JP2009054286A - Electrolyte solution and battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery with cycle characteristics improved. <P>SOLUTION: The battery is provided with a cathode 21 and an anode 22 together with the electrolyte solution impregnated in a separator 23 fitted between the cathode 21 and the anode 22. A solvent of the electrolyte solution contains organic cyclic silicon compounds. As compared with the case in which the organic cyclic silicon compounds are not contained, or organic chain silicon compounds are contained, chemical stability of the electrolyte solution is improved to have decomposition reaction restrained, so that a discharge capacity is hardly deteriorated even after repeated charge and discharge. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrolytic solution containing a solvent and a battery using the same.

  In recent years, portable electronic devices such as a camera-integrated VTR (video tape recorder), a mobile phone, or a laptop computer have been widely used, and 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 capable of obtaining a high energy density is underway. Among them, secondary batteries that use the insertion and extraction of lithium for charge / discharge reactions (so-called lithium ion secondary batteries) and secondary batteries that use precipitation and dissolution of lithium (so-called lithium metal secondary batteries) are lead batteries. It is highly anticipated because a large energy density can be obtained as compared with nickel cadmium batteries.

  A combination of a carbonate ester solvent such as propylene carbonate or diethyl carbonate and an electrolyte salt such as lithium hexafluorophosphate is widely used as an electrolyte solution for lithium ion secondary batteries and lithium metal secondary batteries. . This is because the conductivity is high and the potential is stable.

In addition, regarding the composition of the electrolytic solution, several techniques have already been proposed for the purpose of improving various performances. Specifically, in order to improve cycle characteristics and the like, tetraalkoxysilane (for example, see Patent Document 1), trialkylsilane (for example, see Patent Document 2), sulfuric acid or trialkylsilyl ester of sulfurous acid. Compounds having a type structure (for example, see Patent Documents 3 and 4), compounds having a trialkylsilyl ester type structure of malonic acid (for example, Patent Document 5), and polysiloxanes having a cyclic structure (for example, , See Patent Document 6). In addition, linear or cyclic disulfonic acid anhydrides (for example, refer to Patent Documents 7 and 8), cyclic sulfonic acid esters (for example, refer to Patent Document 9), and vinyl disulfone compounds (for example, Patent Document 10). (See also).
JP 2001-266938 A JP 2007-123098 A JP 2002-359001 A JP 2006-244739 JP 2007-123097 A JP 2006-137741 A Japanese Patent No. 3760539 JP 2004-022336 A JP 2005-228631 A JP 2005-135701 A

  Recent portable electronic devices are becoming more sophisticated and multifunctional, and the power consumption is often increased accordingly, and the charge / discharge cycle of the secondary battery tends to be repeated frequently. For this reason, the further improvement is desired regarding the cycling characteristics of a secondary battery.

  The present invention has been made in view of such problems, and an object thereof is to provide an electrolytic solution and a battery capable of improving cycle characteristics.

  The electrolytic solution of the present invention includes a solvent containing an organic cyclic silicon compound having a structure represented by Chemical Formula 1.

（Ｒ１およびＲ２は炭素数１以上４以下のアルキル基、炭素数２以上４以下のアルケニル基あるいはアリール基、またはそれらをハロゲン化した基である。）

(R1 and R2 are an alkyl group having 1 to 4 carbon atoms, an alkenyl group or aryl group having 2 to 4 carbon atoms, or a halogenated group thereof.)

  The battery of the present invention is a battery provided with an electrolyte solution together with a positive electrode and a negative electrode, and the electrolyte solution includes a solvent containing an organic cyclic silicon compound having a structure represented by Chemical Formula 2.

（Ｒ１およびＲ２は炭素数１以上４以下のアルキル基、炭素数２以上４以下のアルケニル基あるいはアリール基、またはそれらをハロゲン化した基である。）

(R1 and R2 are an alkyl group having 1 to 4 carbon atoms, an alkenyl group or aryl group having 2 to 4 carbon atoms, or a halogenated group thereof.)

  According to the electrolytic solution of the present invention, since the solvent contains the organic cyclic silicon compound having the structure shown in Chemical Formula 1, the chemical stability is improved. Thereby, according to the battery provided with the electrolytic solution of the present invention, since the decomposition of the electrolytic solution is suppressed, the cycle characteristics can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  The electrolytic solution according to an embodiment of the present invention is used for an electrochemical device such as a battery, and includes a solvent and an electrolyte salt dissolved in the solvent.

  The solvent contains one or more organic cyclic silicon compounds having a structure represented by Chemical Formula 3. This is because the chemical stability of the electrolytic solution is improved. In addition, R1 and R2 in Chemical Formula 3 may be the same as or different from each other.

（Ｒ１およびＲ２は炭素数１以上４以下のアルキル基、炭素数２以上４以下のアルケニル基あるいはアリール基、またはそれらをハロゲン化した基である。）

(R1 and R2 are an alkyl group having 1 to 4 carbon atoms, an alkenyl group or aryl group having 2 to 4 carbon atoms, or a halogenated group thereof.)

  The reason why R1 and R2 are an alkyl group or the like is because higher chemical stability can be obtained than when they are hydrogen groups. Moreover, the reason why the carbon number of R1 and R2 is within the above-described range is that solubility and compatibility superior to those in the case of outside the range can be obtained. From these, if sufficient chemical stability, solubility and compatibility can be obtained, R1 and R2 are groups in which one or two or more substituents are introduced into the above alkyl group or the like, that is, derivatives. It may be.

  The “group in which they are halogenated” described for R1 and R2 means a group in which at least a part of hydrogen in an alkyl group or the like is substituted with a halogen. The type of the halogen is not particularly limited, but among them, fluorine is preferable. This is because a higher effect can be obtained than halogen other than fluorine. The same applies to “groups obtained by halogenating them” in Chemical Formulas 4 and 5 described later.

  As the organic cyclic silicon compound, at least one of the compounds represented by Chemical Formula 4 and Chemical Formula 5 is preferable. This is because it can be easily synthesized and high chemical stability and excellent solubility can be obtained in the electrolytic solution. In addition, R11 and R12 in Chemical Formula 4 may be the same as or different from each other. The same applies to R21 to R24 in Chemical Formula 5, R25 and R26.

（Ｒ１１およびＲ１２は炭素数１以上４以下のアルキル基、炭素数２以上４以下のアルケニル基あるいはアリール基、またはそれらをハロゲン化した基である。Ｒ１３は炭素数２以上４以下のアルキレン基、炭素数２以上４以下のアルケニレン基あるいは芳香族環を有する２価の基、またはそれらをハロゲン化した基、またはそれらの誘導体である。）

(R11 and R12 are an alkyl group having 1 to 4 carbon atoms, an alkenyl group or aryl group having 2 to 4 carbon atoms, or a halogenated group thereof. R13 is an alkylene group having 2 to 4 carbon atoms, These are alkenylene groups having 2 to 4 carbon atoms, divalent groups having an aromatic ring, halogenated groups thereof, or derivatives thereof.

（Ｒ２１〜Ｒ２４は炭素数１以上４以下のアルキル基、炭素数２以上４以下のアルケニル基あるいはアリール基、またはそれらをハロゲン化した基である。Ｒ２５およびＲ２６は炭素数１以上４以下のアルキレン基、炭素数２以上４以下のアルケニレン基あるいは芳香族環を有する２価の基、またはそれらをハロゲン化した基である。）

(R21 to R24 are an alkyl group having 1 to 4 carbon atoms, an alkenyl group or aryl group having 2 to 4 carbon atoms, or a halogenated group thereof. R25 and R26 are alkylene having 1 to 4 carbon atoms. Group, an alkenylene group having 2 to 4 carbon atoms, a divalent group having an aromatic ring, or a halogenated group thereof.)

  The reason why R11 and R12 are alkyl groups and the like and the reason why their carbon number is within the above-described range are the same as those described for R1 and R2. Of course, R11 and R12 may be a derivative such as an alkyl group.

  The reason why the carbon number of R13 is 2 or more and 4 or less is that higher chemical stability is obtained than when it is 1, and higher solubility and compatibility than when it is 5 or more. In particular, when the number of carbon atoms is 1, the electrolytic solution becomes chemically unstable.

  The “divalent group having an aromatic ring” described for R13 is a general term for a group having one or two or more aromatic rings and being divalent as a whole. For example, an arylene group, one arylene group And a group in which one alkylene group is linked (benzylidene group), or a group in which two alkylene groups are linked through an arylene group. The “aromatic ring” includes a heterocycle. The “derivative thereof” means a group in which one or more substituents are introduced into an alkylene group or the like. The type of the substituent is not particularly limited, and examples thereof include a vinyl group or an allyl group introduced as a side chain into an alkylene group or the like.

  The reason why R21 to R24 are alkyl groups and the like and the reason why their carbon number is within the above-described range are the same as those described for R1 and R2. Of course, R21 to R24 may be a derivative such as an alkyl group.

  The reason why the carbon number of R25 and R26 is 4 or less is that higher solubility and compatibility than in the case of 5 or more are obtained.

  Examples of the compound represented by Chemical Formula 4 include a series of compounds represented by Chemical Formulas 6 to 8. Of these, compounds shown in Chemical formula 6 (1) or Chemical formula 6 (12) are preferable. This is because a high effect can be obtained. Needless to say, the compound is not limited to the compounds shown in Chemical Formulas 6 to 8 as long as it has the structure shown in Chemical Formula 4.

  Before confirmation, in the compounds of Chemical formula 6 (10), Chemical formula 6 (11), Chemical formula 7 (4), Chemical formula 7 (5) or Chemical formula 7 (11), R13 in Chemical formula 4 is a derivative of an alkylene group. This derivative is an ethylene group in which an allyl group is introduced in Chemical formula 6 (10), an ethylene group in which a vinyl group is introduced in Chemical formula 6 (11), a propylene group in which a vinyl group is introduced in Chemical formula 7 (4), 7 (5) is a propylene group having an allyl group introduced therein, and 7 (11) is a butylene group having a vinyl group introduced therein.

  Examples of the compound represented by Chemical formula 5 include a series of compounds represented by Chemical formulas 9 to 14. Needless to say, the compound shown in Chemical Formula 5 is not limited to the compound shown in Chemical Formula 9 to Chemical Formula 14 as long as it has the structure shown in Chemical Formula 5.

  The content of the organocyclic silicon compound in the solvent can be arbitrarily set, but is preferably 0.01% by weight or more and 10% by weight or less. This is because high chemical stability can be obtained in the electrolytic solution. Specifically, if the amount is less than 0.01% by weight, the chemical stability of the electrolytic solution may not be sufficiently and stably obtained. If the amount is more than 10% by weight, the main electrical properties of the electrochemical device may be decreased. There is a possibility that sufficient performance (for example, capacity characteristics in a battery) may not be obtained.

  This solvent preferably contains one or more non-aqueous solvents such as other organic solvents together with the organic cyclic silicon compound. Examples of the non-aqueous solvent 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, ethyl propionate, Methyl butyrate, methyl isobutyrate, methyl trimethylacetate, ethyl trimethylacetate, acetonitrile, glutaronitrile, adiponitrile, methoxyacetonitrile, 3-methoxypropionitrile, N, N-dimethylformamide, N-methylpyrrolidinone, N -Methyloxazolidinone, N, N'-dimethylimidazolidinone, nitromethane, nitroethane, sulfolane, trimethyl phosphate, dimethyl sulfoxide or dimethyl sulfoxide phosphoric acid. 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.

  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.

  The solvent may contain at least one of a chain carbonate ester having a halogen represented by Chemical Formula 15 as a constituent element and a cyclic carbonate ester having a halogen represented by Chemical Formula 16 as a constituent element. . This is because when the electrolytic solution is used in an electrochemical device, a halogen-based film is formed on the electrode, so that the chemical stability of the electrolytic solution is further improved.

（Ｒ３１〜Ｒ３６は水素基、ハロゲン基、アルキル基あるいはハロゲン化アルキル基であり、それらのうちの少なくとも１つはハロゲン基あるいはハロゲン化アルキル基である。）

(R31 to R36 are a hydrogen group, a halogen group, an alkyl group or a halogenated alkyl group, and at least one of them is a halogen group or a halogenated alkyl group.)

（Ｒ４１〜Ｒ４４は水素基、ハロゲン基、アルキル基あるいはハロゲン化アルキル基であり、それらのうちの少なくとも１つはハロゲン基あるいはハロゲン化アルキル基である。）

(R41 to R44 are a hydrogen group, a halogen group, an alkyl group or a halogenated alkyl group, and at least one of them is a halogen group or a halogenated alkyl group.)

  In addition, R31 to R36 in Chemical formula 15 may be the same as or different from each other. The same applies to R41 to R44 in Chemical formula 16. The “halogenated alkyl group” described for R 31 to R 36 or R 41 to R 44 is a group in which at least a part of hydrogen in the alkyl group is substituted with halogen. The type of the halogen is not particularly limited, and examples thereof include at least one selected from the group consisting of fluorine, chlorine and bromine, and among them, fluorine is preferable. This is because a high effect can be obtained. Of course, other halogens may be used.

  Examples of the chain ester carbonate having a halogen shown in Chemical formula 15 include bis (fluoromethyl) carbonate, fluoromethyl methyl carbonate, difluoromethyl methyl carbonate, and the like. These may be used alone or in combination of two or more. Among these, at least one of bis (fluoromethyl) carbonate and fluoromethyl methyl carbonate is preferable. This is because a high effect can be obtained.

  When at least one of R41 to R44 in Chemical formula 16 is an alkyl group or a halogenated alkyl group, the group is preferably a methyl group, an ethyl group, a halogenated methyl group or a halogenated ethyl group. This is because a high effect can be obtained.

  Examples of the cyclic carbonate having a halogen shown in Chemical formula 16 include a series of compounds represented by Chemical formula 17 and Chemical formula 18. That is, 4-fluoro-1,3-dioxolan-2-one of (1) shown in Chemical formula 17, 4-chloro-1,3-dioxolan-2-one of (2), 4,5 of (3) -Difluoro-1,3-dioxolan-2-one, (4) tetrafluoro-1,3-dioxolan-2-one, (5) 4-fluoro-5-chloro-1,3-dioxolane-2-one ON, (6) 4,5-dichloro-1,3-dioxolan-2-one, (7) tetrachloro-1,3-dioxolan-2-one, (8) 4,5-bistrifluoromethyl 1,3-dioxolan-2-one, 4-trifluoromethyl-1,3-dioxolan-2-one of (9), 4,5-difluoro-4,5-dimethyl-1,3 of (10) -Dioxolan-2-one, 4-methyl-5 of (11) - difluoro-1,3-dioxolane-2-one, and the like 5,5-difluoro-1,3-dioxolan-2-one (12). Further, 4-trifluoromethyl-5-fluoro-1,3-dioxolan-2-one of (1) shown in Chemical formula 18, 4-trifluoromethyl-5-methyl-1,3-dioxolane of (2) 2-one, 4-fluoro-4,5-dimethyl-1,3-dioxolan-2-one of (3), 4,4-difluoro-5- (1,1-difluoroethyl)-of (4) 1,3-dioxolan-2-one, 4,5-dichloro-4,5-dimethyl-1,3-dioxolan-2-one in (5), 4-ethyl-5-fluoro-1, in (6) 3-dioxolan-2-one, 4-ethyl-4,5-difluoro-1,3-dioxolan-2-one of (7), 4-ethyl-4,5,5-trifluoro-1 of (8) , 3-Dioxolan-2-one, 4-fluoro-4-methyl- of (9) , 3-dioxolane-2-one.

  These may be used alone or in combination of two or more. Among these, at least one of 4-fluoro-1,3-dioxolan-2-one and 4,5-difluoro-1,3-dioxolan-2-one is preferable, and 4,5-difluoro-1,3- Dioxolan-2-one is more preferred. This is because they are easily available and higher effects can be obtained. In particular, 4,5-difluoro-1,3-dioxolan-2-one is preferably a trans isomer rather than a cis isomer.

  Further, the solvent may contain sultone (cyclic sulfonic acid ester) or an acid anhydride. This is because the chemical stability of the electrolytic solution is further improved.

  Examples of sultone include propane sultone and propene sultone. These may be used alone or in combination of two or more. Of these, propene sultone is preferable. Further, the sultone content in the solvent is preferably 0.5% by weight or more and 3% by weight or less. This is because a high effect can be obtained in any case.

  Examples of the acid anhydride include carboxylic anhydrides such as succinic anhydride, glutaric anhydride or maleic anhydride, disulfonic anhydrides such as ethanedisulfonic anhydride or propanedisulfonic anhydride, sulfobenzoic anhydride, anhydrous Examples thereof include anhydrides of carboxylic acid and sulfonic acid such as sulfopropionic acid or sulfobutyric anhydride. These may be used alone or in combination of two or more. Of these, anhydrous sulfobenzoic acid is preferable. Moreover, it is preferable that content of the acid anhydride in a solvent is 0.5 to 3 weight%. This is because a high effect can be obtained in any case.

  For example, the intrinsic viscosity of the solvent is preferably 10.0 mPa · s or less at 25 ° C. This is because the dissociation property of the electrolyte salt and the mobility of ions can be secured. For the same reason, the intrinsic viscosity in a state where the electrolyte salt is dissolved in the solvent (that is, the intrinsic viscosity of the electrolytic solution) is preferably 10.0 mPa · s or less at 25 ° C.

The electrolyte salt contains, for example, one or more light metal salts such as a lithium salt. As this lithium salt, for example, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium tetraphenylborate (LiB (C ₆ H ₅ ) ₄ ), Lithium methanesulfonate (LiCH ₃ SO ₃ ), lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ), lithium tetrachloroaluminate (LiAlCl ₄ ), dilithium hexafluorosilicate (Li ₂ SiF ₆ ), lithium chloride ( LiCl) or lithium bromide (LiBr). Among these, at least one selected from the group consisting of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, and lithium hexafluoroarsenate is preferable, and lithium hexafluorophosphate is more preferable. This is because the resistance of the electrolytic solution decreases. In particular, it is preferable to use lithium tetrafluoroborate together with lithium hexafluorophosphate. This is because a higher effect can be obtained.

  This electrolyte salt may contain at least one selected from the group consisting of compounds represented by Chemical Formula 19, Chemical Formula 20, and Chemical Formula 21. This is because a higher effect can be obtained when used together with the above-described lithium hexafluorophosphate or the like. In addition, R53 in Chemical formula 19 may be the same as or different from each other. The same applies to R61 to R63 in Chemical formula 20 and R71 and R72 in Chemical formula 21.

（Ｘ５１は短周期型周期表における１Ａ族元素あるいは２Ａ族元素、またはアルミニウム（Ａｌ）である。Ｍ５１は遷移金属、または短周期型周期表における３Ｂ族元素、４Ｂ族元素あるいは５Ｂ族元素である。Ｒ５１はハロゲン基である。Ｙ５１は−ＯＣ−Ｒ５２−ＣＯ−、−ＯＣ−ＣＲ５３₂ −あるいは−ＯＣ−ＣＯ−である。ただし、Ｒ５２はアルキレン基、ハロゲン化アルキレン基、アリーレン基あるいはハロゲン化アリーレン基である。Ｒ５３はアルキル基、ハロゲン化アルキル基、アリール基あるいはハロゲン化アリール基である。なお、ａ５は１〜４の整数であり、ｂ５は０、２あるいは４の整数であり、ｃ５、ｄ５、ｍ５およびｎ５は１〜３の整数である。）

(X51 is a 1A group element or 2A group element in the short periodic table, or aluminum (Al). M51 is a transition metal, or a 3B group element, 4B group element, or 5B group element in the short period type periodic table. R51 is a halogen group, Y51 is —OC—R52—CO—, —OC—CR53 ₂ — or —OC—CO—, wherein R52 is an alkylene group, a halogenated alkylene group, an arylene group or a halogenated group. R53 is an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group, wherein a5 is an integer of 1 to 4, b5 is an integer of 0, 2 or 4, and c5 , D5, m5 and n5 are integers of 1 to 3.)

（Ｘ６１は短周期型周期表における１Ａ族元素あるいは２Ａ族元素である。Ｍ６１は遷移金属、または短周期型周期表における３Ｂ族元素、４Ｂ族元素あるいは５Ｂ族元素である。Ｙ６１は−ＯＣ−（ＣＲ６１₂ ）_b6−ＣＯ−、−Ｒ６３₂ Ｃ−（ＣＲ６２₂ ）_c6−ＣＯ−、−Ｒ６３₂ Ｃ−（ＣＲ６２₂ ）_c6−ＣＲ６３₂ −、−Ｒ６３₂ Ｃ−（ＣＲ６２₂ ）_c6−ＳＯ₂ −、−Ｏ₂ Ｓ−（ＣＲ６２₂ ）_d6−ＳＯ₂ −あるいは−ＯＣ−（ＣＲ６２₂ ）_d6−ＳＯ₂ −である。ただし、Ｒ６１およびＲ６３は水素基、アルキル基、ハロゲン基あるいはハロゲン化アルキル基であり、それぞれのうちの少なくとも１つはハロゲン基あるいはハロゲン化アルキル基である。Ｒ６２は水素基、アルキル基、ハロゲン基あるいはハロゲン化アルキル基である。なお、ａ６、ｅ６およびｎ６は１あるいは２の整数であり、ｂ６およびｄ６は１〜４の整数であり、ｃ６は０〜４の整数であり、ｆ６およびｍ６は１〜３の整数である。）

(X61 is a group 1A element or a group 2A element in the short period type periodic table. M61 is a transition metal, or a group 3B element, a group 4B element, or a group 5B element in the short period type periodic table. Y61 is —OC—. _{(CR61 2) b6 -CO -,} - R63 2 C- (CR62 2) c6 -CO -, - R63 2 C- (CR62 2) c6 -CR63 2 -, - R63 2 C- (CR62 2) c6 -SO ₂ —, —O ₂ S— (CR62 ₂ ) _d6 —SO ₂ — or —OC— (CR62 ₂ ) _d6 —SO ₂ —, wherein R61 and R63 are hydrogen, alkyl, halogen, or halogenated An alkyl group, at least one of which is a halogen group or a halogenated alkyl group, and R62 is a hydrogen group, an alkyl group, a halogen group or a halogenated alkyl group. A6, e6 and n6 are integers of 1 or 2, b6 and d6 are integers of 1 to 4, c6 is an integer of 0 to 4, and f6 and m6 are integers of 1 to 3. )

（Ｘ７１は短周期型周期表における１Ａ族元素あるいは２Ａ族元素である。Ｍ７１は遷移金属、または短周期型周期表における３Ｂ族元素、４Ｂ族元素あるいは５Ｂ族元素である。Ｒｆはフッ素化アルキル基あるいはフッ素化アリール基であり、そのいずれの炭素数も１〜１０である。Ｙ７１は−ＯＣ−（ＣＲ７１₂ ）_d7−ＣＯ−、−Ｒ７２₂ Ｃ−（ＣＲ７１₂ ）_d7−ＣＯ−、−Ｒ７２₂ Ｃ−（ＣＲ７１₂ ）_d7−ＣＲ７２₂ −、−Ｒ７２₂ Ｃ−（ＣＲ７１₂ ）_d7−ＳＯ₂ −、−Ｏ₂ Ｓ−（ＣＲ７１₂ ）_e7−ＳＯ₂ −あるいは−ＯＣ−（ＣＲ７１₂ ）_e7−ＳＯ₂ −である。ただし、Ｒ７１は水素基、アルキル基、ハロゲン基あるいはハロゲン化アルキル基である。Ｒ７２は水素基、アルキル基、ハロゲン基あるいはハロゲン化アルキル基であり、そのうちの少なくとも１つはハロゲン基あるいはハロゲン化アルキル基である。なお、ａ７、ｆ７およびｎ７は１あるいは２の整数であり、ｂ７、ｃ７およびｅ７は１〜４の整数であり、ｄ７は０〜４の整数であり、ｇ７およびｍ７は１〜３の整数である。）

(X71 is a group 1A element or a group 2A element in the short period type periodic table. M71 is a transition metal, or a group 3B element, a group 4B element, or a group 5B element in the short period type periodic table. Rf is a fluorinated alkyl. Or a fluorinated aryl group, each having 1 to 10 carbon atoms, Y71 is —OC— (CR71 ₂ ) _d7 —CO—, —R72 ₂ C— (CR71 ₂ ) _d7 —CO—, — _{R72 2 C- (CR71 2) d7} -CR72 2 -, - R72 2 C- (CR71 2) d7 -SO 2 -, - O 2 S- (CR71 2) e7 -SO 2 - or -OC- (CR71 ₂ ) _e7 -SO ₂ -. is, however, R71 is a hydrogen group, an alkyl group, a halogen group or a halogenated alkyl group .R72 hydrogen group, an alkyl group, a halogen group or a halogenated alkyl group And at least one of them is a halogen group or a halogenated alkyl group, wherein a7, f7 and n7 are integers of 1 or 2, b7, c7 and e7 are integers of 1 to 4, and d7 is (It is an integer of 0 to 4, and g7 and m7 are integers of 1 to 3.)

  Examples of the compound shown in Chemical formula 19 include compounds represented by Chemical formulas (1) to (6). Examples of the compound shown in Chemical formula 20 include the compounds represented by chemical formulas (1) to (8) in Chemical formula 23. Examples of the compound represented by Chemical formula 21 include the compound represented by Chemical formula 24. Of these, the compound shown in Chemical Formula 22 (6) is preferable. This is because a high effect can be obtained. Needless to say, the compound having the structure shown in Chemical Formula 19 to Chemical Formula 21 is not limited to the compound shown in Chemical Formula 22 to Chemical Formula 24.

  The electrolyte salt may contain at least one selected from the group consisting of compounds represented by Chemical Formula 25, Chemical Formula 26 and Chemical Formula 27. This is because a higher effect can be obtained when used together with the above-described lithium hexafluorophosphate or the like. In the chemical formula 25, m and n may be the same as or different from each other. The same applies to p, q and r in Chemical Formula 27.

（ｍおよびｎは１以上の整数である。）

(M and n are integers of 1 or more.)

（Ｒ８１は炭素数２以上４以下の直鎖状あるいは分岐状のパーフルオロアルキレン基である。）

(R81 is a linear or branched perfluoroalkylene group having 2 to 4 carbon atoms.)

（ｐ、ｑおよびｒは１以上の整数である。）

(P, q and r are integers of 1 or more.)

Examples of the chain compound shown in Chemical Formula 25 include bis (trifluoromethanesulfonyl) imide lithium (LiN (CF ₃ SO ₂ ) ₂ ), bis (pentafluoroethanesulfonyl) imide lithium (LiN (C ₂ F ₅ SO ₂ ) ₂ ), (trifluoromethanesulfonyl) (pentafluoroethanesulfonyl) imide lithium (LiN (CF ₃ SO ₂ ) (C ₂ F ₅ SO ₂ )), (trifluoromethanesulfonyl) (heptafluoropropanesulfonyl) imide lithium ( LiN (CF ₃ SO ₂ ) (C ₃ F ₇ SO ₂ )) or (trifluoromethanesulfonyl) (nonafluorobutanesulfonyl) imidolithium (LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ )) It is done. These may be used alone or in combination of two or more.

  Examples of the cyclic compound represented by Chemical formula 26 include a series of compounds represented by Chemical formula 28. That is, 1,2-perfluoroethanedisulfonylimide lithium of (1) shown in Chemical formula 28, 1,3-perfluoropropane disulfonylimide lithium of (2), 1,3-perfluorobutane of (3) Disulfonylimide lithium, 1,4-perfluorobutane disulfonylimide lithium of (4), and the like. These may be used alone or in combination of two or more.

Examples of the chain compound shown in Chemical formula 27 include lithium tris (trifluoromethanesulfonyl) methide (LiC (CF ₃ SO ₂ ) ₃ ).

  The content of the electrolyte salt is preferably 0.3 mol / kg or more and 3.0 mol / kg or less with respect to the solvent. This is because, outside this range, the ion conductivity may be extremely lowered.

  According to this electrolytic solution, since the solvent contains the organic cyclic silicon compound having the structure shown in Chemical formula 3, the organic chain silicon compound represented by Chemical formula 29 or Chemical formula 30 can be used. Compared with the case of containing, chemical stability improves. The organic chain silicon compound shown in Chemical formula 29 is a chain compound having the structure shown in Chemical formula 3, and the organic chain silicon compound shown in Chemical formula 30 is tetramethoxysilane. Therefore, when used in an electrochemical device such as a battery, the decomposition reaction is suppressed, which can contribute to the improvement of cycle characteristics. In this case, if the organic cyclic silicon compound is a compound shown in Chemical Formula 4 or Chemical Formula 5 or the content of the organic cyclic silicon compound in the solvent is 0.01 wt% or more and 10 wt% or less, High effect can be obtained.

  Further, the solvent is at least one of a cyclic carbonate having an unsaturated bond, a chain carbonate having a halogen shown in Chemical formula 15 and a cyclic carbonate having a halogen shown in Chemical formula 16, sultone, If an acid anhydride is contained, a higher effect can be obtained.

  Further, the electrolyte salt is represented by at least one selected from the group consisting of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate and lithium hexafluoroarsenate, and A higher effect can be obtained if it contains at least one member selected from the group consisting of compounds and at least one member selected from the group consisting of compounds shown in Chemical Formulas 25 to 27.

  Next, usage examples of the above-described electrolytic solution will be described. Here, as an example of an electrochemical device, taking a battery as an example, the electrolytic solution is used as follows.

(First battery)
FIG. 1 shows a cross-sectional configuration of the first battery. This battery is, for example, a lithium ion secondary battery in which the capacity of the negative electrode is expressed based on insertion and extraction of lithium which is a battery reactant.

  This secondary battery mainly includes a wound electrode body 20 in which a positive electrode 21 and a negative electrode 22 are wound through a separator 23 inside a substantially hollow cylindrical battery can 11, a pair of insulating plates 12, 13 is stored. The battery can 11 is made of, for example, a metal material such as nickel (Ni) plated iron (Fe), and one end and the other end thereof are closed and opened, respectively. The pair of insulating plates 12 and 13 are arranged so as to extend perpendicular to the winding peripheral surface with the winding electrode body 20 interposed therebetween. The battery structure using the cylindrical battery can 11 is called a cylindrical type.

  A battery lid 14 and a safety valve mechanism 15 and a heat sensitive resistance element (Positive Temperature Coefficient; PTC element) 16 provided on the inside of the battery can 11 are caulked to the open end of the battery can 11 via a gasket 17. The inside of the battery can 11 is sealed. The battery lid 14 is made of a metal material similar to that of the battery can 11, for example. The safety valve mechanism 15 is electrically connected to the battery lid 14 via the heat sensitive resistance element 16. In this safety valve mechanism 15, when the internal pressure becomes a certain level or more due to an internal short circuit or external heating, the disk plate 15A is reversed and the electrical connection between the battery lid 14 and the wound electrode body 20 is cut. It has come to be. The heat sensitive resistive element 16 limits the current by increasing the resistance according to the temperature rise, and prevents abnormal heat generation due to a large current. The gasket 17 is made of, for example, an insulating material, and asphalt is applied to the surface thereof.

  A center pin 24 may be inserted in the center of the wound electrode body 20. In this wound electrode body 20, a positive electrode lead 25 made of a metal material such as aluminum is connected to the positive electrode 21, and a negative electrode lead 26 made of a metal material such as nickel is connected to the negative electrode 22. . The positive electrode lead 25 is welded to the safety valve mechanism 15 and is electrically connected to the battery lid 14, and the negative electrode lead 26 is welded to and electrically connected to the battery can 11.

  FIG. 2 shows an enlarged part of the spirally wound electrode body 20 shown in FIG. For example, the positive electrode 21 is obtained by providing a positive electrode active material layer 21B on both surfaces of a positive electrode current collector 21A having a pair of surfaces. However, the positive electrode active material layer 21B may be provided only on one surface of the positive electrode current collector 21A.

  The positive electrode current collector 21A is made of a metal material such as aluminum, nickel, or stainless steel, for example. The positive electrode active material layer 21B includes one or more positive electrode materials capable of occluding and releasing lithium as a positive electrode active material, and a conductive agent, a binder, and the like as necessary. Other materials may be included.

Examples of the positive electrode material capable of inserting and extracting lithium include iron sulfide (FeS ₂ ), titanium sulfide (TiS ₂ ), molybdenum sulfide (MoS ₂ ), niobium selenide (NbSe ₂ ), and vanadium oxide (V Examples thereof include chalcogenides containing no lithium such as ₂ O ₅ ) or lithium-containing compounds containing lithium.

Among these, lithium-containing compounds are preferable because some compounds can obtain a high voltage and a high energy density. Examples of such a lithium-containing compound include a composite oxide containing lithium and a transition metal element, or a phosphoric acid compound containing lithium and a transition metal element. In particular, the group consisting of cobalt, nickel, manganese, and iron Those containing at least one of them are preferred. This is because a higher voltage can be obtained. The chemical formula is represented by, for example, Li _x MIO ₂ or Li _y MIIPO ₄ . In the formula, MI and MII represent one or more transition metal elements. The values of x and y vary depending on the charge / discharge state of the battery, and are generally 0.05 ≦ x ≦ 1.10 and 0.05 ≦ y ≦ 1.10.

Specific examples of the composite oxide containing lithium and a transition metal element include lithium cobalt composite oxide (Li _x CoO ₂ ), lithium nickel composite oxide (Li _x NiO ₂ ), and lithium nickel cobalt composite oxide (Li _x Ni _1-z Co _z O ₂ (z <1)), lithium nickel cobalt manganese composite oxide (Li _x Ni _(1-vw) Co _v Mn _w O ₂ (v + w <1)), or a spinel structure Examples thereof include lithium manganese composite oxide (LiMn ₂ O ₄ ). Among these, a composite oxide containing nickel is preferable. This is because a high capacity can be obtained and excellent cycle characteristics can be obtained. Specific examples of the phosphate compound containing lithium and a transition metal element include, for example, a lithium iron phosphate compound (LiFePO ₄ ) or a lithium iron manganese phosphate compound (LiFe _1-u Mn _u PO ₄ (u <1)). Etc.

  In addition, examples of the positive electrode material include oxides such as titanium oxide, vanadium oxide, and manganese dioxide, and conductive polymers such as sulfur, polyaniline, and polythiophene.

  In the negative electrode 22, for example, a negative electrode active material layer 22B is provided on both surfaces of a negative electrode current collector 22A having a pair of surfaces. However, the negative electrode active material layer 22B may be provided only on one surface of the negative electrode current collector 22A. The anode current collector 22A is preferably made of a metal material having good electrochemical stability, electrical conductivity, and mechanical strength. Examples of the metal material include copper (Cu), nickel, and stainless steel, and copper is particularly preferable. This is because high electrical conductivity can be obtained.

  The negative electrode active material layer 22B contains one or more negative electrode materials capable of inserting and extracting lithium as a negative electrode active material, and a conductive agent, a binder, and the like as necessary. Other materials may be included. Note that the charge capacity of the negative electrode material capable of inserting and extracting lithium is preferably larger than the charge capacity of the positive electrode active material.

  Examples of the negative electrode material capable of inserting and extracting lithium include a carbon material. Examples of such a carbon material include graphitizable carbon, non-graphitizable carbon having a (002) plane spacing of 0.37 nm or more, or graphite having a (002) plane spacing of 0.34 nm or less. Etc. More specifically, there are pyrolytic carbons, cokes, graphites, glassy carbon fibers, fired organic polymer compounds, carbon fibers, activated carbon, carbon blacks, and the like. Among these, coke includes pitch coke, needle coke, petroleum coke, and the like, and the organic polymer compound fired body is obtained by firing and carbonizing a phenol resin, a furan resin, or the like at an appropriate temperature. A carbon material is preferable because it has a very small change in crystal structure due to insertion and extraction of lithium, so that a high energy density is obtained and an excellent cycle characteristic is obtained, and it also functions as a conductive agent.

  Examples of the negative electrode material capable of occluding and releasing lithium include, for example, a material capable of occluding and releasing lithium and having at least one of a metal element and a metalloid element as a constituent element. Can be mentioned. Such a negative electrode material is preferable because a high energy density is obtained. This negative electrode material may be a single element or an alloy or a compound of a metal element or a metalloid element, or may have at least a part of one or more of these phases. Here, the alloy in the present invention includes an alloy containing one or more metal elements and one or more metalloid elements in addition to an alloy composed of two or more metal elements. The alloy in the present invention may contain a nonmetallic element. This structure includes a solid solution, a eutectic (eutectic mixture), an intermetallic compound, or a mixture of two or more of them.

  Examples of the metal element or metalloid element constituting the negative electrode material include a metal element or metalloid element capable of forming an alloy with lithium. Specifically, magnesium (Mg), boron (B), aluminum, gallium (Ga), indium (In), silicon, germanium (Ge), tin, lead (Pb), bismuth (Bi), cadmium (Cd) Silver (Ag), zinc (Zn), hafnium (Hf), zirconium (Zr), yttrium (Y), palladium (Pd), platinum (Pt), and the like. Among these, at least one of silicon and tin is particularly preferable. This is because a high energy density can be obtained because the ability to occlude and release lithium is large.

  Examples of the material having at least one of silicon and tin include at least one selected from the group consisting of a simple substance, an alloy and a compound of silicon, and a simple substance, an alloy and a compound of tin. That is, it is a material having at least a part of a simple substance, an alloy or a compound of silicon, a simple substance, an alloy or a compound of tin, or one or more phases thereof.

  Examples of the silicon alloy include tin, nickel, copper, iron, cobalt (Co), manganese (Mn), zinc, indium, silver, titanium, germanium, bismuth and antimony (second constituent elements other than silicon). Examples include those containing at least one of the group consisting of Sb) and chromium. As an alloy of tin, for example, as a second constituent element other than tin, among the group consisting of silicon, nickel, copper, iron, cobalt, manganese, zinc, indium, silver, titanium, germanium, bismuth, antimony and chromium The thing containing at least 1 sort (s) of these is mentioned.

  Examples of the silicon compound or the tin compound include those containing oxygen (O) or carbon (C), and may contain the second constituent element described above in addition to silicon or tin.

  In particular, as a material having at least one of silicon and tin, tin is a first constituent element, and a material containing a second constituent element and a third constituent element in addition to the tin is preferable. The second constituent element is cobalt, iron, magnesium, titanium, vanadium (V), chromium, manganese, nickel, copper, zinc, gallium, zirconium, niobium (Nb), molybdenum (Mo), silver, indium, cerium ( Ce), hafnium, tantalum (Ta), tungsten (W), bismuth and silicon. The third constituent element is at least one selected from the group consisting of boron, carbon, aluminum, and phosphorus. This is because the cycle characteristics are improved by including the second and third constituent elements.

  Among these, tin, cobalt and carbon are included as constituent elements, and the carbon content is in the range of 9.9 mass% to 29.7 mass%, and the ratio of cobalt to the total of tin and cobalt (Co / (Sn + Co)) Is preferably a CoSnC-containing material in the range of 30% by mass to 70% by mass. This is because a high energy density can be obtained in such a composition range.

  This CoSnC-containing material may further contain other constituent elements as necessary. As other constituent elements, for example, silicon, iron, nickel, chromium, indium, niobium, germanium, titanium, molybdenum, aluminum, phosphorus, gallium, or bismuth are preferable, and two or more of them may be included. This is because a higher effect can be obtained.

  The CoSnC-containing material has a phase containing tin, cobalt and carbon, and the phase preferably has a low crystalline structure or an amorphous structure. In the CoSnC-containing material, it is preferable that at least a part of carbon that is a constituent element is bonded to a metal element or a metalloid element that is another constituent element. This is because tin or the like is suppressed from aggregation or crystallization.

  Moreover, as a measuring method for examining the bonding state of elements, for example, X-ray photoelectron spectroscopy (XPS) can be cited. In this XPS, in the apparatus calibrated so that the 4f orbit (Au4f) peak of gold atom is obtained at 84.0 eV, the peak of 1s orbit (C1s) of carbon appears at 284.5 eV in the case of graphite. . Moreover, if it is surface contamination carbon, it will appear at 284.8 eV. On the other hand, when the charge density of the carbon element is high, for example, when carbon is bonded to a metal element or a metalloid element, the peak of C1s appears in a region lower than 284.5 eV. That is, when the peak of the synthetic wave of C1s obtained for the CoSnC-containing material appears in a region lower than 284.5 eV, at least a part of the carbon contained in the CoSnC-containing material is a metal element or a half of other constituent elements. Combined with metal elements.

  In XPS, for example, the peak of C1s is used to correct the energy axis of the spectrum. Usually, since surface-contaminated carbon exists on the surface, the C1s peak of the surface-contaminated carbon is set to 284.8 eV, which is used as an energy standard. In XPS, the waveform of the C1s peak is obtained as a form including the surface contamination carbon peak and the carbon peak in the CoSnC-containing material. For example, by analyzing using commercially available software, the surface contamination The carbon peak and the carbon peak in the CoSnC-containing material are separated. In the waveform analysis, the position of the main peak existing on the lowest bound energy side is used as the energy reference (284.8 eV).

  Furthermore, examples of the negative electrode material capable of inserting and extracting lithium include metal oxides and polymer compounds capable of inserting and extracting lithium. Examples of the metal oxide include iron oxide, ruthenium oxide, and molybdenum oxide. Examples of the polymer compound include polyacetylene, polyaniline, and polypyrrole.

  Of course, you may use combining the negative electrode material which can occlude and discharge | release the above-mentioned series of lithium.

  Examples of the conductive agent include carbon materials such as graphite, carbon black, and ketjen black. These may be used alone or in combination of two or more. Note that the conductive agent may be a metal material or a conductive polymer as long as it is a conductive material.

  Examples of the binder include synthetic rubbers such as styrene butadiene rubber, fluorine rubber or ethylene propylene diene, and polymer materials such as polyvinylidene fluoride. These may be used alone or in combination of two or more. However, as shown in FIG. 1, when the positive electrode 21 and the negative electrode 22 are wound, it is preferable to use a styrene butadiene rubber or a fluorine rubber having high flexibility.

  The separator 23 separates the positive electrode 21 and the negative electrode 22 and allows lithium ions to pass through while preventing a short circuit of current due to contact between both electrodes. The separator 23 is composed of, for example, a porous film made of synthetic resin made of polytetrafluoroethylene, polypropylene, polyethylene, or the like, or a multi-hard film made of ceramic, and these two or more kinds of porous films are laminated. You may have the structure made. Among them, a porous film made of polyolefin is preferable because it is excellent in short-circuit preventing effect and can improve battery safety by a shutdown effect. In particular, polyethylene is preferable because a shutdown effect can be obtained within a range of 100 ° C. or more and 160 ° C. or less and the electrochemical stability is excellent. Polypropylene is also preferable, and other resins having chemical stability may be copolymerized with polyethylene or polypropylene, or may be blended.

  The separator 23 is impregnated with the above-described electrolytic solution as a liquid electrolyte. This is because the cycle characteristics are improved.

  In the secondary battery, when charged, for example, lithium ions are extracted from the positive electrode 21 and inserted in the negative electrode 22 through the electrolytic solution. On the other hand, when discharging is performed, for example, lithium ions are extracted from the negative electrode 22 and inserted in the positive electrode 21 through the electrolytic solution.

  This secondary battery is manufactured as follows, for example.

  First, for example, the positive electrode active material layer 21B is formed on both surfaces of the positive electrode current collector 21A to produce the positive electrode 21. In this case, a positive electrode mixture obtained by mixing a positive electrode active material powder, a conductive agent, and a binder is dispersed in a solvent to form a paste-like positive electrode mixture slurry, and the positive electrode mixture slurry is used as a positive electrode current collector. After applying to the body 21A and drying, compression molding is performed with a roll press. For example, the negative electrode 22 is manufactured by forming the negative electrode active material layer 22B on both surfaces of the negative electrode current collector 22A by the same manufacturing procedure as that of the positive electrode 21.

  Subsequently, the cathode lead 25 is attached by welding to the cathode current collector 21A, and the anode lead 26 is attached by welding to the anode current collector 22A. Subsequently, the positive electrode 21 and the negative electrode 22 are wound through the separator 23 to form the wound electrode body 20, and the tip of the positive electrode lead 25 is welded to the safety valve mechanism 15 and the tip of the negative electrode lead 26 is connected to the battery. After welding to the can 11, the wound electrode body 20 is housed inside the battery can 11 while being sandwiched between the pair of insulating plates 12 and 13. Subsequently, an electrolytic solution is injected into the battery can 11 and impregnated in the separator 23. Finally, the battery lid 14, the safety valve mechanism 15, and the heat sensitive resistance element 16 are caulked and fixed to the opening end of the battery can 11 via the gasket 17. Thereby, the secondary battery shown in FIGS. 1 and 2 is completed.

  According to this cylindrical secondary battery, when the capacity of the negative electrode 22 is expressed based on insertion and extraction of lithium, since the above-described electrolytic solution is provided, the decomposition reaction of the electrolytic solution is suppressed. . Therefore, cycle characteristics can be improved. Other effects relating to the secondary battery are the same as those described for the above-described electrolytic solution.

  Next, the second and third batteries will be described. Components that are the same as those of the first battery are denoted by the same reference numerals, and description thereof is omitted.

(Second battery)
The second battery has the same configuration, operation, and effect as the first battery except that the configuration of the negative electrode 22 is different, and is manufactured by the same procedure.

  The negative electrode 22 has a negative electrode active material layer 22B provided on both surfaces of a negative electrode current collector 22A, as in the first battery. The negative electrode active material layer 22B contains, for example, a material having silicon or tin as a constituent element as a negative electrode active material. Specifically, for example, it contains a silicon simple substance, an alloy or a compound, or a tin simple substance, an alloy or a compound, and may contain two or more of them.

  The negative electrode active material layer 22B is formed by using a vapor phase method, a liquid phase method, a thermal spraying method, a firing method, or two or more of these methods. The negative electrode active material layer 22B and the negative electrode current collector It is preferable that 22A is alloyed in at least a part of the interface. Specifically, the constituent element of the negative electrode current collector 22A may be diffused into the negative electrode active material layer 22B at the interface, or the constituent element of the negative electrode active material layer 22B may be diffused into the negative electrode current collector 22A. Alternatively, both constituent elements may be diffused with each other. This is because, during charging / discharging, breakage due to expansion and contraction of the negative electrode active material layer 22B is suppressed, and electronic conductivity between the negative electrode active material layer 22B and the negative electrode current collector 22A is improved.

  As the vapor phase method, for example, physical deposition method or chemical deposition method, specifically, vacuum vapor deposition method, sputtering method, ion plating method, laser ablation method, thermal chemical vapor deposition (CVD; Chemical Vapor Deposition) Or plasma chemical vapor deposition. As the liquid phase method, a known method such as electroplating or electroless plating can be used. The firing method is, for example, a method in which a particulate negative electrode active material is mixed with a binder, dispersed in a solvent, applied, and then heat-treated at a temperature higher than the melting point of the binder. A known method can also be used for the firing method, for example, an atmospheric firing method, a reactive firing method, or a hot press firing method.

(Third battery)
The third battery is a lithium metal secondary battery in which the capacity of the negative electrode 22 is expressed based on the precipitation and dissolution of lithium. This secondary battery has the same configuration as that of the first battery except that the negative electrode active material layer 22B is made of lithium metal, and is manufactured by the same procedure.

  This secondary battery uses lithium metal as a negative electrode active material, and can thereby obtain a high energy density. The negative electrode active material layer 22B may already be provided from the time of assembly, but may not be present at the time of assembly and may be constituted by lithium metal deposited during charging. Further, the negative electrode current collector 22A may be omitted by using the negative electrode active material layer 22B as a current collector.

  In this secondary battery, when charged, for example, lithium ions are released from the positive electrode 21 and deposited as lithium metal on the surface of the negative electrode current collector 22A through the electrolytic solution. On the other hand, when discharging is performed, for example, lithium metal is eluted from the negative electrode active material layer 22B as lithium ions and inserted into the positive electrode 21 through the electrolytic solution.

  According to this cylindrical secondary battery, when the capacity of the negative electrode 22 is expressed based on the precipitation and dissolution of lithium, since the above-described electrolytic solution is provided, cycle characteristics can be improved. Other effects relating to the secondary battery are the same as those of the first battery described above.

(4th battery)
FIG. 3 illustrates an exploded perspective configuration of the fourth battery. In this battery, a wound electrode body 30 to which a positive electrode lead 31 and a negative electrode lead 32 are attached is mainly housed in a film-shaped exterior member 40. The battery structure using the film-shaped exterior member 40 is called a laminate film type.

  For example, the positive electrode lead 31 and the negative electrode lead 32 are each led out in the same direction from the inside of the exterior member 40 toward the outside. The positive electrode lead 31 is made of, for example, a metal material such as aluminum. The negative electrode lead 32 is made of a metal material such as copper, nickel, or stainless steel, for example. Each metal material constituting the positive electrode lead 31 and the negative electrode lead 32 is, for example, a thin plate shape or a mesh shape.

  The exterior member 40 is made of, for example, a rectangular aluminum laminated film in which a nylon film, an aluminum foil, and a polyethylene film are bonded together in this order. In the exterior member 40, for example, a polyethylene film is opposed to the spirally wound electrode body 30, and each outer edge portion is in close contact with each other by fusion or an adhesive. An adhesive film 41 is inserted between the exterior member 40 and the positive electrode lead 31 and the negative electrode lead 32 to prevent intrusion of outside air. The adhesion film 41 is made of a material having adhesion to the positive electrode lead 31 and the negative electrode lead 32, for example, a polyolefin resin such as polyethylene, polypropylene, modified polyethylene, or modified polypropylene.

  The exterior member 40 may be constituted by a laminate film having another structure instead of the above-described three-layer aluminum laminate film, or may be constituted by a polymer film such as polypropylene or a metal film. May be.

  FIG. 4 shows a cross-sectional configuration along line IV-IV of the spirally wound electrode body 30 shown in FIG. The electrode winding body 30 is obtained by winding a positive electrode 33 and a negative electrode 34 after being laminated via a separator 35 and an electrolyte 36, and an outermost peripheral portion thereof is protected by a protective tape 37.

  The positive electrode 33 is obtained by providing a positive electrode active material layer 33B on both surfaces of a positive electrode current collector 33A. The negative electrode 34 is provided with a negative electrode active material layer 34B on both surfaces of a negative electrode current collector 34A, and the negative electrode active material layer 34B is disposed so as to face the positive electrode active material layer 33B. The configurations of the positive electrode current collector 33A, the positive electrode active material layer 33B, the negative electrode current collector 34A, the negative electrode active material layer 34B, and the separator 35 are the same as the positive electrode current collector 21A and the positive electrode active material in the first to third batteries described above. The configurations of the layer 21B, the negative electrode current collector 22A, the negative electrode active material layer 22B, and the separator 23 are the same.

  The electrolyte 36 includes the above-described electrolytic solution and a polymer compound that holds the electrolytic solution, and is in a so-called gel form. A gel electrolyte is preferable because high ion conductivity (for example, 1 mS / cm or more at room temperature) is obtained and liquid leakage is prevented.

  Examples of the polymer compound include polyacrylonitrile, polyvinylidene fluoride, a copolymer of polyvinylidene fluoride and polyhexafluoropyrene, polytetrafluoroethylene, polyhexafluoropropylene, polyethylene oxide, polypropylene oxide, polyphosphazene, poly Examples thereof include siloxane, polyvinyl acetate, polyvinyl alcohol, polymethyl methacrylate, polyacrylic acid, polymethacrylic acid, styrene-butadiene rubber, nitrile-butadiene rubber, polystyrene, and polycarbonate. These may be used alone, or a plurality of types may be mixed and used. In particular, from the viewpoint of electrochemical stability, it is preferable to use polyacrylonitrile, polyvinylidene fluoride, polyhexafluoropropylene, polyethylene oxide, or the like. The addition amount of the polymer compound in the electrolytic solution varies depending on the compatibility between the two, but is preferably 5% by mass or more and 50% by mass or less.

  The composition of the electrolytic solution is the same as the composition of the electrolytic solution in the first battery described above. However, the term “solvent” as used herein is a broad concept including not only a liquid solvent but also one having ion conductivity capable of dissociating an electrolyte salt. Accordingly, when a polymer compound having ion conductivity is used, the polymer compound is also included in the solvent. In particular, when a liquid solvent is used, it is preferable to use propylene carbonate. This is because swelling of the secondary battery is suppressed.

  Instead of the electrolyte 36 in which the electrolytic solution is held by the polymer compound, the electrolytic solution may be used as it is. In this case, the separator 35 is impregnated with the electrolytic solution.

  This secondary battery is manufactured by the following three types of manufacturing methods, for example.

  In the first manufacturing method, first, the positive electrode active material layer 33B is formed on both surfaces of the positive electrode current collector 33A by, for example, the same procedure as in the first battery manufacturing method, and the positive electrode 33 is manufactured. A negative electrode active material layer 34B is formed on both sides of the current collector 34A to produce a negative electrode 34. Then, after preparing the precursor solution containing electrolyte solution, a high molecular compound, and a solvent and apply | coating to the positive electrode 33 and the negative electrode 34, the solvent is volatilized and the gel electrolyte 36 is formed. Subsequently, the positive electrode lead 31 and the negative electrode lead 32 are attached to the positive electrode current collector 33A and the negative electrode current collector 34A, respectively. Subsequently, the positive electrode 33 and the negative electrode 34 provided with the electrolyte 36 are stacked via the separator 35 and then wound in the longitudinal direction, and a protective tape 37 is adhered to the outermost peripheral portion to form the wound electrode body 30. To do. Finally, for example, after the wound electrode body 30 is sandwiched between two film-shaped exterior members 40, the outer edge portions of the exterior member 40 are bonded to each other by heat fusion or the like, so that the wound electrode body 30 is Encapsulate. At that time, the adhesion film 41 is inserted between the positive electrode lead 31 and the negative electrode lead 32 and the exterior member 40. Thereby, the secondary battery shown in FIGS. 3 and 4 is completed.

  In the second manufacturing method, first, the positive electrode lead 31 and the negative electrode lead 32 are attached to the positive electrode 33 and the negative electrode 34, respectively, and then the positive electrode 33 and the negative electrode 34 are stacked and wound via the separator 35, and the outermost periphery is wound. A protective tape 37 is adhered to the part to form a wound body that is a precursor of the wound electrode body 30. Subsequently, after sandwiching the wound body between the two film-like exterior members 40, the remaining outer peripheral edge portion excluding the outer peripheral edge portion on one side is bonded by thermal fusion or the like to form a bag-like exterior member The wound body is accommodated inside 40. Subsequently, an electrolyte composition containing an electrolytic solution, a monomer that is a raw material of the polymer compound, a polymerization initiator, and other materials such as a polymerization inhibitor as necessary is prepared to form a bag-shaped exterior member. After injecting into the inside of 40, the opening part of the exterior member 40 is sealed by heat sealing or the like. Finally, the gel electrolyte 36 is formed by thermally polymerizing the monomer to obtain a polymer compound. Thereby, the secondary battery is completed.

  In the third manufacturing method, a wound body is formed by forming a wound body in the same manner as in the first manufacturing method described above, except that the separator 35 coated with the polymer compound on both sides is used first. 40 is housed inside. Examples of the polymer compound applied to the separator 35 include a polymer containing vinylidene fluoride as a component, that is, a homopolymer, a copolymer, or a multi-component copolymer. Specifically, polyvinylidene fluoride, binary copolymers containing vinylidene fluoride and hexafluoropropylene as components, and ternary copolymers containing vinylidene fluoride, hexafluoropropylene and chlorotrifluoroethylene as components. Such as coalescence. In addition, the high molecular compound may contain the other 1 type, or 2 or more types of high molecular compound with the polymer which uses the above-mentioned vinylidene fluoride as a component. Subsequently, after the electrolytic solution is prepared and injected into the exterior member 40, the opening of the exterior member 40 is sealed by heat fusion or the like. Finally, the exterior member 40 is heated while applying a load, and the separator 35 is brought into close contact with the positive electrode 33 and the negative electrode 34 through the polymer compound. As a result, the electrolytic solution is impregnated into the polymer compound, and the polymer compound is gelled to form the electrolyte 36. Thus, the secondary battery is completed.

  In the third manufacturing method, the swollenness of the secondary battery is suppressed as compared with the first manufacturing method. Further, in the third manufacturing method, compared with the second manufacturing method, there are hardly any monomers or solvents that are raw materials for the polymer compound remaining in the electrolyte 36, and the formation process of the polymer compound is well controlled. Therefore, sufficient adhesion is obtained between the positive electrode 33, the negative electrode 34, the separator 35, and the electrolyte 36.

  The operations and effects of the laminate film type secondary battery are the same as those of the first to third batteries.

  Specific examples of the present invention will be described in detail.

(Example 1-1)
Using artificial graphite as the negative electrode active material, the laminate film type secondary battery shown in FIGS. 3 and 4 was produced. At this time, a lithium ion secondary battery in which the capacity of the negative electrode 34 is expressed based on insertion and extraction of lithium was made.

First, the positive electrode 33 was produced. First, lithium carbonate (Li ₂ CO ₃ ) and cobalt carbonate (CoCO ₃ ) were mixed at a molar ratio of 0.5: 1, and then calcined in air at 900 ° C. for 5 hours to obtain a lithium cobalt composite oxide ( LiCoO ₂ ) was obtained. Subsequently, 91 parts by mass of lithium cobalt composite oxide powder as a positive electrode active material, 6 parts by mass of graphite as a conductive agent, and 3 parts by mass of polyvinylidene fluoride as a binder were mixed to form a positive electrode mixture. -Dispersed in methyl-2-pyrrolidone to obtain a paste-like positive electrode mixture slurry. Finally, the positive electrode mixture slurry was uniformly applied to both surfaces of the positive electrode current collector 33A made of a strip-shaped aluminum foil (12 μm thick), dried, and then compression-molded with a roll press to form the positive electrode active material layer 33B. Formed.

  Next, the negative electrode 34 was produced. First, 90 parts by mass of artificial graphite powder as a negative electrode active material and 10 parts by mass of polyvinylidene fluoride as a binder were mixed to form a negative electrode mixture, which was then dispersed in N-methyl-2-pyrrolidone and pasted. Negative electrode mixture slurry. Finally, the negative electrode mixture slurry was uniformly applied to both surfaces of the negative electrode current collector 34A made of a strip-shaped copper foil (15 μm thick), dried, and then compression-molded with a roll press to form the negative electrode active material layer 34B. Formed.

Next, as a solvent, ethylene carbonate (EC), diethyl carbonate (DEC), and a compound of chemical formula 6 (1) which is an organic cyclic silicon compound having the structure shown in chemical formula 3 (compound shown in chemical formula 4) Then, lithium hexafluorophosphate (LiPF ₆ ) was dissolved as an electrolyte salt to prepare an electrolytic solution. At this time, the mixing ratio of EC and DEC was 30:70 by weight, the content of the compound of chemical formula 6 (1) in the solvent was 0.01% by weight, and the concentration of the electrolyte salt in the electrolytic solution was 1 mol. / Kg. This “% by weight” is a unit when the entire solvent is 100% by weight, and the same applies hereinafter.

  Next, a secondary battery was assembled using the positive electrode 33 and the negative electrode 34. First, the positive electrode lead 31 made of aluminum was welded to one end of the positive electrode current collector 33A, and the negative electrode lead 32 made of nickel was welded to one end of the negative electrode current collector 34A. Subsequently, the positive electrode 33, the separator 35 made of a microporous polypropylene film (25 μm thick), and the negative electrode 34 are laminated in this order and wound many times in the longitudinal direction, and then the protective tape 37 made of an adhesive tape is used. The winding end part was fixed, and the wound body which is the precursor of the wound electrode body 30 was formed. Subsequently, an exterior member made of a laminate film having a three-layer configuration (total thickness of 100 μm) in which a nylon film (30 μm thickness), an aluminum foil (40 μm thickness), and an unstretched polypropylene film (30 μm thickness) are laminated from the outside. After sandwiching the wound body between 40, the outer edge portions except for one side were heat-sealed to accommodate the wound body in the bag-shaped exterior member 40. Subsequently, an electrolytic solution was injected into the inside through the opening of the exterior member 40 and the separator 35 was impregnated with the electrolytic solution to form the wound electrode body 30.

  Finally, the laminated film type secondary battery was completed by thermally sealing and sealing the opening of the exterior member 40 in a vacuum atmosphere.

(Examples 1-2 to 1-5)
The content of the compound of Chemical formula 6 (1) in the solvent is 1% by weight (Example 1-2), 2% by weight (Example 1-3), 5% by weight (Example 1-4), or 10% by weight. % (Example 1-5), except that the procedure was the same as Example 1-1.

(Example 1-6)
A procedure similar to that of Example 1-3 was performed except that the compound of the chemical formula 6 (1) was used in place of the compound of the chemical formula 6 (1) as the organic cyclic silicon compound having the structure shown in the chemical formula 3.

(Examples 1-7 to 1-12)
Vinylene carbonate (VC: Example 1-7), 4-fluoro-1,3-dioxolan-2-one (FEC: Example 1-8), trans-4,5-difluoro-1,3-dioxolane as a solvent 2-one (t-DFEC: Example 1-9), cis-4,5-difluoro-1,3-dioxolan-2-one (c-DFEC: Example 1-10), propene sultone (PRS: The procedure was the same as that of Example 1-3, except that Example 1-11) or sulfobenzoic anhydride (SBAH: Example 1-12) was added. At this time, the content of VC or the like in the solvent was 1% by weight.

(Examples 1-13 and 1-14)
The same procedure as in Examples 1-8 and 1-9 was performed, except that propylene carbonate (PC) was added as a solvent. At this time, the mixing ratio of EC, DEC, and PC was 20:70:10 by weight.

(Comparative Examples 1-1 to 1-3)
A procedure similar to that of Examples 1-1, 1-7, and 1-8 was performed, except that the compound of Chemical Formula 6 (1) was not added.

(Comparative Examples 1-4, 1-5)
Instead of the organic cyclic silicon compound having the structure shown in Chemical Formula 3 (compound of Chemical Formula 6 (1)), the organic chain silicon compound shown in Chemical Formula 29 (Comparative Example 1-4), or the organic material shown in Chemical Formula 30 A procedure similar to that of Example 1-2 was performed, except that a chain silicon compound (Comparative Example 1-5) was used.

  When the cycle characteristics of the secondary batteries of Examples 1-1 to 1-14 and Comparative examples 1-1 to 1-5 were examined, the results shown in Table 1 were obtained.

  When investigating cycle characteristics, charge and discharge for 2 cycles in an atmosphere at 23 ° C. to measure discharge capacity, and then repeatedly charge and discharge in the same atmosphere until the total number of cycles reaches 100 cycles to measure discharge capacity. After that, the discharge capacity retention ratio (%) = (discharge capacity at the 100th cycle / discharge capacity at the second cycle) × 100 was calculated. As charge / discharge conditions for one cycle, the battery was charged at a constant current of 0.2C until the battery voltage reached 4.2V, and then discharged at a constant current of 0.2C until the battery voltage reached 2.5V. This “0.2 C” is a current value at which the theoretical capacity can be discharged in 5 hours.

  The procedure and conditions for examining the cycle characteristics described above are the same for the series of examples and comparative examples described below.

  As shown in Table 1, in Examples 1-1 to 1-6 in which the solvent contains a compound of Chemical Formula 6 (1) or Chemical Formula 6 (12), the discharge capacity is higher than that of Comparative Example 1-1 that does not contain them. The maintenance rate became high. This result shows that when the solvent contains a compound of Chemical Formula 6 (1) or Chemical Formula 6 (12), the chemical stability of the electrolytic solution is improved, so that the electrolytic solution is not easily decomposed even after repeated charge and discharge. Represents. In this case, the discharge capacity retention rate is the same between Example 1-3 in which the solvent contains the compound of Chemical Formula 6 (1) and Example 1-6 in which the compound of Chemical Formula 6 (12) is contained. It became about. In particular, when the content of the compound of chemical formula 6 (1) in the solvent is less than 0.01% by weight or more than 10% by weight, the discharge capacity retention rate is significantly reduced. In the latter case, the capacity is also greatly reduced. Showed a tendency to

  From these facts, in the secondary battery of the present invention, when the negative electrode 34 contains artificial graphite as the negative electrode active material, the solvent of the electrolytic solution contains an organic cyclic silicon compound having the structure shown in Chemical Formula 3, It was confirmed that the cycle characteristics were improved without depending on the type of the organic cyclic silicon compound. In particular, if the content of the organic cyclic silicon compound in the solvent is 0.01 wt% or more and 10 wt% or less, good cycle characteristics can be obtained, 0.01 wt% or more and 5 wt% or less, and further 1 wt% or more. It was also confirmed that the cycle characteristics were further improved if it was 2% by weight or less.

  Moreover, in Examples 1-7 to 1-12 in which the solvent contains VC or the like, the discharge capacity retention ratio was higher than that in Example 1-3 not containing them. In this case, when comparing between FEC, t-DFEC and c-DFEC, the discharge capacity maintenance rate tends to be higher when t-DFEC or c-DFEC is contained than when FEC is contained. It was. Of course, in Examples 1-7 and 1-8 in which the solvent contains the compound of Chemical Formula 6 (1), the discharge capacity retention rate was higher than in Comparative Examples 1-2 and 1-3 not containing the compound.

  Therefore, in the secondary battery described above, if the solvent contains a cyclic carbonate having an unsaturated bond, a cyclic carbonate having a halogen shown in Chemical formula 16, sultone or an acid anhydride, the cycle characteristics are further improved. Confirmed to do. In particular, when the cyclic carbonate having halogen shown in Chemical formula 16 was used, it was confirmed that the cycle characteristics improved as the number of halogens increased.

  In addition, although the result in the case where the solvent contains a chain carbonate having a halogen shown in Chemical formula 15 is not shown here, the chain carbonate having a halogen shown in Chemical formula 15 does not have the halogen shown in Chemical formula 16. Since it has the same function as the cyclic carbonate having, it is clear that the same result can be obtained even when the chain carbonate having halogen shown in Chemical formula 15 is contained. The same applies to the case where the chain carbonate having a halogen shown in Chemical Formula 15 and the cyclic carbonate having a halogen shown in Chemical Formula 16 are mixed, or in the case where two or more of them are mixed. is there.

  Moreover, in Examples 1-13 and 1-14 in which the solvent contains PC, discharge capacity retention ratios equal to or higher than those in Examples 1-8 and 1-9 not containing PC were obtained.

  From this, it was confirmed that in the secondary battery described above, the cycle characteristics were improved even when the solvent contained propylene carbonate.

  Moreover, in Example 1-2 containing the organic cyclic silicon compound (compound of the chemical formula 6 (1)) having the structure shown in chemical formula 3, the organic chain silicon compound shown in the chemical formula 29 or chemical formula 30 is contained. The discharge capacity retention ratio was higher than those of Comparative Examples 1-4 and 1-5. In this case, as is clear from the comparison with Comparative Example 1-1 in which the solvent contains neither the organic cyclic silicon compound nor the organic chain silicon compound, the discharge capacity retention rate is increased when the solvent contains the organic chain silicon compound. Although it decreased, the discharge capacity retention rate increased when the organocyclic silicon compound was contained.

  From these, it was confirmed that in the secondary battery described above, the organic cyclic silicon compound having the structure shown in Chemical Formula 3 is more advantageous than the organic chain silicon compound in improving the cycle characteristics.

(Examples 2-1 and 2-2)
Except for adding lithium tetrafluoroborate (LiBF ₄ : Example 2-1) or the compound of Chemical Formula 22 (6) (Example 2-2) shown in Chemical Formula 19 as the electrolyte salt, The same procedure as in Example 1-3 was performed. At this time, the concentration of LiPF ₆ in the electrolytic solution was 0.9 mol / kg, and the concentration of LiBF _{4 and the} like was 0.1 mol / kg.

(Comparative Example 2)
The same procedure as in Example 2-2 was performed, except that the compound of Chemical Formula 6 (1) was not added.

  When the cycle characteristics of the secondary batteries of Examples 2-1 and 2-2 and Comparative Example 2 were examined, the results shown in Table 2 were obtained.

  As shown in Table 2, in Examples 2-1 and 2-2 in which the electrolyte salt contains lithium tetrafluoroborate or a compound of Chemical Formula 22 (6), compared to Example 1-3 that does not contain them. The discharge capacity maintenance rate increased. Of course, in Examples 2-1 and 2-2 in which the solvent contains the compound of Chemical formula 6 (1), the discharge capacity retention rate was higher than those in Comparative Examples 1-1 and 2 that did not contain the compound.

  From these facts, it was confirmed that in the secondary battery described above, the cycle characteristics were further improved if the electrolyte salt contained lithium tetrafluoroborate or the compound shown in Chemical formula 19.

  Here, the electrolyte salt is at least one selected from the group consisting of lithium perchlorate and lithium hexafluoroarsenate, at least one selected from the group consisting of the compounds shown in Chemical formula 20 and Chemical formula 21, or Chemical formula 25 Although the result in the case of containing at least one of the group consisting of the compounds shown in Chemical Formula 26 and Chemical Formula 27 is not shown, lithium perchlorate has the same function as lithium tetrafluoroborate etc. Thus, it is clear that similar results can be obtained even when lithium perchlorate or the like is contained. The same applies to the case where two or more kinds of the above electrolyte salts are mixed.

(Examples 3-1 to 3-14)
A procedure similar to that of Examples 1-1 to 1-14 was performed except that the negative electrode active material layer 34B was formed using silicon instead of artificial graphite as the negative electrode active material. In the case of forming the negative electrode active material layer 34B, silicon was deposited on the negative electrode current collector 34A by an electron beam evaporation method.

(Comparative Examples 3-1 to 3-5)
The same procedure as Comparative Examples 1-1 to 1-5 was performed except that the negative electrode active material layer 34B was formed using silicon in the same manner as in Examples 3-1 to 3-14.

  When the cycle characteristics of the secondary batteries of Examples 3-1 to 3-14 and Comparative examples 3-1 to 3-5 were examined, the results shown in Table 3 were obtained.

  As shown in Table 3, when the negative electrode active material layer 34B was formed using silicon as the negative electrode active material, the results almost the same as the results shown in Table 1 were obtained. That is, in Examples 3-1 to 3-14 in which the solvent contains a compound of Chemical Formula 6 (1) or Chemical Formula 6 (12), the discharge capacity retention rate is higher than that of Comparative Examples 3-1 to 3-5 not containing them. Became high. In this case, when the content of the compound of Chemical formula 6 (1) in the solvent was 0.01 wt% or more and 10 wt% or less, a high discharge capacity retention rate was obtained. Moreover, when the solvent contains VC or the like, the discharge capacity retention rate was higher, and when the solvent contained PC, a high discharge capacity retention rate was obtained. Furthermore, in the case where the solvent contains an organic cyclic silicon compound (compound of chemical formula (1)), the discharge capacity retention rate was higher than that in the case of containing the organic chain silicon compound shown in chemical formula 29 and chemical formula 30. .

  From these facts, in the secondary battery of the present invention, even when the negative electrode 34 contains silicon as the negative electrode active material, the solvent of the electrolytic solution contains the organic cyclic silicon compound having the structure shown in Chemical Formula 3, It was confirmed that the cycle characteristics were improved as in the case of including artificial graphite. In particular, when the content of the organic cyclic silicon compound in the solvent is 0.01 wt% or more and 10 wt% or less, good cycle characteristics can be obtained, and 1 wt% or more and 10 wt% or less, and further 2 wt% or more and 10 wt%. It was also confirmed that the cycle characteristics were further improved if it was less than or equal to%.

(Examples 4-1 and 4-2)
The same procedures as in Examples 2-1 and 2-2 were performed except that the negative electrode active material layer 34B was formed using silicon in the same manner as in Examples 3-1 to 3-14.

(Comparative Example 4)
The same procedure as in Comparative Example 2 was performed except that the negative electrode active material layer 34B was formed using silicon in the same manner as in Examples 3-1 to 3-14.

  When the cycle characteristics of the secondary batteries of Examples 4-1 and 4-2 and Comparative Example 4 were examined, the results shown in Table 4 were obtained.

  As shown in Table 4, when silicon was included as the negative electrode active material, the same results as those shown in Table 2 were obtained. That is, in Examples 4-1 and 4-2 in which the electrolyte salt contains lithium tetrafluoroborate and the like, the discharge capacity retention rate is higher than those in Example 3-3 and Comparative Examples 3-1 and 4 that do not contain them. It became high.

  Therefore, in the secondary battery described above, even when the negative electrode 34 contains silicon as the negative electrode active material, if the electrolyte salt contains lithium tetrafluoroborate or the compound shown in Chemical formula 19, the cycle characteristics are more improved. It was confirmed to improve.

  In addition, although the result when the solvent contains the compound shown in Chemical formula 5 as the organic cyclic silicon compound having the structure shown in Chemical formula 3 is not shown here, the compound shown in Chemical formula 5 is the compound shown in Chemical formula 4. It is clear that the same result can be obtained even when the compound shown in Chemical formula 5 is contained. The same applies to the case where the compounds shown in Chemical Formula 4 and Chemical Formula 5 are mixed.

  From the results shown in Tables 1 to 4, in the secondary battery of the present invention, the organic cyclic silicon compound having the structure shown in Chemical Formula 3 is used regardless of the type of the negative electrode active material and the composition of the solvent. It was confirmed that the cycle characteristics were improved by the inclusion. In this case, when silicon was used as the negative electrode active material, the rate of increase in the discharge capacity retention rate was greater when silicon was used. This result suggests that the use of silicon, which is advantageous for increasing the capacity as the negative electrode active material, makes the electrolyte solution more easily decomposed than when a carbon material is used. It is done.

  The present invention has been described with reference to the embodiments and examples. However, the present invention is not limited to the embodiments described in the above embodiments and examples, and various modifications can be made. For example, the usage application of the electrolytic solution of the present invention is not necessarily limited to a battery, but may be an electrochemical device other than a battery. Other applications include, for example, capacitors.

  In the above-described embodiments and examples, the case where the electrolyte solution or the gel electrolyte in which the electrolyte solution is held in a polymer compound is used as the electrolyte of the battery of the present invention has been described. May be used. Other electrolytes include, for example, a mixture of an ion conductive inorganic compound such as ion conductive ceramics, ion conductive glass or ionic crystal and an electrolyte, or a mixture of another inorganic compound and an electrolyte. Or a mixture of these inorganic compounds and a gel electrolyte.

  In the above-described embodiments and examples, the battery of the present invention includes a lithium ion secondary battery in which the capacity of the negative electrode is expressed based on insertion and extraction of lithium, and the capacity of the negative electrode is used for precipitation and dissolution of lithium. Although the lithium metal secondary battery represented based on was demonstrated, it is not necessarily restricted to this. In the battery of the present invention, the negative electrode material capable of occluding and releasing lithium has a smaller charge capacity than that of the positive electrode, so that the negative electrode capacity is based on the storage and release of lithium and the deposition of lithium and The present invention can be similarly applied to a secondary battery including a capacity based on melting and represented by the sum of the capacities.

  In the above-described embodiments and examples, the case where lithium is used as the electrode reactant has been described. However, a group 1A element or magnesium in other short-period periodic table such as sodium (Na) or potassium (K) You may use 2A group elements, such as calcium (Ca), and other light metals, such as aluminum. Also in this case, the negative electrode material described in the above embodiment can be used as the negative electrode active material.

  Further, in the above-described embodiment or example, the battery of the present invention has been described by taking the case where the battery structure is a cylindrical type and a laminate film type, and the case where the battery element has a winding structure as an example, The battery of the present invention can be similarly applied to a case where the battery has another battery structure such as a square shape, a coin shape or a button shape, or a case where the battery element has another structure such as a laminated structure. Further, the battery of the present invention is not limited to the secondary battery, but can be similarly applied to other types of batteries such as a primary battery.

  Moreover, in the said embodiment and Example, the appropriate range derived | led-out from the result of the Example was demonstrated about content of the organic cyclic silicon compound which has the structure shown in Chemical formula 3 in the electrolyte solution or battery of this invention. However, the explanation does not completely deny the possibility that the content is outside the above range. In other words, the appropriate range described above is a particularly preferable range for obtaining the effect of the present invention, and the content may be slightly deviated from the above range as long as the effect of the present invention is obtained.

It is sectional drawing showing the structure of the 1st battery using the electrolyte solution which concerns on one embodiment of this invention. It is sectional drawing which expands and represents a part of winding electrode body shown in FIG. It is a disassembled perspective view showing the structure of the 4th battery using the electrolyte solution which concerns on one embodiment of this invention. It is sectional drawing showing the structure along the IV-IV line of the wound electrode body shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Battery can, 12, 13 ... Insulation board, 14 ... Battery cover, 15 ... Safety valve mechanism, 15A ... Disc board, 16 ... Heat sensitive resistance element, 17 ... Gasket, 20, 30 ... Winding electrode body, 21, 33 ... Positive electrode, 21A, 33A ... Positive electrode current collector, 21B, 33B ... Positive electrode active material layer, 22, 34 ... Negative electrode, 22A, 34A ... Negative electrode current collector, 22B, 34B ... Negative electrode active material layer, 23, 35 ... Separator 24, center pin, 25, 31 ... positive electrode lead, 26, 32 ... negative electrode lead, 36 ... electrolyte, 37 ... protective tape, 40 ... exterior member, 41 ... adhesion film.

Claims (27)

An electrolyte solution comprising a solvent containing an organic cyclic silicon compound having a structure represented by Chemical Formula 1.

(R1 and R2 are an alkyl group having 1 to 4 carbon atoms, an alkenyl group or aryl group having 2 to 4 carbon atoms, or a halogenated group thereof.) 2. The electrolytic solution according to claim 1, wherein the organic cyclic silicon compound having the structure shown in Chemical Formula 1 is at least one of the compounds represented by Chemical Formula 2 and Chemical Formula 3. 3.

(R11 and R12 are an alkyl group having 1 to 4 carbon atoms, an alkenyl group or aryl group having 2 to 4 carbon atoms, or a halogenated group thereof. R13 is an alkylene group having 2 to 4 carbon atoms, These are alkenylene groups having 2 to 4 carbon atoms, divalent groups having an aromatic ring, halogenated groups thereof, or derivatives thereof.

(R21 to R24 are an alkyl group having 1 to 4 carbon atoms, an alkenyl group or aryl group having 2 to 4 carbon atoms, or a halogenated group thereof. R25 and R26 are alkylene having 1 to 4 carbon atoms. Group, an alkenylene group having 2 to 4 carbon atoms, a divalent group having an aromatic ring, or a halogenated group thereof.)   2. The electrolytic solution according to claim 1, wherein the content of the organic cyclic silicon compound having the structure shown in Chemical Formula 1 in the solvent is 0.01 wt% or more and 10 wt% or less.   The electrolytic solution according to claim 1, wherein the solvent contains a cyclic carbonate having an unsaturated bond. The solvent contains at least one selected from the group consisting of a chain carbonate having a halogen represented by Chemical Formula 4 and a cyclic carbonate having a halogen represented by Chemical Formula 5. Electrolyte of description.

(R31 to R36 are a hydrogen group, a halogen group, an alkyl group or a halogenated alkyl group, and at least one of them is a halogen group or a halogenated alkyl group.)

(R41 to R44 are a hydrogen group, a halogen group, an alkyl group or a halogenated alkyl group, and at least one of them is a halogen group or a halogenated alkyl group.) The chain carbonate having a halogen shown in Chemical Formula 4 is at least one of bis (fluoromethyl) carbonate and fluoromethyl methyl carbonate,
The cyclic carbonate having a halogen shown in Chemical Formula 5 is at least one of 4-fluoro-1,3-dioxolan-2-one and 4,5-difluoro-1,3-dioxolan-2-one. The electrolyte solution according to claim 5, wherein the electrolyte solution is present.   The electrolytic solution according to claim 1, wherein the solvent contains sultone.   The electrolytic solution according to claim 1, wherein the solvent contains an acid anhydride. At least one selected from the group consisting of lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium perchlorate (LiClO ₄ ), and lithium hexafluoroarsenate (LiAsF ₆ ) The electrolyte solution according to claim 1, comprising an electrolyte salt containing 2. The electrolytic solution according to claim 1, comprising an electrolyte salt containing at least one member selected from the group consisting of the compounds represented by Chemical Formula 6, Chemical Formula 7 and Chemical Formula 8:

(X51 is a 1A group element or 2A group element in the short periodic table, or aluminum (Al). M51 is a transition metal, or a 3B group element, 4B group element, or 5B group element in the short period type periodic table. R51 is a halogen group, Y51 is —OC—R52—CO—, —OC—CR53 ₂ — or —OC—CO—, wherein R52 is an alkylene group, a halogenated alkylene group, an arylene group or a halogenated group. R53 is an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group, wherein a5 is an integer of 1 to 4, b5 is an integer of 0, 2 or 4, and c5 , D5, m5 and n5 are integers of 1 to 3.)

(X61 is a group 1A element or a group 2A element in the short period type periodic table. M61 is a transition metal, or a group 3B element, a group 4B element, or a group 5B element in the short period type periodic table. Y61 is —OC—. _{(CR61 2) b6 -CO -,} - R63 2 C- (CR62 2) c6 -CO -, - R63 2 C- (CR62 2) c6 -CR63 2 -, - R63 2 C- (CR62 2) c6 -SO ₂ —, —O ₂ S— (CR62 ₂ ) _d6 —SO ₂ — or —OC— (CR62 ₂ ) _d6 —SO ₂ —, wherein R61 and R63 are hydrogen, alkyl, halogen, or halogenated An alkyl group, at least one of which is a halogen group or a halogenated alkyl group, and R62 is a hydrogen group, an alkyl group, a halogen group or a halogenated alkyl group. A6, e6 and n6 are integers of 1 or 2, b6 and d6 are integers of 1 to 4, c6 is an integer of 0 to 4, and f6 and m6 are integers of 1 to 3. )

(X71 is a group 1A element or a group 2A element in the short period type periodic table. M71 is a transition metal, or a group 3B element, a group 4B element, or a group 5B element in the short period type periodic table. Rf is a fluorinated alkyl. Or a fluorinated aryl group, each having 1 to 10 carbon atoms, Y71 is —OC— (CR71 ₂ ) _d7 —CO—, —R72 ₂ C— (CR71 ₂ ) _d7 —CO—, —R72 _{2 C- (CR71 2) d7 -CR72} 2 -, - R72 2 C- (CR71 2) d7 -SO 2 -, - O 2 S- (CR71 2) e7 -SO 2 - or -OC- (CR71 _{2) e7} -SO ₂ -. is, however, R71 is a hydrogen group, an alkyl group, is .R72 is the halogen group or the halogenated alkyl group be a hydrogen group, an alkyl group, a halogen group or a halogenated alkyl group At least one of them is a halogen group or a halogenated alkyl group, wherein a7, f7 and n7 are integers of 1 or 2, b7, c7 and e7 are integers of 1 to 4, and d7 is 0 to 0. 4 and g7 and m7 are integers of 1 to 3.) The compound represented by Chemical Formula 6 is at least one of the group consisting of compounds represented by Chemical Formula 9, and the compound represented by Chemical Formula 7 is one of the groups consisting of compounds represented by Chemical Formula 10 The electrolytic solution according to claim 10, wherein the compound is at least one compound and the compound represented by Chemical Formula 8 is a compound represented by Chemical Formula 11:

2. The electrolytic solution according to claim 1, comprising an electrolyte salt containing at least one member selected from the group consisting of compounds represented by chemical formulas 12, 13 and 14.

(M and n are integers of 1 or more.)

(R81 is a linear or branched perfluoroalkylene group having 2 to 4 carbon atoms.)

(P, q and r are integers of 1 or more.) A battery comprising an electrolyte solution together with a positive electrode and a negative electrode,
The battery includes a solvent containing an organic cyclic silicon compound having a structure represented by Chemical Formula 15.

(R1 and R2 are an alkyl group having 1 to 4 carbon atoms, an alkenyl group or aryl group having 2 to 4 carbon atoms, or a halogenated group thereof.) The battery according to claim 13, wherein the organocyclic silicon compound having the structure shown in Chemical Formula 15 is at least one of the compounds represented by Chemical Formula 16 and Chemical Formula 17.

(R11 and R12 are an alkyl group having 1 to 4 carbon atoms, an alkenyl group or aryl group having 2 to 4 carbon atoms, or a halogenated group thereof. R13 is an alkylene group having 2 to 4 carbon atoms, These are alkenylene groups having 2 to 4 carbon atoms, divalent groups having an aromatic ring, halogenated groups thereof, or derivatives thereof.

(R21 to R24 are an alkyl group having 1 to 4 carbon atoms, an alkenyl group or aryl group having 2 to 4 carbon atoms, or a halogenated group thereof. R25 and R26 are alkylene having 1 to 4 carbon atoms. Group, an alkenylene group having 2 to 4 carbon atoms, a divalent group having an aromatic ring, or a halogenated group thereof.)   14. The battery according to claim 13, wherein the content of the organic cyclic silicon compound having the structure shown in Chemical Formula 15 in the solvent is 0.01 wt% or more and 10 wt% or less.   The battery according to claim 13, wherein the solvent contains a cyclic ester carbonate having an unsaturated bond. 14. The solvent contains at least one selected from the group consisting of a chain carbonate having a halogen represented by Chemical Formula 18 and a cyclic carbonate having a halogen represented by Chemical Formula 19. The battery described.

(R31 to R36 are a hydrogen group, a halogen group, an alkyl group or a halogenated alkyl group, and at least one of them is a halogen group or a halogenated alkyl group.)

(R41 to R44 are a hydrogen group, a halogen group, an alkyl group or a halogenated alkyl group, and at least one of them is a halogen group or a halogenated alkyl group.) The chain carbonate having a halogen shown in Chemical Formula 18 is at least one of bis (fluoromethyl) carbonate and fluoromethylmethyl carbonate,
The halogenated cyclic ester carbonate represented by Chemical Formula 19 is at least one of 4-fluoro-1,3-dioxolan-2-one and 4,5-difluoro-1,3-dioxolan-2-one. The battery according to claim 17, which is provided.   The battery according to claim 13, wherein the solvent contains sultone.   The battery according to claim 13, wherein the solvent contains an acid anhydride.   14. An electrolyte salt comprising at least one member selected from the group consisting of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, and lithium hexafluoroarsenate. Battery. 14. The battery according to claim 13, comprising an electrolyte salt containing at least one member selected from the group consisting of compounds represented by chemical formula 20, chemical formula 21 and chemical formula 22:

(X51 is a 1A group element or 2A group element or aluminum in the short period type periodic table. M51 is a transition metal, or a 3B group element, 4B group element or 5B group element in the short period type periodic table. R51 is R51. Y51 is —OC—R52—CO—, —OC—CR53 ₂ — or —OC—CO—, wherein R52 is an alkylene group, a halogenated alkylene group, an arylene group or a halogenated arylene group. R53 is an alkyl group, a halogenated alkyl group, an aryl group or a halogenated aryl group, wherein a5 is an integer of 1 to 4, b5 is an integer of 0, 2 or 4, c5, d5, m5 and n5 are integers of 1 to 3.)

(X61 is a group 1A element or a group 2A element in the short period type periodic table. M61 is a transition metal, or a group 3B element, a group 4B element, or a group 5B element in the short period type periodic table. Y61 is —OC—. _{(CR61 2) b6 -CO -,} - R63 2 C- (CR62 2) c6 -CO -, - R63 2 C- (CR62 2) c6 -CR63 2 -, - R63 2 C- (CR62 2) c6 -SO ₂ —, —O ₂ S— (CR62 ₂ ) _d6 —SO ₂ — or —OC— (CR62 ₂ ) _d6 —SO ₂ —, wherein R61 and R63 are hydrogen, alkyl, halogen, or halogenated An alkyl group, at least one of which is a halogen group or a halogenated alkyl group, and R62 is a hydrogen group, an alkyl group, a halogen group or a halogenated alkyl group. A6, e6 and n6 are integers of 1 or 2, b6 and d6 are integers of 1 to 4, c6 is an integer of 0 to 4, and f6 and m6 are integers of 1 to 3. )

(X71 is a group 1A element or a group 2A element in the short period type periodic table. M71 is a transition metal, or a group 3B element, a group 4B element, or a group 5B element in the short period type periodic table. Rf is a fluorinated alkyl. Or a fluorinated aryl group, each having 1 to 10 carbon atoms, Y71 is —OC— (CR71 ₂ ) _d7 —CO—, —R72 ₂ C— (CR71 ₂ ) _d7 —CO—, —R72 _{2 C- (CR71 2) d7 -CR72} 2 -, - R72 2 C- (CR71 2) d7 -SO 2 -, - O 2 S- (CR71 2) e7 -SO 2 - or -OC- (CR71 _{2) e7} -SO ₂ -. is, however, R71 is a hydrogen group, an alkyl group, is .R72 is the halogen group or the halogenated alkyl group be a hydrogen group, an alkyl group, a halogen group or a halogenated alkyl group At least one of them is a halogen group or a halogenated alkyl group, wherein a7, f7 and n7 are integers of 1 or 2, b7, c7 and e7 are integers of 1 to 4, and d7 is 0 to 0. 4 and g7 and m7 are integers of 1 to 3.) The compound shown in Chemical Formula 20 is at least one of the group consisting of compounds represented by Chemical Formula 23, and the compound shown in Chemical Formula 21 is in the group consisting of compounds represented by Chemical Formula 24. 23. The battery according to claim 22, wherein the compound represented by Chemical Formula 22 is at least one compound and is represented by Chemical Formula 25.

The battery according to claim 13, comprising an electrolyte salt containing at least one member selected from the group consisting of compounds represented by chemical formulas 26, 27, and 28.

(M and n are integers of 1 or more.)

(R81 is a linear or branched perfluoroalkylene group having 2 to 4 carbon atoms.)

(P, q and r are integers of 1 or more.)   The negative electrode is a negative electrode active material containing a carbon material, lithium metal (Li), or a material that can occlude and release lithium and has at least one of a metal element and a semi-metal element. The battery according to claim 13, comprising:   The negative electrode includes a negative electrode active material containing at least one selected from the group consisting of a simple substance, an alloy and a compound of silicon (Si), and a simple substance, an alloy and a compound of tin (Sn). 13. The battery according to 13. The negative electrode has a negative electrode active material layer on a negative electrode current collector,
The battery according to claim 13, wherein the negative electrode active material layer is formed by at least one method selected from the group consisting of a vapor phase method, a liquid phase method, and a firing method.

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