JPH11204116A - Electrochemical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently make critical electrochemical contact between a polymeric solid electrolyte and an electrode, and substantially lower an impedance with sufficient ion conductivity of the polymeric solid electrolyte by interposing an electrolyte between a solid electrode and the polymeric solid electrolyte. SOLUTION: In an electrochemical element consisting of two or more solid electrodes and a polymeric solid electrolyte between an electrode 1 and a polymeric solid electrolyte 3, an electrolyte 2 is interposed. The solid electrode 1 such as titanium that is a positive or negative electrode of this electrochemical element is preferably of irregular shape or porous body. The polymeric solid electrolyte 3 preferably consists of a compound containing oxygen, for example, a polymer such as polyethylene oxide derivative or phosphorous ester, and a solvent including an electrolytic salt is contained and formed. In the electrolyte 2, it is preferable that at least one kind of constituent component be made the same as a solvent containing the polymeric solid electrolyte, then is oozed out from the polymeric solid electrolyte 3 to be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrochemical device, and more particularly, to an electrochemical device having a solid polymer electrolyte.

[0002]

2. Description of the Related Art Electrochemical devices generally include an electrode and an ion conductor, and the ion conductor, that is, electrolyte ions, move between the electrodes as charge carriers. Things. In particular, in an electrochemical device using an electrolytic solution, the behavior of ions in the electrolytic solution is similar to the behavior of electrons and holes in a semiconductor as charge carriers. A chemical rectifier / amplifier has been proposed. Other electrochemical devices include a primary battery, a secondary battery, a capacitor, and an electrochromic display device.

[0003] Electrolyte in an electrochemical element is reliable for long-term use, such as leakage due to long-term use, drying of the inside of the element due to evaporation of a solvent, and increase in internal impedance due to skewing of the electrolyte. It had the disadvantage of lacking in properties. Therefore, recently, a solid electrochemical device in which an electrolyte is solidified (solidified) is strongly desired, and research and development are being promoted. As a result, it is possible to prevent leakage of the electrolyte and to provide a highly reliable element, and it is possible to omit measures for the electrolyte, thereby simplifying the manufacture of the element and reducing the size and size of the entire element.
Lightening is realized.

The solid electrolytes are mainly classified into inorganic solid electrolytes, organic solid electrolytes, and composite solid electrolytes. As the inorganic solid electrolyte, silver iodide, β
- _{alumina, LiI, Li 2 Ti 3,} RbAg 4 I 5, stabilized zirconia, such as CaF ₂ have been known. But,
Since the inorganic solid electrolyte has a low ionic conductivity, in order to obtain sufficient ionic conductivity, a temperature during use is required to be higher than room temperature. In some cases, molding is difficult. The moldability can be solved by forming a composite with a resin. However, in this case, there is a problem that the ion conductivity becomes unstable due to a problem such as peeling and the reliability is reduced.

[0005] Further, as the organic solid electrolyte, there is a polymer solid electrolyte, which is regarded as a promising material for improving the above-mentioned disadvantages of the inorganic solid electrolyte. The polymer solid electrolyte generally includes a polymer component serving as a matrix and an electrolyte salt serving as a carrier. Examples of the polymer component include polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene imine, polyepichlorohydrin, and polyphosphazene. Examples of the electrolyte salt include an alkali metal salt and an alkaline earth metal salt. For example, a polymer solid electrolyte made of PEO and an alkali metal salt forms a crystalline complex with PEO and an alkali metal salt, and shows high ionic conductivity. Such a polymer solid electrolyte is lightweight and flexible, and has excellent workability. On the other hand, there is a problem that the ionic conductivity is considerably lower than that using an electrolytic solution.

On the other hand, for example, an active group is introduced into the terminal of PEO or the like and crosslinked by heat or ultraviolet rays, or a high-molecular particle beam such as an electron beam or γ ray is irradiated to a linear polymer component. And cross-linking. Thus, a polymer solid electrolyte having a low glass transition temperature and an amorphous phase is obtained, and the ionic conductivity is improved.

Further, there is a method for further improving the ionic conductivity by adding a plasticizer to the crosslinked polymer solid electrolyte. Further, it has been proposed to use a polymer solid electrolyte as a thin film. However, a thin film of a micron order has a problem in the uniformity of the film thickness, and has a problem that the reliability of the obtained electrochemical element is low.

[0008] For example, Japanese Patent Application Laid-Open No. 3-53460 proposes a method using a polymer solid electrolyte in which a surfactant is added to a portion in contact with an electrode. Is being improved. However, in this case, there is a problem that the surfactant reacts on the electrode to hinder ion conduction, or the performance is deteriorated by repeated reactions.

Further, Japanese Patent Application Laid-Open Nos. 9-22736 and 9-22725 disclose a polymer solid electrolyte using a copolymer of vinylidene fluoride and hexafluoropropylene as a support for an electrolytic solution. A polymer electrolyte battery composed of a solid polymer electrolyte, a positive electrode and a negative electrode composed of an active material and an electrolytic solution has been proposed, aiming at high capacity and long life.

However, when the polymer solid electrolyte is bonded (bonded) to the solid electrode, or when the polymer solid electrolyte is cross-linked by heat or actinic rays on the electrode, a reaction occurs between the solid electrolyte and the electrode. Insufficient electrochemical contact at the interface may result in reduced interfacial area and also create high impedance problems. Especially,
These problems become remarkable when a porous electrode, an uneven electrode, or the like is used. In addition, the above-mentioned copolymer, in order to use a fluororesin, when a polar solvent is used as the electrolytic solution,
There is a problem that the compatibility with the polar solvent is poor, and the ionic conductivity of the solid polymer electrolyte is low.

The present invention has been made in view of the above-mentioned problems, and is an electrochemical device using a polymer solid electrolyte, which is capable of sufficiently contacting a polymer solid electrolyte with an electrode, It is an object of the present invention to provide an electrochemical device capable of sufficiently obtaining the ionic conductivity of the electrochemical device.

[0012]

According to the present invention, there is provided an electrochemical device comprising two or more solid electrodes and a solid polymer electrolyte, wherein an electrolyte is interposed between the solid electrode and the solid polymer electrolyte. Provided.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The electrochemical device of the present invention is formed by laminating two or more solid electrodes and a solid polymer electrolyte, and an electrolyte is interposed between the solid electrodes and the solid polymer electrolyte. In the present invention, the solid electrode is not particularly limited as long as it is a solid conductor generally used as a positive electrode or a negative electrode of an electrochemical element. The solid conductor may be any of a simple substance, a compound, an alloy, a composite, a mixture, and a molded body, and may be a single layer or two or more layers.
Further, it may be any of a flat plate shape, an uneven shape, and a porous shape. Above all, an uneven shape and a porous shape are preferable. Also,
Each solid electrode may be the same material or different materials. The thickness, size, and the like thereof can be appropriately adjusted depending on the material used, the intended function of the electrochemical element, and the like.

As the simple substance, for example, titanium, aluminum, copper, silver, zinc, gold, platinum, lithium, sodium, potassium, calcium, barium, magnesium,
Vanadium, manganese, iron, cobalt, nickel, silicon, carbon, zirconium, niobium, molybdenum, palladium, indium, cadmium, tin, tungsten,
Examples include metals such as lead.

Compounds and alloys include SnO ₂ , IT
O, transparent conductive oxides such as titanium oxide; iron oxide, nickel oxide, cobalt oxide, tungsten oxide, molybdenum oxide, titanium sulfide, molybdenum sulfide, titanium selenide,
Chalcogen compounds such as niobium selenide; nitrides such as iron nitride and manganese nitride; carbides such as iron carbide, silicon carbide, tungsten carbide and molybdenum carbide; conductive polymers such as polyaniline, polythiophene, polypyrrole and polyacetylene; Alloys, stainless steels, and the like.

Examples of the composite include those in which the above-mentioned metal is modified with an organic molecule, those in which a metal is supported on an oxide, those in which an oxide is deposited on a metal, and the like. Examples of the organic molecules include crown ethers, porphyrins, conductive polymers, dyes such as indigo, proteins, and the like. Examples of the mixture include a mixture in which powder is used as an electrode active material, and one or more powdered conductive materials are arbitrarily mixed with a binder. Specific examples include, but are not limited to, carbons such as carbon black, acetylene black, and Ketjen black, graphite powder (natural graphite, artificial graphite), metal powder, metal fiber, and conductor oxide. Not something. As the binder, polytetrafluoroethylene, fluorine-based polymer such as polyvinylidene fluoride, polyethylene, polypropylene, polyolefin-based polymer such as ethylene-propylene-diene terpolymer, styrene-butadiene rubber, ABS resin, polyurethane resin, polyacrylonitrile, Epoxy resin, polyvinyl chloride, polystyrene, silicone resin,
Examples include a polyimide resin, a polyvinyl alcohol resin, a methacrylic resin, a natural rubber, cellulose, a phenol resin and the like. Further, in order to further improve ionic conductivity, a solid polymer electrolyte shown below may be used.

Examples of the molded article include a molded article obtained by molding the above-mentioned mixture into a desired shape, an article obtained by coating a conductor such as a metal on an oxide, or a simple substance, a compound, an alloy, a composite, or a mixture. Examples thereof include those in which a current collector is laminated on an electrode, those in which an oxide is deposited on a current collector, and the like. As the current collector, a metal simple substance, an alloy, carbon, a transparent electrode (tin oxide, ITO, titanium oxide, or the like), a conductive oxide sintered body, or the like is used. For example, there are titanium, aluminum, stainless steel and the like. Further, those obtained by treating the surface of copper, aluminum, or stainless steel with carbon, titanium, silver, or the like, or those obtained by oxidizing the surface of these materials are also used. The shape of the current collector is foil, film, sheet, net, punched, lath,
It may be a porous body, a foamed body, a molded body of a fiber group, or the like.

In the present invention, the solid polymer electrolyte comprises:
An electrolyte salt optionally containing a solvent and a polymer component that dissociates the electrolyte salt, or a polymer component optionally containing an ion-dissociating group containing a solvent, an electrolyte salt, a solvent and polyacrylonitrile, a polyethylene oxide derivative, and derivatives thereof , A polypropylene oxide derivative, a polymer containing this derivative or a phosphate polymer.

The thickness of the polymer solid electrolyte varies depending on the size, type and function of the electrochemical element to be obtained.
In order to obtain appropriate mechanical strength and ionic conductivity, 1μ
It is preferably about m to 10 mm. As an electrolyte salt constituting the polymer solid electrolyte, for example, lithium perchlorate (L
iClO _4), lithium borofluoride (LiBF _4), Rinfu' lithium (LiPF _{6), 6} fluoride arsenate lithium (LiAsF _{6), 6} lithium fluoride antimonate (L
iSbF ₆ ), lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ), lithium trifluoroacetate (LiC
F ₃ COO), lithium halide, lithium salts such as lithium chloride aluminate (LiAlCl _4), sodium perchlorate (NaClO _4), sodium borofluoride (N
aBF ₄ ), sodium thiocyanate (NaSCN),
Sodium halide, potassium borofluoride (KB
F ₄ ), magnesium perchlorate (Mg (ClO ₄ ) ₂ ),
Magnesium borofluoride (Mg (BF ₄ ) ₂ ), tetraalkylammonium perchlorate (R ₄ NClO ₄ : R is a linear or branched alkyl group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms) For example, methyl, ethyl, propyl,
Isobutyl, t-butyl and the like), tetrafluoroalkylammonium borofluoride (R ₄ NBF ₄ : R is as defined above) and the like. The content of the electrolyte salt depends on the composition of the polymer solid electrolyte, but is preferably 0.001 mol to 5 mol, more preferably 1 mol ³ to 1 dm ^{3 of the} polymer solid electrolyte in order to obtain sufficient ionic conductivity. It is 0.01 mol to 3 mol. As described later, when the solid polymer electrolyte contains a solvent, the amount of the electrolyte salt depends on the type of the solvent to be combined and the type of the electrolyte salt. 0.01 mol to 7 per liter
Mol, preferably 0.1 mol to 5 mol.

The solvent optionally contained in the solid polymer electrolyte is, for example, about 0 to 90% by weight, more preferably about 20 to 90% by weight. Examples of the solvent include the solvents described below, and a polar solvent is particularly preferable. The polymer component that dissociates the electrolyte salt that constitutes the polymer solid electrolyte is not particularly limited as long as it is a polymer component that usually constitutes the polymer solid electrolyte of the electrochemical element. Actinic rays (light, ultraviolet, electron beam,
(γ-rays, X-rays, etc.).

The polymer component obtained by thermal polymerization includes a polymer component obtained by a urethane reaction, a reaction of a polymerization compound having an epoxy group or an acrylate group, or the like.
For example, a polymer component obtained by a reaction between a polyol and an isocyanate which is a polymerization initiator, or a reaction between a lactone and / or a carbonate and an isocyanate which is a polymerization initiator may be mentioned.

As the polyol which is a compound for polymerization,
A polymer component having two or more hydroxy groups;
For example, acrylic polyol, polyether polyol, polyester polyol, polysiloxane polyol, terminal amine polyol, halogen-containing polyol,
Polybutadiene polyol partially saponified ethylene-vinyl acetate copolymer, phenolic polyol phosphorus-containing polyol,
Examples include polyoxyalkylene polyols formed by polymerizing alkylene oxides (ethylene oxide, propylene oxide, tetrahydrofuran, etc.). Above all, acrylics, polyether polyols and polyester polyols are preferable from the viewpoint of availability. These have a molecular weight of 100 in consideration of mechanical strength.
The thing of 0-100,000 is preferable. These may be used alone or in combination of two or more. The oxyalkylene group in the polyoxyalkylene polyol may be used alone or in combination of two or more. In particular, a polyoxyalkylene polyol obtained by copolymerizing ethylene oxide and propylene oxide is preferable.

When a polyol is used, it is preferable to use a crosslinking agent in combination from the viewpoint of improving ionic conductivity. Examples of the crosslinking agent include polyhydric alcohols, polyamines, alkanolamines, and water. Among them, ethylene glycol, propylene glycol, 1,4-butanediol, trimethylolpropane, 3,3′-dichloro-4,4′-diaminodiphenylmethane, and triethanolamine are preferable, and polyhydric alcohols are particularly preferable.

The isocyanate which is a polymerization initiator is preferably a polyisocyanate. Specifically, tolylene diisocyanate, dibiphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, toluidine diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, 4,4′-metaphenylene diisocyanate, isoboron diisocyanate, xylene diisocyanate and their prepolymers Polymers. Isocyanates have a content of NCO groups in the compound of 50% in consideration of ion conductivity.
(% By weight) or less, more preferably about 40% or less. This is because when the NCO group content exceeds 50%, the ionic conductivity becomes poor.

Examples of the lactones and carbonates which are polymerization compounds include γ-butyrolactone, γ-valerolactone, δ-valerolactone, ε-caprolactam,
Examples thereof include propylene carbonate, ethylene carbonate, styrene carbonate, and butylene carbonate, such as methyl-1,3-oxazolidin-2-one and 3-ethyl-1,3-oxazolidine-2-one. These lactones and carbonates may be used in combination. Of these, a combination of γ-butyrolactone or ε-caprolactam with ethylene carbonate or propylene carbonate is preferred.

The polymer component formed by using the above-mentioned compound for polymerization includes polyurethane, epoxy polymer,
Polyacrylate, polycarbonate, polyester,
Polyamide and the like can be mentioned. Above all, the polymer component constituting the polymer solid electrolyte in the present invention is a polymer of an oxygen-containing compound (for example, a polyethylene oxide derivative, a polymer containing this derivative, a polypropylene oxide derivative, a polymer containing this derivative, a phosphate ester) Particularly preferred is a polymer.

The polymer component obtained by the actinic ray polymerization reaction includes a polymerizable compound obtained by a polymerization reaction with an unsaturated carboxylic acid ester, a polyene / polythiol mixture and a crosslinkable macromer (organosilane, polyisothianaphthene, etc.). Polymer component. As the unsaturated carboxylic acid ester which is a compound for polymerization,
Acrylates (acrylates, methacrylates, etc.)
Is mentioned. In addition, the acrylates include monofunctional and polyfunctional acrylates.

Monofunctional acrylates include alkyl acrylates (methyl acrylate, butyl acrylate, trifluoroethyl acrylate, etc.), alkyl methacrylates (methyl methacrylate, butyl methacrylate, trifluoroethyl methacrylate, etc.), tetrahydrofurfuryl acrylate , Tetrahydrofurfuryl methacrylate, etc., hydroxyalkyl acrylate (hydroxyethyl acrylate, hydroxypropyl acrylate, etc.), hydroxyalkyl methacrylate, hydroxypolyoxyalkylene acrylate (hydroxypolyoxyethylene acrylate, hydroxypolyoxypropylene acrylate, etc.), hydroxypolyoxy Alkylene methacrylate (hydroxypolyoxy Ethylene methacrylate,
Hydroxypolyoxypropylene methacrylate, etc.)
And alkoxyalkyl acrylates (such as methoxyethyl acrylate and ethoxyethyl acrylate), phenoxyalkyl acrylates (such as phenoxymethyl acrylate and phenoxyethyl acrylate), and alkoxy methacrylate.

Examples of polyfunctional acrylates include trimethylolpropane triacrylate, pentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, trimethylolpropane trimethacrylate, pentaerythritol pentamethacrylate, and dipentaerythritol hexaacrylate. . Furthermore, alkyl alkylene glycol acrylate (methyl ethylene glycol acrylate, ethyl ethylene glycol acrylate, propyl ethylene glycol acrylate, phenyl ethylene glycol acrylate, ethyl propylene glycol acrylate, butyl propylene glycol acrylate, etc.),
Furfuryl ethylene glycol acrylate, tetrahydrofurfuryl ethylene glycol acrylate, furfuryl propylene glycol acrylate, tetrahydrofurfuryl propylene glycol acrylate and the like can be mentioned. These acrylates usually have a molecular weight of 50
Although it is less than 100,000, acrylates having a molecular weight of about 300 to 1,000,000 are easy to control leaching of the solvent in a polymer solid electrolyte containing a solvent described below.
preferable.

In order to improve the mechanical strength, the unsaturated carboxylic acid ester can be further used by mixing a polyfunctional unsaturated carboxylic acid ester. As the polyfunctional unsaturated carboxylic acid ester, those having two or more acryloyl groups or methacryloyl groups are preferable. Specifically, diethylene glycol diacrylate, butanediol diacrylate, trimethylolpropane triacrylate, dipentaerythritol hexaacrylate , Diethylene glycol dimethacrylate, butanediol dimethacrylate, trimethylolpropane trimethacrylate, dipentaerythritol hexamethacrylate and the like.

The unsaturated carboxylic acid ester is
A photopolymerization initiator can be used in combination. As the photopolymerization initiator, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether,
Benzoins such as benzoin isobutyl ether, α-methylbenzoin, α-phenylbenzoin, anthraquinones, methylanthraquinone, anthraquinones such as chloranthraquinone, benzyl, diacetyl, acetophenone, benzophenone, methylbenzoylformate, diphenylsulfide, dithiocarbamate,
α-Chloromethylnaphthalene, acrylic flavin, fluorescein, iron chloride, silver chloride, p-methoxybenzenediazonium, hexafluorophosphate, diphenyliodonium, triphenylsulfonium and the like.

The polymer component formed by polymerization of the above-mentioned compounds includes polyurethane, polyacrylate, polyester and the like. As the polymer component having an ion dissociating group, -NR ₃ ⁺ group in the main chain or side chain of the polymer component,
-SO ₃ ^- group, -COO ^- polymer component such as cationic group or an anionic group such as a group is bond.

The solvent which may optionally be contained in the solid polymer electrolyte is preferably contained from the viewpoint of ionic conductivity at room temperature. For example, water, an ether solvent (methylal, 1,2-dimethoxyethane, 1-
Ethoxy-2-methoxyethane, 1,2-diethoxyethane, dioxolan, diethyl ether, etc., ester solvents (methyl formate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, etc.), lactone solvents (γ-butyrolactone) , Γ-valerolactone, δ-valerolactone, 3-methyl-1,3-oxazolidine-2
-One, 3-ethyl-1,3-oxazolidine-2-one, etc.), carbonate solvents (propylene carbonate,
Ethylene carbonate, butylene carbonate, styrene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, etc., nitrile solvent (acetonitrile, 3-methoxypropionitrile, etc.), furan solvent (tetrahydrofuran, 2-methyltetrahydrofuran, 2,5- Dimethoxytetrahydrofuran, etc.), imidazolidinone solvent (1,3-dimethyl-
2-amidazolidinone, amide solvents (N-methylformamide, N, N-dimethylformamide, N-methylacetamide, N-methylpyrrolidinone, etc.), alcohol solvents (methanol, ethanol, ethylene glycol, propylene glycol, Diethylene glycol,
1,4-butanediol, glycerin, polyethylene oxide, polypropylene oxide, etc.), pyrrolidone (N
-Methyl-2-pyrrolidone, etc.) and other solvents (dimethylsulfoxide, sulfolane, methylsulfolane, etc.). These solvents can be used alone or as a mixed solvent of two or more. Above all, water, N
-Methylformamide, N, N-dimethylformamide, N-methylacetamide, N-methylpyrrolidinone, methanol, ethanol, ethylene glycol, propylene glycol, diethylene glycol, 1,4-
Butanediol, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, γ-butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran, dioxolane, diethyl ether, dimethoxyethane, diethoxyethane, methoxyethoxyethane, dimethyl Sulfoxide, sulfolane,
Preferred are methylsulfolane, acetonitrile, 3-methoxypropionitrile, methyl formate, methyl acetate, pyrrolidone and the like.

In the present invention, as the electrolytic solution interposed between the solid electrode and the solid polymer electrolyte, a solution in which the above-mentioned electrolyte salt is dissolved in the above-mentioned solvent can be used. Specifically, water, N-methylformamide, N, N
-Dimethylformamide, N-methylacetamide, N
-Methylpyrrolidinone, methanol, ethanol, ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, γ-butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran, dioxolane, diethylether, dimethoxyethane, diethoxyethane, methoxyethoxyethane, dimethylsulfoxide, sulfolane, methylsulfolane, acetonitrile, 3-methoxypropionitrile, methyl formate, methyl acetate, methyl acetate, pyrrolidone, etc., and an electrolyte salt As lithium perchlorate (LiClO ₄ ), lithium borofluoride (Li
BF ₄ ), lithium phosphofluoride (LiPF ₆ ), lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ), lithium trifluoroacetate (LiCF ₃ COO), lithium halide, lithium aluminate (LiAlC)
l ₄ ), sodium perchlorate (NaClO ₄ ), sodium borofluoride (NaBF ₄ ), sodium thiocyanate (NaSCN), sodium halide, potassium borofluoride (KBF ₄ ), magnesium perchlorate (Mg (C
10 ₄ ) ₂ ), magnesium borofluoride (Mg (BF ₄ )
₂ ), tetraalkylammonium perchlorate (R ₄ NC
lO ₄ ), tetraalkylammonium borofluoride (R
₄ NBF ₄ ).

In the present invention, the solid polymer electrolyte is
It can be produced by a usual method as described below. A method of dissolving and mixing an electrolyte salt and a polymer component in a volatile solvent, forming the mixture, removing the volatile solvent, dissolving and mixing the electrolyte salt and the compound for polymerization in the volatile solvent, After forming the mixture, polymerize with heat or actinic light to remove volatile solvents, dissolve and mix the electrolyte salt and the compound for polymerization in a solvent, mold these mixtures, and polymerize with heat or actinic light Method of dissolving the electrolyte salt and polymer component in a solvent by increasing the temperature
Mixing, molding these mixtures and then lowering the temperature.

Among the above methods, the above method is a method for producing a solid polymer electrolyte without a solvent, and the second method is a method for producing a solid polymer electrolyte containing a solvent. In the present invention, the electrochemical device can be manufactured by the following method. (i) A method in which an electrode and a solid polymer electrolyte are individually formed, these are bonded, and an electrolytic solution is impregnated into the bonded element. (ii) a method of laminating an electrode impregnated with or wetted with an electrolyte and a polymer solid electrolyte, (iii) a method of laminating an electrode with a polymer solid electrolyte wetted with an electrolyte, and (iv)
A method of laminating an electrode with a polymer solid electrolyte contained to the extent that the electrolyte oozes out, (v) a method of combining (ii) and (iii), and (vi) a method of (ii) and (iv). (Vii) A method of directly producing a solid polymer electrolyte containing an electrolyte to the extent that it oozes out on the electrode.

Among the above methods, the production methods (iv) and (vii) are preferred from the viewpoint of simplicity of the process and ion conductivity.
In particular, by superposing two or more solid electrodes and a polymer solid electrolyte capable of oozing out the electrolyte, and then pressing the superposed element, it is possible to control the electrolyte oozing out of the polymer solid electrolyte. Therefore, it is more preferable. In the present invention, when the electrolyte oozes out of the polymer solid electrolyte, it means that a solvent or an electrolyte from the produced polymer solid electrolyte, for example, a phenomenon in which the liquid moves to the tissue when the tissue is in contact with the tissue can be confirmed. I do.

[0038]

EXAMPLES Examples of the electrochemical device of the present invention will be specifically described below, but the present invention is not limited to these.

Example 1 First, polyethylene oxide (average molecular weight: 5,000,000)
And sodium perchlorate (NaClO ₄ ) in a weight ratio of 1
The solution was dissolved in acetonitrile at a ratio of 1: 1 and the solution was cast on a glass substrate, and the acetonitrile was dried and removed at a temperature of 80 ° C. or higher to prepare a solid polymer electrolyte A having a size of about 0.5 mm. In this polymer solid electrolyte A, 0.1 mol /
dm ³ of sodium perchlorate.

Next, as shown in FIG. 1, the polymer solid electrolyte A was sandwiched between electrodes (5 cm ² ) made of a nickel plate. A few drops of propylene carbonate electrolyte in which 1 mol / l of sodium perchlorate was dissolved was dropped between the solid polymer electrolyte A and the electrode (both interfaces) in this holding body, and FIG. (Shown only) was manufactured.

The holding body was immersed in the same electrolytic solution for one minute to produce an electrochemical device A2 having a similar structure. Further, both surfaces of the polymer solid electrolyte A are wetted with the same electrolytic solution as above, and sandwiched between the same electrodes as above,
An electrochemical device A3 having the same configuration was manufactured. Further, several drops of the same electrolytic solution as above were dropped on the same electrode as above, and this was laminated on both surfaces of the solid polymer electrolyte A to produce an electrochemical device A4 having the same configuration.

Using the electrochemical devices A1 to A4 obtained above, the impedance at 50 KHz was measured at 30 ° C. by the alternating current method. As a result, the electrochemical device A1
Was 244Ω, A2 was 210Ω, A3 was 224Ω, and A4 was 231Ω.

Comparative Example 1 An electrochemical device a5 as shown in FIG. 1 was manufactured in the same manner as in Example 1 using the solid polymer electrolyte prepared in Example 1. This electrochemical element a5 has a structure in which no electrolytic solution is interposed between the solid electrolyte and the electrode.

Example 1 using this electrochemical element a5
When the impedance at 50 KHz was measured by the alternating current method in the same manner as in the above, it was 13.4 kΩ.

Example 2 First, a copolymer of vinylidene fluoride and hexafluoropropylene and sodium perchlorate were dissolved in acetone as a fluoropolymer solid electrolyte, and this solution was cast on a glass substrate. Dry and remove at room temperature,
A polymer solid electrolyte B of about 0.5 mm was produced. This polymer solid electrolyte B contains 0.01 mol / dm ³ of sodium perchlorate.

Next, as shown in FIG. 1, the solid polymer electrolyte B was sandwiched between electrodes made of a nickel plate similar to that used in Example 1. A few drops of the same electrolytic solution as used in Example 1 were dropped between the solid polymer electrolyte B and the electrode (both interfaces) in this holding body, and the electrochemical solution as shown in FIG. Element B1 was manufactured. Further, the sandwiched body was immersed in the same electrolytic solution as above for 3 minutes to produce an electrochemical device B2 having the same configuration.

Further, both surfaces of the solid polymer electrolyte B were wetted with the same electrolytic solution as described above, and were sandwiched between the same electrodes as above, thereby producing an electrochemical device B3 having the same structure. Also,
A few drops of the same electrolytic solution were dropped on the same electrode as above, and this was laminated on both surfaces of the solid polymer electrolyte B to produce an electrochemical device B4 having the same configuration. Using the electrochemical devices B1 to B4 obtained above, the impedance at 50 KHz was measured at 30 ° C. by an alternating current method.

As a result, the electrochemical element B1 was 2.3K.
Ω, B2 is 466Ω, B3 is 1.8KΩ, B4 is 3.4
KΩ.

Comparative Example 2 An electrochemical device b5 as shown in FIG. 1 was produced in the same manner as in Example 1 using the solid polymer electrolyte produced in Example 2. This electrochemical element b5 has a structure in which no electrolytic solution is interposed between the solid electrolyte and the electrode.

Using the electrochemical device b5, Example 1
When the impedance at 50 KHz was measured by the AC method in the same manner as in the above, it was 39.4 KΩ. As is clear from the above Examples 1 and 2 and Comparative Examples 1 and 2, by providing an electrolytic solution between the solid electrode and the solid polymer electrolyte, sufficient electrochemical contact can be obtained, An improvement in impedance was observed. In addition, even when a copolymer of vinylidene fluoride and hexafluoropropylene as a fluorine-based polymer solid electrolyte is used, by interposing the electrolyte, the polymer solid electrolyte can be sufficiently contacted with the electrode. And the impedance was improved.

Example 3 An electrochemical device having an interface structure between an electrode and a solid polymer electrolyte shown in FIG. 3 was produced by the following method. As shown in FIG. 1, the polymer solid electrolyte A prepared in Example 1 was polished with polishing paper (cc-120-cw) to a nickel plate electrode (5).
cm ² , uneven electrode). This was immersed in the same electrolytic solution as in Example 1 for 1 minute to produce an electrochemical element A6. About this electrochemical element A6, as a result of measuring the impedance similarly to Example 1, it was 201 ohm.

Comparative Example 3 Using the polymer solid electrolyte A prepared in Example 1, an electrochemical device a7 as shown in FIG.
Was manufactured. The electrochemical element a7 has a structure in which no electrolytic solution is interposed between the solid electrolyte and the electrode.

Using this electrochemical element a7, Example 1
When the impedance at 50 KHz was measured by the alternating current method in the same manner as in the above, it was 182 kΩ. From the above Examples 1 and 3 and Comparative Examples 1 and 3, the use of the uneven electrode
As compared with the flat electrode, the presence of the electrolytic solution between the electrode and the solid polymer electrolyte significantly reduced the impedance, and markedly improved the electrochemical contact.

Example 4 First, ethoxy polyethylene glycol acrylate (average molecular weight: 1000) and propylene carbonate in which 1 mol / l of lithium perchlorate (LiClO ₄ ) was mixed at a weight ratio of 30:70, To this, methylbenzoyl formate as a photopolymerization initiator was added in an amount of about 5% by weight based on ethoxypolyethylene glycol acrylate, and this liquid was cast on a glass substrate. Containing solid polymer electrolyte C was prepared. It was confirmed that when a tissue was placed on the polymer solid electrolyte C, the liquid began to seep out. The oozing of the liquid makes it possible for the electrolyte to intervene between the electrode and the solid electrolyte. The polymer solid electrolyte C contains 0.7 mol / dm ³ of lithium perchlorate.

Next, a lithium metal foil was used as the first electrode,
As shown in FIG. 2, the polymer solid electrolyte C was laminated on one surface. Further, as the second electrode, LiCoO which is a conductive material is used.
_2. 100 parts each of acetylene black as a powder electrode material and polytetrafluoroethylene as a binder
After mixing in a mortar at a ratio of 10:10, aluminum foil was used as a current collector, and these were pressed and formed, and as shown in FIG. By stacking, the electrochemical device C1 was manufactured.

Further, the electrochemical device C2 was manufactured by applying pressure to the electrochemical device C1 with a vice. After electrolyzing these electrochemical devices C1 and C2 at a constant voltage of 3.9 V for 3 hours, Example 1 was applied while applying a voltage of 3.9 V.
The impedance was measured as described above. As a result, 50K
As for the resistance at Hz, C1 was 152Ω and C2 was 121Ω.

Further, when the change in impedance due to the frequency change from 100 KHz to 100 mHz was measured, there was a response regarding charge transfer, and apparent charge transfer resistances were 105 Ω and 80 Ω, respectively.

Comparative Example 4 First, 70 parts by weight of ethoxy polyethylene glycol acrylate (average molecular weight: 1000), 2.5 mol / l
Mixed electrolyte of propylene carbonate and acetonitrile in which lithium perchlorate (LiClO ₄ ) is dissolved (1:
4) Mix at 30 parts by weight, add about 5% by weight of methylbenzoylformate as a photopolymerization initiator to ethoxypolyethylene glycol acrylate, cast the liquid on a glass substrate, and apply a high pressure mercury lamp. , And acetonitrile was removed by drying at 80 ° C. or higher to prepare a solvent-containing polymer solid electrolyte d of about 0.5 mm. No bleeding of the liquid was observed even when a tissue was placed on the polymer solid electrolyte. The polymer solid electrolyte d contains 0.7 mol / dm ³ of lithium perchlorate.

As the first electrode and the second electrode, the same type of electrodes as used in Example 3 were used. First electrode, solid polymer electrolyte d
And the second electrode were stacked to produce an electrochemical device d1. Furthermore, the electrochemical element d2 was manufactured by applying a pressure to the electrochemical element d1 with a vice. These elements were electrolyzed at a constant voltage of 3.9 V for 3 hours as in Example 3, and then the impedance was measured as in Example 1 while applying a voltage of 3.9 V. As a result, 50KH
The resistance at z is 4.8 KΩ for d1 and 3.3 KΩ for d2.
Met.

Further, when the change in impedance due to the frequency change from 100 KHz to 100 mHz was observed, there was a response related to charge transfer, and apparent charge transfer resistances were 1.1 KΩ and 892 Ω, respectively. Compared to Examples 1 and 4 and Comparative Examples 1 and 4, the impedance was significantly reduced when the porous electrode was used, because the electrolyte was interposed between the electrode and the solid polymer electrolyte, compared to the flat electrode. , There was a significant improvement in electrochemical contact.

Example 5 First, ethoxy polyethylene glycol acrylate (average molecular weight: 1000) and propylene carbonate in which 1 mol / l of lithium perchlorate (LiClO ₄ ) was dissolved were mixed at a weight ratio of 30:70. In Example 3, a mixture obtained by adding methylbenzoylformate as a photopolymerization initiator thereto (similar to Example 3 so that the electrolyte solution can be exuded after the preparation of the solid polymer electrolyte) is obtained. Cast on the used second electrode (porous electrode)
An actinic light from a high-pressure mercury lamp was used to produce a solid polymer electrolyte containing a solvent of about 0.5 mm to produce an electrochemical device as shown in FIG. In addition, as shown in FIG. 2, the other surface of the solid electrolyte was formed by laminating the first electrode used in Example 3 to manufacture an electrochemical device C3.

This device was treated with 3.9 V in the same manner as in Example 3.
After performing electrolysis at a constant voltage of 3 hours and applying a voltage of 3.9 V, the impedance was measured in the same manner as in Example 1. As a result, the resistance at 50 KHz was 115Ω. Further, when the change in impedance due to the frequency change from 100 KHz to 100 mHz was observed, there was a response related to the charge transfer.
Ω.

Comparative Example 5 Ethoxy polyethylene glycol acrylate (average molecular weight: 1000) was mixed with a mixed electrolyte of propylene carbonate and acetonitrile in which 2.5 mol / l of lithium perchlorate (LiClO ₄ ) was dissolved. The second electrode used in Example 3 was obtained by adding methylbenzoylformate as a photopolymerization initiator (the same as in Comparative Example 4, so that the electrolyte solution after the production of the solid polymer electrolyte did not exude). (Porous body electrode), polymerized with actinic light from a high-pressure mercury lamp, and acetonitrile was dried and removed at a temperature of 80 ° C. or more to prepare a polymer solid electrolyte containing about 0.5 mm of a solvent. The electrochemical device d3 was manufactured by superimposing the first electrodes used in No.3.

This device was treated with 3.9 V in the same manner as in Example 3.
, And the impedance was measured in the same manner as in Example 1 while applying a voltage of 3.9 V. As a result, the resistance at 50 KHz was 795Ω. Further, when the change in the impedance due to the frequency change from 100 KHz to 100 mHz was observed, there was a response related to the charge transfer, and the apparent charge transfer resistance was 614Ω respectively.

From Examples 4 and 5 and Comparative Examples 4 and 5, the electrolyte oozes out of the solid polymer electrolyte and intervenes between the electrodes, thereby improving not only the electrochemical contact but also the charge transfer resistance. And the improvement of the performance as an electrochemical element was recognized.

Example 6 As shown in FIG. 5, a transparent electrode was formed by depositing ITO on a transparent glass substrate as a first electrode, and a polyaniline was deposited on the first transparent electrode by electrolytic polymerization as a second electrode. used.

First, ethoxy polyethylene glycol acrylate (average molecular weight: 1000) and propylene carbonate in which 1 mol / l of lithium perchlorate (LiClO ₄ ) was dissolved were mixed at a weight ratio of 30:70.
A mixture obtained by adding methylbenzoyl formate as a photopolymerization initiator thereto (similar to Example 3, so that the electrolyte solution can ooze out after the preparation of the solid polymer electrolyte).
Is cast on the above-mentioned second electrode, an active ray from a high-pressure mercury lamp is used to produce a polymer-containing solid electrolyte containing a solvent, and the above-mentioned first electrode is laminated to form an electrochemical element, in this case, an electrochromic element. Was manufactured.

When a voltage of 2 V was applied to this element,
Coloring took about 0.8 seconds. Thereafter, when a voltage of -0.3 V was applied, the color was erased.

Comparative Example 6 Ethoxypolyethylene glycol acrylate (average molecular weight: 1000) and a mixed electrolyte of propylene carbonate and acetonitrile in which 2.5 mol / l of lithium perchlorate (LiClO ₄ ) were dissolved were mixed. On the second electrode used in Example 4 was added one in which methylbenzoylformate was added as a polymerization initiator (the same as in Comparative Example 4, so there was no seeping out of the electrolytic solution after the preparation of the solid polymer electrolyte). And polymerized with actinic light from a high-pressure mercury lamp, and acetonitrile was dried and removed at a temperature of 80 ° C. or more to produce a polymer-containing solid electrolyte containing a solvent. Further, the first electrode used in Example 4 was overlaid. To produce an electrochemical device, in this case, an electrochromic device.

When a voltage of 2 V was applied to this element,
Coloring took about 1.7 seconds. Thereafter, when a voltage of -0.3 V was applied, the color was erased. From Example 6 and Comparative Example 6,
It can be seen that the adoption of the electrochemical device structure in the present invention increases the coloring speed of the electrochromic device and improves the performance.

Example 7 and Comparative Example 7 In Example 5 and Comparative Example 5, a constant voltage of 3.9 V
When the current value after 3 hours of the electrolysis for 1 hour was measured, they were 1 μA and 13 μA, respectively.

From Example 7 and Comparative Example 7, it can be seen that the adoption of the electrochemical element structure according to the present invention improves the electrolysis speed, that is, responds faster and improves the performance. In addition, in an element that stores an amount of electricity, it is possible to store the element more compactly and more quickly, and in an element that performs a reaction, it is possible to perform more reactions in a shorter time, and furthermore, the impedance is further reduced. By being small, an element with less energy loss is possible.

Example 8 The electrochemical device C1 produced in Example 4 was evaluated as follows. This element was electrolyzed at a constant voltage of 3.9 V for 3 hours, and then electrolyzed at a constant voltage of 2.8 V for 3 hours. These operations were repeated 100 times, and then the impedance was measured in the same manner as in Example 1 while applying a voltage of 3.9 V. As a result, the resistance at 50 KHz was 198Ω.

Comparative Example 8 The solid polymer electrolyte d prepared in Comparative Example 4 was immersed in a sodium dodecylbenzenesulfonate solution as a surfactant, and the same first and second electrodes as used in Example 3 were used. Was used, and a first electrode, a solid polymer electrolyte d, and a second electrode were stacked in this order to manufacture an electrochemical device d3. This was evaluated by the method described in Example 1. As a result, the resistance at 50 kHz was 186Ω.

Further, as a result of evaluation by the method of repeating operation 100 times described in Example 8, the resistance at 50 kHz was 5.9 kΩ. Example 8 and Comparative Example 8
This indicates that when a surfactant is present at the interface between the electrode and the solid electrolyte, deterioration due to repetition is more severe than in the case of the present invention. This is thought to be because the surfactant reacts on the electrode.

Comparative Example 9 Using the electrochemical device d1 produced in Comparative Example 4, Example 8
As a result of the evaluation by the method of 100 repetition operations described in the above section, the resistance at 50 kHz was 13. It was 2 kΩ. From the results of Examples 4 and 8 and Comparative Examples 4 and 9, it was found that the electrochemical element in which the electrolytic solution was interposed between the solid electrode and the polymer solid electrolyte had a small increase in impedance due to repetition and was strong against repetition. This is considered to be due to the improved electrochemical contact at the interface between the solid polymer electrolyte where the reaction occurs and the electrode.

[0077]

According to the present invention, since the electrolyte is interposed between the solid electrode and the polymer solid electrolyte, the reaction due to the electrochemical contact between the solid electrolyte and the solid electrode in the solid electrochemical device is suppressed. However, the charge transfer resistance corresponding to such a reaction can be reduced, and the impedance can be significantly reduced.

In particular, when a porous electrode, a concavo-convex electrode, or the like is used as the solid electrode, the compatibility with a polar solvent is improved, the ionic conductivity is improved, and the above effect is large. Also,
In an element that stores an amount of electricity as an electrochemical element in the present invention, it is smaller and can store more quickly, and in an element that performs a reaction, it is possible to perform more reactions in a shorter time. In addition, since the impedance can be significantly reduced, an electrochemical element with less energy loss can be provided.

Furthermore, since the electrochemical contact at the interface between the electrode and the solid polymer electrolyte where the reaction occurs is improved, it is possible to provide an electrochemical element that is strong against repetition.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a basic structure of an electrochemical device of the present invention.

FIG. 2 is a schematic sectional view showing an interface between an electrode and a solid polymer electrolyte in the electrochemical device of the present invention.

FIG. 3 is a schematic cross-sectional view showing an interface between another electrode and a solid polymer electrolyte in the electrochemical device of the present invention.

FIG. 4 is a schematic sectional view showing an interface between still another electrode and a solid polymer electrolyte in the electrochemical device of the present invention.

FIG. 5 is a schematic sectional view showing an interface between still another electrode and a solid polymer electrolyte in the electrochemical device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st electrode 1 '2nd electrode 2 Electrolyte 3 Polymer solid electrolyte 4 Powder electrode material 5 Conductive material 6 Binder 7 Current collector

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H01M 10/40 H01M 4/80 C // H01M 4/80 H01G 9/00 301G

Claims (6)

[Claims] 1. An electrochemical device comprising two or more solid electrodes and a solid polymer electrolyte, wherein an electrolytic solution is interposed between the solid electrode and the solid polymer electrolyte. 2. The electrochemical device according to claim 1, wherein one or more of the solid electrodes is formed of a porous material. 3. The electrochemical device according to claim 1, wherein the polymer solid electrolyte comprises a polymer of an oxygen-containing compound. 4. The electrochemical device according to claim 1, wherein the solid polymer electrolyte is a solid polymer electrolyte containing a solvent. 5. The electrochemical device according to claim 4, wherein at least one kind of the solvent has the same component as at least one kind of a solvent constituting an electrolytic solution interposed between the electrode and the solid polymer electrolyte. 6. The electrochemical device according to claim 1, wherein the electrolyte oozes from the solid polymer electrolyte.