JP2021136232A - Mixed layer for electrode, electrode, and electrochemical element - Google Patents

Abstract

To provide a mixed layer for an electrode that can achieve both safety and output of an electrochemical element.SOLUTION: A mixed layer for an electrode is formed on an electrode base through an electrode mixture layer and contains an ion-conductive resin and insulating inorganic particles.SELECTED DRAWING: Figure 1

Description

The present invention relates to a mixed layer for electrodes, an electrode, and an electrochemical device.

In recent years, the energy density of energy storage elements such as lithium ion secondary batteries and electrochemical elements such as power generation elements such as fuel cells has been rapidly increasing. An electrochemical element having a high energy density is in an abnormal state such as bursting or ignition due to a foreign substance being mixed in or an impact from the outside. Therefore, it is desired to ensure the safety of the electrochemical element.

In the electrodes used for electrochemical elements, an electrode mixture layer is formed on the electrode substrate, but the cause of the abnormal state of rupture or ignition is that Joule heat generation is generated by an internal short circuit or an external short circuit. Starting from this, the materials that make up the electrochemical element react continuously, causing ignition or thermal runaway.

Patent Document 1 discloses a sheet-type electrode for a secondary battery in which a porous layer containing an inorganic particle and a binder polymer is formed on an electrode active material layer.

However, since the polymer binder has no ion permeability, there is a concern that the ionic conductivity of the porous layer is lowered and the output of the electrochemical device is lowered.

An object of the present invention is to provide a mixed layer for electrodes capable of achieving both safety of an electrochemical device and output.

One aspect of the present invention is an electrode mixed layer formed on an electrode substrate via an electrode mixture layer and containing an ionic conductive resin and insulating inorganic particles.

According to the present invention, it is possible to provide a mixed layer for electrodes capable of achieving both safety of an electrochemical device and output.

It is a figure which shows an example of the negative electrode of this embodiment. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which shows an example of the positive electrode of this embodiment. It is sectional drawing which follows the line BB of FIG. It is sectional drawing which shows an example of the electrode element of this embodiment. It is sectional drawing which shows an example of the electrochemical element of this embodiment. It is a graph which shows the relationship between the charge rate and the output of the non-aqueous power storage element of Example 25 and Comparative Example 9.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The same components may be designated by the same reference numerals and description thereof may be omitted.

<Electrode>
FIG. 1 shows an example of the negative electrode of the present embodiment, and FIG. 2 is a cross-sectional view taken along the line AA of FIG.

In the negative electrode 10, a negative electrode mixture layer 12 and a mixed layer 13 are sequentially formed on the negative electrode substrate 11. Here, the mixed layer 13 contains insulating inorganic particles and an ionic conductive resin. The negative electrode 10 is an example of the electrode of this embodiment.

The shape of the negative electrode 10 is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a flat plate shape.

FIG. 3 shows an example of the positive electrode of the present embodiment, and FIG. 4 is a cross-sectional view taken along the line BB of FIG.

In the positive electrode 20, a positive electrode mixture layer 22 is formed on the positive electrode substrate 21.

Instead of forming the mixed layer 13 on the negative electrode mixture layer 12, the mixed layer 13 is formed on the negative electrode mixture layer 12 and the mixed layer is formed on the positive electrode mixture layer 22. You may.

The shape of the positive electrode 20 is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a flat plate shape.

<< Electrode substrate >>
The material constituting the negative electrode substrate 11 is not particularly limited as long as it is a conductive material, and can be appropriately selected depending on the intended purpose. Examples thereof include stainless steel, nickel, aluminum, and copper. Of these, stainless steel and copper are particularly preferable.

The shape of the negative electrode substrate 11 is not particularly limited and may be appropriately selected depending on the intended purpose.

The size of the negative electrode substrate 11 is not particularly limited as long as it can be applied to an electrochemical element (for example, the electrochemical element 1 shown in FIG. 6), and can be appropriately selected depending on the intended purpose.

The material constituting the positive electrode substrate 21 is not particularly limited as long as it is a conductive material, and can be appropriately selected depending on the intended purpose. Examples thereof include stainless steel, nickel, aluminum, copper, titanium, and tantalum. Be done. Among these, stainless steel and aluminum are particularly preferable.

The shape of the positive electrode substrate 21 is not particularly limited and may be appropriately selected depending on the intended purpose.

The size of the positive electrode substrate 21 is not particularly limited as long as it can be applied to an electrochemical device, and can be appropriately selected depending on the intended purpose.

<< Electrode mixture layer >>
The electrode mixture layer is composed of a negative electrode mixture layer 12 and a positive electrode mixture layer 22. The electrode mixture layer contains an active material (negative electrode active material or positive electrode active material), and may further contain a binder (binding agent), a thickener, a conductive agent, and the like, if necessary.

The negative electrode mixture layer 12 contains a negative electrode active material, and if necessary, a slurry-like liquid composition for a negative electrode mixture layer further containing a binder, a thickener, a conductive agent, a solvent, and the like is placed on the negative electrode substrate 11. It can be formed by coating.

The method for applying the liquid composition for the negative electrode mixture layer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a die coating method, a comma coating method, a gravure coating method, a screen printing method, or a dry method can be used. Examples include a press coating method, a dispenser method, and a liquid discharge method. Among these, the liquid discharge method is preferable.

The positive electrode mixture layer 22 can also be formed in the same manner as the negative electrode mixture layer 12.

The average thickness of the negative electrode mixture layer 12 is preferably 10 to 450 μm, more preferably 20 to 100 μm. When the average thickness of the negative electrode mixture layer 12 is 10 μm or more, the energy density of the electrochemical element is improved, and when it is 450 μm or less, the cycle characteristics of the electrochemical element are improved.

The average thickness of the positive electrode mixture layer 22 is preferably 10 to 300 μm, more preferably 40 to 150 μm. When the average thickness of the positive electrode mixture layer 22 is 10 μm or more, the energy density of the electrochemical element is improved, and when it is 300 μm or less, the output of the electrochemical element is improved.

The negative electrode active material is not particularly limited as long as it can reversibly occlude and release alkali metal ions such as lithium ions, and examples thereof include carbonaceous materials.

Examples of the carbonaceous material include graphite (graphite) such as coke, artificial graphite, and natural graphite, pyrolyzed products of organic substances under various pyrolysis conditions, amorphous carbon, and the like. Among these, artificial graphite, natural graphite, and amorphous carbon are particularly preferable.

The positive electrode active material is not particularly limited as long as it can occlude and release alkali metal ions such as lithium ions reversibly, and examples thereof include alkali metal-containing transition metal compounds.

The alkali metal-containing transition metal compounds, for example, the general formula LiNi _x Co _y Mn _z O ₂
(In the formula, x + y + z = 1.)
In Lithium Ni composite oxide represented by the general formula _{Li x Me y (PO 4)} z
(In the formula, Me is a transition metal, 0.5 ≦ x ≦ 4, 0.5 ≦ y ≦ 2.5, 0.5 ≦ z ≦ 3.5).
Examples thereof include lithium phosphoric acid-based materials represented by.

Examples of the lithium nickel composite oxide include LiNi _0.33 Co _0.33 Mn _0.33 O ₂ , LiNi _0.5 Co _0.2 Mn _0.3 O ₂ , and LiNi _0.6 Co _0.2 Mn _{0. .2} O ₂ , LiNi _0.8 Co _0.2 Mn ₀ O _{2 and the} like can be mentioned.

Examples of the lithium phosphoric acid-based material include vanadium lithium phosphate (Li ₃ V ₂ (PO ₄ ) ₃ ), olivine iron (LiFePO ₄ ), olibin manganese (LiMnPO ₄ ), olibin cobalt (LiCoPO ₄ ), and olivin nickel (LiCoPO 4). Examples _{thereof include LiNiPO 4} ) and olivine vanadium (LiVOPO ₄ ).

The lithium phosphoric acid-based material may be doped with a different element.

Examples of the binder include polyvinylidene fluoride (PVDF), PTFE, polyethylene, polypropylene, aramid resin, polyamide, polyimide, polyamideimide, polyacrylic nitrile, polyacrylic acid, polyacrylic acid methyl ester, polyacrylic acid ethyl ester, and poly. Acrylic acid hexyl ester, polymethacrylic acid, polymethacrylic acid methyl ester, polymethacrylic acid ethyl ester, polymethacrylic acid hexyl ester, polyvinylidene acetate, polyvinylpyrrolidone, polyether, polyethersulfone, hexafluoropolypropylene, styrene butadiene rubber (SBR) ), Carboxymethyl cellulose and the like. These binders may be used alone or in combination of two or more.

Examples of binders other than the above include tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoroalkyl vinyl ether, vinylidene fluoride, chlorotrifluoroethylene, ethylene, propylene, pentafluoropropylene, fluoromethyl vinyl ether, and acrylic acid. Examples thereof include polymers of two or more materials selected from the group consisting of hexadiene.

Examples of the thickener include propylene glycol, carboxymethyl cellulose and the like.

Examples of the conductive agent include graphites such as natural graphite and artificial graphite, carbon blacks such as acetylene black, ketjen black, channel black, furnace black, lamp black and thermal black, and conductivity of carbon fibers and metal fibers. Metal powders such as fibers, carbon fluoride powder and aluminum powder, conductive whiskers such as zinc oxide whisker and potassium titanate whisker, conductive metal oxides such as titanium oxide, phenylene derivatives, organic conductive materials such as graphene derivatives, etc. Can be mentioned.

Examples of the solvent include water, alcohol, N-methyl-2-pyrrolidone (NMP), toluene and the like.

As the active material in the fuel cell, for example, a catalyst carrier such as carbon in which catalyst particles such as platinum particles, ruthenium particles, and platinum alloy particles are supported on the surface can be used.

An example of a method for manufacturing electrodes for a fuel cell will be described below.

First, the catalyst carrier is suspended in water, and then the precursor of the catalyst particles is added and dissolved. Next, alkali is added to precipitate metal hydroxide particles and support them on the surface of the catalyst carrier. Next, a liquid composition containing a catalyst carrier supporting metal hydroxide particles on the surface is applied onto an electrode substrate, and then the metal hydroxide is reduced under a hydrogen atmosphere or the like to produce a catalyst. Particles are generated and an electrode mixture layer is formed.

Examples of the precursors of the catalyst particles include chloroplatinic acid, dinitrodiaminoplatinum, secondary platinum chloride, primary platinum chloride, bisacetylacetonate platinum, dichlorodiammine platinum, dichlorotetramine platinum, and second platinum sulfate ruthenic acid. Examples thereof include iridium chloride, rhodium chloride, ferric chloride, cobalt chloride, chromium chloride, gold chloride, silver nitrate, rhodium nitrate, palladium chloride, nickel nitrate, iron sulfate and copper chloride.

Examples of active materials in solar cells include oxide semiconductors such _{as SnO 2} , ZnO, ZrO ₂ , Nb ₂ O ₅ , CeO ₂ , SiO ₂ , and Al ₂ O ₃ , in addition to tungsten oxide and titanium oxide.

Here, the oxide semiconductor carries a dye.

Examples of the dye include a ruthenium-tris type transition metal complex, a ruthenium-bis type transition metal complex, an osmium-tris type transition metal complex, an osmium-bis type transition metal complex, and a ruthenium-cis-diaqua-bipyridyl complex. , Phtalocyanin and porphyrin, organic-inorganic perovskite crystals and the like.

In the following description, as an example, a case where the alkali metal ion is a lithium ion will be described.

<< Mixed layer >>
The mixed layer 13 is formed on the electrode substrate via the electrode mixture layer. In the present embodiment, as described above, the mixed layer 13 is formed on the negative electrode substrate 11 via the negative electrode mixture layer 12. The mixed layer 13 contains insulating inorganic particles and an ionic conductive resin. The mixed layer 13 is an example of the mixed layer for electrodes of the present embodiment.

The mass ratio of the ionic conductive resin to the insulating inorganic particles in the mixed layer 13 is preferably 0.5 to 50%, more preferably 0.5 to 20%. When the mass ratio of the ionic conductive resin to the insulating inorganic particles in the mixed layer 13 is 0.5% or more, the peel strength of the mixed layer 13 is improved, and when it is 20% or less, the output of the electrochemical element is output. improves.

The thickness of the mixed layer 13 is preferably 1 to 30 μm, more preferably 2 to 20 μm. When the thickness of the mixed layer 13 is 1 μm or more, the safety of the electrochemical element is improved, and when it is 30 μm or less, the output of the electrochemical element is improved.

<<< Insulating Inorganic Particles >>>
Examples of the material constituting the insulating inorganic particles include metal oxides, metal nitrides, and other metal compounds.

Examples of the metal oxide include Al ₂ O ₃ , TiO ₂ , BaTiO ₃ , ZrO _{2, and the} like.

Examples of the metal nitride include aluminum nitride and silicon nitride.

Other metal compounds include, for example, sparingly soluble ionic crystals such as aluminum fluoride, calcium fluoride, barium fluoride, barium sulfate, boehmite, zeolite, apatite, kaolin, mulite, spinel, olivine, sericite, bentonite and the like. Mineral resource-derived substances or their man-made products can be mentioned.

Examples of the material constituting the insulating inorganic particles other than the above include glass ceramics.

The glass ceramic, for example, crystallized glass ceramics using crystallized glass of _{ZnO-MgO-Al 2 O 3} -SiO 2 _{system, BaO-Al 2 O 3 -SiO} 2 based _ceramic, Al ₂ O 3 -CaO- Examples thereof include non-glass ceramics using SiO _2- MgO-B ₂ O _{3 ceramics and the like.}

The insulating inorganic particles preferably contain an element having ionic conductivity.

Examples of the element having ionic conductivity include a silicon element, an aluminum element, a zirconium element and the like. These ionic conductive elements may be used alone or in combination of two or more.

The insulating inorganic particles _{are preferably Al 2} O ₃ (alumina) particles. As a result, the mixed layer 13 having high insulation and high heat resistance can be formed at low cost.

Among the alumina, it is preferable to use α-alumina, which has a high melting point and is thermally stable, as the insulating inorganic particles. Examples of such α-alumina include AES-11C (manufactured by Sumitomo Chemical Co., Ltd.), AES-11F (manufactured by Sumitomo Chemical Co., Ltd.), CT3000 (manufactured by Armatis Co., Ltd.), LS-711CB (Nippon Light Metal), and LS-502. (Nippon Light Metal Co., Ltd.), SLS-710 (Nippon Light Metal Co., Ltd.), SEPal-60 (manufactured by Arteo Co., Ltd.), SEPal-70 (manufactured by Arteo Co., Ltd.) and the like. These α-alumina may be used alone or in combination of two or more. These α-alumina have high electrical insulation resistance and are suitable as the material for the electrode of the present embodiment.

By using the insulating inorganic particles, it is possible to suppress an internal short circuit of the electrochemical element and improve the safety of the electrochemical element. Further, since the surface of the insulating inorganic particles has ionic conductivity, the ionic conductivity of the mixed layer 13 can be improved. This improves the output of the electrochemical device.

The average particle size of the insulating inorganic particles is preferably 0.1 to 5 μm, more preferably 0.1 to 3 μm. As a result, the surface area of the insulating inorganic particles is increased, and the ionic conductivity of the mixed layer 13 can be improved even when the amount of the insulating inorganic particles used is small.

The average particle size of the insulating inorganic particles can be measured by a laser diffraction method.

The mixed layer 13 is formed by binding insulating inorganic particles with an ionic conductive resin produced by thermosetting or photocuring a liquid composition containing an ethylenically unsaturated compound and insulating inorganic particles. Can be done. As a result, the peel strength of the mixed layer 13 is improved.

The mass ratio of the ethylenically unsaturated compound to the insulating inorganic particles in the liquid composition is preferably 0.5 to 50%, more preferably 0.5 to 20%. When the mass ratio of the ethylenically unsaturated compound to the insulating inorganic particles in the mixed layer 13 is 0.5% or more, the peel strength of the mixed layer 13 is improved, and when it is 20% or less, the output of the electrochemical element is obtained. Is improved.

<<< Ethylene unsaturated compound >>>
Examples of the ethylenically unsaturated compound include a monomer having one or more ethylenically unsaturated bonds, an oligomer and the like.

Here, since the ethylenically unsaturated bond is a radically polymerizable functional group, the group other than the radically polymerizable functional group of the ethylenically unsaturated compound usually also has an ionic conductive resin.

Ethylene unsaturated compounds are represented by the general formula (I).

（式中、Ｘは、アルキル基、ハロゲン原子、シアノ基、ニトロ基又はアルコキシ基であり、Ｒは、ハロゲン原子を含む基、リン酸エステル結合を含む基、ホスホン酸基を含む基、−ＣＯ−基を含む基、−ＣＯＯ−基を含む基、−ＣＯＮ−基を含む基又は−Ｓ−基を含む基である。）
で表される化合物であることが好ましい。

(In the formula, X is an alkyl group, a halogen atom, a cyano group, a nitro group or an alkoxy group, and R is a group containing a halogen atom, a group containing a phosphate ester bond, a group containing a phosphonic acid group, -CO. A group containing a-group, a group containing a -COO- group, a group containing a -CON- group, or a group containing a -S- group.)
It is preferably a compound represented by.

Examples of the alkyl group in X include a methyl group and an ethyl group.

Examples of the alkoxy group in X include a methoxy group and an ethoxy group.

The radically polymerizable functional group preferably has an acryloyloxy group or a methacryloyloxy group.

The ethylenically unsaturated compound preferably has a halogen atom from the viewpoint of improving the lithium ion conductivity of the mixed layer 13. Further, the ethylenically unsaturated compound may be a monomer having a carboxyl group or a phosphonic acid group, a phosphoric acid ester monomer, or a radically polymerizable oligomer from the viewpoint of adhesion to the insulating inorganic particles contained in the mixed layer 13. preferable.

Examples of the ethylenically unsaturated compound having a fluorine atom include heptadecafluorodecyl acrylate, octafluoropentyl acrylate, 2-perfluorooctyl ethyl acrylate, 2-perfluorooctyl ethyl methacrylate, and 2-perfluoroisononyl ethyl acrylate. Can be mentioned.

Examples of the ethylenically unsaturated compound having a carboxyl group include a chemical formula.

で表される化合物が挙げられる。

Examples thereof include compounds represented by.

Examples of the ethylenically unsaturated compound having a phosphonic acid group include a chemical formula.

で表される化合物が挙げられる。

Examples thereof include compounds represented by.

As the phosphoric acid ester monomer, for example, a chemical formula

で表される化合物が挙げられる。

Examples thereof include compounds represented by.

Examples of the radically polymerizable oligomer include epoxy acrylate-based oligomers, urethane acrylate-based oligomers, polyester acrylate-based oligomers, and the like.

Ethylene unsaturated compounds are represented by the general formula (II).

（式中、Ｘ_２は、水素原子又はメチル基であり、ｎは、１〜２４である。）
で表される基を有することが特に好ましい。

(In the formula, X ₂ is a hydrogen atom or a methyl group, and n is 1 to 24.)
It is particularly preferable to have a group represented by.

Here, when X ₂ is a hydrogen atom, a resin having an oxyethylene group is produced as an ionic conductive resin.

Examples of the ethylenically unsaturated compound having a group represented by the general formula (II) include a monofunctional radical polymerizable compound having 1 polymerizable functional group and a bifunctional radical polymerizable compound having 2 polymerizable functional groups. Examples thereof include compounds, radically polymerizable compounds having three or more functional groups and three or more polymerizable functional groups.

Examples of the monofunctional radically polymerizable compound include methoxypolyethylene glycol monoacrylate, methoxypolyethylene glycol monomethacrylate, and chemical formula.

で表される化合物等が挙げられる。

Examples thereof include compounds represented by.

Examples of the bifunctional radically polymerizable compound include polyethylene glycol diacrylate, neopentyl glycol diacrylate, dioxane glycol diacrylate, and chemical formula.

で表される化合物等が挙げられる。

Examples thereof include compounds represented by.

Examples of the trifunctional or higher functional radical polymerizable compound include glycerin triacrylate ethoxylated, glycerin triacrylate propoxylated, trimethylol propanetriacrylate, trimethylol ethoxylated propanetriacrylate, propoxylated trimethylol propanetriacrylate, and pentaerythritol tetra. Acrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated pentaerythritol tetraacrylate, dipentaerythritol polyacrylate, ethoxylated dipentaerythritol polyacrylate, propoxylated dipentaerythritol polyacrylate, ethoxylated polyglycerin acrylate, dendric polymer acrylate, chemical formula

で表される化合物、例えば、化学式

Compound represented by, for example, chemical formula

で表される化合物等が挙げられる。

Examples thereof include compounds represented by.

The ethylenically unsaturated compound may be used alone or in combination of two or more.

<< Lithium salt >>
The mixed layer 13 preferably further contains a lithium salt. This improves the ionic conductivity of the mixed layer 13.

Examples of the lithium salt include lithium bis (fluorosulfonyl) imide (LiFSI), lithium bis (trifluoromethanesulfonyl) imide (LiTFSI), lithium hexafluorophosphate (LiPF ₆ ), lithium perchlorate (LiClO ₄ ), and chloride. Lithium (LiCl), Lithium borofluoride (LiBF ₄ ), Lithium hexafluorophosphate (LiAsF ₆ ), Lithium trifluoromethsulfonate (LiCF ₃ SO ₃ ), Lithimbistrifluoromethylsulfonylimide (LiN (C ₂ F)) Examples thereof include ₅ SO ₂ ) ₂ ) and lithium bispherfluoroethyl sulfonylimide (LiN (CF ₂ F ₅ SO ₂ ) _2). These lithium salts may be used alone or in combination of two or more. Among these, LiTFSI and LiFSI are particularly preferable from the viewpoint of low deliquescent property.

When forming the mixed layer 13 containing a lithium salt, from the viewpoint of ionic conductivity of the mixed layer 13, a liquid composition containing an ethylenically unsaturated compound, insulating inorganic particles, a lithium salt, and a diluting solvent is used. It is preferable to use it.

<< Diluting solvent >>
The diluting solvent is not particularly limited as long as it can reduce the viscosity of the ethylenically unsaturated compound, and can be appropriately selected depending on the intended purpose. For example, alcohols such as methanol, ethanol, propanol and butanol can be selected. Solvents; Ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; Estel solvents such as ethyl acetate and butyl acetate; Ether solvents such as tetrahydrofuran, dioxane and propyl ether; Halogen-based solvents; aromatic solvents such as benzene, toluene, and xylene; cellosolve-based solvents such as methyl cellosolve, ethyl cellosolve, and cellosolve acetate can be mentioned. These diluting solvents may be used alone or in combination of two or more. Among these, carbonate-based organic solvents such as chain carbonate and cyclic carbonate are preferable from the viewpoint of dissolving the lithium salt at room temperature.

Examples of the chain carbonate include dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC), methyl propionate (MP) and the like.

Examples of the cyclic carbonate include propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), vinylene carbonate (VC) and the like.

When ethylene carbonate (EC) as a cyclic carbonate and dimethyl carbonate (DMC) as a chain carbonate are used in combination, the mixing ratio of ethylene carbonate (EC) and dimethyl carbonate (DMC) is particularly high. There is no limitation, and it can be appropriately selected according to the purpose.

<< Method of forming mixed layer >>
As a method for forming the mixed layer 13, for example, a liquid composition containing a precursor of an ionic conductive resin (ethylene unsaturated compound) and insulating inorganic particles is applied onto the negative electrode mixture layer 12, and then a liquid is formed. Examples thereof include a method of heat-curing or photo-curing the composition.

The method for applying the liquid composition is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a die coating method, a comma coating method, a gravure coating method, a screen printing method, a dry press coating method, or a dispenser. Examples include the method and the liquid discharge method. Among these, the liquid discharge method is preferable.

The liquid composition may further contain a dispersant, a thickener and the like, if necessary.

Commercially available dispersants include, for example, Megafuck (registered trademark) F444 (manufactured by DIC), Marialim (registered trademark) HKM-150A, SC-0708A (all manufactured by NOF Corporation), and Disper BYK103 (manufactured by NOF CORPORATION). ) Etc. can be mentioned.

Examples of the thickener include propylene glycol, carboxymethyl cellulose and the like.

Examples of the method of curing the liquid composition include a method of heating the liquid composition in a vacuum dryer.

The liquid composition may further contain a polymerization inhibitor in order to prevent the precursor of the ionic conductive resin from being polymerized and cured by light, heat, air or the like during storage.

When the liquid composition is cured, it is preferable to raise the temperature to 100 ° C. or higher. As a result, it can also serve as a dehydration step. In addition, the polymerization inhibitor is also discharged to the outside of the system or thermally decomposed, so that the thermal polymerization of the precursor of the ionic conductive resin is promoted.

When the liquid composition is cured, the temperature is preferably raised to 60 to 150 ° C., and more preferably 60 to 150 ° C. under reduced pressure, from the viewpoint of drying the liquid composition.

When the liquid composition is cured, the ethylenically unsaturated compound is radically polymerized to produce an ionic conductive resin, but the curing process uses the absorption peak derived from the ethylenically unsaturated bond in the infrared absorption spectrum. , Can be analyzed. For example, CH surfaces of C = C stretching vibration band, CH plane target bending vibration band B region (1430~1400cm ^-1) of the A region (1640~1620cm ^-1), C region (820~800cm ^-1) From the attenuation of the externally variable angular vibration band, it is possible to confirm the degree of polymerization progress and the presence or absence of a residue of the ethylenically unsaturated compound. In the infrared absorption spectrum of the liquid composition before curing, absorption peaks derived from ethylenically unsaturated compounds are present in the A region, B region, and C region. As the polymerization progresses, the absorption peak derived from the ethylenically unsaturated compound decreases. Then, when all the ethylenically unsaturated compounds are converted into the ionic conductive resin, the absorption peak derived from the ethylenically unsaturated compounds disappears.

When the liquid composition is cured, a polymerization initiator may be added to the liquid composition to apply energy from the outside.

Examples of the external energy include heat, light, radiation and the like.

As a method for heating the liquid composition, for example, hot air of an inert gas such as air or nitrogen, various heat media, infrared rays, or electromagnetic waves are used to discharge the liquid composition, or the side of the negative electrode substrate 11. Therefore, a method of heating and the like can be mentioned.

Examples of the method of irradiating the liquid composition with light include a method of irradiating ultraviolet rays using an ultraviolet irradiation light source such as a high-pressure mercury lamp and a metal halide lamp, and a method of irradiating visible light using a visible light light source.

The amount of ultraviolet light irradiated is preferably 5 to ^{15,000 mW / cm 2.}

<< Polymerization inhibitor >>
Examples of the polymerization inhibitor include tetrabutylhydroquinone, 4-tetrautylpicatechol, dibutylhydroxytoluene, 1,1-diphenyl-2-picrylhydroradical, hydroquinone, phenothiazine and the like. Among these, 1,4-benzoquinone, hydroquinone, and metoshiki hydroquinone are particularly preferable because they have sublimation properties.

The mass ratio of the polymerization inhibitor to the ethylenically unsaturated compound is usually 1 to 5000 ppm, preferably 5 to 5000 ppm, and more preferably 10 to 500 ppm.

<< Polymerization Initiator >>
Examples of the polymerization initiator include a thermal polymerization initiator and a photopolymerization initiator. These polymerization initiators may be used alone or in combination of two or more.

The thermal polymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 2,5-dimethylhexane-2,5-dihydroperoxide, dicumyl peroxide, benzoyl peroxide, etc. t-butylcumyl peroxide, 2,5-dimethyl-2,5-di (peroxybenzoyl) hexin-3, di-t-butylbeloxide, t-butylhydrobeloxide, cumenehydrobeloxide, lauroyl peroxide Peroxide-based initiators such as azobisisobutylnitrile, azobiscyclohexanecarbonitrile, methyl azobisisobutyrate, azobisisobutylamidine hydrochloride, azo-based initiators such as 4,4'-azobis-4-cyanovaleric acid, etc. Can be mentioned.

The photopolymerization initiator is not particularly limited and may be appropriately selected depending on the intended purpose. For example, diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy -Cyclohexyl-phenyl-ketone, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1, 2-Hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-2-morpholino (4-methylthiophenyl) propan-1-one, 1-phenyl-1,2-propanedione-2- ( Acetphenone-based or ketal-based photopolymerization initiators such as o-ethoxycarbonyl) oxime; benzophenone-based photopolymerization initiators such as benzophenone, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether, benzoin isopropyl ether; benzophenone, 4-hydroxy Benzophenone-based photopolymerization initiators such as benzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylicized benzophenone, 1,4-benzoylbenzene; 2-isopropylthioxanthone, 2 Examples thereof include thioxanthone-based photopolymerization initiators such as −chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, and 2,4-dichlorothioxanthone.

Examples of photopolymerization initiators other than the above include ethylanthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, and bis (2,4,6-trimethylbenzoyl). ) Phenylphosphine oxide, bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglioxyester, 9,10-phenanthrene, aclysine compounds, triazine compounds, imidazole compounds, And so on.

A photopolymerization initiator and a photopolymerization accelerator may be used in combination.

Examples of the photopolymerization accelerator include triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, ethyl benzoate (2-dimethylamino), and 4,4'-dimethylaminobenzophenone. And so on.

The mass ratio of the polymerization initiator to the ethylenically unsaturated compound is preferably 0.5 to 40%, more preferably 1 to 20%.

<Electrode element>
FIG. 5 shows an example of the electrode element of this embodiment.

In the electrode element 40, the negative electrode 17 and the positive electrode 27 are laminated in a state of being insulated from each other via the separator 30. Here, the positive electrode 27 is formed on both sides of the negative electrode 17. Further, a lead wire 41 is connected to the negative electrode base 11, and a lead wire 42 is connected to the positive electrode base 21.

The negative electrode 17 is the same as the negative electrode 10 except that the negative electrode mixture layer 12 and the mixed layer 13 are sequentially formed on both surfaces of the negative electrode substrate 11.

The positive electrode 27 is the same as the positive electrode 20 except that the positive electrode mixture layers 22 are formed on both sides of the positive electrode substrate 21.

The number of layers of the negative electrode 17 and the positive electrode 27 in the electrode element 40 is not particularly limited.

Further, the number of negative electrodes 17 and the number of positive electrodes 27 may be the same or different.

<Electrochemical element>
FIG. 6 shows an example of the electrochemical device of the present embodiment. The electrochemical element 1 shown in FIG. 6 has the above-mentioned electrodes (negative electrode 10 and positive electrode 20). Specifically, the electrochemical element 1 includes the electrode element 40 shown in FIG.

In the electrochemical element 1, an electrolyte layer 51 composed of an aqueous electrolyte solution or a non-aqueous electrolyte is formed on the electrode element 40, and is sealed by an exterior 52. In the electrochemical element 1, the lead wires 41 and 42 are led out to the outside of the exterior 52.

The electrochemical element 1 may have other members, if necessary.

The electrochemical element 1 is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a non-aqueous secondary battery, a non-aqueous capacitor and other storage elements.

The shape of the electrochemical element 1 is not particularly limited, and for example, a laminated type, a cylinder type in which a sheet electrode and a separator are spirally formed, a cylinder type having an inside-out structure in which a pellet electrode and a separator are combined, a pellet electrode and a separator are used. Examples include stacked coin types.

Examples of the electrochemical element 1 include an aqueous power storage element, a non-aqueous power storage element, and the like.

<Separator>
The separator 30 is provided between the negative electrode 17 and the positive electrode 27, if necessary, in order to prevent a short circuit between the negative electrode 17 and the positive electrode 27.

The separator 30 has ion permeability and no electron conductivity.

The material, shape, size, and structure of the separator 30 are not particularly limited and may be appropriately selected depending on the intended purpose.

Examples of the separator 30 include paper such as kraft paper, vinylon mixed paper, synthetic pulp mixed paper, polyolefin non-woven fabric such as cellophane, polyethylene graft film, polypropylene melt flow non-woven fabric, polyamide non-woven fabric, glass fiber non-woven fabric, and polyethylene-based microporous film. Examples thereof include polypropylene-based microporous membranes.

The porosity of the separator 30 is preferably 50% or more from the viewpoint of retaining the non-aqueous electrolytic solution.

The average thickness of the separator 30 is preferably 3 to 50 μm, more preferably 5 to 30 μm.

Examples of the shape of the separator 30 include a sheet shape and the like.

The size of the separator 30 is not particularly limited as long as it can be applied to the electrochemical element 1, and can be appropriately selected depending on the intended purpose.

The separator 30 may have a single-layer structure or a laminated structure.

When a solid electrolyte is used as the non-aqueous electrolyte, the separator 30 can be omitted.

<Electrolyte aqueous solution>
Examples of the electrolyte salt constituting the electrolyte aqueous solution include sodium hydroxide, potassium hydroxide, sodium chloride, potassium chloride, ammonium chloride, zinc chloride, zinc acetate, zinc bromide, zinc iodide, zinc tartrate, zinc perchloride and the like. Be done.

<Non-aqueous electrolyte>
As the non-aqueous electrolyte, a solid electrolyte or a non-aqueous electrolyte solution can be used.

Here, the non-aqueous electrolytic solution is an electrolytic solution in which an electrolyte salt is dissolved in a non-aqueous solvent.

<Non-aqueous solvent>
The non-aqueous solvent is not particularly limited, and for example, an aprotic organic solvent is preferably used.

As the aprotic organic solvent, a carbonate-based organic solvent such as a chain carbonate or a cyclic carbonate can be used.

Examples of the chain carbonate include dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (EMC) and the like.

Examples of the cyclic carbonate include propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), vinylene carbonate (VC) and the like.

As the non-aqueous solvent other than the carbonate-based organic solvent, for example, an ester-based organic solvent such as a cyclic ester or a chain ester, an ether-based organic solvent such as a cyclic ether or a chain ether, or the like can be used.

Examples of the cyclic ester include γ-butyrolactone (γBL), 2-methyl-γ-butyrolactone, acetyl-γ-butyrolactone, γ-valerolactone and the like.

Examples of the chain ester include propionic acid alkyl ester, malonic acid dialkyl ester, acetate alkyl ester (for example, methyl acetate (MA) and ethyl acetate), formic acid alkyl ester (for example, methyl formate (MF) and ethyl formate) and the like. Can be mentioned.

Examples of the cyclic ether include tetrahydrofuran, alkyl tetrahydrofuran, alkoxytetrahydrofuran, dialkoxytetrahydrofuran, 1,3-dioxolane, alkyl-1,3-dioxolane, 1,4-dioxolane and the like.

Examples of the chain ether include 1,2-dimethosicietan (DME), diethyl ether, ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, triethylene glycol dialkyl ether, tetraethylene glycol dialkyl ether and the like.

<Electrolyte salt>
As the electrolyte salt, a lithium salt can be used.

The lithium salt is not particularly limited and may be appropriately selected depending on the intended purpose. For example, lithium hexafluorophosphate (LiPF ₆ ), lithium perchlorate (LiClO ₄ ), lithium chloride (LiCl), and phosphite. Lithium chloride (LiBF ₄ ), Lithium hexafluorophosphate (LiAsF ₆ ), Lithium trifluoromethsulfonate (LiCF ₃ SO ₃ ), Lithimbistrifluoromethylsulfonylimide (LiN (C ₂ F ₅ SO ₂ ) ₂ ), Examples thereof include lithium bispherfluoroethylsulfonylimide (LiN (CF ₂ F ₅ SO ₂ ) _2). These lithium salts may be used alone or in combination of two or more. _{Among these, LiPF 6} is particularly preferable from the viewpoint of the large amount of anions occluded into the carbon electrode.

The concentration of the electrolyte salt in the non-aqueous electrolyte solution is preferably 0.7 to 4 mol / L, more preferably 1.0 to 3 mol / L, and 1.0 to 2.5 mol / L. Is even more preferable.

<Use of electrochemical devices>
The use of the electrochemical element is not particularly limited, and for example, a laptop computer, a pen input personal computer, a mobile personal computer, an electronic book player, a mobile phone, a mobile fax, a mobile copy, a mobile printer, a headphone stereo, a video movie, an LCD TV, etc. Handy cleaners, portable CDs, mini disks, transceivers, electronic notebooks, calculators, memory cards, portable tape recorders, radios, backup power supplies, motors, lighting equipment, toys, game machines, watches, strobes, cameras, etc.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to the examples. Unless otherwise specified, "parts" and "%" are based on mass.

<Ethylene unsaturated monomer (preparation of monomer solution)>
As a polymerization inhibitor, 100 ppm of methoxyhydroquinone was dissolved in each of the four types of monomers (Compounds 1 to 4) having an ethylenically unsaturated bond shown in Table 1. All of these monomers having an ethylenically unsaturated bond have an oxyethylene group. In addition, these monomers can be polymerized to form a resin having an oxyethylene group.

Next, the compounds 1 to 4 shown in Table 1 were mixed at the weighing values shown in Table 2 to prepare a monomer liquid (monomer liquids 1 to 4).

<Preparation of mixed solution>
[Mixed solution 1]
As shown in Table 3, a solution in which 30 wt% of lithium bis (fluorosulfonyl) imide (LiFSI) as a Li salt is dissolved in a mixed solution of dimethyl carbonate (DMC): ethylene carbonate (EC) = 2: 1 (hereinafter, ω). Liquid) was prepared. The mixed liquid 1 was prepared by mixing the monomer liquids (monomer liquids 1 to 4) and the ω liquid shown in Table 2 with the blending amounts shown in Tables 4 and 5.

[Mixed solution 2]
A solution without using a Li salt (hereinafter referred to as α solution) was prepared in a mixed solution of dimethyl carbonate (DMC): ethylene carbonate (EC) = 2: 1. The mixed liquid 2 was prepared by mixing the α liquid with the monomer liquids (monomer liquids 1 to 4) shown in Table 2 in the blending amounts shown in Tables 6 and 7.

[Peel strength]
Peel strength (based on JIS Z 0237: 2009) is measured with an adhesive / film peeling analyzer (VPA (Versail Peel Analyzer) manufactured by Kyowa Interface Science Co., Ltd.), and the adhesion of the mixed layer to the substrate is evaluated according to the following criteria. bottom.
A: Peel strength is 30 N / m or more (adhesion is good)
B: Peel strength is 1 N / m or more and less than 30 N / m (adhesion is acceptable in actual use)
C: Peel strength is less than 1 N / m (adhesion is poor)

[Example 1]
100 g of the mixed solution 1 was weighed, and 3.0 g of AIBN (2,2'-azobisisobutyronitrile manufactured by Tokyo Kasei Co., Ltd.) was dissolved as a polymerization initiator.

Next, 100 g of CT3000 (manufactured by Armatis) and 5 g of Marialim (registered trademark) SC-0708A (manufactured by NOF) as alumina fine particles and 140 g of methyl ethyl ketone as a solvent were mixed and dispersed with a homogenizer Gsmasher (manufactured by Rix). A dispersion having a solid content concentration of 40 wt% of the alumina particles CT3000 was prepared.

To 100 g of this alumina dispersion, 4 g of a mixture 1 in which a polymerization initiator was dissolved was added, and the mixture was stirred with a magnetic stirrer. The mixed solution 1 in which this alumina was dispersed was coated on an aluminum foil base material using a doctor blade film applicator (coating width 50 mm, gap 75 um manufactured by Allgood Co., Ltd.). This substrate was placed in a vacuum drier and dried at 80 ° C. for 6 hours, followed by drying at 120 ° C. for 6 hours. This was cooled to room temperature to obtain a test piece in which a mixed layer was formed on a substrate. The adhesion of the mixed layer was evaluated for the obtained test piece. The evaluation results are shown in Table 8.

[Example 2]
A test body was prepared and evaluated in the same manner as in Example 1 except that the amount of the mixed solution 1 in which the polymerization initiator was dissolved was 2 g. The evaluation results are shown in Table 8.

[Example 3]
A test piece was prepared and evaluated in the same manner as in Example 1 except that the mixed solution 2 was used instead of the mixed solution 1. The evaluation results are shown in Table 8.

[Examples 4 to 6]
Specimens were prepared and evaluated in the same manner as in Examples 1 to 3 except that LS-711CB (manufactured by Nippon Light Metal Co., Ltd.) was used instead of CT3000 as the alumina fine particles. The evaluation results are shown in Table 8.

[Examples 7 to 9]
Specimens were prepared and evaluated in the same manner as in Examples 1 to 3 except that AES-11C (manufactured by Sumitomo Chemical Co., Ltd.) was used instead of CT3000 as the alumina fine particles. The evaluation results are shown in Table 8.

[Examples 10 to 12]
Specimens were prepared and evaluated in the same manner as in Examples 1 to 3 except that AES-11F (manufactured by Sumitomo Chemical Co., Ltd.) was used instead of CT3000 as the alumina fine particles. The evaluation results are shown in Table 8.

[Examples 13 to 15]
Specimens were prepared and evaluated in the same manner as in Examples 1 to 3 except that LS-502 (manufactured by Nippon Light Metal Co., Ltd.) was used instead of CT3000 as the alumina fine particles. The evaluation results are shown in Table 8.

[Examples 16 to 18]
Specimens were prepared and evaluated in the same manner as in Examples 1 to 3 except that SLS-710 (manufactured by Nippon Light Metal Co., Ltd.) was used instead of CT3000 as the alumina fine particles. The evaluation results are shown in Table 8.

[Examples 19 to 21]
Specimens were prepared and evaluated in the same manner as in Examples 1 to 3 except that SEPal-60 (manufactured by Arteo) was used instead of CT3000 as the alumina fine particles. The evaluation results are shown in Table 8.

[Examples 22 to 24]
Specimens were prepared and evaluated in the same manner as in Examples 1 to 3 except that SEPal-70 (manufactured by Arteo) was used instead of CT3000 as the alumina fine particles. The evaluation results are shown in Table 8.

[Comparative Examples 1 to 8]
Specimens were prepared and evaluated in the same manner as in Examples 1, 4, 7, 10, 13, 16, 19, and 22, except that only the alumina dispersion was used without adding the mixed solution 1. The evaluation results are shown in Table 8.

From Table 8, the monomers shown in Table 1 were mixed in the blending amounts shown in Table 2, and the mixed solution containing the solution containing the Li salt shown in Table 3 was added to the separately prepared alumina dispersion and added to the substrate. The test piece obtained by heating and drying had a peel strength of 30 N / m or more, and the adhesion of the mixed layer was good.

From the evaluation result of this adhesion, it can be seen that the adhesion of the mixed layer containing the alumina fine particles is sufficient, and when it is used for the electrode mixed layer of the present embodiment, the effect of suppressing the peeling of the alumina fine particles can be expected.

Next, the peel strength of the mixed layer of the negative electrode was evaluated.

<Peeling strength of mixed layer>
After the cellophane tape was attached to the surface of the negative electrode, the cellophane tape was peeled off at a peeling angle of 90 °, and the peeling strength of the mixed layer was measured.

The peel strength of the mixed layer was evaluated to be good if it was 30 N / m or more.

[Example 25]
97 parts of the negative electrode active material graphite, 1 part of the thickener carboxymethyl cellulose, 2 parts of the binder resin styrene-butadiene rubber, and 100 parts of water were mixed to obtain a liquid composition for the negative electrode mixture layer.

Using the liquid discharge method, the liquid composition for the negative electrode mixture layer was applied onto the copper foil and then dried to form the negative electrode mixture layer. At this time, a negative electrode mixture layer having a basis weight of 9 mg / cm ^{2 was formed on both sides of the copper foil.}

Alumina particles AKP-3000 (manufactured by Sumitomo Chemical Co., Ltd.) 40 parts, polyfunctional acrylate TA-210 with polyoxyethylene group (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1.2 parts, lithium bis (fluorosulfonyl) imide (LiFSI) 0 .36 parts, mixed solvent of ethylene carbonate and dimethyl carbonate (mass ratio 2: 1) 1.44 parts, ethyl lactate 56.89 parts, photopolymerization initiator Imide® 184 (manufactured by IGM Resins BV) ) 0.108 parts were mixed to obtain a liquid composition for a mixed layer. In addition, 100 ppm of the polymerization inhibitor methoxyhydroquinone was dissolved in TA-210 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) in advance.

After discharging the liquid composition for the mixed layer onto the negative electrode mixture layer using the liquid discharge device EV2500 (manufactured by Ricoh) and the liquid discharge head MH5421F (manufactured by Ricoh), the center wavelength is 365 nm and the illuminance is in a nitrogen gas purge atmosphere. A mixed layer was formed by irradiating with ultraviolet rays of 40 mW / cm ^{2 for 1 minute.} At this time, a mixed layer having a basis weight of 1.0 mg / cm ² (thickness 6 μm) was formed on both sides of the negative electrode mixture layer.

A negative electrode was obtained by punching so that the area where the negative electrode mixture layer and the mixed layer were formed was 30 mm × 50 mm and the area where the negative electrode mixture layer and the mixed layer were not formed was 10 mm × 11 mm. The peel strength of the mixed layer was evaluated for the obtained negative electrode. Table 9 shows the blending amount of each component in the negative electrode, and Table 10 shows the evaluation results.

[Examples 26 to 30]
When preparing a liquid composition for a mixed layer, TA-210 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), LiFSI, mixed solvent, ethyl lactate, Omnirad (registered trademark) 184 (manufactured by IGM Resins BV) are blended. A negative electrode was prepared and evaluated in the same manner as in Example 25, except that the amount was changed as shown in Table 9. Table 9 shows the blending amount of each component in the negative electrode, and Table 10 shows the evaluation results.

[Comparative Example 9]
A negative electrode was prepared and evaluated in the same manner as in Example 25 except that the mixed layer was not formed. The evaluation results are shown in Table 10.

[Comparative Example 10]
40 parts of alumina particles AKP-3000 (manufactured by Sumitomo Chemical Co., Ltd.), 1.2 parts of binder resin AZ-9129 (manufactured by Zeon Corporation), and 58.8 parts of ethyl lactate were mixed to obtain a liquid composition for a mixed layer.

A negative electrode was obtained in the same manner as in Example 25 except that the obtained liquid composition for a mixed layer was used. The evaluation results are shown in Table 10.

Next, the output and safety of the non-aqueous power storage element were evaluated. The negative electrodes of Examples 25 to 30 and Comparative Examples 9 and 10 were applied to the negative electrodes of the non-aqueous power storage elements to be evaluated.

<Preparation of positive electrode>
93 parts of lithium nickel cobalt aluminum composite oxide (NCA), 3 parts of conductive agent acetylene black, 4 parts of binder resin polyvinylidene fluoride, and 100 parts of N-methylpyrrolidone were mixed to obtain a liquid composition for a positive mixture layer. ..

Using the die coating method, the liquid composition for the positive electrode mixture layer was applied onto the aluminum foil at a transport speed of 0.5 m / min and then dried to form the positive electrode mixture layer. At this time, positive electrode mixture layers having a basis weight of 15.0 mg / cm ^{2 were formed on both sides of the aluminum foil.}

A positive electrode was obtained by punching so that the area where the positive electrode mixture layer was formed was 28 mm × 48 mm and the area where the positive electrode mixture layer was not formed was 10 mm × 13 mm.

<Preparation of non-aqueous electrolyte solution>
_{LiPF 6} was dissolved in a mixed solvent (mass ratio 1: 1: 1) of ethylene carbonate, dimethyl carbonate and methyl ethyl carbonate so as to have a mass ratio of 1.5 M to obtain a non-aqueous electrolyte solution.

<Manufacturing of non-aqueous power storage element (1)>
Three positive electrodes and four negative electrodes were alternately laminated via a film separator to obtain an electrode element. At this time, a nickel tab as a lead wire was welded together in the region where the negative electrode mixture layer and the mixed layer of the negative electrode were not formed. In addition, aluminum tabs, which serve as lead wires, were welded together in the regions where the positive electrode mixture layer of the positive electrode was not formed.

After injecting a non-aqueous electrolytic solution into the electrode element, it was sealed with an aluminum laminate film to obtain a non-aqueous power storage element.

<Output of non-aqueous power storage element>
Connect the lead wire of the non-aqueous power storage element to the charge / discharge test device (manufactured by Hokuto Denko Co., Ltd.), charge it at a maximum voltage of 4.2 V and a current rate of 0.2 C for 5 hours with a constant current and constant voltage, and then pause for 10 minutes. Then, a constant current discharge was performed at a current rate of 0.2 C for 2.5 hours, and the charge rate of the non-aqueous power storage element was set to 50%. Next, the electric power was discharged for 10 seconds with a pulse of a current rate of 1C to 10C, and the electric power up to the 2.5V cutoff voltage was calculated from the correlation straight line between the voltage and the current after the discharge, and the output was calculated.

The output of the non-aqueous power storage element is good if it is 10.5 W or more.

FIG. 7 shows the relationship between the charge rate and the output of the non-aqueous power storage element of Example 25 and Comparative Example 9.

From FIG. 7, it can be seen that the non-aqueous power storage element of Example 25 has the same output characteristics as the non-aqueous power storage element of Comparative Example 9 in which the mixed layer is not formed on the negative electrode mixture layer.

<Manufacturing of non-aqueous power storage element (Part 2)>
A non-aqueous power storage element was obtained in the same manner as described above, except that the positive electrodes and the negative electrodes alternately laminated via the film separator were 23 and 24, respectively.

<Safety of non-aqueous power storage elements>
After connecting the lead wire of the non-aqueous power storage element to the charge / discharge test device (manufactured by Hokuto Denko Co., Ltd.) and charging it at a maximum voltage of 4.2 V and a current rate of 0.2 C for a constant current and constant voltage in 5 hours, a constant temperature bath at 40 ° C. It was left to stand for 5 days. Next, the battery is charged at a maximum voltage of 4.2 V and a current rate of 0.2 C in a constant current and constant voltage for 5 hours to set the charge rate to 100%, and then has a diameter of 4.5 mm perpendicular to the direction in which the electrodes are laminated. The presence or absence of smoke and ignition was observed with the nail pierced and intentionally short-circuited.

The safety of the non-aqueous power storage element was judged as ◯ when it did not ignite and x when it ignited.

Table 10 shows the evaluation results of the peel strength of the mixed layer of the negative electrode, the output of the non-aqueous power storage element, and the safety.

表２から、実施例２５〜３０の負極は、非水系蓄電素子の出力と安全性を両立している（非水系蓄電素子の安全性を確保しながら出力特性が向上している）ことがわかる。

From Table 2, it can be seen that the negative electrodes of Examples 25 to 30 have both the output and safety of the non-aqueous power storage element (the output characteristics are improved while ensuring the safety of the non-aqueous power storage element). ..

On the other hand, in the negative electrode of Comparative Example 9, since the insulating inorganic particles do not exist on the negative electrode mixture layer, the safety of the non-aqueous power storage element is low. It is considered that this is because the insulation property is not guaranteed against the internal short circuit and Joule heat generation is generated.

Further, the negative electrode of Comparative Example 10 has a low output because insulating inorganic particles and a binder resin are present on the negative electrode mixture layer. It is considered that this is because the internal resistance of the non-aqueous power storage element has increased due to the lack of ionic conductivity of the binder resin.

Although the embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments, and various modifications and modifications can be made within the scope of the invention described in the claims. ..

1 Electrochemical element 10, 17 Negative electrode 11 Negative electrode base 12 Negative electrode mixture layer 13 Mixed layer 20, 27 Positive electrode 21 Positive electrode base 22 Positive electrode mixture layer 30 Separator 40 Electrode element 41, 42 Lead wire 51 Electrolyte layer 52 Exterior

Special Table 2015-518644

Claims (11)

Formed on the electrode substrate via the electrode mixture layer,
A mixed layer for electrodes containing an ionic conductive resin and insulating inorganic particles. The mixed layer for electrodes according to claim 1, wherein the ionic conductive resin contains a resin having an oxyethylene group. The mixed layer for electrodes according to claim 1 or 2, wherein the mass ratio of the ionic conductive resin to the insulating inorganic particles is 0.5% or more and 50% or less. The mixed layer for electrodes according to claim 3, wherein the mass ratio of the ionic conductive resin to the insulating inorganic particles is 0.5% or more and 20% or less. The mixed layer for electrodes according to any one of claims 1 to 4, further comprising a lithium salt. The mixed layer for electrodes according to any one of claims 1 to 5, wherein the ionic conductive resin contains a resin having a carboxyl group. The mixed layer for an electrode according to any one of claims 1 to 6, wherein the ionic conductive resin contains a resin having a sulfonic acid group and / or a resin having a phosphonic acid group. The mixed layer for electrodes according to any one of claims 1 to 7, wherein the insulating inorganic particles contain an aluminum compound. The mixed layer for electrodes according to claim 8, wherein the aluminum compound is α-alumina. An electrode mixture layer and a mixed layer are sequentially formed on the electrode substrate.
The electrode, wherein the mixed layer is the mixed layer for an electrode according to any one of claims 1 to 9. An electrochemical device having the electrode according to claim 10.

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