JP2021089887A - Liquid composition set and method for manufacturing electrochemical element - Google Patents

Abstract

To provide a liquid composition set that has a high degree of freedom in design and can be used for formation of a positive electrode mixed material layer or a negative electrode mixed material layer that constitutes an electrochemical element.SOLUTION: A liquid composition set is used for formation of a positive electrode mixed material layer or a negative electrode mixed material layer. The liquid composition set has a first liquid composition in which a first electrode material is dissolved or dispersed in a first liquid, and a second liquid composition in which a second electrode material different from the first electrode material is dissolved or dispersed in a second liquid different from the first liquid. The second electrode material is more easily dissolved or dispersed in the second liquid than in the first liquid.SELECTED DRAWING: None

Description

The present invention relates to a liquid composition set and a method for producing an electrochemical device.

Electrochemical elements such as lithium ion secondary batteries, electric double layer capacitors, lithium ion capacitors, and redox capacitors are installed in portable devices, hybrid vehicles, electric vehicles, and the like, and demand is expanding. In addition, the needs for thin batteries to be mounted on various wearable devices and medical patches are increasing, and the demands for electrochemical elements are diversifying.

Conventionally, as a method for manufacturing an electrode constituting an electrochemical element, an electrode material and a liquid composition for an electrode mixture layer containing a liquid are applied by using a die coater, a comma coater, a reverse roll coater, or the like. A method of forming an electrode mixture layer on an electrode substrate is known.

For example, the electrode mixture layer can be formed by screen-printing the liquid composition for the electrode mixture layer on the electrode substrate.

However, in order to screen-print in a shape that meets the needs, it is necessary to manufacture a screen for each need.

Therefore, a method of forming an electrode mixture layer by discharging a liquid composition for an electrode mixture layer onto an electrode substrate using a liquid discharge device has been studied (see, for example, Patent Documents 1 and 2). ).

For example, from the viewpoint of the drying efficiency of the liquid composition for the electrode mixture layer, it is conceivable to use a liquid having a low boiling point as the liquid contained in the liquid composition for the electrode mixture layer.

However, the solubility or dispersibility of an electrode material (for example, an active material, a conductive additive, a binder, an electrolyte, etc.) having good properties of an electrochemical element in a liquid having a low boiling point is not always good. ..

Further, from the viewpoint of the discharge characteristics of the liquid composition for the electrode mixture layer, it is conceivable to use a liquid having a high boiling point as the liquid contained in the liquid composition for the electrode mixture layer.

Therefore, when designing a liquid composition for an electrode mixture layer that has good electrochemical element characteristics and discharge characteristics, the electrochemical characteristics of the liquid and the electrochemical characteristics of the electrode material are taken into consideration, and at the same time, the electrode It is necessary to consider multiple conditions such as solubility and dispersibility of the material in the liquid. Therefore, it is desired to improve the degree of freedom in designing the liquid composition for the electrode mixture layer.

An object of the present invention is to provide a liquid composition set having a high degree of freedom in design and which can be used for forming a positive electrode mixture layer or a negative electrode mixture layer constituting an electrochemical element.

One aspect of the present invention is a liquid composition set used for forming a positive electrode mixture layer or a negative electrode mixture layer, wherein the first electrode material is dissolved or dispersed in the first liquid. The composition has a second liquid composition in which a second electrode material different from the first electrode material is dissolved or dispersed in a second liquid different from the first liquid. The electrode material of 2 is more easily dissolved or dispersed in the second liquid than the first liquid.

According to the present invention, it is possible to provide a liquid composition set that has a high degree of freedom in design and can be used for forming a positive electrode mixture layer or a negative electrode mixture layer constituting an electrochemical element.

It is sectional drawing which shows an example of the negative electrode of this embodiment. It is a schematic diagram which shows an example of the manufacturing method of the negative electrode of this embodiment. It is a schematic diagram which shows another example of the manufacturing method of the negative electrode of this embodiment. It is a figure which shows another example of the manufacturing method of the negative electrode of this embodiment. It is a figure which shows another example of the manufacturing method of the negative electrode of this embodiment. It is a schematic diagram which shows the modification of the liquid discharge device of FIGS. 2-5. It is sectional drawing which shows an example of the positive electrode of this embodiment. 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.

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.

[Liquid composition set]
The liquid composition set of the present embodiment is used for forming a positive electrode mixture layer or a negative electrode mixture layer.

The liquid composition set of the present embodiment includes a first liquid composition in which the first electrode material is dissolved or dispersed in the first liquid, and a second electrode material different from the first electrode material. It has a second liquid composition that is dissolved or dispersed in a second liquid that is different from the first liquid.

In the present specification and claims, the liquid means a liquid that functions as a medium for dissolving or dispersing the electrode material, and does not include a liquid (for example, a monomer) that functions as a precursor of the binder.

Here, the first electrode material can contain at least one of an active material, a conductive auxiliary agent, a binder, and an electrolyte, and preferably contains a conductive auxiliary agent. This improves the characteristics of the electrochemical device.

The second electrode material can also contain at least one of an active material, a conductive additive, a binder, and an electrolyte.

In the liquid composition set of the present embodiment, the second electrode material is more likely to dissolve or disperse in the second liquid than in the first liquid.

As a result, in the liquid composition set of the present embodiment, a liquid composition set having a high degree of freedom in design and excellent characteristics of the electrochemical element and discharge characteristics can be obtained.

The liquid composition set of the present embodiment may have at least one of the first liquid composition and the second liquid composition.

Here, at least one of the first liquid composition and the second liquid composition indicates only the first liquid composition, only the second liquid composition, or the first liquid composition. This is the case where both the product and the second liquid composition are shown.

In addition, having at least one of the first liquid composition and the second liquid composition means that the first liquid composition and the second liquid composition are each one of the first liquid compositions. When having two or more kinds of liquid compositions and having one kind of second liquid composition, when having one kind of first liquid composition and having two or more kinds of second liquid composition, or having one kind of first liquid The case where both the composition and the second liquid composition have two or more kinds is shown.

In general, the conditions under which any of the electrode active material, the conductive auxiliary agent, the binder, and the electrolyte constituting the electrode mixture layer are satisfactorily dissolved or dispersed in the liquid may differ depending on each. Further, even if any of the electrode active material, the conductive auxiliary agent, the binder, and the electrolyte constituting the electrode mixture layer is well dissolved or dispersed in the same liquid, when these are mixed, they are well dissolved or dispersed. It may disappear.

For multiple electrode materials of electrode active materials, conductive aids, binders, and electrolytes, which are expected to have good electrochemical element properties, these electrodes have different liquids that dissolve or disperse well. It can be difficult to eject a liquid composition that contains multiple electrode materials of the material.

Therefore, by having at least one of the first liquid composition and at least one of the second liquid compositions, the degree of freedom in designing the liquid composition is improved.

When at least one of the first electrode material and the second electrode material contains an active material, the content of the active material in the liquid composition is preferably 20% by mass or more, preferably 25% by mass or more. It is more preferable to have. When the content of the active material in the liquid composition is 20% by mass or more, the capacity of the electrochemical element is improved, and when it is 25% or more, the capacity of the electrochemical element is further improved.

The content of the active material in the liquid composition is preferably 60% by mass or less. When the content of the active material in the liquid composition is 60% by mass or less, the discharge property of the liquid composition is improved.

The first liquid composition and the second liquid composition preferably have a viscosity capable of being discharged from the liquid discharge head.

The viscosity of the liquid composition at 25 ° C. is preferably 200 mPa · s or less. When the viscosity of the liquid composition at 25 ° C. is 200 mPa · s or less, the discharge stability of the liquid composition is improved.

In the present specification and claims, the fact that the electrode material is dissolved in a liquid means that the viscosity of the liquid composition at 25 ° C. is 200 mPa · s or less.

Further, the second electrode material is more soluble in the second liquid than the first liquid when the second liquid is replaced with the first liquid in the second liquid composition. It means that the viscosity at 25 ° C. increases, or that the second electrode material becomes insoluble in the first liquid.

It is preferable that the maximum particle size of the first electrode material and the second electrode material is smaller than the nozzle diameter of the liquid discharge head.

Here, the maximum particle size indicates a particle size at which the volume-based particle size distribution is 100%. The maximum particle size can be measured by a particle size distribution meter using a laser diffraction method.

The mode diameter of the first electrode material and the second electrode material is preferably 20 μm or less, more preferably 10 μm or less, still more preferably 3 μm or less. When the mode diameter of the first electrode material and the second electrode material is 20 μm or less, the discharge stability and sedimentation resistance of the first liquid composition and the second liquid composition are improved, and the mode diameter is 10 μm or less. And, the discharge stability and sedimentation resistance of the first liquid composition and the second liquid composition are further improved, and when it is 3 μm or less, the discharge stability of the first liquid composition and the second liquid composition is improved. The property and sediment resistance are further improved.

Here, the mode diameter indicates the particle size that is the most frequent value of the particle size distribution. The mode diameter can be measured by a particle size distribution meter using a laser diffraction method.

In the present specification and claims, the fact that the electrode material is dispersed in the liquid means that the mode diameter of the liquid composition is 3 μm or less.

Further, the second electrode material is more easily dispersed in the second liquid than the first liquid when the second liquid is replaced with the first liquid in the second liquid composition. It means that the mode diameter increases or the second electrode material does not disperse in the first liquid.

The 10% diameter (d10) of the first electrode material and the second electrode material is preferably 0.10 μm or more, and more preferably 0.15 μm or more. When the median diameter (d10) of the first electrode material and the second electrode material is 0.10 μm or more, the storage stability of the liquid composition is improved, and when it is 0.15 μm or more, the liquid composition is stored. Stability is further improved.

The 10% diameter of the electrode material can be measured by a particle size distribution meter using a laser diffraction method.

<Active material>
As the active material, a positive electrode active material or a negative electrode active material can be used.

The positive electrode active material or the negative electrode active material may be used alone or in combination of two or more.

The positive electrode active material is not particularly limited as long as it can occlude or release alkali metal ions, but an alkali metal-containing transition metal compound can be used.

Here, occlusion means that alkali metal ions are inserted into the negative electrode active material. Further, the release means that the alkali metal ion is desorbed from the negative electrode active material.

Examples of the alkali metal-containing transition metal compound include lithium-containing transition metal compounds such as a composite oxide containing one or more elements selected from the group consisting of cobalt, manganese, nickel, chromium, iron and vanadium and lithium. Be done.

Examples of the lithium-containing transition metal compound include lithium cobalt oxide, lithium nickel oxide, lithium manganate and the like.

As the alkali metal-containing transition metal compound _{, a polyanion compound having an XO-4} tetrahedron (X is P, S, As, Mo, W, Si, etc.) in the crystal structure can also be used. Among these, lithium-containing transition metal phosphoric acid compounds such as lithium iron phosphate and lithium vanadium phosphate are preferable in terms of cycle characteristics, and lithium vanadium phosphate is particularly preferable in terms of lithium diffusion coefficient and output characteristics. In terms of electron conductivity, the polyanionic compound is preferably composited by coating its surface with a conductive auxiliary agent such as a carbon material.

The negative electrode active material is not particularly limited as long as it can occlude or release alkali metal ions, but a carbon material containing graphite having a graphite-type crystal structure can be used.

Examples of the carbon material include natural graphite, artificial graphite, non-graphitizable carbon (hard carbon), easily graphitizable carbon (soft carbon) and the like.

Examples of the negative electrode active material other than the carbon material include lithium titanate and titanium oxide.

Further, from the viewpoint of the energy density of the non-aqueous power storage element, it is preferable to use a high-capacity material such as silicon, tin, a silicon alloy, a tin alloy, silicon oxide, silicon nitride, or tin oxide as the negative electrode active material.

<Electrolyte>
As the electrolyte, a material for forming a solid electrolyte layer can be used. The material constituting the solid electrolyte layer is not particularly limited as long as it is a solid substance having electron insulating properties and ionic conductivity, but sulfide-based solid electrolytes and oxide-based solid electrolytes are high. It is preferable from the viewpoint of having ionic conductivity.

Examples of the sulfide-based solid electrolyte include Li ₁₀ GeP ₂ S _{12 or Li 6} PS ₅ X having an algyrodite type crystal structure (X is F, Cl, Br, or I).

Examples of the oxide-based solid electrolyte include LLZ (Li ₇ La ₃ Zr ₂ O _{12 ) having a garnet-type crystal structure or LATP (Li 1 + x} Al _x Ti20 _x (PO ₄ ) ₃ ) (0) having a NASICON-type crystal structure. .1 ≤ x ≤ 0.4), LLT with a perovskite crystal structure (Li _0.33 La _0.55 TiO ₃ ), amorphous LIPON (Li _2.9 PO _3.3 N _0.4 ), etc. Can be mentioned.

These solid electrolytes may be used alone or in combination of two or more.

Examples of the electrolyte material to be dissolved or dispersed in the liquid to form these solid electrolyte layers include Li ₂ S, P ₂ S _{5 , Li Cl, which are precursors of the solid electrolyte, and Li 2} which is a material of the solid electrolyte. _{Examples thereof include SP 2} S ₅ series glass, Li ₇ P ₃ S ₁₁ glass ceramics, and the like.

Further, a material for forming a gel electrolyte layer can also be used as the electrolyte.

The gel electrolyte is not particularly limited as long as it exhibits ionic conductivity. For example, the polymers constituting the network structure of the gel electrolyte include polyethylene oxide, polypropylene oxide, polyacrylonitrile, polymethylmethacrylate, and polyvinyl chloride. Examples thereof include a copolymer of vinylidene fluoride and propylene hexafluoride, polyethylene carbonate and the like.

Further, examples of the solvent molecule retained in the gel electrolyte include an ionic liquid. As ionic liquids, methyl-1-propylpyrrolidinium bis (fluorosulfonylimide), 1-butyl-1-methylpyrrolidinium bis (fluorosulfonylimide), 1-methyl-1-propylpiperidinium bis (fluorosulfonylimide) Imid), 1-ethyl-3-methylimidazolium bis (fluorosulfonylimide), 1-methyl-3-propyl imidazolium bis (fluorosulfonylimide), N, N-diethyl-N-methyl-N- (2-) There are methoxyethyl) ammonium bis (fluorosulfonyl) imides.

Further, a liquid such as tetraglime, propylene carbonate, fluoroethylene carbonate, ethylene carbonate or diethyl carbonate may be mixed with a lithium salt.

The lithium salt is not particularly limited and may be appropriately selected depending on the intended purpose. For example, lithium hexafluorophosphate (LiPF ₆ ), lithium borofluoride (LiBF ₄ ), lithium hexafluoride (LiAsF ₆ ) , Lithium trifluoromethsulfonate (LiCF ₃ SO ₃ ), Lithium bis (trifluoromethylsulfonyl) imide (LiN (CF ₃ SO ₂ ) ₂ ), Lithium bis (pentafluoroethylsulfonyl) imide (LiN (C ₂ F ₅₎ SO ₂ ) ₂ ) and the like can be mentioned.

The gel electrolyte may be used alone or in combination of two or more.

In order to form these gel electrolyte layers, as the electrolyte material to be dissolved or dispersed in the liquid, a solution in which the above polymer compound and an ionic liquid or a lithium salt are dissolved may be used. Further, as the electrolyte material to be dissolved or dispersed in the liquid, a material serving as a precursor of the gel electrolyte (for example, poethylene oxide or polypropylene oxide having acrylate groups at both ends and a solution in which an ionic liquid or a lithium salt is dissolved) is used. A combination) may be used.

<Liquid>
The liquid is not particularly limited as long as it can disperse the positive electrode material or the negative electrode material, but is limited to water, ethylene glycol, propylene glycol, trimethylene glycol, N-methyl-2-pyrrolidone, 2-pyrrolidone, and cyclohexanone. , Ethyl lactate, butyl acetate, mesityrene, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono Butyl ether, 2-n-butoxymethanol, 2-dimethylethanol, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, normal hexane, heptane, octane, nonane, decane, diethyl ether, dibutyl ether, di- Examples thereof include tart-butyl ether, toluene, xylene, anisole, and mesityrene.

The liquid may be used alone or in combination of two or more.

<Conductive aid>
As the conductive auxiliary agent, for example, carbon materials such as carbon nanofibers, carbon nanotubes, graphene, and graphite particles can be used in addition to conductive carbon black formed by a furnace method, an acetylene method, a gasification method, or the like.

As the conductive auxiliary agent other than the carbon material, for example, metal particles such as aluminum and metal fibers can be used.

<Binder>
The binder is not particularly limited as long as it can bind the negative electrode materials to each other, the positive electrode materials to each other, the negative electrode material to the negative electrode substrate, and the positive electrode material to the positive electrode substrate, but from the viewpoint of suppressing nozzle clogging of the liquid discharge head , It is preferable to use a material that does not increase the viscosity of the liquid composition.

As a material that does not increase the viscosity of the liquid composition, a polymer compound or the like that can be dissolved or dispersed in the liquid can be used.

When a polymer compound that can be dissolved in a liquid is used, the liquid composition in which the polymer compound is dissolved in the liquid may have a viscosity that can be discharged from the liquid discharge head.

Examples of the polymer compound include polyamide compounds, polyimide compounds, polyamide-imide, ethylene-propylene-butadiene rubber (EPBR), styrene-butadiene rubber (SBR), nitrile butadiene rubber (HNBR), isoprene rubber, polyisobutene, and polyethylene glycol (. PEO), polymethylmethacrylic acid (PMMA), polyethylene vinyl acetate (PEVA) and the like.

Polymer particles may be used as the polymer compound that can be dissolved in a liquid.

The maximum particle size of the polymer particles may be smaller than the nozzle diameter of the liquid discharge head.

The mode diameter of the polymer particles is preferably 0.01 to 1 μm.

Examples of the material constituting the polymer particles include polyvinylidene fluoride, acrylic resin, styrene-butadiene rubber, polyethylene, polypropylene, polyurethane, nylon, polytetrafluoroethylene, polyphenylene sulfide, polyethylene teflate, and polybutylene teflate. Thermoplastic resin can be mentioned.

In addition, the electrode material of the present embodiment may contain a binder precursor, a dispersant, and the like as electrode materials other than the above, as long as the effects of the present invention are not impaired.

<Binder precursor>
Examples of the binder precursor include polymerizable compounds such as monomers.

When a polymerizable compound is used, for example, it is polymerized by applying a liquid composition in which the polymerizable compound is dissolved in a liquid and then heating it or irradiating it with non-ionizing radiation, ionizing radiation, infrared rays, or the like. , Generated by the binder.

The polymerizable compound is not particularly limited as long as it has a polymerizable group, but a compound capable of polymerizing at 25 ° C. is preferable.

When a polymerizable compound is used, a plurality of pores can be formed inside the electrode mixture layer. At this time, it is preferable that the vacancies inside the electrode mixture layer are connected to other vacancies and expand three-dimensionally. By connecting the pores, the electrolyte sufficiently penetrates into the electrode mixture layer, and the ionic conductivity of the electrochemical device is improved.

The polymerizable compound may be monofunctional or polyfunctional.

The polyfunctional polymerizable compound means a compound having two or more polymerizable groups.

The polyfunctional polymerizable compound is not particularly limited as long as it can be polymerized by heating or irradiation with non-ionizing radiation, ionizing radiation, or infrared rays, and is, for example, an acrylate resin, a metal acrylate resin, or a urethane acrylate resin. , Vinyl ester resin, unsaturated polyester, epoxy resin, oxetane resin, vinyl ether, resin utilizing ene-thiol reaction and the like. Among these, acrylate resin, methacrylate resin, urethane acrylate resin, and vinyl ester resin are preferable from the viewpoint of productivity.

Since the polyfunctional acrylate resin can be used as a Michael acceptor, it can undergo a polyaddition reaction with a Michael donor.

Examples of the polyfunctional acrylate resin include low molecular weight compounds such as dipropylene glycol diacrylate and neopentyl glycol diacrylate, and bifunctional acrylates such as high molecular weight compounds such as polyethylene glycol diacrylate, urethane acrylate and epoxy acrylate; Trifunctional acrylates such as methylolpropan triacrylate and pentaerythritol triacrylate; tetrafunctional or higher functional acrylates such as pentaerythritol tetraacrylate and dipentaerythritol hexaacrylate can be mentioned.

Examples of the Michael donor include polyfunctional amines, polyfunctional thiols and the like.

Examples of the polyfunctional amine include ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,2-phenylenediamine, and 1,3-. Examples thereof include phenylenediamine and 1,4-phenylenediamine.

Examples of polyfunctional thiols include 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 2,3-butanedithiol, 1,5-pentanedithiol, and 1,6-hexanedithiol. , 1,2-benzenedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, 1,3,5-benzenetrithiol, 4,4-biphenyldithiol and the like.

As the catalyst for the polyaddition reaction, a catalyst usually used for the Michael addition reaction can be appropriately selected and used. For example, an amine catalyst such as diazabicycloundecene (DBU) or N-methyldicyclohexylamine, sodium, etc. can be used. Examples thereof include base catalysts such as methoxide, sodium ethoxide, potassium t-butoxide, sodium hydroxide and tetramethylammonium hydroxide, metallic sodium, butyl lithium and the like.

Examples of the polymerizable compound capable of addition polymerization (radical polymerization) include milsen, kalen, osimene, pinen, limonene, camphene, terpinolene, tricyclene, terpinen, fenchen, ferlandrene, silbestrene, sabinene, dipentene, and the like. Esters made by epoxidizing the double bond of a terpene having an unsaturated bond such as bornene, isopregol, or carboxylic and adding acrylic acid or methacrylic acid; , Mentor, terpeneol, twill alcohol, citronellal, yonon, iron, cinerol, citral, pinol, cyclocitral, carbomentone, ascaridol, safranal, piperitol, mentenmonool, dihydrocarboxylic, carbeol, scalaleol, manol, hinokiol, ferginol , Totalol, Sugiol, Farnesol, Patchouli Alcohol, Nerolidol, Carotole, Casinol, Lanceol, Eudesmol, Fitol and other terpene-derived alcohols and esters of acrylic acid or methacrylic acid; citronerolic acid, hinokiic acid, Santalic acid; , Ferrandral, Pimelitenone, Perylaldehyde, Tuyon, Karon, Dageton, Shono, Visabolen, Santalen, Genghive Ren, Cariophyllen, Kurkmen, Sedren, Kajinen, Longihoren, Sesquibenihen, Sedrol, Guayor, Kessoglycol, Ciperon, Elemophyllon, Zelmophyllon , Podocalprene, Millen, Phyllocladen, Totarene, Ketomanoyl oxide, Manoyl oxide, Avietinic acid, Pimalic acid, Neo-Abietinic acid, Levopimalic acid, Iso-d-Pimalic acid, Agatendicarboxylic acid, Rubenic acid, Carotinoid, Peralialdehyde Examples thereof include acrylates or methacrylates having a skeleton such as piperitone, ascaridol, pipen, fenken, sesquiterpenes, diterpenes and triterpenes in the side chain.

As the polymerization initiator, for example, a photopolymerization initiator and a thermal polymerization initiator can be used.

As the photopolymerization initiator, a photoradical generator can be used.

Examples of the photoradical generator include α-hydroxyacetophenone, α-aminoacetophenone, 4-aroyl-1,3-dioxolane, benzylketal, 2,2-diethoxyacetophenone, p-dimethylaminoacetophen, and p-dimethyl. Aminopropiophenone, benzophenone, 2-chlorobenzophenone, 4,4'-dichlorobenzophene, 4,4'-bis (diethylamino) benzophenone, Michler ketone, benzyl, benzoin, benzyldimethylketal, tetramethylthium monosulfide, thioxanthone, 2-Chlorothioxanthone, 2-methylthioxanthone, azobisisobutyronitrile, benzoimpaoxide, di-tert-butylperoxide, (1-hydroxycyclohexyl) phenylketone, 2-hydroxy-2-methyl-1-phenyl- 1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, methylbenzoylformate, benzoin isopropyl ether, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether, benzoin n- Benzoin alkyl ethers such as butyl ether and benzoin n-propyl ether, (1-hydroxycyclohexyl) phenylketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1, (1-hydroxycyclohexyl) phenyl ketone, 2,2-dimethoxy-1,2-bis (eta ^{5-2,4-cyclopentadiene-1-yl)} - bis [2,6-difluoro-3-(1H-pyrrol -1-Il) Phenyl] Titanium, Bis (2,4,6-trimethylbenzoyl) Phenylphosphenyl Oxide, 2-Methyl-1- [4- (Methylthio) Phenyl] -2-Molihorinopropan-1-one, 2-Hydroxy-2-methyl-1-phenylpropan-1-one (Darocure 1173), bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, 1- [4- (2- (2-) Hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one, monoacylphosphinoxide, diacylphosphinoxide, titanosen, fluorescein, anthraquinone, thioxanthone, xantone, loffindimer, trihalomethyl compound, diha Examples thereof include lomethyl compounds, active ester compounds, and organoboron compounds.

A photocrosslinked radical generator such as a bisazido compound such as 2,2'-azobis (2,4-dimethylvaleronitrile) may be used in combination with the photoradical generator.

Examples of the thermal polymerization initiator include azobisisobutyronitrile (AIBN) and the like.

A photoacid generator may be used as the polymerization initiator. In this case, when the applied liquid composition is irradiated with light, the photoacid generator generates an acid and the polymerizable compound is polymerized.

Examples of the polymerizable compound that polymerizes in the presence of an acid include a compound having a cyclic ether group such as an epoxy group, an oxetane group, and an oxolane group, an acrylic compound or a vinyl compound having the above-mentioned cyclic ether group in the side chain, and a carbonate-based compound. Cationic polymerization of compounds, low molecular weight melamine compounds, vinyl ethers, vinyl carbazoles, styrene derivatives, α-methylstyrene derivatives, vinyl alcohols and vinyl alcohol esters such as ester compounds of acrylic acid, methacrylic acid, etc. Examples thereof include a monomer having a vinyl group capable of.

Examples of the photoacid generator include onium salt, diazonium salt, quinonediazide, organic halide, aromatic sulfonate, disulfone compound, sulfonyl compound, sulfonate, sulfonium salt, sulfamide, iodonium salt, sulfonyldiazomethane compound and the like. Of these, onium salts are preferred.

Examples of the onium salt include fluoroborate ion, hexafluoroantimonate ion, hexafluoroarsenate ion, trifluoromethanesulfonate ion, diazonium salt having p-toluenesulfonate ion as a counterion, phosphonium salt, sulfonium salt and the like. ..

As a photoacid generator other than the above, triazine halide can be used.

The photoacid generator may be used alone or in combination of two or more. When a photoacid generator is used, a sensitizing dye may be used in combination.

Examples of the sensitizing dye include acridine, benzoflavin, perylene, anthracene, and laser dye.

<Dispersant>
The liquid composition may further contain a dispersant.

The dispersant is not particularly limited as long as it can improve the dispersibility of the electrode material in the liquid, and is not particularly limited. For example, a polycarboxylic acid type, a naphthalenesulfonic acid formarin condensation type, a polyethylene glycol, or a polycarboxylic acid moiety. High molecular weight dispersants such as alkyl esters, polyethers and polyalkylene polyamines, low molecular weight dispersants such as alkyl sulfonic acids, quaternary ammoniums, higher alcohol alkylene oxides, polyhydric alcohol esters and alkyl polyamines. , Inorganic dispersants such as polyphosphate-based dispersants and the like.

[Manufacturing method of electrochemical device]
The method for producing an electrochemical element of the present embodiment includes a step of applying the liquid composition set of the present embodiment on an electrode substrate to form an electrode mixture layer.

Here, as a method of applying the liquid composition set on the electrode substrate, a method of sequentially applying the liquid composition constituting the liquid composition set on the electrode substrate, a method of sequentially applying the liquid composition constituting the liquid composition set, and the liquid composition constituting the liquid composition set are used. , A method of applying the coating onto the electrode substrate substantially at the same time, and the like.

The method for applying the liquid composition is not particularly limited, and for example, a spin coating method, a casting method, a microgravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, a dip coating method, and a slit. Examples thereof include a coating method, a capillary coating method, a spray coating method, a nozzle coating method, a gravure printing method, a screen printing method, a flexographic printing method, an offset printing method, a reverse printing method, and a liquid ejection method. Among these, the liquid discharge method is particularly preferable from the viewpoint of electrode productivity.

When the liquid composition contains a polymerizable compound, the polymerizable compound is polymerized by applying the liquid composition on an electrode substrate and then heating it or irradiating it with non-ionizing radiation, ionizing radiation, infrared rays, or the like. , Generated by the binder.

The material constituting the electrode substrate (current collector) is not particularly limited as long as it has conductivity and is stable with respect to the applied potential.

<Negative electrode>
FIG. 1 shows an example of the negative electrode of the present embodiment.

In the negative electrode 10, a negative electrode mixture layer 12 is formed on one side of the negative electrode substrate 11.

The negative electrode mixture layer 12 may be formed on both sides of the negative electrode substrate 11.

The shape of the negative electrode 10 is not particularly limited, and examples thereof include a flat plate shape and the like.

Examples of the material constituting the negative electrode substrate 11 include stainless steel, nickel, aluminum, copper and the like.

<Manufacturing method of negative electrode>
FIG. 2 shows an example of the method for manufacturing the negative electrode of the present embodiment.

The method for manufacturing the negative electrode 10 includes a step of sequentially discharging the first liquid composition 12A and the second liquid composition 12B onto the negative electrode substrate 11 using the liquid discharge devices 300A and 300B.

Here, the liquid composition contains a negative electrode material, and the negative electrode material contains a negative electrode active material, a conductive auxiliary agent, a binder or a precursor of a binder.

The liquid composition 12A is stored in the tank 307A and is supplied from the tank 307A to the liquid discharge head 306A via the tube 308A. Similarly, the liquid composition 12B is stored in the tank 307B and is supplied from the tank 307B to the liquid discharge head 306B via the tube 308B.

The number of liquid discharge devices is not limited to two, and may be three or more.

Further, the liquid discharge device 300A (or 300B) is provided with a mechanism for capping the nozzle in order to prevent drying when the liquid composition 12A (or 12B) is not discharged from the liquid discharge head 306A (or 306B). You may be.

When manufacturing the negative electrode 10, after the negative electrode substrate 11 is placed on the stage 400 that can be heated, the liquid droplets of the first liquid composition 12A, the second droplets, are released from the liquid discharge heads 306A and 306B. The droplets of the liquid composition 12B are sequentially discharged onto the negative electrode substrate 11. At this time, the stage 400 may move, or the liquid discharge heads 306A and 306B may move.

Further, when the liquid composition 12A discharged to the negative electrode substrate 11 is heated, it may be heated by the stage 400 or by a heating mechanism other than the stage 400.

The heating mechanism is not particularly limited as long as it does not come into direct contact with the first liquid composition 12A and the second liquid composition 12B, and examples thereof include a resistance heating heater, an infrared heater, and a fan heater.

A plurality of heating mechanisms may be installed.

Further, a curing device using ultraviolet rays for polymerizing the polymerizable compound may be installed.

The heating temperature is not particularly limited as long as it is the temperature at which the polymerizable compound is polymerized, and is preferably in the range of 70 to 150 ° C. from the viewpoint of energy consumption.

Further, when heating the liquid composition 12A discharged to the negative electrode substrate 11, ultraviolet light may be irradiated.

In the method for manufacturing a negative electrode according to the present embodiment, the negative electrode mixture layer 12 is formed on the negative electrode substrate 11, and the negative electrode 10 is obtained.

FIG. 3 shows another example of the method for manufacturing the negative electrode of the present embodiment.

The method for manufacturing the negative electrode 10 includes a step of sequentially discharging the first liquid composition 12A and the second liquid composition 12B onto the negative electrode substrate 11 using the liquid discharge device 300C.

The liquid composition 12A is stored in the tank 307A and is supplied from the tank 307A to the liquid discharge head 306C via the tube 308A. Similarly, the liquid composition 12B is stored in the tank 307B and is supplied from the tank 307B to the liquid discharge head 306C via the tube 308B.

When manufacturing the negative electrode 10, after the negative electrode substrate 11 is placed on the stage 400 that can be heated, a droplet of the first liquid composition 12A and a second liquid composition are discharged from the liquid discharge head 306C. The droplets of the object 12B are sequentially discharged to the negative electrode substrate 11.

FIG. 4 shows another example of the method for manufacturing the negative electrode of the present embodiment.

The method for manufacturing the negative electrode 10 includes a step of sequentially discharging the first liquid composition 12A and the second liquid composition 12B onto the negative electrode substrate 11 using the liquid discharge devices 300A and 300B.

First, an elongated negative electrode substrate 11 is prepared. Then, the negative electrode substrate 11 is wound around the tubular core, and the negative electrode base 11 is set on the feeding roller 304 and the winding roller 305 so that the side forming the negative electrode mixture layer 12 is on the upper side in the drawing. Here, the feeding roller 304 and the winding roller 305 rotate counterclockwise, and the negative electrode substrate 11 is conveyed from right to left in the drawing. Then, from the liquid discharge heads 306A and 306B installed above the negative electrode substrate 11 between the delivery roller 304 and the take-up roller 305, the droplets of the first liquid composition 12A, the first, in the same manner as in FIG. The droplets of the liquid composition 12B of 2 are discharged onto the negative electrode substrate 11 which is sequentially conveyed. The droplets of the first liquid composition 12A and the droplets of the second liquid composition 12B are ejected so as to cover at least a part of the negative electrode substrate 11.

A plurality of liquid discharge heads 306A and 306B may be installed in a direction substantially parallel to or substantially perpendicular to the transport direction of the negative electrode substrate 11.

Further, in the same manner as in FIG. 3, a liquid discharge device 300C may be installed instead of the liquid discharge devices 300A and 300B (see FIG. 5).

Next, the negative electrode substrate 11 on which the droplets of the first liquid composition 12A and the droplets of the second liquid composition 12B are discharged is conveyed to the heating mechanism 309 by the delivery roller 304 and the take-up roller 305. .. As a result, the first liquid composition 12A and the second liquid composition 12B on the negative electrode substrate 11 are dried to form the negative electrode mixture layer 12, and the negative electrode 10 is obtained. After that, the negative electrode 10 is cut to a desired size by punching or the like.

The heating mechanism 309 is not particularly limited as long as it does not come into direct contact with the first liquid composition 12A and the second liquid composition 12B, and examples thereof include a resistance heating heater, an infrared heater, and a fan heater.

The heating mechanism 309 may be installed on either the upper or lower side of the negative electrode substrate 11, or a plurality of heating mechanisms 309 may be installed.

The heating temperature is not particularly limited as long as it is the temperature at which the polymerizable compound is polymerized, and is preferably in the range of 70 to 150 ° C. from the viewpoint of energy consumption.

Further, when heating the liquid composition 12A discharged to the negative electrode substrate 11, ultraviolet light may be irradiated.

FIG. 6 shows a modified example of the liquid discharge devices 300A and 300B.

By controlling the pump 310A and the valves 311A and 312A in the liquid discharge device 300A', the first liquid composition 12A can circulate the liquid discharge head 306A, the tank 307A, and the tube 308A. Similarly, in the liquid discharge device 300B', by controlling the pump 310B and the valves 311B and 312B, the second liquid composition 12B can circulate the liquid discharge head 306B, the tank 307B, and the tube 308B. ..

Further, the liquid discharge device 300A'is provided with an external tank 313A, and controls the pump 310A and the valves 311A, 312A and 314A when the first liquid composition 12A in the tank 307A decreases. It is also possible to supply the first liquid composition 12A from the external tank 313A to the tank 307A. Similarly, the liquid discharge device 300B'is provided with an external tank 313B and controls the pump 310B and the valves 311B, 312B and 314B when the second liquid composition 12B in the tank 307B decreases. Therefore, it is also possible to supply the second liquid composition 12B from the external tank 313B to the tank 307B.

When the liquid discharge device is used, the first liquid composition 12A and the second liquid composition 12B are discharged to the target portion of the negative electrode base 11 (the region of the negative electrode base 11 on which the negative electrode mixture layer 12 is to be formed). Can be done. Further, when the liquid discharge device is used, the surfaces of the negative electrode base 11 and the negative electrode mixture layer 12 that are in contact with each other can be bonded to each other. Further, by using the liquid discharge device, the thickness of the negative electrode mixture layer 12 can be made uniform.

<Positive electrode>
FIG. 7 shows an example of the positive electrode of the present embodiment.

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

The positive electrode mixture layer 22 may be formed on both sides of the positive electrode substrate 21.

The shape of the positive electrode 20 is not particularly limited, and examples thereof include a flat plate shape.

Examples of the material constituting the positive electrode substrate 21 include stainless steel, aluminum, titanium, tantalum and the like.

<Manufacturing method of positive electrode>
The method for manufacturing the positive electrode 20 is the same as the method for manufacturing the negative electrode 10 except that the positive electrode 20 is formed on the positive electrode mixture layer 22 on the positive electrode substrate 21.

Here, the liquid composition contains a positive electrode material, and the positive electrode material contains a positive electrode active material, a conductive auxiliary agent, a binder or a precursor of a binder.

<Electrode element>
FIG. 8 shows an example of an electrode element used in the electrochemical element of the present embodiment.

In the electrode element 40, a negative electrode 15 and a positive electrode 25 are laminated via a separator 30. Here, the positive electrode 25 is laminated on both sides of the negative electrode 15. 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 15 is the same as the negative electrode 10 except that the negative electrode mixture layers 12 are formed on both sides of the negative electrode substrate 11.

The positive electrode 25 is the same as the positive electrode 20 except that the positive electrode mixture layers 22 are formed on both surfaces of the positive electrode substrate 21.

The number of layers of the negative electrode 15 and the positive electrode 25 of the electrode element 40 is not particularly limited.

Further, the number of negative electrodes 15 and the number of positive electrodes 25 of the electrode element 40 may be the same or different.

<Separator>
The separator 30 is provided between the negative electrode 15 and the positive electrode 25, if necessary, in order to prevent a short circuit between the negative electrode 15 and the positive electrode 25.

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 blown non-woven fabric, polyamide non-woven fabric, glass fiber non-woven fabric, and micropore film. ..

The size of the separator 30 is not particularly limited as long as it can be used for an electrochemical element.

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

When a solid electrolyte is used, the separator 30 can be omitted.

<Electrochemical element>
FIG. 9 shows an example of the electrochemical device of the present embodiment.

In the electrochemical element 1, an electrolyte layer 51 is formed by injecting an aqueous electrolyte solution or a non-aqueous electrolyte into the electrode element 40 shown in FIG. 8, and the electrochemical element 1 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 examples thereof include an aqueous power storage element and a non-aqueous power storage element.

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.

<Electrolyte aqueous solution>
Examples of the electrolyte salt constituting the aqueous electrolyte 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. Among these, chain carbonate is preferable because of its high dissolving power of the electrolyte salt.

Further, the aprotic organic solvent preferably has a low viscosity.

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

The content of the chain carbonate in the non-aqueous solvent is preferably 50% by mass or more. When the content of the chain carbonate in the non-aqueous solvent is 50% by mass or more, even if the non-aqueous solvent other than the chain carbonate is a cyclic substance having a high dielectric constant (for example, cyclic carbonate, cyclic ester), it is cyclic. The content of the substance is reduced. Therefore, even if a non-aqueous electrolytic solution having a high concentration of 2 M or more is produced, the viscosity of the non-aqueous electrolytic solution is low, and the non-aqueous electrolytic solution permeates into the electrode and ion diffusion is good.

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, alkoxy tetrahydrofuran, 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>
The electrolyte salt is not particularly limited as long as it has high ionic conductivity and can be dissolved in a non-aqueous solvent.

The electrolyte salt preferably contains a halogen atom.

Examples of the cation constituting the electrolyte salt include lithium ion and the like.

Examples of the anion constituting the electrolyte salt, for _{^{example, BF 4 -, PF 6 -}} , AsF 6 -, CF 3 SO 3 -, (CF 3 SO 2) 2 N -, (C 2 F 5 SO 2) 2 N - And so on.

The lithium salt is not particularly limited and may be appropriately selected depending on the intended purpose. For example, lithium hexafluorophosphate (LiPF ₆ ), lithium borofluoride (LiBF ₄ ), lithium hexafluoride (LiAsF ₆₎ ), Lithium trifluoromethsulfonate (LiCF ₃ SO ₃ ), Lithium bis (trifluoromethylsulfonyl) imide (LiN (CF ₃ SO ₂ ) ₂ ), Lithium bis (pentafluoroethylsulfonyl) imide (LiN (C ₂ F) ₅ SO ₂ ) ₂ ) and the like can be mentioned. _{Among these, LiPF 6} is preferable from the viewpoint of ionic conductivity _{, and LiBF 4} is preferable from the viewpoint of stability.

The electrolyte salt may be used alone or in combination of two or more.

The concentration of the electrolyte salt in the non-aqueous electrolyte solution can be appropriately selected depending on the intended purpose, but when the non-aqueous storage element is a swing type, it is preferably 1 mol / L to 2 mol / L, and is non-aqueous. When the power storage element is a reserve type, it is preferably 2 mol / L to 4 mol / L.

<Use of electrochemical elements>
The use of the electrochemical element is not particularly limited, and for example, a laptop computer, a pen input computer, a mobile 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, minidiscs, 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. In the examples of the present invention, the application when the electrode material is a positive electrode active material and a negative electrode active material will be described, but the application when the electrode material is an electrode material other than the positive electrode active material and the negative electrode active material is also applied. The same is true.

[Particle size distribution of liquid composition]
The liquid composition was dispersed in water or an organic solvent using a laser diffraction type particle size distribution measuring device Mastersizer 3000 (manufactured by Malvern), and then the particle size distribution of the liquid composition was measured at 25 ° C.

[Viscosity of liquid composition]
No. B type viscometer (cone plate type viscometer). A CPA-40Z rotor was attached and the viscosity of the liquid composition at 100 rpm was measured at 25 ° C.

[Peeling strength of electrode mixture layer]
The peel strength of the electrode mixture layer was measured using an adhesive / film peeling analyzer VPA-3 (manufactured by Kyowa Interface Science Co., Ltd.) (peel strength test method). Specifically, after attaching cellophane tape to the surface of the test piece cut into a width of 1.8 cm and a length of 10 cm on the side of the electrode mixture layer, the peeling speed is 30 mm / min and the peeling angle is 90 °. Under the conditions, the cellophane tape was peeled off by 100 mm from one end of the test piece, and the stress at that time was measured. Such stress measurements were carried out 10 times to obtain a weighted average of the stresses, which was used as the peel strength of the electrode mixture layer.

[Capacity of positive electrodes A to F, A']
After punching the positive electrode into a round shape with a diameter of 16 mm, a positive electrode, a glass separator with a thickness of 100 μm (manufactured by ADVANTEC), a non-aqueous electrolyte solution 1, and lithium with a thickness of 200 μm as a counter electrode (Honjo Metal) are placed in a coin can. A non-aqueous power storage element was obtained.

The non-aqueous power storage element is charged at room temperature (25 ° C.) ^{at a constant current of 0.1 mA / cm 2} to a final charge voltage of 4.2 V, and then discharged to a constant current of 2.5 V at ^{0.1 mA / cm 2 for the initial stage.} Charging and discharging were carried out. Next, the non-aqueous power storage element was ^{charged with a constant current of 0.1 mA / cm 2} to 4.2 V, and then charged and discharged twice with a constant current discharge of ^{0.1 mA / cm 2 to 3.0 V.} The capacity per unit area of the positive electrode was measured.

The capacitance per unit area of the electrode was measured using a charge / discharge measuring device TOSCAT3001 (manufactured by Toyo System Co., Ltd.).

[Capacity of negative electrode A]
After punching the negative electrode into a round shape with a diameter of 16 mm, a negative electrode, a glass separator with a thickness of 100 μm (manufactured by ADVANTEC), a non-aqueous electrolyte solution 1, and lithium with a thickness of 200 μm as a counter electrode (Honjo Metal) are placed in a coin can. A non-aqueous power storage element was manufactured.

A non-aqueous power storage element is charged at room temperature (25 ° C.) ^{at a constant current of 0.1 mA / cm 2} to a final charging voltage of 1.0 V, and then discharged at a constant current of ^{0.1 mA / cm 2 to 2.0 V for initial charging.} Charging and discharging were carried out. Next, the non-aqueous power storage element was charged with a constant current of ^{0.1 mA / cm 2 to 1.0 V, and then a constant current discharge cycle of 0.1 mA / cm 2} with a constant current of 2.0 V was performed twice. , The capacity per unit area of the negative electrode was measured.

[Capacity of negative electrode B]
After punching the negative electrode into a round shape with a diameter of 16 mm, a negative electrode, a glass separator with a thickness of 100 μm (manufactured by ADVANTEC), a non-aqueous electrolyte solution 1, and lithium with a thickness of 200 μm as a counter electrode (Honjo Metal) are placed in a coin can. A non-aqueous power storage element was manufactured.

The non-aqueous power storage element is charged at room temperature (25 ° C.) ^{at a constant current of 0.4 mA / cm 2} to a final charging voltage of 0.2 V, and then discharged at a constant current of ^{0.4 mA / cm 2 to 2.0 V at the initial stage.} Charging and discharging were carried out. Next, the non-aqueous power storage element was charged with a constant current of ^{0.1 mA / cm 2 to 0.2 V, and then a constant current discharge cycle of 0.4 mA / cm 2} with a constant current discharge of 2.0 V was performed twice. , The capacity per unit area of the negative electrode was measured.

[Positive electrode active material 1]
Vanadium pentoxide, lithium hydroxide, phosphoric acid, sucrose, and water were mixed to form a precipitate, which was then pulverized to obtain a precursor of vanadium phosphate particles. Next, the precursor of vanadium phosphate was calcined at 900 ° C. under a nitrogen atmosphere to obtain lithium vanadium phosphate (LVP) having a carbon content of 3% by mass. The LVP had a mode diameter of 10 μm. Further, the LVP was crushed using a jet mill to obtain the positive electrode active material 1. The positive electrode active material 1 had a mode diameter of 0.7 μm and a capacity per unit area of 0.26 mAh / cm ² .

[Positive electrode active material 2]
A nickel-based positive electrode active material (NCA) (manufactured by JFE Mineral Co., Ltd.) was crushed using a jet mill to obtain a positive electrode active material 2. The positive electrode active material 2 had a mode diameter of 1.5 μm and a capacity per unit area of 0.35 mAh / cm ² .

[Positive electrode active material 3]
Lithium cobalt oxide (LCO) (manufactured by Toyoshima Seisakusho Co., Ltd.) was crushed using a bead mill to obtain a positive electrode active material 3. The positive electrode active material 3 had a mode diameter of 1.3 μm and a capacity of 0.23 mAh / cm ² per unit area.

[Positive electrode active material 4]
Lithium manganate (LMO) (manufactured by Toyoshima Seisakusho Co., Ltd.) was crushed using a bead mill to obtain a positive electrode active material 4. The positive electrode active material 4 had a mode diameter of 1.3 μm and a capacity per unit area of 0.31 mAh / cm ² .

[Positive electrode active material 5]
Lithium iron phosphate (LFP) (manufactured by TATUNG FINE CHEMICALS) was crushed using a bead mill to obtain a positive electrode active material 5. The positive electrode active material 5 had a mode diameter of 1.0 μm and a capacity per unit area of 0.33 mAh / cm ² .

[Positive electrode active material 6]
A nickel-based positive electrode active material (NCA) (manufactured by JFE Mineral Co., Ltd.) was crushed using a bead mill to obtain a positive electrode active material 6. The positive electrode active material 6 had a mode diameter of 9.6 μm and a capacity of 0.35 mAh / cm ² per unit area.

[Negative electrode active material 1]
Lithium titanate (LTO) (manufactured by Ishihara Sangyo Co., Ltd.) was crushed using a bead mill to obtain a negative electrode active material 1. The negative electrode active material 1 had a mode diameter of 2.0 μm and a capacity of 0.31 mAh / cm ² per unit area.

[Negative electrode active material 2]
Silicon monoxide (SiO) (manufactured by Osaka Titanium Technologies Co., Ltd.) was crushed using a bead mill to obtain a negative electrode active material 2. The negative electrode active material 2 had a mode diameter of 1.0 μm and a capacity of 2.0 mAh / cm ² per unit area.

Table 1 shows the evaluation results of the mode diameter (μm) of the active material and the capacity per unit area.

[Non-aqueous electrolyte solution 1]
_{LiPF 6} is dissolved in a mixed solvent of propylene tylene carbonate (PC) / diethyl carbonate (DEC) / ethyl methyl carbonate (EMC) in a mass ratio of 1: 1: 1 so as to be 1.0 mol / L, and is non-aqueous. Electrolyte 1 (20 mL) was prepared.

(Example 1)
Positive electrode active material 1 (30% by mass) as a positive electrode active material, carbon black (3% by mass) as a conductive auxiliary agent, and ethyl lactate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (67% by mass) are mixed and first. Liquid composition A was prepared as the liquid composition of. The liquid composition A had a viscosity of 10.3 mPa · s and a mode diameter of 1.58 μm.

Polyamideimide (3% by mass) as a binder and N-methylpyrrolidone (NMP) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (97% by mass) were mixed to obtain liquid composition B as a second liquid composition. Made. In the liquid composition B, polyamide-imide was dissolved in N-methylpyrrolidone (NMP), and the viscosity was 9.6 mPa · s.

When a liquid composition was prepared by mixing polyamide-imide (3% by mass) and ethyl lactate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (97%), the liquid composition became cloudy and precipitated. That is, polyamide-imide, which is a second electrode material, is more easily dissolved in N-methylpyrrolidone, which is a second liquid, than ethyl lactate, which is a first liquid.

Using the liquid discharge device EV2500, the liquid compositions A and B were discharged onto an aluminum foil as shown in FIG. 2 to obtain a positive electrode A. At this time, the aluminum foil was fixed on the hot plate and heated to 130 ° C. The liquid compositions A and B had good discharge stability, and no discharge failure occurred. As a result, a positive electrode mixture layer having an active material amount of 2.0 mg / cm ² per unit area could be formed, and the liquid compositions A and B had good discharge efficiency.

In the positive electrode A, the peel strength of the positive electrode mixture was 1.05 N, and the capacity per unit area was 0.26 mAh / cm ² .

(Example 2)
A positive electrode A was obtained in the same manner as in Example 1 except that the liquid compositions A and B were discharged onto an aluminum foil as shown in FIG. 3 using the liquid discharge device EV2500. The liquid compositions A and B had good discharge stability, and no discharge failure occurred. As a result, it was possible to form a positive electrode mixture layer having an active material amount of 1.9 mg / cm ² per unit area, and the liquid compositions A and B had good discharge efficiency.

In the positive electrode A, the peel strength of the positive electrode mixture was 1.09 N, and the capacity per unit area was 0.25 mAh / cm ² .

(Example 3)
A positive electrode A was obtained in the same manner as in Example 1 except that the liquid compositions A and B were discharged onto an aluminum foil as shown in FIG. 4 using the liquid discharge device EV2500. The liquid compositions A and B had good discharge stability, and no discharge failure occurred. As a result, it was possible to form a positive electrode mixture layer having an active material amount of 1.9 mg / cm ² per unit area, and the liquid compositions A and B had good discharge efficiency.

In the positive electrode A, the peel strength of the positive electrode mixture was 1.11 N, and the capacity per unit area was 0.25 mAh / cm ² .

(Example 4)
A positive electrode A was obtained in the same manner as in Example 1 except that the liquid compositions A and B were discharged onto an aluminum foil as shown in FIG. 5 using the liquid discharge device EV2500. The liquid compositions A and B had good discharge stability, and no discharge failure occurred. As a result, a positive electrode mixture layer having an active material amount of 2.1 mg / cm ² per unit area could be formed, and the liquid compositions A and B had good discharge efficiency.

In the positive electrode A, the peel strength of the positive electrode mixture was 1.08 N, and the capacity per unit area was 0.27 mAh / cm ² .

(Example 5)
Positive electrode active material 2 (30% by mass), carbon black (3% by mass), ethyl lactate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (67% by mass) are mixed to prepare a liquid composition as a first liquid composition. C was prepared. The liquid composition C had a viscosity of 10.3 mPa · s and a mode diameter of 2.52 μm.

Polyamideimide (3% by mass) and N, N-dimethylacetamide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (97% by mass) were mixed to prepare a liquid composition D as a second liquid composition. In the liquid composition D, polyamide-imide was dissolved in N, N-dimethylacetamide, and the viscosity was 9.6 mPa · s.

When a liquid composition was prepared by mixing polyamide-imide (3% by mass) and ethyl lactate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (97%), the liquid composition became cloudy and precipitated. That is, polyamide-imide, which is a second electrode material, is more easily dissolved in N, N-dimethylacetamide, which is a second liquid, than ethyl lactate, which is a first liquid.

Using the liquid discharge device EV2500, the liquid compositions C and D were discharged onto an aluminum foil as shown in FIG. 2 to obtain a positive electrode B. At this time, the aluminum foil was fixed on the hot plate and heated to 120 ° C. The liquid compositions C and D had good discharge stability, and no discharge failure occurred. As a result, a positive electrode mixture layer having an active material amount of 2.2 mg / cm ² per unit area could be formed, and the liquid compositions C and D had good discharge efficiency.

In the positive electrode B, the peel strength of the positive electrode mixture was 1.14 N, and the capacity per unit area was 0.36 mAh / cm ² .

(Example 6)
Positive electrode active material 3 (30% by mass), carbon black (3% by mass), ethyl lactate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (67% by mass) are mixed to prepare a liquid composition as a first liquid composition. E was prepared. The liquid composition E had a viscosity of 10.7 mPa · s and a mode diameter of 1.22 μm.

Using the liquid discharge device EV2500, the liquid compositions E and D were discharged onto an aluminum foil as shown in FIG. 2 to obtain a positive electrode C. At this time, the aluminum foil was fixed on the hot plate and heated to 120 ° C. The liquid compositions E and D had good discharge stability, and no discharge failure occurred. As a result, a positive electrode mixture layer having an active material amount of 2.0 mg / cm ² per unit area could be formed, and the liquid compositions E and D had good discharge efficiency.

In the positive electrode C, the peel strength of the positive electrode mixture was 1.05 N, and the capacity per unit area was 0.23 mAh / cm ² .

(Example 7)
Positive electrode active material 4 (30% by mass), carbon black (3% by mass), ethyl lactate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (67% by mass) are mixed to prepare a liquid composition as a first liquid composition. F was prepared. The liquid composition F had a viscosity of 11.1 mPa · s and a mode diameter of 1.48 μm.

Using the liquid discharge device EV2500, the liquid compositions F and D were discharged onto an aluminum foil as shown in FIG. 2 to obtain a positive electrode D. At this time, the aluminum foil was fixed on the hot plate and heated to 120 ° C. The liquid compositions F and D had good discharge stability, and no discharge failure occurred. As a result, a positive electrode mixture layer having an active material amount of 2.0 mg / cm ² per unit area could be formed, and the liquid compositions F and D had good discharge efficiency.

The positive electrode D had a peeling strength of the positive electrode mixture of 1.08 N and a capacity per unit area of 0.25 mAh / cm ² .

(Example 8)
A liquid composition obtained by mixing positive electrode active material 5 (30% by mass), carbon black (3% by mass), and ethyl lactate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (67% by mass) as the first liquid composition. G was prepared. The liquid composition G had a viscosity of 10.9 mPa · s and a mode diameter of 2.11 μm.

Using the liquid discharge device EV2500, the liquid compositions G and D were discharged onto an aluminum foil as shown in FIG. 2 to obtain a positive electrode E. At this time, the aluminum foil was fixed on the hot plate and heated to 120 ° C. The liquid compositions G and D had good discharge stability, and no discharge failure occurred. As a result, a positive electrode mixture layer having an active material amount of 2.1 mg / cm ² per unit area could be formed, and the liquid compositions G and D had good discharge efficiency.

In the positive electrode E, the peel strength of the positive electrode mixture was 1.09 N, and the capacity per unit area was 0.30 mAh / cm ² .

(Example 9)
Negative electrode active material 1 (30% by mass), carbon black (1% by mass), ethyl lactate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (69% by mass) are mixed to prepare a liquid composition as a first liquid composition. H was prepared. The liquid composition H had a viscosity of 10.1 mPa · s and a mode diameter of 1.05 μm.

Using the liquid discharge device EV2500, the liquid compositions H and B were discharged onto an aluminum foil as shown in FIG. 2 to obtain a negative electrode A. At this time, the aluminum foil was fixed on the hot plate and heated to 120 ° C. The liquid compositions H and B had good discharge stability, and no discharge failure occurred. As a result, a negative electrode mixture layer having an active material amount of 2.1 mg / cm ² per unit area could be formed, and the liquid compositions H and B had good discharge efficiency.

In the negative electrode A, the peel strength of the negative electrode mixture was 1.05 N, and the capacity per unit area was 0.32 mAh / cm ² .

(Example 10)
Negative electrode active material 2 (30% by mass), carbon black (1% by mass), ethyl lactate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (69% by mass) are mixed to prepare a liquid composition as a first liquid composition. I was made. The liquid composition I had a viscosity of 13.1 mPa · s and a mode diameter of 2.15 μm.

Using the liquid discharge device EV2500, the liquid compositions I and B were discharged onto a copper foil as shown in FIG. 2 to obtain a negative electrode B. At this time, the copper foil was fixed on the hot plate and heated to 120 ° C. The liquid compositions I and B had good discharge stability, and no discharge failure occurred. As a result, it was possible to form a negative electrode mixture layer having an active material amount of 1.9 mg / cm ² per unit area, and the liquid compositions I and B had good discharge efficiency.

In the negative electrode B, the peel strength of the negative electrode mixture was 1.08 N, and the capacity per unit area was 2.0 mAh / cm ² .

(Example 11)
Polyamideimide (6% by mass) and N-methylpyrrolidone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (94% by mass) were mixed to prepare a liquid composition B'as a second liquid composition. In the liquid composition B', polyamide-imide was dissolved in N-methylpyrrolidone, and the viscosity was 9.6 mPa · s.

When a liquid composition was prepared by mixing polyamide-imide (6% by mass) and ethyl lactate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (94%), the liquid composition became cloudy and precipitated. That is, polyamide-imide, which is a second electrode material, is more easily dissolved in N-methylpyrrolidone, which is a second liquid, than ethyl lactate, which is a first liquid.

Using the liquid discharge device EV2500, the liquid compositions A and B'are discharged onto an aluminum foil as shown in FIG. 2 to obtain a positive electrode A. At this time, the aluminum foil was fixed on the hot plate and heated to 130 ° C. The liquid compositions A and B'have good discharge stability and no discharge failure occurred. As a result, it was possible to form a positive electrode mixture layer having an active material amount of 2.2 mg / cm ² per unit area, and the liquid compositions A and B'have good discharge efficiency.

In the positive electrode A, the peel strength of the positive electrode mixture was 2.17 N, and the capacity per unit area was 0.26 mAh / cm ² .

(Example 12)
Positive electrode active material 6 (40% by mass), carbon black (3% by mass), ethyl lactate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (57% by mass) are mixed to prepare a liquid composition J as a first liquid composition. Was produced. The liquid composition J had a viscosity of 11.9 mPa · s and a mode diameter of 9.11 μm.

Using the liquid discharge device EV2500, the liquid compositions J and B were discharged onto an aluminum foil as shown in FIG. 2 to obtain a positive electrode F. At this time, the aluminum foil was fixed on the hot plate and heated to 120 ° C. The liquid compositions J and B had good discharge stability, and no discharge failure occurred. As a result, a positive electrode mixture layer having an active material amount per unit area of 2.1 mg / cm2 could be formed, and the liquid compositions J and B had good discharge efficiency.

In the positive electrode F, the peel strength of the positive electrode mixture was 1.13 N, and the capacity per unit area was 0.34 mAh / cm2.

(Example 13)
Liquid composition K as a first liquid composition by mixing positive electrode active material 6 (50% by mass), carbon black (3% by mass), and ethyl lactate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (47% by mass). Was produced. The liquid composition K had a viscosity of 13.9 mPa · s and a mode diameter of 9.41 μm.

Using the liquid discharge device EV2500, the liquid compositions K and B were discharged onto an aluminum foil as shown in FIG. 2 to obtain a positive electrode F. At this time, the aluminum foil was fixed on the hot plate and heated to 120 ° C. The liquid compositions K and B had good discharge stability, and no discharge failure occurred. As a result, it was possible to form a positive electrode mixture layer having an active material amount of 2.2 mg / cm2 per unit area, and the liquid compositions K and B had good discharge efficiency.

The positive electrode F has a peeling strength of the positive electrode mixture of 1.09 N and a capacity of 0.36 per unit area.
It was mAh / cm2.

(Comparative Example 1)
Positive electrode active material 1 (30% by mass), carbon black (3% by mass), polyamide-imide (3% by mass), ethyl lactate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (64% by mass) are mixed, and the liquid composition L However, because the liquid composition L was gelled, it could not be discharged.

(Comparative Example 2)
Negative electrode active material 2 (30% by mass), carbon black (10% by mass), polyamide-imide (3% by mass), N-methylpyrrolidone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (57% by mass) are mixed to form a liquid composition. A product M was prepared, but the viscosity of the liquid composition M increased. The liquid composition M had a mode diameter of 11.5 μm and could not be discharged.

(Comparative Example 3)
Positive electrode active material 1 (30% by mass), carbon black (3% by mass), polyamide-imide (3% by mass), N-methylpyrrolidone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (64% by mass) are mixed to form a liquid composition. Object N was produced. The liquid composition N had a viscosity of 13.5 mPa · s and a mode diameter of 1.71 μm.

Using the liquid discharge device EV2500, the liquid composition N was discharged onto an aluminum foil as shown in FIG. 2 to obtain a positive electrode A. At this time, the aluminum foil was fixed on the hot plate and heated to 120 ° C. The liquid composition N had good discharge stability, and no discharge failure occurred. As a result, it was possible to form a positive electrode mixture layer having an active material amount of 1.9 mg / cm ^{2 per unit area, and the liquid composition N had good discharge efficiency.}

In the positive electrode A, the peel strength of the positive electrode mixture was 1.01 N, and the capacity per unit area was 0.24 mAh / cm ² .

(Comparative Example 4)
Positive electrode active material 1 (30% by mass), carbon black (3% by mass), and N-methylpyrrolidone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (67% by mass) were mixed to prepare a liquid composition N'. The liquid composition N'has a viscosity of 10.2 mPa · s and a mode diameter of 1.71 μm.

Using the liquid discharge device EV2500, the liquid composition N'was discharged onto an aluminum foil as shown in FIG. 2 to obtain a positive electrode A'. At this time, the aluminum foil was fixed on the hot plate and heated to 120 ° C. The liquid composition N'has good discharge stability and no discharge failure occurs. As a result, a positive electrode mixture layer having an active material amount of 1.9 mg / cm ² per unit area could be formed, and the liquid composition N'had good discharge efficiency.

Since the peel strength of the positive electrode mixture of the positive electrode A'was 0.002N, the capacity per unit area could not be measured.

Table 2 shows the evaluation results of the amount of active material per unit area, the peel strength of the electrode mixture layer, and the capacity of the electrode.

The abbreviations for liquids are as follows.
NMP: N-methylpyrrolidone DMA: N, N-dimethylacetamide

From Table 2, it can be seen that the electrodes of Examples 1 to 13 have a good amount of active material per unit area, peel strength of the electrode mixture layer, and electrode capacity, and have a high degree of freedom in design. For example, in the electrode of Example 11, since the amount of binder added is increased, the peel strength of the electrode mixture layer is high.

On the other hand, in Comparative Example 1, when the positive electrode A was prepared, a single liquid composition L containing ethyl lactate used in the liquid compositions A of Examples 1 to 4 and 11 was prepared. Gelled.

In Comparative Example 2, when the negative electrode B was prepared, a single liquid composition M containing NMP used in the liquid composition B of Example 10 was prepared, so that the viscosity increased.

In Comparative Example 3, the amount of active material per unit area of the electrode, the peeling strength of the electrode mixture layer, and the capacity of the electrode are good, but the degree of freedom in designing the liquid composition N is low.

In Comparative Example 4, since the liquid composition N'does not contain a binder, the peel strength of the electrode mixture layer is low.

1 Electrochemical element 10, 15 Negative electrode 11 Negative electrode base 12 Negative electrode mixture layer 12A First liquid composition 12B Second liquid composition 20, 25 Positive electrode 21 Positive electrode base 22 Positive electrode mixture layer 30 Separator 40 Electrode element 41, 42 Leader 51 Electrode layer 52 Exterior

Japanese Patent No. 5571304 Japanese Patent No. 5913780

Claims (9)

A liquid composition set used for forming a positive electrode mixture layer or a negative electrode mixture layer.
A first liquid composition in which the first electrode material is dissolved or dispersed in the first liquid,
It has a second liquid composition in which a second electrode material different from the first electrode material is dissolved or dispersed in a second liquid different from the first liquid.
The second electrode material is a liquid composition set that is more easily dissolved or dispersed in the second liquid than the first liquid. The liquid composition set according to claim 1, further comprising at least one of the first liquid composition and the second liquid composition. The liquid composition set according to claim 1 or 2, wherein the first liquid composition and the second liquid composition have a viscosity capable of being discharged from a liquid discharge head. The liquid composition set according to any one of claims 1 to 3, wherein the first electrode material contains a conductive auxiliary agent. At least one of the first electrode material and the second electrode material contains an active material and contains an active material.
The liquid composition set according to any one of claims 1 to 4, wherein the active material is a material capable of storing or releasing alkali metal ions. At least one of the first electrode material and the second electrode material contains an active material and contains an active material.
The liquid composition set according to any one of claims 1 to 4, wherein the liquid composition containing the active material has a content of the active material of 20% by mass or more. The liquid composition set according to any one of claims 1 to 6, wherein the first electrode material and the second electrode material have a maximum particle size smaller than the nozzle diameter of the liquid discharge head. The liquid composition set according to any one of claims 1 to 7, wherein the first electrode material and the second electrode material have a mode diameter of 3 μm or less. A method for producing an electrochemical element, which comprises a step of applying the liquid composition set according to any one of claims 1 to 8 onto an electrode substrate to form an electrode mixture layer.

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