TW201940492A - Thermal runaway suppression agent - Google Patents

Abstract

The present invention addresses the issue of providing a non-aqueous electrolyte secondary battery that has no thermal runaway if an internal short-circuit occurs and no risk of fire or explosion, without increasing size or greatly increasing cost. This agent for suppressing thermal runaway caused by internal short-circuits is for a non-aqueous electrolyte secondary battery having: a positive electrode including a positive electrode active substance comprising a silyl ester compound; a negative electrode including a negative electrode active substance, and a non-aqueous electrolyte. In this suppression method for thermal runaway caused by internal short-circuits in non-aqueous electrolyte secondary batteries, 0.01%-10% by mass of the agent for suppressing thermal runaway caused by internal short-circuits, for use in non-aqueous electrolyte secondary batteries, is mixed with the non-aqueous electrolyte.

Description

Thermal runaway inhibitor

The present invention relates to an inhibitor of thermal runaway caused by an internal short circuit of a non-aqueous electrolyte secondary battery, and a method of suppressing thermal runaway caused by an internal short circuit using the inhibitor.

Non-aqueous electrolyte secondary batteries such as lithium ion secondary batteries are widely used as portable computers, handheld camcorders, and information because they are small, lightweight, and have high energy density, high capacity, and can be repeatedly charged and discharged. Terminals, etc. carry power for electronic equipment. In addition, due to environmental concerns, electric vehicles using non-aqueous electrolyte secondary batteries or hybrid electric vehicles using electric power as part of power are being put into practical use.

The non-aqueous electrolyte secondary battery includes members such as an electrode, a separator, and an electrolyte. The main solvent of the electrolyte is a flammable organic solvent. When a large amount of energy is released due to an internal short circuit or the like, thermal runaway may occur and there is a danger of fire or cracking. Therefore, various countermeasures have been studied. As such a countermeasure, a method using a porous film containing polyolefin as a main component as a separator is known (for example, refer to Patent Documents 1 and 2); in addition to the separator, a porous material is provided between the positive electrode and the negative electrode. A method of a heat-resistant layer (for example, refer to Patent Document 3); a method of covering a surface of an electrode active material with a metal oxide (for example, refer to Patent Document 4); and a method for using a lithium-containing nickel oxide as a positive electrode active material (for example, refer to Patent Document) 5); a method of using an olivine-type lithium phosphate compound as a positive electrode active material (for example, refer to Patent Document 6); a method of using a spinel structure lithium titanate compound as a negative electrode active material (for example, refer to Patent Document 7); using a non-combustible material A method of using a fluorine-based solvent as the main solvent of the electrolyte (for example, refer to Patent Documents 8 and 9); a method using a solid electrolyte that does not use an organic solvent as the electrolyte (for example, refer to Patent Document 10);

When using a porous membrane separator with polyolefin as a main component to prevent internal short circuits, the separator must be made thicker. In the method of providing a porous heat-resistant layer, the size of the battery and the porous heat-resistant layer is increased accordingly; In the method of covering the surface of the electrode active material with a metal oxide, the content of the electrode active material contained in the electrode mixture layer of the electrode is relatively reduced and the capacity of the battery is reduced; all of these methods lose small, lightweight, and high-capacity materials. Advantages of non-aqueous electrolyte secondary batteries. In the method of using a lithium-containing nickel oxide or an olivine-type lithium phosphate compound as a positive electrode active material or a method of using a spinel structure lithium titanate compound as a negative electrode active material, a higher charge-discharge capacity cannot be obtained. Further, in the method using a fluorine-based solvent, since the fluorine-based solvent is very expensive and must be used in a large amount, the cost is greatly increased. In the method using a solid electrolyte, since a non-fluid solid electrolyte material is used, internal resistance becomes high, resulting in a decrease in performance compared to an electrolyte using an organic solvent.

On the other hand, for example, in a lithium ion secondary battery, a nonaqueous electrolyte obtained by dissolving a lithium salt containing a fluorine atom such as lithium hexafluorophosphate in a carbonate-based organic solvent such as propylene carbonate or diethyl carbonate is used as the electrolyte. In order to improve the cycle characteristics and the like, it has been studied to further add a carboxylic acid silyl ester compound (for example, refer to Patent Documents 11 to 13), a silyl sulfate compound (for example, refer to Patent Documents 4 to 5), and a sulfonic acid silyl ester compound ( For example, refer to Patent Documents 14, 16), non-aqueous electrolytes of silyl ester compounds such as silyl phosphate compounds (eg, refer to Patent Documents 15, 17, 18), silyl borate compounds (eg, refer to Patent Documents 15, 19). However, it is unknown in the industry that by using a non-aqueous electrolyte to which a silyl ester compound is added, it will become a non-aqueous electrolyte secondary battery that is less prone to thermal runaway and has no danger of fire or cracking even if an internal short circuit occurs.
[Prior technical literature]
[Patent Literature]

[Patent Document 1] US2018097256
[Patent Document 2] US9923181
[Patent Document 3] US7759004
[Patent Document 4] Japanese Patent Laid-Open No. 2011-216300
[Patent Document 5] Japanese Patent Laid-Open No. 2002-015736
[Patent Document 6] US7572548
[Patent Document 7] Japanese Patent Laid-Open No. 2008-159280
[Patent Document 8] US2009253044
[Patent Document 9] US8163422
[Patent Document 10] US2016315324
[Patent Document 11] Japanese Patent Laid-Open No. 2002-313416
[Patent Document 12] US7410731
[Patent Document 13] WO2016 / 013480
[Patent Document 14] US7241536
[Patent Document 15] Japanese Patent Laid-Open No. 2006-253086
[Patent Document 16] US9112236
[Patent Document 17] US6379846
[Patent Document 18] Japanese Patent Laid-Open No. 2004-342607
[Patent Document 19] US2002015895

The object of the present invention is to provide a non-aqueous electrolyte secondary battery, which does not increase in size or increase cost significantly, and even if an internal short circuit occurs, it is difficult to cause thermal runaway without the risk of fire or cracking.

The present inventors have made intensive studies on the above problems, and as a result, they have found that it is not easy to formulate a silane alkyl compound in a nonaqueous electrolyte even in a nonaqueous electrolyte secondary battery having a nonaqueous electrolyte using an organic solvent as a solvent. Thermal runaway occurs, which prevents fire or rupture caused by an internal short circuit, thereby completing the present invention. That is, the present invention is a thermal runaway inhibitor caused by an internal short circuit for a nonaqueous electrolyte secondary battery. The thermal runaway inhibitor includes a silane ester compound. The nonaqueous electrolyte secondary battery has a positive electrode including a positive electrode active material, A negative electrode including a negative electrode active material, and a nonaqueous electrolyte.

The thermal runaway inhibitor of the present invention is characterized in that it comprises a silyl ester compound. Examples of the silyl ester compound include a silyl carboxylate compound, a silyl sulfate compound, a silyl sulfonate compound, a silyl phosphate compound, a silyl phosphite compound, and a silyl borate compound.

Examples of the silyl carboxylate compound include a silyl carboxylate compound represented by the following general formula (1).

[Chemical 1]

(In the formula, R ¹ to R ³ each independently represent a hydrocarbon group having 1 to 6 carbon atoms, and X ¹ represents an a-valent hydrocarbon group having 1 to 10 carbon atoms, or a methylene group in the hydrocarbon group is replaced by an oxygen atom or a sulfur atom. A carbon number of 1 to 10 with a valence base, a represents a number of 1 to 4)

In the general formula (1), R ¹ to R ³ each independently represent a hydrocarbon group having 1 to 6 carbon atoms. Examples of the hydrocarbon group having 1 to 6 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, second butyl, third butyl, and isopentyl , Neopentyl, 1-methylbutyl, isohexyl, vinyl, cyclopentyl, cyclohexyl, phenyl and the like. R ¹ to R ³ are preferably a methyl group, an ethyl group, and a phenyl group, and more preferably a methyl group, in order to increase the effect of suppressing thermal runaway. All of R ¹ to R ³ may be the same base or a combination of 2 to 3 bases, but in the case of a combination of 2 to 3 bases, it is preferable that one of them is a methyl group.

X ¹ represents an a-valent hydrocarbon group having 1 to 10 carbon atoms or an a-valent carbon group having 1 to 10 carbon atoms in which a methylene group in the hydrocarbon group is replaced with an oxygen atom or a sulfur atom, and a represents a number of 1 to 4. When the carbon number of X ¹ is too large, the solubility in the non-aqueous electrolyte may be reduced or the effect of suppressing thermal runaway may be reduced. Therefore, the carbon number of X ¹ is preferably 1 to 10, and more preferably 1 ~ 6. From the viewpoint of the solubility of the carboxylic acid silane alkyl compound in a non-aqueous electrolyte and the stability of the carboxylic acid silane alkyl compound, a is preferably a number from 2 to 3.

The carboxylic acid silyl ester compound represented by the general formula (1) can be obtained by subjecting a carboxylic acid represented by the following general formula (1a) or an anhydride thereof to a silyl ester by a known method.

[Chemical 2]

(In the formula, X ¹ has the same meaning as the general formula (1), and m represents a number of 1 to 4)

Among the silyl carboxylic acid carboxylate compounds represented by the general formula (1), as the compound where a is 1, trimethylsilyl acetate, trimethylsilyl propionate, and trimethylsilyl butyrate can be listed. Ester, trimethylsilyl valerate, trimethylsilyl hexanoate, trimethylsilyl heptanoate, trimethylsilyl octoate, trimethylsilyl nonanoate, trimethyl decanoate Silyl ester, trimethylsilyl 2-methylpropionate, trimethylsilyl 2-methylbutyrate, trimethylsilyl 3-methylbutyrate, trimethyl tertiary butyrate Silyl ester, trimethylsilyl 2-methylvalerate, trimethylsilyl 2-ethylbutyrate, trimethylsilyl isocaproate, trimethylsilyl 2-ethylhexanoate Ester, trimethylsilyl isooctanoate, trimethylsilyl 3,5,5-trimethylhexanoate, trimethylsilyl acrylate, trimethylsilyl methacrylate, butene Acid trimethylsilyl ester, trimethylsilyl benzoate, trimethylsilyl toluate, trimethylsilyl 4-tert-butylbenzoate, trimethylsilyl naphthalate, Phenylacetic acid Trimethylsilyl ester, trimethylsilyl naphthalate, trimethylsilyl 4-methoxybenzoate, trimethylsilyl methoxyacetate, trimethylsilyl ethoxyacetate Ester, trimethylsilyl butoxyacetate, trimethylsilyl phenoxyacetate, and the like.

Among the silyl carboxylic acid carboxylate compounds represented by the general formula (1), examples of the compound in which a is 2 include bis (trimethylsilyl) acetate and bis (trimethylsilyl) malonate. Ester, bis (trimethylsilyl) succinate, bis (trimethylsilyl) glutarate, bis (trimethylsilyl) adipate, bis (trimethylsilyl pimelate) Yl) ester, bis (trimethylsilyl) suberate, bis (trimethylsilyl) azelate, bis (trimethylsilyl) sebacate, bis (trimethyl fumarate) Silyl) ester, maleic acid bis (trimethylsilyl) ester, citraconic acid bis (trimethylsilyl) ester, mesaconic acid bis (trimethylsilyl) ester, pentenedioic acid bis (Trimethylsilyl) ester, bis (trimethylsilyl) iconate, bis (trimethylsilyl) mucofurate, bis (trimethylsilyl) acetylene dicarboxylic acid, cyclic Hexanedicarboxylic acid bis (trimethylsilyl) ester, cyclohexene dicarboxylic acid bis (trimethylsilyl) ester, norbitane dicarboxylic acid bis (trimethylsilyl) ester, norylene dicarboxylate Acid bis (trimethylsilyl) ester, adamantane dicarboxylic acid bis (trimethylsilyl) ester, bicyclo [2.2.1] heptane-2,3- Bis (trimethylsilyl) dicarboxylate, bicyclo [2.2.1] hept-5-ene 2,3-dicarboxylic bis (trimethylsilyl) ester, benzenedicarboxylic acid bis (trimethyl) (Silyl) ester, bis (trimethylsilyl) xylene dicarboxylate, bis (trimethylsilyl) furandicarboxylate, bis (trimethylsilyl) adamantane diacetate, Ethyldioxy) bis (trimethylsilyl) diacetate, (phenylene dioxy) bis (trimethylsilyl) diacetate, bis (trimethylsilyl) thiodiacetate Ester, bis (trimethylsilyl) dithiodiacetate, bis (trimethylsilyl) thiopropionate, bis (trimethylsilyl) thiodipropionate, dithio Bis (trimethylsilyl) dipropionate, bis (trimethylsilyl) diethyldithiodiacetate, bis (trimethylsilyl) thiophene dicarboxylic acid, and the like.

Among the silyl carboxylic acid carboxylate compounds represented by the general formula (1), examples of the compound in which a is 3 include tris (trimethylsilyl) propanetricarboxylate and tris (trimethyltrimethylfurfurate). Silyl) ester, tris (trimethylsilyl) aconitate, 3-butene-1,2,3-tricarboxylic acid tris (trimethylsilyl) ester, pentane-1,3,5 -Tris (trimethylsilyl) tricarboxylate, tris (trimethylsilyl) hexane-1,3,6-tricarboxylic acid, tris (trimethylsilyl) cyclohexanetricarboxylic acid Esters, tris (trimethylsilyl) trimellitate, tris (trimethylsilyl) trimellitate, tris (trimethylsilyl) butanetetracarboxylic acid, and the like.

Among the silyl carboxylic acid carboxylate compounds represented by the general formula (1), as the compound in which a is 4, cyclobutane tetracarboxylic acid tetra (trimethylsilyl) ester, cyclopentane tetracarboxylic acid tetra ( Trimethylsilyl) ester, tetrahydrofuran tetracarboxylic acid tetra (trimethylsilyl) ester, pyromellitic acid tetra (trimethylsilyl) ester, naphthalene tetracarboxylic acid tetra (trimethylsilyl) ester, etc. .

Examples of the silyl sulfate compound and the silyl sulfonate compound include compounds represented by the following general formula (3).

[Chemical 3]

(Wherein R ¹¹ to R ¹⁴ each independently represent a hydrocarbon group having 1 to 6 carbon atoms, and c represents a number of 0 or 1)

In the general formula (3), R ¹¹ to R ¹⁴ represent a hydrocarbon group having 1 to 6 carbon atoms. Examples of the hydrocarbon group having 1 to 6 carbons include the groups exemplified by R ¹ to R ^{3 in} the general formula (1). As R ¹¹ , a methyl group or a phenyl group is preferable, and a methyl group is more preferable in terms of easily obtaining raw materials in industry. As R ¹² to R ¹⁴ , a methyl, ethyl, and phenyl group is preferred, and a methyl group is more preferred in order to increase the effect of suppressing thermal runaway.

c represents a number of 0 or 1. When c is a number of 0, the compound represented by the general formula (3) is a silyl sulfate compound, and when c is a number of 1, it is a silyl sulfonate. Compound.

In the case where c in the general formula (3) is a number of 0, that is, when the compound represented by the general formula (3) is a silyl sulfate compound, as a preferable compound, bis (trimethyl sulfate) can be listed. Silyl) ester, bis (dimethylphenylsilyl) sulfate, bis (methyldiphenylsilyl) sulfate, bis (triphenylsilyl) sulfate, and the like.

In the case where c in the general formula (3) is a number of 1, that is, in the case where the compound represented by the general formula (3) is a silyl sulfonate compound, as a preferable compound, a mesylate three Methylsilyl ester, dimethylphenylsilyl mesylate, trimethylsilyl besylate, trimethylsilyl tosylate, and the like.

Examples of the silyl phosphate compound include a silyl ester compound of an alkyl acidic phosphoric acid ester in which a part of the silyl ester group is replaced with an alkyl ester group. As the silyl phosphite compound, a part of the silyl ester group is exemplified. Silyl ester compound of alkyl acid phosphite substituted with alkyl ester group. Examples of the silyl phosphate compound and the silyl phosphite compound include compounds represented by the following general formula (4).

[Chemical 4]

(Wherein R ¹⁵ to R ¹⁸ each independently represent a hydrocarbon group having 1 to 6 carbon atoms, d represents a number of 0 or 1 to 2 and e represents a number of 0 or 1)

In the general formula (4), R ¹⁵ to R ¹⁸ each independently represent a hydrocarbon group having 1 to 6 carbon atoms. Examples of the hydrocarbon group having 1 to 6 carbons include the groups exemplified by R ¹ to R ^{3 in} the general formula (1). R ¹⁵ is preferably a methyl group, an ethyl group, or a butyl group, and more preferably a methyl group, in order to increase the effect of suppressing thermal runaway. As R ¹⁶ to R ¹⁸ , in order to increase the effect of suppressing thermal runaway, methyl, ethyl, and phenyl are preferred, and methyl is more preferred.

d represents a number of 0 or 1 to 2, and e represents a number of 0 or 1. In the case where d is a number of 1 to 2, a mixture of a compound in which d is a number of 1 and a compound in which d is a number of 2 may be used. When e is a number of 1 and d is a number of 0, the compound represented by the general formula (4) is a silyl phosphate compound, and when e is a number of 1 and d is a number of 1-2, Silyl ester compound of alkyl acid phosphate. When e is a number of 0 and d is a number of 0, the compound represented by the general formula (4) is a silyl phosphite compound, and when e is a number of 0 and d is a number of 1-2 Is a silyl ester compound of an alkyl acid phosphite. Compared with the silyl phosphate compound and the silyl phosphite compound, the silyl ester compound of the alkyl acid phosphoric acid ester and the silyl ester compound of the alkyl acid phosphite have the advantages of being easier to manufacture and having excellent storage stability. .

Examples of silyl phosphate compounds (including silyl compounds of alkyl acid phosphates) include tris (trimethylsilyl) phosphate, methylbis (trimethylsilyl) phosphate, and dimethyl phosphate. (Trimethylsilyl) ester, ethyl bis (trimethylsilyl) phosphate, diethyl (trimethylsilyl) phosphate, butyl bis (trimethylsilyl) phosphate, phosphoric acid Dibutyl (trimethylsilyl) ester and the like. Examples of the silyl phosphite compounds (including silyl ester compounds of alkyl acid phosphites) include tris (trimethylsilyl) phosphite and methylbis (trimethylsilyl) phosphite. Dimethyl (trimethylsilyl) phosphite, ethyl bis (trimethylsilyl) phosphite, diethyl (trimethylsilyl) phosphite, butyl bis (trimethyl phosphite) Methyl silyl) ester, dibutyl phosphite (trimethyl silyl) ester, and the like.

Examples of the silyl borate compound include compounds represented by the following general formula (5).

[Chemical 5]

(Wherein R ¹⁹ to R ²¹ each independently represent a hydrocarbon group having 1 to 6 carbon atoms)

In the general formula (5), R ¹⁹ to R ²¹ each independently represent a hydrocarbon group having 1 to 6 carbon atoms. Examples of the hydrocarbon group having 1 to 6 carbons include the groups exemplified by R ¹ to R ^{3 in} the general formula (1). As R ¹⁹ to R ²¹ , a methyl, ethyl, and phenyl group is preferred, and a methyl group is more preferred in order to increase the effect of suppressing thermal runaway. Examples of the silyl borate compound include tri (trimethylsilyl) borate.

In the present invention, it is preferable to use a silyl carboxylic acid carboxylate compound represented by the general formula (1), since the effect of suppressing thermal runaway is high. In addition, it is preferable that a in the general formula (1) is 2, and X ¹ is preferably a divalent hydrocarbon group having 1 to 10 carbon atoms, or a carbon in which a methylene group in the hydrocarbon group is replaced by an oxygen atom or a sulfur atom. A divalent radical having 1 to 10 atoms. Particularly preferably, R ¹ to R ³ in the general formula (1) are methyl groups, a is 2, X ¹ is a divalent hydrocarbon group having 1 to 6 carbon atoms, or a methylene group in the hydrocarbon group is substituted with a sulfur atom. A divalent compound having 1 to 6 carbon atoms.

In the present invention, a silyl ester compound is formulated as a thermal runaway inhibitor in a non-aqueous electrolyte. The content of the silane alkyl compound in the non-aqueous electrolyte is preferably 0.01% by mass to 10% by mass, more preferably 0.05% by mass to 7% by mass, and most preferably 0.1% by mass to 5% by mass. In the case where the content of the silane alkyl compound in the non-aqueous electrolyte is too small, a sufficient suppression effect of thermal runaway cannot be obtained, and in the case where it is too large, an incremental effect commensurate with the formulated amount cannot be obtained. Regarding the mechanism by which the silyl ester compound in the non-aqueous electrolyte suppresses the thermal runaway caused by the internal short circuit of the non-aqueous electrolyte secondary battery, although it is not very clear, the silicon oxide is seen on the positive and negative surfaces of the non-aqueous electrolyte secondary battery. Because of the adhesion of alkane compounds, it is presumed that during the charge and discharge process, the silane ester compound is decomposed to generate a siloxane compound on the electrode surface, thereby insulating the short-circuit current.

Examples of the non-aqueous electrolyte of the non-aqueous electrolyte secondary battery applicable to the present invention include: a liquid electrolyte obtained by dissolving an electrolyte in an organic solvent; and a high electrolyte obtained by dissolving the electrolyte in an organic solvent and gelating with a polymer. Molecular gel electrolytes; pure polymer electrolytes obtained by dispersing electrolytes in polymers without organic solvents. Among them, in a nonaqueous electrolyte secondary battery having a liquid electrolyte, there is a high risk of fire or explosion due to thermal runaway due to an internal short circuit. Therefore, the thermal runaway inhibitor of the present invention is preferably used for a liquid electrolyte Non-aqueous electrolyte for non-aqueous electrolyte secondary batteries.

As the electrolyte used for the liquid electrolyte and the polymer gel electrolyte, a conventionally known electrolyte is used. Hereinafter, the electrolyte in a case where the non-aqueous electrolyte secondary battery is a lithium secondary battery will be described, but in the case of a sodium secondary battery, an electrolyte obtained by replacing a lithium atom with a sodium atom is used. Examples of the electrolyte used in the liquid electrolyte and the polymer gel electrolyte include LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiN (CF ₃ SO ₂ ) ₂ , and LiN (C ₂ F ₅ SO ₂ ) ₂ , LiN (SO ₂ F) ₂ , LiC (CF ₃ SO ₂ ) ₃ , LiB (CF ₃ SO ₃ ) ₄ , LiB (C ₂ O ₄ ) ₂ , LiBF ₂ (C ₂ O ₄ ), LiSbF ₆ , LiSiF ₅ , LiSCN, LiClO ₄ , LiCl, LiF, LiBr, LiI, LiAlF ₄ , LiAlCl ₄ , LiPO ₂ F ₂ and derivatives thereof, among these, it is preferable to use a member selected from LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiN (SO ₂ F) ₂ , and LiC (CF ₃ SO ₂ ) ₃ and one of LiCF ₃ SO ₃ derivatives and LiC (CF ₃ SO ₂ ) ₃ derivatives. The content of the electrolyte in the liquid electrolyte and the polymer gel electrolyte is preferably 0.5 mol / L to 7 mol / L, and more preferably 0.8 mol / L to 1.8 mol / L.

Examples of the electrolyte used in the pure polymer electrolyte include LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiN (SO ₂ F) ₂ , and LiC (CF ₃ SO ₂ ) ₃ , LiB (CF ₃ SO ₃ ) ₄ , LiB (C ₂ O ₄ ) ₂ .

As the organic solvent used for the preparation of the liquid non-aqueous electrolyte used in the present invention, one or two or more types of ordinary non-aqueous electrolytes can be used by a user. Specific examples include a saturated cyclic carbonate compound, a saturated cyclic ester compound, a fluorene compound, a fluorene compound, a fluorene amine compound, a saturated chain carbonate compound, a chain ether compound, a cyclic ether compound, and a saturated Chain ester compounds and the like.

Among the above organic solvents, saturated cyclic carbonate compounds, saturated cyclic ester compounds, fluorene compounds, sulfonium compounds, and fluorene amine compounds have a relatively high relative dielectric constant, and therefore play a role in increasing the dielectric constant of the non-aqueous electrolyte. Preferably, it is a saturated cyclic carbonate compound. Examples of the saturated cyclic carbonate compound include ethylene carbonate, 1,2-propylene carbonate, 1,3-propylene carbonate, 1,2-butylene carbonate, and 1,3-butyl carbonate. Diesters, 1,1-dimethylethylene carbonate and the like. Examples of the saturated cyclic ester compound include γ-butyrolactone, γ-valerolactone, γ-caprolactone, δ-caprolactone, and δ-caprolactone. Examples of the fluorene compound include dimethyl fluorene, diethyl fluorene, dipropyl fluorene, diphenyl fluorene, and thiophene. Examples of the fluorene compound include dimethylfluorene, diethylfluorene, dipropylfluorene, diphenylfluorene, cyclobutylfluorene (also known as tetramethylenefluorene), and 3-methylcyclobutylfluorene. , 3,4-dimethylcyclobutane, 3,4-diphenylmethylcyclobutane, cyclobutene, 3-methylcyclobutene, 3-ethylcyclobutene, 3- Bromomethylcyclobutenefluorene and the like are preferably cyclobutylfluorene and tetramethylcyclobutylfluorene. Examples of the amidamine compound include N-methylpyrrolidone, dimethylformamide, and dimethylacetamide.

Among the above organic solvents, saturated chain carbonate compounds, chain ether compounds, cyclic ether compounds, and saturated chain ester compounds can provide excellent battery characteristics such as output density, for example, reduce the viscosity of non-aqueous electrolytes, and increase the electrolyte ions. Mobility, etc. In addition, since the viscosity is low, the performance of a non-aqueous electrolyte at a low temperature can be improved, and therefore a saturated chain carbonate compound is particularly preferred. Examples of the saturated chain carbonate compound include dimethyl carbonate, methyl ethyl carbonate, diethyl carbonate, ethyl butyl carbonate, methyl third butyl carbonate, diisopropyl carbonate, and carbonic acid. Tributyl propyl and the like. Examples of the chain ether compound or cyclic ether compound include dimethoxyethane, ethoxymethoxyethane, diethoxyethane, tetrahydrofuran, dioxolane, and difluorene. Alkane, 1,2-bis (methoxycarbonyloxy) ethane, 1,2-bis (ethoxycarbonyloxy) ethane, 1,2-bis (ethoxycarbonyloxy) propane, ethyl Diethylene glycol bis (trifluoroethyl) ether, propylene glycol bis (trifluoroethyl) ether, ethylene glycol bis (trifluoromethyl) ether, diethylene glycol bis (trifluoroethyl) ether, etc. Among them, dioxolane is preferred.

As the saturated chain ester compound, monoester compounds and diester compounds having a total of 2 to 8 carbon atoms in the molecule are preferable. Specific examples of the compound include methyl formate, ethyl formate, and methyl acetate. , Ethyl acetate, propyl acetate, isobutyl acetate, butyl acetate, methyl propionate, ethyl propionate, methyl butyrate, methyl isobutyrate, methyl trimethyl acetate, trimethyl acetate Ethyl ester, methyl malonate, ethyl malonate, methyl succinate, ethyl succinate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethylene glycol Diacetate, propylene glycol diacetate, and the like are preferably methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl acetate, isobutyl acetate, butyl acetate, methyl propionate, and Ethyl propionate.

In addition, as the organic solvent for preparing the non-aqueous electrolyte, for example, acetonitrile, propionitrile, nitromethane, derivatives thereof, and various ionic liquids can be used.

Examples of the polymer used in the polymer gel electrolyte include polyethylene oxide, polypropylene oxide, polyvinyl chloride, polyacrylonitrile, polymethyl methacrylate, polyethylene, polyvinylidene fluoride, Teflon and so on. Examples of the polymer used in the pure polymer electrolyte include polyethylene oxide, polypropylene oxide, and polystyrene sulfonic acid. The blending ratio and the method of compounding in the gel electrolyte are not particularly limited, and a well-known compounding ratio and a known compounding method in the technical field can be adopted.

In order to improve the stability of the silane alkyl compound, the non-aqueous electrolyte preferably further contains a phenylsilane compound represented by the general formula (2).

[Chemical 6]

(Wherein R ⁴ to R ⁵ each independently represent a hydrocarbon group having 1 to 6 carbon atoms, R ⁶ to R ¹⁰ each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, and X ² represents a valence of b Hydrocarbon group, b represents a number of 1 to 3)

In the general formula (2), R ⁴ to R ⁵ each independently represent a hydrocarbon group having 1 to 6 carbon atoms. Examples of the hydrocarbon group having 1 to 6 carbons include the groups exemplified by R ¹ to R ^{3 in} the general formula (1). As R ⁴ to R ⁵ , a methyl, ethyl, and phenyl group is preferred, and a methyl group is more preferred in order to increase the effect of suppressing thermal runaway.

R ⁶ to R ¹⁰ each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, and a second group. Butyl, third butyl. As R <^6> -R <^10> , since a raw material is easily obtained industrially, a hydrogen atom is preferable.

X ² represents a b-valent hydrocarbon group, and b represents a number of 1 to 3. When the carbon number of X ² is too large, the solubility in the non-aqueous electrolyte is reduced. Therefore, the carbon number of X ² is preferably 10 or less.

Among the phenylsilane compounds represented by the general formula (2), preferred compounds include trimethylphenylsilane, dimethyldiphenylsilane, methyltriphenylsilane, and butyldimethylbenzene. Silyl, dimethyloctylphenylsilane, 1,4-bis (trimethylsilyl) benzene, 1,2-bis (trimethylsilyl) benzene, 1,4-bis (dimethylbenzene) Silyl) benzene, 1,1,1-tris (dimethylphenylsilyl) ethane and the like.

Among the electrolytes used in non-aqueous electrolytes, there are cases in which an acidic substance is generated by decomposition, and this type of acidic substance may cause degradation of the performance of the non-aqueous electrolyte secondary battery or decomposition of the silane alkyl compound. The phenyl silane compound represented by the general formula (2) traps such an acidic substance, thereby suppressing degradation of the performance of the non-aqueous electrolyte secondary battery or decomposition of the silane alkyl compound. The amount of the phenylsilane compound represented by the general formula (2) in the non-aqueous electrolyte is preferably 0.1% to 10% by mass, more preferably 0.5% to 7% by mass, and most preferably 1% by mass to 5 mass%. When the content of the non-aqueous electrolyte is too small, a sufficient effect cannot be exerted, and when the content is too large, an incremental effect commensurate with the amount added may not be seen, and the battery performance may be reduced.

The non-aqueous electrolyte may contain an electrode film-forming agent. Examples of the electrode film-forming agent include unsaturated cyclic carbonate compounds such as vinylene carbonate and vinyl ethylene carbonate; and propynes such as dipropargyl carbonate and propargyl carbonate. Chain-like carbonate compounds; unsaturated diester compounds such as dimethyl maleate, dibutyl maleate, dimethyl fumarate, dibutyl fumarate, dimethyl acetylene dicarboxylate; Halogenated cyclic carbonate compounds such as chloroethylene carbonate, dichloroethylene carbonate, fluoroethylene carbonate, and difluoroethylene carbonate; cyclic sulfites such as ethylene sulfite; propane sultone, Cyclic sulfates such as butanesultone.

The electrode film-forming agent forms a protective film called SEI (Solid Electrolyte Interface) on the electrode surface, which improves the charge and discharge efficiency, cycle characteristics, and safety of the battery. In the case where the content of the electrode film-forming agent is too small, a sufficient effect cannot be exerted. In the case where the content of the electrode film-forming agent is too large, not only an incremental effect commensurate with the content but an adverse effect may be caused. Therefore, the electrode film is formed. The content of the agent in the non-aqueous electrolytic solution is preferably 0.005% to 10% by mass, more preferably 0.02% to 5% by mass, and most preferably 0.05% to 3% by mass.

In order to improve battery life, safety, and the like, the non-aqueous electrolyte may further include other known additives such as an antioxidant, a flame retardant, and an overcharge preventing agent.

The positive electrode containing a positive electrode active material of a non-aqueous electrolyte secondary battery used in the present invention is an electrode formed on the current collector with an electrode mixture layer containing the positive electrode active material. For example, an organic solvent or water is used to make the positive electrode active material, Those obtained by slurrying the binder and the conductive auxiliary material are applied to a current collector and dried to form a sheet.

As a positive electrode active material of a positive electrode, a well-known positive electrode active material can be used. Hereinafter, the electrolyte when the non-aqueous electrolyte secondary battery is a lithium secondary battery will be described, but in the case of a sodium secondary battery, a positive electrode active material obtained by replacing a lithium atom with a sodium atom is used.

Examples of well-known positive electrode active materials in the case of lithium secondary batteries include lithium transition metal composite oxides, lithium-containing transition metal phosphate compounds, lithium-containing silicate compounds, and lithium-containing transition metal sulfate compounds. , Sulfur, sulfur compounds and so on. As the transition metal of the lithium transition metal composite oxide, vanadium, titanium, chromium, manganese, iron, cobalt, nickel, copper, and the like are preferred. Specific examples of the lithium transition metal composite oxide include lithium-cobalt composite oxides such as LiCoO ₂ ; lithium-nickel composite oxides such as LiNiO ₂ ; lithium-manganese composite oxides such as LiMnO ₂ , LiMn ₂ O ₄ , and Li ₂ MnO ₃ ; Using aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, lithium, nickel, copper, zinc, magnesium, gallium, zirconium and other metals to replace part of the transition metal atoms of the lithium transition metal composite oxide Finished and so on. Examples of the lithium transition metal composite oxide obtained by replacing a part of the transition metal atom as a host with another metal include Li _1.1 Mn _1.8 Mg _0.1 O ₄ , Li _1.1 Mn _1.85 Al _0.05 O ₄ , and LiNi _0.5 Co _0.2 Mn. _0.3 O ₂ , LiNi _0.8 Co _0.1 Mn _0.1 O ₂ , LiNi _0.5 Mn _0.5 O ₂ , LiNi _0.80 Co _0.17 Al _0.03 O ₂ , LiNi _0.80 Co _0.15 Al _0.05 O ₂ , Li (Ni _1/3 Co _1/3 Mn _{1 / 3} ) O ₂ , LiNi _0.6 Co _0.2 Mn _0.2 O _{2 ,} LiMn _1.8 Al _0.2 O ₄ , LiNi _0.5 Mn _1.5 O ₄ , Li ₂ MnO ₃ -LiMO ₂ (M = Co, Ni, Mn) and the like. As the transition metal of the lithium-containing transition metal phosphate compound, vanadium, titanium, manganese, iron, cobalt, nickel, and the like are preferable. As specific examples, for example, LiFePO ₄ , LiMn _x Fe _1-x PO ₄ (0 <X <1) and other iron phosphate compounds; LiCoPO ₄ and other cobalt phosphate compounds; use aluminum, titanium, vanadium, chromium, manganese, iron, cobalt, lithium, nickel, copper, zinc, magnesium, gallium, zirconium, niobium, etc. The substitution of other metals to form part of the transition metal atoms of the main body of these lithium transition metal phosphate compounds; vanadium phosphate compounds such as Li ₃ V ₂ (PO ₄ ) ₃ and the like. Examples of the lithium-containing silicate compound include Li ₂ FeSiO ₄ and the like. Examples of the lithium-containing transition metal sulfate compound include LiFeSO ₄ and LiFeSO ₄ F. These may be used alone or in combination of two or more.

The thermal runaway inhibitor of the present invention can be preferably used for a non-aqueous electrolyte secondary battery having a large charge and discharge capacity. Examples of the positive electrode active material having a large charge and discharge capacity include LiCoO ₂ , LiMn ₂ O ₄ , LiNi _0.5 Mn _1.5 O ₄ , Li (Ni _0.8 Co _0.15 Al _0.05 ) O ₂ , and LiNi _X Co _Y Mn _Z O ₂ (X + Y + Z = 1, 0 ≦ X ≦ 1, 0 ≦ Y ≦ 1, 0 ≦ Z ≦ 1), LiNiO ₂ , Li ₂ MnO ₃ -LiMO ₂ (M = Co, Ni, Mn), the thermal runaway of the present invention The inhibitor can be preferably used for a nonaqueous electrolyte secondary battery having such a positive electrode active material.

Examples of the adhesive include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), ethylene-propylene-diene copolymer (EPDM), styrene-butadiene rubber (SBR), and acrylonitrile. Butadiene rubber (NBR), styrene-isoprene copolymer, polymethyl methacrylate, polyacrylate, polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC), carboxymethyl cellulose Sodium (CMCNa), methyl cellulose (MC), starch, polyvinylpyrrolidone, polyethylene (PE), polypropylene (PP), polyethylene oxide (PEO), polyimide (PI), Polyammonium imine (PAI), polyacrylonitrile (PAN), polyvinyl chloride (PVC), polyacrylic acid, polyurethane, and the like. The usage-amount of a binder is about 1-20 mass% with respect to a positive electrode active material, Preferably it is 2-10 mass%.

Examples of the conductive auxiliary material include carbon black, Ketjen black, acetylene black, chimney black, furnace black, lamp black, thermal carbon black, nano carbon tubes, Vapor Grown Carbon Fiber (VGCF), Carbon materials such as graphene, fullerene, and needle coke; metal powders such as aluminum powder, nickel powder, and titanium powder; conductive metal oxides such as zinc oxide and titanium oxide; La ₂ S ₃ , Sm ₂ S ₃ , and Ce ₂ S ₃ , TiS ₂ and other sulfides. Regarding the particle diameter of the conductive additive, the average particle diameter is preferably 0.0001 μm to 100 μm, and more preferably 0.01 μm to 50 μm.

As the solvent for slurrying, an organic solvent or water which dissolves the adhesive is used. Examples of the organic solvent include N-methylpyrrolidone, dimethylformamide, dimethylacetamide, methylethyl ketone, cyclohexanone, methyl acetate, methyl acrylate, and diethyl ether. Triamine, N, N-dimethylaminopropylamine, ethylene oxide, tetrahydrofuran and the like. The usage-amount of a solvent is about 10 mass%-400 mass% with respect to a positive electrode active material, Preferably it is 20 mass%-200 mass%.

The current collector of the positive electrode is usually made of aluminum, stainless steel, nickel-plated steel, or the like. Examples of the shape of the current collector include a foil shape, a plate shape, and a mesh shape, and a foil shape is preferable. In the case of a foil, the thickness of the foil is usually 1 μm to 100 μm.

The negative electrode containing a negative electrode active material of the non-aqueous electrolyte secondary battery used in the present invention is an electrode having an electrode mixture layer containing a negative electrode active material formed on a current collector. For example, an organic solvent or water is used to make the negative electrode active material, Those obtained by slurrying the binder and the conductive auxiliary material are applied to a current collector and dried to form a sheet.

As a negative electrode active material of a negative electrode, a well-known negative electrode active material can be used. Hereinafter, the electrolyte in the case where the non-aqueous electrolyte secondary battery is a lithium secondary battery will be described. However, in the case of a sodium secondary battery, the lithium atom of the negative electrode active material having a lithium atom in the negative electrode active material is sodium. Atom-replaced negative active material.

Examples of well-known negative electrode active materials include carbonaceous materials, lithium, lithium alloys, silicon, silicon alloys, silicon oxide, tin, tin alloys, tin oxide, phosphorus, germanium, indium, copper oxide, antimony sulfide, titanium oxide, Iron oxide, manganese oxide, cobalt oxide, nickel oxide, lead oxide, ruthenium oxide, tungsten oxide, zinc oxide, and composite oxides such as LiVO ₂ , Li ₂ VO ₄ , Li ₄ Ti ₅ O ₁₂ , conductive polymers, sulfur Modified polyacrylonitrile and so on. The carbonaceous material is not particularly limited, and examples thereof include natural graphite, artificial graphite, fullerene, graphene, graphite fiber staple fiber, nano carbon tube, graphite whisker, high-alignment pyrolytic graphite, and condensed graphite. Other crystalline carbons, non-graphitizable carbons, easily graphitizable carbons, and petroleum-based coke, coal-based coke, petroleum-based pitch carbides, coal-based pitch carbides, phenol resins-crystalline cellulose and other resin carbides, etc. And carbon materials obtained by carbonizing these portions, furnace black, acetylene black, pitch-based carbon fibers, polyacrylonitrile-based carbon fibers, and the like. When the positive electrode active material is sulfur-modified polyacrylonitrile, a negative electrode active material other than sulfur-modified polyacrylonitrile is used as the negative electrode active material.

Examples of the binder, the conductive auxiliary material, and the solvent for slurrying are the same as those in the case of the positive electrode. The usage-amount of the said binder is about 1 mass%-30 mass% with respect to a negative electrode active material, Preferably it is about 2 mass%-15 mass%. Moreover, the usage-amount of the said solvent is about 10 mass%-400 mass% normally with respect to a negative electrode active material, Preferably it is 20 mass%-200 mass%.

The current collector of the negative electrode usually uses copper, nickel, stainless steel, nickel-plated steel, aluminum, and the like. Examples of the shape of the current collector include a foil shape, a plate shape, and a mesh shape, and a foil shape is preferable. In the case of a foil, the thickness of the foil is usually 1 μm to 100 μm.

In the non-aqueous electrolyte secondary battery to which the present invention is applied, a separator is used between the positive electrode and the negative electrode. As the separator, a generally used microporous membrane of a polymer can be used without particular limitation. Examples of the film include polyethylene, polypropylene, polyvinylidene fluoride, polyvinylidene chloride, polyacrylonitrile, polyacrylamide, polytetrafluoroethylene, polyfluorene, polyetherfluorene, and polycarbonate. Polyethers such as polyamine, polyimide, polyethylene oxide or polypropylene oxide, various celluloses such as carboxymethyl cellulose or hydroxypropyl cellulose, poly (meth) acrylic acid and the like Various esters and other polymer compounds or their derivatives, films of these copolymers or mixtures, etc. These films are made of ceramic materials such as alumina or silica, or magnesium oxide, aromatic polyamide resins, Case of polyvinylidene fluoride coating. When the non-aqueous solvent electrolyte is a pure polymer electrolyte, the separator may not be included.

The non-aqueous electrolyte secondary battery used in the present invention can be a single cell, a laminated battery formed by stacking a plurality of separators between a positive electrode and a negative electrode, or a long sheet-shaped separator, a positive electrode and a negative electrode wound. Any form such as a wound battery, but in view of the high charge and discharge capacity of the battery, and thermal runaway caused by internal short circuits, the present invention is preferably used for a laminated non-aqueous electrolyte secondary battery or a wound battery Non-aqueous electrolyte secondary battery.
[Example]

Hereinafter, the present invention will be specifically described using examples and comparative examples, but these do not limit the scope of the present invention. In addition, "part" or "%" in the examples means those based on quality unless otherwise specified.

[Preparation of non-aqueous electrolyte A]
The non-aqueous electrolyte A was obtained by dissolving LiPF ₆ in a mixed solvent containing 50% by volume of ethylene carbonate and 50% by weight of diethyl carbonate to a concentration of 1.0 mol / L.

[Preparation of non-aqueous electrolytes B to E]
In the non-aqueous electrolyte A, the additives in Table 1 were dissolved so as to have the concentrations described, and non-aqueous electrolytes B to G were obtained.

[Table 1]

[Manufacture of positive electrode 1]
90.0 parts by mass of Li (Ni _1/3 Co _1/3 Mn _1/3 ) O ₂ (manufactured by Japan Chemical Industry, trade name: NCM111) as a positive electrode active material, and 5.0 parts by mass of acetylene black as a conductive additive (Manufactured by the Denki Chemical Industry), 5.0 parts by mass of polyvinylidene fluoride (manufactured by KUREHA) as a binder, mixed with 90 parts by mass of N-methylpyrrolidone, and dispersed using a rotation-revolution mixer to prepare a slurry material. This slurry composition was continuously applied to both sides of a current collector of a roll-shaped aluminum foil (thickness: 20 μm) by a notch wheel coater method, and dried at 90 ° C. for 3 hours. This roll was cut into 50 mm in length and 90 mm in width, and the electrode mixture layer on both sides of one of the lateral side (short side) was removed by 10 mm from the end, and the current collector was exposed, and then the temperature was 150 ° C. Vacuum drying was performed for 2 hours, and the positive electrode 1 was produced.

[Manufacture of positive electrode 2]
Li (Ni _0.8 Co _0.15 Al _0.05 ) O _{2 was used in} place of Li (Ni _1/3 Co _1/3 Mn _1/3 ) O ₂ as the positive electrode active material, except that it was produced in the same order as the production of the positive electrode 1 Li (Ni _0.8 Co _0.15 Al _0.05 ) O _{2 was} used as the positive electrode ₂ of the positive electrode active material.

[Manufacture of negative electrode 1]
92.0 parts by mass of artificial graphite as an electrode active material, 3.5 parts by mass of acetylene black (manufactured by the Denka Chemical Industry) and 1.5 parts by mass of a carbon nanotube (VGCF, manufactured by Showa Denko) as a conductive additive, as 1.5 parts by mass of a styrene-butadiene rubber (aqueous dispersion, manufactured by Ruon Co., Ltd.) and 1.5 parts by mass of sodium carboxymethyl cellulose (manufactured by Daicel Fine Chem) are mixed into 100 parts by mass of water, Dispersion was performed using a rotation-revolution mixer to prepare a slurry. This slurry composition was continuously applied to both sides of a current collector of a roll-shaped copper foil (thickness: 10 μm) by a notch wheel coater method, and dried at 90 ° C. for 3 hours. This roll was cut into 55 mm in length and 95 mm in width, and the electrode mixture layer on both sides of one of the lateral sides (short sides) was removed from the end by 10 mm to expose the current collector at 150 ° C. Vacuum drying was performed for 2 hours, and the negative electrode 1 was produced.

[Manufacture of negative electrode 2]
A negative electrode was fabricated in the same order as the negative electrode 1 except that 87.0 parts by mass of artificial graphite and 5.0 parts by mass of silicon oxide (average particle size: 5 μm) were used instead of 92.0 parts by mass of artificial artificial graphite as an electrode active material. 2.

[Production of laminated battery]
A positive electrode and negative electrode separator (manufactured by Celgard, trade name: Celgard2325) was laminated so as to have the battery capacity shown in Table 2, and a positive electrode terminal and a negative electrode terminal were respectively provided on the positive electrode and the negative electrode to obtain a laminate. . The obtained laminated body and the nonaqueous electrolytes A to G were housed in a flexible film, and laminated batteries of Examples 1 to 8 and Comparative Examples 1 to 6 were obtained.

[Table 2]

[Charging method]
In a constant temperature bath at 30 ° C., the charge termination voltage was set to 4.2 V, the discharge termination voltage was set to 2.75 V, and the charge and discharge were performed once at a charge rate of 0.1 C and a discharge rate of 0.1 C to perform an exhaust treatment. Further, the charge-discharge cycle under the same conditions was performed 5 times, and the charge was performed at a charge rate of 0.1 C to 4.2 V for testing.

[Nail penetration test method]
Fix the battery on a phenol resin plate with a hole with a diameter of 10 mm. At the center of the hole, make iron nails with a diameter of 3 mm and a length of 65 mm perpendicular to the battery surface at a speed of 1 mm / s. Puncture, penetrate 10 mm of the battery, and hold it for 10 minutes before pulling out the nail. Table 3 shows the surface temperature (° C) of the battery just before the battery is nailed, 30 seconds after the nail is nailed, and 5 minutes after the nail is nailed. In addition, the surface temperature of the battery was measured using a thermocouple, and the surface temperature of the battery was 10 mm from the spiked portion.

[table 3]
[Industrial availability]

According to the present invention, it is possible to provide a non-aqueous electrolyte secondary battery, which does not increase in size or greatly increase costs, is small, lightweight, and high-capacity. Even if an internal short circuit occurs, it is not easy to cause thermal runaway without fire or cracking. Danger.

1‧‧‧ positive

1a‧‧‧Positive collector

2‧‧‧ negative

2a‧‧‧Negative current collector

3‧‧‧ Non-aqueous electrolyte

4‧‧‧Positive case

5‧‧‧ negative case

6‧‧‧ pad

7‧‧‧ divider

10‧‧‧ coin type non-aqueous electrolyte secondary battery

10'‧‧‧ cylindrical non-aqueous electrolyte secondary battery

11‧‧‧ Negative

12‧‧‧ negative current collector

13‧‧‧Positive

14‧‧‧Positive collector

15‧‧‧ Non-aqueous electrolyte

16‧‧‧ divider

17‧‧‧Positive terminal

18‧‧‧ negative terminal

19‧‧‧ negative plate

20‧‧‧ Negative lead

21‧‧‧Positive plate

22‧‧‧ Positive lead

23‧‧‧shell

24‧‧‧ Insulation Board

25‧‧‧ cushion

26‧‧‧Safety Valve

27‧‧‧PTC components

FIG. 1 is a longitudinal sectional view schematically showing an example of the structure of a coin-type battery of a non-aqueous electrolyte secondary battery.

Fig. 2 is a schematic diagram showing a basic configuration of a cylindrical battery of a non-aqueous electrolyte secondary battery.

3 is a perspective view showing the internal structure of a cylindrical battery of a non-aqueous electrolyte secondary battery in a cross section.

Claims (6)

An inhibitor of thermal runaway caused by an internal short circuit for a nonaqueous electrolyte secondary battery. The thermal runaway inhibitor includes a silane ester compound. The nonaqueous electrolyte secondary battery has a positive electrode including a positive electrode active material and a negative electrode active material. Negative electrode and non-aqueous electrolyte. The thermal runaway inhibitor according to claim 1, wherein the silyl ester compound is a carboxylic acid silyl ester compound represented by the following general formula (1), [Chem. 1] (In the formula, R ¹ to R ³ each independently represent a hydrocarbon group having 1 to 6 carbon atoms, and X ¹ represents an a-valent hydrocarbon group having 1 to 10 carbon atoms, or a methylene group in the hydrocarbon group is replaced by an oxygen atom or a sulfur atom. A-valent radical having 1 to 10 carbon atoms, a represents a number of 1 to 4). A method for suppressing thermal runaway caused by an internal short-circuit of a non-aqueous electrolyte secondary battery. The thermal runaway inhibitor as claimed in claim 1 or 2 is formulated in a non-aqueous electrolyte in an amount of 0.01% by mass to 10% by mass. The method for suppressing thermal runaway caused by an internal short circuit according to claim 3, wherein the non-aqueous electrolyte is a non-aqueous electrolyte using an organic solvent as a solvent. The method for suppressing thermal runaway caused by an internal short circuit according to claim 3, wherein the non-aqueous electrolyte further contains a phenylsilane compound represented by the following general formula (2), [Chem 2] (Wherein R ⁴ to R ⁵ each independently represent a hydrocarbon group having 1 to 6 carbon atoms, R ⁶ to R ¹⁰ each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, and X ² represents a valence of b Hydrocarbon group, b represents a number of 1 to 3). The method for suppressing thermal runaway caused by an internal short circuit according to claim 3, wherein the positive electrode active material is selected from the group consisting of a lithium transition metal composite oxide, a lithium-containing transition metal phosphate compound, and a lithium-containing silicate compound. At least one.