JP2005251563A - Ion conductor and electrochemical device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide ion conductor of which ion conductivity is high as it keeps large amount of electrolyte, whose electrolyte hardly leaks out, of which electrolyte solvent has no confinement, of which electrolyte supporter density can be raised, and which has high electron insulation property, high mechanical strength, high heat resistivity, processability and function as separator, and to provide an electrochemical device using it. <P>SOLUTION: The ion conductor with the ion conductivity of 10<SP>-3</SP>S/cm or more, has organic polymer chosen from a constellation consisting of polyamide, polyurethane and polyurea, complex with inorganic compound chosen from a constellation consisting of silica and metal oxide, and the electrolyte supported by the complex. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ionic conductor and an electrochemical device using the ionic conductor.

As a member used between electrodes of batteries, electric double layer capacitors (electric double layer capacitors), etc., a solid material has been developed that does not require a structural material that prevents short-circuiting between electrodes and that does not cause electrolyte leakage. It's getting on. The material used for these needs to have a high level of high ion conductivity as an ionic conductor and two functions of structural stability and workability as a separator. Such materials include intrinsic polymer electrolytes (all solid type) and polymer gel electrolytes. However, among these electrolytes, intrinsic polymer electrolytes basically have low ionic conductivity (less than 10 ⁻⁴ S / cm at room temperature), and therefore have not yet been put into practical use as polymer electrolytes used at room temperature.

On the other hand, the polymer gel electrolyte has a feature of higher ionic conductivity than the intrinsic polymer electrolyte. As an example of the gel electrolyte, a homogeneous system in which an organic polymer such as polyethylene oxide, polyacrylonitrile, or polyvinylidene fluoride is swollen by an electrolytic solution obtained by dissolving a supporting electrolyte (LiClO ₄ , quaternary ammonium salt, etc.) in a polar solvent. (For example, see Patent Documents 1 and 2), a structure system in which an organic polymer such as polyolefin, polyethylene oxide, polyacrylonitrile, or polyvinylidene fluoride is made into a porous body, and an electrolytic solution is held in the micropores of the porous body (For example, refer patent documents 3 and 4) and what impregnated electrolyte with the net-like support body which consists of a polymer which does not have electronic conductivity (for example, refer patent document 5) can be illustrated.

Although the homogeneous gel electrolyte does not easily leak, the ionic conductivity is low because the amount of electrolyte retained is about five times that of the organic polymer at the maximum, and the ionic conductivity of the electrolyte alone (10 ⁻³ S / cm or more). In addition, from the viewpoint of compatibility between the organic polymer as the electrolytic solution holder and the solvent, there is a problem that the type of the solvent of the electrolytic solution is limited depending on the type of the organic polymer used. For example, when an aqueous electrolyte solution is used, the ionic conductivity is as high as 10 ⁻² S / cm or more, but it cannot be used under a high voltage because the decomposition voltage is as low as 2 V or less. On the other hand, the organic electrolyte has a high decomposition voltage of 2 V or higher, while the ionic conductivity is in the order of 10 ⁻³ S / cm, which is inferior to the aqueous solution system. As described above, although the electrochemical characteristics vary depending on the type of the electrolytic solution, there is no electrolytic solution holder that can be applied to any electrolytic solution using any polar solvent.

  In addition, the structural gel electrolyte has a problem that the electrolytic solution is likely to leak because the electrolytic solution exists in a liquid state. In addition, there is a drawback that it still does not reach the ionic conductivity of the electrolyte alone. Therefore, in order to increase the ionic conductivity, it is necessary to increase the porosity of the porous body of the organic polymer when increasing the amount of the electrolyte solution retained. However, increasing the porosity of the porous body decreases the strength of the gel electrolyte. However, there is a problem that the function as a separator becomes insufficient.

In addition, with any type of polymer gel electrolyte, it is not always sufficient to satisfy both the film properties such as bending resistance and heat resistance required for a structure in which a short circuit cannot occur as a separator, and high ion conductivity. Absent. In addition, when used as a secondary battery or an electric double layer capacitor, no material has been found that can be satisfied at a high level with respect to chemical deterioration and solvent resistance due to repeated charge and discharge.
JP 2001-351832 A JP-A-11-149825 JP-T 8-509100 Publication Japanese National Patent Publication No. 9-500485 JP 2000-11758 A

  Therefore, the purpose of the present invention is to increase the amount of electrolyte retained regardless of the type of solvent of the electrolyte, thereby making it possible to increase the ionic conductivity, and the retained electrolyte is less likely to leak, It is possible to increase the concentration of the supporting electrolyte in the electrolyte without limiting the type of solvent of the electrolyte, and it has high electronic insulation, strength, heat resistance, processability, and functions as a separator. An object is to provide a conductor and an electrochemical device using the same. Moreover, it is providing the manufacturing method which can manufacture the ion conductor which has said characteristic easily.

That is, the ionic conductor of the present invention is a composite of at least one organic polymer selected from the group consisting of polyamide, polyurethane and polyurea, and at least one inorganic compound selected from silica and metal oxides, And having an ionic conductivity of 10 ⁻³ S / cm or more.

Here, the average particle diameter of the inorganic compound is 1 μm or less, and the content of the inorganic compound in the composite (100 mass%) is preferably 20 to 80 mass%.
The complex includes an organic solution (A) obtained by dissolving one compound selected from the group consisting of a dicarboxylic acid halide, a dichloroformate compound, and a phosgene compound in an organic solvent, an alkali silicate, An aqueous solution (B) in which at least one compound selected from the group consisting of metal oxides, metal hydroxides, and metal carbonates and a diamine is dissolved in water, the metal element having one of the metal elements is an alkali metal It is desirable that the reaction product be obtained by contacting

Moreover, it is preferable that the holding amount of the electrolytic solution is 500 to 2000 parts by mass with respect to 100 parts by mass of the composite.
The composite preferably has a pulp shape having a fiber diameter of 20 μm or less and an aspect ratio of 10 or more.

The method for producing an ionic conductor according to the present invention includes an organic solution (A) obtained by dissolving one compound selected from the group consisting of a dicarboxylic acid halide, a dichloroformate compound, and a phosgene compound in an organic solvent, and silicic acid. Alkali, at least one compound selected from the group consisting of metal oxides, metal hydroxides and metal carbonates, having two or more metal elements and one of the metal elements is an alkali metal, and diamine in water A composite synthesis step of contacting the aqueous solution (B) dissolved in the solution to obtain a composite of an organic polymer and an inorganic compound;
And an impregnation step of impregnating the composite with an electrolytic solution and retaining the electrolytic solution in the composite.

  The electrochemical device of the present invention is characterized by using the ionic conductor of the present invention.

The ionic conductor of the present invention can increase the amount of electrolyte retained regardless of the type of solvent of the electrolyte, thereby increasing the ionic conductivity, and the retained electrolyte is less likely to leak. It is possible to increase the concentration of the supporting electrolyte in the electrolyte without limitation on the type of solvent in the electrolyte, and it has high electronic insulation, strength, heat resistance, processability, and also functions as a separator. .
Moreover, according to the manufacturing method of the ion conductor of this invention, such an ion conductor can be manufactured easily.

  In addition, when the electrochemical device of the present invention using such an ionic conductor is used for, for example, a battery, in addition to being able to increase the current, the active material utilization efficiency, low-temperature operating characteristics, etc. Excellent. In addition, when used in an electric double layer capacitor, it has excellent charge / discharge characteristics, low temperature operation characteristics, etc. due to its low internal resistance. In addition, it can be used as an electrolyte for an electrochromic device.

Hereinafter, the present invention will be described in detail.
<Ionic conductor>
The ionic conductor of the present invention is a composite of an organic polymer and an inorganic compound in which an electrolytic solution is held and an ionic conductivity is 10 ⁻³ S / cm or more.

(Complex)
The composite of an organic polymer and an inorganic compound in the present invention is an organic polymer in which an inorganic compound of submicrometer to nanometer order (that is, an average particle size of 1 μm or less) is in a fine particle shape, a three-dimensional network, or a two-dimensional network It has an organic / inorganic nanocomposite structure finely dispersed in. The prior art describes the addition of inorganic fine particles of silica or alumina to intrinsic polymer electrolytes or polymer gel electrolytes for the purpose of improving the film strength and pressure resistance characteristics of ion conductors (for example, patents) Document 2 and Patent Document 3) are also found, but the composite used in the present invention is essentially different from a mixture obtained by simply mixing an organic polymer and an inorganic compound. Further, it is also essentially different from a composite of an organic material and an inorganic compound gel obtained by a so-called sol-gel method.

The organic polymer is at least one selected from the group consisting of polyamide, polyurethane and polyurea.
Polyamide is obtained, for example, by polycondensation of a dicarboxylic acid halide and a diamine, which will be described later, and its structure depends on the type of these monomers used for polycondensation.
Polyurethane is obtained, for example, by polycondensation of a dichloroformate compound and a diamine, which will be described later, and its structure depends on the type of these monomers used for polycondensation.
Polyurea is obtained, for example, by polycondensation of a phosgene compound and a diamine, which will be described later, and its structure depends on the type of these monomers used for polycondensation.

The inorganic compound is at least one selected from silica (SiO ₂ ) and metal oxides.
Examples of the metal oxide include aluminum oxide, tin oxide, zirconium oxide, zinc oxide, manganese oxide, molybdenum oxide, tungsten oxide, and tellurium oxide. From the viewpoint of the amount of electrolyte solution that can be retained and the magnitude of ionic conductivity, the inorganic compound is preferably silica or aluminum oxide.

Moreover, it is preferable that the average particle diameter of the inorganic compound in the said composite is 1 micrometer or less, and the content rate of the inorganic compound in a composite (100 mass%) is 20-80 mass%.
The inorganic compound can be made into fine particles having an average particle diameter of 1 μm or less according to the composite synthesis method described below. In addition, from the viewpoint of the electrolyte retention characteristics in the composite and the particles are less likely to fall off, the average particle size of the inorganic compound is preferably 500 nm or less, more preferably 100 nm or less. According to the composite synthesis method described below, the inorganic compound content can be set to a high content of 20 to 80% by mass. In addition, from the viewpoint of balance between electrolyte retention characteristics as a function of the ionic conductor of the composite and processability as a separator, and film properties such as bending resistance and heat resistance, the content of the inorganic compound is It is preferable that it is 30-70 mass% inside. Normally, when an inorganic compound is combined with an organic polymer using a mixing device such as an extruder, the inorganic compound is uniformly dispersed with a fine dispersion of 1 μm or less and a high content of 20% by mass or more. This is extremely difficult due to the self-aggregation characteristic of inorganic compounds.
The shape of the composite is preferably a pulp (bent microfiber) shape having a fiber diameter of 20 μm or less and an aspect ratio of 10 or more.

(Electrolyte)
The electrolytic solution in the present invention is composed of a supporting electrolyte and a solvent for dissolving the supporting electrolyte.
The solvent may be either aqueous or non-aqueous. In addition to water, propylene carbonate, dimethyl carbonate, 2-ethoxyethanol, 2-methoxymethanol, isopropyl alcohol, N-methylpyrrolidone, dimethylacetamide, dimethylformamide, acetonitrile, butyronitrile. And polar organic solvents such as glutaronitrile, dimethoxyethane, γ-butyrolactone, ethylene glycol, and propylene glycol. In the case of an aqueous system, in order to prevent solidification at 0 ° C. or lower and to use an ionic conductor even under a low temperature condition, the non-aqueous solvent is compatible with water. The solvent to be used can be used in a compatible state.

Examples of the supporting electrolyte include lithium salts such as lithium chloride, lithium bromide, lithium iodide, lithium perchlorate, lithium nitrate, lithium sulfate, lithium borofluoride, and lithium hexafluorophosphate; sodium chloride, sodium bromide, iodine Alkali metal halides such as sodium chloride, potassium chloride, potassium bromide, potassium iodide; tetrabutylammonium bromide, tetrabutylammonium chloride, ammonium borofluoride, tetraethylammonium borofluoride, tetrabutylammonium borofluoride, tetraethylammonium perchlorate Examples thereof include ammonium salts such as tetra-n-butylammonium perchlorate, inorganic acids such as sulfuric acid, hydrochloric acid and perchloric acid.
The concentration of the supporting electrolyte may be appropriately set according to the use and required performance of the ion conductor of the present invention, and is not particularly limited.

<Production method of ion conductor>
The ionic conductor of the present invention includes, for example, an organic solution in which one compound selected from the group consisting of a dicarboxylic acid halide, a dichloroformate compound, and a phosgene compound (hereinafter also referred to as a monomer) is dissolved in an organic solvent (A And at least one compound selected from the group consisting of metal oxides, metal hydroxides and metal carbonates, having an alkali silicate, two or more metal elements, and one of the metal elements is an alkali metal (Hereinafter, also referred to as an alkali metal-containing inorganic compound) and an aqueous solution (B) in which a diamine is dissolved in water, and a composite synthesis step for obtaining a composite of an organic polymer and an inorganic compound; It can be produced by a method having an impregnation step of impregnating a liquid and holding the electrolyte in the composite.

(Composite synthesis process)
In the composite synthesis step, for example, the monomer in the organic solution (A) and the diamine in the aqueous solution (B) are rapidly polycondensed by an agitation operation at room temperature and normal pressure for about 10 seconds to several minutes, and organic A polymer is obtained with good yield. At this time, the alkali metal in the alkali metal-containing inorganic compound such as an alkali silicate acts as a removing agent for the hydrogen halide generated during the polycondensation of the monomer and the diamine, thereby promoting the production of the organic polymer. Simultaneously with this reaction, the alkali metal-containing inorganic compound has its alkali metal component removed, and when alkali silicate is used, it contains silica (glass), and when other metal compounds are used, it has a metal element other than alkali metal. By converting to an inorganic compound, it becomes insoluble in an organic solution or water and precipitates as a solid. Furthermore, at this time, the formation of organic polymer by polycondensation of monomer and diamine and the precipitation of inorganic compound occur in parallel without causing only one of them, so fine particles in submicrometer to nanometer order In addition, a composite in which an inorganic compound in a three-dimensional network or a two-dimensional network is finely dispersed in an organic polymer is obtained.

  Examples of the dicarboxylic acid halide in the organic solution (A) include acid halides of aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, and sebacic acid; aromatic dicarboxylic acids such as isophthalic acid and terephthalic acid. An acid halide; or an acid halide of an aromatic dicarboxylic acid obtained by substituting hydrogen of an aromatic ring with a halogen atom, a nitro group, an alkyl group, or the like. These can be used alone or in combination of two or more.

  Examples of the dichloroformate compound in the organic solution (A) include 1,2-ethanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and 1,8-octanediol. All the hydroxyl groups of aliphatic diols such as chlorogenated by phosgenation treatment; resorcin (1,3-dihydroxybenzene), hydroquinone (1,4-dihydroxybenzene), 1,6-dihydroxynaphthalene, 2, 2'-biphenol, bisphenol S, bisphenol A, tetramethylbiphenol, etc., all of the hydroxyl groups of dihydric phenols having two hydroxyl groups on one or more aromatic rings are chlorogenated by phosgenation treatment Can be mentioned. These can be used alone or in combination of two or more.

Examples of the phosgene compound in the organic solution (A) include phosgene, diphosgene and triphosgene. These may be used alone or in combination of both species.
In the present invention, by selecting a monomer in the organic solution (A), the type of the organic polymer that is the matrix of the complex can be changed. By reaction with polyamide in the case of using a dicarboxylic acid halide as a monomer, polyurethane in the case of using a dichloroformate compound, polyurea in the case of using a phosgene compound, by reaction with a diamine in the aqueous solution (B). Can be obtained.

  The organic solvent used in the organic solution (A) can be used without particular limitation as long as it does not react with the various monomers and diamines and dissolves the various monomers in the organic solution (A). Among these, those incompatible with water include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as n-hexane, halogenated hydrocarbons such as chloroform and methylene chloride, and fats such as cyclohexane. Typical examples of the cyclic hydrocarbons that are compatible with water include ethers such as tetrahydrofuran, ketones such as acetone and methyl ethyl ketone, and alkyl acetates such as ethyl acetate and propyl acetate. .

When an organic solvent (A) that is incompatible with water is used, the resulting polycondensation reaction is interfacial polycondensation that occurs only at the interface between the organic solution (A) and the aqueous solution (B). In this case, since the molecular weight of the obtained organic polymer can be easily increased, a fiber-shaped (pulp-like) composite is easily obtained. Moreover, a high-strength long fiber can also be obtained by spinning while pulling up the composite film produced at the interface between the organic solution (A) and the aqueous solution (B). On the other hand, when an organic solvent that is compatible with water is used as the organic solvent in the organic solution (A), polycondensation occurs in an emulsified state of the organic solvent and water, so that a powder-shaped composite can be easily obtained. It is done.
Regardless of which organic solvent is used, the resulting composite is in the form of powder or pulp, and has a larger external surface area than the bulk shape, so that the electrolyte can be easily and quickly processed without pulverization or the like. And can be held in large quantities.

  The diamine in the aqueous solution (B) can be used without particular limitation as long as it reacts with each monomer in the organic solution (A) to produce an organic polymer. Specifically, aliphatic diamines such as 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, 1,8-diaminooctane; m-xylylenediamine , P-xylylenediamine, m-phenylenediamine, p-phenylenediamine, 1,5-diaminonaphthalene, 1,8-diaminonaphthalene, 2,3-diaminonaphthalene, and other aromatic diamines; Examples include aromatic diamines substituted with atoms, nitro groups, alkyl groups, and the like. These may be used alone or in combination of two or more.

  The monomer concentration in the organic solution (A) and the diamine concentration in the aqueous solution (B) are not particularly limited as long as the polycondensation reaction proceeds sufficiently, but from the viewpoint of bringing each monomer into good contact, 0.01 A concentration range of ˜3 mol / L, particularly 0.05 to 1 mol / L is preferred.

Examples of the alkali silicate in the aqueous solution (B) include those represented by the composition formula of A ₂ O · nSiO ₂ such as water glass No. 1, No. 2, No. 3, etc. described in JIS K 1408. Here, A is an alkali metal, and the average value of n is 1.8-4. Moreover, the metasilicate alkali (for example, 1 type, 2 types of sodium metasilicate) whose average value of n is 0.8-1.1 can also be used. Water glass (alkali silicate) by acting as a remover of the acid generated when the alkali metal compound contained in the alkali silicate is polycondensed between the monomer in the organic solution (A) and the diamine in the aqueous solution (B) Promotes the polycondensation of the monomer and the diamine, and at the same time becomes a raw material for the inorganic compound constituting the composite by being converted to solid glass (silica) insoluble in the polar solvent.

A metal oxide, a metal hydroxide and a metal carbonate (hereinafter also referred to as an alkali metal-containing metal compound) having two or more metal elements in the aqueous solution (B) and one of the metal elements being an alkali metal ) Can include compounds that can be represented by the general formula AxMyBz. Here, A is an alkali metal element, M is at least one metal element selected from the group consisting of metal elements other than alkali metals, and B is at least selected from the group consisting of O, CO ₃ and OH. It is one kind of group, and x, y, and z are numbers that allow bonding of A, M, and B. The compound represented by the general formula AxMyBz is preferably a compound that dissolves in water and exhibits basicity. The alkali metal contained in the alkali metal-containing metal compound, like the alkali metal compound in the alkali silicate, also acts as a remover of the acid generated during the polycondensation, thereby promoting the polycondensation of the monomer and diamine. At the same time, it is converted into a metal compound insoluble in a polar solvent, thereby becoming a raw material for the inorganic compound constituting the composite.

  Among the alkali metal-containing metal compounds, the compound in which B in the above general formula is O includes sodium zincate, sodium aluminate, sodium chromite, sodium molybdate, sodium stannate, sodium tellurite, titanic acid. Sodium composite oxides such as sodium, sodium vanadate, sodium tungstate; potassium zincate, potassium aluminate, potassium chromite, potassium molybdate, potassium stannate, potassium manganate, potassium tantalate, potassium tellurite, Potassium composite oxides such as potassium ferrate, potassium vanadate, potassium tungstate, potassium goldate, and potassium silverate; lithium composite oxides such as lithium aluminate, lithium molybdate, and lithium stannate, and rubidium composite oxides , Cesi Beam composite oxide and the like.

Examples of the alkali metal-containing metal compound in which B in the above general formula contains both CO ₃ and OH groups include zinc carbonate potassium, nickel carbonate potassium, zirconium carbonate potassium, cobalt potassium carbonate, and tin carbonate potassium. Since these alkali metal-containing metal compounds are used after being dissolved in a polar solvent such as water, they may be hydrates. Moreover, these can be used individually or in combination of 2 or more types. Moreover, you may use simultaneously with the above-mentioned alkali silicate.

  The concentration of the alkali metal-containing inorganic compound in the aqueous solution (B) is determined to some extent by the monomer concentration in the organic solution (A) and the diamine concentration in the aqueous solution (B), but maintains a high yield of the complex. In addition, the amount of 1 to 200 g / L is desirable for the purpose of preventing side reaction between the monomer and water in the organic solution (A) that may be generated due to excessive heat generation during polycondensation.

  Alkali metal-containing inorganic compounds also have the effect of accelerating the polycondensation reaction by neutralizing the hydrogen halide produced during the polycondensation reaction. In this case, an acid acceptor such as sodium hydroxide, potassium hydroxide, sodium carbonate, or potassium carbonate may be added to the aqueous solution (B), or the acid acceptor solution may be added later to the synthesis system. Good.

(Electronic insulation)
When the ionic conductor of the present invention is used for a battery electrolyte or a separator of an electric double layer capacitor, the ionic conductor needs to have an electronic insulating property, so the organic polymer and the inorganic compound of the composite have an electronic conductivity. Preferably no material is used.
In the case of using alkali stannate such as sodium stannate and potassium stannate and potassium tin carbonate, which can provide tin oxide having electronic conductivity, as a raw material of the inorganic compound, and making the inorganic compound a high proportion of 60% by mass Care is required for use, but other raw materials for inorganic compounds can be used without any problem. In addition, even when the organic polymer is any of polyamide, polyurethane, and polyurea, it can be used without any problem because it does not have electron conductivity.

  As an organic solution (A), an acid halide of an aliphatic dicarboxylic acid is dissolved in a solvent incompatible with water as an organic solution (A) as a raw material for an ion conductor composite that is particularly suitable for battery electrolytes and separators for electric double layer capacitors As the aqueous solution (B), a system in which aliphatic diamine and alkali silicate or alkali aluminate are dissolved can be used. In addition, as raw materials for inorganic compounds in the aqueous solution (B), alkali metal composite oxides such as sodium zincate, sodium molybdate, sodium tellurite, sodium titanate, potassium molybdate, zinc carbonate potassium, potassium zirconium carbonate An organic-inorganic composite suitable for this application can also be obtained by using an alkali metal composite carbonate such as.

  The production apparatus used for production of the composite is not particularly limited as long as it is an apparatus that can satisfactorily contact the organic solution (A) and the aqueous solution (B). Is possible. Specific examples of continuous devices include “Fine Flow Mill FM-15” manufactured by Taihei Koki Co., Ltd., “Spiral Pin Mixer SPM-15” manufactured by the same company, or INDAG Machinenbau GmbH. "Dynamic mixer DLM / S215 type" manufactured by the company can be mentioned. As a batch-type device, it is necessary to make good contact between the organic solution (A) and the aqueous solution (B). Therefore, a general-purpose stirring device having a propeller blade, a Max blend blade, a Faudler blade, etc. Can be used.

  When an aliphatic diamine is used as the diamine in the aqueous solution (B) and an aliphatic dicarboxylic acid halide is used as the monomer in the organic solution (A), a strong gel may be generated by polycondensation. In that case, it is preferable to use a mixer having a high shearing force for crushing the gel and advancing the reaction, and examples of the mixer include a blender manufactured by osterizer.

  The polycondensation reaction between the monomer in the organic solution (A) and the diamine in the aqueous solution (B) proceeds sufficiently in a temperature range of, for example, −10 to 50 ° C. near room temperature. Therefore, the temperature at which the organic solution (A) and the aqueous solution (B) are brought into contact with each other is set to a temperature range of about −10 to 50 ° C. near room temperature. At this time, neither pressurization nor decompression is required. The polycondensation reaction is usually completed in 10 minutes or less, depending on the type of monomer used and the reaction apparatus.

(Impregnation process)
The ionic conductor of the present invention can be obtained by impregnating and holding the electrolytic solution in the composite thus obtained. The composite obtained in the composite synthesis step is obtained in the state of a wet cake containing a polar solvent mainly composed of about 4 to 7 times the mass of water. The composite in a wet cake state is impregnated with an electrolytic solution. Alternatively, the polar solvent may be replaced with an electrolytic solution, or the wet cake composite may be once dried, and the dry composite may be impregnated with the electrolytic solution. However, when the wet cake-like composite is dried, the composite is firmly solidified by hydrogen bonds derived from the polar groups of the organic polymer, and the composite becomes difficult to absorb the electrolytic solution. Therefore, it is preferable to impregnate the wet cake composite with the electrolytic solution and replace the polar solvent with the electrolytic solution.

  As a method for impregnating and holding the electrolyte in the composite, the composite is poured into a pre-prepared electrolytic solution and sufficiently dispersed, and then filtered, or the electrolytic solution is circulated through the composite. Examples of such a method include impregnating the composite, and dispersing the composite in the electrolytic solution, followed by distilling off the polar solvent originally contained, but the method is not limited thereto. Since the composite in the present invention has extremely high electrolyte retention characteristics by an estimation mechanism described later, it is 5 to 20 times the mass only by performing a simple operation such as charging, dispersing and filtering the composite in the electrolyte. It can be set as the wet cake holding the electrolyte solution. Moreover, since the composite is obtained in the form of pulp or powder, the composite can be easily dispersed in the electrolytic solution by using a general-purpose batch type stirring layer.

(Processing characteristics)
When the composite has a fiber shape, it has paper-making properties, and when it has a powder, it has coating properties. The composite itself has processability and is easy to handle. In particular, when the composite has a fiber shape, a wet cake sheet having high tensile strength, flexibility, and high followability to bending can be obtained by filtering a liquid in which an electrolyte is dispersed in the composite. For this reason, there is no need to compound or mix with other materials, and even if an ion conductor made of only the present composite is used, it can also serve as a separator.
For the purpose of forming a wet cake impregnated with and holding the electrolyte in the composite, and further shaping the wet cake into a desired shape, binders such as binders and various resins are required to hold the electrolyte. Further, it may be contained within a range that does not impair the electronic insulating properties.

(Electrolytic solution retention mechanism)
Since the ionic conductor of the present invention can hold a large amount of electrolyte solution having a mass of 5 to 20 times, it can have almost the same ionic conductivity as the electrolyte solution in which the supporting electrolyte is dissolved. Keeps insulation.
The electrolyte solution retention characteristics of the ionic conductor of the present invention are manifested by the chemical characteristics and shape factors of the organic polymer and inorganic compound components of the composite.

The role of the inorganic compound in the composite is as follows.
The inorganic compound of the composite is silica or metal oxide, and these have extremely high affinity with polar solvents. Moreover, the content rate of an inorganic compound is as high as 20-80 mass%, and also the magnitude | size of an inorganic compound is very small with the order of submicrometer to nanometer (namely, average particle diameter is 1 micrometer or less).

  The fact that the inorganic compound is in the order of submicrometer to nanometer (that is, the average particle size is 1 μm or less) means that an infinite number of fine particles, a three-dimensional network, or a two-dimensional network inorganic compound with a very large surface area per unit mass. It means that it exists in. A large surface of these inorganic compounds imparts a strong affinity to a polar solvent, so that the composite exhibits a large amount of electrolyte retention characteristics. Therefore, the average particle size of the inorganic compound is preferably 500 nm or less, more preferably 100 nm or less. In addition, since the composite can have an extremely high content of the inorganic compound as high as 80% by mass, the above-mentioned properties of the inorganic compound can be further enhanced (a mechanism for holding the chemisorbing electrolytic solution by the inorganic compound).

In particular, when the inorganic compound is silica or aluminum oxide, the particle size of the particulate inorganic compound is extremely small, about 10 nanometers, and a network structure in which the fine particles of the inorganic compound are partially connected is formed. This has been clarified by observation with a transmission electron microscope (TEM). With this structure, the composite has a high specific surface area (that is, porosity) of 50 to 150 m ² / g, and can have higher electrolyte solution retention. As described above, the raw materials of the inorganic compound that can impart such a structure are alkali silicate and alkali aluminate (physical adsorption electrolyte holding mechanism).

On the other hand, the role of the organic polymer with respect to the electrolyte retention is as follows.
Polyamide, polyurethane, and polyurea, which are the organic components of the composite, are derived from the high polarity of amide bonds, urethane bonds, and urea bonds that they frequently have, and have a higher affinity for polar solvents than polyolefins. . For this reason, the organic polymer component also contributes to electrolyte retention (a mechanism for retaining a chemisorbing electrolyte by an organic polymer). However, since this mechanism alone does not have an electrolyte solution holding capacity of 500 parts by mass or more with respect to 100 parts by mass of its own weight, it has sufficient ionic conductivity when using only an organic polymer component material having no inorganic compound. It is not possible to produce an ionic conductor that does not leak electrolyte. Further, since the organic polymer is a matrix (base material), an inorganic compound having high self-aggregation property due to its high polarity is made into a finely dispersed state and can be handled.

  In addition, in particular, when the organic polymer is an aliphatic polyamide, the molecular weight can be easily increased. Therefore, by applying a high shear force during the synthesis of the composite, a pulp shape (fiber diameter of 20 μm or less and aspect ratio of 10 or more) Bending microfibers). When the composite has such a pulp shape, water can be firmly held between the fibers of the composite, so that it is possible to further improve the electrolyte retention characteristics. As described above, the organic polymer capable of providing this structure includes a system in which an acid halide of an aliphatic dicarboxylic acid is dissolved as an organic solvent (A) in a solvent incompatible with water, and an aliphatic as an aqueous solution (B). This is a case where a system in which diamine is dissolved in water is brought into contact. In addition, when the organic polymer component of the composite is an organic polymer other than aliphatic polyamide, the composite shape is a powder, but even in this case, the outer surface area of the material is high compared to the block-shaped composite, so that the high It has electrolyte retention characteristics and electrolyte absorption rate (electrolyte retention by complex shape).

  Thus, since the ionic conductor of the present invention can retain most of polar solvents including water by the above-described mechanism, there is no limitation on the type of polar solvent in the electrolytic solution. Moreover, even if the concentration of the supporting electrolyte in the electrolytic solution is increased, the electrolytic solution retention characteristics are not significantly affected.

(Heat-resistant)
In addition, a composite of an organic polymer and an inorganic compound has high heat resistance due to the reinforcing effect of the inorganic compound on the organic polymer (for example, a polyamide composed of polyamide as an organic polymer and silica as an inorganic compound). The composite having a content of 60% by mass does not cause a change in physical properties up to 300 ° C. or higher), and the ion conductor of the present invention in which a polar solvent is held is also excellent in heat resistance. On the other hand, the organic-inorganic composite gel produced by the sol-gel method generally cannot maintain the gel state stably at a high temperature of 100 ° C. or higher due to changes in physical properties such as curing accompanying the dehydration reaction of the gel.

  In addition, the organic-inorganic composite in the present invention is characterized by having extremely high solvent resistance. For example, when a composite composed of polyamide as an organic polymer and silica as an inorganic compound is used, it is extremely stable in liquids other than cresols that dissolve polyamide and strong alkaline solutions that dissolve silica. Therefore, for example, even a strong acid solution in which hydrochloric acid, sulfuric acid, or nitric acid is dissolved can be used as the electrolytic solution. Further, when the ion conductor of the present invention is used as a member of an electrochemical device such as a secondary battery or an electric double layer capacitor, there is almost no deterioration of the composite even if repeated charge / discharge is performed.

  As described above, the ion conductor of the present invention is one of the features that can be used alone, but for the purpose of improving the strength of the ion conductor during film formation, it is possible to use a binder, various resins, etc. The binder may be contained within a range that does not impair the required properties.

<Battery>
Various batteries can be illustrated as an example of the electrochemical device of the present invention. The battery includes a positive electrode, a negative electrode, and an electrolyte composed of the ionic conductor of the present invention.
Hereinafter, the battery of the present invention will be described taking a lithium ion secondary battery as an example.
FIG. 1 is a cross-sectional view showing an example of the battery of the present invention. The battery 1 includes a positive electrode current collector 2 to which a negative electrode terminal (not shown) is connected, a positive electrode 3 in contact with the positive electrode current collector 2, a negative electrode current collector 4 to which a negative electrode terminal (not shown) is connected, and a contact therewith. The negative electrode 5 to be formed, the electrolyte 6 sandwiched between the positive electrode 3 and the negative electrode 5, and the exterior material 7 for storing them are roughly constituted.

As the positive electrode active material of the positive electrode 3, conventionally known materials are used, for example, transition metal oxides such as lithium manganate, lithium nickelate and lithium cobaltate; conductive polymers such as polyacetylene, polyphenylene, polyaniline and polypyrrole. Etc. are used.
As the negative electrode active material of the negative electrode 5, conventionally known materials are used, and for example, carbon materials that can store lithium ions, lithium metal, lithium alloys, conductive polymers, and the like are used.

As the positive electrode current collector 2 and the negative electrode current collector 4, conventionally known ones are used. For example, a metal such as aluminum, a carbon material, or the like is used.
The electrolyte 6 is made of the ionic conductor of the present invention. In the case of a lithium ion secondary battery, an electrolyte containing lithium ions such as lithium perchlorate is used as a supporting electrolyte for an electrolyte solution to be held in an ionic conductor, and a nonaqueous solvent such as propylene carbonate is used as a solvent. It is done.
As the exterior material 7, a conventionally known material is used. For example, a metal case, a resin case, a resin film, or the like is used.

<Electric double layer capacitor>
As another example of the electrochemical device of the present invention, an electric double layer capacitor can be exemplified. The electric double layer capacitor includes a separator made of the ionic conductor of the present invention and a polarizable electrode disposed so as to face the separator.
FIG. 2 is a cross-sectional view showing an example of the electric double layer capacitor of the present invention. The electric double layer capacitor 10 includes a separator 11, a pair of polarizable electrodes 12 disposed so as to face each other via the separator 11, a gasket 13 that holds the separator 11 and the polarizable electrode 12 from the side surface, and the polarizable electrode 12. And a pair of current collectors 14 in contact with each other.

  The separator 11 is made of the ionic conductor of the present invention. In the case of an electric double layer capacitor, a conventionally known electrolyte is used as an electrolyte to be held in an ionic conductor. An organic electrolytic solution in which a quaternary ammonium salt is dissolved is used.

As the polarizable electrode 12, a conventionally known electrode is used. For example, activated carbon or an electrode obtained by impregnating activated carbon into a solid with a binder is used.
As the current collector 14, a conventionally known one is used, and for example, a conductive resin imparted with conductivity by carbon powder or the like is used.
As the gasket 13, a conventionally known one is used, and for example, a resin material is used.

  Hereinafter, the present invention will be described more specifically with reference to examples. Unless otherwise specified, “part” means “part by mass”.

(Synthesis Example 1: Synthesis of silica / polyamide composite)
1.58 parts of 1,6-diaminohexane and 9.18 parts of water glass No. 3 were added to 81.1 parts of ion-exchanged water, followed by stirring at 25 ° C. for 15 minutes to obtain a homogeneous transparent aqueous solution (B). An organic solution (A) in which 2.49 parts of adipoyl chloride was dissolved in 44.4 parts of toluene while the aqueous solution (B) was charged into a blender bottle manufactured by Osterizer at room temperature and stirred at 10,000 rpm. Was added dropwise over 20 seconds. The generated gel was crushed with a spatula and further stirred at 10,000 rpm for 40 seconds. The liquid in which the pulp-like product obtained by this operation was dispersed was filtered under reduced pressure on a filter paper having a mesh size of 4 μm using a Nutsche having a diameter of 90 mm. The product on Nutsche was dispersed in 100 parts of methanol, stirred for 30 minutes with a stirrer, and filtered under reduced pressure for washing treatment. Subsequently, the same washing operation was performed using 100 parts of distilled water, followed by filtration under reduced pressure to obtain a pure white silica / polyamide composite wet cake (wet cake (1)).

(Synthesis Example 2: Synthesis of aluminum oxide / polyamide composite)
As an aqueous solution (B), 1.58 parts of 1,6-diaminohexane and 2.26 parts of sodium aluminate (Na ₂ O / Al ₂ O ₃ molar ratio = 1.13) are placed in 81.1 parts of ion-exchanged water, A pure white aluminum oxide / polyamide composite wet cake (wet cake) in the same manner as described in Example 1 except that the homogeneous transparent aqueous solution (B) obtained by stirring at room temperature for 15 minutes was used. (2)) was obtained.

(Synthesis Example 3: Synthesis of zirconium oxide / polyamide composite)
As an aqueous solution (B), 1.58 parts of 1,6-diaminohexane and 3.79 parts of potassium zirconium carbonate (K ₂ [Zr (OH) ₂ (CO ₃ ) ₂ ]) are placed in 38.5 parts of ion-exchanged water. A pure white zirconium oxide / polyamide composite wet cake (wet cake (3)) was prepared in the same manner as described in Example 1 except that the homogeneous aqueous solution (B) obtained by stirring was used. Obtained.

(Synthesis Example 4: Synthesis of polyamide containing no inorganic compound)
Pale yellow containing no inorganic compound in the same manner as described in Example 1, except that 1.18 parts of sodium hydroxide was used instead of water glass 3 as the aqueous solution (B). Polyamide wet cake (wet cake (4)) was obtained.

(Preparation of electrolyte)
As an electrolytic solution for a secondary battery using an organic polar solvent, 1.06 parts of lithium perchlorate as a supporting electrolyte was dissolved in 11.9 parts of propylene carbonate as a solvent to obtain a uniform transparent solution.
Further, as an electrolytic solution for an electric double layer capacitor using an organic polar solvent, 3.29 parts of tetrabutylammonium borofluoride as a supporting electrolyte is dissolved in 11.9 parts of propylene carbonate as a solvent to obtain a uniform transparent solution. Obtained.
Further, 0.98 parts of concentrated sulfuric acid was added to 10.0 parts of ultrapure water as an aqueous electrolyte solution for battery and electric double layer capacitor to obtain a uniform transparent solution.
In any of the above electrolytic solutions, the concentration of each supporting electrolyte in the liquid corresponds to 1 mol / L. Using these electrolytic solutions, the ionic conductivity when only the electrolytic solution was used was measured.

<Evaluation of material properties of composite and polyamide>
The composite obtained by the above operation and the polyamide not containing an inorganic compound were subjected to the measurement or test of the following items, and the results obtained are shown in Table 1.

(1) Measuring method of inorganic compound content (ash content):
The measuring method of the content rate of the inorganic compound contained in each material is as follows.
After each material is completely dried, it is precisely weighed (composite mass), calcined in air at 600 ° C. for 3 hours, completely burned off the organic polymer component, measured after calcining, and ash mass (= inorganic compound) Mass). The inorganic compound content was calculated from the following formula.
Inorganic compound content (mass%) = (ash content / composite mass) × 100

(2) Verification of inorganic compound species in the composite (FP method):
200 g of a dispersion in which each material was dispersed in distilled water at a concentration of 0.2 g / dL was filtered under reduced pressure on a filter paper having a mesh size of 4 μm using a Nutsche having a diameter of 55 mm. The obtained cake was hot-pressed at 170 ° C. and 5 MPa / cm ² for 2 minutes to produce a nonwoven fabric. The obtained non-woven fabric was rich in flexibility and contained no inorganic compound, and no particles dropped out even when bent.

  A non-woven fabric was cut into 3 cm square, and this was set in a measurement holder having an opening of 20 mm in diameter to obtain a measurement sample. The sample was subjected to total elemental analysis using a fluorescent X-ray analyzer “ZSX100e” manufactured by RIKEN. By using the obtained results of total elemental analysis, the sample data of the measurement sample (sample shape; film, compound type; oxide, correction component; cellulose, mass value per area of the measured sample) is given to the apparatus. The ratio of elements in the complex was calculated by the FP method (Fundamental Parameter method; a method in which sample uniformity and surface smoothness are assumed and correction is performed using constants in the apparatus and components are quantified). The amount of the inorganic compound calculated from the FP method showed good agreement with the value calculated from the ash content measuring method of (1). From this value, the target inorganic compound (silica when water glass is used as raw material, aluminum oxide when sodium aluminate is used, zirconium oxide when potassium zirconium carbonate is used) is contained in a large amount in the composite. It was verified that it was present (40% by mass or more).

  In this measurement, alkali metal (sodium in synthesis examples 1 and 2 and potassium in synthesis example 3) was detected only in 0.03% by mass or less in any sample. It was revealed that the alkali metal removal and solidification reaction of the inorganic compound were carried out according to the predicted reaction mechanism.

(3) Measurement of particle size of inorganic compound in composite and observation of dispersion state:
The composite was hot-pressed for 2 hours under conditions of 170 ° C. and 20 MPa / cm ² to obtain a flake made of the composite having a thickness of about 1 mm. This was made into an ultrathin section having a thickness of 75 nm using a microtome. The obtained section was observed with a transmission electron microscope “JEM-200CX” manufactured by JEOL Ltd. at a magnification of 100,000. It was observed that the inorganic compound was finely dispersed in a bright organic polymer as a dark image. FIG. 3 is a transmission electron micrograph of the silica / polyamide composite, FIG. 4 is a transmission electron micrograph of the aluminum oxide / polyamide composite, and FIG. 5 is a transmission type of the zirconium oxide / polyamide composite. It is an electron micrograph.

  Subsequently, the particle size of 100 inorganic compound particles was measured, and the average value was defined as the inorganic compound average particle size. In this observation, in the silica / polyamide composite, it was observed that an inorganic compound (silica) of about 10 nm was network-like, that is, a three-dimensional network was formed and finely dispersed in the polyamide. In the aluminum oxide / polyamide composite, it was observed that about 10 nm of aluminum oxide was layered, that is, a two-dimensional network was formed and finely dispersed in the polyamide. On the other hand, in the zirconium oxide / polyamide composite, it was observed that each of the zirconium oxide particles in the vicinity of 850 nm was dispersed independently.

(4) Production of ion conductor:
(4-1) Production of an ion conductor impregnated with an electrolytic solution using an organic polar solvent:
(Solvent: propylene carbonate, supporting electrolyte: lithium perchlorate)
About 10 g of the obtained wet cakes (1) to (4) are each dispersed in 100 g of ultrapure water and subjected to washing treatment by repeating vacuum filtration three times to obtain a wet cake having ultrapure water. About 10 g of was obtained. 100 g of propylene carbonate was added to the wet cake, and a vacuum treatment was performed at 120 ° C. for 2 hours while stirring to remove only water in the wet cake. About 10 g of wet cakes (1a) to (4a) each having only propylene carbonate as a liquid component were obtained by filtering the propylene carbonate in which the obtained pulp was dispersed under reduced pressure at 0.02 MPa for 5 minutes.
After measuring the mass of the wet cake (wet mass), it was dried under reduced pressure at 280 ° C. for 2 hours to remove propylene carbonate, and the mass was measured (dry mass). From these numerical values, the propylene carbonate holding amounts of the wet cakes (1a) to (4a) are obtained. Moreover, the solid content rate was computed by the following formula.
Solid fraction (mass%) = (dry mass / wet mass) × 100

  The total amount of propylene carbonate retained and the amount of propylene carbonate added is calculated as total propylene carbonate, so that the concentration of lithium perchlorate as the supporting electrolyte is 1 mol / L. And added. This was dispersed and dissolved by stirring, then filtered under reduced pressure at 0.02 MPa for about 3 minutes, and adjusted to have a thickness of 300 μm, thereby organic solvent electrolysis containing 1 mol / L of supporting electrolyte. Wet cake sheets (1b) to (4b) impregnated with the liquid were obtained. The obtained wet cake was uniform, free from defects such as holes, and rich in strength. Moreover, no leakage of the electrolyte solution was observed from the wet cake sheet. In addition, since any of the organic-inorganic composites used this time was excellent in organic solvent resistance, the composite did not deteriorate at all during this step. However, the wet cake sheet (1b) to (3b) is a wet cake sheet in which the filtration under reduced pressure at 0.02 MPa is performed only for 30 seconds and the content of the electrolyte solution based on propylene carbonate with respect to 100 parts by mass of the solid is 900 parts by mass or more. ), No leakage of the electrolyte was observed, but in the wet cake sheet (4b) containing no inorganic component, leakage of the electrolyte was observed between the pulps constituting the sheet.

(4-2) Production of ion conductor impregnated with electrolytic solution using organic polar solvent:
(Solvent: propylene carbonate, supporting electrolyte: tetrabutylammonium borofluoride)
A wet cake sheet impregnated with an organic solvent electrolyte containing 1 mol / L of supporting electrolyte was obtained in the same manner as in (4-1) except that the supporting electrolyte was tetrabutylammonium borofluoride. The wet cake sheet containing this electrolytic solution was also excellent in electrolytic solution retention characteristics, free from leakage of the electrolytic solution, and was uniform and rich in strength.

(4-3) Production of ion conductor impregnated with aqueous electrolyte:
(Solvent: ultrapure water, supporting electrolyte: sulfuric acid)
After washing with ultrapure water similar to (4-1), the obtained wet cake was dried at 150 ° C. for 2 hours, and ultrapure wet cake was obtained in the same manner as in (4-1). The amount of water retained and the solid content rate were calculated.
The total amount of ultrapure water added and the ultrapure water added was calculated as the total amount of ultrapure water, and added so that the concentration of sulfuric acid in the liquid was 1 mol / L. Except for this, it was impregnated with a water-based electrolyte containing 1 mol / L sulfuric acid in the same manner as in (4-1), excellent in electrolyte retention characteristics, no leakage of electrolyte, uniform and excellent in strength A wet cake sheet was obtained. None of the organic-inorganic composites used this time were excellent in acid resistance, and thus the composites did not deteriorate at all during this step.
However, the wet cake sheet (1b) to (1b) to (2) which are filtered under reduced pressure at 0.02 MPa only for 30 seconds and the electrolyte solution content of ultrapure water based on 100 parts by mass of the solid content is 1000 parts by mass or more. In 3b), no leakage of the electrolyte solution was observed, but in the wet cake sheet (4b) containing no inorganic component, leakage of the electrolyte solution was observed between the pulps constituting the sheet.

(5) Measurement of electrolyte retention with respect to composite mass:
After performing the same operation as (4-1) and (4-2) and measuring the mass of each obtained wet cake sheet (wet cake sheet (1b) and (2b)) (cake mass), 15 times of propylene carbonate was added, and dispersion washing at room temperature for 30 minutes and vacuum filtration were repeated three times to remove the supporting electrolyte and obtain a wet cake having only propylene carbonate substituted with propylene carbonate alone. The wet cake was dried under reduced pressure at 280 ° C. for 2 hours, and the mass was measured (dry mass). From these numerical values, the retention amount of the electrolytic solution (electrolytic solution retention amount) with respect to 100 parts by mass of the composite (or polyamide) was calculated by the following equation.
Electrolyte retention amount (parts by mass) = {(cake mass−dry mass) / dry mass} × 100

  Also, the same operation as in (4-3) is performed, and the operation of removing the supporting electrolyte (sulfuric acid) from the obtained wet cake sheet (wet cake sheet (3b)) is performed using ultra pure water and replaced with ultra pure water. Then, the amount of electrolyte solution retained was calculated by the same method as above except that the cake was washed and dried at 150 ° C. for 2 hours.

(6) Measurement of ionic conductivity:
The ion conductivity at 25 ° C. of each ion conductor was measured by an AC impedance method using an impedance analyzer 1260 type manufactured by Toyo Technica and a liquid sample holder. Moreover, the ionic conductivity of various liquid electrolytes was measured similarly.

Example 1
Using the wet cake (1) which is the silica / polyamide composite obtained in Synthesis Example 1, various electrolytic solutions are held by the methods described in (4-1), (4-2) and (4-3). A wet cake sheet was obtained. The ionic conductivity of the obtained wet cake sheet was measured by the above method. Moreover, the electrolyte solution content hold | maintained at each wet cake sheet | seat was measured as electrolyte solution content with respect to 100 mass parts of composites.

(Example 2)
Using the wet cake (2) which is the aluminum oxide / polyamide composite obtained in Synthesis Example 2, various electrolyte solutions were prepared by the methods described in (4-1), (4-2) and (4-3). A retained wet cake sheet was obtained. The ionic conductivity of the obtained wet cake sheet was measured by the above method. Moreover, the electrolyte solution content hold | maintained at each wet cake sheet | seat was measured as electrolyte solution content with respect to 100 mass parts of composites.

(Example 3)
Using the wet cake (3) which is the zirconium oxide / polyamide composite obtained in Synthesis Example 3, various electrolytes were prepared by the methods described in (4-1), (4-2) and (4-3). A retained wet cake sheet was obtained. The ionic conductivity of the obtained wet cake sheet was measured by the above method. Moreover, the electrolyte solution content hold | maintained at each wet cake sheet | seat was measured as electrolyte solution content with respect to 100 mass parts of composites.

(Comparative Example 1)
Using the wet cake (4) which is a polyamide having no inorganic compound obtained in Synthesis Example 4, various electrolyte solutions were prepared by the methods described in (4-1), (4-2) and (4-3). A retained wet cake sheet was obtained. The ionic conductivity of the obtained wet cake sheet was measured by the above method. Moreover, the electrolyte solution content hold | maintained at each wet cake sheet | seat was measured as electrolyte solution content with respect to 100 mass parts of composites.

  The results of Examples 1 to 3 and Comparative Example 1 are shown in Table 2.

(Comparative Example 2)
As a comparative example corresponding to a homogeneous polymer gel electrolyte, a gel electrolyte was prepared by the following method according to the method of Example 2 in JP-A-11-149825. A material obtained by mixing polyvinylidene fluoride, hexafluoropropylene, and tetrafluoroethylene in a polymer composed of 60:15:25 mol% and a silica filler of 25 mass% of the polymer was dissolved in 2-butanone, A film having a thickness of 200 μm was obtained by a coating method using an applicator. The obtained film was immersed in an electrolytic solution in which 1 mol / L LiPF ₄ (supporting electrolyte) was dissolved in propylene carbonate at room temperature for 2 hours, whereby the electrolytic solution was added to 100 parts by mass of the rubbery copolymer. A gel electrolyte film containing 80 parts by mass was obtained. When the ionic conductivity of the obtained film was measured according to the method of (6), it was 6.5 × 10 ⁻⁴ S / cm. Although the immersion time was extended to 6 hours for the purpose of increasing the electrolyte content, there was no significant change in the electrolyte content and ionic conductivity.

(Comparative Example 3)
As a comparative example corresponding to a structural polymer gel electrolyte, a gel electrolyte was prepared by the following method according to the method of Example 1 in JP-T-8-509100. In a polymer solution obtained by dissolving 1.5 parts of a copolymer of polyvinylidene fluoride and hexafluoropropylene in 9 parts of tetrahydrofuran (THF) solution, 1 mol / L LiPF ₄ was added to a mixed solution of ethylene carbonate and propylene carbonate in a mass ratio of 1: 1. 1.5 g of an electrolytic solution in which (supporting electrolyte) was dissolved was introduced. This was stirred for 30 minutes while being heated at 60 ° C., and THF was removed while dissolving the electrolyte in the polymer solution, thereby obtaining a gel electrolyte having an electrolyte in a minute gap due to the removal of THF. . A 100 μm-thick film of the electrolyte was obtained by a coating method using an applicator. When the ion conductivity of the obtained film was measured according to the method of (6), it was 3.7 × 10 ⁻⁴ S / cm. Further, the electrolytic solution content with respect to 100 parts of the polymer of this comparative example corresponded to 100 parts. Electrolyte content of this comparative example When an attempt was made to increase the amount of the electrolyte solution relative to the polymer solution, the electrolyte solution leaked from the film and could be retained when the electrolyte solution content was 120 parts or more. There wasn't.

  Table 3 shows the results of Comparative Examples 2 and 3 and the results of using the lithium perchlorate electrolyte for the propylene carbonate of Example 1.

As can be seen from Examples 1 to 3 above, the ionic conductor of the present invention is 700 with respect to 100 parts by mass of the composite without leaking the electrolyte regardless of the solvent of the electrolyte and the type of the supporting electrolyte. A large amount of the electrolytic solution over part by mass could be retained. Therefore, it had a very high ionic conductivity close to the ionic conductivity of the electrolyte only. Further, the ion conductor of the present invention was easily processed into a sheet shape. On the other hand, in Comparative Example 1, since the polymer did not have an inorganic compound, the amount of electrolyte solution retained was low, and the ionic conductivity was also inferior to each example. In addition, it is inferior to Examples 1 to 3 in that it does not have a reinforcing effect on the organic compound of the inorganic compound, and it has been impossible to achieve both ion conductivity, heat resistance, and sheet strength. Further, in Comparative Examples 2 and 3, since the amount of the electrolytic solution that can be held with respect to the polymer mass is small, the ionic conductivity could not be increased to 10 ⁻³ S / cm or more.

  The ionic conductor of the present invention can increase the amount of electrolyte solution retained, thereby making it possible to increase ionic conductivity, the retained electrolyte solution is difficult to leak, and the type of solvent in the electrolyte solution is limited. In addition, the concentration of the supporting electrolyte in the electrolytic solution can be increased, and the strength and heat resistance are high, and the separator also has a function. Therefore, the ion conductor of the present invention is suitably used as an electrochemical device such as a battery electrolyte, an electric double layer capacitor separator, and an electrochromic element electrolyte.

It is sectional drawing which shows an example of the battery which is an electrochemical device of this invention. It is sectional drawing which shows an example of the electrical double layer capacitor which is the electrochemical device of this invention. It is a transmission electron micrograph of a silica / polyamide composite. 2 is a transmission electron micrograph of an aluminum oxide / polyamide composite. 2 is a transmission electron micrograph of a zirconium oxide / polyamide composite.

Explanation of symbols

1 Batteries (electrochemical devices)
10 Electric double layer capacitor (electrochemical device)

Claims (7)

A composite of at least one organic polymer selected from the group consisting of polyamide, polyurethane and polyurea; at least one inorganic compound selected from silica and metal oxide; and an electrolyte solution retained in the composite Have
An ionic conductor having an ionic conductivity of 10 ⁻³ S / cm or more.   The average particle diameter of the said inorganic compound is 1 micrometer or less, The content rate of the inorganic compound in the said composite body (100 mass%) is 20-80 mass%, The ion conductor of Claim 1.   The complex is an organic solution (A) in which one compound selected from the group consisting of a dicarboxylic acid halide, a dichloroformate compound, and a phosgene compound is dissolved in an organic solvent, an alkali silicate, and two or more metal elements An aqueous solution (B) in which at least one compound selected from the group consisting of metal oxides, metal hydroxides and metal carbonates and diamines are dissolved in water, wherein one of the metal elements is an alkali metal The ionic conductor according to claim 1, wherein the ionic conductor is a reaction product obtained by contacting the ionic conductor.   The ion conductor according to any one of claims 1 to 3, wherein a holding amount of the electrolytic solution is 500 to 2000 parts by mass with respect to 100 parts by mass of the composite.   5. The ion conductor according to claim 1, wherein the composite has a pulp shape with a fiber diameter of 20 μm or less and an aspect ratio of 10 or more. An organic solution (A) obtained by dissolving one compound selected from the group consisting of a dicarboxylic acid halide, a dichloroformate compound, and a phosgene compound in an organic solvent; an alkali silicate; a metal having two or more metal elements Contacting at least one compound selected from the group consisting of metal oxides, metal hydroxides and metal carbonates, wherein one of the elements is an alkali metal, and an aqueous solution (B) in which diamine is dissolved in water; A composite synthesis step for obtaining a composite of an organic polymer and an inorganic compound;
An impregnation step of impregnating the composite with an electrolytic solution and retaining the electrolytic solution in the composite. An electrochemical device using the ionic conductor according to any one of claims 1 to 5.

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