JP2018142444A - Separator for electrochemical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for prolonging the lifetime of an electrochemical element compatibly with reduction of internal resistance.SOLUTION: The present invention relates to a separator for electrochemical element containing organic polymers and an inorganic compound. The separator for electrochemical element is characterized in that the inorganic compound contains an oxide and/or a hydroxide having any other metal element than Al, Zn, Pb, Sn, Ga, In and Bi of which the solubility in water at 20°C is equal to or less than 2×10g/100 g. A content of the organic polymers is equal to or more than 15 mass% in 100 mass% of the separator.SELECTED DRAWING: None

Description

The present invention relates to a separator for an electrochemical element. More specifically, the present invention relates to a separator suitably used for a secondary battery or the like having an electrode that undergoes a shape change with charge / discharge.

In recent years, the importance of batteries has increased rapidly in many industries, from small portable devices to large-scale applications such as automobiles. New battery systems that have advantages mainly in terms of capacity, energy density, and secondary battery use. Have been developed and improved. For example, zinc negative electrodes using zinc species as negative electrode active materials have been studied for a long time with the spread of batteries, and in particular, air / zinc primary batteries, manganese / zinc primary batteries, silver / zinc primary batteries have been put into practical use, Widely used in the world.
However, when an electrode that undergoes a change in shape with charge / discharge of a zinc negative electrode or the like is used for the storage battery, there is a problem that the positive electrode and the negative electrode are short-circuited by dendrite formed on the electrode surface, and the battery cannot be charged / discharged.

Many technical developments have been made for such problems. For example, a zinc-alkali secondary battery obtained by forming a magnesium oxide porous layer on the surface of a zinc negative electrode has been disclosed (see, for example, Patent Document 1). .)

By the way, it is possible to improve the oxidation resistance of the separator on the positive electrode side, to prevent deterioration of the hydrophilic group of the separator on the positive electrode side, and to improve the oxygen gas absorption reaction on the negative electrode side, thereby improving the alkali life. An alkaline secondary battery is disclosed in which an inorganic substance is present on the positive electrode side of the separator or on the positive electrode for the purpose of forming a secondary battery (see Patent Document 2). In addition, for the purpose of producing a separator for an electrochemical device having excellent manufacturing stability, few pinholes, and low internal resistance, a nonwoven fabric substrate mainly composed of synthetic fibers having a specific average fiber diameter, and a specific average A separator for an electrochemical device comprising an inorganic particle layer laminate containing magnesium hydroxide having a particle size is disclosed (see Patent Document 3).

JP-A-57-163963 JP 2001-250529 A Japanese Patent No. 6033933

As described above, various methods have been developed to extend the life of the battery by suppressing dendrite growth of the battery having an electrode that undergoes a change in shape with charge and discharge of a zinc negative electrode or the like. There is also a demand for realizing a battery having low internal resistance, with sufficiently high conductivity of ions such as hydroxide ions involved in the battery reaction (hereinafter also simply referred to as ion conductivity). . Moreover, it is desired that the electrochemical element other than the battery has a long life and sufficiently high ion conductivity.

This invention is made | formed in view of the said present condition, and aims at providing the method of coexisting with the lifetime improvement of an electrochemical element, and low internal resistance.

The inventors of the present invention have studied various materials that can extend the lifetime of an electrochemical element, and formed a separator for an electrochemical element containing an organic polymer and an oxide and / or hydroxide at a certain ratio or more. . Such a separator for an electrochemical element has a positive electrode and a negative electrode that suppress dendrite growth in a battery having an electrode in which the gap in the separator is sufficiently reduced by an organic polymer of a certain ratio or more, and the shape changes with charge / discharge. It is possible to suppress a short circuit. Such a separator for electrochemical elements is excellent in durability even when used for other electrochemical element applications such as a separator for water electrolysis. In the separator for an electrochemical element, when the present invention uses an oxide or hydroxide that is not amphoteric hydroxide or amphoteric oxide and has low solubility in water as inorganic particles, dendrite growth inhibition is achieved. While exhibiting performance and durability over time, the ionic conductivity of the separator is sufficiently high and its resistance is sufficiently low, making it suitable for forming electrochemical devices with low internal resistance. The present inventors have arrived at the present invention by conceiving that the above-mentioned problems can be solved brilliantly.

That is, the present invention is a separator for an electrochemical device containing an organic polymer and an inorganic compound, and the inorganic compound has a solubility in water at 20 ° C. of 2 × 10 ⁻² g / 100 g or less, Al, Zn, Electrochemical which includes oxides and / or hydroxides having metal elements other than Pb, Sn, Ga, In and Bi, and the content of the organic polymer is 15% by mass or more in 100% by mass of the separator It is a separator for elements.

The separator for an electrochemical element of the present invention has the above-described configuration, has sufficient permeability for hydroxide ions, and can exhibit dendrite suppression performance or durability over time. It can be suitably used for an element, especially a battery separator configured to include an electrode that undergoes a change in shape with charge / discharge of a zinc negative electrode, etc., while extending the life of an electrochemical element and reducing its internal resistance. Can be low.

The present invention is described in detail below.
A combination of two or more preferred embodiments of the present invention described below is also a preferred embodiment of the present invention.

<Electrochemical element separator>
The separator for an electrochemical element of the present invention contains an organic polymer and an inorganic compound, and the inorganic compound has a solubility in water at 20 ° C. of 2 × 10 ⁻² g / 100 g or less, Al, Zn, Pb, Sn , Oxides and / or hydroxides having metal elements other than Ga, In and Bi, and the content of the organic polymer is 15% by mass or more in 100% by mass of the separator.
Thus, by setting the content of the organic polymer to 15% by mass or more, as described above, the gap between the inorganic particles in the separator is sufficiently reduced by the organic polymer, and the growth of dendrite is sufficiently suppressed to sufficiently prevent the positive electrode. Therefore, the electrochemical device can have a long life.

The content of the organic polymer in the separator for electrochemical devices of the present invention is preferably 16% by mass or more from the viewpoint of suppression of dendrite growth and the mechanical strength of the separator in 100% by mass of the separator. More preferably, the content is at least 18% by mass, and even more preferably at least 18% by mass. In addition, workability and productivity can also be improved by containing many organic polymers and obtaining sufficient mechanical strength.
The content is preferably 50% by mass or less, more preferably 45% by mass or less, and still more preferably 40% by mass or less from the viewpoint of ion conductivity.

As described above, since the voids in the separator of the present invention are sufficiently small, the portion on the surface of the inorganic compound particles, which is the interface between the inorganic compound and the organic polymer, becomes a path for hydroxide ions, and the hydroxide ions are selected. Transparent. Here, when the inorganic compound is composed of amphoteric elements or has a high solubility in water, it is composed of amphoteric elements, such as hydrotalcite composed of Al. Layered double hydroxides have a structure in which hydroxide ions, which are ion-conducting species, are coordinated to amphoteric elements, especially in alkaline electrolytes, and some of the hydroxide ions are highly soluble in water. Trapping tends to decrease the mobility of ions and increase the membrane resistance of the separator. When a hydroxide or oxide having a solubility in water at 20 ° C. of 2 × 10 ⁻² g / 100 g or less is used as an inorganic compound, not an amphoteric hydroxide or an amphoteric oxide, as in the present invention, It is possible to sufficiently suppress the trapping of hydroxide ions at the portion on the surface of the inorganic compound particles while sufficiently preventing the dendritic solution from dissolving in the electrolyte and inhibiting the dendrite growth over time. Can be made sufficiently low.
The lower limit of the solubility is not particularly limited, and may be 0 g / 100 g, but is usually 1 × 10 ⁻¹⁵ g / 100 g or more.

Examples of the oxide include palladium oxide, platinum oxide, cerium oxide, iron oxide, copper oxide, hafnium oxide, lutetium oxide, erbium oxide, europium oxide, gadolinium oxide, holmium oxide, cadmium oxide, manganese oxide, magnesium oxide, and oxide. Those containing at least one compound selected from the group consisting of actinium and zirconium oxide are preferred. More preferred are cerium oxide, magnesium oxide, and zirconium oxide. In addition, the cerium oxide may be, for example, a material doped with a metal oxide such as samarium oxide, gadolinium oxide, or bismuth oxide, or a solid solution with a metal oxide such as zirconium oxide. Furthermore, the oxide may be a complex oxide. The oxide is selected from the group consisting of Al, Zn, Pb, Sn, Ga, In, and Bi as long as it is configured using a metal element other than Al, Zn, Pb, Sn, Ga, In, and Bi. Although it may have a trace amount (for example, 1% or less by mass ratio), it is preferable not to have these elements. The oxide may have an oxygen defect.

Examples of the hydroxide include palladium hydroxide, platinum hydroxide, cerium hydroxide, iron hydroxide, copper hydroxide, hafnium hydroxide, lutetium hydroxide, erbium hydroxide, europium hydroxide, gadolinium hydroxide, water Those containing at least one compound selected from the group consisting of holmium oxide, cadmium hydroxide, manganese hydroxide, magnesium hydroxide, actinium hydroxide, and zirconium hydroxide are preferred. More preferred are cerium hydroxide, magnesium hydroxide, and zirconium hydroxide. The hydroxide may be a composite hydroxide. As long as the hydroxide is composed of metal elements other than Al, Zn, Pb, Sn, Ga, In, and Bi, the hydroxide is selected from the group consisting of Al, Zn, Pb, Sn, Ga, In, and Bi. Although it may have a trace amount (for example, 1% or less by mass ratio) of at least one element selected, it is preferable not to have these elements.

Among these, the inorganic compound is more preferably magnesium hydroxide, zirconium hydroxide, or zirconium oxide, and magnesium hydroxide is particularly preferable.

The inorganic compound is preferably in the form of particles, and examples of the shape include fine powder, powder, granule, granule, scale, flat plate, polyhedron, rod, and curved surface.

The inorganic compound in the separator for electrochemical devices of the present invention preferably has an average particle size of 0.3 μm or more and 2 μm or less. By setting the average particle size to 0.3 μm or more, it is possible to reduce the separator voids and suppress short circuit between the positive electrode and the negative electrode due to dendrite growth and to further improve the strength of the separator. In addition, by setting the average particle size to 2 μm or less, it is possible to prevent sedimentation of the inorganic compound during molding by coating to improve dispersibility, and to increase ion passage by increasing the number of ion passages. it can. The average particle diameter is more preferably 0.4 μm or more, and further preferably 0.5 μm or more. The average particle size is more preferably 1.5 μm or less, further preferably 1.2 μm or less, and particularly preferably 1 μm or less.
The particles having an average particle size in the above range may be obtained by, for example, pulverizing the particles with a ball mill or the like, dispersing the obtained coarse particles in a dispersant to obtain a desired particle size, and drying the particles. In addition to the method of screening the particle diameter by sieving the particles, etc., it is possible to produce the particles by a method of optimizing the preparation conditions at the stage of producing the particles and obtaining particles having a desired particle diameter.
The said average particle diameter can be measured by the method of an Example.

Oxidation having metal elements other than Al, Zn, Pb, Sn, Ga, In, and Bi, having a solubility in water at 20 ° C. of 2 × 10 ⁻² g / 100 g or less in the separator for electrochemical devices of the present invention. The content of the product and / or hydroxide is preferably 50% by mass or more from the viewpoint of improving the ionic conductivity of the separator in the mass of 100% by mass of the separator. The content is more preferably 60% by mass or more, and still more preferably 65% by mass or more. In addition, the content is preferably 84% by mass or less, more preferably 83% by mass or less, and still more preferably 82% by mass or less from the viewpoint of the mechanical strength of the separator.

In the separator for an electrochemical device of the present invention, the organic polymer is not particularly limited, and is a conjugated diene polymer, a polyolefin such as polyethylene or polypropylene, an aryl group-containing polymer such as a modified polyolefin or polystyrene; a polyethylene oxide, a polypropylene oxide, or the like. Polyalkylene glycols; hydroxyl group-containing polymers such as polyvinyl alcohol and poly (α-hydroxymethyl acrylate); amide group-containing polymers such as polyamide, nylon, polyacrylamide, polyvinyl pyrrolidone and N-substituted polyacrylamide; polymaleimide and polyimide Imido group-containing polymers such as poly (meth) acrylic acid, polymaleic acid, polyitaconic acid, polymethylene glutaric acid and other carboxy group-containing polymers; poly (meth) Carboxylate-containing polymers such as chlorate, polymaleate, polyitaconate, and polymethylene glutarate; halogen atom-containing polymers such as polyvinyl chloride, polyvinylidene fluoride, and polytetrafluoroethylene; epoxy groups such as epoxy resins Polycondensates of containing compounds; sulfonic acid group-containing polymers; sulfonate-containing polymers; quaternary ammonium base-containing polymers; quaternary phosphonium base-containing polymers; cellulose acetate, hydroxyalkylcellulose (eg, hydroxypropylcellulose), carboxymethylcellulose, Sugars such as chitin, chitosan, alginic acid (salt); amino group-containing polymers such as polyethyleneimine; carbamate group-containing polymers; carbamide group-containing polymers; heterocyclic rings and / or ionized heterocyclic substituent-containing polymers Limer etc. are mentioned, These 1 type (s) or 2 or more types can be used. These polymers may be crosslinked by a known organic crosslinking agent compound and / or inorganic crosslinking agent compound.

Among these, the organic polymer preferably contains a conjugated diene polymer and / or a modified polyolefin. Thereby, especially the separator for electrochemical elements of this invention can express sufficient intensity | strength with time, especially when used for the electrochemical element comprised including an alkaline electrolyte, and can also suppress dendrite growth.
Although the said conjugated diene polymer should just have a structural unit derived from a conjugated diene monomer, it is preferable to further have a structural unit derived from an aromatic vinyl monomer so that it may mention later.

The conjugated diene monomer is preferably an aliphatic conjugated diene monomer. Examples of the aliphatic conjugated diene monomer include 1,3-butadiene, isoprene, 2-chloro-1,3-butadiene, chloroprene and the like. These may be used alone or in combination of two or more. Of these, 1,3-butadiene is preferred. In other words, in the electrochemical device separator of the present invention, the structural unit derived from a conjugated diene monomer is preferably a structural unit derived from 1,3-butadiene.

The conjugated diene polymer is preferably a copolymer further having a structural unit derived from an aromatic vinyl monomer. By using such a conjugated diene polymer, a short circuit between the positive electrode and the negative electrode due to dendrite growth can be further suppressed. Examples of the aromatic vinyl monomer include styrene, α-methyl styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, o-ethyl styrene, m-ethyl styrene, p-ethyl styrene, o-methoxy styrene. , M-methoxystyrene, p-methoxystyrene, o-ethoxystyrene, m-ethoxystyrene, p-ethoxystyrene, o-fluorostyrene, m-fluorostyrene, p-fluorostyrene, o-chlorostyrene, m-chlorostyrene P-chlorostyrene, o-bromostyrene, m-bromostyrene, p-bromostyrene, o-acetoxystyrene, m-acetoxystyrene, p-acetoxystyrene, o-tert-butoxystyrene, m-tert-butoxystyrene, p-tert-butoxys Ren, o-tert-butylstyrene, m-tert-butylstyrene, p-tert-butylstyrene, vinyltoluene and the like may be used, and these may be used alone or in combination of two or more. Styrene and α-methylstyrene are preferable, and styrene is more preferable in that the heat resistance and mechanical strength of the separator for electrochemical devices can be increased. In other words, in the separator for an electrochemical element of the present invention, the structural unit derived from the aromatic vinyl monomer is preferably a structural unit derived from styrene.
For example, it is particularly preferable that the conjugated diene polymer includes a butadiene-derived structural unit and a styrene-derived structural unit, in other words, a styrene-butadiene-based polymer.

In the conjugated diene polymer, the total proportion of the structural unit derived from the conjugated diene monomer and the structural unit derived from the aromatic vinyl monomer is 100% by mass. It is preferably 90% by mass or less, more preferably 15% by mass or more and 80% by mass or less, further preferably 20% by mass or more and 75% by mass or less, and 25% by mass or more and 70% by mass. It is particularly preferred that

The conjugated diene polymer is a structural unit derived from an aliphatic conjugated diene monomer, a structural unit derived from an acid group-containing vinyl monomer other than a structural unit derived from an aromatic vinyl monomer, or a structural unit derived from a (meth) acrylate monomer. In addition, it may have structural units derived from other unsaturated monomers.

The conjugated diene polymer preferably has a structural unit derived from the acid group-containing vinyl monomer, for example. In particular, when a conjugated diene polymer is prepared as a water dispersion by an emulsion polymerization method using a known surfactant, the polymer contains a structural unit derived from an acid group-containing vinyl monomer, so that the polymer with high hydrophobicity can be converted into water. As a result, the amount of the surfactant used to promote water penetration into the binding material portion in the separator can be reduced, and as a result, the binding in the separator can be reduced. The penetration of water into the material portion can be suppressed to a lower level, the penetration of water and ions such as zincate ions into the binding material portion is further reduced, and dendrite growth in the binding material portion can be suppressed. Examples of the acid group-containing vinyl monomer include itaconic acid, acrylic acid, methacrylic acid, fumaric acid, maleic acid, acrylamidomethylpropane sulfonic acid, and styrene sulfonate. These may be used alone. More than one kind may be used in combination, but itaconic acid, acrylic acid, methacrylic acid, fumaric acid and maleic acid are preferred, and itaconic acid, acrylic acid, methacrylic acid and fumaric acid are more preferred.

In 100% by mass of all the structural units constituting the conjugated diene polymer, the mass ratio of the structural unit derived from the acid group-containing vinyl monomer is preferably 0.1% by mass or more, and the conjugated diene polymer is particularly dispersed in water. From the viewpoint of reducing the amount of the surfactant used to promote the penetration of water and ions into the binder part in the separator of the present invention when it is prepared as a body, it is more preferably 0.5% by mass or more. The content is more preferably 1% by mass or more, and particularly preferably 2% by mass or more. The mass ratio is preferably 10% by mass or less from the viewpoint of lowering the hydrophilicity of the conjugated diene polymer and further reducing the penetration of water and ions into the binder part in the separator. % Or less is more preferable, 5% by mass or less is further preferable, and 4% by mass or less is particularly preferable.

It is also one of the preferable forms in the separator of the present invention that the conjugated diene polymer does not have a structural unit derived from an acid group-containing vinyl monomer. As a result, the hydrophilicity of the conjugated diene polymer can be lowered, and the penetration of water and ions into the binder portion in the separator can be reduced. When a surfactant is not used during polymer preparation, such as when preparing a solution of a conjugated diene polymer in a solvent, the amount of surfactant used by introducing a structural unit derived from an acid group-containing vinyl monomer into the polymer There is no need to reduce the amount.

Examples of the (meth) acrylate monomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, T-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylic Examples include acid nonyl, decyl (meth) acrylate, and the like. These may be used alone or in combination of two or more.

In particular, when the electrochemical device separator of the present invention is used for an electrochemical device comprising an alkaline electrolyte, the (meth) acrylic acid ester monomer may be transformed into a structural unit that cannot suppress permeability by hydrolysis. Therefore, from the viewpoint of further improving the stability over time, the mass proportion of the structural unit derived from the (meth) acrylic acid ester monomer is 19% by mass in 100% by mass of all the structural units constituting the conjugated diene polymer. The content is preferably 15% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, and most preferably 0% by mass.

Examples of the other unsaturated monomers include hydroxyl group-containing vinyl monomers such as vinyl alcohol; nitrile group-containing vinyl monomers such as (meth) acrylonitrile; (meth) acrylamide, N-methylol (meth) acrylamide, N-ethylol (meta ) Acrylamide, dimethyl (meth) acrylamide, (meth) acrylamide monomers such as diethyl (meth) acrylamide; halogen atom-containing vinyl monomers such as vinyl chloride, and the like. You may use the above together.

In the separator for an electrochemical element of the present invention, from the viewpoint of suppressing the penetration of water and ions into the binder portion in the separator, the other constituents in 100% by mass of all the structural units constituting the conjugated diene polymer are not suitable. The mass ratio of the structural unit derived from the saturated monomer is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 3% by mass or less, and 1% by mass or less. Is particularly preferable, and is most preferably 0% by mass.

The modified polyolefin is a modified polyolefin such as polyethylene or polypropylene, and is preferably a carboxy-modified polyolefin to which a carboxy group is added, for example.
The carboxy-modified polyolefin may be obtained by polymerization using a carboxy group-containing vinyl monomer as a part of the monomer component of the raw material, as described later, and is obtained by adding an acid group to the polyolefin. However, it is preferably obtained by polymerization using an acid group-containing vinyl monomer as a part of the monomer component of the raw material.
In 100% by mass of all the structural units constituting the carboxy-modified polyolefin, a preferable mass ratio of the structural unit derived from the carboxy group-containing vinyl monomer is a preferable mass ratio of the structural unit derived from the acid group-containing vinyl monomer in the conjugated diene polymer described above. It is the same.

Among these, the organic polymer particularly preferably contains a conjugated diene polymer.
In addition, when the organic polymer contains a conjugated diene polymer or a modified polyolefin, the organic polymer may contain a polymer other than the conjugated diene polymer or the modified polyolefin, but the content is uniform in material. From the viewpoint of the moldability of the separator, it is preferably 10% by mass or less, more preferably 5% by mass or less, out of 100% by mass of the electrochemical element separator of the present invention.
When two or more kinds of polymers other than the conjugated diene polymer and the modified polyolefin are contained, the content is the total amount of the polymers other than the conjugated diene polymer and the modified polyolefin.

The organic polymer preferably has a weight average molecular weight of 10,000 or more and 1,000,000 or less. Thereby, the ion conductivity, flexibility, etc. of the separator for electrochemical devices can be suitably adjusted. The weight average molecular weight is more preferably 20,000 or more and 800,000 or less, and still more preferably 100,000 or more and 500,000 or less.
The said weight average molecular weight can be measured as a weight average molecular weight converted into polystyrene by gel permeation chromatography (GPC) under the following conditions.
Device: HCL-8220GPC manufactured by Tosoh Corporation
Column: TSKgel Super AWM-H
Eluent (LiBr · H ₂ O, phosphoric acid-containing NMP): 0.01 mol / L

The organic polymer preferably has a glass transition temperature (Tg) of −40 ° C. or higher and 50 ° C. or lower. When Tg is less than −40 ° C., the mechanical strength of the separator is lowered, and the effect of suppressing dendrite growth may be reduced. When Tg exceeds 50 ° C., the separator becomes hard and brittle, and when the electrochemical element is formed, the separator is liable to be cracked and the like, which may reduce the life performance of the electrochemical element. The Tg of the organic polymer is more preferably −35 ° C. or higher and 30 ° C. or lower, and further preferably −30 ° C. or higher and 15 ° C. or lower.
The Tg of the organic polymer can be measured with a differential scanning calorimeter.

The said organic polymer can be manufactured by polymerizing the monomer component which forms the structural unit which the polymer mentioned above contains, for example. In addition, you may use a commercial item as said organic polymer.
When the organic polymer is produced by polymerizing monomer components, the polymerization method is not particularly limited. For example, solution polymerization method, aqueous solution polymerization method, emulsion polymerization method, reverse phase suspension polymerization method, suspension polymerization method Examples thereof include a bulk polymerization method. Among these methods, the emulsion polymerization method is preferably used from the viewpoint of easy production.
When the emulsion polymerization method is used as the polymerization method of the monomer component, emulsion polymerization may be performed after mixing the monomer component, the surfactant, and the dispersion medium mainly composed of water. The emulsion and the aqueous medium may be emulsified by stirring to prepare a pre-emulsion, and then emulsion polymerization may be performed. Alternatively, at least one of the monomer component, the surfactant, and the medium and the remaining part of the pre-emulsion may be used. Emulsion polymerization may be performed by mixing with an emulsion. The monomer component, surfactant, and medium may be added all at once, may be added in portions, or may be added dropwise continuously.

Examples of the surfactant include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants, and one or more of these can be used.
Examples of the anionic surfactant include, but are not limited to, alkyl sulfate salts such as ammonium dodecyl sulfate and sodium dodecyl sulfate; alkyl sulfonate salts such as ammonium dodecyl sulfonate, sodium dodecyl sulfonate and sodium alkyl diphenyl ether disulfonate; dodecyl benzene sulfone. Alkyl aryl sulfonate salts such as sodium acid, ammonium dodecylbenzene sulfonate, sodium dodecyl naphthalene sulfonate, etc .; polyoxyethylene alkyl phenyl ether sulfate salts; polyoxyethylene alkyl sulfonate salts; polyoxyethylene alkyl sulfate salts; polyoxyethylene alkylaryl salts Sulfate salts; dialkyl sulfosuccinates; Reel sulfonic acid-formalin condensate; fatty acid salt such as ammonium laurate, sodium stearate; bis (polyoxyethylene polycyclic phenyl ether) methacrylate sulfonate salt, propenyl-alkylsulfosuccinate ester salt, polyoxyethylene (meth) acrylate Sulfonates having an allyl group such as sulfonate salts, (meth) acrylic acid polyoxyethylene phosphonate salts, sulfonate salts of allyloxymethylalkyloxypolyoxyethylene or salts thereof; sulfates of allyloxymethylalkoxyethyl polyoxyethylene Examples include salts.

The nonionic surfactant is not particularly limited. For example, polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, condensate of polyethylene glycol and polypropylene glycol, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid. Examples thereof include monoglycerides, condensates of ethylene oxide and aliphatic amines, allyloxymethylalkoxyethylhydroxypolyoxyethylene, and polyoxyalkylene alkenyl ether.
Although it does not specifically limit as a cationic surfactant, For example, alkyl ammonium salts, such as dodecyl ammonium chloride, etc. are mentioned.
Although it does not specifically limit as an amphoteric surfactant, For example, a betaine ester type surfactant etc. are mentioned.

The amount of the surfactant used in the emulsion polymerization method is 100% by mass of all monomer components used as raw materials for the organic polymer from the viewpoint of reducing water penetration into the organic polymer portion in the separator for electrochemical devices of the present invention. %, Preferably 5% by mass or less, more preferably 3% by mass or less, and 0.1% by mass from the viewpoint of stabilizing the polymerization. Preferably, the content is 0.2% by mass or more, and more preferably 0.5% by mass or more. The amount of the surfactant is the total amount when the surfactant is used for preparing the pre-emulsion and the subsequent emulsion polymerization, and this is the total amount of the surfactant usually contained in the separator of the present invention. Amount. In addition, the organic polymer obtained even if it reduces the usage-amount of surfactant can be made into a stable aqueous dispersion because an organic polymer contains the structural unit derived from an acid group containing vinyl monomer. Therefore, when the organic polymer is prepared as an aqueous dispersion, the organic polymer is stabilized with stable water by combining the above-described preferred mass ratio of the structural unit derived from the acid group-containing vinyl monomer and the above-mentioned preferred amount of the surfactant. The dispersion and the penetration of water and ions into the binder part in the separator can be sufficiently suppressed. For example, in 100% by mass of all the structural units constituting the organic polymer, the mass ratio of the structural unit derived from the acid group-containing vinyl monomer is 0.5% by mass or more, and the total monomer component 100 used as a raw material for the organic polymer The amount of the surfactant is preferably 5% by mass or less with respect to mass%.

A polymerization initiator can be used for the polymerization of each monomer component. As the polymerization initiator, those usually used can be used, and are not particularly limited as long as they generate radical molecules by heat. Examples of the polymerization initiator include persulfates such as potassium persulfate, ammonium persulfate, and sodium persulfate; 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine], 2,2 Water-soluble azo compounds such as' -azobis (2-amidinopropane) dihydrochloride, 4,4'-azobis (4-cyanopentanoic acid); thermal decomposition initiators such as hydrogen peroxide; hydrogen peroxide and ascorbic acid , T-butyl hydroperoxide and Rongalite, potassium persulfate and metal salts, redox initiators such as ammonium persulfate and sodium bisulfite, and the like, and one or more of these can be used. .

The amount of the polymerization initiator used is preferably 0.02% by mass or more and 2% by mass or less with respect to 100% by mass of all monomer components used as raw materials for the organic polymer. More preferably, they are 0.05 mass% or more and 1 mass% or less.

For the polymerization of each monomer component, a chain transfer agent may be used for the purpose of adjusting the weight average molecular weight. The chain transfer agent is not particularly limited, and examples thereof include 2-ethylhexyl thioglycolate, tert-dodecyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, mercaptoacetic acid, mercaptopropionic acid, 2-mercaptoethanol, α-methyl. A styrene dimer etc. are mentioned, These 1 type (s) or 2 or more types can be used.

When a chain transfer agent is used, the amount used may be appropriately set according to the type and amount of the monomer used, the polymerization reaction conditions such as the polymerization temperature and concentration, the molecular weight of the target organic polymer, and the like. However, for example, it is preferably 10% by mass or less, more preferably 5% by mass or less, and more preferably 3% by mass or less, with respect to 100% by mass of all monomer components used as raw materials for the organic polymer. More preferably. From the viewpoint of adjusting the weight average molecular weight, it is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and further preferably 0.05% by mass or more. The amount of the chain transfer agent used is the total amount when the chain transfer agent is used for preparing the pre-emulsion and for the subsequent emulsion polymerization.

The temperature of the polymerization reaction for producing the organic polymer is not particularly limited as long as the polymerization reaction proceeds, but it is preferably performed at 20 ° C. or more and 100 ° C. or less. More preferably, it is 40 degreeC or more and 90 degrees C or less.
The time for the polymerization reaction is not particularly limited, but is preferably 1 hour or more and 10 hours or less in consideration of productivity. More preferably, it is 1 hour or more and 5 hours or less.

When an emulsion polymerization method using water as a medium is used as the polymerization method of the monomer component, the average particle size in the aqueous dispersion of the organic polymer obtained as latex particles is from the viewpoint of forming a uniform separator. The thickness is preferably 20 nm or more, more preferably 50 nm or more, and still more preferably 80 nm or more. From the viewpoint of suppressing the penetration of water and ions into the binder part in the separator, preferably 5000 nm or less, more preferably 1000 nm or less. More preferably, it is 500 nm or less.
The average particle diameter can be measured according to the method described in Examples.

The separator for electrochemical devices of the present invention may contain other components as long as it contains an organic polymer and the above-described oxide and / or hydroxide. Examples of the other components include at least one element or a compound selected from the group consisting of Al, Zn, Pb, Sn, Ga, In, and Bi, and other inorganic materials such as conductive ceramics. Ingredients.
The content of other components in the separator for electrochemical devices of the present invention is preferably 10000 ppm or less, more preferably 1000 ppm or less from the viewpoint of sufficiently exerting the effects of the present invention and the strength of the separator. Preferably, it is 500 ppm or less, more preferably 100 ppm or less.

The separator for an electrochemical element of the present invention has a sufficient amount of voids by containing a certain amount or more of an organic polymer, but voids may exist, for example, the ratio of the void area to the entire cross section of the separator is It is preferable that it is 0.1 to 10%, and it is more preferable that it is 1 to 5%.
The ratio of the area of the gap is as follows: For the separator cross section obtained by cutting vertically, take a 10,000 times magnified photograph of any five locations using a scanning electron microscope, and use image analysis software to It is calculated by calculating the ratio of the occupied void portion.

The thickness of the electrochemical device separator of the present invention is preferably 10 to 1000 μm. If it is thinner than 10 μm, there is a risk that many damages will occur during film formation. On the other hand, if it is thicker than 1000 μm, it is disadvantageous in terms of cost and there is a possibility that the ability of permeating hydroxide ions may be reduced. The film thickness is more preferably 15 μm or more, further preferably 20 μm or more, and particularly preferably 25 μm or more. The film thickness is more preferably 800 μm or less, further preferably 500 μm or less, and particularly preferably 300 μm or less.
The film thickness of the separator for electrochemical devices can be measured according to the method described in Examples.

Resistance of the separator for an electrochemical element of the present invention is preferably 3 [Omega] · cm ² or less, more preferably 2 [Omega · cm ² or less, still more preferably 1.5 [Omega · cm ² or less.
The lower limit of the resistance value is not particularly limited, but is usually 0.3 Ω · cm ² or more.
The resistance value of the separator for electrochemical devices can be measured according to the method described in Examples.

As a method for producing the separator for an electrochemical element of the present invention, a material for forming the separator for an electrochemical element (hereinafter, such a material before film formation is also referred to as an electrochemical element separator material) is prepared. And a step of forming the obtained separator material for an electrochemical element into a film.
In addition, it is the separator material for electrochemical elements containing an organic polymer and an inorganic compound, and the inorganic compound has a solubility in water at 20 ° C. of 2 × 10 ⁻² g / 100 g or less, Al, Zn, Pb, It contains oxides and / or hydroxides having metal elements other than Sn, Ga, In, and Bi, and the content of the organic polymer is 15% by mass or more in 100% by mass of the solid content of the separator material. The separator material for an electrochemical element characterized by the above is also one aspect of the present invention.
Examples of the method for preparing the separator material for an electrochemical element in the present invention include the following methods.
Other components are mixed with the organic polymer and the above-described oxide and / or hydroxide as necessary. For mixing, a mixer, blender, kneader, bead mill, ready mill, ball mill, roll mill or the like can be used. In mixing, water, an organic solvent such as methanol, ethanol, propanol, isopropanol, butanol, hexanol, N-methylpyrrolidone, or a mixed solvent of water and an organic solvent may be added as a medium.

The content ratio of the medium in the separator material for electrochemical elements of the present invention is 15% by mass or more and 60% by mass or less in the total of 100% by mass of the separator material for electrochemical elements from the viewpoint of suppressing film shrinkage during molding. It is preferable. The content is more preferably 25% by mass or more and 50% by mass or less.
When the polymer contained in the electrochemical element separator material is in the form of a dispersion or a solution, a dispersion medium in which the polymer is dispersed or a solvent in which the polymer is dissolved is also included in the medium.

The method of manufacturing the separator from the separator material for electrochemical elements is not particularly limited as long as it is a method of forming into a film shape, a method of rolling the separator material for electrochemical elements with a roll to form a film shape, a flat plate press It is possible to use a method of rolling into a film, a method of coating with a coater such as a comma coater or a slot die coater, or a method of forming into a film such as an injection molding method, an extrusion molding method, or a casting method. it can. These molding methods may be used alone, or two or more methods may be used in combination.
Incidentally, when forming into a film, the amount of the dry separator for an electrochemical element material, it is preferable that a 50 to 300 g / ^{m 2,} and more preferably set to 100 to 200 g / ^{m 2.}
Thus, a method for producing a separator, that is, a step of preparing a separator material for an electrochemical element containing the organic polymer and the above-described oxide and / or hydroxide, and the obtained separator material for an electrochemical element A separator manufacturing method including a step of forming a film into a film is also one aspect of the present invention.

The said manufacturing method may include the process of heating a film | membrane after the process of shape | molding the separator material for electrochemical elements in a film form.
In the heat treatment after forming the film, it is not particularly limited, and the heating temperature may be appropriately set. Moreover, the time of heat processing is not specifically limited, For example, it is preferable to set it as 0.5 minutes or more and 24 hours or less.

By using the electrochemical device separator of the present invention, the lifetime of the electrochemical device can be extended.

In the electrochemical element of the present invention, the above-described separator for electrochemical elements is used as a separator, but another separator may be laminated on the above-described separator for electrochemical elements.
Examples of such separators include nonwoven fabrics, filter paper, polyolefin resins such as polyethylene and polypropylene, fluorine atom-containing resins such as polytetrafluoroethylene and polyvinylidene fluoride, cellulose, fibrillated cellulose, viscose rayon, cellulose acetate, and hydroxyalkyl cellulose. , Aryl group-containing resins such as carboxymethylcellulose, polyvinyl alcohol and polystyrene, polyacrylonitrile resins, polyacrylamide resins, polyamide resins, polyimide resins, (meth) acrylic resins, hydroxyl group-containing resins such as polyisoprenol and poly (meth) allyl alcohol , Polycarbonate resin, polyester resin, polyurethane resin, agar, organic-inorganic composite resin, ion exchange resin, sulfonate-containing resin, quaternary ammonium salt Yes resins, quaternary phosphonium salts containing resin, cycloolefin polymer, vinylon, film made of an inorganic substance such as a ceramic or the like, a porous film or the like obtained by using these materials. These separators may be used alone or in combination of two or more.

For example, the laminated body comprised including the separator for electrochemical elements of this invention, a nonwoven fabric, and / or a porous membrane is also one of this invention.
The entire laminate of the present invention can be suitably used as an electrochemical element separator.

<Electrochemical element>
The separator for an electrochemical element of the present invention or the electrochemical element comprising the laminate of the present invention is also one aspect of the present invention.
The electrochemical element of the present invention is not particularly limited, and examples thereof include a battery, a water electrolysis device, and the like, and among them, a battery having an electrode that undergoes a shape change with charge / discharge is preferable.
As the positive electrode active material constituting the battery of the present invention, those normally used as the positive electrode active material of the primary battery or the secondary battery can be used, and are not particularly limited. For example, oxygen (oxygen is a positive electrode active material and The positive electrode is a perovskite compound capable of reducing oxygen and oxidizing water, cobalt-containing compounds, iron-containing compounds, copper-containing compounds, manganese-containing compounds, vanadium-containing compounds, nickel-containing compounds, iridium-containing compounds, platinum-containing Compound; palladium-containing compound; gold-containing compound; silver-containing compound; air electrode composed of carbon-containing compound); nickel-containing compound such as nickel oxyhydroxide, nickel hydroxide, cobalt-containing nickel hydroxide; manganese dioxide Manganese-containing compounds such as silver oxide; lithium-containing compounds such as lithium cobaltate; iron-containing Compounds; zinc species such as metallic zinc or zinc oxide.
Among these, it is one of the preferred embodiments of the present invention that the positive electrode active material is a nickel-containing compound or a zinc species.
Moreover, it is also one of the suitable embodiments of the present invention that the positive electrode active material such as an air battery or a fuel cell is oxygen.

As the active material for the negative electrode constituting the battery of the present invention, carbon, lithium, sodium, magnesium, zinc, nickel, tin, cadmium, hydrogen storage alloy, silicon-containing material, etc., which are usually used as negative electrode active materials for batteries Can be used. Among these, from the point of exhibiting the characteristics of the separator of the present invention, it is particularly preferable as it is for an active material that may generate dendrite due to an electrode reaction such as zinc, lithium, nickel, magnesium, cadmium and the like. Can be used.
In the battery of the present invention, the positive electrode and / or the negative electrode is preferably an electrode that undergoes a change in shape with charge / discharge of a zinc electrode or the like.

The electrode constituting the battery of the present invention can be manufactured by forming an active material layer on a current collector.
Current collectors that make up the electrode include (electrolytic) copper foil, copper mesh (expanded metal), foamed copper, punched copper, copper alloys such as brass, brass foil, brass mesh (expanded metal), foamed brass, punched brass , Nickel foil, corrosion-resistant nickel, nickel mesh (expanded metal), punching nickel, metallic zinc, corrosion-resistant metallic zinc, zinc foil, zinc mesh (expanded metal), (punched) steel sheet, non-woven fabric with conductivity; Ni · Zn · Copper, copper foil, copper mesh (expanded metal), copper foil, punched copper, brass and other copper alloys, brass foil, brass mesh (expanded metal) with Sn, Pb, Hg, Bi, In, Tl, brass, etc. added ) ・ Foamed brass ・ Punching brass ・ Nickel foil ・ Corrosion resistant nickel ・ Nickel mesh (Expanded) Tal), punched nickel, metallic zinc, corrosion resistant metallic zinc, zinc foil, zinc mesh (expanded metal), (punched) steel sheet, non-woven fabric; plated with Ni, Zn, Sn, Pb, Hg, Bi, In, Tl, brass, etc. (Electrolytic) copper foil, copper mesh (expanded metal), foamed copper, punched copper, copper alloys such as brass, brass foil, brass mesh (expanded metal), foamed brass, punched brass, nickel foil, corrosion-resistant nickel, nickel Mesh (expanded metal), punched nickel, metallic zinc, corrosion-resistant metal zinc, zinc foil, zinc mesh (expanded metal), (punched) steel sheet, non-woven fabric; silver; current collectors and containers for alkaline (storage) batteries and zinc-air batteries The material etc. which are used as are mentioned.

The separator for electrochemical elements of the present invention can be used as a separator, as a solid electrolyte, or as an ion exchange membrane. When the separator of the present invention is not used as a solid electrolyte, an electrolytic solution or a gel electrolyte can be used as an additional electrolyte material. The electrolyte solution constituting the battery (electrochemical element) of the present invention is not particularly limited as long as it is usually used as the battery electrolyte solution, and examples thereof include water-containing electrolyte solutions and organic solvent-based electrolyte solutions. A water-containing electrolyte is preferred. The water-containing electrolytic solution refers to an electrolytic solution using only water as an electrolytic solution raw material (aqueous electrolytic solution) or an electrolytic solution using a solution obtained by adding an organic solvent to water as an electrolytic solution raw material.

As the aqueous electrolyte, an alkaline electrolyte is preferable. Examples of the alkaline electrolyte include potassium hydroxide aqueous solution, sodium hydroxide aqueous solution, lithium hydroxide aqueous solution, zinc sulfate aqueous solution, zinc nitrate aqueous solution, zinc phosphate aqueous solution, and zinc acetate aqueous solution. The aqueous electrolyte solution can be used alone or in combination of two or more.

Moreover, the said water containing electrolyte solution may contain the organic solvent used for an organic solvent type electrolyte solution. Examples of the organic solvent include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, γ-butyrolactone, dimethoxymethane, diethoxymethane, dimethoxyethane, tetrahydrofuran, methyltetrahydrofuran, diethoxyethane, dimethyl sulfoxide, sulfolane, acetonitrile, Examples include benzonitrile, ionic liquid, fluorine-containing carbonates, fluorine-containing ethers, polyethylene glycols, fluorine-containing polyethylene glycols and the like. The organic solvent electrolyte can be used alone or in combination of two or more. The electrolyte of the organic solvent-based electrolytic solution is not particularly limited, but LiPF ₆ , LiBF ₄ , LiB (CN) ₄ , lithium bis (fluorosulfonyl) imide (LiFSI), lithium bis (trifluoromethylsulfonyl) imide ( LiTFSI) and the like are preferable.
In the case of a water-containing electrolyte containing an organic solvent-based electrolyte, the content of the water-based electrolyte is preferably 10% by mass or more and 99.9% with respect to 100% by mass in total of the water-based electrolyte and the organic solvent-based electrolyte. It is 20 mass% or less, More preferably, it is 20 mass% or more and 99.9 mass% or less.

The gel electrolyte constituting the battery of the present invention is not particularly limited as long as it can be used as a battery electrolyte. For example, a solid electrolyte containing a compound similar to the above separator or a solid crosslinked by a crosslinking agent And the like.

The form of the battery of the present invention is a primary battery; a chargeable / dischargeable secondary battery (storage battery); use of mechanical charge (mechanical replacement of a zinc negative electrode); use of a third electrode (as a positive electrode, an electrode suitable for charging) And an electrode suitable for discharge), a fuel cell or the like, but a secondary battery or a fuel cell is preferable. For example, the battery of the present invention is particularly preferably a secondary battery.
The type of the battery of the present invention is not particularly limited, but is a battery using an alkaline electrolyte, such as an alkaline dry battery, a nickel-hydrogen battery, a nickel-cadmium battery, a manganese-zinc battery, a nickel-zinc battery, a fuel cell, an air battery. Preferably there is.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by weight” and “%” means “mass%”.

<Nonvolatile content of organic polymer aqueous dispersion>
1 g of organic polymer aqueous dispersion was weighed and dried with a hot air dryer at a temperature of 110 ° C. for 1 hour.
[Non-volatile content in organic polymer aqueous dispersion (% by mass)]
= ([Mass of residue (g)] ÷ [Mass of organic polymer dispersion (g)]) × 100
Based on the above, the nonvolatile content of the organic polymer aqueous dispersion was determined.

<Average particle diameter of organic polymer dispersion in aqueous dispersion>
The average of the liquid obtained by diluting the organic polymer aqueous dispersion with distilled water was measured by a particle size distribution analyzer (trade name: FPAR-1000, manufactured by Otsuka Electronics Co., Ltd.) by dynamic light scattering, and obtained by cumulant analysis. The particle size was defined as the average particle size in the aqueous dispersion of the organic polymer dispersion.

<Average particle size of inorganic compound particles>
For an inorganic compound dispersion liquid obtained by mixing an inorganic compound (powder) and a 0.2 mass% sodium hexametaphosphate aqueous solution and performing a dispersion treatment using an ultrasonic cleaner, a particle size distribution measuring instrument (dynamic light scattering method) (Trade name: FPAR-1000, manufactured by Otsuka Electronics Co., Ltd.), and the average particle size obtained by cumulant method analysis was defined as the average particle size of the inorganic compound particles.

<Film thickness>
The thickness of the obtained organic polymer / inorganic compound-containing separator and the laminate was measured using a Digimatic Micrometer (manufactured by Mitutoyo Corporation). Arbitrary 10 points were measured, and the average value was taken as the film thickness.

<Resistance value>
The resistance value (Ω · cm ² ) was calculated under the following measurement conditions.
・ Number of charged cells: 5 cells (describe average value)
Cell construction working electrode: Ni plate counter electrode: Ni plate electrolyte: 6.7 mol / L potassium hydroxide aqueous solution saturated with zinc oxide Sample pretreatment: Immersion in the above electrolyte overnight Measurement effective area: φ15 mm
・ Measure AC impedance. After leaving still for 30 minutes in a 25 degreeC thermostat, it measured on condition of the following.
Applied voltage: 10 mV vs. Open circuit voltage frequency range: 100 kHz to 100 Hz
A resistance value was calculated as a resistance value (R) in a unit area from the intercept component (Ra) obtained by the impedance and the intercept component (Rb) when the measurement sample was not added, by the following formula.
R = (Ra−Rb) × 1.77

[Example 1]
Magnesium hydroxide (trade name: 200-06H, manufactured by Kyowa Chemical Industry Co., Ltd., average particle size: 690 nm) 50 parts by mass, styrene-butadiene polymer aqueous dispersion (trade name: Nalstar SR-152, manufactured by Nippon A & L, non-volatile (Minute: 48%, average particle size: 180 nm) 25 parts by mass and 28 parts by mass of ion-exchanged water were weighed and kneaded for 1 hour using a sand mill, followed by filtration and vacuum defoaming to obtain a separator material.
The separator material thus obtained was coated on a silicone-treated surface of a polyethylene terephthalate (PET) film (release film) whose one side was silicone-treated with a comma coater with a coating amount (when dried) of 150 g / m ² . After coating and drying as described above, the obtained coating film was peeled off from the release film, and further heat-treated at 120 ° C. for 20 minutes to obtain an organic polymer / inorganic compound-containing separator.
The obtained organic polymer / inorganic compound-containing separator had a film thickness of 85 μm and a resistance value of 1.0 Ω · cm ² .

[Example 2]
Zirconium oxide (trade name: UEP, manufactured by Daiichi Rare Element Chemical Industry Co., Ltd., average particle size: 760 nm) 50 parts by mass, styrene-butadiene polymer aqueous dispersion (trade name: Nalstar SR-107, manufactured by Nippon A & L, non-volatile) (Minute: 48%, average particle size: 170 nm) 30 parts by mass and 25 parts by mass of ion-exchanged water were weighed and kneaded for 1 hour using a sand mill, followed by filtration and vacuum defoaming to obtain a separator material.
The separator material thus obtained was coated on a silicone-treated surface of a polyethylene terephthalate (PET) film (release film) whose one side was silicone-treated with a comma coater with a coating amount (when dried) of 190 g / m ² . After coating and drying as described above, the obtained coating film was peeled off from the release film, and further heat-treated at 120 ° C. for 20 minutes to obtain an organic polymer / inorganic compound-containing separator.
The obtained organic polymer / inorganic compound-containing separator had a film thickness of 73 μm and a resistance value of 1.4 Ω · cm ² .

[Example 3]
In Example 1, except that 25 parts by mass of the styrene-butadiene-based polymer aqueous dispersion was changed to 85 parts by mass, and 28 parts by mass of ion-exchanged water was changed to 16 parts by mass, the organic polymer / An inorganic compound-containing separator was obtained.
The obtained organic polymer / inorganic compound-containing separator had a thickness of 94 μm and a resistance value of 1.6 Ω · cm ² .

[Example 4]
Magnesium hydroxide (trade name: 200-06H, manufactured by Kyowa Chemical Industry Co., Ltd., average particle size: 690 nm) 50 parts by mass, styrene-butadiene polymer aqueous dispersion (trade name: Nalstar SR-107, manufactured by Nippon A & L Co., Ltd., non-volatile (Minute: 48%, average particle size: 170 nm) 42 parts by mass and 25 parts by mass of ion-exchanged water were weighed and kneaded for 1 hour using a sand mill, followed by filtration and vacuum defoaming to obtain a separator material.
The separator material thus obtained was coated with a comma coater on the silicone-treated surface of a polyethylene terephthalate (PET) film (release film) whose one side was silicone-treated with a comma coater of 120 g / m ² . After coating and drying as described above, the obtained coating film was peeled off from the release film, and further heat-treated at 120 ° C. for 20 minutes to obtain an organic polymer / inorganic compound-containing separator.
The obtained organic polymer / inorganic compound-containing separator had a thickness of 72 μm and a resistance value of 0.89 Ω · cm ² .

[Example 5]
Magnesium hydroxide (trade name: 200-06H, manufactured by Kyowa Chemical Industry Co., Ltd., average particle size: 690 nm) 50 parts by mass, modified polyethylene aqueous dispersion (trade name: Arrow Base SB-1010, manufactured by Unitika Ltd., nonvolatile content: 25 %) Weighed 60 parts by mass and kneaded for 1 hour using a sand mill, followed by filtration and vacuum degassing to obtain a separator material.
The separator material thus obtained was coated on a silicone-treated surface of a polyethylene terephthalate (PET) film (release film) whose one side was silicone-treated with a comma coater and the coating amount was 110 g / m ² . After coating and drying as described above, the obtained coating film was peeled off from the release film, and further heat-treated at 120 ° C. for 20 minutes to obtain an organic polymer / inorganic compound-containing separator.
The obtained organic polymer / inorganic compound-containing separator had a film thickness of 65 μm and a resistance value of 1.5 Ω · cm ² .

[Example 6]
Magnesium hydroxide (trade name: 200-06H, manufactured by Kyowa Chemical Industry Co., Ltd., average particle size: 690 nm) 50 parts by mass, styrene-butadiene polymer aqueous dispersion (trade name: Nalstar SR-152, manufactured by Nippon A & L, non-volatile (Minute: 48%, average particle size: 180 nm) 25 parts by mass and 15 parts by mass of ion-exchanged water were weighed and kneaded for 1 hour using a sand mill, followed by filtration and vacuum defoaming to obtain a separator material.
The obtained separator material was coated on a hydrophilized olefin-based nonwoven fabric (manufactured by Japan Vilene Co., Ltd., thickness: 90 μm) with a comma coater so that the coating amount (when dried) was 130 g / m ^2. After the construction and drying, heat treatment was further performed at 100 ° C. for 30 minutes to obtain a laminate composed of an organic polymer / inorganic compound-containing separator and a nonwoven fabric.
The obtained laminate had a film thickness of 146 μm and a resistance value of 1.4 Ω · cm ² .

[Example 7]
An organic polymer was prepared in the same manner as in Example 6 except that the hydrophilized olefin-based non-woven fabric was changed to a non-woven fabric (trade name: Papillon BFN No. 2, manufactured by Sankisha Co., Ltd., thickness: 92 μm). / The laminated body which consists of an inorganic compound containing separator and a nonwoven fabric was obtained.
The obtained laminate had a film thickness of 139 μm and a resistance value of 1.2 Ω · cm ² .

[Comparative Example 1]
Hydrotalcite (trade name: DHT-6, manufactured by Kyowa Chemical Industry Co., Ltd., average particle size: 360 nm) 50 parts by mass, styrene-butadiene polymer aqueous dispersion (trade name: Nalstar SR-152, manufactured by Nippon A & L, non-volatile) (Minute: 48%, average particle size: 180 nm) 25 parts by mass and 28 parts by mass of ion-exchanged water were weighed and kneaded for 1 hour using a sand mill, followed by filtration and vacuum defoaming to obtain a separator material.
The separator material thus obtained was coated on a silicone-treated surface of a polyethylene terephthalate (PET) film (release film) whose one side was silicone-treated with a comma coater with a coating amount (when dried) of 150 g / m ² . After coating and drying as described above, the obtained coating film was peeled off from the release film, and further heat-treated at 120 ° C. for 20 minutes to obtain an organic polymer / inorganic compound-containing separator.
The obtained organic polymer / inorganic compound-containing separator had a film thickness of 90 μm and a resistance value of 2.5 Ω · cm ² .

The organic polymer / inorganic compound-containing separators of Examples 1 to 7 and Comparative Example 1 described above have a high organic polymer content, are excellent in strength, and have separators that have an electrode that undergoes a change in shape especially with charge / discharge. It is considered that the short circuit between the positive electrode and the negative electrode due to the growth of dendrites can be sufficiently suppressed. Here, since the organic polymer / inorganic compound-containing separators of Examples 1 to 7 contain the specific inorganic compound according to the present invention, the membrane resistance is low, and it is suitable as a separator for electrochemical devices having low internal resistance. It is used for.

Claims (7)

A separator for an electrochemical device comprising an organic polymer and an inorganic compound,
The inorganic compound has an oxide and / or water having a metal element other than Al, Zn, Pb, Sn, Ga, In, and Bi, having a solubility in water at 20 ° C. of 2 × 10 ⁻² g / 100 g or less. Containing oxides,
The separator for an electrochemical element, wherein the content of the organic polymer is 15% by mass or more in 100% by mass of the separator. The separator for an electrochemical element according to claim 1, wherein the content of the organic polymer is 50% by mass or less in 100% by mass of the separator. The separator for an electrochemical element according to claim 1 or 2, wherein the inorganic compound has an average particle size of 0.3 µm or more and 2 µm or less. The said organic polymer contains a conjugated diene type polymer and / or modified polyolefin, The separator for electrochemical elements in any one of Claims 1-3 characterized by the above-mentioned. The laminated body characterized by including the separator for electrochemical elements in any one of Claims 1-4, and a nonwoven fabric and / or a porous membrane. A separator material for an electrochemical device comprising an organic polymer and an inorganic compound,
The inorganic compound has an oxide and / or water having a metal element other than Al, Zn, Pb, Sn, Ga, In, and Bi, having a solubility in water at 20 ° C. of 2 × 10 ⁻² g / 100 g or less. Containing oxides,
Content of this organic polymer is 15 mass% or more in solid content mass 100 mass% of separator material, The separator material for electrochemical elements characterized by the above-mentioned. An electrochemical device comprising the separator for an electrochemical device according to claim 1 or the laminate according to claim 5.