JP2013140786A - Method for manufacturing electrochemical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for simply manufacturing an electrochemical device without deteriorating device performances, in an electrochemical device typified by a lithium ion secondary battery including a gel electrolyte.SOLUTION: In a method for manufacturing an electrochemical device, an electrolyte containing a gelatinizer capable of forming a phase transition type gel which is gelatinous at 25°C and converted to sol when heated is used. The method for manufacturing an electrochemical device includes a step of injecting a solution or a fluid dispersion containing the electrolyte into an electrochemical device structure and then removing at least a part of a solvent contained in the solution or the fluid dispersion.

Description

  The present invention relates to a method for manufacturing an electrochemical device.

With the recent development of electronic technology and increasing interest in environmental technology, various electrochemical devices are used. In particular, there are many requests for energy saving, and expectations for what can contribute to it are increasing. For example, a solar cell is mentioned as a power generation device, and a secondary battery, a capacitor, a capacitor, etc. are mentioned as an electrical storage device.
By the way, these electrochemical devices are used over a long period of several to several tens of years, and in addition to high efficiency and low cost, long life (high durability) and high safety are also required.

A typical lithium ion secondary battery as an electricity storage device generally has a configuration in which a positive electrode and a negative electrode mainly composed of an active material capable of inserting and extracting lithium are arranged via a separator. In a lithium ion secondary battery, the positive electrode is LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ or the like as a positive electrode active material, carbon black, graphite, or the like as a conductive agent, polyvinylidene fluoride as a binder, latex, rubber, or the like Is mixed with a positive electrode current collector made of aluminum or the like. The negative electrode is formed by coating a negative electrode mixture made of copper or the like with a negative electrode mixture in which coke, graphite or the like as a negative electrode active material and polyvinylidene fluoride, latex, rubber or the like as a binder are mixed. The The separator is made of porous polyolefin or the like, and its thickness is very thin, from several μm to several hundred μm. The positive electrode, the negative electrode, and the separator are impregnated with an electrolytic solution in the battery. Examples of the electrolytic solution include an electrolytic solution in which a lithium salt such as LiPF ₆ or LiBF ₄ is dissolved in an aprotic solvent such as propylene carbonate or ethylene carbonate, or a polymer such as polyethylene oxide.

  By the way, at present, lithium ion secondary batteries are mainly used as rechargeable batteries for portable devices (see, for example, Patent Document 1), and recently, their use as rechargeable batteries for hybrid vehicles and electric vehicles has also become widespread. ing. Here, when a lithium ion secondary battery is used for automobiles, higher safety and long-term durability are required as compared with those for portable devices. Recently, polymer electrolytes and gel electrolytes have attracted attention as electrolyte solutions for ion secondary batteries because they can be used in various cell shapes and module shapes in addition to their performance (for example, Patent Document 2 and Patent Documents). 3).

JP 2009-087648 A JP 2008-159596 A International Publication No. 2007/083843

  However, since conventional polymer electrolytes and gel electrolytes are solid at room temperature, it is possible to produce batteries with stable performance using these electrolytes in the same manner as when liquid electrolytes are used. Have difficulty. Therefore, various methods for accommodating these electrolytes in the battery have been studied in order to obtain a battery with stable performance. For example, a method of injecting a polymer or gel precursor into a battery structure and polymerizing the polymer or gel in-situ therein to form a polymer or gel, previously preparing a polymer or gel film, and other battery members And a method of producing a battery by stacking, and a method of drying a polymer electrolyte or gel electrolyte solution after applying it to a separator or an electrode.

  However, when using, for example, an in-situ method, it is necessary to uniformly polymerize the precursor in the battery structure, and further, by-products that adversely affect battery performance during polymerization are generated, polymerization raw materials remain, It is necessary to prevent a large volume change from occurring. Moreover, in the method of producing a film | membrane previously, it is necessary to fully adhere | attach a film | membrane and another member. In addition, the method of coating greatly increases the battery manufacturing process. Furthermore, in these methods, it is necessary to employ a polymer electrolyte or gel electrolyte suitable for the conditions accommodated in the battery rather than adopting an electrolyte that obtains excellent battery characteristics. It is difficult to achieve both battery fabrication methods. In particular, the larger the battery capacity or battery size, the more the polymer, gelling agent, and electrolyte are localized in the battery, and the unevenness of the concentration is likely to occur. Is very laborious.

  Therefore, the present invention has been made in view of the above circumstances, and in an electrochemical device typified by a lithium ion secondary battery using a gel electrolyte, the device performance is not degraded and the electrochemical device is simple. An object of the present invention is to provide a device manufacturing method.

  In order to achieve the above object, the present inventors have studied various processes for producing electrochemical devices using various gel electrolytes. As a result, a phase transition type gel was used as an electrolytic solution, and the electrolytic solution was used as an electrochemical device structure. After injecting into the body, through the process of removing at least a part of the solvent contained in the electrolytic solution, it was found that an electrochemical device having excellent electrochemical device characteristics can be easily formed, and the present invention has been completed. .

That is, the present invention is as follows.
[1] A method for producing an electrochemical device using an electrolytic solution containing a gelling agent that is gel-like at 25 ° C. and can form a phase transition-type gel that is heated to form a sol, the solution containing the electrolytic solution Alternatively, a method for producing an electrochemical device comprising a step of removing at least a part of a solvent contained in the solution or dispersion after injecting the dispersion into the electrochemical device structure.
[2] The method for producing an electrochemical device according to [1] or [2], wherein the solvent to be removed includes a solvent having a boiling point of 200 ° C. or lower.
[3] The method for producing an electrochemical device according to any one of [1] to [3], wherein the solvent to be removed includes at least one of a chain carbonate solvent and a nitrile solvent.
[4] The method for producing an electrochemical device according to any one of [1] to [3], wherein the solution or dispersion is a liquid in which an electrolyte and the gelling agent are dissolved in a solvent. .
[5] The method for producing an electrochemical device according to any one of [1] to [3], wherein the solution or dispersion is a gelled liquid containing a solvent, an electrolyte, and a gelling agent.
[6] The electrochemical device according to any one of [1] to [3], wherein the solution or dispersion is a slurry liquid in which an electrolyte is dissolved in a solvent and a gelling agent is dispersed. Manufacturing method.
[7] The method for producing an electrochemical device according to any one of [1] to [6], wherein the removing step includes a step of heating the solution or the dispersion.
[8] The electrochemical step according to any one of [1] to [7], wherein the removing step includes a step of changing a pressure in the electrochemical device structure into which the solution or dispersion is injected. Device manufacturing method.
[9] The method for producing an electrochemical device according to any one of [1] to [8], wherein the solution or dispersion that has undergone the removing step is in a gel form.
[10] The method for producing a lithium ion secondary battery according to any one of [1] to [9], wherein the gelling agent is a low molecular weight type gelling agent.

  ADVANTAGE OF THE INVENTION According to this invention, in the electrochemical device represented by the lithium ion secondary battery using a gel electrolyte, the manufacturing method of the electrochemical device which does not reduce device performance and is simple can be provided.

Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail. In the present specification, “(meth) acryl” means “acryl” and “methacryl” corresponding thereto.
The electrochemical device manufacturing method of the present embodiment uses an electrolytic solution containing a phase transition type gelling agent as an electrolytic solution included in the electrochemical device, and uses the solution or dispersion containing the electrolytic solution as an electrochemical device structure. After the injection, the method includes a step of removing at least a part of the solvent contained in the solution or dispersion. In the present specification, the “electrolyte” is not only a liquid electrolyte in which each component contained therein is dissolved in a solvent, but also an electrolyte in a state where a solid including a slurry is dispersed, and a gel electrolyte Are also included.

<Electrolyte>
The electrolytic solution according to this embodiment contains (I) a solvent, (II) an electrolyte, and (III) a gelling agent.
As the solvent contained in the electrolytic solution, a non-aqueous solvent is preferable.
The non-aqueous solvent is not particularly limited and various solvents can be used, but a non-aqueous solvent that is liquid at room temperature is generally used.
Examples of such non-aqueous solvents include alcohols such as methanol, ethanol, isopropanol, butanol and octanol, methyl acetate, ethyl acetate, propyl acetate, butyl acetate and γ-butyrolactone, γ-valerolactone, ε-caprolactone, etc. Acid esters, ketones such as acetone, diethyl ketone, methyl ethyl ketone and 3-pentanone, hydrocarbons such as pentane, hexane, octane, cyclohexane, benzene, toluene, xylene, fluorobenzene and hexafluorobenzene, diethyl ether, dimethoxy Methane, 1,2-dimethoxyethane, 1,4-dioxane, crown ethers, glymes, ethers such as tetrahydrofuran and fluoroalkyl ether, N, N-dimethylacetate Amides, amides such as N, N-dimethylformamide and N-methylpyrrolidone (NMP), amines such as ethylenediamine and pyridine, imidazoles, propylene carbonate, ethylene carbonate, vinylene carbonate, fluoroethylene carbonate, dimethyl carbonate, diethyl carbonate Carbonates such as ethyl methyl carbonate, nitriles such as acetonitrile, propionitrile, adiponitrile, methoxyacetonitrile, sulfones such as sulfolane, sulfoxides such as dimethyl sulfoxide, industrial oils such as silicon oil and petroleum, edible oil, etc. Is mentioned.

Moreover, an ionic liquid can also be used as a non-aqueous solvent. An ionic liquid is a room temperature molten salt composed of ions obtained by combining an organic cation and an anion. Ionic liquids are flame retardant, have low explosive properties, have almost no vapor pressure, have high heat and ion conductivity, and can be designed to control physical properties by selecting ionic species. It is a feature.
Examples of the organic cation include imidazolium ions such as a dialkylimidazolium cation and a trialkylimidazolium cation, a tetraalkylammonium ion, an alkylpyridinium ion, a dialkylpyrrolidinium ion, and a dialkylpiperidinium ion.
Examples of the anion serving as a counter for these organic cations include PF ₆ anion, PF ₃ (C ₂ F ₅ ) ₃ anion, PF ₃ (CF ₃ ) ₃ anion, BF ₄ anion, and BF ₂ (CF ₃ ) ₂ anion. BF ₃ (CF ₃ ) anion, bisoxalatoborate anion, Tf (trifluoromethanesulfonyl) anion, Nf (nonafluorobutanesulfonyl) anion, bis (fluorosulfonyl) imide anion, bis (trifluoromethanesulfonyl) imide anion, bis (Pentafluoroethanesulfonyl) imide anion, dicyanoamine anion, halide anion.

  These non-aqueous solvents are used alone or in combination of two or more.

  When the electrochemical device is a lithium ion secondary battery or a lithium ion capacitor, examples of the non-aqueous solvent include an aprotic solvent. As the non-aqueous solvent contained in the electrolyte solution of the lithium ion secondary battery, an aprotic polar solvent is preferable. Specific examples thereof include ethylene carbonate, propylene carbonate, 1,2-butylene carbonate, trans-2,3-butylene carbonate, cis-2,3-butylene carbonate, 1,2-pentylene carbonate, and trans-2,3. -Cyclic carbonates represented by pentylene carbonate, cis-2,3-pentylene carbonate, trifluoromethylethylene carbonate, fluoroethylene carbonate and 4,5-difluoroethylene carbonate, vinylene carbonate and vinylethylene carbonate; γ-butyrolactone and Lactone represented by γ-valerolactone; cyclic sulfone represented by sulfolane; cyclic ether represented by tetrahydrofuran and dioxane; methyl ethyl carbonate, dimethyl carbonate -Bonate, diethyl carbonate, methyl propyl carbonate, methyl isopropyl carbonate, dipropyl carbonate, methyl butyl carbonate, dibutyl carbonate, ethyl propyl carbonate and methyl trifluoroethyl carbonate, and hydrogen atoms of dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate. Chain carbonates represented by fluorine-containing carbonates having one or more substituted with fluorine atoms; nitriles represented by acetonitrile, propionitrile and adiponitrile; dimethyl ether, 1,2-dimethoxyethane, 1,2-diethoxyethane, Diglyme, triglyme, 2,2,3,3,3-pentafluoropropyl methyl ether, 2,2,3,3,3-pentafur Ropropyl-1,1,2,2-tetrafluoroethyl ether, 1,1,2,2-tetrafluoroethyl methyl ether, 1,1,2,2-tetrafluoroethyl ethyl ether, 1,1,2,2 -Represented by tetrafluoroethyl-2,2,2-trifluoropropyl ether, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, and hexafluoroisopropyl methyl ether A chain ether such as ethyl acetate, butyl acetate, methyl propionate and ethyl propionate; and sulfur-containing compounds such as sulfolane, dimethyl sulfoxide and ethylene sulfite. These are used singly or in combination of two or more.

  When the electrolytic solution is used in a lithium ion secondary battery or a lithium ion capacitor, in order to increase the ionization degree of the lithium salt that is an electrolyte that contributes to the charge / discharge, the nonaqueous solvent is a cyclic aprotic polar solvent. It is preferable to include one or more types. From the same viewpoint, the non-aqueous solvent more preferably contains one or more cyclic carbonates typified by ethylene carbonate and propylene carbonate. The cyclic compound has a high dielectric constant, helps ionization of the lithium salt, and enhances the gelation ability.

<Solution or dispersion containing electrolyte solution>
The solution or dispersion containing the electrolytic solution according to the present embodiment (hereinafter simply referred to as “electrolyte-containing solution”) is removed because at least a part of the solvent is removed after it is injected into the electrochemical device structure. It is prepared so as to previously contain a solvent for the amount to be processed.
The solvent to be removed after the injection is preferably a solvent having a structure having a polar group from the viewpoint that there is little influence on the characteristics of the electrolytic solution even if there is a small amount of the residue that is not removed. In the present specification, the polar group means a functional group other than an unsubstituted hydrocarbon group, and examples thereof include a carbonate group, a keto group, an ester group, an ether group, a sulfoxide group, an amide group, a nitrile group, and a halogen group. .
From the viewpoint of ease of removal, the solvent removed after the injection preferably has the same or lower boiling point as the solvent remaining in the electrolytic solution after the removing step, and has a boiling point of 200 ° C. or lower. It is more preferable to include a solvent, it is further preferable to include a solvent having a boiling point of 150 ° C. or lower, and it is particularly preferable to include a solvent having a boiling point of 120 ° C. or lower. On the other hand, the solvent to be removed preferably contains a solvent having a boiling point of 40 ° C. or more, more preferably contains a solvent having a boiling point of 50 ° C. or more, and 60 ° C. or more from the viewpoint of excellent handling properties in a normal environment. It is more preferable to include a solvent having a boiling point of Examples of such solvents include dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate, and chains such as fluorine-containing carbonate in which one or more hydrogen atoms of dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate are substituted with fluorine atoms. Cyclic carbonates such as vinyl carbonate; cyclic ethers such as tetrahydrofuran and substituted or unsubstituted tetrahydrofuran typified by tetrahydrofuran and 2-methyltetrahydrofuran; 1,2-dimethoxyethane, 1,2-diethoxyethane and diglyme, 2, 2,3,3,3-pentafluoropropyl methyl ether, 2,2,3,3,3-pentafluoropropyl-1,1,2,2-tetrafluoroethyl ether, 1,1,2,2-te Lafluoroethyl methyl ether, 1,1,2,2-tetrafluoroethyl ethyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoropropyl ether, 1,1,2,2 -Chain ethers such as tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether and hexafluoroisopropyl methyl ether; esters such as acetate represented by ethyl acetate and butyl acetate; acetone and 3-pentanone Ketones; nitriles such as acetonitrile, propionitrile and adiponitrile; halogen-containing solvents such as chloroform and methylene chloride; and aromatic compounds such as toluene, xylene, thiophene, fluorobenzene and hexafluorobenzene. Among these, a chain carbonate and a nitrile are preferable from the viewpoint that the allowable amount of the residue that cannot be removed can be set more than other solvents and the removal operation can be simplified.

  The solvent removed after the injection may be one kind or two or more kinds. When a part of the solvent is removed, the solvent to be removed and the solvent remaining in the solution or dispersion after the removal may be the same as or different from each other. If the solvent to be removed and the remaining solvent are the same, it can be prepared with a small number of solvent types, so that the preparation of the solution or dispersion becomes easy. On the other hand, if the solvent to be removed and the remaining solvent are different from each other, the removal process can be easily managed due to the difference in physical properties between the two.

  The amount of the solvent previously contained in the electrolytic solution-containing solution and removed after the injection is preferably 1/10 to 20 times the amount of the electrolytic solution after the solvent is removed. When it is 1/10 or more times the amount of the electrolytic solution, it becomes easy to handle when preparing the electrolytic solution-containing solution, and when it is 20 or less, the removal step can be simplified.

  In addition, the electrolytic solution can be prepared by injecting the solvent into the solution after removing all or part of the solvent contained in the electrolytic solution-containing solution. The solvent to be injected again may be the same as or different from the removed solvent, and may be the same as or different from the remaining solvent.

(II) The electrolyte is not particularly limited as long as it is used as a normal nonaqueous electrolyte in the electrolytic solution, and any electrolyte may be used. When the electrolytic solution is used in a lithium ion secondary battery and a lithium ion capacitor, a lithium salt is used as an electrolyte. Specific examples of the lithium salt include, for example, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , Li ₂ SiF ₆ , LiOSO ₂ C _k F _{2k + 1} [k is an integer of 1 to 8], LiN (SO ₂ C _k F _{2k + 1} ) ₂ [k is an integer of 1-8], LiPF _n (C _k F _{2k + 1} ) _6-n [n is an integer of 1-5, k is an integer of 1-8], LiBF _n (C _k F _{2k + 1} ) _4-n [n is an integer of 1 to 3, k is an integer of 1 to 8], lithium bis (oxalate) borate represented by LiB (C ₂ O ₄ ) ₂ , LiBF ₂ (C ₂ O ₄₎ lithium difluoro represented by (oxalato) include _{borate, LiPF 3 (C 2 O 4} ) lithium trifluoromethane (oxalate) represented by phosphate, is LiPO ₂ F ₂ and Li ₂ PO ₃ F It is done.

Moreover, the lithium salt represented by the following general formula (3a), (3b) or (3c) can also be used as an electrolyte.
LiC (SO ₂ R ¹¹ ) (SO ₂ R ¹² ) (SO ₂ R ¹³ ) (3a)
LiN (SO ₂ OR ¹⁴ ) (SO ₂ OR ¹⁵ ) (3b)
LiN (SO ₂ R ¹⁶ ) (SO ₂ OR ¹⁷ ) (3c)
Here, in the formula, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ may be the same or different from each other, and are a C 1-8 perfluoroalkyl group. Indicates.

These electrolytes are used singly or in combination of two or more. In lithium ion secondary battery applications, among these electrolytes, LiPF ₆ , LiBF _4, and LiN (SO ₂ C _k F _{2k + 1} ) ₂ [k] from the viewpoint of improving gelation ability in addition to battery characteristics and stability. Is preferably an integer of 1 to 8.

  The concentration of the electrolyte is arbitrary and is not particularly limited as long as the object of the present invention is not hindered. The electrolyte is preferably 0.1 to 3 mol / mol in the electrolytic solution after removing at least a part of the solvent. It is contained at a concentration of 1 liter, more preferably 0.5 to 2 mol / liter. Further, in the electrolyte solution-containing solution before removing at least a part of the solvent, it is preferably prepared at a concentration of 0.005 to 2.8 mol / liter, more preferably 0.025 to 1.8 mol / liter. The

(III) The gelling agent is a phase transition type gelling agent. Here, the phase transition type gelling agent is a gelling agent capable of forming a gel capable of sol-gel transition by reversible physical interaction. Examples of the physical interaction include heat (temperature change), light irradiation, and pressure application. Therefore, the phase transition type gelling agent may be, for example, a compound that gels a solvent at room temperature and forms a sol when heated.
Such a gelling agent may be a polymer gelling agent or a non-polymeric low molecular weight gelling agent. Examples of the high molecular weight type gelling agent include polyvinylidene difluoride (PVdF) and a copolymer containing PVdF (for example, a copolymer of PVdF and hexafluoropropylene), polyacrylonitrile (PAN), Examples thereof include a copolymer having a PAN moiety (for example, a copolymer of acrylonitrile and (meth) acrylic ester) and a polymer having a polyether moiety. As the low molecular weight type gelling agent, for example, a compound having one or more groups of an amide group, a urea group and a urethane group, an amino acid derivative, “Chem. Rev. 97, p3133-p3159, published in 1997” , Compounds described in JP-A-10-175901, compounds described in International Publication No. 2006/82768, compounds described in JP-A-2007-506833, The compounds described in Kai 2009-155552, the compounds described in “Chem. Mater. 11, p649-655, 1999”, and “J. Phys. Chem. B 105, p12809- 12815, issued in 2001 ".

  The gelling agent that forms the phase transition type gel according to the present embodiment is a compound that forms an electrolyte solution containing the gel at 25 ° C. and becomes a sol when heated. This gelling agent is preferably a compound having a phase transition temperature between the gel and the sol of 40 ° C. or more and 200 ° C. or less. When the phase transition temperature is within this range, the handling properties of the electrolyte and the characteristics of electrochemical devices such as batteries can be achieved at a higher level. The phase transition temperature is measured by, for example, measuring storage elastic modulus and loss elastic modulus at each temperature of an electrolytic solution containing a gelling agent or an electrolytic solution-containing solution using a viscoelasticity measuring device, and curves of these values with respect to the temperature. Can be obtained as the temperature at which the curves intersect. Alternatively, the phase transition temperature is determined as the temperature at which the occurrence or disappearance of the peak derived from the gel structure formation is observed by measuring the temperature change of the X-ray scattering intensity for the electrolyte solution containing the gelling agent or the electrolyte-containing solution. Alternatively, the temperature can be obtained by irradiating the electrolyte solution containing the gelling agent or the electrolyte solution-containing solution with a laser beam while changing the temperature and changing the scattered light behavior. When measuring the phase transition temperature from changes in X-ray scattering intensity or laser scattered light intensity, the correlation between the phase transition temperature based on the viscoelastic behavior and their intensity is evaluated in advance, and the phase based on the viscoelastic behavior is evaluated. Convert to transition temperature.

  The phase transition type gelling agent may be a mixture of a plurality of gelling agents in order to develop the desired performance.

  As the phase transition type gelling agent, a low molecular weight type gelling agent is preferably used. The low molecular weight type gelling agent can gel the electrolytic solution with a smaller addition amount, and can lower the viscosity of the electrolytic solution at high temperatures. Among them, compounds having chemical stability and oxidation-reduction stability are preferably used, and examples of such compounds include the compounds described below.

The low molecular weight type gelling agent according to the present embodiment is represented by the following general formulas (1), (2), and (3) from the viewpoint of electrochemical stability and gelling ability with respect to the electrolytic solution. More preferably, it includes one or more compounds selected from the group consisting of compounds.
^{Rf 1 -R 1 -X 1 -L 1} -R 2 (1)
Rf ¹ -R ¹ -X ¹ -L ¹ -R ³ -L ² -X ² -R ⁴ -Rf ² (2)
^{R 5 -O-Cy-X 3} -Cm (3)

In the general formulas (1) and (2), Rf ¹ and Rf ² each independently represents a C 2-20 perfluoroalkyl group. When the number of carbon atoms is 2 to 20, it is easy to obtain raw materials and synthesize the compounds. From the viewpoints of the compatibility of the compounds represented by the above general formulas (1) and (2) (hereinafter also referred to as “perfluoro compounds”) into the electrolytic solution, the electrochemical characteristics of the electrolytic solution, and the gelling ability. The carbon number is preferably 2-12. Examples of the perfluoroalkyl group include perfluoroethyl group, perfluoro n-propyl group, perfluoroisopropyl group, perfluoro n-butyl group, perfluoro t-butyl group, perfluoro n-hexyl group, perfluoro n. -An octyl group, a perfluoro n-decyl group, and a perfluoro n-dodecyl group are mentioned.

In the general formulas (1) and (2), R ¹ and R ⁴ each independently represent a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms, and the carbon number is 2 to 5. And preferred. When the divalent saturated hydrocarbon group has 3 or more carbon atoms, it may or may not be branched. Examples of such a divalent saturated hydrocarbon group include a methylidene group, an ethylene group, an n-propylene group, an isopropylene group, and an n-butene group.

X ¹ and X ² are each independently selected from the group consisting of groups represented by the following formulas (1a), (1b), (1c), (1d), (1e), (1f) and (1g). The divalent group selected is shown. Among these, from an electrochemical standpoint, a divalent group selected from the group consisting of groups represented by the following formulas (1a), (1b) and (1d) is preferable, and the following formula (1a) or the following formula: The divalent group represented by (1d) is more preferable, and the divalent group represented by the following formula (1d) is more preferable.

L ¹ and L ² may each independently be substituted with a single bond, an alkyl group or a halogen atom (that is, may be unsubstituted) an oxyalkylene group, an alkyl group or a halogen atom. A good (ie, unsubstituted) oxycycloalkylene group, or a divalent oxyaromatic group (—OAr) optionally substituted (ie, optionally substituted) with an alkyl group or a halogen atom -; Ar represents a divalent aromatic group. Examples of the oxyalkylene group include an oxyalkylene group having 2 to 10 carbon atoms, more specifically, an oxyethylene group (—C ₂ H ₄ O—) and an oxypropylene group (—C ₃ H ₆ O—). Can be mentioned. Examples of the oxycycloalkylene group include an oxycycloalkylene group having 5 to 12 carbon atoms, and more specifically, an oxycyclopentylene group, an oxycyclohexylene group, and an oxydicyclohexylene group.

  Among these, a divalent oxyaromatic group is preferable from the viewpoint of gelling ability and improving the safety of the electrolytic solution. The divalent aromatic group in the divalent oxyaromatic group which may be substituted with an alkyl group or a halogen atom is a cyclic divalent group exhibiting so-called “aromaticity”. The divalent aromatic group may be a carbocyclic group or a heterocyclic group. The carbocyclic group has 6 to 30 nuclear atoms, and may be substituted with an alkyl group or a halogen atom as described above, or may not be substituted. Specific examples thereof include a divalent group having a nucleus represented by a phenylene group, a biphenylene group, a terphenylene group, a naphthylene group, an anthranylene group, a phenanthrylene group, a pyrenylene group, a chrysenylene group, and a fluoranthenylene group. It is done.

The heterocyclic group has 5 to 30 nuclear atoms, and includes, for example, a nucleus represented by a pyrrolene group, a furylene group, a thiophenylene group, a triazolen group, an oxadiazolene group, a pyridylene group, and a pyrimidylene group. And a divalent group. Among these, as the divalent aromatic group, a phenylene group, a biphenylene group, or a naphthylene group is preferable. Examples of the alkyl group that is a substituent include a methyl group and an ethyl group, and examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.
The oxycycloalkylene group and the oxyaromatic group include those in which a plurality of rings are connected, and examples of such a group include an oxybiphenylene group, an oxyterphenylene group, and an oxycycloalkylphenylene group.

R ² in the general formula (1) is an alkyl group having 1 to 20 carbon atoms, an alkyl group, or a halogen atom (provided that it may be substituted with an alkyl group or a halogen atom (excluding a fluorine atom)). A fluoroalkyl group, an aryl group or a fluoroaryl group optionally substituted with a fluorine atom, or one or more of these groups and a divalent group corresponding to these groups (for example, alkyl A monovalent group (for example, an aralkyl group in which an alkylene group and an aryl group are bonded) bonded to one or more of an alkylene group corresponding to a group and an arylene group corresponding to an aryl group. More specifically, as R ² , methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and n-decyl group And an alkyl group having 1 to 12 carbon atoms represented by This alkyl group may or may not be further substituted with an alkyl group or a halogen atom (excluding a fluorine atom).

  As a fluoroalkyl group, a C1-C12 fluoroalkyl group (however, except a perfluoroalkyl group) or a C1-C12 perfluoroalkyl group is preferable. Specific examples of the fluoroalkyl group having 1 to 12 carbon atoms (excluding the perfluoroalkyl group) and the perfluoroalkyl group having 1 to 12 carbon atoms include a trifluoromethyl group, 1,1,1,2 , 2-pentafluoroethyl group, 1,1,2,2-tetrafluoroethyl group, 1,1,1,2,2,3,3-heptafluoron-butyl group, 1,1,2,2, 3,3,4,4,5,5,6,6-dodecafluoro n-hexyl group and 1,1,1,2,2,3,3,4,4,5,5,6,6-tri A decafluoro n-decyl group is mentioned. The fluoroalkyl group may be further substituted with an alkyl group or a halogen atom (excluding a fluorine atom), or may not be substituted.

As an aryl group, for example, an aryl group having 6 to 12 nuclear atoms represented by a phenyl group, a biphenyl group, and a naphthyl group, and a fluoroaryl group, for example, a monofluorophenyl group, a difluorophenyl group, a tetrafluorophenyl Examples thereof include a fluoroaryl group having 6 to 12 nuclear atoms represented by the group.
R ² represents one or more of the aforementioned alkyl group, fluoroalkyl group, aryl group and fluoroaryl group, and a divalent group corresponding to these groups, that is, an alkylene group, a fluoroalkylene group, an arylene group. A monovalent group in which one or more of a group and a fluoroarylene group are bonded may be used. Examples of such a group include a group in which an alkylene group and a perfluoroalkyl group are bonded (however, this group is also a kind of fluoroalkyl group), a group in which an alkylene group and an aryl group are bonded (aralkyl). Group), a group in which a fluoroalkyl group and a fluoroarylene group are bonded to each other.

R ² is preferably an alkyl group or a fluoroalkyl group from the viewpoint of more effectively and reliably achieving the effects of the present embodiment, and is an alkyl group having 1 to 12 carbon atoms or a fluoroalkyl group having 1 to 12 carbon atoms (provided that Or a perfluoroalkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms or a fluoroalkyl group having 2 to 10 carbon atoms (provided that the perfluoroalkyl group is a perfluoroalkyl group). It is more preferable that the group is excluded.

R ³ in the general formula (2) may or may not have one or more oxygen and / or sulfur atoms in the main chain, and may or may not be substituted with an alkyl group. A divalent saturated hydrocarbon group having 1 to 18 carbon atoms is shown. The said carbon number is preferable in it being 1-16, and more preferable in it being 2-14. The gelling ability can also be controlled by the number of carbon atoms in R ³ . Moreover, the carbon number of the said range is preferable from a viewpoint of a synthesis | combination and raw material acquisition.

Examples of the gelling agent having a perfluoroalkyl group represented by the general formula (1) or (2) include Rf ¹ -R ¹ —O—R ² and Rf ¹ —R ¹ —S—R ^2. Rf ¹ -R ¹ -SO ₂ -R ² , Rf ¹ -R ¹ -OCO-R ² , Rf ¹ -R ¹ -O-Ar-O-R ² (where Ar is a divalent aromatic group) are shown. ^{Similarly.), Rf 1 -R 1 -SO} 2 -Ar-O-R 2, Rf 1 -R 1 -SO 2 -Ar-O-Rf 4, Rf 1 -R 1 -SO 2 -Ar —O—Rf ³ —Rf ⁴ (where Rf ³ represents a fluoroalkylene group and Rf ⁴ represents a fluoroalkyl group), Rf ¹ —R ¹ —SO—Ar—O—R ² , Rf ¹ —R ¹ —S—Ar—O—R ² , Rf ¹ —R ¹ —O—R ⁵ —O—R ² (wherein R ⁵ represents an alkylene group), Rf ¹ —R ¹ —CONH—R ² , Rf ¹ -R ^1— SO ₂ —Ar ¹ —O—R ³ —O—Ar ² —SO ₂ —R ⁴ —Rf ² (wherein Ar ¹ and Ar ² each independently represent a divalent aromatic group. . ^{Similarly), Rf 1 -R 1 -O-} Ar 1 -O-R 3 -O-Ar 2 -O-R 4 -Rf 2, Rf 1 -R 1 -SO 2 -Ar 1 -O-R 6 - Examples include compounds represented by the general formula: O—R ⁷ —O—Ar ² —O—R ⁴ —Rf ² (wherein R ⁶ and R ⁷ each independently represents an alkylene group; the same shall apply hereinafter). It is done. More specifically, Rf ¹ and Rf ² are each independently a perfluoroalkyl group having 2 to 10 carbon atoms, R ¹ is an alkylene group having 2 to 4 carbon atoms, Ar is (or Ar ¹ and Ar ² are each Independently, a p-phenylene group or a p-biphenylene group, a compound represented by each of the above general formulas wherein R ² is an alkyl group having 4 to 8 carbon atoms, and a dimer structure thereof, for example, Rf ¹ -R ^1- O—Ar—O—R ² , Rf ¹ —R ¹ —SO ₂ —Ar—O—R ² , Rf ¹ —R ¹ —O—Ar ¹ —O—R ³ —O—Ar ² —O— R ⁴ —Rf ² , Rf ¹ —R ¹ —SO ₂ —Ar ¹ —O—R ⁶ —O—R ⁷ —O—Ar ² —O—R ⁴ —Rf ² are exemplified. It is done.

  In the general formula (3), Cy represents a substituted or unsubstituted divalent aromatic hydrocarbon group or alicyclic hydrocarbon group having 5 to 30 nuclear atoms. The divalent aromatic hydrocarbon group is a cyclic divalent group exhibiting so-called “aromaticity”. This divalent aromatic hydrocarbon group may be a carbocyclic group or a heterocyclic group. These divalent aromatic hydrocarbon groups may be substituted with a substituent or may be an unsubstituted one that is not substituted. A substituent of the divalent aromatic hydrocarbon group can be selected from the viewpoint of synthesis or availability of raw materials. Alternatively, the substituent of the divalent aromatic hydrocarbon group can be selected from the viewpoint of the melting temperature and gelling ability of the gelling agent.

The carbocyclic group has 6 to 30 nuclear atoms, may be substituted with a substituent, or may be unsubstituted or unsubstituted. Specific examples thereof include divalent groups having a nucleus represented by a phenylene group, a biphenylene group, a terphenylene group, a naphthylene group, an anthranylene group, a phenanthrylene group, a pyrenylene group, a chrysenylene group, and a fluoranthenylene group. It is done.
The heterocyclic group has 5 to 30 nuclear atoms, and includes, for example, a nucleus represented by a pyrrolene group, a furylene group, a thiophenylene group, a triazolen group, an oxadiazolene group, a pyridylene group, and a pyrimidylene group. And a divalent group.
The aromatic hydrocarbon group is a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 20 nuclear atoms from the viewpoints of availability of raw materials and ease of synthesis and gelation ability in the electrolytic solution. And more preferably a group selected from the group consisting of a phenylene group, a biphenylene group, a naphthylene group, a terphenylene group and an anthranylene group.
Moreover, as said substituent, the alkyl group represented by the methyl group and the ethyl group, and a halogen atom are mentioned.

  The alicyclic hydrocarbon group has 5 to 30 nuclear atoms, and examples thereof include a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.

  An aromatic hydrocarbon group or an alicyclic hydrocarbon group has a plurality of groups connected if the number of nuclear atoms is within the range, or has both a carbocyclic ring and a heterocyclic ring. You may have both with an alicyclic group.

In the general formula (3), R ⁵ represents a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms in the main chain, and may be saturated or unsaturated. R ⁵ may be an aliphatic hydrocarbon group and may further have an aromatic hydrocarbon group. A part or all of the hydrocarbon groups in the aliphatic hydrocarbon group and aromatic hydrocarbon group may be substituted with a halogen atom. When the monovalent hydrocarbon group is a monovalent aliphatic hydrocarbon group, it may be branched or unbranched, and a part or all of the branched chain may be substituted with a halogen atom. . Moreover, this hydrocarbon group may have an oxygen atom and / or a sulfur atom in its chain. Furthermore, when the monovalent hydrocarbon group has an aromatic hydrocarbon group, this aromatic hydrocarbon group may or may not further have a substituent. However, the monovalent hydrocarbon group is obtained by dissolving the compound represented by the general formula (3) (hereinafter also referred to as “compound (3)”) in a solvent, Therefore, a hydrocarbon group that makes the compound (3) easily soluble in a solvent, such as an aralkyl group typified by a benzyl group, is preferable. Moreover, when the carbon number of the monovalent hydrocarbon group is 21 or more, it tends to be difficult to obtain raw materials. The monovalent hydrocarbon group represented by R ⁵ is preferably an alkyl group having 4 to 18 carbon atoms, and an alkyl group having 4 to 14 carbon atoms from the viewpoint of more effectively and reliably achieving the above effects in the present embodiment. Is more preferable. R ⁵ is preferably a linear alkyl group from the viewpoint of gelling ability and handling properties.

上記一般式（３）において、Ｘ³は化合物（３）をリチウムイオン二次電池に用いた際に、長期にわたって安定である点とゲル化能とから選択すると好ましい。Ｘ³が上記式（３ａ）で表される基である場合、そのゲル化剤を含む組成物は、非常に安定性が高いゲルとなる傾向にある。また、Ｘ³が上記式（３ｅ）で表される基である場合、そのゲル化剤を含む組成物は、ゲル−ゾルの転移を温度調整だけではなく、光照射によっても誘起できる点で用途拡大に繋がる。 In the general formula (3), X ³ represents the following formulas (3a), (3b), (3c), (3d), (3e), (3f) and (3g) (hereinafter, (3a) to (3g) Or a divalent group in which two or more of the groups represented by the following formulas (3a) to (3g) are bonded to each other. Show. Among these, a divalent group of any one of the groups represented by the following formulas (3a), (3e) and (3g) is preferable.

In the above general formula (3), X ³ is preferably selected from the point of being stable over a long period of time and the gelling ability when the compound (3) is used in a lithium ion secondary battery. When X ³ is a group represented by the above formula (3a), the composition containing the gelling agent tends to be a very stable gel. When X ³ is a group represented by the above formula (3e), the composition containing the gelling agent can be used in that the gel-sol transition can be induced not only by temperature adjustment but also by light irradiation. It leads to expansion.

In the general formula (3), Cm represents a monovalent group (coumarin moiety) represented by the following general formula (3z). In the following formula (3z), a plurality of R ^a are each independently a hydrogen atom. Represents an alkyl group, an alkoxy group or a halogen atom. When R ^a is an alkyl group, the carbon number is preferably 1 to 6, and when it is an alkoxy group, the carbon number is preferably 1 to 8.

  A low molecular weight type gelling agent is used individually by 1 type or in combination of 2 or more types.

  The low molecular weight type gelling agent according to this embodiment may be synthesized by a conventional method, or a commercially available product may be obtained. Among these gelling agents, those having a perfluoroalkyl group include, for example, International Publication No. 2007/083843, Japanese Patent Application Laid-Open No. 2007-191626, Japanese Patent Application Laid-Open No. 2007-191627, and Japanese Patent Application Laid-Open No. 2007-191661. It can manufacture with reference to the method of gazette and international publication 2009/78268.

The gelling agent having a perfluoroalkyl group used in the present embodiment can be synthesized by the following scheme, for example. First, a thiol compound represented by the following general formula (11a) is sulfided with a compound represented by the following general formula (11b) in the presence of a base such as triethylamine in a solvent such as dry THF. The compound represented by (11c) is obtained.
HS-Ar-OH (11a)
C _m F _{2m + 1} C _p H _2p X ¹ (11b)
_{C m F 2m + 1 C p} H 2p -S-Ar-OH (11c)

Next, the compound represented by the general formula (11c) is etherified with a compound represented by the following general formula (11d) in the presence of an alkali metal compound such as K ₂ CO _{3 in} a solvent such as 3-pentanone. To obtain a compound represented by the following general formula (11e).
R ¹ X ² (11d)
_{C m F 2m + 1 C p} H 2p -S-Ar-O-R 1 (11e)

Then, the perfluoro compound represented by the following general formula (11j) is obtained by oxidizing the compound represented by the general formula (11e) with an oxidizing agent such as hydrogen peroxide in the presence of a catalyst such as acetic acid. Is obtained.
_{C m F 2m + 1 C p} H 2p -SO 2 -Ar-O-R 1 (11j)
Here, as long as in the production scheme of the perfluoro compound represented by the general formula (11j), Ar represents a substituted or unsubstituted divalent aromatic group having 8 to 30 nuclear atoms, and R ¹ is saturated or Represents an unsaturated monovalent hydrocarbon group having 1 to 20 carbon atoms, m represents a natural number of 2 to 16, p represents an integer of 0 to 6, and X ¹ represents a halogen atom such as an iodine atom, for example. X ² represents a halogen atom such as a bromine atom.

  As such a synthesis method, for example, the synthesis method described in International Publication No. 2009/78268 can be referred to.

Further, when Ar is a group in which a plurality of aromatic rings such as a biphenylene group or a terphenylene group are bonded by a single bond, a perfluoro compound represented by the above general formula (11j) is obtained by the following synthesis method, for example. Can do. First, a thiol compound represented by the following general formula (11f) is sulfided with a compound represented by the above general formula (11b) in the presence of a base such as triethylamine in a solvent such as dry THF. A compound represented by (11 g) is obtained. Here, in the formulas (11f) and (11g), m and p are as defined in the formula (11j), X ³ represents a halogen atom such as a bromine atom, and Ar ² represents the above formula (11j). ) Represents a part of the divalent aromatic hydrocarbon group constituting Ar.
^{HS-Ar 2 -X 3 (11f} )
_{C m F 2m + 1 C p} H 2p -S-Ar 2 -X 3 (11g)

Next, the following compound (11h) is obtained by oxidizing the compound represented by the general formula (11g) with an oxidizing agent such as hydrogen peroxide in the presence of a catalyst such as acetic acid. Here, in the formula (11h), Ar ² , X ³ , m and p are as defined in the formula (11g).
_{C m F 2m + 1 C p} H 2p -SO 2 -Ar 2 -X 3 (11h)

Then, from the compound represented by the above general formula (11h) and the compound represented by the following general formula (11i), in the presence of a palladium catalyst in a basic aqueous solution such as K ₂ CO ₃ , Suzuki-Miyaura coupling To obtain the perfluoro compound represented by the general formula (11j). Here, in the formula (11i), R ¹ has the same meaning as in the formula (11j), Ar ³ is Ar ² a divalent aromatic hydrocarbon group constituting Ar in the formula (11j) A part different from is shown, and Ar ² and Ar ³ bonded by a single bond is Ar.
R ¹ —O—Ar ³ —B (OH) ₂ (11i)

Moreover, the gelling agent which has the perfluoroalkyl group used for this embodiment is compoundable with the following scheme, for example. That is, from the compound represented by the following general formula (Ia) and the compound represented by the following general formula (IIa), dehydration condensation such as Mitsunobu reaction is a kind of gelling agent having a perfluoroalkyl group. A compound represented by the general formula (IIIa) can be synthesized. Here, in the formula, Y ¹ and Y ² are each independently a sulfur atom or an oxygen atom.
^{Rf 1 -R 1 -Y 1 -Z-} Y 2 H (Ia)
Rf ² R ² OH (IIa)
^{Rf 1 -R 1 -Y 1 -Z-} Y 2 -R 2 -Rf 2 (IIIa)

Further, in the compound represented by the above general formula (IIIa), when Y ¹ and / or Y ² is a sulfur atom, the sulfur atom is further sulfonylated or sulfoxidized to have a perfluoroalkyl group. A compound represented by the following general formula (IVa), which is another kind of gelling agent, can be synthesized. Here, at least one of Y ³ and Y ⁴ is an SO group or SO ₂ group, and when one of Y ³ and Y ⁴ is an SO group or SO ₂ group, the other is a sulfur atom or an oxygen atom.
^{Rf 1 -R 1 -Y 3 -Z-} Y 4 -R 2 -Rf 2 (IVa)

The compound represented by the general formula (Ia) is, for example, a perfluoroalkane halide (thiol group or a hydrogen atom of a hydroxyl group) of a compound represented by the following formula (Va) under alkaline conditions ( For example, it can be synthesized by substitution with a perfluoroalkyl group of iodide.
HY ¹ -ZY ² H (Va)

  The compound represented by the above formula (IIa) can be synthesized by further reducing the halide of alkanol obtained by the addition reaction of perfluoroalkane halide (for example, iodide) to alkenol.

Here, as long as in the production scheme of the perfluoro compound (gelator) represented by the above general formula (IIIa) or (IVa), Rf ¹ and Rf ² are each independently of 2 to 18 carbon atoms in the main chain. A substituted or unsubstituted perfluoroalkyl group, R ¹ and R ² each independently represents a single bond or a substituted or unsubstituted divalent hydrocarbon group having 1 to 8 carbon atoms in the main chain; A substituted or unsubstituted divalent aromatic hydrocarbon group or alicyclic hydrocarbon group having 5 to 30 nuclear atoms is shown.

  However, the synthesis method of the gelling agent having a perfluoroalkyl group used in the present embodiment is not limited to the above method.

  In addition, the compound (3) according to this embodiment is a coumarin-type gelling agent, and for example, the compound described in the liquid crystal discussion conference proceedings collection p44 (2007) can be used as the compound (3).

The compound (3) having an azo group, that is, the compound (3) in which X ³ is represented by the above formula (3e) can be synthesized, for example, by the following reaction pathway.

Examples of the compound (3) having an azo group synthesized in this way include a compound represented by the following formula (3I) (hereinafter also referred to as “compound (3I)”) and the following formula (3II). And a compound represented by the following (hereinafter also referred to as “compound (3II)”).

ナスフラスコに濃硝酸及び濃硫酸の混合溶液を加える。当該ナスフラスコを氷浴で冷却しながら、クマリンを、混合溶液の温度が２０℃を超えないように徐々に加える。クマリンを全量加え終えたら氷浴を外し、室温で１時間攪拌して反応させる。当該反応液を水中に注ぎ、析出した固体を濾取する。濾取した固体を、トルエンで再結晶を行い、淡黄色の固体の化合物（ａ）を得る。 Hereinafter, a method for synthesizing the compounds (3I) and (3II) will be described in detail.
[Method for Synthesizing Compound (3I)]
(Step 1: Synthesis of Compound (a))

Add a mixed solution of concentrated nitric acid and concentrated sulfuric acid to the eggplant flask. While cooling the eggplant flask in an ice bath, coumarin is gradually added so that the temperature of the mixed solution does not exceed 20 ° C. When all the coumarin has been added, remove the ice bath and stir at room temperature for 1 hour to react. The reaction solution is poured into water, and the precipitated solid is collected by filtration. The solid collected by filtration is recrystallized from toluene to obtain a light yellow solid compound (a).

ナスフラスコにおいて、化合物（ａ）をエタノール及びトルエンの混合溶液に溶かして、Ｐｄ／Ｃの存在下、水素添加反応を行う。水素添加反応後、Ｐｄ／Ｃを濾取し、濾液をエバポレーターで濃縮する。析出した固体をトルエンで再結晶を行い、黄色固体の化合物（ｂ）を得る。 (Step 2: Synthesis of Compound (b))

In an eggplant flask, the compound (a) is dissolved in a mixed solution of ethanol and toluene, and a hydrogenation reaction is performed in the presence of Pd / C. After the hydrogenation reaction, Pd / C is collected by filtration, and the filtrate is concentrated by an evaporator. The precipitated solid is recrystallized from toluene to obtain a yellow solid compound (b).

ナスフラスコにおいて、５℃の氷冷下、１２Ｎの塩酸水溶液を調製する。当該水溶液中に、化合物（ｂ）及び亜硝酸ナトリウム（ＮａＮＯ₂）を加えて、２０分間攪拌する。さらに、フェノール、水酸化ナトリウム及び水の混合溶液を加えて攪拌する。析出した固体をトルエンで再結晶を行い、化合物（ｃ）を得る。 (Step 3: Synthesis of Compound (c))

In an eggplant flask, a 12N aqueous hydrochloric acid solution is prepared under ice cooling at 5 ° C. Compound (b) and sodium nitrite (NaNO ₂ ) are added to the aqueous solution and stirred for 20 minutes. Further, a mixed solution of phenol, sodium hydroxide and water is added and stirred. The precipitated solid is recrystallized from toluene to obtain compound (c).

ナスフラスコにおいて、化合物（ｃ）を３−ペンタノンに溶解する。得られた溶液中に、１−ブロモオクタン及び炭酸カリウムを加えて１５時間還流を行う。得られた固体をトルエンで再結晶させ、カラムクロマトグラフィーで精製して化合物（３Ｉ）を得る。なお、上記カラムクロマトグラフィーにおいて、充填剤としてシリカゲルを用い、展開溶媒としてクロロホルムを用いる。 (Step 4: Synthesis of Compound (3I))

In an eggplant flask, compound (c) is dissolved in 3-pentanone. 1-Bromooctane and potassium carbonate are added to the obtained solution and refluxed for 15 hours. The obtained solid is recrystallized from toluene and purified by column chromatography to obtain compound (3I). In the column chromatography, silica gel is used as a filler and chloroform is used as a developing solvent.

ナスフラスコにおいて、化合物（ｃ）を３−ペンタノンに溶解する。得られた溶液中に、１−ブロモヘキサン及び炭酸カリウムを加えて１５時間還流を行う。得られた固体をトルエンで再結晶を行い、カラムクロマトグラフィーで精製して化合物（３ＩＩ）を得る。なお、上記カラムクロマトグラフィーにおいて、充填剤としてシリカゲルを用い、展開溶媒としてクロロホルムを用いる。 [Method for Synthesizing Compound (3II)]

In an eggplant flask, compound (c) is dissolved in 3-pentanone. 1-Bromohexane and potassium carbonate are added to the obtained solution and refluxed for 15 hours. The obtained solid is recrystallized from toluene and purified by column chromatography to obtain compound (3II). In the column chromatography, silica gel is used as a filler and chloroform is used as a developing solvent.

  However, the manufacturing method of a compound (3) is not limited to the said method.

  The content of the gelling agent according to the present embodiment in the phase transition type gel can gel the electrolyte after the step of removing at least a part of the solvent or the step added after that as necessary. There is no particular limitation as long as it is such an amount. However, from the viewpoint of improving handling characteristics, characteristics as an electrochemical device, and low cost in a well-balanced manner, the content thereof is based on 100 parts by mass of the total amount of the solvent and the electrolyte after removing at least a part of the solvent. , 0.01 to 20 parts by mass, and more preferably 0.1 to 10 parts by mass. Similarly, before removing at least a part of the solvent, the content of the gelling agent is preferably 0.0005 to 18 parts by mass with respect to 100 parts by mass of the total amount of the solvent and the electrolyte. It is more preferable in it being -8 mass parts.

The phase transition type gel according to this embodiment may further contain an additive as necessary. Examples of the additive include a heat stabilizer, a flame retardant, a thermal runaway inhibitor, an overcharge suppression additive, a thickener, an emulsifier, a reinforcing agent, and an additive for forming an electrode protective film. These additives may be solid (bulk) or powder, may be liquid, may be dissolved in the electrolytic solution, or may not be dissolved.
The addition amount of the additive is selected within a range that does not hinder the achievement of the object of the present invention and can achieve the purpose of use of the additive. In order to achieve compatibility with the effect of the additive, the content of the additive is 0.5 parts by mass to 20 parts by mass with respect to 100 parts by mass of the total amount of the solvent and the electrolyte after removing at least a part of the solvent. 1 part by mass to 10 parts by mass is more preferable. Similarly, before removing at least a part of the solvent, the additive is preferably added in an amount of 0.025 parts by mass to 18 parts by mass with respect to 100 parts by mass of the total amount of the solvent and the electrolyte.
When the phase transition type gel according to the present embodiment is used as an electrolyte of a lithium ion secondary battery, an electrode protective film is used in order to reduce gas generation during battery preparation and charge / discharge and to perform stable charge / discharge. As an additive for formation, it is effective to use a compound having an unsaturated bond (excluding an unsaturated bond of C═O) and / or a fluorine atom. Examples of the compound having an unsaturated bond (excluding an unsaturated bond of C═O) and / or a fluorine atom include, for example, a part of a carbonate compound often used in an electrolyte solution as an alkene, carbonate Examples include compounds in which some hydrogen atoms in a compound are substituted with fluorine atoms, compounds having a thiophene moiety, compounds having a furan moiety, compounds having a nitrile moiety, compounds having a sulfite moiety, and compounds having a sulfone moiety. More specifically, examples of the compound having an unsaturated bond (excluding an unsaturated bond of C═O) and / or a fluorine atom include, for example, vinylene carbonate, vinyl ethylene carbonate, diallyl carbonate, fluoroethylene carbonate, and Difluoroethylene carbonate is mentioned. The additive for forming the film is 0.1 mass with respect to 100 mass parts of the total amount of the solvent and the electrolyte after the step of removing at least a part of the solvent or the step of adding after that if necessary. Parts to 10 parts by mass, preferably 0.5 parts to 5 parts by mass. An additive is used individually by 1 type or in combination of 2 or more types, For example, the additive which assists electrode protective film formation can also be added further. Furthermore, when the phase transition type gel according to the present embodiment is used as an electrolyte of a lithium ion secondary battery, for example, an additive that can be added to a conventional electrolyte can be mixed with the electrolyte.

  The phase transition temperature from the gel to the sol of the phase transition type gel is between 40 ° C. and 200 ° C. in the electrolytic solution that has undergone the process of removing at least a part of the solvent, or the process added after that as necessary. Preferably, it is between 50 ° C and 150 ° C. When the phase transition temperature is in this range, the characteristics (safety, adhesiveness, freedom of form) of the gel electrolyte and the ease of producing an electrochemical device such as a battery can be more effectively achieved.

  The mixing ratio of the solvent, the electrolyte, and the gelling agent can be selected according to the purpose, but both the concentration of the electrolyte and the content of the gelling agent are within the above-mentioned preferable range at the stage where at least a part of the solvent is removed. Furthermore, it is desirable that it is in a more preferable range. By preparing the electrolytic solution with such a composition, it is possible to further improve the characteristics of electrochemical devices such as batteries, handling properties, and safety.

  The electrolyte-containing liquid to be injected into an electrochemical device structure such as a battery is a gel containing a solvent, an electrolyte, and a gelling agent, even if the electrolyte and the gelling agent are dissolved in a solvent. Alternatively, it may be a slurry in which an electrolyte is dissolved in a solvent and a gelling agent is dispersed. If the electrolytic solution-containing liquid is in a liquid state, it is preferable because it can be easily injected into the electrochemical device structure and impregnated into the electrochemical device structure. On the other hand, the gel form is preferable because the amount of the solvent to be removed is small and the removal process becomes simple. Furthermore, a slurry in which a gelling agent is dispersed is preferable because the injection of the electrolyte solution-containing liquid and the removal of the solvent are simplified. “Slurry” means a muddy state in which a solid (gelling agent) is dispersed in a liquid (electrolyte-containing liquid, electrolyte), that is, there is a solid that does not dissolve in the liquid. This refers to a fluid that is in a solid-liquid two-phase system (a state in which no solid is precipitated) and is in a muddy state due to the presence of a certain amount of solids.

The method for preparing the electrolytic solution-containing solution according to the present embodiment is not particularly limited as long as the components contained therein are mixed, and the order of mixing the components is not limited. For example, when the electrolytic solution-containing solution includes a solvent, an electrolyte, and a gelling agent, the order of mixing the electrolyte, the solvent, and the gelling agent is not limited. More specifically, after a predetermined amount of electrolyte and a solvent are mixed to prepare a preliminary electrolyte solution-containing solution, a gelling agent is mixed with the preliminary electrolyte solution-containing solution, and the electrolysis of this embodiment is performed. A liquid-containing liquid can be obtained. Alternatively, it is possible to obtain the electrolytic solution-containing liquid of the present embodiment by simultaneously mixing all the components in a predetermined amount. In addition, in the preparation method of electrolyte solution containing liquid, the mixture containing a gelatinizer can be once heated, and it can cool to room temperature in the state in which each component in a mixture became uniform.
The electrolytic solution-containing solution of the present embodiment is a raw material for the electrolytic solution, and as is apparent from the above, the electrolytic solution can be obtained by removing at least part of the solvent contained therein. The electrolytic solution is also an electrolyte containing a gelling agent that forms a phase transition type gel, and is preferably used in a lithium ion secondary battery.

  In the method for manufacturing an electrochemical device according to the present embodiment, an electrolytic solution or an electrolytic solution-containing liquid is prepared in the electrochemical device structure prepared in advance before the electrolytic solution-containing liquid is injected into the electrochemical device structure. You may have the process of containing a part of.

  For example, when the electrochemical device of the present embodiment is a lithium ion secondary battery or a lithium ion capacitor, the electrochemical device structure only needs to include an exterior of the electrochemical device, and the positive electrode, It may further include one or more members selected from the group consisting of a negative electrode and a separator, and may further include a part of the electrolytic solution or the electrolytic solution-containing solution. Hereinafter, although the case where an electrochemical device is a lithium ion secondary battery is demonstrated, an electrochemical device is not limited to this. A positive electrode, a negative electrode, and a separator are demonstrated below, for example.

<Positive electrode>
A positive electrode will not be specifically limited if it acts as a positive electrode of a lithium ion secondary battery, A well-known thing may be used. The positive electrode preferably contains one or more materials selected from the group consisting of materials capable of inserting and extracting lithium ions as the positive electrode active material. Examples of such materials include composite oxides represented by the following general formulas (6a) and (6b), metal chalcogenides and metal oxides having a tunnel structure and a layered structure, and olivine-type phosphate compounds.
Li _x MO ₂ (6a)
Li _y M ₂ O ₄ (6b)
Here, in the formula, M represents one or more metals selected from transition metals, x represents a number from 0 to 1, and y represents a number from 0 to 2.

More specifically, for example, lithium cobalt oxide typified by LiCoO ₂ ; lithium manganese oxide typified by LiMnO ₂ , LiMn ₂ O ₄ , Li ₂ Mn ₂ O ₄ ; lithium nickel typified by LiNiO ₂ Oxide; represented by Li _z MO ₂ (M represents two or more elements selected from the group consisting of Ni, Mn, Co, Al, and Mg, and z represents a number greater than 0.9 and less than 1.2). And lithium-containing composite metal oxide; and iron phosphate olivine represented by LiFePO ₄ . Further, as the positive electrode active material, for example, a metal other than lithium represented by S, MnO ₂ , FeO ₂ , FeS ₂ , V ₂ O ₅ , V ₆ O ₁₃ , TiO ₂ , TiS ₂ , MoS ₂ and NbSe ₂ is used. Oxides are also exemplified. Furthermore, conductive polymers represented by polyaniline, polythiophene, polyacetylene, and polypyrrole are also exemplified as the positive electrode active material.

Further, it is preferable to use a lithium-containing compound as the positive electrode active material because a high voltage and a high energy density tend to be obtained. As such a lithium-containing compound, any compound containing lithium may be used. For example, a composite oxide containing lithium and a transition metal element, a phosphate compound containing lithium and a transition metal element, and lithium and a transition metal element (For example, Li _{t Mu} SiO ₄ , where M is as defined in the above formula (6a), t is a number from 0 to 1, and u is a number from 0 to 2). . From the viewpoint of obtaining a higher voltage, lithium, cobalt (Co), nickel (Ni), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), chromium (Cr), vanadium ( V) and composite oxides containing at least one transition metal element selected from the group consisting of titanium (Ti) and phosphate compounds are preferred.

More specifically, the lithium-containing compound is preferably a metal oxide having lithium, a metal chalcogenide having lithium, and a metal phosphate compound having lithium. For example, the lithium-containing compounds are represented by the following general formulas (7a) and (7b), respectively. The compound which is made is mentioned.
^{_{Li v M I O 2 (7a}} )
Li _w M ^II PO ₄ (7b)
Here, in the formula, M ^I and M ^II each represent one or more transition metal elements, and the values of v and w vary depending on the charge / discharge state of the battery, but usually v is 0.05 to 1.10, w Indicates a number from 0.05 to 1.10.

  The compound represented by the general formula (7a) generally has a layered structure, and the compound represented by the general formula (7b) generally has an olivine structure. In these compounds, for the purpose of stabilizing the structure, a part of the transition metal element is substituted with Al, Mg, other transition metal elements or included in the crystal grain boundary, a part of the oxygen atom And those substituted with a fluorine atom or the like. Furthermore, what coat | covered the other positive electrode active material to at least one part of the positive electrode active material surface is mentioned.

  A positive electrode active material is used individually by 1 type or in combination of 2 or more types.

  The number average particle diameter (primary particle diameter) of the positive electrode active material is preferably 0.05 μm to 100 μm, more preferably 1 μm to 10 μm. The number average particle size of the positive electrode active material can be measured by a wet particle size measuring device (for example, a laser diffraction / scattering particle size distribution meter, a dynamic light scattering particle size distribution meter). Alternatively, 100 particles observed with a transmission electron microscope are randomly extracted and analyzed with image analysis software (for example, image analysis software manufactured by Asahi Kasei Engineering Co., Ltd., trade name “A Image-kun”). It can also be obtained by calculating an average. In this case, when the number average particle diameter differs between measurement methods for the same sample, a calibration curve created for the standard sample may be used.

The positive electrode is obtained, for example, as follows. That is, first, a positive electrode mixture-containing paste is prepared by dispersing, in a solvent, a positive electrode mixture obtained by adding a conductive additive, a binder, or the like to the positive electrode active material as necessary. Next, this positive electrode mixture-containing paste is applied to a positive electrode current collector and dried to form a positive electrode mixture layer, which is pressurized as necessary to adjust the thickness, thereby producing a positive electrode.
Here, the solid content concentration in the positive electrode mixture-containing paste is preferably 30 to 80% by mass, and more preferably 40 to 70% by mass.
The positive electrode current collector is made of, for example, a metal foil such as an aluminum foil or a stainless steel foil.

<Negative electrode>
A negative electrode will not be specifically limited if it acts as a negative electrode of a lithium ion secondary battery, A well-known thing may be used. The negative electrode preferably contains at least one material selected from the group consisting of a material capable of inserting and extracting lithium ions as a negative electrode active material and metallic lithium. That is, the negative electrode preferably contains, as the negative electrode active material, one or more materials selected from the group consisting of metallic lithium, a carbon material, a material containing an element capable of forming an alloy with lithium, and a lithium-containing compound. Examples of such materials include lithium metal, hard carbon, soft carbon, artificial graphite, natural graphite, graphite, pyrolytic carbon, coke, glassy carbon, organic polymer compound fired body, mesocarbon microbeads. Carbon materials represented by carbon fiber, activated carbon, graphite, carbon colloid, and carbon black. Among these, examples of the coke include pitch coke, needle coke, and petroleum coke. Further, the fired body of the organic polymer compound is obtained by firing and polymerizing a polymer material such as a phenol resin or a furan resin at an appropriate temperature. In the present invention, a battery employing metallic lithium as the negative electrode active material is also included in the lithium ion secondary battery.

  Further, examples of the material capable of inserting and extracting lithium ions include a material containing an element capable of forming an alloy with lithium. This material may be a single metal or semi-metal, an alloy or a compound, and may have at least a part of one or more of these phases. .

  In the present specification, the “alloy” includes an alloy having one or more metal elements and one or more metalloid elements in addition to an alloy composed of two or more metal elements. In addition, the alloy may have a nonmetallic element as long as the alloy has metallic properties as a whole. In the alloy structure, a solid solution, a eutectic (eutectic mixture), an intermetallic compound, or two or more of these coexist.

  Examples of such metal elements and metalloid elements include titanium (Ti), tin (Sn), lead (Pb), aluminum, indium (In), silicon (Si), zinc (Zn), and antimony (Sb). Bismuth (Bi), gallium (Ga), germanium (Ge), arsenic (As), silver (Ag), hafnium (Hf), zirconium (Zr) and yttrium (Y).

  Among these, metal elements and metalloid elements of Group 4 or 14 in the long-period periodic table are preferable, and titanium, silicon, and tin are particularly preferable.

  As an alloy of tin, for example, as a second constituent element other than tin, silicon, magnesium (Mg), nickel, copper, iron, cobalt, manganese, zinc, indium, silver, titanium (Ti), germanium, bismuth, Examples thereof include those having one or more elements selected from the group consisting of antimony and chromium (Cr).

  Examples of the silicon alloy include, as the second constituent element other than silicon, tin, magnesium, nickel, copper, iron, cobalt, manganese, zinc, indium, silver, titanium, germanium, bismuth, antimony, and chromium. Those having one or more elements selected from the above are listed.

Examples of the titanium compound, the tin compound, and the silicon compound include those having oxygen (O) or carbon (C), and in addition to titanium, tin, or silicon, the second constituent element described above is included. It may be.
Moreover, a lithium containing compound is also mentioned as a material which can occlude and release lithium ions. As the lithium-containing compound, the same compounds as those exemplified as the positive electrode material can be used.

  A negative electrode active material is used individually by 1 type or in combination of 2 or more types.

  The number average particle diameter (primary particle diameter) of the negative electrode active material is preferably 0.1 μm to 100 μm, more preferably 1 μm to 10 μm. The number average particle size of the negative electrode active material is measured in the same manner as the number average particle size of the positive electrode active material.

A negative electrode is obtained as follows, for example. That is, first, a negative electrode mixture-containing paste is prepared by dispersing, in a solvent, a negative electrode mixture prepared by adding a conductive additive or a binder to the negative electrode active material, if necessary. Next, the negative electrode mixture-containing paste is applied to a negative electrode current collector and dried to form a negative electrode mixture layer, which is pressurized as necessary to adjust the thickness, thereby producing a negative electrode.
Here, the solid content concentration in the negative electrode mixture-containing paste is preferably 30 to 80% by mass, and more preferably 40 to 70% by mass.
The negative electrode current collector is made of, for example, a metal foil such as a copper foil, a nickel foil, or a stainless steel foil.

  Examples of the conductive aid used as necessary in the production of the positive electrode and the negative electrode include graphite, carbon black typified by acetylene black and ketjen black, and carbon fiber. The number average particle size (primary particle size) of the conductive assistant is preferably 0.1 μm to 100 μm, more preferably 1 μm to 10 μm, and is measured in the same manner as the number average particle size of the positive electrode active material. Examples of the binder include PVDF, PTFE, polyacrylic acid, styrene butadiene rubber, and fluorine rubber.

<Separator>
The separator according to this embodiment is preferably provided between the positive electrode and the negative electrode from the viewpoint of providing safety such as prevention of short circuit between the positive and negative electrodes and shutdown. An insulating thin film having high ion permeability and excellent mechanical strength is preferred.
Examples of the material of the separator used in this embodiment include ceramic, glass, resin, and cellulose. The resin may be a synthetic resin or a natural resin (natural polymer), and may be an organic resin or an inorganic resin, but from the viewpoint of excellent performance as a separator. An organic resin is preferable. Examples of the organic resin include polyolefin, polyester, polyamide, and heat resistant resins such as liquid crystal polyester and aramid. The material other than the phase transition gelling agent of the separator is preferably ceramic and glass from the viewpoint of high heat resistance, and polyester, polyamide, liquid crystal polyester, aramid, and cellulose are preferable from the viewpoint of handling properties and heat resistance. The material other than the phase transition type gelling agent for the separator is preferably polyolefin from the viewpoint of cost and processability. Among these materials, when a resin is employed, a resin that is a homopolymer may be used, a copolymer resin may be used, or a mixture of a plurality of types of resins and an alloy may be used. Further, the separator may be a laminated body in which films made of a plurality of materials are laminated. When the separator is a laminate, the material of each layer may be the same or different. In the case of manufacturing a separator of a laminated body, it may be manufactured by sequentially stacking a certain layer on another layer, that is, by sequentially multilayering, and a plurality of separate films may be bonded together. Thus, a laminate may be produced.
The form of the separator used in this embodiment is, for example, a synthetic resin microporous film produced by forming a synthetic resin, a fiber spun from a synthetic resin or a natural polymer, a woven fabric processed from glass fiber or ceramic fiber, Nonwoven fabrics, knitted fabrics, papermaking, and films prepared by arranging synthetic resin, ceramic particles, and glass fine particles are listed.
The separator may be obtained by stacking a plurality of films produced by a plurality of production methods, or may be obtained by sequentially multilayering a plurality of production methods.
The separator according to the present embodiment has components other than those described above, for example, organic filler, inorganic filler, organic particles, and inorganic particles, on the surface and / or inside of the separator from the viewpoints of membrane reinforcement, charge / discharge assist, heat resistance improvement, and the like. May be included.

<Battery structure and manufacturing method thereof>
The electrochemical device structure (battery structure) for a lithium ion secondary battery according to the present embodiment only needs to include a battery case (exterior), and the battery case includes a positive electrode, a negative electrode, and a separator. One or more members selected may be further provided, or a part of the electrolytic solution or the electrolytic solution-containing solution may be further provided. For example, the battery structure has a battery shape produced using a positive electrode, a negative electrode, a separator, a battery case (exterior), and other members as necessary. It can be made by known methods.
For example, first, a positive electrode and a negative electrode are wound in a laminated state with a separator interposed therebetween, and formed into a laminated body of a wound structure, or a plurality of them are alternately laminated by bending or laminating a plurality of layers. Or a laminate in which a separator is interposed between the positive electrode and the negative electrode. Subsequently, the laminated body is accommodated in a battery case (exterior), and the battery structure of the lithium ion secondary battery of this embodiment can be produced.

<Method for producing lithium ion secondary battery>
In the battery manufacturing method of the present embodiment, an electrolytic solution-containing solution containing a gelling agent capable of forming a phase transition type gel is injected into the battery structure, and then at least one of the solvents contained in the electrolytic solution-containing solution. A step of removing the portion. As described above, the solvent to be removed preferably has a polar group.

The solvent to be removed preferably has the same or lower boiling point as the solvent remaining in the electrolytic solution after the removing step, and more preferably contains a solvent having a boiling point of 200 ° C. or lower, and 150 ° C. or lower. It is more preferable to include a solvent having a boiling point of, and particularly preferable to include a solvent having a boiling point of 120 ° C. or lower. Such a solvent is easy to remove in the removing step. On the other hand, the solvent to be removed preferably contains a solvent having a boiling point of 40 ° C. or more, more preferably contains a solvent having a boiling point of 50 ° C. or more, and 60 ° C. or more from the viewpoint of excellent handling properties in a normal environment. It is more preferable to include a solvent having a boiling point of
Examples of such solvents include dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate, and chains such as fluorine-containing carbonate in which one or more hydrogen atoms of dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate are substituted with fluorine atoms. Cyclic carbonates such as vinyl carbonate; cyclic ethers such as tetrahydrofuran and substituted or unsubstituted tetrahydrofuran typified by tetrahydrofuran and 2-methyltetrahydrofuran; 1,2-dimethoxyethane, 1,2-diethoxyethane and diglyme, 2, 2,3,3,3-pentafluoropropyl methyl ether, 2,2,3,3,3-pentafluoropropyl-1,1,2,2-tetrafluoroethyl ether, 1,1,2,2-te Lafluoroethyl methyl ether, 1,1,2,2-tetrafluoroethyl ethyl ether, 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoropropyl ether, 1,1,2,2 -Chain ethers such as tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether and hexafluoroisopropyl methyl ether; esters such as acetate represented by ethyl acetate and butyl acetate; acetone and 3-pentanone Ketones; nitriles such as acetonitrile, propionitrile and adiponitrile; halogen-containing solvents such as chloroform and methylene chloride; and aromatic compounds such as toluene, xylene, thiophene, fluorobenzene and hexafluorobenzene. Among these, a chain carbonate and / or a chain ether are preferable, and a chain carbonate is more preferable, from the viewpoint that the allowable amount of the residue that cannot be removed can be set more than other solvents and the removal operation can be simplified.

  In the step of removing at least a part of the solvent contained in the electrolytic solution-containing solution, a method for removing at least a part of the solvent is not particularly limited. For example, the removing step may include a step of heating the electrolytic solution-containing liquid, may include a step of changing the pressure in the battery structure into which the electrolytic solution-containing liquid has been injected, or may include both of these steps. Good. In the step of heating, the electrolyte structure containing liquid accommodated therein may be heated by heating the battery structure into which the electrolyte solution containing liquid has been injected.

When the battery structure is heated in the heating step, the heating means is not particularly limited. For example, a dryer (oven), a vacuum dryer, an inert gas flow dryer, a dry gas flow dryer, an electric heating plate, and a block. A heater can be used.
The heating temperature is preferably 40 ° C. or higher and 200 ° C. or lower, more preferably 50 ° C. or higher and 150 ° C. or lower, and still more preferably 50 ° C. or higher and 120 ° C. or lower. The heating temperature needs to be higher as the boiling point of the solvent to be removed is higher. Further, the heating time is preferably 15 seconds or more and 25 hours or less, and the impregnation property to the battery structure tends to be improved by heating within the range. In addition, it is also possible to raise / lower the temperature of electrolyte solution containing liquid as needed during the process to heat. The battery structure that has undergone the heating step may be cooled to room temperature, and the cooling rate can be arbitrarily selected.

The step of changing the pressure in the battery structure may be a step of reducing the pressure in the battery structure or may be a step of pressurization. However, the viewpoint of manufacturing a battery that more effectively and reliably suppresses the deterioration of the performance. From this, it is preferable to include a step of reducing the pressure.
In the depressurizing step, means for depressurizing the inside of the battery structure is not particularly limited, and for example, a vacuum dryer, a depressurizing furnace, a bell jar, a depressurizing desiccator, and an autoclave can be used. The pressure in the battery structure in this step is not particularly limited as long as it is lower than normal pressure, but is preferably 400 mmHg or less, more preferably 300 mmHg or less. When the pressure is reduced, the pressure may be gradually reduced from the normal pressure, the pressure may be lowered stepwise, and the degree of pressure reduction may be repeated up and down. The number of steps when lowering the pressure stepwise and the number of repetitions when repeating increasing and decreasing the degree of decompression may be two times or three times or more. What is necessary is just to return the inside to the normal pressure of the battery structure which passed through the process of pressure-reducing.
In addition, the battery manufacturing method of the present embodiment may include a step of pressurizing before and after the step of reducing the pressure, and these steps may be repeated alternately.

  Further, in the removing step, the heating step and the depressurizing step may be combined. These steps can be sequentially performed, and in this case, any step may be performed first. Moreover, you may implement simultaneously the process of heating, and the process of pressure-reducing, and in this case, the inside of a battery structure is pressure-reduced, heating an electrolyte solution containing liquid. Alternatively, a plurality of heating steps with different heating conditions may be combined with a plurality of pressure reduction steps with different pressure reduction conditions.

  The amount of the solvent to be removed in the removing step is preferably such that the composition of the solvent, the electrolyte and the gelling agent in the electrolytic solution after removing the solvent is within the above-mentioned preferred range.

  The battery manufacturing method according to the present embodiment includes a step of heating the battery structure, a step of depressurizing the battery structure, and a step of pressurizing the battery structure after the step of removing at least a part of the solvent. At least one step may be included. By passing through these processes, the electrolyte impregnation property to the electrode and separator in a battery structure can improve. At this time, the means for heating, the means for reducing pressure, and the means for applying pressure are not particularly limited.

  The battery manufacturing method of the present embodiment may include a step of injecting a solvent again into the battery structure after the removing step. By passing through this step, it is easy to prepare an electrolytic solution having a desired composition after removing the solvent. The solvent to be reinjected may be the same as or different from the removed solvent.

After passing through the above steps, the remaining members are incorporated into the battery structure as necessary, or when the battery case (exterior) is not completely sealed (sealed), the lithium ion is sealed. A secondary battery can be obtained.
If necessary, the shape may be adjusted, for example, by removing an excess part of the battery, or the battery may be retightened or resealed after the above-described steps.

  In the battery manufacturing method of the present embodiment, when the phase transition gel is injected into the battery structure, it can be injected in a liquid state in which an electrolyte and a gelling agent are dissolved in a solvent. When injected in this manner, the operation can be performed easily because the injection can be performed in the same manner as in the case of using a normal electrolytic solution. In addition, since the impregnation of the battery structure starts immediately after the injection, it is useful in that it can be impregnated in a short time. This method is particularly preferred when the solvent to be removed later is a relatively volatile solvent.

  In the method for producing a battery of this embodiment, when the phase transition gel is injected into the battery structure, it can be injected as a gel-like liquid containing a solvent, an electrolyte, and a gelling agent. This is because the gel is accommodated in a dead space in the battery structure or in a predetermined container previously installed outside the battery structure (for example, immediately above the battery structure) and then removed in the battery structure. This is a method of impregnating the whole. When the gel is housed in a predetermined container installed outside the battery structure, the inside of the container can be pressurized and the gel can be injected from the container into the battery structure. When injected in this manner, the amount of solvent to be removed is small, which is useful in that the solvent can be removed in a short time. This method is particularly preferred when using a gel whose properties (such as transition temperature and strength) vary depending on the amount of solvent in the liquid.

  In the battery manufacturing method of the present embodiment, when the phase transition type gel is injected into the battery structure, it can be injected as a slurry liquid in which the electrolyte is dissolved in the solvent and the gelling agent is dispersed. When injected in this manner, the operation can be performed easily because the injection can be performed in the same manner as a normal liquid electrolyte. Further, when injected in this manner, the amount of solvent to be removed is small, which is useful in that the solvent can be removed in a short time. This method is particularly useful when a gelling agent that is easy to disperse is used.

  The shape of the lithium ion secondary battery of the present embodiment is not particularly limited, and for example, a cylindrical shape, an elliptical shape, a rectangular tube shape, a button shape, a coin shape, a flat shape, and a laminate shape are suitably employed. Among them, a coin type, a cylindrical type, a rectangular tube type, a flat type and a laminate type are more preferably used, and a coin type and a laminate type are particularly preferably used. The battery having such a shape can further increase the affinity between the electrolytic solution and the battery structure, expresses various performances of the gel electrolyte, and is particularly suitable for the battery manufacturing method of the present embodiment. It can be applied easily. Further, the size of the battery is not limited, and a structure in which a plurality of batteries are stacked or arranged can be used in combination with many kinds of batteries. Also, among laminated batteries, the battery case (exterior) is constructed by laminating an aluminum film and a resin like an aluminum laminate material from the viewpoint of lightness, durability, handleability, and cost. Is more preferable.

  As mentioned above, although the manufacturing method of the electrochemical device of this embodiment was explained in detail in the case of manufacturing a lithium ion secondary battery, an electrochemical device is not limited to a lithium ion secondary battery, for example, a solar cell, The method for producing an electrochemical device of the present embodiment can also be applied to the production of secondary batteries, capacitors, and capacitors.

  In the electrochemical device manufacturing method of the present embodiment, an electrochemical device typified by a lithium ion secondary battery can be easily manufactured using a gel electrolyte which is an electrolytic solution excellent in various characteristics such as safety. . In addition, according to the present embodiment, the electrolyte solution can be sufficiently impregnated into a fine space in an electrochemical device structure that is normally difficult to impregnate, and the phase transition type gel electrolyte can be applied at a temperature lower than the phase transition temperature. Since it can be handled, deterioration of the battery member can be suppressed, so that it is possible to prevent a decrease in device performance and obtain desired device characteristics.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to the said embodiment. The present invention can be variously modified without departing from the gist thereof.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples. Various modifications are possible without departing from the scope of the invention. Various characteristics of the lithium ion secondary battery were measured and evaluated as follows.

(I) Evaluation of Sol-Gel Transition Temperature of Electrolyte and Electrolyte-Containing Solution Temperature is raised from 25 ° C. and heating of the electrolyte or electrolyte-containing solution is started, and the temperature is raised for 10 minutes every time the temperature rises by 5 ° C. Stopped. The temperature at which the electrolytic solution or the electrolytic solution-containing solution was completely solated while the temperature increase was stopped was measured as the sol-gel transition temperature.

(Ii) Performance test of lithium ion secondary battery As a lithium ion secondary battery for measurement, a single layer laminate type battery having 1C = 45.0 mA was prepared and used. The measurement was performed using a charge / discharge device ACD-01 (trade name) manufactured by Asuka Electronics Co., Ltd. and a thermostat PLM-63S (trade name) manufactured by Futaba Kagaku Co., Ltd. After charging at a constant current of 9.0 mA and reaching 4.2 V, charging was performed at a constant voltage of 4.2 V for a total of 8 hours. Then, the charge / discharge capacity when discharging to 2.75 V with a constant current of 9.0 mA was measured, and the charge / discharge efficiency was calculated. A battery having a charge capacity of 40 mA or more and a charge / discharge efficiency of 90% or more was evaluated as an acceptable battery, and a battery having a charge capacity of less than 90% was evaluated as an unacceptable battery.

(Iii) Confirmation of state of lithium ion secondary battery After performing the performance test of (ii), disassemble the battery that was rejected in an argon atmosphere, observe the state of the electrode and the separator, and explain the reason for the failure. confirmed.

(Preparation Example 1)
Ethylene carbonate and methyl ethyl carbonate are mixed at a volume ratio of 1: 2, and LiPF ₆ is added to the mixed solution so as to have a concentration of 1 mol / L. The electrolyte solution before the addition of the gelling agent was hereinafter referred to as “mother electrolyte solution”. 3 parts by mass of a compound represented by the following formula (A) as a gelling agent is added to 100 parts by mass of the mother electrolyte (X) and heated to 110 ° C. Mix evenly. The obtained mixed liquid was cooled to 25 ° C. to obtain an electrolytic solution (a).

(Preparation Example 2)
The electrolytic solution (a) prepared in Preparation Example 1 and dimethyl carbonate were mixed at a volume ratio of 1: 1, heated to 70 ° C., and mixed uniformly. The obtained mixed liquid was cooled to 25 ° C. to obtain an electrolytic solution-containing liquid (b).

(Preparation Example 3)
The electrolyte solution (a) prepared in Preparation Example 1 and dimethyl carbonate were mixed at a volume ratio of 1: 4, and heated to 60 ° C. to be uniformly mixed. The obtained mixed liquid was cooled to 25 ° C. to obtain an electrolytic solution-containing liquid (c).

(Preparation Example 4)
3 parts by mass of a compound represented by the following formula (B) as a gelling agent with respect to 100 parts by mass of the mother electrolyte (X) was added to the mother electrolyte (X) prepared in Preparation Example 1, Heat to 0 ° C. to mix uniformly. The obtained mixed liquid was cooled to 25 ° C. to obtain an electrolytic solution (d).

(Preparation Example 5)
The electrolytic solution (d) prepared in Preparation Example 4 and dimethyl carbonate were mixed at a volume ratio of 1: 1, heated to 70 ° C., and mixed uniformly. The obtained mixed liquid was cooled to 25 ° C. to obtain an electrolytic solution-containing liquid (e).

(Preparation Example 6)
The electrolytic solution (d) prepared in Preparation Example 4 and dimethyl carbonate were mixed at a volume ratio of 1: 4, and heated to 60 ° C. to be uniformly mixed. The obtained mixed liquid was cooled to 25 ° C. to obtain an electrolytic solution-containing liquid (f).

(Preparation Example 7)
3 parts by mass of a compound represented by the following formula (C) as a gelling agent is added to 100 parts by mass of the mother electrolyte (X) with respect to the mother electrolyte (X) prepared in Preparation Example 1; Heat to 0 ° C. to mix uniformly. The obtained mixed liquid was cooled to 25 ° C. to obtain an electrolytic solution (g).

(Preparation Example 8)
The electrolytic solution (g) prepared in Preparation Example 7 and dimethyl carbonate were mixed at a volume ratio of 1: 1, heated to 70 ° C., and mixed uniformly. The obtained mixed liquid was cooled to 25 ° C. to obtain an electrolytic solution-containing liquid (h).

(Preparation Example 9)
The electrolytic solution (g) prepared in Preparation Example 7 and dimethyl carbonate were mixed at a volume ratio of 1: 4, and heated to 60 ° C. to be uniformly mixed. The obtained mixed liquid was cooled to 25 ° C. to obtain an electrolytic solution-containing liquid (i).

(Preparation Example 10)
The electrolyte solution (g) prepared in Preparation Example 4 and acetonitrile were mixed at a volume ratio of 1: 4, and heated to 60 ° C. to mix uniformly. The obtained mixed liquid was cooled to 25 ° C. to obtain an electrolytic solution-containing liquid (j).

  The evaluation described in “(i) Evaluation of Sol-Gel Transition Temperature of Electrolytic Solution and Electrolytic Solution-Containing Solution” was performed on the electrolytic solution and the electrolytic solution-containing solution prepared in Preparation Examples 1 to 10. The evaluation results are shown in Table 1.

<Preparation of positive electrode>
Lithium cobalt acid (LiCoO ₂ ) as the positive electrode active material, acetylene black (number average particle size: 42 μm, the same applies hereinafter) as the conductive auxiliary agent, and polyvinylidene fluoride (PVdF) as the binder, 89.5: 4. The mixture was mixed at a mass ratio of 5: 6.0. N-methyl-2-pyrrolidone was further mixed with the obtained mixture to prepare a slurry solution. This slurry solution was applied to an aluminum foil having a thickness of 20 μm and a width of 200 mm, and after removing the solvent by drying, it was rolled with a roll press and further vacuum-dried at 150 ° C. for 10 hours to form a rectangular shape of 50 mm × 30 mm. A positive electrode (ε) was obtained by punching. In addition, about the compound material after the vacuum drying in the obtained electrode, the amount per unit area is 24.8 g / cm ² ± 3%, the thickness on one side is 82.6 μm ± 3%, and the density is 3.0 g / The slurry-like solution was prepared while adjusting the amount of the solvent so that cm ³ ± 3% and the coating width was 150 mm with respect to the width of 200 mm of the aluminum foil.

<Production of negative electrode>
Graphite carbon powder (trade name “MCMB25-28”, manufactured by Osaka Gas Chemical Co., Ltd.) as the negative electrode active material, acetylene black as the conductive additive, and polyvinylidene fluoride (PVdF) as the binder, 93.0: 2 Mixed at a mass ratio of 0.0: 5.0. N-methyl-2-pyrrolidone was further mixed with the obtained mixture to prepare a slurry solution. This slurry-like solution was applied to an aluminum foil having a thickness of 14 μm and a width of 200 mm, and the solvent was removed by drying, followed by rolling with a roll press, followed by vacuum drying at 150 ° C. for 10 hours, and punching out to 52 mm × 32 mm. (Ζ) was obtained. In addition, about the compound material after the vacuum drying in the obtained electrode, the amount per unit area is 11.8 g / cm ² ± 3%, the thickness on one side is 84.6 μm ± 3%, and the density is 1.4 g / The slurry-like solution was prepared while adjusting the amount of the solvent so that cm ³ ± 3% and the coating width was 150 mm with respect to the width of 200 mm of the aluminum foil.

Example 1
Using the electrolytic solution-containing solution (b) prepared in Preparation Example 1, a laminate battery of 1C = 45.0 mA was produced as follows. First, two laminated films (non-drawn, rectangular, thickness 120 μm, 68 mm × 48 mm) laminated with an aluminum layer and a resin layer, with the aluminum layer side facing outward (that is, the resin layers facing each other) The laminate cell exterior (battery case) was produced by overlapping and sealing the three sides. Subsequently, a polypropylene microporous film (film thickness: 25 μm, air permeability: 200 seconds) was prepared as a separator, and a plurality of positive electrodes (ε) and negative electrodes (ζ) produced as described above were alternately provided via the separators. The stacked laminate was placed at a predetermined position in the laminate cell exterior to obtain a battery structure (X). Next, a gel electrolyte solution containing liquid (b) was injected at 25 ° C. into the cell exterior of the battery structure (X). Next, after sealing the remaining one side of the cell exterior so that it could be opened, it was heated at 70 ° C. for 20 minutes using an oven under normal pressure. Thereafter, the battery structure containing the electrolytic solution-containing liquid (b) is taken out of the oven, and in a state where the temperature is high and quickly sandwiched between heating plates and maintained at 70 ° C., one side of the cell exterior that can be opened is opened. While holding the battery between the heating plates, the pressure inside the battery structure was reduced to 100 mmHg using a vacuum desiccator (hereinafter, this pressure is referred to as “reduced pressure”). After reaching the reduced pressure, the air was returned to normal pressure by introducing dry air into the vacuum desiccator, and the operation of reducing the pressure again and the operation of returning to the normal pressure were performed. Thereafter, the battery structure was kept at 100 mmHg and 70 ° C. for a while, and dimethyl carbonate was removed by volatilization to obtain an electrolytic solution. Thereafter, the battery structure containing the electrolytic solution (the composition corresponding to the electrolytic solution (a)) is cooled to 25 ° C., and unnecessary portions of the cell exterior are cut and removed, and then the one side of the cell exterior is sealed again. As a result, a lithium ion secondary battery (b) was obtained. About the obtained lithium ion secondary battery (b), evaluation as described in said "(ii) Performance test of a lithium ion secondary battery" was implemented. The results are shown in Table 2.

(Example 2)
A liquid electrolyte solution-containing liquid (c) was injected at 25 ° C. into the cell exterior of the battery structure (X) produced in the same manner as in Example 1. Next, in a state where one side of the cell exterior is opened, the battery structure containing the electrolytic solution-containing liquid (c) is decompressed using a vacuum desiccator until the battery structure becomes 100 mmHg (hereinafter referred to as pressure here). Is referred to as “reduced pressure”). After reaching the reduced pressure, the air was returned to normal pressure by introducing dry air into the vacuum desiccator, and the operation of reducing the pressure again and the operation of returning to the normal pressure were performed. Thereafter, the battery structure was depressurized to 300 mmHg, and was heated to 70 ° C. by being sandwiched between heating plates, and kept under those conditions to volatilize and remove dimethyl carbonate to obtain an electrolytic solution. Thereafter, the battery structure including the electrolytic solution (the composition corresponding to the electrolytic solution (a)) is cooled to 25 ° C., and unnecessary portions of the cell exterior are cut and removed, and then the one side of the cell exterior is sealed again. Thus, a lithium ion secondary battery (c) was obtained. About the obtained lithium ion secondary battery (c), evaluation as described in said "(ii) Performance test of a lithium ion secondary battery" was implemented. The results are shown in Table 2.

(Example 3)
A gel-like electrolyte solution-containing solution (e) was injected at 25 ° C. into the cell exterior of the battery structure (X) produced in the same manner as in Example 1. Next, after sealing the remaining one side of the cell exterior so that it could be opened, it was heated at 70 ° C. for 20 minutes using an oven under normal pressure. Thereafter, the battery structure containing the electrolytic solution-containing liquid (e) is taken out of the oven, and in a state where the temperature is high and quickly sandwiched between heating plates and maintained at 70 ° C., one side of the cell exterior that can be opened is opened. While holding the battery between the heating plates, the pressure inside the battery structure was reduced to 100 mmHg using a vacuum desiccator (hereinafter, this pressure is referred to as “reduced pressure”). After reaching the reduced pressure, the air was returned to normal pressure by introducing dry air into the vacuum desiccator, and the operation of reducing the pressure again and the operation of returning to the normal pressure were performed. Thereafter, the battery structure was kept at 100 mmHg and 70 ° C. for a while, and dimethyl carbonate was removed by volatilization to obtain an electrolytic solution. Thereafter, the battery structure including the electrolytic solution (the composition corresponding to the electrolytic solution (d)) is cooled to 25 ° C., and unnecessary portions of the cell exterior are cut and removed, and then the one side of the cell exterior is sealed again. Thus, a lithium ion secondary battery (e) was obtained. About the obtained lithium ion secondary battery (e), evaluation as described in the above "(ii) Performance test of lithium ion secondary battery" was implemented. The results are shown in Table 2.

Example 4
A liquid electrolyte solution containing liquid (f) was injected at 25 ° C. into the cell exterior of the battery structure (X) produced in the same manner as in Example 1. Next, in a state where one side of the cell exterior is opened, the battery structure containing the electrolytic solution-containing liquid (f) is decompressed using a vacuum desiccator until the battery structure becomes 100 mmHg (hereinafter referred to as pressure here). Is referred to as “reduced pressure”). After reaching the reduced pressure, the air was returned to normal pressure by introducing dry air into the vacuum desiccator, and the operation of reducing the pressure again and the operation of returning to the normal pressure were performed. Thereafter, the battery structure was sandwiched between heating plates and heated to 80 ° C., and maintained at that temperature to evaporate dimethyl carbonate to obtain an electrolytic solution. Thereafter, the battery structure including the electrolytic solution (the composition corresponding to the electrolytic solution (d)) is cooled to 25 ° C., and unnecessary portions of the cell exterior are cut and removed, and then the one side of the cell exterior is sealed again. Thus, a lithium ion secondary battery (f) was obtained. About the obtained lithium ion secondary battery (f), evaluation as described in said "(ii) Performance test of a lithium ion secondary battery" was implemented. The results are shown in Table 2.

(Example 5)
A gel-like electrolyte solution-containing solution (h) was injected at 25 ° C. into the cell exterior of the battery structure (X) produced in the same manner as in Example 1. Next, after sealing the remaining one side of the cell exterior so that it could be opened, it was heated at 70 ° C. for 20 minutes using an oven under normal pressure. Thereafter, the battery structure containing the electrolytic solution-containing liquid (h) is taken out of the oven, and the one side sealed to be able to open the cell exterior is opened in a state where the temperature is high and the temperature is quickly sandwiched between heating plates. While holding the battery between the heating plates, the pressure inside the battery structure was reduced to 100 mmHg using a vacuum desiccator (hereinafter, this pressure is referred to as “reduced pressure”). After reaching the reduced pressure, the air was returned to normal pressure by introducing dry air into the vacuum desiccator, and the operation of reducing the pressure again and the operation of returning to the normal pressure were performed. Thereafter, the battery structure was kept at 100 mmHg and 80 ° C. for a while, and dimethyl carbonate was volatilized to obtain an electrolytic solution. Thereafter, the battery structure including the electrolytic solution (with a composition corresponding to the electrolytic solution (g)) is cooled to 25 ° C., and unnecessary portions of the cell exterior are cut and removed, and then the one side of the cell exterior is sealed again. Thus, a lithium ion secondary battery (h) was obtained. About the obtained lithium ion secondary battery (h), evaluation as described in the above "(ii) Performance test of lithium ion secondary battery" was implemented. The results are shown in Table 2.

(Example 6)
A liquid electrolyte-containing solution (i) in a liquid state was injected at 25 ° C. into the cell exterior of the battery structure (X) produced in the same manner as in Example 1. Next, in a state where one side of the cell exterior is opened, the battery structure containing the electrolytic solution-containing liquid is depressurized using a vacuum desiccator until the battery structure reaches 100 mmHg (hereinafter, the pressure is referred to as “reduced pressure”). Pressure ”). After reaching the reduced pressure, the air was returned to normal pressure by introducing dry air into the vacuum desiccator, and the operation of reducing the pressure again and the operation of returning to the normal pressure were performed. Thereafter, the battery structure was depressurized to 400 mmHg, and heated to 80 ° C. with a heating plate, and kept at that temperature to evaporate dimethyl carbonate to obtain an electrolytic solution. Thereafter, the battery structure including the electrolytic solution (with a composition corresponding to the electrolytic solution (g)) is cooled to 25 ° C., and unnecessary portions of the cell exterior are cut and removed, and then the one side of the cell exterior is sealed again. Thus, a lithium ion secondary battery (i) was obtained. About the obtained lithium ion secondary battery (i), evaluation as described in the above "(ii) Performance test of lithium ion secondary battery" was implemented. The results are shown in Table 2.

(Example 7)
A gel-like electrolyte solution-containing solution (b) was injected at 25 ° C. into the cell exterior of the battery structure (X) produced in the same manner as in Example 1. Next, after sealing the other side of the cell exterior so that it could be opened, it was heated at 90 ° C. for 2 hours using an oven under normal pressure to volatilize dimethyl carbonate to obtain an electrolyte. Thereafter, the battery structure including the electrolytic solution (the composition corresponding to the electrolytic solution (a)) is cooled to 25 ° C., and unnecessary portions of the cell exterior are cut and removed, and then the one side of the cell exterior is sealed again. Thus, a lithium ion secondary battery (b ′) was obtained. The obtained lithium ion secondary battery (b ′) was evaluated as described in “(ii) Performance test of lithium ion secondary battery”. The results are shown in Table 2.

(Example 8)
A liquid electrolyte solution-containing liquid (c) was injected at 25 ° C. into the cell exterior of the battery structure (X) produced in the same manner as in Example 1. Next, in a state where one side of the cell exterior is opened, the battery structure containing the electrolytic solution-containing liquid (c) is decompressed using a vacuum desiccator until the battery structure becomes 100 mmHg (hereinafter referred to as pressure here). Is referred to as “reduced pressure”). After reaching the reduced pressure, the air was returned to normal pressure by introducing dry air into the vacuum desiccator, and the operation of reducing the pressure again and the operation of returning to the normal pressure were performed. Thereafter, the battery structure was depressurized to 300 mmHg, heated to 75 ° C. with a heating plate, held under the conditions, and dimethyl carbonate was volatilized and 10% of ethyl methyl carbonate was removed. Thereafter, the same amount of ethyl methyl carbonate as the removed ethyl methyl carbonate was introduced into the cell to obtain an electrolytic solution. Then, after cooling the battery structure including the electrolytic solution (having a composition corresponding to the electrolytic solution (a)) to 25 ° C., cutting and removing unnecessary portions of the cell exterior, the one side of the cell exterior is sealed again. Thus, a lithium ion secondary battery (c ′) was obtained. The obtained lithium ion secondary battery (c ′) was evaluated as described in “(ii) Performance test of lithium ion secondary battery”. The results are shown in Table 2.

Example 9
A liquid electrolyte solution-containing solution (j) at 25 ° C. was injected into the cell exterior of the battery structure (X) produced in the same manner as in Example 1. Next, in a state where one side of the cell exterior is opened, the battery structure containing the electrolyte solution-containing liquid (j) is decompressed using a vacuum desiccator until the battery structure becomes 100 mmHg (hereinafter referred to as pressure here). Is referred to as “reduced pressure”). After reaching the reduced pressure, the air was returned to normal pressure by introducing dry air into the vacuum desiccator, and the operation of reducing the pressure again and the operation of returning to the normal pressure were performed. Thereafter, the battery structure was sandwiched between heating plates and heated to 80 ° C., and maintained at that temperature to evaporate dimethyl carbonate to obtain an electrolytic solution. Thereafter, the battery structure including the electrolytic solution (the composition corresponding to the electrolytic solution (j)) is cooled to 25 ° C., and unnecessary portions of the cell exterior are cut and removed, and then the one side of the cell exterior is sealed again. Thus, a lithium ion secondary battery (j) was obtained. About the obtained lithium ion secondary battery (j), evaluation as described in said "(ii) Performance test of lithium ion secondary battery" was implemented. The results are shown in Table 2.

(Comparative Example 1)
The gel electrolyte solution (a) was injected at 25 ° C. into the cell exterior of the battery structure (X) produced in the same manner as in Example 1. Next, after sealing the remaining one side of the cell exterior so that it could be opened, it was heated at 70 ° C. for 1 hour using an oven under normal pressure. Thereafter, the battery structure containing the electrolytic solution (a) is taken out of the oven, and is held at 70 ° C. by sandwiching it between the heating plates. Using a vacuum desiccator, the pressure inside the battery structure was reduced to 100 mmHg (hereinafter, the pressure is referred to as “reduced pressure”). After reaching the reduced pressure, the air was returned to normal pressure by introducing dry air into the vacuum desiccator, and the operation of reducing the pressure again and the operation of returning to the normal pressure were performed. Thereafter, the battery structure containing the electrolytic solution was cooled to 25 ° C., and unnecessary portions of the cell exterior were cut and removed, and then the one side of the cell exterior was sealed again to obtain a lithium ion secondary battery (a ′). . The obtained lithium ion secondary battery (a ′) was evaluated as described in “(ii) Performance test of lithium ion secondary battery”. The results are shown in Table 2.

(Comparative Example 2)
A gel electrolyte solution (g) was injected at 25 ° C. into the cell exterior of the battery structure (X) produced in the same manner as in Example 1. Next, after sealing the remaining one side of the cell exterior so that it could be opened, it was heated at 100 ° C. for 1 hour using a normal pressure oven. Thereafter, the battery structure containing the electrolytic solution (g) is taken out from the oven, and is held at 100 ° C. by sandwiching it between the heating plates. Using a vacuum desiccator, the pressure inside the battery structure was reduced to 100 mmHg (hereinafter, the pressure is referred to as “reduced pressure”). After reaching the reduced pressure, the air was returned to normal pressure by introducing dry air into the vacuum desiccator, and the operation of reducing the pressure again and the operation of returning to the normal pressure were performed. Thereafter, the battery structure containing the electrolytic solution was cooled to 25 ° C., and unnecessary portions of the cell exterior were cut and removed, and then the one side of the cell exterior was sealed again to obtain a lithium ion secondary battery (g ′). . The obtained lithium ion secondary battery (g ′) was evaluated as described in “(ii) Performance test of lithium ion secondary battery”. The results are shown in Table 2.

  Regarding the lithium ion secondary battery (a ′) obtained in Comparative Example 1 and the lithium ion secondary battery (g ′) obtained in Comparative Example 2, the charged / discharged battery was disassembled, and “(iii) lithium "Confirmation of the state of the ion secondary battery" was carried out. The results are shown in Table 3.

  The method for producing an electrochemical device of the present invention is useful when producing electrochemical devices such as solar cells, secondary batteries, capacitors and capacitors, and is preferably used for batteries and capacitors, particularly lithium ion secondary batteries. It has industrial applicability as a manufacturing method.

Claims (10)

  A method for producing an electrochemical device using an electrolytic solution containing a gelling agent that is gel-like at 25 ° C. and can form a phase transition type gel that becomes a sol when heated, the solution or dispersion containing the electrolytic solution A method for producing an electrochemical device, comprising the step of removing at least a part of the solvent contained in the solution or dispersion after injecting the solution into the electrochemical device structure.   The method for producing an electrochemical device according to claim 1, wherein the solvent to be removed includes a solvent having a boiling point of 200 ° C. or less.   The method for producing an electrochemical device according to claim 1, wherein the solvent to be removed includes at least one of a chain carbonate solvent and a nitrile solvent.   The method for producing an electrochemical device according to any one of claims 1 to 3, wherein the solution or dispersion is a liquid in which an electrolyte and the gelling agent are dissolved in a solvent.   The method for producing an electrochemical device according to any one of claims 1 to 3, wherein the solution or dispersion is a gelled liquid containing a solvent, an electrolyte, and a gelling agent.   The method for producing an electrochemical device according to any one of claims 1 to 3, wherein the solution or dispersion is a slurry-like liquid in which an electrolyte is dissolved in a solvent and a gelling agent is dispersed.   The method for producing an electrochemical device according to claim 1, wherein the removing step includes a step of heating the solution or the dispersion.   The method for producing an electrochemical device according to claim 1, wherein the removing step includes a step of changing a pressure in the electrochemical device structure into which the solution or dispersion is injected.   The method for producing an electrochemical device according to any one of claims 1 to 8, wherein the solution or dispersion subjected to the removing step is in a gel form.   The method for producing a lithium ion secondary battery according to claim 1, wherein the gelling agent is a low molecular weight type gelling agent.