohexane (1.0 g, cis / trans ratio) 1,3-Bis (isocyanatomethyl) cyclohexane was synthesized (1.26 g, yield 92%) in the same manner as in Synthesis Example 1 except that 74.3 / 25.7) was used as a raw material. The purity estimated by GC analysis was 99.0% and the cis / trans ratio was 75.8 / 24.2.

<Example 1-1, Comparative Examples 1-1 to 1-3>
[Example 1-1]
[Preparation of non-aqueous electrolyte solution]
In a dry argon atmosphere, in a mixed solvent (mixed volume ratio 3: 4: 3) consisting of ethylene carbonate (also referred to as "EC"), ethylmethyl carbonate (also referred to as "EMC") and diethyl carbonate (also referred to as "DEC"). , Electrolyte LiPF ₆ , additives vinylene carbonate (also referred to as "VC") and monofluoroethylene carbonate (also referred to as "MFEC"), and 1,3-bis (isocyanatomethyl) obtained in Synthesis Example 3. ) Cyclohexane (cis / trans ratio 75.8 / 24.2) was added to the concentration shown in Table 1 to prepare the non-aqueous electrolyte solution of Example 1-1.

[Preparation of positive electrode]
_{97 parts by mass of lithium cobalt oxide (LiCoO 2} ) as a positive electrode active material, 1.5 parts by mass of acetylene black as a conductive material, and 1.5 parts by mass of polyvinylidene fluoride (PVdF) as a binder, N-methylpyrrolidone. It was mixed with a disperser in a 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]
Natural graphite powder as the negative electrode active material, aqueous dispersion of sodium carboxymethyl cellulose as a thickener (concentration of sodium carboxymethyl cellulose 1% by mass), aqueous dispersion of styrene-butadiene rubber as a binder (concentration of styrene-butadiene rubber 50) Mass%) was added and mixed with a disperser to form a slurry. This slurry was uniformly applied to one side of a copper foil having a thickness of 10 μm, dried, and then pressed to obtain a negative electrode. In the negative electrode after drying, the mass ratio was such that natural graphite: sodium carboxymethyl cellulose: styrene-butadiene rubber = 98: 1: 1.

[Manufacturing of lithium secondary battery]
The above positive electrode, negative electrode, and polypropylene separator can be used as the negative electrode, separator, positive electrode, and so on.
A battery element was manufactured by laminating the separator and the negative electrode in this order. This battery element is inserted 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 the bag, and then a non-aqueous electrolyte solution is placed in the bag. Was injected into the battery and vacuum-sealed to prepare a sheet-shaped lithium secondary battery.

[Initial charge / discharge test]
With the lithium secondary battery sandwiched between glass plates and pressurized, the lithium secondary battery was charged with a constant current of 0.05 C for 10 hours at 25 ° C., and then discharged at a constant current of 0.2 C to 2.8 V. Further, after constant current-constant voltage charging (also referred to as "CC-CV charging") (0.05C cut) to 4.1V with a current corresponding to 0.2C, the mixture was left at 60 ° C. for 24 hours. .. After the battery was sufficiently cooled, it was discharged to 2.8 V with a constant current of 0.2 C. Then, after CC-CV charging (0.05C cut) to 4.3V at 0.2C, the battery was discharged again to 2.8V with a constant current of 0.2C, and the discharging capacity at this time was taken as the initial capacity.
Here, 1C represents a current value for discharging the reference capacity of the battery in 1 hour, and 0.2C represents, for example, 1/5 of the current value. The same applies hereinafter.

[High temperature storage durability test]
The lithium secondary battery subjected to the initial charge / discharge test is CC-CV charged (0.05C cut) at 0.2C to 4.3V at 25 ° C., and then stored at a high temperature at 60 ° C. for 14 days. It was. Then, at 25 ° C., a constant current discharge of 0.2 C to 2.8 V is performed, then CC-CV charging (0.05 C cut) is performed to 4.3 V at 0.2 C, and then 2 at a constant current of 0.2 C. The current was discharged again to 8.V, and the discharge capacity at this time was taken as the capacity after storage.

Using the lithium secondary battery produced above, the above initial charge / discharge test and high temperature storage durability test were carried out. The evaluation results are shown in Table 1 as relative values when Comparative Example 1-1, which will be described later, is set to 100.0%. The same applies to the following Comparative Examples 1-2 and 1-3.

[Comparative Example 1-1]
The non-aqueous electrolytic solution of Comparative Example 1-1 was prepared in the same manner as in Example 1-1 except that 1,3-bis (isocyanatomethyl) cyclohexane was not added to the basic electrolytic solution. A lithium secondary battery was produced in the same manner as in Example 1-1 except that the non-aqueous electrolyte solution of Comparative Example 1-1 was used as the electrolytic solution, and an initial charge / discharge test and a high temperature storage durability test were carried out.

[Comparative Example 1-2]
In place of the 1,3-bis (isocyanatomethyl) cyclohexane obtained in Synthesis Example 3 in the basic electrolytic solution, the 1,3-bis (isocyanatomethyl) cyclohexane (cis / trans ratio 100/0) obtained in Synthesis Example 1 was used. The non-aqueous electrolyte solution of Comparative Example 1-2 was prepared in the same manner as in Example 1-1 except that the above was added. A lithium secondary battery was produced in the same manner as in Example 1-1 except that the non-aqueous electrolyte solution of Comparative Example 1-2 was used as the electrolytic solution, and an initial charge / discharge test and a high temperature storage durability test were carried out.

[Comparative Example 1-3]
In place of the 1,3-bis (isocyanatomethyl) cyclohexane obtained in Synthesis Example 3 in the basic electrolytic solution, the 1,3-bis (isocyanatomethyl) cyclohexane (cis / trans ratio 18.7 /) obtained in Synthesis Example 2 was used. The non-aqueous electrolyte solution of Comparative Example 1-3 was prepared in the same manner as in Example 1-1 except that 81.3) was added. A lithium secondary battery was produced in the same manner as in Example 1-1 except that the non-aqueous electrolyte solution of Comparative Example 1-2 was used as the electrolytic solution, and an initial charge / discharge test and a high temperature storage durability test were carried out.

From Table 1, when the non-aqueous electrolyte solution of Example 1-1 was used, as compared with the case where neither compound (1) nor compound (2) was added (Comparative Example 1-1), the lithium secondary battery It was found that the initial capacity was improved and the decrease in capacity after storage was suppressed. On the other hand, in the case of the non-aqueous electrolyte solution containing only the compound (1) (Comparative Example 1-2), the initial capacity of the lithium secondary battery was improved, but the suppression of the capacity decrease after storage was insufficient. Further, even when both the compound (1) and the compound (2) are contained, lithium is similarly used in the case of a non-aqueous electrolyte solution in which these ratios are not the specific ratios of the present invention (Comparative Example 1-3). Although the initial capacity of the secondary battery was improved, the suppression of the capacity decrease after storage was insufficient. Therefore, it is clear that the lithium secondary battery using the non-aqueous electrolyte solution according to the embodiment of the present invention has superior characteristics.

<Example 2-1, Comparative Examples 2-1 to 2-3, Reference Example 2-1>
[Example 2-1]
[Preparation of non-aqueous electrolyte solution]
Under a dry argon atmosphere, a mixed solvent consisting of EC, EMC, dimethyl carbonate (also referred to as "DMC") and methyl acetate (mixed volume ratio 20:10:60:10), LiPF _{6 as} an electrolyte; and vinylene as an additive. Carbonate (also referred to as "VC"), monofluoroethylene carbonate (also referred to as "MFEC"), lithium difluorophosphate (LiPO ₂ F ₂ ), methylphenyl carbonate (also referred to as "MPC"), lithium fluorosulfonate (LiFSO ₃₎ ) and lithium bis (fluorosulfonyl) imide _{(Li (FSO 2) 2 N} ); and obtained in synthesis example 3 1,3-bis (isocyanatomethyl) cyclohexane (cis / trans ratio 75.8 / 24.2 ) Was added to the concentration shown in Table 2 to prepare the non-aqueous electrolyte solution of Example 2-1.

[Preparation of positive electrode]
_{97 parts by mass of LiNi 0.8} Co _0.15 Al _0.05 O ₂ as the positive electrode active material, 1.5 parts by mass of acetylene black as the conductive material, and 1.5 parts by mass of polyvinylidene fluoride (PVdF) as the binder. The parts were 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. Then, it was punched into a disk shape having a diameter of 12.5 mm to obtain a positive electrode for a non-aqueous electrolyte battery (coin type).

[Preparation of negative electrode]
Natural graphite powder as the negative electrode active material, aqueous dispersion of sodium carboxymethyl cellulose as a thickener (concentration of sodium carboxymethyl cellulose 1% by mass), aqueous dispersion of styrene-butadiene rubber as a binder (concentration of styrene-butadiene rubber 50) Mass%) was added and mixed with a disperser to form a slurry. This slurry was uniformly applied to one side of a copper foil having a thickness of 10 μm, dried, and then pressed. In the negative electrode after drying, the mass ratio was such that natural graphite: sodium carboxymethyl cellulose: styrene-butadiene rubber = 98: 1: 1. Then, it was punched into a disk shape having a diameter of 12.5 mm to obtain a negative electrode for a non-aqueous electrolyte battery (coin type).

[Manufacturing of non-aqueous electrolyte battery (coin type)]
Using the above positive electrode and negative electrode and the non-aqueous electrolyte solution prepared in each Example and Comparative Example, a coin-shaped cell was produced by the following procedure. That is, the positive electrode was housed in a stainless steel can body that also serves as a positive electrode conductor, and the negative electrode was placed on the positive electrode via a polypropylene separator impregnated with an electrolytic solution described later. A non-aqueous electrolyte battery (coin type) was produced by caulking and sealing the can body and the sealing plate that also serves as the negative electrode conductor via an insulating gasket.

[Initial charge / discharge test]
A non-aqueous electrolyte battery (coin type) was charged at 25 ° C. with a current corresponding to 0.05 C for 4 hours, and then discharged at a constant current of 0.2 C to 2.5 V. Further, after a constant current charge to 4.1 V with a current corresponding to 0.1 C, a constant current discharge to 2.5 V was performed at 0.2 C. Further, after constant current charging to 4.1 V with a current corresponding to 0.1 C, constant current discharge to 2.5 V at 0.2 C was performed, and the discharge capacity at this time was taken as the initial capacity.
The above initial charge / discharge test was carried out using the non-aqueous electrolyte battery (coin type) produced above. The evaluation results are shown in Table 2 as relative values when Comparative Example 2-1 described later is taken as 100%. The same applies to the following Comparative Examples 2-1 to 2-3 and Reference Example 2-1.

[Comparative Example 2-1]
The non-aqueous electrolytic solution of Comparative Example 2-1 was prepared in the same manner as in Example 2-1 except that 1,3-bis (isocyanatomethyl) cyclohexane was not added to the basic electrolytic solution. Further, a non-aqueous electrolyte battery (coin type) was produced in the same manner as in Example 2-1 except that the non-aqueous electrolyte solution of Comparative Example 2-1 was used as the electrolytic solution, and an initial charge / discharge test was carried out.

[Comparative Example 2-2]
The 1,3-bis (isocyanatomethyl) cyclohexane obtained in Synthesis Example 1 was replaced with the 1,3-bis (isocyanatomethyl) cyclohexane obtained in Synthesis Example 3 in the basic electrolytic solution (cis / trans ratio 100/0). The non-aqueous electrolyte solution of Comparative Example 2-2 was prepared in the same manner as in Example 2-1 except that the above was added. Further, a non-aqueous electrolyte battery (coin type) was produced in the same manner as in Example 2-1 except that the non-aqueous electrolyte solution of Comparative Example 2-2 was used as the electrolytic solution, and an initial charge / discharge test was carried out.

[Comparative Example 2-3]
In place of the 1,3-bis (isocyanatomethyl) cyclohexane obtained in Synthesis Example 3 in the basic electrolytic solution, the 1,3-bis (isocyanatomethyl) cyclohexane (cis / trans ratio 18.7 /) obtained in Synthesis Example 2 was used. The non-aqueous electrolyte solution of Comparative Example 2-3 was prepared in the same manner as in Example 2-1 except that 81.3) was added. Further, a non-aqueous electrolyte battery (coin type) was produced in the same manner as in Example 2-1 except that the non-aqueous electrolyte solution of Comparative Example 2-3 was used as the electrolytic solution, and an initial charge / discharge test was carried out.

[Reference Example 2-1]
Reference Example in the same manner as in Example 2-1 except that hexamethylene diisocyanate (also referred to as “HDI”) was added to the basic electrolytic solution in place of 1,3-bis (isocyanatomethyl) cyclohexane obtained in Synthesis Example 3. A non-aqueous electrolyte solution of 2-1 was prepared. Further, a non-aqueous electrolyte battery (coin type) was produced in the same manner as in Example 2-1 except that the non-aqueous electrolyte solution of Reference Example 2-1 was used as the electrolytic solution, and an initial charge / discharge test was carried out.

From Table 2, when the non-aqueous electrolyte solution of Example 2-1 was used, it was compared with the non-aqueous electrolyte solution (Comparative Example 2-1) to which neither compound (1) nor compound (2) was added. It was found that the initial capacity of the electrolyte battery was improved. On the other hand, in the case of the non-aqueous electrolyte solution containing only the compound (1) (Comparative Example 2-2), the initial capacity of the non-aqueous electrolyte battery decreased. Further, even when both the compound (1) and the compound (2) are contained, the case where these ratios are not the specific ratio of the present invention in the case of a non-aqueous electrolyte solution (Comparative Example 2-3) is also non-existent. The initial capacity of the water-based electrolyte battery has decreased. Further, when another isocyanate compound was used instead of the compound (1) and the compound (2) (Reference Example 2-1), the initial volume decreased. Therefore, it is clear that the non-aqueous electrolyte battery using the non-aqueous electrolyte according to the present embodiment has superior characteristics.

In the examples and comparative examples shown in Tables 1 and 2 above, the various endurance test periods are modeled as relatively short periods, but significant differences have been confirmed. Since the actual use of the non-aqueous electrolyte secondary battery may last for several years, it can be understood that the difference between these results will be even more remarkable when long-term use is assumed.

By using the non-aqueous electrolyte solution according to the present invention as the electrolytic solution of the energy device, the initial capacity of the energy device is improved, and the capacity decrease after high temperature endurance storage is also suppressed. Therefore, the non-aqueous electrolyte solution according to the present invention can be suitably used in all fields such as electronic devices in which energy devices are used.
Further, the non-aqueous electrolyte solution according to the present invention and the energy device using the same can be used for various known applications in which the energy device is used. Specific examples of applications include laptop computers, pen input computers, mobile computers, electronic book players, mobile phones, mobile fax machines, mobile copies, mobile printers, portable audio players, small video cameras, headphone stereos, video movies, and LCDs. TVs, handy cleaners, portable CDs, mini discs, transceivers, electronic notebooks, calculators, memory cards, portable tape recorders, radios, backup power supplies, motors, automobiles, bikes, motorized bicycles, bicycles, lighting equipment, toys, game equipment, etc. Examples include watches, electric tools, strobes, cameras, household backup power supplies, office backup power supplies, load leveling power supplies, natural energy storage power supplies, lithium ion capacitors, and the like.

Claims (10)

A non-aqueous electrolyte solution for an energy device including a positive electrode and a negative electrode, wherein the non-aqueous electrolyte solution is used together with an electrolyte and a non-aqueous solvent.
(A) A diisocyanate having a cis structure represented by the formula (1) and a diisocyanate having a trans structure represented by the formula (2) are contained and
(B) The mass ratio of the content of the diisocyanate having the cis structure represented by the formula (1) to the content of the diisocyanate having the trans structure represented by the formula (2) is 30/70 to 99/1. ,
A non-aqueous electrolyte solution characterized by this.

(In the formula (1), the two R ^1s are each the same group and represent a saturated hydrocarbon group having 1 to 5 carbon atoms, and in the formula (2), the two R ^2s are each the same group. Represents a saturated hydrocarbon group having 1 to 5 carbon atoms. The non-aqueous electrolyte solution according to claim 1, ^{wherein R 1} in the formula (1) ^{and R 2} in the formula (2) are the same group. Claim 1 or the total content of the compound represented by the formula (1) and the compound represented by the formula (2) is 0.001% by mass or more and 5% by mass or less with respect to the total amount of the non-aqueous electrolyte solution. 2. The non-aqueous electrolyte solution according to 2. The non-aqueous electrolyte solution according to any one of claims 1 to 3, wherein the non-aqueous solvent contains a chain carboxylic acid ester. The non-aqueous electrolyte solution according to claim 4, wherein the content of the chain carboxylic acid ester with respect to the total amount of the non-aqueous solvent is 1% by volume or more and 50% by volume or less. Wherein as the electrolyte, containing LiPF _6, to the content of LiPF _6, the mass ratio of the total content of the above formula (1) compound represented by and compounds represented by the formula (2) is 0.00005 The non-aqueous electrolyte solution according to any one of claims 1 to 5, which is 0.1 or less. The non-aqueous electrolyte solution further comprises at least one compound selected from the group consisting of a cyclic carbonate having a carbon-carbon unsaturated bond, a fluorine-containing cyclic carbonate, a lithium imide salt, a monofluorophosphate and a difluorophosphate. The non-aqueous electrolyte solution according to any one of claims 1 to 6, which contains. Total of at least one compound selected from the group consisting of a cyclic carbonate having a carbon-carbon unsaturated bond, a fluorine-containing cyclic carbonate, a lithium imide salt, a monofluorophosphate and a difluorophosphate, based on the total amount of the non-aqueous electrolyte solution. The non-aqueous electrolyte solution according to claim 7, wherein the content is 0.001% by mass or more and 10% by mass or less. The electrolyte _{contains LiPF 6} and is composed of a cyclic carbonate having a carbon-carbon unsaturated bond, a fluorine-containing cyclic carbonate, a lithium imide salt, a monofluorophosphate and a difluorophosphate with respect to the content of _{LiPF 6.} The non-aqueous electrolyte solution according to claim 7 or 8, wherein the mass ratio of the content of at least one compound selected from the group is 0.00005 or more and 0.5 or less. An energy device comprising a negative electrode, a positive electrode, and the non-aqueous electrolyte solution according to any one of claims 1 to 9.