阅读说明：本技术 电极复合材料用液体组合物，电极及电化学元件的制造方法 (Liquid composition for electrode composite material, electrode, and method for producing electrochemical element ) 是由 中岛聪 铃木荣子 栗山博道 鹰式启吾 大木本美玖 竹内重雄 升泽正弘 于 2020-01-06 设计创作，主要内容包括：本发明涉及电极复合材料用液体组合物,电极的制造方法,以及电化学元件的制造方法。本发明的目的在于,提供即使粘度低也能制造电极复合材料的剥离强度大的电极的电极复合材料用液体组合物。本发明的电极复合材料用液体组合物含有活性物质(A)、分散介质(B)及聚合性化合物(C),25℃的粘度为能从液体排出头排出的粘度。(The present invention relates to a liquid composition for an electrode composite material, a method for producing an electrode, and a method for producing an electrochemical device. The purpose of the present invention is to provide a liquid composition for an electrode composite material, which can produce an electrode having a high peel strength even when the viscosity is low. The liquid composition for an electrode composite material of the present invention contains an active material (a), a dispersion medium (B), and a polymerizable compound (C), and has a viscosity at 25 ℃ that enables discharge from a liquid discharge head.)

1. A liquid composition for an electrode composite, characterized in that:

comprises an active material, a dispersion medium and a polymerizable compound;

the viscosity at 25 ℃ is a viscosity that can be discharged from the liquid discharge head.

2. The liquid composition for an electrode composite material according to claim 1, wherein the viscosity at 25 ℃ is 50 mPas or less.

3. The liquid composition for an electrode composite according to claim 1 or 2, wherein the active material is a material capable of intercalating or deintercalating an alkali metal ion.

4. The liquid composition for an electrode composite material according to any one of claims 1 to 3, wherein the content of the active material is 20% by mass or more.

5. The liquid composition for an electrode composite according to any one of claims 1 to 4, wherein the maximum particle diameter of the active material is not more than the nozzle diameter of the liquid discharge head.

6. The liquid composition for an electrode composite according to any one of claims 1 to 5, wherein the mode diameter of the active material is 3 μm or less.

7. The liquid composition for an electrode composite according to any one of claims 1 to 6, wherein the dispersion medium contains a porogen.

8. A method of manufacturing an electrode, comprising:

a process for coating the liquid composition for an electrode composite material according to any one of claims 1 to 7 on an electrode substrate.

9. A method of manufacturing an electrochemical device, comprising:

a process for producing an electrode by using the method for producing an electrode according to claim 8.

Technical Field

The present invention relates to a liquid composition for electrode composite materials (liquid composition), a method for producing an electrode, and a method for producing an electrochemical device.

Background

Lithium ion secondary batteries are mounted in portable devices, hybrid vehicles, electric vehicles, and the like, and demand for such batteries is increasing. In addition, there is an increasing demand for thin batteries to be mounted on various wearable devices or medical patches, and the demand for lithium ion secondary batteries is diversified.

Conventionally, as a method for producing an electrode constituting a lithium ion secondary battery, a method for forming an electrode composite material on an electrode substrate by applying a liquid composition for an electrode composite material using a die coater, a comma coater, a reverse roll coater, or the like has been known.

The liquid composition for electrode composite materials generally contains an active material, a dispersion medium, and a binder, and the viscosity is increased because the binder is dissolved in the dispersion medium.

However, if a liquid composition for an electrode composite material having a high viscosity is used, there is a problem that productivity of an electrode is lowered.

In the examples of patent document 1, an electrode composition for inkjet printing is exemplified in which the content of a binder having a viscosity of 1 to 20cps in a 1 wt% aqueous solution is 0.01 to 0.5 wt%, and the viscosity is 3.1 to 5.8 cps.

However, when an electrode is produced using such an electrode composition for inkjet printing, there is a problem that the peel strength of an electrode composite material becomes small.

[ patent document 1] Japanese patent laid-open No. 2009-152180

Disclosure of Invention

The present invention has been made in view of the above problems, and an object of one embodiment of the present invention is to provide a liquid composition for an electrode composite material, which can produce an electrode having a high peel strength of the electrode composite material even when the viscosity is low.

In one embodiment of the present invention, a liquid composition for an electrode composite material contains an active material, a dispersion medium, and a polymerizable compound, and has a viscosity at 25 ℃ that enables discharge from a liquid discharge head.

The effects of the present invention are explained below:

according to one aspect of the present invention, a liquid composition for an electrode composite material can be provided which can produce an electrode having a high peel strength of the electrode composite material even when the viscosity is low.

Drawings

FIG. 1 is a schematic view showing an example of a liquid composition for an electrode composite material according to the present embodiment.

FIG. 2 is a schematic diagram showing an example of an electrode manufactured by the manufacturing method of the present embodiment.

Fig. 3 is a sectional view showing an example of the negative electrode of the present embodiment.

Fig. 4 is a schematic diagram illustrating an example of the method for manufacturing the negative electrode according to the present embodiment.

Fig. 5 is a schematic diagram showing another example of the method for producing a negative electrode according to the present embodiment.

Fig. 6 is a schematic view showing a modification of the liquid discharge apparatus shown in fig. 4 and 5.

Fig. 7 is a sectional view showing an example of the positive electrode of the present embodiment.

FIG. 8 is a sectional view showing an example of an electrode member used in the electrochemical device of the present embodiment.

FIG. 9 is a cross-sectional view showing an example of an electrochemical device used in the present embodiment.

Fig. 10 is a graph showing the relationship between the viscosity of the liquid compositions of the examples and comparative examples and the peel strength of the electrode composite material.

Detailed description of the preferred embodiments

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

< liquid composition for electrode composite >

The liquid composition for an electrode composite material (hereinafter referred to as "liquid composition") according to the present embodiment contains an active material a, a dispersion medium B, and a polymerizable compound C (see fig. 1), and may further contain a conductive assistant, a dispersant, and the like as needed.

The viscosity of the liquid composition of the present embodiment at 25 ℃ is not particularly limited as long as it can be discharged from the liquid discharge head, and is preferably 50mPa · s or less. When the viscosity at 25 ℃ of the liquid composition of the present embodiment is 50mPa · s or less, the particle size distribution of the liquid composition of the present embodiment is less likely to change, and therefore, the discharge stability of the liquid composition of the present embodiment is improved.

The viscosity of the liquid composition of the present embodiment at 25 ℃ is preferably 9.5 mPas or more. When the viscosity at 25 ℃ of the liquid composition of the present embodiment is 9.5mPa · s or more, the liquid composition of the present embodiment is easily discharged as droplets, and therefore the discharge amount is easily controlled.

Here, the liquid composition of the present embodiment can be used for manufacturing an electrode for manufacturing an electrochemical device.

The electrodes of the electrochemical element are disposed on both sides of the insulator, and store electric energy.

< active substance >

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

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

The positive electrode active material is not particularly limited as long as it can insert (occlude) or release (release) an alkali metal ion, and an alkali metal-containing transition metal compound can be used.

Examples of the alkali metal-containing transition metal compound include lithium-containing transition metal compounds such as a composite oxide containing lithium and at least one element selected from the group consisting of cobalt, manganese, nickel, chromium, iron, and vanadium.

Examples of the lithium-containing transition metal compound include lithium cobaltate, lithium nickelate, and lithium manganate.

As the transition metal compound containing an alkali metal, a compound having XO in the crystal structure thereof can also be used₄Polyanionic tetrahedral compounds (X ═ P, S, As, Mo, W, Si, etc.). Among these, lithium-containing transition metal phosphate compounds such as lithium iron phosphate and lithium vanadium phosphate are preferable from the viewpoint of recycling characteristics, and lithium vanadium phosphate is particularly preferable from the viewpoint of lithium diffusion coefficient and output characteristics.

The polyanionic compound is preferably compounded by coating the surface with a conductive aid such as a carbon material in terms of electron conductivity.

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

Examples of the carbon material include natural graphite, artificial graphite, hard graphitizable carbon (hard carbon), and easy graphitizable carbon (soft carbon).

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

In addition, from the viewpoint of energy density of the electrochemical device, it is preferable to use a high capacity material such as silicon, tin, a silicon alloy, a tin alloy, silicon oxide, silicon nitride, and tin oxide as the negative electrode active material.

The maximum particle diameter of the active material is preferably not larger than the nozzle diameter of the liquid discharge head. This improves the discharge stability of the liquid composition of the present embodiment.

The Mode diameter (maximum frequency diameter) of the active substance is preferably 3 μm or less, more preferably 1 μm or less. When the mode diameter of the active material is 3 μm or less, the storage stability of the liquid composition is improved.

The mode diameter of the active material is preferably 0.5 μm or more.

10% diameter (D) of active substance₁₀) Preferably 0.1 μm or more, more preferably 0.15 μm or more. Active substance D₁₀When the particle size is 0.1 μm or more, the storage stability of the liquid composition is improved.

Active substance D₁₀Preferably 0.8 μm or less.

The content of the active material in the liquid composition of the present embodiment is preferably 20% by mass or more, and more preferably 25% by mass or more. When the content of the active material in the liquid composition of the present embodiment is 20% by mass or more, the capacity of the electrochemical device is improved.

The content of the active material in the liquid composition of the present embodiment is preferably 50% by mass or less.

< dispersing Medium >

The dispersion medium is not particularly limited as long as the active material can be dispersed therein, and examples thereof include aqueous dispersion media such as water, ethylene glycol and propylene glycol, and organic dispersion media such as N-methyl-2-pyrrolidone, cyclohexanone, butyl acetate, trimethylbenzene, 2-N-butoxymethanol, 2-dimethylethanol and N, N-dimethylacetamide.

The dispersion medium preferably contains a porogen (porogen). Thereby, a void communicating with the electrode composite material can be formed. As a result, the nonaqueous electrolyte solution of the electrode composite material is improved in retention property, and ion diffusion is facilitated, so that an electrochemical element having a large capacity per unit area of the electrode can be obtained.

The porogen is not particularly limited as long as the polymerizable compound is dissolved and the polymerizable compound is polymerized, and the polymer of the polymerizable compound is phase-separable, and examples thereof include glycol monoethers such as dipropylene glycol monomethyl ether (DPGME), diethylene glycol monomethyl ether (DEGME), and ethylene glycol monobutyl ether (EGBE), esters such as γ -butyrolactone and propylene carbonate, and amides such as N, N-dimethylacetamide.

The dispersion medium may be used alone, or two or more kinds may be used in combination.

< polymerizable Compound >

The polymerizable compound is preferably used in combination with a polymerization initiator or catalyst.

The polymerizable compound may be either monofunctional or polyfunctional.

Here, the term "monofunctional" means having one polymerizable group, and the term "multifunctional" means having at least two 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, infrared rays, and the like, and examples thereof include acrylic esters, methacrylic esters, amino acrylate resins, vinyl ester resins, unsaturated polyesters, epoxy resins, oxetane resins, vinyl ethers, resins utilizing an ene-thiol reaction, and the like. Among them, acrylic ester, methacrylic ester, amino acrylic ester resin, and vinyl ester resin are preferable from the viewpoint of productivity.

Multifunctional acrylates can be used as michael acceptors and, therefore, can allow for the re-addition reaction with michael donors.

Examples of the polyfunctional acrylate include difunctional acrylates such as low molecular weight compounds including dipropylene glycol diacrylate and neopentyl glycol diacrylate, and high molecular weight compounds including polyethylene glycol diacrylate, urethane acrylate and epoxy acrylate; trifunctional acrylates such as trimethylolpropane acrylate and pentaerythritol triacrylate; and tetra-or higher-functional acrylates such as pentaerythritol tetraacrylate and pentaerythritol hexaacrylate.

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

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

Examples of the thiol include 1, 2-ethanedithiol, 1, 3-propanedithiol, 1, 4-butanedithiol, 2, 3-butanedithiol, 1, 5-pentanethiol, 1, 6-hexanedithiol, 1, 2-benzenedithiol, 1, 3-benzenedithiol, 1, 4-benzenedithiol, 1,3, 5-benzenetrithiol, and 4, 4-biphenyldithiol.

As the catalyst for the heavy addition reaction, a catalyst generally used in the Michael addition reaction can be appropriately selected and used, and examples thereof include amine catalysts such as Diazabicycloundecene (DBU) and N-methyldicyclohexylamine, base catalysts such as sodium methoxide, sodium ethoxide, potassium tert-butoxide, sodium hydroxide and tetramethylammonium hydroxide, and metallic sodium and butyllithium.

Examples of the polymerizable compound capable of addition polymerization (radical polymerization) include ester compounds obtained by epoxidizing a double bond of a terpene having an unsaturated bond such as myrcene, carene, ocimene, pinene, limonene, camphene, isoperpinene, tricyclene, terpinene, fenchene, phellandrene, abietane, sabinene, dipentene, bornene, isoprenol (isopregol), carvone, and the like, and acrylic acid or methacrylic acid. Or an alcohol derived from terpene and acrylic acid or methacrylic acid, and examples of the alcohol include citronellol, pinocenol, geraniol, benzyl alcohol (phenotyl alcohol), nerol, borneol, linalool, menthol, terpineol, thujol, citronellal (citronellal), irisone, irilone, citrulline, citral, pinolene, cyclocitral, carvyl ketone, ascaridol, crocetin, piperitol (pi, perithol), menthene mono-ol (menthone mono), dihydrocarvone, carveol, sclareol, manolol, hinokitiol, ferulol, ruitolene, sequol, farnesol, patchouli alcohol, nerolidol, carotenol, pindolol, santalol (santalol), eucalyptol, patchoulol, and the like. Further, an acrylate or methacrylate compound having the following skeleton in the ester side chain can be exemplified. Such as citronellal, hinokitiol, santaloic acid, menthone, dill-chrysanthenone, phellandral, heptanedione, perillaldehyde (peryl aldehyde), thujone, carene, marigold ketone, camphor, bisabolene, santalene, zingiberene, caryophyllene, curcumene, cedrene, juniperbene, longifolene, sesquibenenilene, cedrol, guaiol, valerian glycol, cyperolone, erimomenone, zerumenone, campholelene, roheparene, milene, pulegalene, totalene, ketomeino oxide, tear arborvitae, abietic acid, pimaric acid, levopimaric acid, iso-d-pimaric acid, kaempferic acid, gadoleic acid, carotenoids, pilolaldehyde (pelargyl aldehyde), menthone, fennel, fenchylene, sesquiterpenes, diterpenes, triterpenes, and the like.

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

As the photopolymerization initiator, a photo radical generator can be used.

Examples of the optical radical generator include compounds such as α -hydroxy or α -aminoacetophenone, 4-aroyl-1, 3-dioxocyclopentyloxy, benzyl ketal, 2, 2-diethoxyacetophenone, p-dimethylaminoacetophenone, p-dimethylaminopropiophenone, benzophenone, 2-chlorobenzophenone, pp ' -dichlorobenzophenone, pp ' -bisdiethylaminobenzophenone, Michler's ketone, benzil, benzoin, benzyl dimethyl ketal, tetramethylthiuram monosulfide, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, azobisisobutyronitrile, benzoin peroxide, di-tert-butyl peroxide, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1-one, methylbenzoyl methyl ester, isopropylbenzoin ether, benzoin methyl ether, benzoin ethyl ether, benzyl ether, benzoin ether, dihalo-2-hydroxy-2-methylpropane-1-one, bis (4-propyl) -2-hydroxy-2-methyl-2-methyl-1-ketone, 2-methyl-1-one, 2-methyl benzoylmethyl ether, 2-methyl-2-propyl-2-methyl-1-methyl-2-methyl-1-one, 2-methyl-phenyl-methyl-2-methyl-phenyl-2-one, 2-methyl-2-methyl-ethyl ether, 2-ethyl-methyl-ethyl-2-methyl-2-ethyl-2-methyl-2-methyl-ethyl-2-methyl-ethyl-methyl-2-ethyl-2-methyl-ethyl-methyl-2-methyl-2-methyl-ethyl-methyl-ethyl-2-methyl-2-methyl-phenyl-one, 2-methyl-ethyl-phenyl-methyl-ethyl-methyl-phenyl-2-ethyl-2.

Further, a photo-crosslinking type radical generator such as a bisazide compound (e.g., 2' -azobis (2, 4-methylpentanonitrile)) and a photo-radical generator may be used in combination.

Examples of the thermal polymerization initiator include Azobisisobutyronitrile (AIBN).

As the polymerization initiator, a photoacid generator can also be used. At this time, if 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 to be polymerized in the presence of an acid include compounds having a cyclic ether group such as an epoxy group, an oxetane group and the like, propylene or ethylene compounds having the above substituent in a side chain, carbonate compounds, low molecular weight melamine compounds, vinyl ethers, vinyl carbazoles, styrene derivatives, α -methylstyrene derivatives, vinyl alcohol esters mainly composed of an ester compound of vinyl alcohol, propylene, methacrylic or the like, and monomers having a vinyl bond capable of polymerizing cations, which can be used in combination.

Examples of the photoacid generator include onium salts, diazonium salts (diazonium salt), quinone diazide compounds, organic halides, aromatic sulfonic acid ester compounds, disulfonic acid compounds, sulfonyl compounds, sulfonic acid ester compounds, sulfonium compounds, sulfonamide compounds, iodonium compounds, and sulfonyl diazomethane compounds. Among them, onium salts are preferably used.

Examples of the onium salt include diazonium salts, phosphonium salts, and sulfonium salts each having a fluoroborate anion, hexafluoroantimonate anion, hexafluoroarsenate anion, trifluoromethanesulfonate anion, p-toluenesulfonate anion, and p-nitrotoluenesulfonate anion as a counter ion.

Further, the photoacid generator may be used even if a triazine halide compound is used.

The photoacid generators may be used alone, or two or more of them may be used in combination.

When a photoacid generator is used, a sensitizing dye may be used in combination.

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

< conductive assistant >

As the conductive assistant, for example, carbon materials such as conductive carbon black, carbon nanofibers, carbon nanotubes, graphene, and graphite particles produced by a furnace method, an acetylene method, a gasification method, or the like can be used.

As the conductive aid other than the carbon material, for example, metal particles such as aluminum, metal fibers, or the like can be used.

The conductive aid may be previously compounded with the active material.

The mass ratio of the conductive auxiliary to the active material is preferably 10% or less, and more preferably 8% or less. When the mass ratio of the conductive auxiliary agent to the active material is 10% or less, the stability of the liquid composition for an electrode composite material of the present embodiment is improved. When the mass ratio of the conductive auxiliary agent to the active material is 8% or less, the stability of the liquid composition for an electrode composite material of the present embodiment is further improved.

< dispersant >

The dispersant is not particularly limited as long as it can improve the dispersibility of the active material and the conductive aid in the dispersion medium, and examples thereof include polycarboxylic acid dispersants, naphthalenesulfonate polycondensation dispersants, polyethylene glycols, polycarboxylic acid partial alkyl ester dispersants, polyether dispersants, polymeric dispersants such as polyalkylene polyamine dispersants, alkylsulfonic acid dispersants, 4-stage ammonium salt dispersants, higher alcohol alkylene oxide dispersants, polyol ester dispersants, surface active agent dispersants such as alkyl polyamine dispersants, and inorganic dispersants such as polyphosphate dispersants.

< method for producing electrode >

The method for producing an electrode according to the present embodiment includes a step of applying the liquid composition according to the present embodiment to an electrode substrate.

The method of applying the liquid composition is not particularly limited, and examples thereof include a spin coating method, a doctor blade 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, a slit 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 discharge printing method. Among them, the liquid discharge printing method is particularly preferable from the viewpoint of productivity of the electrode.

After the liquid composition of the present embodiment is applied to the electrode substrate D, the polymerizable compound C is polymerized by heating or irradiation with non-ionizing radiation, infrared rays, or the like, and the binder C' is formed (see fig. 2).

The material constituting the electrode substrate (collector) is not particularly limited as long as it has conductivity and is stable against an applied potential.

< negative electrode >

Fig. 3 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 surface of a negative electrode substrate 11.

The negative electrode composite material layer 12 may be formed on both surfaces of the negative electrode base 11.

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

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

< method for producing negative electrode >

Fig. 4 shows an example of a method for manufacturing the negative electrode according to the present embodiment.

The method for producing the negative electrode 10 includes a step of discharging a liquid composition 12A for the negative electrode composite material layer 12 (hereinafter, referred to as a liquid composition 12A) onto the negative electrode base 11 using a liquid discharge apparatus 300.

Here, the liquid composition 12A contains a negative electrode active material, a dispersion medium, and a polymerizable compound, and has a viscosity at 25 ℃ that enables discharge from the liquid discharge head 306.

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

Further, when the liquid composition 12A is not discharged from the liquid discharge head 306, the liquid discharge apparatus 300 may be provided with a mechanism for capping the nozzles in order to prevent drying.

In the production of the negative electrode 10, the negative electrode substrate 11 is placed on a heatable table 400, and then droplets of the liquid composition 12A are discharged to the negative electrode substrate 11 and heated. At this time, the stage 400 may be moved, and the liquid discharge head 306 may also be moved.

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

The heating means is not particularly limited as long as it is not in direct contact with the liquid composition 12A, and examples thereof include a resistance heater, an infrared heater, a fan heater, and the like.

The heating mechanism may be provided in plurality.

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

In addition, the liquid composition 12A discharged to the negative electrode substrate 11 may be irradiated with ultraviolet light while being heated.

Fig. 5 shows another example of the method for manufacturing the negative electrode according to the present embodiment.

The method for producing the negative electrode 10 includes a step of discharging the liquid composition 12A onto the negative electrode substrate 11 using the liquid discharge apparatus 300.

First, an elongated negative electrode substrate 11 is prepared. Then, the negative electrode substrate 11 is wound around a cylindrical core so that the side where the negative electrode mixture layer 12 is formed becomes the upper side in the drawing, and is set on the feed-out roller 304 and the winding roller 305. Here, the feed roller 304 and the take-up roller 305 rotate counterclockwise, and the negative electrode substrate 11 is conveyed from the right side to the left side in the figure. Then, droplets of the liquid composition 12A are discharged (ejected) onto the transported negative electrode substrate 11 from a liquid discharge head 306 disposed above the negative electrode substrate 11 between the delivery roller 304 and the take-up roller 305. Droplets of the liquid composition 12A are discharged to cover at least a part of the anode base 11.

The liquid discharge heads 306 may be provided in plural in a direction substantially parallel or substantially perpendicular to the conveyance direction of the negative electrode base 11.

Next, the negative electrode substrate 11 from which the liquid composition 12A is discharged is conveyed to the heating mechanism 309 by the delivery roller 304 and the take-up roller 305. As a result, the polymerizable compound contained in the liquid composition 12A on the negative electrode substrate 11 is polymerized to form the negative electrode composite material layer 12, and the negative electrode 10 is obtained. After that, the negative electrode 10 is cut into a desired size by punching or the like.

The heating means 309 is not particularly limited as long as it does not directly contact the liquid composition 12A, and examples thereof include a resistance heater, an infrared heater, and a fan heater.

The heating means 309 may be provided on either the upper or lower side of the negative electrode base 11, or a plurality of heating means may be provided.

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

In addition, the liquid composition 12A discharged to the negative electrode substrate 11 may be irradiated with ultraviolet light while being heated.

Fig. 6 shows a modification of the liquid discharge apparatus 300.

The liquid discharge apparatus 300' can circulate the liquid composition 12A through the liquid discharge head 306, the tank 307, and the pipe 308 by controlling the pump 310 and the valves 311 and 312.

Further, the liquid discharge apparatus 300' may be provided with an external tank 313, and when the liquid composition 12A in the tank 307 decreases, the liquid composition 12A may be supplied from the external tank 313 to the tank 307 by controlling the pump 310 and the valves 311, 312, and 314.

By using the liquid discharge apparatuses 300 and 300', the liquid composition 12A can be discharged to a target position of the negative electrode substrate 11. In addition, when the liquid discharge apparatuses 300 and 300' are used, the surfaces of the negative electrode substrate 11 and the negative electrode mixture layer 12 which are in contact with each other in the vertical direction can be bonded to each other. Further, if the liquid discharge devices 300 and 300' are used, 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 composite material layer 22 is formed on one surface of a positive electrode substrate 21.

The positive electrode composite material layer 22 may be formed on both surfaces of the positive electrode base 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, and tantalum.

< method for producing Positive electrode >

The positive electrode 20 is produced by the same method as the negative electrode 10, except that the liquid composition for the positive electrode mixture layer 22 is discharged onto the positive electrode base 21.

Here, the liquid composition for the positive electrode composite material layer 22 contains the positive electrode active material, the dispersion medium, and the polymerizable compound, and has a viscosity at 25 ℃ that can be discharged from the liquid discharge head.

< method for producing electrochemical device >

The method for manufacturing an electrochemical device according to the present embodiment includes a step of manufacturing an electrode using the method for manufacturing an electrode according to the present embodiment.

< electrode element >

Fig. 8 shows an example of an electrode element used in the electrochemical device according to the present embodiment.

The negative electrode 15 and the positive electrode 25 of the electrode element 40 are laminated via a separator 30. Here, the positive electrode 25 is laminated on both sides of the negative electrode 15. The lead 41 is connected to the negative electrode base 11, and the lead 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 composite material layers 12 are formed on both surfaces of the negative electrode base 11.

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

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

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

< spacers >

Separator 30 is provided between negative electrode 15 and positive electrode 25 as necessary to prevent short-circuiting between negative electrode 15 and positive electrode 25.

Examples of the separator 30 include paper such as kraft paper, vinylon mixed paper, and synthetic pulp mixed paper, polyolefin nonwoven fabric such as cellophane, polyethylene graft film, and polypropylene meltblown nonwoven fabric, polyamide nonwoven fabric, glass fiber nonwoven fabric, and microporous film.

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

The spacer 30 may have a single-layer structure or a stacked-layer structure.

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

< electrochemical device >

Fig. 9 shows an example of an electrochemical device according to the present embodiment.

In the electrochemical element 1, an electrolyte aqueous solution or a nonaqueous electrolyte is injected into the electrode element 40 to form an electrolyte layer 51, and the electrolyte layer is sealed by a package 52. In the electrochemical element 1, the leads 41 and 42 are drawn out of the outer package 52.

The electrochemical element 1 may have other components as needed.

The electrochemical element 1 is not particularly limited, and examples thereof include an aqueous storage element, a nonaqueous storage element, and the like.

The shape of the electrochemical element 1 is not particularly limited, and examples thereof include a laminate type, a cylinder type in which the sheet-like electrode and the separator are formed in a spiral shape, a cylinder type in which the particle electrode and the separator are combined and have an internal-exit structure, and a coin type in which the particle electrode and the separator are laminated.

< aqueous electrolyte solution >

Examples of the electrolyte salt constituting the aqueous electrolyte solution include sodium hydroxide, potassium hydroxide, sodium chloride, potassium chloride, ammonium chloride, zinc acetate, zinc bromide, zinc iodide, zinc tartrate, and zinc perchlorate.

< nonaqueous electrolyte >

As the nonaqueous electrolyte, a solid electrolyte or a nonaqueous electrolytic solution can be used.

Here, the nonaqueous electrolytic solution is an electrolytic solution in which an electrolyte salt is dissolved in a nonaqueous solvent.

< non-aqueous solvent >

The nonaqueous solvent is not particularly limited and may be appropriately selected depending on the purpose, but is preferably an aprotic organic solvent.

As the aprotic organic solvent, a carbonate-based organic solvent such as a chain carbonate or a cyclic carbonate can be used. Among them, chain carbonates are preferable in view of high dissolving power of the electrolyte salt.

The aprotic organic solvent preferably has a low viscosity.

Examples of the chain carbonate include dimethyl carbonate (DMC), diethyl carbonate (DEC), and Ethyl Methyl Carbonate (EMC).

The content of the chain carbonate in the nonaqueous solvent is not particularly limited and may be appropriately selected according to the purpose, but is preferably 50% by mass or more. When the chain carbonate content in the nonaqueous solvent is 50 mass% or more, the content of cyclic substances is reduced even when the nonaqueous solvent other than the chain carbonate is a cyclic substance having a high dielectric constant (for example, a cyclic carbonate or a cyclic ester). Therefore, even when a nonaqueous electrolytic solution having a high concentration of 2M or more is prepared, the viscosity of the nonaqueous electrolytic solution is lowered, and the permeation of the nonaqueous electrolytic solution into the electrode and the ion diffusion become favorable.

Examples of the cyclic carbonate include Propylene Carbonate (PC), Ethylene Carbonate (EC), Butylene Carbonate (BC), Vinylene Carbonate (VC), and the like.

As the nonaqueous solvent other than the carbonate-based organic solvent, for example, ester-based organic solvents such as cyclic esters and chain esters, ether-based organic solvents such as cyclic ethers and chain ethers, and the like can be used.

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

Examples of the chain ester include alkyl propionate, dialkyl malonate, alkyl acetate (e.g., Methyl Acetate (MA), ethyl acetate, etc.), alkyl formate (e.g., Methyl Formate (MF), ethyl formate, etc.), and the like.

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

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

< electrolyte salt >

The electrolyte salt is not particularly limited as long as it has high ionic conductivity and can be dissolved in a nonaqueous solvent.

The electrolyte salt preferably contains a halogen atom.

Examples of the cation constituting the electrolyte salt include lithium ions.

Examples of the anion constituting the electrolyte salt include BF₄ ^-、PF₆ ^-、AsF₆ ^-、CF₃SO₃ ^-、(CF₃SO₂)₂N^-、(C₂F₅SO₂)₂N^-And the like.

The lithium salt is not particularly limited and may be appropriately selected according to the purpose, and for example, lithium hexafluorophosphate (L iPF) may be mentioned₆) Lithium fluoride (L iBF)₄) Lithium arsenic hexafluoride (L iAsF)₆) Lithium trifluoromethanesulfonate (L iCF)₃SO₃) Lithium bis (trifluoromethylsulfonyl) imide (L iN (CF)₃SO₂)₂) Lithium bis (pentafluoroethylsulfonyl) imide (L iN (C)₂F₅SO₂)₂) Among them, L iPF is preferable from the viewpoint of ion conductivity₆From the viewpoint of stability, L iBF is preferable₄。

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

The concentration of the electrolyte salt in the nonaqueous electrolytic solution can be appropriately selected according to the purpose, but is preferably 1 mol/L to 2 mol/L when the electrochemical element is of the swing type, and preferably 2 mol/L to 4 mol/L when the electrochemical element is of the standby type.

< use of electrochemical element >

The use of the electrochemical element is not particularly limited, and the electrochemical element can be used in various applications, for example, a notebook computer, a pen input computer, a mobile computer, an electronic book player, a mobile phone, a mobile facsimile, a portable copier, a portable printer, a headphone stereo, a video camera, a liquid crystal television, a portable cleaner, a portable CD, a mini disk, a transceiver, an electronic organizer, a calculator, a memory card, a portable tape recorder, a radio, a backup power source, a motor, a lighting device, a toy, a game device, a clock, a flash lamp, a camera, and the like.