JP2013069682A - Method for manufacturing electrochemical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an electrochemical device typified by a lithium ion secondary battery including a gel electrolyte, which does not deteriorate device performance and is simplified.SOLUTION: In an electrochemical device, a phase transition type gel which is gelatinous at 25°C and transformed into a sol state when heated is used as an electrolyte. A method for manufacturing the electrochemical device includes a pressure changing step of changing pressure in an electrochemical device structure in which the electrolyte has been injected.

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-mentioned object, the present inventors have studied various electrochemical device fabrication processes using various gel electrolytes. As a result, the phase transition type gel was used as an electrolytic solution, and the electrolytic solution was used as an internal part of the electrochemical device. It has been found that an electrochemical device having excellent device characteristics can be formed by using a step of changing the pressure for impregnation into the solution, and the present invention has been completed.

That is, the present invention is as follows.
[1] A method of manufacturing an electrochemical device using a phase transition type gel that is gelled at 25 ° C. and becomes a sol when heated as an electrolytic solution, in the electrochemical device structure into which the electrolytic solution is injected The manufacturing method of an electrochemical device including the pressure change process which changes a pressure.
[2] The method for manufacturing an electrochemical device according to [1], wherein the pressure changing step includes a step of decompressing the inside of the electrochemical device structure into which the electrolytic solution has been injected.
[3] The method for manufacturing an electrochemical device according to [1] or [2], wherein the pressure changing step includes a step of pressurizing the electrochemical device structure into which the electrolytic solution is injected.
[4] The manufacturing of the electrochemical device according to any one of [1] to [3], including an injection step of injecting the electrolytic solution into the electrochemical device structure before the pressure change step. Method.
[5] The method for manufacturing an electrochemical device according to [4], wherein the electrolyte to be injected in the injection step is in a sol state.
[6] The method for manufacturing an electrochemical device according to [4], wherein the electrolytic solution to be injected in the injection step is in a gel state.
[7] The electrochemical device according to any one of [1] to [6], wherein the phase transition type gel includes a gelling agent, and the gelling agent is a low molecular weight type gelling agent. Production method.
[8] Any one of [1] to [7], wherein the phase transition type gel contains a compound having an unsaturated bond (excluding an unsaturated bond in C = O) and / or a fluorine atom. The manufacturing method of the electrochemical device as described in one.
[9] The method for producing an electrochemical device according to any one of [1] to [8], wherein an exterior of the electrochemical device is made of an aluminum laminate material.

  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 method for manufacturing an electrochemical device according to the present embodiment is a method for manufacturing an electrochemical device using a phase transition type gel as an electrolyte, and is a pressure that changes the pressure in the electrochemical device structure into which the electrolyte is injected. It includes a change process. In the pressure changing step, the electrochemical device structure may be depressurized, pressurized, or both may be sequentially performed. Further, the pressure may be reduced or increased twice or more, and the reduced pressure and the increased pressure may be alternately performed in two or more cycles. Here, as long as the “electrochemical device structure” includes an electrochemical device exterior for housing each member of the electrochemical device, the interior of the exterior is not particularly limited. For example, the electrochemical device structure may include an electrode of the electrochemical device in the exterior. The “structure” refers to a space in the exterior of the electrochemical device.

<Phase transition type gel>
The phase transition type gel according to this embodiment is a gel that undergoes a phase transition between sol and gel due to temperature change, and more specifically, is a gel at 25 ° C. and becomes a sol when heated. If it is, it will not specifically limit. From the viewpoint of more effectively and reliably solving the problems of the present invention, the phase transition type gel preferably contains (I) a nonaqueous solvent, (II) an electrolyte, and (III) a gelling agent.
(I) 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 and the like. Acid esters, dimethyl ketone, diethyl ketone, methyl ethyl ketone, ketones such as 3-pentanone and acetone, hydrocarbons such as pentane, hexane, octane, cyclohexane, benzene, toluene, xylene, fluorobenzene and hexafluorobenzene, diethyl Ethers, 1,2-dimethoxyethane, 1,4-dioxane, crown ethers, glymes, ethers such as tetrahydrofuran and fluoroalkyl ether, N, N-dimethylacetoa Amides such as N, N-dimethylformamide, ethylenediamine and pyridine, carbonates such as propylene carbonate, ethylene carbonate, vinylene carbonate, fluoroethylene carbonate, diethyl carbonate and ethyl methyl carbonate, acetonitrile, propionitrile, adiponitrile, methoxy Nitriles such as acetonitrile, lactams such as N-methylpyrrolidone (NMP), sulfones such as sulfolane, sulfoxides such as dimethyl sulfoxide, industrial oils such as silicon oil and petroleum, and edible oils.

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.

  In the case where the electrochemical device is a lithium ion secondary battery or a lithium ion capacitor, examples of the non-aqueous solvent include an aprotic solvent, and the electrolyte solution of the lithium ion secondary battery is preferably an aprotic polar solvent. 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 typified by pentylene carbonate, cis-2,3-pentylene carbonate, trifluoromethylethylene carbonate, fluoroethylene carbonate and 4,5-difluoroethylene carbonate; typified by γ-butyrolactone and γ-valerolactone Lactone; cyclic sulfone represented by sulfolane; cyclic ether represented by tetrahydrofuran and dioxane; methyl ethyl carbonate, dimethyl carbonate, diethyl carbonate, methyl propyl carbonate Bonates, methyl isopropyl carbonate, dipropyl carbonate, methyl butyl carbonate, dibutyl carbonate, ethyl propyl carbonate and chain carbonate represented by methyl trifluoroethyl carbonate; nitrile represented by acetonitrile; chain ether represented by dimethyl ether; Examples thereof include a chain carboxylic acid ester represented by methyl propionate; a chain ether carbonate compound represented by dimethoxyethane. 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.

(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 lithium difluoro oxalyl borate represented by _{(C 2 O 2), LiPF} 3 lithium trifluoromethane oxalyl phosphate represented by (C ₂ O _2), it includes _{LiPO 2 F 2, L 2 PO} 3 F.

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, but the electrolyte is preferably contained in the electrolytic solution at a concentration of 0.1 to 3 mol / liter, more preferably 0.5 to 2 mol / liter.

  (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 non-aqueous 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), a copolymer containing PVdF (for example, a copolymer of PVdF and hexafluoropropylene), and polyacrylonitrile (PAN). ) And a copolymer containing a PAN site (for example, a copolymer of acrylonitrile and (meth) acrylic acid ester). Examples of the low molecular weight type gelling agent include compounds described in “Chem. Rev. Vol. 97, p3133-p3159, issued in 1997”, compounds described in JP-A-10-175901, The compound described in the international publication 2006/82768, the compound described in Unexamined-Japanese-Patent No. 2007-506833, and the compound described in Unexamined-Japanese-Patent No. 2009-155592 are mentioned.

  The phase transition type gelling agent is preferably a compound whose phase transition temperature between the gel and the sol is 40 ° C. or higher and 200 ° C. or lower in the electrolytic solution containing it. When the phase transition temperature is within the range, the handling properties and battery characteristics of the electrolyte can be compatible at a higher level.

  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”. This divalent aromatic group may be a monocyclic group or a heterocyclic group. The monocyclic 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”. The divalent aromatic hydrocarbon group may be a monocyclic 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 monocyclic group has 6-30 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 is a group in which a plurality of groups are connected if the number of nuclear atoms is within the range, or both a simple ring and a heterocyclic ring are included, or an aromatic group And 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 includes the nonaqueous solvent in which the compound represented by the general formula (3) (hereinafter also referred to as “compound (3)”) is dissolved in the nonaqueous solvent. In order to make the electrolytic solution gel, it is preferably a hydrocarbon group such as an aralkyl group typified by a benzyl group that allows the compound (3) to be easily dissolved in a non-aqueous solvent. 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（４Ｉ）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 (4I). 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 this embodiment in the phase transition type gel is not particularly limited as long as it is an amount capable of gelling the electrolytic solution. However, from the viewpoint of improving handling properties, characteristics as an electrochemical device, and low cost in a well-balanced manner, the content is 0.01 to 20 parts by mass relative to 100 parts by mass of the total amount of the nonaqueous solvent and the electrolyte. And preferably 0.1 to 10 parts by mass.

The phase transition type gel according to this embodiment may further contain an additive as necessary. Examples of additives include a heat stabilizer, a flame retardant, a thermal runaway inhibitor, an overcharge suppression additive, a thickener, an emulsifier, a strengthening agent, a wetting agent, an electrode protection additive, and water and acid are removed. An additive is mentioned. 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 in 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, but achieves both good battery characteristics and the effect of the additive. Therefore, the content of the additive is preferably 0.01 parts by mass to 20 parts by mass, more preferably 0.5 parts by mass to 15 parts by mass with respect to 100 parts by mass of the total amount of the nonaqueous solvent and the electrolyte. 1 mass part-10 mass parts are still more preferable.
When the phase transition type gel according to this embodiment is used as an electrolyte for a lithium ion secondary battery, gas generation during battery preparation and charge / discharge is reduced, or stable charge / discharge is performed over a long period of time. Therefore, it is effective to use a compound having an unsaturated bond (excluding an unsaturated bond in C = O) and / or a fluorine atom as an additive for electrode protection. The unsaturated bonds other than those at C = O are not particularly limited as long as they have polymerizability. Examples of the compound having an unsaturated bond (excluding an unsaturated bond in C = O) and / or a fluorine atom include, for example, an alkene that is a part of a carbonate compound often used in a solvent of an electrolytic solution, 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 in C═O) and / or a fluorine atom include vinylene carbonate, vinyl ethylene carbonate, diallyl carbonate, fluoroethylene carbonate, Examples thereof include ethylene sulfite, propylene sulfite, 1,3-propane sultone, 1,4-butane sultone, succinonitrile, adiponitrile, and malononitrile. The additive for forming a film is preferably contained in an amount of 0.01 to 20 parts by mass, more preferably 0.5 to 15 parts by mass with respect to 100 parts by mass of the total amount of the nonaqueous solvent and the electrolyte. More preferably, 1 part by mass to 10 parts by mass are included. An additive is used individually by 1 type or in combination of 2 or more types, For example, the additive which assists electrode protection can also be added further.

  The phase transition temperature from the gel to the sol of the phase transition type gel is preferably between 40 ° C. and 200 ° C., more preferably 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 battery fabrication can be more effectively achieved.

  The mixing ratio of the non-aqueous solvent, the electrolyte, and the gelling agent can be selected according to the purpose, but it is desirable that all of the electrolyte concentration and the gelling agent content are within the above-mentioned preferable range, and more preferable range. By preparing the electrolytic solution with such a composition, all of battery characteristics, handleability and safety can be further improved.

The method for preparing the electrolytic 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 includes a nonaqueous solvent, an electrolyte, and a gelling agent, the order of mixing the electrolyte, the nonaqueous solvent, and the gelling agent is not limited. More specifically, after preparing a preliminary electrolyte by mixing a predetermined amount of electrolyte and a non-aqueous solvent, a gelling agent can be mixed in the preliminary electrolyte to obtain the electrolyte of the present embodiment. . Alternatively, it is possible to obtain the electrolytic solution of the present embodiment by mixing all the components in a predetermined amount at the same time. In addition, the preparation method of electrolyte solution will obtain a more uniform gel over the whole electrolyte solution, if a mixture containing a gelatinizer is heated once and it cools to room temperature in the state in which each component in a mixture became uniform. From the viewpoint of being able to do so. From such a viewpoint, the heating temperature of the mixture is preferably equal to or higher than the transition temperature from the gel to the sol of the generated phase transition type gel.
As is apparent from the above, the electrolytic solution of the present embodiment is a phase transition type gel electrolyte and is preferably used in a lithium ion secondary battery.

  The electrochemical device manufacturing method of the present embodiment may include a step of injecting the electrolyte solution into the electrochemical device structure prepared in advance before the pressure changing step, or a reduced pressure state in advance. There may be a step of injecting the electrolyte solution into the electrochemical device structure, and the step of injecting the electrolyte solution and the step of changing the pressure are alternately repeated a plurality of times to inject the electrolyte solution step by step. May be.

  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 have an electrochemical device exterior, and the positive electrode is included in the exterior. One or more members selected from the group consisting of a negative electrode and a separator may be further provided, and a part of the electrolytic solution may be further provided. 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 formed by sequentially forming a layer on another layer, that is, by sequentially multilayering, and a plurality of films prepared separately 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 selected members may be further provided, or a part of the electrolytic 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 to be formed into a cylindrical structure, or they are bent into a rectangular tube structure, or the positive electrode, the separator, and the negative electrode Are laminated in a single layer or a plurality of layers to form a laminate in which separators are interposed between a plurality of alternately stacked positive and negative electrodes. 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>
The battery manufacturing method of the present embodiment includes a pressure changing step of changing the pressure in the battery structure into which the phase transition type gel, which is an electrolytic solution, is injected.
The battery manufacturing method of the present embodiment may include a step of injecting a part or all of the electrolytic solution in a gel or sol state into the battery structure prior to the pressure changing step. The injection method of the electrolytic solution may be a known method.
The battery manufacturing method of the present embodiment preferably includes a step of heating the battery structure containing the gel after injecting the gel into the battery structure. By heating, the gel structure can be more sufficiently impregnated into the battery structure. In addition, it is preferable that the temperature to heat is more than the temperature which is 10 degreeC lower than the phase transition temperature of a phase transition type gel. In the said temperature range, a gel becomes easy to show fluidity | liquidity and the impregnation property to a battery structure further improves. From the same viewpoint, the heating temperature is more preferably 5 ° C. or more below the phase transition temperature of the phase transition gel. Moreover, it is preferable that the temperature to heat is below the said phase transition temperature 20 degreeC or less from a viewpoint of handling property. In particular, the temperature to be heated is preferably not less than 5 ° C. below the phase transition temperature and not more than 10 ° C. below the phase transition temperature. When the heating is performed within the temperature range, the balance between the gel impregnation property and the handling property becomes better.

The heating time is preferably from 30 seconds to 25 hours, more preferably from 1 minute to 10 hours. By setting the heating time within this range, the gel can be more sufficiently impregnated into the battery structure even in a simple process. It is also possible to raise or lower the temperature as necessary during heating. The battery structure that has finished heating is cooled to room temperature. In addition, the cooling rate at the time of cooling can be selected arbitrarily.
Various known methods can be selected as the heating method. Specifically, the battery structure is housed in an oven, dryer, vacuum dryer, inert gas atmosphere flow dryer, thermostat, etc., and heated in a heated gas environment. The battery structure is oil bath, water Examples thereof include a method of immersing in a bath or the like and heating in a heated liquid environment, a method of heating the battery structure in contact with a heating plate or a heating block, and the like.
The step of heating may be performed prior to the pressure changing step, may be performed simultaneously with the pressure changing step, or the step of heating and the pressure changing step may be alternately repeated a plurality of times.

  In the battery manufacturing method of the present embodiment, when injecting the phase transition type gel into the battery structure, the gel can be preliminarily heated to be in a sol state before injection. By injecting in this manner, the injection operation can be further facilitated because the injection can be performed in the same manner as a normal liquid electrolyte. In addition, since the impregnation of the battery structure starts immediately after the injection, such an injection method is useful in that it can be impregnated in a short time. In particular, when using a phase transition type gel with a relatively low phase transition temperature, when using a low-volatility electrolyte solution solvent, a heat-resistant electrolyte and other battery members, It is valid.

  In the battery manufacturing method of the present embodiment, when a phase transition type gel is injected into the battery structure, it can also be injected in a gel state. As a method of injecting in a gel state, for example, first, the gel is accommodated in a dead space in the battery structure, or a predetermined container previously installed outside the battery structure (for example, directly above the battery structure), and then This is a method of impregnating the entire battery structure with the gel. When the gel is accommodated in a predetermined container installed outside the battery structure, the gel is then put into the battery structure from the container by pressurizing the container or depressurizing the battery structure. The gel accommodated in the battery structure by these methods is heated together with the battery structure, so that the gel can be uniformly impregnated in the entire battery structure. By injecting in this way, the electrolyte solution can be injected at room temperature or with low heating, and the heating time can be shortened or the battery structure can be impregnated with simple equipment. It is useful in that. Such a method is effective when a phase transition type gel having a relatively high phase transition temperature is used. Furthermore, it is also useful when using a solvent in an electrolytic solution that easily volatilizes when heated, or an electrolyte or battery member that easily deteriorates when heated.

The battery manufacturing method of the present embodiment includes a pressure changing step of changing the pressure in the battery structure after injecting the electrolyte into the battery structure. In this step, the inside of the battery structure may be depressurized (this case is referred to as a “depressurization step”) or pressurized (this case is referred to as a “pressurization step”).
When the pressure inside the battery structure is reduced, the battery structure can be sufficiently impregnated with the electrolyte in a short time by using the pressure difference from before the pressure reduction. In addition, the battery manufacturing method of the present embodiment may further include a step of returning the battery structure to normal pressure after decompression, and using the pressure difference, the electrolyte is further applied to the battery structure in a short time. It can be sufficiently impregnated. In addition, it is effective to go through a decompression step in that the gas in the battery structure can be replaced with the electrolyte solution in a short time, and in the case of a laminated battery, the thickness and shape of the battery can be easily adjusted. Note that the operation of depressurizing the battery structure and returning it to normal pressure may be repeated a plurality of times. Moreover, the pressure reduction step and the step of returning to normal pressure may overlap with the step of heating. In other words, the pressure reduction may be started before the end of heating after the start of heating, the heating may be started before the end of the pressure reduction after starting the pressure reduction, or the heating and the pressure reduction may be started simultaneously. Even if the heating is finished after the start of decompression, the decompression is finished (starting to return to normal pressure), but the decompression is finished (starting to return to normal pressure) after the start of heating, and then the heating is finished. Alternatively, heating and decompression may be terminated at the same time. Further, the pressure reducing step and the step of returning to the normal pressure may be at a timing different from the step of heating. However, if the decompression step is overlapped with the heating step, the electrolytic solution can be more efficiently impregnated. The degree of decompression in the decompression step can be arbitrarily set according to the characteristics of the solvent and salt contained in the electrolytic solution to be used and other members constituting the battery. For example, the pressure can be set to 1 to 700 mmHg. More preferably, it is 1 to 400 mmHg. Furthermore, the pressure reduction rate and the time for maintaining the pressure after reaching the target pressure are not particularly limited as long as the object of the present invention can be achieved, but the former is from the viewpoint of solvent volatilization and productivity. The latter is preferably selected, and the latter may be selected from the viewpoint of electrolytic solution impregnation and productivity, and is preferably 1 minute to 20 hours.
The means for reducing the pressure inside the battery structure is not particularly limited, and examples thereof include a means for reducing the pressure using a vacuum dryer or a vacuum furnace, a means for reducing the pressure using a bell jar, a vacuum desiccator, a vacuum container, an autoclave, and the like.

In the pressure changing step, when the inside of the battery structure is pressurized, the battery structure can be uniformly impregnated with the electrolytic solution in a short time due to the pressure difference from before the pressurization. The pressure at the time of pressurization is preferably 1.1 atm or more and 10 atm or less, and more preferably 1.1 atm or more and 5 atm or less. By making the pressure range, any of the impregnation property of the electrolytic solution into the battery structure, simplification of the apparatus, and ease of operation can be further improved. In addition, when the electrolytic solution is impregnated in the battery structure by pressurization, the volatilization of the solvent contained in the electrolytic solution can be reduced. Furthermore, the battery manufacturing method of the present embodiment may further include a step of returning the battery structure to normal pressure after pressurization, and repeating the operation of pressurizing the battery structure and returning to normal pressure a plurality of times. Also good. Further, the pressurizing step and the step of returning to normal pressure may overlap with the heating step. In other words, even if pressurization is started before the end of warming after the start of warming, even if the start of pressurization is started before the end of pressurization, the warming and pressurization are started simultaneously It is possible to end the pressurization after starting the pressurization, and then end the pressurization after starting the warming (start to return to the normal pressure). Then, even if heating is finished, heating and pressurization may be finished simultaneously. Further, the pressurization step and the step of returning to the normal pressure may be at a timing different from the heating step. However, it is preferable to overlap the pressurizing step with the heating step because the electrolytic solution can be more efficiently impregnated. Furthermore, the pressurization speed and the time for maintaining the pressure after reaching the target pressure are not particularly limited as long as the object of the present invention can be achieved, but the former is preferably selected from the viewpoint of productivity, The latter may be selected from the viewpoints of electrolyte impregnation property, battery structure performance and productivity, and is preferably 1 minute to 30 hours.
The means for pressurizing the inside of the battery structure is not particularly limited, and examples thereof include a means for pressurizing using an oven or an autoclave having a pressurizing function.

Moreover, the said pressure reduction process and a pressurization process can also be used together. That is, after the battery structure is depressurized, it can be returned to normal pressure and further pressurized, and after the battery structure is pressurized, it can be returned to normal pressure and further depressurized. May be. Thereby, since a larger pressure difference can be provided, the impregnation property of the electrolytic solution into the battery structure can be further improved, and the impregnation can be sufficiently performed in a shorter time. In addition, the pressure may be reduced or increased twice or more, and the reduced pressure and the increased pressure may be alternately performed in two or more cycles.
In this way, after impregnating the electrolyte in the battery structure, if necessary, the remaining members are incorporated into the battery structure, or the battery case (exterior) is not completely sealed (sealed), or the above decompression When the sealing degree is lowered during the process such as pressurization and heating, the lithium ion secondary battery can be obtained by sealing.
Further, if necessary, after passing through the above-described steps, the shape may be adjusted, for example, by removing an excess portion of the battery structure, or the battery may be retightened or resealed.

  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 minute space in an electrochemical device structure that is normally difficult to impregnate, and thus desired device characteristics can be obtained.

  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 characteristics of the lithium ion secondary battery were measured and evaluated as follows.

(I) Evaluation of Sol-Gel Transition Temperature of Electrolytic Solution The temperature of the electrolytic solution was raised from 25 ° C., and heating of the electrolytic solution was started. Every time the temperature rose by 5 ° C., the temperature raising was stopped for 10 minutes. The temperature at which the electrolyte was completely solated while the temperature increase was stopped was measured as the sol-gel transition temperature.

(Ii) Charge / Discharge Test of Lithium Ion Secondary Battery As a lithium ion secondary battery for measurement, a single layer laminate type battery with 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.

(Preparation Example 1)
(1) Preparation of electrolytic solution Ethylene carbonate and methyl ethyl carbonate are mixed so that the volume ratio is 1: 2, and LiPF ₆ is added to the mixed solution so as to be 1 mol / L and gelled. A non-electrolytic solution (X) was prepared (hereinafter, the electrolytic solution before adding the gelling agent is referred to as “mother electrolytic 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 90 ° C. Mix evenly. The obtained mixed liquid was cooled to 25 ° C. to obtain an electrolytic solution (a), and the evaluation described in “(i) Evaluation of sol-gel transition temperature of electrolytic solution” was performed. The results are shown in Table 1.

(Preparation Example 2)
An electrolyte solution (b) was obtained in the same manner as in Preparation Example 1, except that 5 parts by mass of the compound represented by the above formula (A) as a gelling agent was added to the mother electrolyte solution (X). The electrolyte solution was evaluated as described in “(i) Evaluation of sol-gel transition temperature of electrolyte solution” above. The results are shown in Table 1.

(Preparation Examples 3 to 5)
As a gelling agent, instead of the compound represented by the above formula (A), any one of the compounds represented by the following formula (B), the following formula (C) and the following formula (D) was used. In the same manner as in Example 1, electrolytic solutions (c), (d), and (e) were obtained. The electrolyte solution was evaluated as described in “(i) Evaluation of Sol-Gel Transition Temperature of Electrolyte Solution” above. The results are shown in Table 1.

(Preparation Examples 6 and 7)
Electrolysis that is not gelled by mixing ethylene carbonate, methyl ethyl carbonate, and dimethyl carbonate in a volume ratio of 3: 3: 4, and adding LiPF ₆ to the mixture at 1 mol / L. A liquid (Y) was prepared. 3 parts by mass of the compound represented by the above formula (B) or the above formula (C) as a gelling agent is added to 100 parts by mass of the mother electrolyte (Y) with respect to the mother electrolyte (Y), Heat to 90 ° C. to mix uniformly. The obtained mixed solution was cooled to 25 ° C. to obtain electrolytic solutions (f) and (g), and the evaluation described in “(i) Evaluation of sol-gel transition temperature of electrolytic solution” was performed. The results are shown in Table 1.

(Preparation Example 8)
For the mother electrolyte (X), 3 parts by mass of the compound represented by the above formula (A) as a gelling agent with respect to 100 parts by mass of the mother electrolyte (X), and fluoroethylene carbonate (FEC) 3 parts by mass was added to 100 parts by mass of the mother electrolyte (X), and the mixture was heated to 90 ° C. and uniformly mixed. The obtained mixed liquid was cooled to 25 ° C. to obtain an electrolytic solution (h), and the evaluation described in “(i) Evaluation of sol-gel transition temperature of electrolytic solution” was performed. The results are shown in Table 1.

(Preparation Examples 9 to 11)
In the same manner as in Preparation Example 8 except that the types and amounts of the mother electrolyte, gelling agent and additive were changed as shown in Table 1, electrolytes (i), (j) and (k) were obtained, The evaluation described in “(i) Evaluation of Sol-Gel Transition Temperature of Electrolytic Solution” was performed. The 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 (a) prepared in Preparation Example 1, a laminated battery with 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. Next, an electrolyte solution (a) was injected into the cell exterior of the battery structure to 95 ° C. to form a sol (hereinafter referred to as “heating temperature”), and the laminate was made into the electrolyte solution. Soaked. Next, after temporarily sealing the remaining one side of the cell exterior, it was heated at 95 ° C. for 10 minutes using a normal pressure oven, and further cooled to 25 ° C. Next, the temporary sealing part of the cell exterior was opened, and the battery structure was pressurized to 3 atm while being heated to 95 ° C. using an oven having a pressurizing function, and held at that temperature and pressure for 2 hours ( Hereinafter, the temperature is referred to as “holding temperature”, the pressure is referred to as “pressurizing pressure”, and the time is referred to as “holding time”). Thereafter, the electrical 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 to obtain a lithium ion secondary battery (a1). About the obtained lithium ion secondary battery (a1), evaluation as described in said "(ii) Charging / discharging test of a lithium ion secondary battery" was implemented. The results are shown in Table 2.

(Examples 2-11, Comparative Examples 1-3)
Lithium ion secondary batteries (b1), (c1), (c1), (c1), (c1), (c1) and (c1), except that the electrolyte type, heating temperature, holding temperature, pressurization pressure and holding time were changed as shown in Table 2. d1), (e1), (f1), (g1), (h1), (i1), (j1), (k1), (a2), (b2) and (a3), and for those batteries, The evaluation described in “(ii) Charge / discharge test of lithium ion secondary battery” was performed. In Comparative Example 1, the battery after injecting the electrolyte into the obtained battery structure was evaluated as it was as the battery (a2) without applying pressure. The results are shown in Table 2.

(Example 12)
Using the electrolytic solution (a) prepared in Preparation Example 1, a laminated battery with 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. Next, an electrolyte solution (a) was injected into the cell exterior of the battery structure to 95 ° C. to form a sol (hereinafter referred to as “heating temperature”), and the laminate was made into the electrolyte solution. Soaked. Next, the remaining one side of the cell exterior was temporarily sealed and then heated at 95 ° C. for 10 minutes using an oven at normal pressure. Thereafter, with the battery structure containing the electrolyte maintained at 95 ° C., the battery structure was depressurized to 100 mmHg using a vacuum desiccator while the battery was sandwiched between the heating plates (this pressure is referred to as “depressurized 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 electrolyte was further depressurized to a reduced pressure, allowed to stand for 10 minutes in that state, and then returned to normal pressure. Next, the battery structure containing the electrolytic solution is cooled to 25 ° C., and unnecessary portions of the cell exterior are cut and removed, then the one side of the cell exterior is sealed, heated to 95 ° C. and heated at that temperature. It was held for 5 hours (hereinafter, the temperature here is referred to as “holding temperature” and the time is referred to as “holding time”), and further cooled to 25 ° C. to obtain a lithium ion secondary battery (a4). About the obtained lithium ion secondary battery (a4), evaluation as described in said "(ii) Charging / discharging test of a lithium ion secondary battery" was implemented. The results are shown in Table 3.

(Examples 13-22, Comparative Examples 4-6)
Batteries (b3), (c2), (d2), and (e2) in the same manner as in Example 12 except that the type of electrolytic solution, heating temperature, holding temperature, reduced pressure and holding time were changed as shown in Table 3. , (F2), (g2), (h2), (i2), (j2), (k2), (c3), (d3) and (f3). Evaluation described in “Charge / Discharge Test of Ion Secondary Battery” was performed. In Comparative Examples 4 and 5, the obtained battery structures were evaluated as batteries (c3) and (d3) as they were without reducing the pressure. Further, in Comparative Example 6, the operation for reducing the pressure and the operation for returning to the normal pressure were omitted for the obtained battery structure, and the subsequent operation for cooling the battery structure as it was was the same as in Example 12. To obtain a battery (f3). The results are shown in Table 3.

(Example 23)
Using the electrolytic solution (a) prepared in Preparation Example 1, a laminated battery with 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. Next, a gel electrolyte solution (a) at 25 ° C. was injected into the cell exterior of the battery structure. Next, after temporarily sealing the remaining one side of the cell exterior, it was heated at 90 ° C. for 10 minutes using a normal pressure oven, and further cooled to 25 ° C. Next, the battery structure containing the electrolytic solution is pressurized to 2 atmospheres while opening the temporary sealing portion of the cell exterior and heating to 90 ° C. using an oven having a pressurizing function, and the temperature and pressure are applied for 1 hour. (Hereinafter, temperature is referred to as “holding temperature”, pressure is referred to as “pressurizing pressure”, and time is referred to as “holding time”). Thereafter, the electrical 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 (a5). About the obtained lithium ion secondary battery (a5), evaluation as described in said "(ii) Charging / discharging test of a lithium ion secondary battery" was implemented. The results are shown in Table 4.

(Examples 24-33, Comparative Examples 7-9)
Lithium ion secondary batteries (b4), (c4), (d4), lithium ion secondary batteries (b4), (c4), (d4), except that the type of electrolytic solution, holding temperature, pressurizing pressure, and holding time were changed as shown in Table 4. (E3), (f4), (g3), (h3), (i3), (j3), (k3), (e4), (g4), and (h4) were obtained. The evaluation described in “ii) Charge / Discharge Test of Lithium Ion Secondary Battery” was performed. The results are shown in Table 4.

(Example 34)
Using the electrolytic solution (a) prepared in Preparation Example 1, a laminated battery with 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. Next, a gel electrolyte solution (a) was injected at 25 ° C. into the cell exterior of the battery structure. Next, the remaining one side of the cell exterior was temporarily sealed and then heated at 95 ° C. for 10 minutes using an oven at normal pressure. Thereafter, the battery structure containing the electrolytic solution was maintained at 95 ° C., and the battery structure was depressurized to 100 mmHg using a vacuum desiccator while sandwiching the battery between the heating plates (hereinafter, the temperature here is referred to as “reduced pressure”). Called heating temperature). 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. Next, while lowering the temperature to 90 ° C., the temporary seal part of the cell exterior is opened, the inside of the battery structure containing the electrolytic solution is pressurized to 2 atm using an oven having a pressurizing function, and the temperature and pressure are maintained for 1 hour. (Hereinafter, the temperature is referred to as “holding temperature” and the pressure is referred to as “pressurized pressure”). Next, 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 to obtain a lithium ion secondary battery (a6). And about the obtained lithium ion secondary battery (a6), evaluation as described in said "(ii) Charging / discharging test of a lithium ion secondary battery" was implemented. The results are shown in Table 5.

(Examples 35 to 44, Comparative Examples 10 to 12)
Batteries (b5), (c5), (d5) in the same manner as in Example 34 except that the type of electrolytic solution, heating temperature at reduced pressure, holding temperature, pressurizing pressure, and holding time were changed as shown in Table 5. , (E5), (f5), (g5), (h5), (i4), (j4), (k4), (a7), (h6) and (i5). The evaluation described in “(ii) Charge / Discharge Test of Lithium Ion Secondary Battery” was performed. In Comparative Examples 10 to 12, neither decompression nor pressurization was performed. The results are shown in Table 5.

  The method for producing an electrochemical device of this embodiment is useful when producing electrochemical devices such as solar cells, secondary batteries, capacitors, and capacitors, and is preferably a battery and a capacitor, particularly a lithium ion secondary battery. Industrial applicability as a manufacturing method.

Claims (9)

  A method of manufacturing an electrochemical device using a phase transition type gel that is gelled at 25 ° C. and becomes a sol when heated as an electrolytic solution, and changes the pressure in the electrochemical device structure into which the electrolytic solution is injected The manufacturing method of an electrochemical device including the pressure change process to make.   The method for producing an electrochemical device according to claim 1, wherein the pressure changing step includes a step of depressurizing the inside of the electrochemical device structure into which the electrolytic solution is injected.   The method for producing an electrochemical device according to claim 1, wherein the pressure changing step includes a step of pressurizing the electrochemical device structure into which the electrolytic solution has been injected.   The method for manufacturing an electrochemical device according to any one of claims 1 to 3, further comprising an injection step of injecting the electrolytic solution into the electrochemical device structure before the pressure change step.   The method for manufacturing an electrochemical device according to claim 4, wherein the electrolytic solution to be injected in the injection step is in a sol state.   The method for manufacturing an electrochemical device according to claim 4, wherein the electrolyte solution injected in the injection step is in a gel state.   The method for producing an electrochemical device according to claim 1, wherein the phase transition type gel includes a gelling agent, and the gelling agent is a low molecular weight type gelling agent.   The said phase transition type gel contains the compound which has a unsaturated bond (however, the unsaturated bond in C = O is excluded) and / or a fluorine atom, The any one of Claims 1-7. Method for manufacturing an electrochemical device.   The method for manufacturing an electrochemical device according to claim 1, wherein an exterior of the electrochemical device is made of an aluminum laminate material.