JP5599357B2 - Non-aqueous secondary battery electrolyte and secondary battery using the same - Google Patents

Description

  The present invention relates to an electrolyte solution for a non-aqueous secondary battery containing an organic solvent, and a secondary battery using the same.

  Recently, secondary batteries called lithium ion batteries, which are attracting attention, use secondary batteries (so-called lithium ion secondary batteries) that use insertion and extraction of lithium in charge and discharge reactions, and precipitation and dissolution of lithium. They are roughly classified into secondary batteries (so-called lithium metal secondary batteries). These can obtain a large energy density as compared with lead batteries and nickel cadmium batteries. In recent years, portable electronic devices such as camera-integrated VTRs (video tape recorders), mobile phones, and notebook personal computers have been widely used by utilizing this characteristic. There is a strong demand for miniaturization, weight reduction and long life. Accordingly, as a power source for portable electronic devices, development of a battery, in particular, a secondary battery that is lightweight and obtains a high energy density is in progress.

  Examples of electrolytes for lithium ion secondary batteries and lithium metal secondary batteries (hereinafter, these may be simply referred to as lithium ion secondary batteries) include carbonate solvents such as propylene carbonate and diethyl carbonate. A combination with an electrolyte salt such as lithium hexafluorophosphate is widely used. This is because the conductivity is high and the potential is stable.

With respect to the composition of the electrolytic solution, a technique for incorporating various additives into the electrolytic solution has been proposed for the purpose of improving cycle characteristics and the like. For example, as an additive, silicon oxide such as tetramethoxysilane (for example, Patent Document 1) or a specific silyl group having a group (R ₃ Si—O—) in which a trialkylsilyl group and an ether bond are linked is used. Ester compounds and the like (for example, Patent Document 2), silane compounds having a trialkylsilyl group (R ₃ Si—) (for example, see Patent Document 3), silicon compounds having a carbonate group (for example, see Patent Document 4) Is used.

JP 2001-266938 A JP 2002-359001 A JP 2006-216553 A JP 2007-89735 A

Recent portable electronic devices are becoming more sophisticated and multifunctional, and accordingly, charging and discharging of secondary batteries tend to be repeated frequently, so that cycle characteristics tend to be deteriorated. In addition, further diversification of usage environments is expected, and improvement of performance corresponding to this is a problem. In order to cope with this, it is desired to further improve the cycle characteristics of the secondary battery.
The present invention has been made in view of the above points, and an object of the present invention is to provide a non-aqueous electrolyte solution having high cycle characteristics and low temperature characteristics, less self-discharge and excellent storage stability, and a secondary battery using the same. It is to provide.

  As a result of intensive studies in view of the above problems, the inventors have found that the inclusion of a siloxane oligomer having a specific structure improves cycle characteristics, has a high low-temperature discharge rate, and can reduce self-discharge. The present invention has been reached.

（前記一般式（１）中、Ｒ^１はアルキル基、アルケニル基または−ＯＲ^２基を表す。Ｒ^２はアルキル基またはアルケニル基を表す。Ｒ^１又は−ＯＲ^２の少なくとも一部は下記一般式（２）で表される置換基である。但し、前記シロキサンオリゴマーに含まれる一般式（１）で表される全部分構造におけるＲ^１と−ＯＲ^２の総モル量に対する、下記一般式（２）で表される置換基のモル分率は５モル％以上である。）

（前記一般式（２）中、Ｑ^１はアルキレン基を表し、Ｒ^３はアルキル基を表す。）
（２）前記シロキサンオリゴマーが、下記一般式（１−ａ）、一般式（１−ｂ）、一般式（１−ｃ）、一般式（１−ｄ）、及び一般式（１−ｅ）からなる群より選択される部分構造を含み、且つ、下記一般式（１−ａ）、一般式（１−ｂ）、一般式（１−ｃ）、一般式（１−ｄ）、及び一般式（１−ｅ）で表される部分構造のモル分率を、それぞれｘａ、ｘｂ、ｘｃ、ｘｄ及びｘｅとした時に、ｘｃ＋ｘｄ＋ｘｅで表される分岐モル分率が４０モル％以下であるシロキサンオリゴマーである（１）に記載の非水二次電池用電解液。

（前記一般式（１−ａ）〜一般式（１−ｅ）中、＊及び＊＊は、他の部分構造との連結部位であり、一般式（１−ａ）〜一般式（１−ｅ）で表される部分構造が連結する場合、＊＊と＊との部位で連結する。Ｒ^１及びＲ^２は、それぞれ前記一般式（１）におけるＲ^１及びＲ^２と同義である。）
（３）前記一般式（２）が下記一般式（３）で表されることを特徴とする（１）又は（２）に記載の非水二次電池用電解液。

（前記一般式（３）中、Ｒ^４はそれぞれ独立に、水素原子、アルキル基、アルケニル基、又はアリール基を表す。）
（４）前記置換基Ｒ^１及びＲ^２が炭素数１〜４のアルキル基又は炭素数２〜４のアルケニル基である（１）から（３）のいずれか１項に記載の非水二次電池用電解液。
（５）前記置換基Ｑ^１が炭素数１〜５のアルキレン基である（１）から（４）のいずれか１項に記載の非水二次電池用電解液。
（６）前記置換基Ｒ^３ が炭素数１〜４のアルキル基である、あるいはＲ^４が水素原子もしくは炭素数１〜４のアルキル基である（３）に記載の非水二次電池用電解液。
（７）前記置換基Ｒ^２が無置換のアルキル基、シアノ基で置換されたアルキル基、又はハロゲン原子で置換されたアルキル基である（１）から（６）のいずれか１項に記載の非水二次電池用電解液。
（８）前記シロキサンオリゴマーに含まれる一般式（１）で表される部分構造中、−ＯＲ^２が前記一般式（２）で表される置換基であり、前記シロキサンオリゴマーに含まれる一般式（１）で表される全部分構造におけるＲ^１と−ＯＲ^２の総モル量に対する前記一般式（２）で表される置換基のモル分率が２５モル％以上７５モル％以下である（１）から（７）のいずれか１項に記載の非水二次電池用電解液。
（９）周期律表第一族又は第二族に属する金属イオンもしくはその塩がリチウムイオンもしくはその塩である（１）から（８）のいずれか１項に記載の非水二次電池用電解液。
（１０）（１）から（９）のいずれか１項に記載の非水二次電池用電解液と、周期律表第一族又は第二族に属する金属イオンの挿入放出が可能な正極と、当該イオンの挿入放出又は溶解析出が可能な負極とを備える二次電池。
That is, the present invention has the following means.
(1) A metal ion or a salt thereof belonging to Group 1 or Group 2 of the periodic table, and 0.005 to 10% by mass of a siloxane oligomer containing a partial structure represented by the following general formula (1), an organic solvent An electrolyte for a non-aqueous secondary battery, characterized in that it is contained therein.

(In the general formula (1), R ¹ represents an alkyl group, an alkenyl group or —OR ² group. R ² represents an alkyl group or an alkenyl group. At least a part of R ¹ or —OR ² represents the following general formula. The substituent represented by (2), provided that the following general formula (2) with respect to the total molar amount of R ¹ and —OR ² in the entire partial structure represented by the general formula (1) contained in the siloxane oligomer: The molar fraction of the substituent represented by) is 5 mol% or more.)

(In the general formula (2), Q ¹ represents an alkylene group, and R ³ represents an alkyl group.)
(2) The siloxane oligomer is represented by the following general formula (1-a), general formula (1-b), general formula (1-c), general formula (1-d), and general formula (1-e). A partial structure selected from the group consisting of the following general formulas (1-a), (1-b), (1-c), (1-d), and ( 1-e) is a siloxane oligomer having a branched mole fraction represented by xc + xd + xe of 40 mol% or less when the molar fraction of the partial structure represented by 1-e) is xa, xb, xc, xd and xe, respectively. The electrolyte solution for nonaqueous secondary batteries as described in (1).

(In the general formula (1-a) to the general formula (1-e), * and ** are linking sites with other partial structures, and the general formula (1-a) to the general formula (1-e When the partial structures represented by) are linked, they are linked at the position of ** and * .R ¹ and R ² are respectively synonymous with R ¹ and R ² in the general formula (1).
(3) The electrolyte for a non-aqueous secondary battery according to (1) or (2), wherein the general formula (2) is represented by the following general formula (3).

(In the general formula (3), each R ⁴ independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an aryl group.)
(4) The non-aqueous secondary according to any one of (1) to (3), wherein the substituents R ¹ and R ² are an alkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms. Battery electrolyte.
(5) The electrolyte solution for a non-aqueous secondary battery according to any one of (1) to (4), wherein the substituent Q ¹ is an alkylene group having 1 to 5 carbon atoms.
(6) The electrolysis for non-aqueous secondary battery according to (3 ), wherein the substituent R ³ is an alkyl group having 1 to 4 carbon atoms, or R ⁴ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. liquid.
(7) The substituent R ^{2 according} to any one of (1) to (6), wherein the substituent R ² is an unsubstituted alkyl group, an alkyl group substituted with a cyano group, or an alkyl group substituted with a halogen atom. Electrolyte for non-aqueous secondary battery.
(8) In the partial structure represented by the general formula (1) contained in the siloxane oligomer, -OR ² is a substituent represented by the general formula (2), and the general formula ( The molar fraction of the substituent represented by the general formula (2) with respect to the total molar amount of R ¹ and —OR ² in the entire partial structure represented by 1) is 25 mol% or more and 75 mol% or less (1 The electrolyte solution for nonaqueous secondary batteries of any one of (7) to (7).
(9) The electrolysis for a non-aqueous secondary battery according to any one of (1) to (8), wherein the metal ion or salt thereof belonging to Group 1 or Group 2 of the periodic table is lithium ion or a salt thereof. liquid.
(10) The electrolyte for a nonaqueous secondary battery according to any one of (1) to (9), and a positive electrode capable of inserting and releasing metal ions belonging to Group 1 or Group 2 of the periodic table A secondary battery comprising a negative electrode capable of inserting and releasing or dissolving and depositing the ions.

The non-aqueous electrolyte of the present invention is a secondary battery equipped with the non-aqueous electrolyte by suppressing the decomposition of the electrolyte and improving the cycle characteristics, reducing the internal resistance, improving the low temperature characteristics, and stabilizing the positive electrode. It has an excellent effect of suppressing self-discharge.

It is sectional drawing which shows typically the structure of the lithium ion secondary battery which concerns on preferable embodiment of this invention. It is an expansion | deployment perspective view which shows the specific structure of the lithium ion secondary battery which concerns on preferable embodiment of this invention.

The electrolyte solution for a non-aqueous secondary battery of the present invention contains a siloxane oligomer having a specific substituent represented by each of the following general formulas. Thereby, it is considered that the chemical stability of the organic solvent such as ethylene carbonate forming the electrolyte is enhanced, and this leads to the operational effect of improving various characteristics in the secondary battery. The reason for this is as follows.
That is, in this type of secondary battery, when an oxidation-reduction reaction proceeds at the positive electrode and the negative electrode after repeated discharge and charge, decomposition of ethylene carbonate or the like constituting the electrolyte inevitably proceeds. On the other hand, a specific coating called SEI (Solid electrolyte Interface) is formed on the surface of the electrode material by the action of a specific additive or the like, and the effect of suppressing the decomposition may be exhibited. In the present invention, it is considered that the silicon compound having the specific substituent was involved in the formation of the SEI and exhibited an effect of suppressing decomposition of the electrolyte or the like. In particular, in the present invention, it is considered that the secondary battery exhibited a behavior that the above effect was exhibited not only in the negative electrode but also in the positive electrode, which led to a significant improvement in characteristics.
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. However, the description of constituent elements described below is an example (representative example) of an embodiment of the present invention, and is not specified by these contents. Various modifications can be made within the scope of the gist.

[Electrolyte for non-aqueous secondary battery]
(Specific siloxane oligomer compound)
The electrolytic solution of the present invention contains a siloxane oligomer compound having a partial structure represented by the following general formula (1).

In the general formula (1), R ¹ represents a hydrocarbon group or an —OR ² group. R ² represents an alkyl group or an alkenyl group . At least a part of R ¹ or —OR ² is a substituent represented by the following general formula (2). However, the molar fraction of the substituent represented by the following general formula (2) with respect to the total molar amount of R ¹ and —OR ² in the entire partial structure represented by the general formula (1) contained in the siloxane oligomer is 5 mol% or more.

In the general formula (2), Q ¹ represents an alkylene group, and R ³ represents an alkyl group.

Substituents R ¹ and R ²
Hydrocarbon groups which may R ¹ in the general formula (1) represents a hydrocarbon group, Ru alkyl or alkenyl Motodea.
Here, a preferable alkyl group when R ¹ represents an alkyl group is an alkyl group having 1 to 10 carbon atoms (methyl, ethyl, hexyl, cyclohexyl, etc.), and an alkyl group having 1 to 5 carbon atoms is more preferable. Further, an alkyl group having 1 to 3 carbon atoms is more preferable. A preferable alkenyl group in the case of representing an alkenyl group is an alkenyl group having 2 to 10 carbon atoms (vinyl, allyl, 2-cyclohexenyl, etc.), more preferably an alkenyl group having 2 to 5 carbon atoms, and 2 to 2 carbon atoms. More preferred is an alkenyl group of 3 . Na us, "from" herein used interchangeably with "~", is meant to include numerical values or numbers defined by the front and rear.

Formula (1) ^{R 1} represents -OR ² in the case -OR ² is an alkoxy group, the alkyl group represented by ^{R 2,} an alkyl group having from carbon number 1 10 (methyl, ethyl, butyl And a methyl group or an ethyl group is more preferable. That is, when —OR ² is an alkoxy group, it is preferably a methoxy group or an ethoxy group.

The hydrocarbon group typified by these alkyl groups may further have a substituent, and preferred substituents that can be introduced (hereinafter referred to as substituent T) include halogen atoms, alkyl groups, and aryl groups. , Heterocyclic group, cyano group, nitro group, alkoxy group, silyloxy group, acyloxy group, carbamoyloxy group, carbonyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group, acylamino group, aminocarbonylamino group, Alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkylsulfonylamino group, arylsulfonylamino group, mercapto group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, alkylsulfinyl group, a Rusurufiniru group, an alkylsulfonyl group, an arylsulfonyl group, an acyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, a carbamoyl group, and a silyl group.
More preferably, the substituent is an alkyl group, an aryl group, a cyano group, an alkoxy group, a silyloxy group, a carbonyloxy group, an alkoxycarbonyl group, an alkoxycarbonyloxy group, or a fluorine atom, and more preferably an aryl group, a cyano group, or an alkoxy group. A carbonyl group, a carbonyloxy group, and a fluorine atom.
Among these, R ² is preferably an unsubstituted alkyl group, an alkyl group substituted with a cyano group, or an alkyl group substituted with a halogen atom, and more preferably an unsubstituted alkyl group.

At least a part of —OR ² in the general formula (1) is a substituent represented by the general formula (2). The mole fraction of the substituent represented by the general formula (2) with respect to the total molar amount of R ¹ and —OR ² in the entire partial structure represented by the general formula (1) contained in the specific siloxane oligomer according to the present invention. The rate needs to be 5 mol% or more.

In the general formula (2), examples of the alkylene group represented by Q ¹ include a substituted or unsubstituted methylene group, ethylene group, or propylene group.
In the present specification, when the term “compound” is added at the end, it is used to mean a salt, a complex, or an ion thereof in addition to the compound itself. Moreover, it is the meaning including the derivative | guide_body accompanying a predetermined substituent etc. in the range with the desired effect. In the case of an organic acid or the like, the meaning includes an acid ester thereof. Further, in the present specification, when the term “group” is added to the end of a substituent, it means that the group may have an arbitrary substituent. Examples of the optional substituent include the substituent T.

Substituent R ³
R ³ represents an alkyl group, and examples of the alkyl group include the same alkyl groups represented by R ² in the general formula (1), and preferred examples are also the same.

  The substituent represented by the general formula (2) is preferably a substituent represented by the following general formula (3).

In the general formula (3), the alkyl group represented by R ^3, the general formula in (1) the same as the alkyl group represented by R ² are exemplified, and preferred examples are also the same.

Substituent R ⁴
R ⁴ each independently represents an alkyl group, an alkenyl group, an aryl group or a hydrogen atom, preferably an alkyl group or a hydrogen atom, and more preferably both are hydrogen atoms.

  The specific siloxane oligomer according to the present invention includes the following general formula (1-a), general formula (1-b), general formula (1-c), general formula (1-d), and general formula (1-e). A partial structure selected from the group consisting of:

The formula (1-a) represents an example of an embodiment that exists at the terminal of the specific siloxane oligomer among the partial structures represented by the general formula (1), and the formula (1-b) represents the formula (1-b). The aspect which comprises the chain structure in the partial structure represented by 1) is shown. The specific siloxane oligomer further has a branched structure containing at least one selected from the partial structures represented by the general formula (1-c), the general formula (1-d), and the general formula (1-e). The general formula (1-a), the general formula (1-b), the general formula (1-c), the general formula (1-d), and the general formula (1-e) may be used. When the mole fraction of the partial structure represented by x is xa, xb, xc, xd and xe, the branched mole fraction represented by xc + xd + xe is 40 mol% or less, indicating that the viscosity of the specific siloxane oligomer Is preferably from the viewpoint of being properly maintained, more preferably 30 mol% or less, and even more preferably 25 mol% or less. The mole fraction is a ratio when xa + xb + xc + xd + xe = 1 (100 mol%). At this time, the partial structure represented by the general formula (1-a), the general formula (1-b), the general formula (1-c), the general formula (1-d), and the general formula (1-e). However, the specific siloxane oligomer usually has a structure that can be displayed by selecting the partial structure.
The presence or absence of a branched structure or a crosslinked structure of the specific siloxane oligomer is confirmed by Si-NMR.

In the partial structure represented by the general formula (1) contained in the siloxane oligomer, —OR ² is a substituent represented by the general formula (2), and the general formula (1) contained in the siloxane oligomer. The molar fraction of the substituent represented by the general formula (2) with respect to the total molar amount of R ¹ and —OR ² in the entire partial structure represented is preferably 25 mol% or more and 75 mol% or less, More preferably, it is more than mol% and 70 mol% or less, More preferably, it is 25 mol% or more and 65 mol% or less.

  Specific examples of the specific siloxane oligomer according to the present invention [(Si-1) to (Si-13)] are branched by the content ratio of each substituent in the partial structure represented by the general formula (1) and Si-NMR measurement. Although the number average molecular weight obtained by the molar fraction and the styrene conversion by GPC measurement is listed below, the present invention is not limited to these.

  The content of the specific silicon compound in the non-aqueous solvent is preferably 0.005% by mass to 10% by mass, more preferably 0.01% by mass to 7% by mass, and more preferably 0.01% by mass to 5%. More preferably, it is 0.05% by mass or less and most preferably 5% by mass or less. This is because high chemical stability can be obtained in the electrolytic solution. Specifically, if the amount is less than 0.005% by mass, the chemical stability of the electrolytic solution may not be sufficiently and stably obtained. If the amount is more than 10% by mass, the main electrical properties of the electrochemical device may be reduced. This is because performance (for example, capacity characteristics in a battery) may not be sufficiently obtained.

(Synthesis of specific siloxane oligomer compounds)
In the condensation reaction between the alkoxysilane compound and the hydroxycarboxylic acid, the hydroxycarboxylic acid used as the acid catalyst is esterified by transesterification with the alkoxysilane to become HOQ ¹ COOR ² and further exchanged with the alkoxy group on the oligomer. Introduced onto the oligomer. At this time, when other alcohol [HO-Q ² -X] coexists, the other alcohol is exchanged with —OR ² group in the alkoxysilane compound and introduced into the oligomer (Scheme 1).
The other alcohol [HO-Q ² -X] may be present in the reaction solution from the beginning or may be added after the condensation has progressed.

^R 1, ^{R 2} and ^{Q 1} in Scheme 1 are respectively ^R 1, ^{R 2} and ^{Q 1} synonymous in Formula (1) and the general formula (2), ^{Q 2} has the same meaning as ^{Q 1} .

X is the same as the substituent T described in R ² , and more preferably, an alkyl group, an aryl group, a cyano group, an alkoxy group, a silyloxy group, a carbonyloxy group, an alkoxycarbonyloxy group, an alkoxycarbonyl group, a fluorine atom And more preferably an aryl group, a cyano group, a silyloxy group, a carbonyloxy group, an alkoxycarbonyl group, or a fluorine atom.

-Condensation conditions-composition ratio, temperature, distillation conditions Raw material charge ratio:
In the electrolytic solution preparation in the present invention, when the molar amount of the alkoxysilane compound charged is a and the molar amount of the hydroxycarboxylic acid charged is b, a preferable range of the charged molar ratio b / a is 0.1 to 2, More preferably, it is in the range of 0.2 to 1. A plurality of alkoxysilane compounds and hydroxycarboxylic acids having different structures may be mixed and used.

Reaction temperature, reaction time, etc .:
In the present invention, an alkoxysilane compound is obtained by condensing using hydroxycarboxylic acid as an acid catalyst, and then distilling off a volatile component derived from an unreacted raw material and a generated volatile component. The reaction temperature at that time depends on the boiling point of the alcohol produced during the condensation, but is preferably in the range of room temperature to 200 ° C, more preferably in the range of 50 ° C to 170 ° C, and still more preferably in the range of 80 ° C to 160 ° C. . Usually, the volatile component is distilled off at normal pressure, and then the reduced component is preferably heated at reduced pressure. The preferred temperature range at this time is 60 ° C. to 200 ° C., 100 ° C. To 160 ° C. is more preferable. The degree of vacuum is preferably gradually increased in the range of 600 mmHg to 5 mmHg, and finally the volatile matter is preferably distilled off in the range of vacuum of 100 mmHg to 5 mmHg and temperature of 100 ° C to 160 ° C. The temperature here is the temperature of the heat medium for heating the reactor.

Specific compound examples used for preparation of specific siloxane oligomer In the above synthesis method, specific compound examples of raw materials used for the synthesis of the specific siloxane oligomer according to the present invention are listed below, but the present invention is not limited thereto.
(A) Alkoxysilane compound (A-1) Si (OMe) ₄ , (A-2) Si (OEt) ₄ ,
(A-3) Si (OPr) ₄ , (A-4) Si (OBu) ₄ ,
(A-5) MeSi (OMe) ₃ , (A-6) MeSi (OEt) ₃ ,
(A-7) Me ₂ Si (OMe) ₂
(A-8) Me (EtO) ₂ Si—O—Si (OEt) ₂ Me
_{(A-9) CH 2 =} CHSi (OMe) 3
_{(A-10) CH 2 =} CHCH 2 Si (OMe) 3 , etc.

(B) a hydroxycarboxylic acid _{(B-1) HOCH 2 COOH} , (B-2) HOCH 2 CH 2 COOH,
(B-3) HOCH (Me) COOH, (B-4) HOC (Me) ₂ COOH,
_{(B-5) HOCH 2 CH} (Me) COOH,
(B-6) HOCH ₂ C (Me) ₂ COOH, etc.

(C) Substituent-containing alcohol (C-1) HOCH ₂ COOC ₂ H ₅ , (C-1) HOCH ₂ CH ₂ CN,
(C-2) HOCH ₂ CF ₂ CF ₂ H, (C-3) HOCH ₂ CF ₃ ,
_{(C-4) HOCH 2 CH} 2 F, (C-5) HOCH 2 CH 2 Si (CH 3) 3
(C-6) HOCH ₂ OCOCH ₂ CH═CH ₂ etc. Here, Me represents a methyl group, OMe represents a methoxy group, OEt represents an ethoxy group, OPr represents a propoxy group, OBu represents a butoxy group, respectively. Represent.

  As described above, the electrolytic solution of the present invention containing the specific siloxane oligomer is prepared. The thus obtained electrolyte for a non-aqueous secondary battery of the present invention can improve cycle characteristics.

(Organic solvent)
Examples of the organic solvent used in the present invention include ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, γ-butyrolactone, γ-valerolactone, 1,2-dimethoxyethane. , Tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, 1,3-dioxane, 1,4-dioxane, methyl acetate, ethyl acetate, methyl propionate, propion Ethyl acetate, methyl butyrate, methyl isobutyrate, methyl trimethyl acetate, ethyl trimethyl acetate, acetonitrile, glutaronitrile, adiponitrile, methoxyacetonitrile, 3-methoxypropionitrile, N, N-dimethylformamide, N-methylpi Examples include loridinone, N-methyloxazolidinone, N, N′-dimethylimidazolidinone, nitromethane, nitroethane, sulfolane, trimethyl phosphate, dimethyl sulfoxide, and dimethyl sulfoxide phosphoric acid. These may be used alone or in combination of two or more. Among them, at least one member selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate is preferable. Particularly, a high viscosity (high dielectric constant) solvent such as ethylene carbonate or propylene carbonate (for example, ratio A combination of a dielectric constant ε ≧ 30) and a low viscosity solvent such as dimethyl carbonate, ethyl methyl carbonate, or diethyl carbonate (for example, viscosity ≦ 1 mPa · s) is more preferable. This is because the dissociation property of the electrolyte salt and the ion mobility are improved.
However, the organic solvent (nonaqueous solvent) used in the present invention is not limited to the above examples.

  Moreover, the solvent may contain the cyclic carbonate which has an unsaturated bond. This is because the chemical stability of the electrolytic solution is further improved. Examples of the cyclic carbonate having an unsaturated bond include at least one selected from the group consisting of vinylene carbonate compounds, vinyl ethylene carbonate compounds and methylene ethylene carbonate compounds.

  Examples of the vinylene carbonate compound include vinylene carbonate (1,3-dioxol-2-one), methyl vinylene carbonate (4-methyl-1,3-dioxol-2-one), and ethyl vinylene carbonate (4-ethyl- 1,3-dioxol-2-one), 4,5-dimethyl-1,3-dioxol-2-one, 4,5-diethyl-1,3-dioxol-2-one, 4-fluoro-1,3 -Dioxol-2-one or 4-trifluoromethyl-1,3-dioxol-2-one and the like.

  Examples of the vinyl carbonate-based compound include vinyl ethylene carbonate (4-vinyl-1,3-dioxolan-2-one), 4-methyl-4-vinyl-1,3-dioxolan-2-one, and 4-ethyl. -4-vinyl-1,3-dioxolan-2-one, 4-n-propyl-4-vinyl-1,3-dioxolan-2-one, 5-methyl-4-vinyl-1,3-dioxolane-2 -One, 4,4-divinyl-1,3-dioxolan-2-one, 4,5-divinyl-1,3-dioxolan-2-one and the like.

  Examples of the methylene ethylene carbonate compound include 4-methylene-1,3-dioxolan-2-one, 4,4-dimethyl-5-methylene-1,3-dioxolan-2-one, and 4,4-diethyl-5-one. And methylene-1,3-dioxolan-2-one.

  These may be used alone or in combination of two or more. Among these, vinylene carbonate is preferable. This is because a high effect can be obtained.

(Group 1 or Group 2 ions, etc.)
The metal ions belonging to Group 1 or Group 2 of the periodic table contained in the electrolytic solution of the present invention or salts thereof are appropriately selected depending on the intended use of the electrolytic solution, for example, lithium salts, potassium salts, sodium salts, A calcium salt, a magnesium salt, etc. are mentioned, When using for a secondary battery etc., lithium salt is preferable from an output viewpoint. When the electrolytic solution of the present invention is used as an electrolyte of a non-aqueous electrolytic solution for a lithium secondary battery, a lithium salt may be selected as a metal ion salt. The lithium salt is not particularly limited as long as it is a lithium salt usually used for an electrolyte of a non-aqueous electrolyte solution for a lithium secondary battery. For example, those described below are preferable.

(L-1) Inorganic lithium salt: inorganic fluoride salt such as LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiSbF ₆ ; perhalogenate such as LiClO ₄ , LiBRO ₄ , LiIO ₄ ; inorganic chloride salt such as LiAlCl ₄ etc.

(L-2) Fluorine-containing organic lithium salt: Perfluoroalkane sulfonate such as LiCF ₃ SO ₃ ; LiN (CF ₃ SO ₂ ) ₂ , LiN (CF ₃ CF ₂ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , Perfluoroalkanesulfonylimide salts such as LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ ); perfluoroalkanesulfonylmethide salts such as LiC (CF ₃ SO ₂ ) ₃ ; Li [PF ₅ (CF ₂ CF ₂ CF ₃ )], Li [PF ₄ (CF ₂ CF ₂ CF ₃ ) ₂ ], Li [PF ₃ (CF ₂ CF ₂ CF ₃ ) ₃ ], Li [PF ₅ (CF ₂ CF ₂ CF ₂ CF _{3 )], Li [PF 4 (} CF 2 CF 2 CF 2 CF 3) 2], Li [PF 3 (CF 2 CF 2 CF 2 CF 3) 3] fluoroalkyl fluoride such as potash Acid salts, and the like.

  (L-3) Oxalatoborate salt: lithium bis (oxalato) borate, lithium difluorooxalatoborate and the like.

Among these, LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiSbF ₆ , LiClO ₄ , Li (Rf ¹ SO ₃ ), LiN (Rf ¹ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , and LiN (Rf ¹ SO ₂ ) (Rf ² SO ₂ ) ₂ is preferred, such as LiPF ₆ , LiBF ₄ , LiN (Rf ¹ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , and LiN (Rf ¹ SO ₂ ) (Rf ² SO ₂ ) ₂ The lithium imide salt is more preferable. Here, Rf ^{1 and} Rf ² each represent a perfluoroalkyl group.
In addition, the lithium salt used for electrolyte solution may be used individually by 1 type, or may combine 2 or more types arbitrarily.
The content of metal ions belonging to Group 1 or Group 2 of the periodic table in the electrolytic solution or a metal salt containing the metal ion is added in an amount so as to obtain a preferable salt concentration described in the method for preparing the electrolytic solution below. The salt concentration is appropriately selected depending on the intended use of the electrolytic solution, but is generally 10% to 50% by mass, more preferably 15% to 30% by mass, based on the total mass of the electrolytic solution. In addition, when evaluating as an ion density | concentration, what is necessary is just to calculate by salt conversion with the metal applied suitably.

[Method for preparing electrolytic solution]
Next, a typical method for adjusting the electrolytic solution of the present invention will be described by taking as an example a case where a lithium salt is used as a metal ion salt. The electrolytic solution of the present invention can be prepared by dissolving a specific siloxane oligomer compound, a lithium salt, and various additives that are optionally added in the non-aqueous electrolytic solution solvent.

  In the present invention, “non-water” means that water is not substantially contained, and a trace amount of water may be contained as long as the effects of the invention are not hindered. In view of obtaining good characteristics, the water content is preferably 200 or less, and more preferably 100 or less. Although there is no particular lower limit, it is practical that it is 10 ppm or more considering inevitable mixing.

  The lithium salt concentration in the prepared electrolyte solution has an appropriate concentration range for showing high ionic conductivity because the viscosity of the electrolyte solution increases as the concentration increases. A preferable concentration range is 10% by mass to 50% by mass, and more preferably 15% by mass to 30% by mass, based on the total mass of the electrolytic solution. The viscosity of the electrolytic solution of the present invention is not particularly limited, but is preferably 10 to 0.1 mPa · s, and more preferably 5 to 0.5 mPa · s.

[Lithium secondary battery]
A preferred embodiment of the lithium ion secondary battery of the present invention will be described with reference to FIG. The lithium ion secondary battery 10 of this embodiment includes the electrolyte solution 5 for a non-aqueous secondary battery of the present invention and a positive electrode C capable of inserting and releasing lithium ions (a positive electrode current collector 1 and a positive electrode active material layer 2). And a negative electrode A (negative electrode current collector 3, negative electrode active material layer 4) capable of inserting and releasing lithium ions or dissolving and depositing lithium ions. In addition to these essential members, considering the purpose of use of the battery, the shape of the potential, etc., a separator 9 disposed between the positive electrode and the negative electrode, a current collecting terminal (not shown), an outer case, etc. (Not shown). If necessary, a protective element may be attached to at least one of the inside of the battery and the outside of the battery. By adopting such a structure, lithium ion transfer a and b occurs in the electrolytic solution 5, charging α and discharging β can be performed, and operation or power storage is performed via the operation mechanism 6 via the circuit wiring 7. It can be performed. Hereinafter, the configuration of the lithium secondary battery of the present invention will be described in detail.

(Battery shape)
The battery shape to which the lithium secondary battery of the present embodiment is applied is not particularly limited, and examples thereof include a bottomed cylindrical shape, a bottomed square shape, a thin shape, a sheet shape, and a paper shape. Any of these may be used. Further, it may be of a different shape such as a horseshoe shape or a comb shape considering the shape of the system or device to be incorporated. Among them, from the viewpoint of efficiently releasing the heat inside the battery to the outside, a square shape such as a bottomed square shape or a thin shape having at least one surface that is relatively flat and has a large area is preferable.

  In a battery having a bottomed cylindrical shape, since the outer surface area with respect to the power generating element to be filled becomes small, it is preferable to design so that Joule heat generated by the internal resistance at the time of charging and discharging efficiently escapes to the outside. Moreover, it is preferable to design so that the filling ratio of the substance having high thermal conductivity is increased and the temperature distribution inside is reduced.

In the bottomed square shape, the ratio of the area S of the largest surface (the product of the width and height of the outer dimensions excluding the terminal portion, unit cm ² ) to the thickness T (unit cm) of the battery outer shape The 2S / T value is preferably 100 or more, and more preferably 200 or more. By increasing the maximum surface, it is possible to improve characteristics such as cycle performance and high-temperature storage even for high-power and large-capacity batteries, and increase the heat dissipation efficiency during abnormal heat generation. It is possible to suppress a dangerous state of “rupture”.

(Members constituting the battery)
The lithium secondary battery according to this embodiment includes an electrolytic solution 5, positive electrode and negative electrode electrode mixtures C and A, and a separator basic member 9. Hereinafter, each of these members will be described. The lithium secondary battery of the present invention includes at least the electrolyte solution for a non-aqueous battery of the present invention as an electrolytic solution.

(Electrolyte)
The electrolyte used for the lithium secondary battery of this embodiment is a non-aqueous electrolyte solvent, a non-aqueous electrolyte solvent containing at least a specific silicon compound and a lithium salt as an electrolyte salt, prepared by the method described above. It is preferable to contain the electrolyte solution for water secondary batteries as a main component. That is, the electrolytic solution 5 is preferably a nonaqueous secondary battery electrolytic solution containing the specific silicon compound as a nonaqueous electrolytic solution and a lithium salt as an electrolyte salt. The electrolyte salt used in the electrolyte for a non-aqueous secondary battery is a salt of a metal ion belonging to Group 1 or Group 2 of the periodic table, and the electrolyte for a non-aqueous secondary battery of the present invention. Those described in detail in the embodiment can be used. Similarly, as the non-aqueous electrolyte solvent used in the lithium secondary battery of the present invention, those described in detail in the embodiment of the electrolyte for non-aqueous secondary battery of the present invention can be used. Furthermore, other additives can be added to further improve the performance.

  In the electrolytic solution according to the present invention, various additives can be used depending on the purpose as long as the effects of the present invention are not impaired in order to improve battery performance. As such an additive, such a functional additive such as an overcharge inhibitor, a negative electrode film forming agent, a positive electrode protective agent; and the like may be used.

  Moreover, the combined use of a negative electrode film forming agent and a positive electrode protective agent, or the combined use of an overcharge inhibitor, a negative electrode film forming agent, and a positive electrode protective agent is particularly preferable.

  The content ratio of these functional additives in the non-aqueous electrolyte solution is not particularly limited, but is preferably 0.01% by mass or more, particularly preferably 0.1% by mass or more, respectively, with respect to the entire non-aqueous electrolyte solution. More preferably, it is 0.2% by mass or more, and the upper limit is preferably 5% by mass or less, particularly preferably 3% by mass or less, and further preferably 2% by mass or less. By adding these compounds, it is possible to suppress rupture / ignition of the battery at the time of abnormality due to overcharge, and to improve the capacity maintenance characteristic and cycle characteristic after high-temperature storage.

(Electrode mixture)
The electrode mixture is obtained by applying a dispersion of an active material and a conductive agent, a binder, a filler, etc. on a current collector (electrode base material). In a lithium battery, the active material is a positive electrode active material. A negative electrode mixture in which the positive electrode mixture and the active material are negative electrode active materials is used. Next, the positive electrode active material, the negative electrode active material, the conductive agent, the binder, the filler, and the current collector that constitute the electrode mixture will be described.
-Positive electrode active material You may use a particulate-form positive electrode active material for the electrolyte solution for non-aqueous secondary batteries of this invention. As the positive electrode active material used in the present invention, a transition metal oxide capable of reversibly inserting and releasing lithium ions can be used, but a lithium-containing transition metal oxide is preferably used. In the present invention, preferred examples of the lithium-containing transition metal oxide preferably used as the positive electrode active material include oxides containing lithium, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, and W. It is done. Alkali metals other than lithium (elements of Group 1 (Ia) and Group 2 (IIa) of the periodic table) and / or Al, Ga, In, Ge, Sn, Pb, Sb, Bi, Si, P , B, etc. may be mixed. The mixing amount is preferably 0 to 30 mol% with respect to the transition metal.

  Among the lithium-containing transition metal oxides preferably used as the positive electrode active material, a lithium compound / transition metal compound (wherein the transition metal is selected from Ti, V, Cr, Mn, Fe, Co, Ni, Mo, W) It is more preferable that the mixture is synthesized so that the total molar ratio of the compound is 0.3 to 2.2.

Further, among the lithium compounds / transition metal compounds, Li _g M3O ₂ (M3 represents one or more elements selected from Co, Ni, Fe, and Mn. G represents 0 to 1.2. ) Or a material having a spinel structure represented by Li _h M4 ₂ O (M4 represents Mn. H represents 0 to 2). As M3 and M4, Al, Ga, In, Ge, Sn, Pb, Sb, Bi, Si, P, and B may be mixed in addition to the transition metal. The mixing amount is preferably 0 to 30 mol% with respect to the transition metal.

The _Li g M3O material containing _2, among the materials having the spinel structure represented by _{Li h M4 2 O, Li g} CoO 2, Li g NiO 2, Li g MnO 2, Li g Co j Ni 1-j O _{2, Li h Mn 2 O 4} , LiNi j Mn 1-j O 2, LiCo j Ni h Al 1-j-h O 2, LiCo j Ni h Mn 1-j-h O 2, LiMn h Al 2-h O ₄ , LiMn _h Ni _{2 -h} O ₄ (where g represents 0.02 to 1.2, j represents 0.1 to 0.9, and h represents 0 to 2) is particularly preferable. . Here, the g value and the h value are values before the start of charge / discharge, and are values that increase / decrease due to charge / discharge. In particular,
LiNi _0.5 Mn _0.5 O ₂ , LiNi _0.85 Co _0.01 Al _0.05 O ₂ ,
LiNi _0.33 Co _0.33 Mn _0.33 O ₂ , LiMn _1.8 Al _0.2 O ₄ ,
LiMn _1.5 Ni _0.5 O ₄ and the like.

As the transition metal of the lithium-containing transition metal phosphate compound, V, Ti, Cr, Mn, Fe, Co, Ni, Cu and the like are preferable, and specific examples include, for example, LiFePO ₄ , Li ₃ Fe ₂ (PO ₄ ). ₃ , iron phosphates such as LiFeP ₂ O ₇ , cobalt phosphates such as LiCoPO ₄ , and some of the transition metal atoms that are the main components of these lithium transition metal phosphate compounds are Al, Ti, V, Cr, Mn , Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Nb, Si and the like substituted with other metals.

In the nonaqueous electrolyte secondary battery of the present invention, the average particle size of the positive electrode active material used is not particularly limited, but is preferably 0.1 μm to 50 μm. No particular limitation is imposed on the specific surface area, preferably from 0.01m ² / g~50m ² / g by the BET method. Further, the pH of the supernatant when 5 g of the positive electrode active material is dissolved in 100 ml of distilled water is preferably 7 or more and 12 or less.

  In order to make the positive electrode active substance have a predetermined particle size, a well-known pulverizer or classifier is used. For example, a mortar, a ball mill, a vibration ball mill, a vibration mill, a satellite ball mill, a planetary ball mill, a swirling air flow type jet mill, a sieve, or the like is used. The positive electrode active material obtained by the firing method may be used after being washed with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent.

(Negative electrode active material)
The negative electrode active material used in the electrolyte solution for a non-aqueous secondary battery of the present invention is not particularly limited as long as it can reversibly insert and release lithium ions. Carbonaceous materials, tin oxide, silicon oxide, etc. Metal oxides, metal composite oxides, lithium alloys such as lithium alone and lithium aluminum alloys, and metals that can form alloys with lithium such as Sn and Si.
These may be used individually by 1 type, or may use 2 or more types together by arbitrary combinations and a ratio. Of these, carbonaceous materials or lithium composite oxides are preferably used from the viewpoint of safety.
Further, the metal composite oxide is not particularly limited as long as it can occlude and release lithium, but it preferably contains titanium and / or lithium as a constituent component from the viewpoint of high current density charge / discharge characteristics. .

  The carbonaceous material used as the negative electrode active material is a material substantially made of carbon. Examples thereof include carbonaceous materials obtained by baking various synthetic resins such as artificial pitches such as petroleum pitch, natural graphite, and vapor-grown graphite, and PAN-based resins and furfuryl alcohol resins. Furthermore, various carbon fibers such as PAN-based carbon fiber, cellulose-based carbon fiber, pitch-based carbon fiber, vapor-grown carbon fiber, dehydrated PVA-based carbon fiber, lignin carbon fiber, glassy carbon fiber, activated carbon fiber, mesophase micro Examples thereof include spheres, graphite whiskers, and flat graphite.

  These carbonaceous materials can be divided into non-graphitizable carbon materials and graphite-based carbon materials depending on the degree of graphitization. Further, the carbonaceous material preferably has the surface spacing, density, and crystallite size described in JP-A-62-222066, JP-A-2-6856, and 3-45473. The carbonaceous material does not need to be a single material, and a mixture of natural graphite and artificial graphite described in JP-A-5-90844, graphite having a coating layer described in JP-A-6-4516, or the like is used. You can also.

  The metal oxide and metal composite oxide, which are negative electrode active materials used in the lithium secondary battery of the present invention, need only contain at least one of them. As the metal oxide and metal complex oxide, amorphous oxide is particularly preferable, and chalcogenite, which is a reaction product of a metal element and an element of Group 16 of the periodic table, is also preferably used. The term “amorphous” as used herein means an X-ray diffraction method using CuKα rays, which has a broad scattering band having an apex in the region of 20 ° to 40 ° in terms of 2θ values, and is a crystalline diffraction line. You may have. The strongest intensity of crystalline diffraction lines seen from 2 ° to 40 ° to 70 ° is 100 times the diffraction line intensity at the peak of the broad scattering band seen from 2 ° to 20 °. It is preferable that it is 5 times or less, and it is particularly preferable not to have a crystalline diffraction line.

Among the compound group consisting of the amorphous oxide and the chalcogenide, an amorphous oxide of a metalloid element and a chalcogenide are more preferable, and elements of Groups 13 (IIIB) to 15 (VB) of the periodic table, Particularly preferred are oxides and chalcogenides composed of one kind of Al, Ga, Si, Sn, Ge, Pb, Sb, Bi or a combination of two or more kinds thereof. Specific examples of preferable amorphous oxides and chalcogenides include, for example, Ga ₂ O ₃ , SiO, GeO, SnO, SnO ₂ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₂ O ₄ , Pb ₃ O ₄ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , Bi ₂ O ₃ , Bi ₂ O ₄ , SnSiO ₃ , GeS, SnS, SnS ₂ , PbS, PbS ₂ , Sb ₂ S ₃ , Sb ₂ S ₅ , such as SnSiS ₃ may preferably be mentioned. Moreover, these may be a complex oxide with lithium oxide, for example, Li ₂ SnO ₂ .

  In the nonaqueous electrolyte secondary battery of the present invention, the average particle size of the negative electrode active material used is preferably 0.1 μm to 60 μm. To obtain a predetermined particle size, a well-known pulverizer or classifier is used. For example, a mortar, a ball mill, a sand mill, a vibrating ball mill, a satellite ball mill, a planetary ball mill, a swirling air flow type jet mill or a sieve is preferably used. When pulverizing, wet pulverization in the presence of water or an organic solvent such as methanol can be performed as necessary. In order to obtain a desired particle size, classification is preferably performed. The classification method is not particularly limited, and a sieve, an air classifier, or the like can be used as necessary. Classification can be used both dry and wet.

  The chemical formula of the compound obtained by the firing method can be calculated from an inductively coupled plasma (ICP) emission spectroscopic analysis method as a measurement method and a mass difference between powders before and after firing as a simple method.

  In the present invention, as the negative electrode active material that can be used in combination with the amorphous oxide negative electrode active material centering on Sn, Si, Ge, a carbon material capable of inserting and extracting lithium ions or lithium metal, lithium, Preferred examples include lithium alloys and metals that can be alloyed with lithium.

(Conductive material)
Any conductive material may be used as long as it is an electron conductive material that does not cause a chemical change in the constructed secondary battery, and any known conductive material can be used. Usually, natural graphite (scale-like graphite, scale-like graphite, earth-like graphite, etc.), artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber and metal powder (copper, nickel, aluminum, silver (Japanese Patent Laid-Open No. Sho 63- 10148,554)), metal fibers or polyphenylene derivatives (described in JP-A-59-20971) can be contained as a single type or a mixture thereof. Among these, the combined use of graphite and acetylene black is particularly preferable. As addition amount of the said electrically conductive agent, 1-50 mass% is preferable and 2-30 mass% is more preferable. In the case of carbon or graphite, 2 to 15% by mass is particularly preferable.

(Binder)
In this invention, the binder for hold | maintaining the said electrode mixture is used.
Examples of the binder include polysaccharides, thermoplastic resin 20 and polymers having rubber elasticity. Among them, for example, starch, carboxymethylcellulose, cellulose, diacetylcellulose, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, alginic acid. Water-soluble polymers such as sodium, polyacrylic acid, sodium polyacrylate, polyvinyl phenol, polyvinyl methyl ether, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylonitrile, polyacrylamide, polyhydroxy (meth) acrylate, styrene-maleic acid copolymer, Polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, vinylide (Meth) acrylic such as fluoride-tetrafluoroethylene-hexafluoropropylene copolymer, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, polyvinyl acetal resin, methyl methacrylate, 2-ethylhexyl acrylate (Meth) acrylic acid ester copolymer containing acid ester, (meth) acrylic acid ester-acrylonitrile copolymer, polyvinyl ester copolymer containing vinyl ester such as vinyl acetate, styrene-butadiene copolymer, acrylonitrile -Butadiene copolymer, polybutadiene, neoprene rubber, fluoro rubber, polyethylene oxide, polyester polyurethane resin, polyether polyurethane resin, polycarbonate polymer Urethane resins, polyester resins, phenolic resins, emulsion (latex) or a suspension such as an epoxy resin is preferable, a latex of polyacrylate, carboxymethyl cellulose, polytetrafluoroethylene, polyvinylidene fluoride is more preferable.

  A binder can be used individually by 1 type or in mixture of 2 or more types. When the amount of the binder added is small, the holding power and cohesive force of the electrode mixture are weakened. If the amount is too large, the electrode volume increases and the capacity per electrode unit volume or unit mass decreases. For this reason, the addition amount of the binder is preferably 1 to 30% by mass, and more preferably 2 to 10% by mass.

(Filler)
The electrolytic solution of the present invention may contain a filler. As the material for forming the filler, any fibrous material that does not cause a chemical change in the secondary battery of the present invention can be used. Usually, fibrous fillers made of materials such as olefin polymers such as polypropylene and polyethylene, glass, and carbon are used. Although the addition amount of a filler is not specifically limited, 0-30 mass% is preferable.

(Current collector)
As the positive / negative current collector, an electronic conductor that does not cause a chemical change in the nonaqueous electrolyte secondary battery of the present invention is used. As the current collector of the positive electrode, in addition to aluminum, stainless steel, nickel, titanium, etc., the surface of aluminum or stainless steel is preferably treated with carbon, nickel, titanium, or silver. Among them, aluminum and aluminum alloys are preferable. More preferred.

  As the negative electrode current collector, copper, stainless steel, nickel, and titanium are preferable, and copper or a copper alloy is more preferable.

As the shape of the current collector, a film sheet shape is usually used, but a net, a punched material, a lath body, a porous body, a foamed body, a molded body of a fiber group, and the like can also be used. The thickness of the current collector is not particularly limited, but is preferably 1 μm to 500 μm. Moreover, it is also preferable that the current collector surface is roughened by surface treatment.
An electrode mixture for a lithium secondary battery is formed by a member appropriately selected from these materials.

(Separator)
The separator used in the lithium secondary battery of the present invention is particularly limited as long as it is a material that mechanically insulates the positive electrode and the negative electrode, has ion permeability, and has oxidation / reduction resistance at the contact surface between the positive electrode and the negative electrode. It will never be done. As such a material, a porous polymer material, an inorganic material, an organic-inorganic hybrid material, glass fiber, or the like is used. These separators preferably have a shutdown function for ensuring safety, that is, a function of closing the gap at 80 ° C. or higher to increase resistance and interrupting current, and the closing temperature is 90 ° C. or higher and 180 ° C. or lower. Preferably there is.

  The shape of the hole of the separator is usually circular or elliptical, and the size is 0.05 μm to 30 μm, preferably 0.1 μm to 20 μm. Furthermore, it may be a rod-like or irregular-shaped hole as in the case of making by a stretching method or a phase separation method. The ratio of these gaps, that is, the porosity, is 20% to 90%, preferably 35% to 80%.

  The polymer material may be a single material such as polyethylene or polypropylene, or may be a material using two or more composite materials. What laminated | stacked the 2 or more types of microporous film which changed the hole diameter, the porosity, the obstruction | occlusion temperature of a hole, etc. is preferable.

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

(Preparation of non-aqueous electrolyte secondary battery)
As described above, the lithium secondary battery of the present invention can be applied to any shape such as a sheet shape, a square shape, and a cylinder shape. A positive electrode active material or a mixture of negative electrode active materials is mainly used after being applied (coated), dried and compressed on a current collector.

  Hereinafter, with reference to FIG. 2, a configuration and a manufacturing method thereof will be described using the bottomed cylindrical lithium secondary battery 100 as an example. FIG. 2 is a schematic cross-sectional view showing an example of the bottomed cylindrical lithium secondary battery 100 in which the positive electrode sheet 14 and the negative electrode sheet 16 that are stacked with the separator 12 interposed therebetween are wound and stored in the outer can 18.

  First, a negative electrode active material is mixed with a binder or filler used as desired in an organic solvent to prepare a slurry-like or paste-like negative electrode mixture. The obtained negative electrode mixture is uniformly applied over the entire surface of both surfaces of the metal core as a current collector, and then the organic solvent is removed to form a negative electrode mixture layer. Further, the laminate of the current collector and the negative electrode mixture layer is rolled with a roll press or the like to prepare a predetermined thickness to obtain a negative electrode sheet (electrode sheet) 16. At this time, the coating method of the nucleating agent, the drying of the coated material, and the method of forming the positive and negative electrodes may be according to conventional methods.

  In the present embodiment, a cylindrical battery is taken as an example, but the present invention is not limited to this, for example, after the positive and negative electrode sheets produced by the above method are overlapped via a separator, After processing into a sheet battery as it is, or inserting it into a rectangular can after being folded and electrically connecting the can and the sheet, injecting an electrolyte and sealing the opening using a sealing plate A square battery may be formed.

  In any embodiment, the safety valve can be used as a sealing plate for sealing the opening. In addition to the safety valve, the sealing member may be provided with various conventionally known safety elements. For example, a fuse, bimetal, PTC element, or the like is preferably used as the overcurrent prevention element.

  In addition to the safety valve, as a countermeasure against the increase in the internal pressure of the battery can, a method of cutting the battery can, a method of cracking the gasket, a method of cracking the sealing plate, or a method of cutting the lead plate can be used. Further, the charger may be provided with a protection circuit incorporating measures against overcharge and overdischarge, or may be connected independently.

  For the can and lead plate, a metal or alloy having electrical conductivity can be used. For example, metals such as iron, nickel, titanium, chromium, molybdenum, copper, and aluminum, or alloys thereof are preferably used.

  As a method for welding the cap, the can, the sheet, and the lead plate, a known method (eg, direct current or alternating current electric welding, laser welding, ultrasonic welding) can be used. As the sealing agent for sealing, a conventionally known compound or mixture such as asphalt can be used.

[Use of lithium secondary battery of the present invention]
The secondary battery of the present invention can be applied to various applications because a secondary battery with good cycleability can be produced by adding a specific silicon compound.
Although there is no particular limitation on the application mode, for example, when installed in an electronic device, a notebook computer, a pen input personal computer, a mobile personal computer, an electronic book player, a mobile phone, a cordless phone, a pager, a handy terminal, a mobile fax, a mobile phone Copy, portable printer, headphone stereo, video movie, LCD TV, handy cleaner, portable CD, minidisc, electric shaver, transceiver, electronic notebook, calculator, memory card, portable tape recorder, radio, backup power supply, memory card, etc. It is done. Other consumer products include automobiles, electric vehicles, motors, lighting equipment, toys, game equipment, road conditioners, watches, strobes, cameras, medical equipment (such as pacemakers, hearing aids, and shoulder grinders). Furthermore, it can be used for various military use and space use. Moreover, it can also combine with a solar cell.

  Although the metal ion used for charge transport in the secondary battery of the present invention is not particularly limited, it is preferable to use a metal ion belonging to Group 1 or Group 2 of the periodic table. Among these, it is preferable to use lithium ions, sodium ions, magnesium ions, calcium ions, aluminum ions, and the like. There are many documents and books such as the patent documents listed at the beginning for general technical matters regarding secondary batteries using lithium ions, which are helpful. In addition, regarding the secondary battery using sodium ion, Journal of Electrochemical Society; Electrochemical Science and Technology, USA, 1980, Vol. 127, pages 2097-2099, and the like can be referred to. For magnesium ions, see Nature 407, p. 724-727 (2000) and the like can be referred to. For calcium ions, see J.H. Electrochem. Soc. , Vol. 138, 3536 (1991) and the like. In the present invention, it is preferable to apply to a lithium ion secondary battery because of its widespread use, but the other effects also have a desired effect and should not be construed as being limited thereto.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

[Preparation of electrolyte for non-aqueous secondary battery]
・ Synthesis of specific silicon compounds

(Synthesis Example 1: Synthesis of specific silicon oligomer compound (Si-1))
50.0 g of methyltriethoxysilane and 7.65 g of glycolic acid were mixed and heated to reflux at 150 ° C. for 1 hour. After the reaction, the temperature was maintained at 150 ° C., and the volatile components were distilled off while gradually reducing the degree of vacuum from normal pressure to 5 mmHg to obtain 16 g of a specific siloxane oligomer (Si-1) as a colorless liquid. The number average molecular weight in terms of styrene as measured by GPC was 1,200. Moreover, the content mole fraction of the substituent corresponding to the substituent —O—Q ¹ —COOR ³ contained in the partial structure represented by the general formula (1) measured by H ¹ -NMR is 32 mol%. The branched mole fraction (xc + xd + xe) as measured by Si-NMR was 25 mol%.

(Synthesis Example 2: Synthesis of specific silicon oligomer compound (Si-2))
50 g of methyltetraethylsilane, 7.65 g of glycolic acid, and 24.2 g of ethyl glycolate were mixed and heated to reflux at 150 ° C. for 1 hour. After the reaction, the temperature was maintained at 150 ° C., and the volatile component was distilled off while gradually decreasing the vacuum from normal pressure to 5 mmHg, to obtain 18 g of a specific siloxane oligomer (Si-2) as a colorless liquid. The number average molecular weight in terms of styrene by GPC measurement is 1,500, and the content mole of the substituent —OQ ¹ —COOR ³ contained in the partial structure represented by the general formula (1) measured by H ¹ -NMR The fraction was 41 mol%, and the branched molar fraction (xc + xd + xe) as measured by Si-NMR was 20 mol%.

(Synthesis Example 3: Synthesis of specific silicon oligomer compound (Si-3))
Tetraethoxysilane 50.0 g and glycolic acid 18.6 g were mixed and heated to reflux at 150 ° C. for 1 hour. After the reaction, the temperature was maintained at 150 ° C., and the volatile component was distilled off while gradually decreasing the degree of vacuum from normal pressure to 5 mmHg to obtain 42.7 g of a specific siloxane oligomer (Si-3) as a colorless liquid. The number average molecular weight in terms of styrene by GPC measurement is 1,450, and the content mole of the substituent —OQ ¹ —COOR ³ contained in the partial structure represented by the general formula (1) measured by H ¹ -NMR The fraction was 52 mol%, and the branched molar fraction (xc + xd + xe) was 23 mol% by Si-NMR measurement.

(Synthesis Example 4: Synthesis of specific silicon oligomer compound (Si-4))
42.2 g of tetramethoxysilane, 57.8 g of tetraethoxysilane and 16 g of glycolic acid were mixed and heated to reflux at 150 ° C. for 1 hour. After the reaction, the temperature was maintained at 150 ° C., and the volatile components were distilled off while gradually decreasing the degree of vacuum from normal pressure to 5 mmHg to obtain 76.2 g of a specific siloxane oligomer (Si-4) as a colorless liquid. The number average molecular weight in terms of styrene by GPC measurement is 780, and the mole fraction of the substituent —OQ ¹ —COOR ³ contained in the partial structure represented by the general formula (1), measured by H ¹ -NMR. Was 42 mol%, and the branched mole fraction (xc + xd + xe) was 10% by Si-NMR measurement.

(Synthesis Example 5: Synthesis of specific silicon oligomer compound (Si-5))
50.0 g of methyltriethoxysilane, 12.8 g of glycolic acid, and 1.99 g of ethylene cyanohydrin were mixed and heated to reflux at 150 ° C. for 1 hour. After the reaction, the temperature was maintained at 150 ° C., and the volatile components were distilled off while gradually decreasing the degree of vacuum from normal pressure to 5 mmHg to obtain 29.7 g of a specific siloxane oligomer (Si-5) as a colorless liquid. The number average molecular weight in terms of styrene by GPC measurement is 1,200, and the content mole of the substituent —OQ ¹ —COOR ³ contained in the partial structure represented by the general formula (1), measured by H ¹ -NMR. The fraction was 25 mol%, and the branched molar fraction (xc + xd + xe) was 19% according to Si-NMR measurement.

(Synthesis Example 6: Synthesis of specific silicon oligomer compound (Si-6))
Tetramethoxysilane 50.0 g, glycolic acid 15 g, 2,2,3,3-tetrafluoro-1-propanol 19.7 g were mixed and heated to reflux at 150 ° C. for 1 hour. After the reaction, the temperature was maintained at 150 ° C., and the volatile component was distilled off while gradually decreasing the degree of vacuum from normal pressure to 5 mmHg to obtain 42.2 g of a specific siloxane oligomer (Si-6) as a colorless liquid. The number average molecular weight in terms of styrene by GPC measurement is 1,400, and the content mole of the substituent —OQ ¹ —COOR ³ contained in the partial structure represented by the general formula (1), measured by H ¹ -NMR. The fraction was 38 mol%, and the branched mol fraction (xc + xd + xe) was 18 mol% by Si-NMR measurement.

(Synthesis Example 7: Synthesis of specific silicon oligomer compound (Si-7))
40.0 g of tetraethoxysilane, 10.4 g of 2-cyanoethyltriethoxysilane, and 6.57 g of glycolic acid were mixed and heated to reflux at 150 ° C. for 1 hour. After the reaction, the temperature was kept at 150 ° C., and the volatile components were distilled off while gradually decreasing the degree of vacuum from normal pressure to 5 mmHg to obtain 33.9 g of a specific siloxane oligomer (Si-7) as a colorless liquid. The number average molecular weight in terms of styrene by GPC measurement is 820, and the content mole fraction of the substituent —OQ ¹ —COOR ³ contained in the partial structure represented by the general formula (1) measured by H ¹ -NMR. Was 36 mol%, and the branching mole fraction (xc + xd + xe) was 13 mol% by Si-NMR measurement.

(Synthesis Example 8: Synthesis of specific silicon oligomer compound (Si-8))
29.6 g of trimethoxyvinylsilane, 30.4 g of tetramethoxysilane, and 15.2 g of glycolic acid were mixed and heated to reflux at 150 ° C. for 1 hour. After the reaction, the temperature was maintained at 150 ° C., and the volatile components were distilled off while gradually decreasing the degree of vacuum from normal pressure to 5 mmHg to obtain 29.1 g of a specific siloxane oligomer (Si-8) as a colorless liquid. The number average molecular weight in terms of styrene by GPC measurement was 1,210. Moreover, the content mole fraction of the substituent corresponding to the substituent —O—Q ¹ —COOR ³ contained in the partial structure represented by the general formula (1) measured by H ¹ -NMR is 32 mol%. The branched mole fraction (xc + xd + xe) as measured by Si-NMR was 22 mol%.

(Synthesis Example 9: Synthesis of specific silicon oligomer compound (Si-9))
24 g of trimethoxyallylsilane, 22.5 g of tetramethoxysilane and 11.25 g of glycolic acid were mixed and heated to reflux at 150 ° C. for 1 hour. After the reaction, the temperature was maintained at 150 ° C., and the volatile component was distilled off while gradually decreasing the degree of vacuum from normal pressure to 5 mmHg to obtain 18.9 g of a specific siloxane oligomer (Si-9) as a colorless liquid. The number average molecular weight in terms of styrene as measured by GPC was 1,250. Moreover, the content mole fraction of the substituent corresponding to the substituent —OQ ¹ —COOR ³ contained in the partial structure represented by the general formula (1) measured by H ¹ -NMR is 28 mol%. The branched mole fraction (xc + xd + xe) as measured by Si-NMR was 24 mol%.

(Synthesis Example 10)
The following compounds were synthesized based on the description of Examples and Comparative Examples in JP-A-2007-89735.

<Examples and comparative examples>
2. Preparation of Electrolyte 1M LiPF ₆ ethylene carbonate / diethyl carbonate volume ratio 1: 1 to 1 and volume ratio 1 to 3 in the electrolyte, the silicon compounds shown in Table 1 below were used in the concentration (mass %) To prepare each electrolyte sample. In addition, the sample described as "-" in the column of a silicon compound has shown that the silicon compound is not added. The comparative examples used were vinylene carbonate (VC), tetramethoxysilane (R-1), vinyltrimethoxysilane (R-2), and cyclic carbonate-containing silicon compound (R-3) having the following structural formula. Is as follows. In addition, the evaluation result of each item was divided into high temperature cycle property (Table 2), low temperature discharge rate (Table 3), and capacity remaining rate (Table 4). Comparative compound R-3 is described in Japanese Patent Application Laid-Open No. 2007-077705.

[Lithium secondary battery]
Lithium cobaltate mixture sheet (electrode capacity 3.0 mAh / cm ² : aluminum foil base, 13 mmφ) on the positive electrode, natural spherical graphite electrode sheet (electrode capacity 3.2 mAh / cm2: Cu foil base, 14.5 mmφ) on the negative electrode, Using a PP porous film (thickness 25 μm, 16 mmφ) as a separator, a lithium secondary battery for evaluation using an electrolytic solution shown in Table 2 below was produced.

<High temperature cycle evaluation>
Using a 2032 type battery produced by the above method, charging at 1 C constant current in a thermostatic bath at 60 ° C. until the battery voltage becomes 4.2 V at 4.0 mA, the current value becomes 0.2 V at 4.2 V constant voltage. The battery was charged at 12 mA or 2 hours, and then at a current of 4.0 mA, 1 C constant current discharge was performed until the battery voltage reached 2.75 V, which was one cycle. This was repeated until 100 cycles were reached.

<Low-temperature discharge rate evaluation>
The discharge capacity ratio at −20 ° C. with respect to 30 ° C. was measured using the 2032 type battery produced by the above method. In a 30 ° C constant temperature bath, charge at 0.1 C constant current until the battery voltage reaches 4.2 V at 0.4 mA, then charge at 0.1 V mA at 4.2 V constant voltage, or charge for 2 hours Then, 0.1 C constant current discharge was performed in a thermostatic bath at −20 ° C. until the battery voltage reached 2.75 V at 0.4 mA, and the discharge capacity was measured.

<Self-discharge characteristic evaluation>
Using the 2032 type battery produced by the above method, after charging at a constant current of 0.1 C until the battery voltage becomes 4.2 V at 0.4 mA in an environment of 30 ° C., the current value is 4.2 V constant voltage. The battery was charged at 0.12 mA or 2 hours, 0.1 C constant current discharge was performed at 0.4 mA until the battery voltage reached 2.75 V, and the initial discharge capacity was measured. Furthermore, after charging at a constant current of 0.1 C until the battery voltage reaches 4.2 V at 0.4 mA, the current value becomes 0.12 mA at a constant voltage of 4.2 V, or after charging for 2 hours, It was left for 30 days in an environment of 45 ° C. Then, after taking out to 30 degreeC environment, the discharge capacity when discharging on the same discharge conditions was measured.

  As shown in Table 1, in the 2032 type nonaqueous electrolyte secondary battery of the example (samples 101 to 113), 100 cycles compared to the 2032 type nonaqueous electrolyte secondary battery of the comparative example (samples c11 to c17). It was confirmed that the eye capacity retention rate was excellent. As a result, in the electrode according to the battery of the example, a good SEI (Solid Electrolyte Interface) film was formed on the electrode surface by the action of the specific silicon compound added to the electrolytic solution, and the decomposition of the electrolytic solution was suppressed. It is thought that it is caused. It is estimated that SEI formed with a specific silicon compound is stable without causing a decomposition reaction such as decarboxylation that proceeds with a carbonate-based compound under high temperature and high voltage.

  As shown in Table 2, the 2032 type nonaqueous electrolyte secondary battery of Example 1 (samples 201 to 206) has a lower temperature than the 2032 type nonaqueous electrolyte secondary battery of the comparative example (samples c21 to c25). It was confirmed that the discharge rate was excellent. This result shows that the Tg of the SEI film formed on the electrode surface according to the battery of the example is lower than the film formed on the electrode surface according to the battery of the comparative example, and the lithium ion conductivity in the film at low temperature is high. It is presumed to be caused by that.

表３に示すように、実施例（試料３０１〜３０６）の２０３２形非水電解液二次電池では、比較例（試料ｃ３１〜３５）の２０３２形非水電解液二次電池よりも、自己放電特性が優れていることが確認された。この結果は、実施例の電池にかかる電極表面において、形成された被膜により電解液の分解が抑制されたことに起因すると推定している。また、正極表面において、形成された被膜により正極が安定化され、正極の自己分解を抑制したことに起因すると推定している。

As shown in Table 3, the 2032 type nonaqueous electrolyte secondary battery of the example (samples 301 to 306) is more self-discharged than the 2032 type nonaqueous electrolyte secondary battery of the comparative example (samples c31 to 35). It was confirmed that the characteristics were excellent. This result is presumed to be caused by the fact that decomposition of the electrolytic solution was suppressed by the formed film on the electrode surface of the battery of the example. Further, it is presumed that the positive electrode is stabilized on the surface of the positive electrode by the formed film and the self-decomposition of the positive electrode is suppressed.

DESCRIPTION OF SYMBOLS 1 Positive electrode conductive material 2 Positive electrode active material 3 Negative electrode conductive material 4 Negative electrode active material 5 Electrolyte 6 Operation means 7 Wiring 10 Lithium ion secondary battery 12 Separator 14 Positive electrode sheet 16 Negative electrode sheet 18 The outer can 20 which also serves as a negative electrode Insulating plate 22 Sealing plate 24 Cathode current collector 26 Gasket 28 Pressure sensitive valve element 30 Current interrupting element 100 Bottomed cylindrical lithium secondary battery

Claims (10)

A metal ion belonging to Group 1 or Group 2 of the periodic table or a salt thereof, and 0.005 to 10% by mass of a siloxane oligomer containing a partial structure represented by the following general formula (1) are contained in an organic solvent. An electrolyte for a non-aqueous secondary battery.

(In the general formula (1), R ¹ represents an alkyl group, an alkenyl group or —OR ² group. R ² represents an alkyl group or an alkenyl group. At least a part of R ¹ or —OR ² represents the following general formula. The substituent represented by (2), provided that the following general formula (2) with respect to the total molar amount of R ¹ and —OR ² in the entire partial structure represented by the general formula (1) contained in the siloxane oligomer: The molar fraction of the substituent represented by) is 5 mol% or more.)

(In the general formula (2), Q ¹ represents an alkylene group, and R ³ represents an alkyl group.) The siloxane oligomer is selected from the group consisting of the following general formula (1-a), general formula (1-b), general formula (1-c), general formula (1-d), and general formula (1-e). Including a selected partial structure, and the following general formula (1-a), general formula (1-b), general formula (1-c), general formula (1-d), and general formula (1-e) 2. A siloxane oligomer having a branched mole fraction represented by xc + xd + xe of 40 mol% or less, where xa, xb, xc, xd, and xe are the molar fractions of the partial structure represented by Electrolyte for non-aqueous secondary batteries as described in 2.

(In the general formula (1-a) to the general formula (1-e), * and ** are linking sites with other partial structures, and the general formula (1-a) to the general formula (1-e When the partial structures represented by) are linked, they are linked at the position of ** and * .R ¹ and R ² are respectively synonymous with R ¹ and R ² in the general formula (1). The said general formula (2) is represented by the following general formula (3), The electrolyte solution for nonaqueous secondary batteries of Claim 1 or 2 characterized by the above-mentioned.

(In the general formula (3), each R ⁴ independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an aryl group.) The substituents R ¹ and R ² are electrolyte for a non-aqueous secondary battery according to claims 1 is an alkyl group or an alkenyl group having 2 to 4 carbon atoms having 1 to 4 carbon atoms in any one of claims 3 liquid. Non-aqueous liquid electrolyte for a secondary battery according to any one of claims 1 to 4 wherein the substituent Q ¹ is an alkylene group having 1 to 5 carbon atoms. The electrolyte solution for a non-aqueous secondary battery according to claim 3, wherein the substituent R ³ is an alkyl group having 1 to 4 carbon atoms, or R ⁴ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The non-aqueous two according to any one of claims 1 to 6, wherein the substituent R ² is an unsubstituted alkyl group, an alkyl group substituted with a cyano group, or an alkyl group substituted with a halogen atom. Secondary battery electrolyte. In the partial structure represented by the general formula (1) contained in the siloxane oligomer, —OR ² is a substituent represented by the general formula (2), and the general formula (1) contained in the siloxane oligomer. The mole fraction of the substituent represented by the general formula (2) with respect to the total molar amount of R ¹ and —OR ² in the entire partial structure represented is 25 mol% or more and 75 mol% or less. The electrolyte solution for nonaqueous secondary batteries of any one of claim | item 7.   The electrolyte for a non-aqueous secondary battery according to any one of claims 1 to 8, wherein the metal ion or salt thereof belonging to Group 1 or Group 2 of the periodic table is lithium ion or a salt thereof. The electrolyte for a non-aqueous secondary battery according to any one of claims 1 to 9, a positive electrode capable of inserting and releasing metal ions belonging to Group 1 or Group 2 of the periodic table, and the ions A secondary battery comprising a negative electrode capable of insertion / release or dissolution / deposition.

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