Manufacturing method of lamination body and manufacturing method of electrochemical element

Abstract

To provide a lamination body capable of obtaining an electrochemical element with an excellent input and output characteristic.SOLUTION: A manufacturing method of a lamination body is a manufacturing method of a lamination body having: an electrode mixture layer containing a solid electrolyte for the electrode mixture layer and an electrode active material; and a solid electrolyte layer that contains a solid electrolyte for the solid electrolyte layer formed on the electrode mixture layer. The manufacturing method of the lamination body, comprises: a pre-application solid electrolyte layer formation step of forming a pre-application solid electrolyte layer including application of a liquid composition containing a component of the solid electrolyte layer onto the pre-application electrode mixture layer; and a compression step of compressing the pre-application lamination body that is obtained in the pre-application solid electrolyte layer formation step. The solid electrolyte for the solid electrolyte layer contains a sulfur element. A volume density of the pre-application electrode mixture layer to which the liquid composition is applied in the pre-application solid electrolyte layer formation step is 1.2 to 2.1 g / cm3.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a laminate and a method for manufacturing an electrochemical element.

Background Art

[0002] Electrochemical elements such as lithium-ion secondary batteries, lithium-ion capacitors, electric double-layer capacitors, and redox capacitors are mounted on electronic devices, electric vehicles, etc. and are widely used. In particular, the demand for in-vehicle lithium-ion secondary batteries is expected to increase in recent years against the background of the need for low environmental impact. Under such circumstances, further improvement in the safety and energy density of lithium-ion secondary batteries is required, and efforts are being made to put all-solid-state lithium secondary batteries using solid electrolytes instead of existing electrolytes into practical use.

[0003] For example, a composite in which a positive electrode material layer having an electrode density of 2.2 g / cm 3 after drying and pressing, sulfide-based solid electrolyte particles having an average particle diameter of 10 μm, and alumina particles having an average particle diameter of 0.1 μm are mixed at a volume ratio of 1:1 is hot-pressed and molded to produce a solid electrolyte layer, and a technique for laminating them has been proposed (see, for example, Patent Document 1).

[0004] In addition, a technique has been proposed in which a sheet composed of a positive electrode current collector member, an adhesive layer, and a positive electrode layer is rolled using a roll press to produce a positive electrode structure having an electrode density of 1.53 to 2.96 g / cc, and the positive electrode structure filled on the back surface of the electrolyte layer is pressurized to manufacture a solid battery (see, for example, Patent Document 2).

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to provide a laminate from which an electrochemical element having excellent input / output characteristics can be obtained.

Means for Solving the Problems

[0006] The manufacturing method of the laminate according to the present invention is a manufacturing method of a laminate having an electrode composite layer containing a solid electrolyte for the electrode composite layer and an electrode active material, and a solid electrolyte layer containing a solid electrolyte for the solid electrolyte layer formed on the electrode composite layer, including applying a liquid composition containing the components of the solid electrolyte layer on the electrode composite layer before pressurization, a pre-pressurization solid electrolyte layer forming step of forming a pre-pressurization solid electrolyte layer, and a pressurization step of pressurizing the pre-pressurized laminate obtained in the pre-pressurization solid electrolyte layer forming step, wherein the solid electrolyte for the solid electrolyte layer contains sulfur element, and the volume density of the pre-pressurized electrode composite layer to which the liquid composition is applied in the solid electrolyte layer forming step is 1.2 to 2.1 g / cm 3 is as follows.

Effects of the Invention

[0007] An object of the present invention is to provide a laminate from which an electrochemical element having excellent input / output characteristics can be obtained.

Brief Description of the Drawings

[0008]

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Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described. Note that the technical scope of the present invention is not limited by the best mode for carrying out the invention.

[0010] <Manufacturing Method of Laminate> The manufacturing method of the laminate according to the present embodiment is a manufacturing method of a laminate having an electrode mixture layer containing a solid electrolyte for an electrode mixture layer and an electrode active material, and a solid electrolyte layer containing a solid electrolyte for a solid electrolyte layer formed on the electrode mixture layer. The laminate can be used for an electrode applicable to an electrochemical element.

[0011] <<Electrode>> The electrode used in the laminate has an electrode substrate and an electrode mixture layer formed on the electrode substrate. Also, the electrode used in the laminate may be either a positive electrode or a negative electrode.

[0012] <<<Electrode Substrate>>> The electrode substrate is also referred to as a current collector. The material constituting the electrode substrate is not particularly limited, but a plate-like body, a foil-like body, etc. made of copper, nickel, stainless steel, indium, lithium, magnesium, titanium, iron, cobalt, zinc, aluminum, germanium, or an alloy thereof, etc. are preferable, and it can also be used as the electrode layer.

[0013] <<Electrode composite material layer>> The electrode composite material layer contains at least a solid electrolyte for the electrode composite material layer and an electrode active material. When the electrode used in the laminate is a positive electrode, the electrode composite material layer is a positive electrode composite material layer, and when the electrode used in the laminate is a negative electrode, the electrode composite material layer is a negative electrode composite material layer. Further, when the electrode used in the laminate is a positive electrode, the electrode active material is a positive electrode active material, and when the electrode used in the laminate is a negative electrode, the electrode active material is a negative electrode active material.

[0014] -Positive electrode composite material layer- The film thickness of the positive electrode composite material layer is not particularly limited, but it is preferably 10 to 500 μm. Also, regarding the weight ratio of the positive electrode active material and the solid electrolyte for the electrode composite material layer in the positive electrode composite material layer, although not particularly limited, it is preferably contained at a content rate in the range of 20:80 to 90:10.

[0015] -Negative electrode composite material layer- The film thickness of the negative electrode composite material layer is not particularly limited, but it is preferably 5 to 500 μm. Also, regarding the weight ratio of the negative electrode active material and the solid electrolyte for the electrode composite material layer in the negative electrode composite material layer, although not particularly limited, it is preferably contained at a content rate in the range of 20:80 to 90:10.

[0016] <<Electrode composite material layer forming process>> The manufacturing method of the laminate according to this embodiment includes an electrode composite material layer forming process. In the electrode composite material layer forming process, before the solid electrolyte layer forming process before pressurization described later, the electrode composite material layer is formed from a liquid composition containing the components of the electrode composite material layer.

[0017] The method for forming the electrode composite material layer is not particularly limited. For example, it is preferable to apply a liquid composition containing the material of the electrode composite material layer onto the electrode substrate by a wet coating process using a die coater, comma coater, or the like. Also, from the perspective of on-demand, it is preferable to form the electrode composite material layer by discharging a liquid composition containing the material of the electrode composite material layer with an inkjet head using the liquid discharge device described later (hereinafter referred to as the inkjet method).

[0018] Also, when forming the electrode composite material layer with a conventional die coater, comma coater, or the like, unevenness is likely to occur in the electrode composite material layer. On the other hand, when forming the electrode composite material layer by the inkjet method, unevenness is less likely to occur in the electrode composite material layer, the film thickness of the electrode composite material layer becomes uniform, and the interfacial resistance with the solid electrolyte layer formed later can be reduced.

[0019] <<Liquid Composition for Forming Electrode Composite Material Layer>> The liquid composition for forming the electrode composite material layer contains a dispersion medium, a solid electrolyte for the electrode composite material layer, and components of the electrode active material, and may contain components such as a dispersant and a binder as necessary.

[0020] -Dispersion Medium- The dispersion medium is not particularly limited and can be appropriately selected according to the purpose. However, it is preferably a dispersion medium having a relative permittivity at 25°C of 7.0 or less, more preferably 6.5 or less, and even more preferably 6.0 or less.

[0021] When the relative permittivity at 25°C is a dispersion medium of 7.0 or less, it is preferable in that the dispersibility of the solid electrolyte for the electrode composite material layer in the dispersion medium can be increased. Also, when the relative permittivity at 25°C is a dispersion medium of 7.0 or less, when used in combination with the solid electrolyte for the electrode composite material layer containing the sulfur element described later, the reaction between the dispersion medium and the solid electrolyte for the electrode composite material layer containing the sulfur element described later is less likely to occur, and as a result, it is preferable in that the generation of toxic hydrogen sulfide can be suppressed.

[0022] The dispersion medium may be used alone or in combination of two or more. When using a mixed dispersion medium in which two or more dispersion media are combined, it is preferable that the relative permittivity of the mixed dispersion medium is 7.0 or less at 25°C.

[0023] The method for measuring the relative permittivity of the dispersion medium is not particularly limited and can be appropriately selected according to the purpose. For example, it can be measured by performing double cylindrical tube current measurement at 10 kHz using a liquid permittivity meter (manufactured by Sanyo Trading Co., Ltd., Model 871).

[0024] Specific examples of the dispersion medium having a relative permittivity of 7.0 or less at 25°C include, for example, pentane, isopentane, hexane, heptane, 2,2-dimethylbutane, octane, cyclohexane, tetradecane, 1,4-dioxane, benzene, xylene, carbon tetrachloride, mesitylene, toluene, dibutyl ether, anisole, 1,2-diethoxyethane, 2-methylanisole, 3-methylanisole, 4-methylanisole, 1,2-methoxybenzene, 1,3-methoxybenzene, p-ethylaniline, 4-octanol, phenetole, 2-ethylhexyl acetate, butyl phenyl ether, isopropylbenzene, 1,2,3,4-tetrahydronaphthalene, ethyl decanoate, isobutyl acetate, diisopentyl ether, tridecane, cyclooctane, ethyl propionate, cymene, and the like.

[0025] It is preferable to use a dehydrated dispersion medium. The degree of dehydration is not particularly limited and can be appropriately selected according to the purpose. However, the water content measured by a Karl Fischer moisture concentration meter is preferably 1,000 ppm or less, more preferably 100 ppm or less, and even more preferably 10 ppm or less.

[0026] <<Solid Electrolyte for Electrode Binder Layer>> The solid electrolyte for the electrode composite layer is a solid electrolyte contained in the electrode composite layer. The solid electrolyte for the electrode composite layer is not particularly limited, but is preferably a solid electrolyte containing a sulfur element. The solid electrolyte containing a sulfur element is, for example, a solid electrolyte containing a sulfide (hereinafter referred to as a sulfide solid electrolyte).

[0027] Sulfide solid electrolytes can be broadly classified into crystalline sulfide solid electrolytes and glassy solid electrolytes. These sulfide solid electrolytes are not particularly limited as long as they have no electronic conductivity and have ionic conductivity. Furthermore, sulfide solid electrolytes are preferable in that they have high plasticity and can form a good interface between solid electrolyte particles or between a solid electrolyte and an active material. A sulfide solid electrolyte may be used alone or in combination of two or more.

[0028] The crystalline sulfide solid electrolyte is not particularly limited and can be appropriately selected according to the purpose. For example, Li 9.54 Si 1.74 P 1.44 S 11.7 C 10.3 、Li 9.6 P3S 12 、Li9P3S9O3、Li 9.81 Sn 0.81 P 2.19 S 12 、Li 9.42 Si 1.02 P 2.1 S 9.96 O 2.04 、Li 10 Ge(P 1-x Sb x )2S 12 (0≦x≦0.15), Li 10 SnP2S 12 、Li 10.35 [M1 1-x M 2x 1.35 P 1.65 S 12 (M1 and M2 are any of Si, Ge, Sn, As, and Sb), 0≦x≦0.15), Li 11 Si2PS 12 、Li 11 AlP2S​12 、 Li 3.45 Si 0.45 P 0.55 S4, Li6PS 5X (X is any one of Cl, Br, and I), Li5PS4X2 (X is any one of Cl, Br, and I), Li 5.5 PS 4.5 Cl 1.5 、 Li 5.35 Ca 0.1 PS 4.5 Cl 1.55 、 Li 6+x M x Sb 1-x S5I (M is any one of Si, Ge, and Sn, 0 ≦ x ≦ 1), Li7P2S8I, γ-Li3PS4, Li4MS4 (M is any one of Ge, Sn, and As), Li 4-x Sn 1-x Sb x S4 (0 ≦ x ≦ 0.15), Li 4-x Ge 1-x P x S4 (0 ≦ x ≦ 0.15), Li 3+5x P 1-x S4 (0 ≦ x ≦ 0.3), etc. can be mentioned.

[0029] The glassy sulfide solid electrolyte is not particularly limited and can be appropriately selected according to the purpose. For example, Li2S-P2S5, Li2S-P2S5-LiI, Li2S-P2S5-P2O5, Li2S-P2S5-LiCl, Li2S-SiS2, Li2S-SiS2-P2S5, Li2S-SiS2-Al2S3, Li2S-SiS2-Li x MO y (M is any one of Si, P, and Ge), etc. can be mentioned. Also, Li7P3S in which a part of the glassy sulfide solid electrolyte is crystallized 11 Glass ceramics, etc. can also be used. Here, the mixing ratio of each raw material of the glassy sulfide solid electrolyte is not questioned.

[0030] In addition, the solid electrolyte for the electrode composite material layer is preferably included as particles (hereinafter referred to as solid electrolyte particles for the electrode composite material layer) in the laminate. The average particle diameter of the solid electrolyte particles for the electrode composite material layer is preferably 0.1 to 20 μm, more preferably 0.3 to 10 μm, and even more preferably 0.5 to 5.0 μm. The average particle diameter is the median diameter D50 obtained by measurement using a laser diffraction / scattering particle size distribution measuring device or the like.

[0031] When the average particle diameter of the solid electrolyte particles for the electrode composite material layer is 0.1 μm or more, handling is easy. When it is 20.0 μm or less, the dispersibility of the solid electrolyte particles for the electrode composite material layer can be increased when forming a film, it is easy to form a thin film, and furthermore, the porosity described later can be reduced.

[0032] <<Electrode active material>> As the electrode active material, a positive electrode active material or a negative electrode active material applicable to an electrochemical element can be used.

[0033] -Positive electrode active material- The positive electrode active material is not particularly limited as long as it can reversibly occlude and release alkali metal ions, but an alkali metal-containing transition metal compound can be used.

[0034] Examples of the alkali metal-containing transition metal compound include lithium-containing transition metal compounds such as composite oxides containing one or more elements selected from the group consisting of cobalt, manganese, nickel, chromium, iron, and vanadium and lithium.

[0035] Examples of the lithium-containing transition metal compound include lithium cobaltate, lithium nickelate, lithium manganate, lithium nickel cobalt manganate, and the like.

[0036] As the alkali metal-containing transition metal compound, polyanion compounds having XO4 tetrahedrons (X = P, S, As, Mo, W, Si, etc.) in the crystal structure can also be used. Among these, lithium-containing transition metal phosphate 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 input / output characteristics of the electrochemical device.

[0037] In addition, in terms of electron conductivity, it is preferable that the surface of the polyanion compound is coated and complexed with a conductive aid such as a carbon material.

[0038] -Negative electrode active material- The negative electrode active material is not particularly limited as long as it can reversibly occlude and release alkali metal ions, but a carbon material containing graphite having a graphite-type crystal structure can be used.

[0039] Examples of the carbon material include natural graphite, artificial graphite, non-graphitizable carbon (hard carbon), graphitizable carbon (soft carbon), and the like.

[0040] Examples of negative electrode active materials other than carbon materials include lithium titanate, titanium oxide, and the like.

[0041] In addition, from the viewpoint of the energy density of the electrochemical device, it is preferable to use a high-capacity material such as metallic lithium (including alloys), silicon, tin, silicon alloy, tin alloy, silicon oxide, silicon nitride, tin oxide, etc. as the negative electrode active material.

[0042] The content of the active material in the liquid composition is not particularly limited and can be appropriately selected according to the purpose, but 10% by mass or more is preferable, and 15% by mass or more is more preferable. When the content of the active material in the liquid composition is 10% by mass or more, the number of printing times required to form an electrode composite layer with a predetermined basis weight is reduced.

[0043] -Dispersant- As the dispersant, there is no particular limitation as long as it can dissolve in the dispersion medium, hardly react with the sulfide solid electrolyte, and can disperse the solid electrolyte for the electrode binder layer. It can be appropriately selected according to the purpose from conventionally known or commercially available ones. The dispersant may be used alone or in combination of two or more kinds.

[0044] In this specification, that the dispersant dissolves in the dispersion medium means that it is compatible with the dispersion medium. More specifically, when 3% by mass of the dispersant is added to the dispersion medium and dissolved, and then left standing for 10 minutes, and no sediment or supernatant is confirmed, it can be judged that it has dissolved.

[0045] Specific examples of the dispersant include, for example, polymer dispersants such as polyethylene-based, polyethylene oxide-based, polypropylene oxide-based, polycarboxylic acid-based, naphthalenesulfonic acid formalin condensation-based, polyethylene glycol-based, polycarboxylic acid partial alkyl ester-based, polyether-based, polyethyleneimine-based, polyalkylene polyamine-based; low molecular weight dispersants such as alkylsulfonic acid-based, quaternary ammonium-based higher alcohol alkylene oxide-based, polyhydric alcohol ester-based, alkylpolyamine-based; inorganic dispersants such as polyphosphate dispersants, etc.

[0046] The content of the dispersant in the liquid composition is not particularly limited and can be appropriately selected according to the purpose. However, the solid content concentration of the dispersant is preferably 10% by mass or less, more preferably 3% by mass or less, based on the solid electrolyte for the electrode binder layer to be dispersed. When the solid content concentration of the dispersant is 10% by mass or less based on the solid electrolyte for the electrode binder layer to be dispersed, the dispersant concentration does not become too high, and aggregation of the liquid composition can be suppressed.

[0047] -Binder- As the binder, there is no particular limitation as long as it can bind solid electrolytes for the electrode binder layer to each other, active materials to each other, or a solid electrolyte for the electrode binder layer to an electrode substrate (current collector) or an electrode active material to a current collector, and it can be appropriately selected according to the purpose. For example, polymer compounds, polymer particles, etc. can be mentioned. These may be used alone or in combination of two or more.

[0048] The polymer compound is not particularly limited and can be appropriately selected according to the purpose. For example, polyamide compounds, polyimide compounds, polyamide-imide, ethylene-propylene-butadiene rubber (EPBR), styrene-butadiene rubber (SBR), nitrile butadiene rubber (NBR), isoprene rubber, polyisobutene, polyethylene glycol (PEO), polymethyl methacrylic acid (PMMA), polyethylene vinyl acetate (PEVA), etc. can be mentioned.

[0049] As the polymer compound that can be dispersed in a liquid, polymer particles may be used. The maximum particle diameter of the polymer particles only needs to be smaller than the nozzle diameter of the liquid ejection head. The mode diameter of the polymer particles is preferably 0.01 to 1 μm. Examples of the material constituting the polymer particles include thermoplastic resins such as polyvinylidene fluoride, acrylic resin, styrene-butadiene rubber, polyethylene, polypropylene, polyurethane, nylon, polytetrafluoroethylene, polyphenylene sulfide, polyethylene terephthalate, and polybutylene terephthalate.

[0050] -Conductive aid- The conductive aid is not particularly limited and can be appropriately selected according to the purpose. For example, carbon materials such as conductive carbon black, carbon nanofibers, carbon nanotubes, graphene, and graphite particles can be used. Here, the conductive aid may be complexed with the active material.

[0051] The conductive carbon black can be produced, for example, by the furnace method, acetylene method, gasification method, etc.

[0052] As conductive aids other than carbon materials, for example, metal particles such as aluminum and metal fibers can be used.

[0053] The amount of the conductive aid with respect to the active material is not particularly limited and can be appropriately selected according to the purpose, but is preferably 10% by mass or less, more preferably 8% by mass or less.

[0054] - Viscosity - The viscosity of the liquid composition for forming the electrode composite layer is not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected according to the purpose, but is preferably a viscosity that can be discharged from the nozzles of the inkjet head. More specifically, the viscosity at 25 ° C is preferably 200 mPa·s or less, more preferably 100 mPa·s or less, still more preferably 50 mPa·s or less, and particularly preferably 25 mPa·s or less. The lower limit is not particularly limited, but can be appropriately set to a viscosity that can be discharged by the inkjet method.

[0055] The method for measuring the viscosity of the liquid composition is not particularly limited and can be appropriately selected according to the purpose. For example, it can be measured by attaching a rotor of No. CPA-40Z to a B-type viscometer (cone-plate viscometer). In this specification, the viscosity of the liquid composition is the viscosity at 25 ° C.

[0056] The method for producing the liquid composition for forming the electrode composite layer is not particularly limited and can be appropriately selected according to the purpose, but it is preferably produced by the method for producing the liquid composition described below.

[0057] The use of the liquid composition is not particularly limited and can be appropriately selected according to the purpose, but it can be suitably used as a material for the solid electrolyte layer of an all-solid-state secondary battery or as a part when forming a material for the electrode composite layer.

[0058] <<<Method for Producing Liquid Composition>>> The manufacturing method of the liquid composition includes a dissolution or dispersion step, and may further include other steps as necessary.

[0059] - Dissolution or dispersion step - The dissolution or dispersion step is a step of dissolving or dispersing an active material and a sulfide solid electrolyte in a dispersion medium, together with a dispersant dissolved in the dispersion medium. For example, it can be prepared by adding and mixing an active material, a sulfide solid electrolyte, a dispersant, and, if necessary, other components in a dispersion medium. The means of mixing is not particularly limited and can be appropriately selected according to the purpose. Examples include ultrasonic homogenizers. The mixing conditions are not particularly limited and can be appropriately selected according to the purpose.

[0060] The electrode composite layer has a bulk density of 1.2 to 2.1 g / cm 3 and preferably 1.2 to 2.0 g / cm 3 more preferably 1.5 to 2.0 g / cm 3 Here, the bulk density of the electrode composite layer is the bulk density of the pre-press electrode composite layer (the electrode composite layer before the formation of the solid electrolyte layer) to which the liquid composition is applied in the pre-press solid electrolyte layer formation step described later.

[0061] The method for adjusting the bulk density is not particularly limited, but it can be adjusted by uniaxial pressing or roll pressing. Among them, roll pressing is more preferable in that the variation in bulk density is less likely to occur. Also, when forming the electrode composite layer by an inkjet method, the bulk density can be adjusted by adjusting the solid content concentration and viscosity of the liquid composition. From the point that the variation in bulk density is less likely to occur than in uniaxial pressing or roll pressing, it is more preferable to adjust the bulk density by forming the electrode composite layer by an inkjet method.

[0062] The method for measuring the bulk density is not particularly limited, and it can be calculated from the volume and weight of the electrode composite layer cut out to a specified area.

[0063] <<Solid electrolyte layer>> The solid electrolyte layer contains at least a solid electrolyte for the solid electrolyte layer.

[0064] The film thickness of the solid electrolyte layer is not particularly limited, but a range of 1 to 500 μm is preferable. When the film thickness of the solid electrolyte layer is 1 μm or more, the occurrence of short circuit in the electrolyte layer is reduced, and when it is 500 μm or less, sufficient ionic conductivity can be ensured. Further, in terms of preventing short circuit in the electrolyte layer and reducing the resistance of the solid electrolyte layer, it is more preferable that the film thickness of the solid electrolyte layer is in the range of 5 to 100 μm.

[0065] <<Pre-pressurization solid electrolyte layer formation step>> The method for manufacturing the laminate according to the present embodiment includes a pre-pressurization solid electrolyte layer formation step of forming a pre-pressurization solid electrolyte layer. The pre-pressurization solid electrolyte layer formation step includes applying a liquid composition containing the components of the solid electrolyte for the solid electrolyte layer onto the pre-pressurization electrode composite layer.

[0066] In this specification, the pre-pressurization solid electrolyte layer refers to the solid electrolyte layer contained in the laminate before being pressurized in the pressurization step described later. In the pre-pressurization solid electrolyte layer formation step, a pre-pressurization laminate in which the pre-pressurization solid electrolyte layer is laminated on the pre-pressurization electrode composite layer is obtained.

[0067] The method for forming the pre-pressurization solid electrolyte layer is not particularly limited. For example, a wet coating process using a die coater, comma coater, etc. is preferable. Also, from the perspective of on-demand, it is preferable to form the pre-pressurization solid electrolyte layer by an inkjet method using a liquid composition containing the material of the pre-pressurization solid electrolyte layer with the liquid discharge device described later.

[0068] Also, when forming the pre-pressurization solid electrolyte layer with a conventional die coater, comma coater, etc., unevenness is likely to occur in the pre-pressurization solid electrolyte layer. On the other hand, when forming the pre-pressurization solid electrolyte layer by an inkjet method, unevenness is less likely to occur in the pre-pressurization solid electrolyte layer, the film thickness of the solid electrolyte layer after being pressurized in the pressurization step described later becomes uniform, and the interfacial resistance with the electrode composite layer can be reduced.

[0069] <<Liquid Composition for Forming Solid Electrolyte Layer>> The liquid composition for the solid electrolyte layer contains a dispersion medium and components of the solid electrolyte for the solid electrolyte layer, and may contain components such as a dispersant and a binder as required.

[0070] -Dispersion Medium- The dispersion medium is not particularly limited and can be appropriately selected according to the purpose. However, it is preferably a dispersion medium having a relative permittivity at 25 °C of 7.0 or less, more preferably 6.5 or less, and still more preferably 6.0 or less.

[0071] When the dispersion medium has a relative permittivity at 25 °C of 7.0 or less, it is preferable in that the dispersibility of the solid electrolyte for the solid electrolyte layer in the dispersion medium can be increased. Also, when the dispersion medium has a relative permittivity at 25 °C of 7.0 or less, when used in combination with the solid electrolyte for the solid electrolyte layer containing sulfur element described later, the reaction between the dispersion medium and the solid electrolyte for the solid electrolyte layer containing sulfur element described later is less likely to occur, and as a result, it is preferable in that the generation of toxic hydrogen sulfide can be suppressed.

[0072] The dispersion medium may be used alone or in combination of two or more. When using a mixed dispersion medium in which two or more dispersion media are combined, it is preferable that the relative permittivity of the mixed dispersion medium is 7.0 or less at 25 °C.

[0073] The method for measuring the relative permittivity of the dispersion medium is not particularly limited and can be appropriately selected according to the purpose. For example, it can be measured by performing double cylindrical tube current measurement at 10 kHz using a liquid permittivity meter (manufactured by Sanyo Trading Co., Ltd., Model 871).

[0074] Specific examples of the dispersion medium having a relative dielectric constant of 7.0 or less at 25°C include, for example, pentane, isopentane, hexane, heptane, 2,2-dimethylbutane, octane, cyclohexane, tetradecane, 1,4-dioxane, benzene, xylene, carbon tetrachloride, mesitylene, toluene, dibutyl ether, anisole, 1,2-diethoxyethane, 2-methylanisole, 3-methylanisole, 4-methylanisole, 1,2-methoxybenzene, 1,3-methoxybenzene, p-ethylaniline, 4-octanol, phenetole, 2-ethylhexyl acetate, butyl phenyl ether, isopropylbenzene, 1,2,3,4-tetrahydronaphthalene, ethyl decanoate, isobutyl acetate, diisopentyl ether, tridecane, cyclooctane, ethyl propionate, cymene, and the like.

[0075] It is preferable to use a dehydrated dispersion medium. The degree of dehydration is not particularly limited and can be appropriately selected according to the purpose. However, the water content measured by a Karl Fischer moisture concentration meter is preferably 1,000 ppm or less, more preferably 100 ppm or less, and even more preferably 10 ppm or less.

[0076] <<<Solid electrolyte for solid electrolyte layer>>> The solid electrolyte for the solid electrolyte layer is the solid electrolyte contained in the solid electrolyte layer. The solid electrolyte for the solid electrolyte layer is a solid electrolyte containing sulfur element. The solid electrolyte containing sulfur element is, for example, a sulfide solid electrolyte. The solid electrolyte for the solid electrolyte layer may be of the same type as the solid electrolyte for the above electrode composite layer.

[0077] Sulfide solid electrolytes can be broadly classified into crystalline sulfide solid electrolytes and glassy solid electrolytes. These sulfide solid electrolytes are not particularly limited as long as they have ionic conductivity without electronic conductivity. Furthermore, sulfide solid electrolytes are preferable in that they can form a good interface between solid electrolyte particles or between the solid electrolyte and the active material due to their high plasticity. The sulfide solid electrolyte may be used alone or in combination of two or more kinds.

[0078] The crystalline sulfide solid electrolyte is not particularly limited and can be appropriately selected according to the purpose. For example, Li 9.54 Si 1.74 P 1.44 S 11.7 C 10.3 , Li 9.6 P3S 12 , Li9P3S9O3, Li 9.81 Sn 0.81 P 2.19 S 12 , Li 9.42 Si 1.02 P 2.1 S 9.96 O 2.04 , Li 10 Ge(P 1-x Sb x )2S 12 (0 ≦ x ≦ 0.15), Li 10 SnP2S 12 , Li 10.35 [M1 1-x M 2x 1.35 P 1.65 S 12 (M1 and M2 are any of Si, Ge, Sn, As, and Sb), 0 ≦ x ≦ 0.15), Li 11 Si2PS 12 , Li 11 AlP2S 12 , Li 3.45 Si 0.45 P 0.55 S4, Li6PS 5X (X is any of Cl, Br, and I), Li5PS4X2 (X is any of Cl, Br, and I), Li 5.5 PS 4.5 Cl​1.5 , Li 5.35 Ca 0.1 PS 4.5 Cl 1.55 , Li 6+x M x Sb 1-x S5I (where M is any one of Si, Ge, and Sn, 0 ≦ x ≦ 1), Li7P2S8I, γ-Li3PS4, Li4MS4 (where M is any one of Ge, Sn, and As), Li 4-x Sn 1-x Sb x S4 (0 ≦ x ≦ 0.15), Li 4-x Ge 1-x P x S4 (0 ≦ x ≦ 0.15), Li 3+5x P 1-x S4 (0 ≦ x ≦ 0.3), etc. can be mentioned.

[0079] The glass-based sulfide solid electrolyte is not particularly limited and can be appropriately selected according to the purpose. For example, Li2S-P2S5, Li2S-P2S5-LiI, Li2S-P2S5-P2O5, Li2S-P2S5-LiCl, Li2S-SiS2, Li2S-SiS2-P2S5, Li2S-SiS2-Al2S3, Li2S-SiS2-Li x MO y (where M is any one of Si, P, and Ge), etc. can be mentioned. Also, Li7P3S in which a part of the glass-based sulfide solid electrolyte is crystallized 11 Glass ceramics, etc. can also be used. Here, the mixing ratio of each raw material of the glass-based sulfide solid electrolyte is not limited.

[0080] Also, the solid electrolyte for the solid electrolyte layer is preferably included as particles (hereinafter referred to as solid electrolyte particles for the solid electrolyte layer) in the laminate. Further, the average particle diameter of the solid electrolyte particles for the solid electrolyte layer is preferably in the range of 0.1 to 20 μm, more preferably 0.3 to 10 μm, and even more preferably 0.5 to 5.0 μm. The average particle diameter is the median diameter D50 obtained by measurement using a laser diffraction / scattering particle size distribution measuring device, etc.

[0081] When the average particle size of the solid electrolyte particles for the solid electrolyte layer is 0.1 μm or more, handling is easy. When it is 20.0 μm or less, the dispersibility of the solid electrolyte particles for the solid electrolyte layer can be increased when forming the solid electrolyte layer, the solid electrolyte layer is easily thinned, and further, the porosity of the solid electrolyte layer can be reduced, and the ionic conductivity in the solid electrolyte layer is improved.

[0082] In general, in the solid electrolyte layer, in order to reduce the resistance at the boundary with the electrode binder layer, there is a tendency to use solid electrolyte particles with a relatively large particle size (low grain boundary resistance), and there has been a problem that a thin solid electrolyte layer cannot be formed. On the other hand, in the laminate of this embodiment, it has been found that the resistance at the interface between the electrode binder layer and the solid electrolyte layer is suppressed, and particles with a relatively small particle size can be applied to the solid electrolyte layer. Thus, it has been found that a thin solid electrolyte layer can be formed by using the laminate of this embodiment.

[0083] -Dispersant- The dispersant is not particularly limited as long as it dissolves in the dispersion medium, hardly reacts with the sulfide solid electrolyte, and can disperse the solid electrolyte for the solid electrolyte layer, and can be appropriately selected according to the purpose from conventionally known ones or commercially available ones. The dispersant may be used alone or in combination of two or more.

[0084] In this specification, when the dispersant dissolves in the dispersion medium, it means that it is compatible with the dispersion medium. More specifically, when 3% by mass of the dispersant is added to the dispersion medium, dissolved, and then allowed to stand for 10 minutes, and no sediment or supernatant is confirmed, it can be determined that it has dissolved.

[0085] Specific examples of the dispersant include, for example, polymer dispersants such as polyethylene-based, polyethylene oxide-based, polypropylene oxide-based, polycarboxylic acid-based, naphthalenesulfonic acid formalin condensation-based, polyethylene glycol-based, polycarboxylic acid partial alkyl ester-based, polyether-based, polyethyleneimine-based, polyalkylene polyamine-based, etc.; low-molecular dispersants such as alkylsulfonic acid-based, quaternary ammonium-based higher alcohol alkylene oxide-based, polyhydric alcohol ester-based, alkyl polyamine-based, etc.; inorganic dispersants such as polyphosphate dispersants, etc.

[0086] The content of the dispersant in the liquid composition is not particularly limited and can be appropriately selected according to the purpose. However, the solid content concentration of the dispersant is preferably 10% by mass or less, more preferably 3% by mass or less, based on the solid electrolyte for the solid electrolyte layer to be dispersed. When the solid content concentration of the dispersant is 10% by mass or less based on the solid electrolyte for the solid electrolyte layer to be dispersed, the dispersant concentration does not become too high, and aggregation of the liquid composition can be suppressed.

[0087] -Binder- The binder is not particularly limited as long as it can bind solid electrolytes to each other, active materials to each other, or a solid electrolyte and a current collector or an electrode active material and a current collector, and can be appropriately selected according to the purpose. Examples include polymer compounds, polymer particles, etc. These may be used alone or in combination of two or more.

[0088] The polymer compound is not particularly limited and can be appropriately selected according to the purpose. Examples include polyamide compounds, polyimide compounds, polyamideimides, ethylene-propylene-butadiene rubber (EPBR), styrene-butadiene rubber (SBR), nitrile butadiene rubber (NBR), isoprene rubber, polyisobutene, polyethylene glycol (PEO), polymethyl methacrylate (PMMA), polyethylene vinyl acetate (PEVA), etc.

[0089] As the polymer compound capable of being dispersed in a liquid, polymer particles may be used. The maximum particle diameter of the polymer particles only needs to be smaller than the nozzle diameter of the liquid ejection head. The mode diameter of the polymer particles is preferably 0.01 to 1 μm. Examples of the material constituting the polymer particles include thermoplastic resins such as polyvinylidene fluoride, acrylic resin, styrene-butadiene rubber, polyethylene, polypropylene, polyurethane, nylon, polytetrafluoroethylene, polyphenylene sulfide, polyethylene terephthalate, and polybutylene terephthalate.

[0090] -Viscosity- The viscosity of the liquid composition for forming the solid electrolyte layer is not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected according to the purpose. However, it is preferably a viscosity that can be ejected from the nozzle of the inkjet head. More specifically, the viscosity at 25°C is preferably 200 mPa·s or less, more preferably 100 mPa·s or less, still more preferably 50 mPa·s or less, and particularly preferably 25 mPa·s or less. The lower limit value is not particularly limited, and can be appropriately set to a viscosity that can be ejected by an inkjet method.

[0091] The method for measuring the viscosity of the liquid composition is not particularly limited and can be appropriately selected according to the purpose. For example, it can be measured by attaching a rotor of No. CPA-40Z to a B-type viscometer (cone-plate viscometer). In this specification, the viscosity of the liquid composition refers to the viscosity at 25°C.

[0092] The method for producing the liquid composition for forming the solid electrolyte layer is not particularly limited and can be appropriately selected according to the purpose. However, it is preferably produced by the method for producing the liquid composition described below.

[0093] <<<Method for Producing Liquid Composition>>> The method for producing the liquid composition includes a dissolution or dispersion step, and further includes other steps as necessary.

[0094] - Dissolution or dispersion process - The dissolution or dispersion process is a process of dissolving or dispersing a sulfide solid electrolyte and a dispersant dissolved in a dispersion medium in the dispersion medium. For example, it can be prepared by introducing and mixing a sulfide solid electrolyte, a dispersant, and, if necessary, other components in the dispersion medium. The means of mixing is not particularly limited and can be appropriately selected according to the purpose. Examples include ultrasonic homogenizers. The mixing conditions are not particularly limited and can be appropriately selected according to the purpose.

[0095] <<Pressurization process>> The method for manufacturing a laminate according to the present embodiment includes a pressurization process. In the pressurization process, the pre-pressurization laminate obtained in the above pre-pressurization solid electrolyte layer formation process is pressurized.

[0096] The mode of pressurizing the pre-pressurization laminate is not particularly limited, but can be performed in the stacking direction of the laminate in a state where the pre-pressurization solid electrolyte layer is formed on the electrode composite layer by means such as uniaxial pressing, roll pressing, and isostatic pressing methods.

[0097] The pressure when pressurizing the laminate is not particularly limited, but is preferably 50 MPa or more, and more preferably about 100 to 1000 MPa. Also, the temperature during pressurization is not particularly limited as long as the material and the like do not decompose and deteriorate.

[0098] For example, by pressurizing a laminate formed by applying a pre-pressurization solid electrolyte layer on a positive electrode composite layer with adjusted bulk density, an electrode for an all-solid-state secondary battery with excellent input / output characteristics can be manufactured.

[0099] Conventionally, when forming a solid electrolyte layer on an electrode composite material layer, the volume density of the electrode composite material layer has been relatively high. As a result of intensive research by the inventors, it has been found that by applying pressure to a laminate in which a solid electrolyte layer is formed on an electrode composite material layer in a state where the volume density of the electrode composite material layer is relatively low, the resistance at the interface between the electrode composite material layer and the solid electrolyte layer is reduced. In addition, it has been found that by using such a laminate in an electrochemical element such as an all-solid-state lithium secondary battery, the input / output characteristics of the electrochemical element are improved.

[0100] This is because when the solid electrolyte layer is formed on the electrode composite material layer in a state where the volume density of the electrode composite material layer is relatively low, the interface with the solid electrolyte layer is formed while the electrode composite material layer is also crushed, and the particles on each surface are more indented, resulting in the formation of a good interface.

[0101] <<Manufacturing Method of Electrode>> The manufacturing method of the electrode includes a step of applying the liquid composition used in the manufacturing method of the laminate according to the present embodiment onto an electrode substrate, and further includes other steps as necessary.

[0102] The coating method of the liquid composition is not particularly limited, and examples include liquid ejection methods such as inkjet method, spray coating method, dispenser method, and spin coating method, casting method, microgravure coating method, gravure coating method, bar coating method, roll coating method, wire bar coating method, dip coating method, slit coating method, capillary coating method, nozzle coating method, gravure printing method, screen printing method, flexographic printing method, offset printing method, reverse printing method, and the like.

[0103] Among these, the inkjet method is particularly preferable. When the inkjet method is used, the electrode can be manufactured in a non-contact and free shape. As a result, there are effects such as less loss of the active material due to die cutting in the production process of the electrode. At this time, the liquid composition may be applied to only one side of the current collector or both sides. The thickness of the liquid composition on the current collector before drying after coating can be appropriately set according to the thickness of the electrode composite material layer obtained after drying.

[0104] As a method for drying the liquid composition on the current collector, a known method can be used without particular limitation. For example, drying methods using warm air, hot air, low-humidity air, vacuum drying, and drying by irradiation with infrared rays or electron beams can be mentioned. By drying the liquid composition on the current collector in this way, an electrode composite layer can be formed on the current collector, and an electrode including the current collector and the electrode composite layer can be obtained.

[0105] <<Container>> The container is a container in which the above-described liquid composition for forming the electrode composite layer or the liquid composition for forming the solid electrolyte layer is contained.

[0106] The shape, structure, and size of the container are not particularly limited and can be appropriately selected according to the purpose.

[0107] Hereinafter, a manufacturing apparatus and a manufacturing method for a laminate by an inkjet method will be described.

[0108] <<Manufacturing Apparatus and Manufacturing Method for Laminate>> The manufacturing apparatus for the laminate includes the above-described container of the present invention and a discharging means for discharging the liquid composition contained in the container using an inkjet head (hereinafter, may be referred to as a liquid discharge head), and may further include other configurations as necessary.

[0109] The manufacturing method for the electrode composite layer and the solid electrolyte layer includes a discharging step of discharging the liquid composition for forming the electrode composite layer or the liquid composition for forming the solid electrolyte layer in the manufacturing method for the laminate of the above-described present embodiment using an inkjet head, and may further include other steps as necessary.

[0110] <<<Discharging Means, Discharging Step>>> The discharging means is a means for discharging the liquid composition contained in the container using an inkjet head.

[0111] The discharging step is a step of discharging the liquid composition using an inkjet head.

[0112] By ejection, a liquid composition can be applied onto an object to form a liquid composition layer.

[0113] The object (hereinafter sometimes referred to as the ejection object) is not particularly limited as long as it is an object for forming an electrode mixture layer and a solid electrolyte layer, and can be appropriately selected according to the purpose. Examples thereof include an electrode substrate (current collector) and an electrode mixture layer.

[0114] <<<Other configurations, other steps>>> Other configurations in the manufacturing apparatus of the laminate are not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected according to the purpose. Examples thereof include heating means.

[0115] Other steps in the manufacturing method of the laminate are not particularly limited as long as the effects of the present invention are not impaired, and can be appropriately selected according to the purpose. Examples thereof include a heating step.

[0116] -Heating means, heating step- The heating means is a means for heating the liquid composition ejected by the ejection means.

[0117] The heating step is a step for heating the liquid composition ejected in the ejection step.

[0118] By heating, the liquid composition layer can be dried.

[0119] <<Embodiment of forming an electrode mixture layer or a solid electrolyte layer by directly applying a liquid composition to a substrate>> FIG. 1 is a schematic diagram showing an example of a manufacturing method of an electrode mixture layer or a solid electrolyte layer in the manufacturing method of a laminate according to the present embodiment.

[0120] The liquid composition 12A is stored in the tank 307 of the liquid ejection device 300 and is supplied from the tank 307 to the liquid ejection head 306 via the tube 308. Note that the number of liquid ejection devices is not limited to one, and two or more devices may be used.

[0121] When manufacturing the electrode mixture layer or the solid electrolyte layer, after installing the electrode substrate 11' on which the electrode mixture layer or the pre-pressurized solid electrolyte layer is formed on the stage 310, droplets of the liquid composition 12A are ejected from the liquid ejection head 306 onto the electrode substrate 11'. At this time, the stage 310 may move, or the liquid ejection head 306 may move. The ejected liquid composition 12A becomes the electrode mixture layer or the pre-pressurized solid electrolyte layer 12'.

[0122] In addition, the liquid ejection device 300 may be provided with a mechanism for capping the nozzles in order to prevent drying when the liquid composition 12A is not being ejected from the liquid ejection head 306.

[0123] FIG. 2 is a schematic diagram showing an example of a manufacturing apparatus for an electrode mixture layer or a solid electrolyte layer in the method for manufacturing a laminate according to the present embodiment.

[0124] The manufacturing apparatus for the electrode mixture layer or the solid electrolyte layer in FIG. 2 is an apparatus for manufacturing an electrode mixture layer using the above-described liquid composition.

[0125] The manufacturing apparatus for the electrode mixture layer or the solid electrolyte layer includes a discharge process section 8 that includes a step of applying a liquid composition onto a printing substrate 4 having a discharge target to form a liquid composition layer, and a heating process section 9 that includes a step of heating the liquid composition layer to obtain an electrode mixture layer. The manufacturing apparatus for the electrode mixture layer includes a transport section 5 that transports the printing substrate 4, and the transport section 5 transports the printing substrate 4 at a preset speed in the order of the discharge process section 8 and the heating process section 9.

[0126] The method for manufacturing the printing substrate 4 having a discharge target such as an electrode substrate or an active material layer is not particularly limited, and known methods can be appropriately selected.

[0127] The ejection engineering department 8 includes an arbitrary printing device 1a according to an inkjet printing method which is an applying means for realizing an applying step of applying a liquid composition onto a printing substrate 4, a storage container 1b for storing the liquid composition, and a supply tube 1c for supplying the liquid composition stored in the storage container 1b to the printing device 1a.

[0128] The storage container 1b stores the liquid composition 7, and the ejection engineering department 8 ejects the liquid composition 7 from the printing device 1a and applies the liquid composition 7 onto the printing substrate 4 to form a liquid composition layer in a thin film shape.

[0129] Note that the storage container 1b may be configured to be integrated with the manufacturing device of the electrode paste layer, or may be configured to be removable from the manufacturing device of the electrode paste layer. Also, it may be a container used for adding to a storage container integrated with the manufacturing device of the electrode paste layer or a storage container removable from the manufacturing device of the electrode paste layer.

[0130] The storage container 1b and the supply tube 1c can be arbitrarily selected as long as they can stably store and supply the liquid composition 7.

[0131] As shown in FIG. 2, the heating engineering department 9 includes a heating device 3a and includes a dispersion medium removal step of heating and drying the dispersion medium remaining in the liquid composition layer by the heating device 3a to remove it. Thereby, a laminate can be formed. The heating engineering department 9 may perform the dispersion medium removal step under reduced pressure.

[0132] The heating device 3a is not particularly limited and can be appropriately selected according to the purpose. For example, substrate heating, an IR heater, a hot air heater, etc. can be mentioned, and these may be combined.

[0133] Also, regarding the heating temperature and time, they can be appropriately selected according to the boiling point of the dispersion medium contained in the liquid composition 7 and the formed film thickness.

[0134] FIG. 3 is a schematic diagram showing another example of a manufacturing device (liquid ejection device) of an electrode paste layer or a solid electrolyte layer in the manufacturing method of the laminate of the present embodiment.

[0135] The liquid ejection device 300' can circulate the liquid composition through the liquid ejection head 306, the tank 307, and the tube 308 by controlling the pump 3101 and the valves 311 and 312, and can suppress the aggregation and sedimentation of solid components in the ink.

[0136] Further, the liquid ejection device 300' is provided with an external tank 313, and when the liquid composition in the tank 307 decreases, the liquid composition can be supplied from the external tank 313 to the tank 307 by controlling the pump 3101 and the valves 311, 312, and 314.

[0137] When using the manufacturing apparatus for the electrode composite layer or the solid electrolyte layer, the liquid composition can be ejected to the target position of the ejection object.

[0138] The laminate can be suitably used, for example, as a part of the configuration of an electrochemical element. The configuration other than the laminate in the electrochemical element is not particularly limited, and known ones can be appropriately selected, and examples include an electrode substrate, a separator, and the like.

[0139] An example of the method for manufacturing the electrode is shown in FIG. 4. The method for manufacturing the electrode 100 includes a step of sequentially ejecting the liquid composition 12A onto the electrode substrate 11 using the liquid ejection device 300'.

[0140] First, a long and narrow electrode substrate 11 is prepared. Then, the electrode substrate 11 is wound around a cylindrical core and set on the feeding roller 304 and the winding roller 305 so that the side for forming the electrode composite layer 12 is on the upper side in the figure. Here, the feeding roller 304 and the winding roller 305 rotate counterclockwise, and the electrode substrate 11 is conveyed in the direction from right to left in the figure. Then, droplets of the liquid composition 12A are sequentially ejected onto the conveyed electrode substrate 11 from the liquid ejection head 306 installed above the electrode substrate 11 between the feeding roller 304 and the winding roller 305 in the same manner as in FIG. 1.

[0141] Note that a plurality of liquid ejection heads 306 may be installed in a direction substantially parallel or substantially perpendicular to the conveyance direction of the electrode substrate 11. Next, the electrode substrate 11 onto which the droplets of the liquid composition 12A have been ejected is conveyed to the heating mechanism 309 by the feed roller 304 and the take-up roller 305. As a result, the electrode composite layer 12 is formed and the electrode 100 is obtained. Thereafter, the electrode 100 is cut into a desired size by punching or the like.

[0142] The heating mechanism 309 may be installed on either the upper or lower side of the electrode substrate 11, or a plurality of heating mechanisms 309 may be installed.

[0143] The heating mechanism 309 is not particularly limited as long as it does not directly contact the liquid composition 12A, and examples thereof include a resistance heating heater, an infrared heater, and a fan heater. Note that a plurality of heating mechanisms 309 may be installed. Further, a curing device using ultraviolet rays for polymerization may be installed.

[0144] Also, the liquid composition 12A ejected onto the electrode substrate 11 is preferably heated, and when heating, it may be heated by a stage or by a heating mechanism other than the stage. The heating mechanism may be installed on either the upper or lower side of the electrode substrate 11, or a plurality of heating mechanisms may be installed.

[0145] The heating temperature is not particularly limited. By heating, the liquid composition 12A dries and the electrode composite layer is formed.

[0146] Also, as shown in FIG. 5, the liquid ejection device 300' may be composed of a liquid ejection device 300A and a liquid ejection device 300B. The liquid ejection device 300A includes a head 306A and a tank 307A, and the liquid ejection device 300B includes a head 306B and a tank 307B.

[0147] Specifically, as shown in FIG. 5, the tank 307 may supply ink from external tanks 313A and 313B connected to tanks 307A and 307B via valves 314A and 314B. Further, the liquid ejection head 306 may have a plurality of heads 306A and 306B via tubes 308A and 308B provided with valves 312A and 312B from tanks 307A and 307B.

[0148] Furthermore, the liquid ejection device 300A can circulate the liquid composition through the liquid ejection heads 306A, the tank 307A, and the tube 308A by controlling the pump 3101A and the valves 311A and 312A. Also, the liquid ejection device 300B can circulate the liquid composition through the liquid ejection heads 306B, the tank 307B, and the tube 308B by controlling the pump 3101B and the valves 311B and 312B.

[0149] Furthermore, the liquid ejection device 300A can also supply the liquid composition from the external tank 313A to the tank 307A by controlling the pump 3101A and the valves 311A, 312A, and 314A. Also, the liquid ejection device 300B can also supply the liquid composition from the external tank 313B to the tank 307B by controlling the pump 3101B and the valves 311B, 312B, and 314B.

[0150] <<Embodiment of forming a laminate by indirectly applying a liquid composition to a substrate>> FIGS. 6 to 7 are configuration diagrams showing an example of a printing unit that employs an inkjet method and a transfer method as applying means as a manufacturing apparatus for the laminate of the present embodiment. FIG. 6 is a configuration diagram showing a printing unit using a drum-shaped intermediate transfer body, and FIG. 7 is a configuration diagram showing a printing unit using an endless belt-shaped intermediate transfer body. The printing unit 400 shown in FIG. 6 is an inkjet printer that forms a laminate on a substrate by transferring a liquid composition layer to the substrate via an intermediate transfer body 4001.

[0151] The printing unit 400 includes an inkjet unit 420, a transfer drum 4000, a pretreatment unit 4002, an absorption unit 4003, a heating unit 4004, and a cleaning unit 4005.

[0152] The inkjet unit 420 includes a head module 422 that holds a plurality of heads 401. The head 401 discharges a liquid composition onto an intermediate transfer member 4001 supported by the transfer drum 4000 to form a liquid composition layer on the intermediate transfer member 4001. Each head 401 is a line head, and nozzles are arranged in a range that covers the width of the recording area of the substrate with the maximum size that can be used. The head 401 has a nozzle surface formed with nozzles on its lower surface, and the nozzle surface faces the surface of the intermediate transfer member 4001 with a minute gap therebetween. In the case of this embodiment, since the intermediate transfer member 4001 is configured to circulate and move on a circular orbit, the plurality of heads 401 are arranged radially.

[0153] The transfer drum 4000 faces the impression cylinder 621 to form a transfer nip portion. The pretreatment unit 4002 applies a reaction liquid for increasing the viscosity of the liquid composition, for example, onto the intermediate transfer member 4001 before the discharge of the liquid composition by the head 401. The absorption unit 4003 absorbs the liquid component from the liquid composition layer on the intermediate transfer member 4001 before transfer. The heating unit 4004 heats the liquid composition layer on the intermediate transfer member 4001 before transfer. By heating the liquid composition layer, it is dried to form a laminate (electrode composite layer or solid electrolyte layer). Also, the dispersion medium is removed, and the transferability to the substrate is improved. The cleaning unit 4005 cleans the intermediate transfer member 4001 after transfer to remove foreign matters such as ink and dust remaining on the intermediate transfer member 4001.

[0154] The outer peripheral surface of the impression cylinder 621 is in pressure contact with the intermediate transfer member 4001, and when the substrate passes through the transfer nip portion between the impression cylinder 621 and the intermediate transfer member 4001, the liquid composition layer on the intermediate transfer member 4001 is transferred to the substrate. Note that the impression cylinder 621 may be configured to include at least one grip mechanism that holds the leading end portion of the substrate on its outer peripheral surface.

[0155] The printing unit 400' shown in FIG. 7 is an inkjet printer that forms a laminate on a substrate by transferring a liquid composition layer to the substrate via an intermediate transfer belt 4006.

[0156] The printing unit 400' discharges droplets of a liquid composition from a plurality of heads 401 provided in an inkjet unit 420 to form a liquid composition layer on the outer peripheral surface of the intermediate transfer belt 4006. The liquid composition layer formed on the intermediate transfer belt 4006 is heated by a heating unit 4007 and dried to form a laminate, which is film-formed on the intermediate transfer belt 4006.

[0157] At a transfer nip portion where the intermediate transfer belt 4006 faces a transfer roller 622, the film-formed laminate on the intermediate transfer belt 4006 is transferred to the substrate. The surface of the intermediate transfer belt 4006 after transfer is cleaned by a cleaning roller 4008.

[0158] The intermediate transfer belt 4006 is spanned over a driving roller 4009a, a counter roller 4009b, a plurality (four in this example) of shape-maintaining rollers 4009c, 4009d, 4009e, 4009f, and a plurality (four in this example) of support rollers 4009g, and moves in the direction of the arrow in the figure. The support roller 4009g provided opposite to the head 401 maintains the tensile state of the intermediate transfer belt 4006 when ink droplets are discharged from the head 401.

[0159] <<Positive electrode>> FIG. 8 shows an example of a positive electrode used in the laminate of this embodiment.

[0160] The positive electrode 10 has a positive electrode composite layer 12 formed on one side of a positive electrode substrate 11. Further, a solid electrolyte layer 30 is formed on the upper surface of the positive electrode composite layer 12.

[0161] The shape of the positive electrode 10 is not particularly limited, and examples include a flat plate shape. Examples of the material constituting the positive electrode substrate 11 include stainless steel, nickel, aluminum, copper, and the like.

[0162] Note that the positive electrode composite layer 12 may be formed on both sides of the positive electrode substrate 11.

[0163] In the positive electrode 10, the laminate 101 is constituted by the positive electrode 10 (excluding the positive electrode substrate 11) and the solid electrolyte layer 30. The laminate 101 can be manufactured using the manufacturing apparatus for the laminate described above.

[0164] <<Adhesive layer>> FIG. 9 shows a modified example of the positive electrode used in the laminate of the present embodiment. In FIG. 9, portions common to FIG. 8 are denoted by the same reference numerals as in FIG. 8, and the description thereof is omitted. In FIG. 9, an adhesive layer 13 is formed between the positive electrode substrate 11 and the positive electrode composite layer 12. By providing such an adhesive layer 13, the adhesion between the positive electrode substrate 11 and the positive electrode composite layer 12 can be enhanced.

[0165] The components of the adhesive layer 13 are not particularly limited, but preferably include a metal that alloyizes with a metal element contained in a positive electrode active material such as lithium.

[0166] The adhesive layer 13 can be manufactured using the manufacturing apparatus for the laminate described above from a liquid composition containing the components of the adhesive layer.

[0167] <<Negative electrode>> FIG. 10 shows an example of the negative electrode used in the laminate of the present embodiment.

[0168] In the negative electrode 20, a negative electrode composite layer 22 is formed on one side of a negative electrode substrate 21. Further, a solid electrolyte layer 30 is formed on the upper surface of the negative electrode composite layer 22.

[0169] The shape of the negative electrode 20 is not particularly limited, and examples thereof include a flat plate shape. Examples of the material constituting the negative electrode substrate 21 include stainless steel, aluminum, titanium, tantalum, and the like.

[0170] Note that the negative electrode composite layer 22 may be formed on both sides of the negative electrode substrate 21.

[0171] In the negative electrode 20, the laminate 102 is formed by the negative electrode 20 (excluding the negative electrode substrate 21) and the solid electrolyte layer 30. The laminate 102 can be manufactured using the manufacturing apparatus for the laminate described above.

[0172] Note that, in the negative electrode 20, similar to the positive electrode 10, an adhesive layer (not shown) may be formed between the negative electrode substrate 21 and the negative electrode composite material layer 22.

[0173] <<Electrode cell>> FIG. 11 shows an example of an electrode cell in which the laminate of the present embodiment is used. In FIG. 11, parts common to FIGS. 8 and 10 are denoted by the same reference numerals as in FIGS. 8 and 10, and the description thereof is omitted.

[0174] In the electrode cell 103, the solid electrolyte layer 30 is formed on the upper surface of the positive electrode 10, and the negative electrode 20 is formed on the upper surface of the solid electrolyte layer 30. Specifically, the positive electrode composite material layer 12 is laminated on the lower surface of the solid electrolyte layer 30, and the negative electrode composite material layer 22 is laminated on the upper surface of the solid electrolyte layer 30. In the electrode cell 103, the laminate is formed by the positive electrode composite material layer 12, the negative electrode composite material layer 22, and the solid electrolyte layer 30.

[0175] That is, in the electrode cell 103, electrode composite material layers are formed on both surfaces of the solid electrolyte layer 30. The electrode composite material layer formed on one surface of the solid electrolyte layer 30 is the positive electrode composite material layer 12 containing a positive electrode active material. The electrode composite material layer formed on the other surface of the solid electrolyte layer 30 is the negative electrode composite material layer 22 containing a negative electrode active material. The laminate is formed by the positive electrode composite material layer 12, the negative electrode composite material layer 22, and the solid electrolyte layer 30.

[0176] Note that the electrode cell 103 may have a configuration in which the solid electrolyte layer 30 is formed on the upper surface of the positive electrode 10, and a metal lithium layer as the negative electrode 20 is formed on the upper surface of the solid electrolyte layer 30. Specifically, it may have a configuration in which the positive electrode composite material layer 12 is laminated on the lower surface of the solid electrolyte layer 30, and the metal lithium layer is laminated on the upper surface of the solid electrolyte layer 30. That is, the electrode cell 103 may have a configuration in which no negative electrode composite material layer is provided.

[0177] The laminate can be manufactured using the above-described laminate manufacturing apparatus.

[0178] In the electrode cell 103, similar to the positive electrode 10 and the negative electrode 20, an adhesive layer (not shown) may be formed between the positive electrode substrate 11 and the positive electrode composite layer 12 and / or between the negative electrode substrate 21 and the negative electrode composite layer 22.

[0179] The electrode cell 103 is preferably stored in a sealed container or the like so as not to react with moisture in the air or the like.

[0180] Also, FIG. 12 shows another example of the electrode cell in which the laminate of the present embodiment is used. In FIG. 12, for the parts common to FIGS. 8, 10, and 11, the same reference numerals as those in FIGS. 8, 10, and 11 are given and the description is omitted.

[0181] In the electrode cell 104, a solid electrolyte layer 30 is formed on the upper surface of the positive electrode 10, and a negative electrode substrate 21 is formed on the upper surface of the solid electrolyte layer 30. Specifically, a positive electrode composite layer 12 is laminated on the lower surface of the solid electrolyte layer 30, and a negative electrode substrate 21 is provided on the upper surface of the solid electrolyte layer 30. In the electrode cell 104, the negative electrode is constituted by the negative electrode substrate 21.

[0182] That is, the electrode cell 104 has a positive electrode substrate 11, a positive electrode composite layer 12 formed on the positive electrode substrate 11, a solid electrolyte layer 30 formed on the positive electrode composite layer 12, and a negative electrode substrate 21 formed on the solid electrolyte layer 30.

[0183] In the electrode cell 104, the laminate is constituted by the positive electrode composite layer 12 and the solid electrolyte layer 30. The laminate can be manufactured using the above-described laminate manufacturing apparatus.

[0184] In the electrode cell 104, similar to the positive electrode 10, an adhesive layer (not shown) may be formed between the positive electrode substrate 11 and the positive electrode composite layer 12.

[0185] The electrode cell 104 is preferably stored in a sealed container or the like, similar to the electrode cell 103.

[0186] <Manufacturing Method of Electrochemical Element> The manufacturing method of the electrochemical element according to this embodiment includes a step of forming a laminate by the manufacturing method of the laminate according to this embodiment. That is, the manufacturing method of the electrochemical element according to this embodiment includes the above-mentioned solid electrolyte layer forming step before pressurization and the pressurization step, and an electrochemical element is manufactured from the laminate obtained by carrying out these steps. Further, the manufacturing method of the electrochemical element according to this embodiment further includes other configurations as necessary.

[0187] The electrochemical element has a laminate in which a solid electrolyte layer is formed on the above-described electrode mixture layer, and may further have other configurations as necessary.

[0188] The solid electrolyte layer is the same as the solid electrolyte layer formed by the above-described liquid composition.

[0189] Hereinafter, as an example of the electrochemical element, the case of a secondary battery will be described, but the present invention is not limited to the following example.

[0190] <<Electrode>> As the electrode that can be used in the secondary battery, without particular limitation, a known electrode used in the manufacture of the secondary battery can be used. Specifically, an electrode formed by forming an electrode mixture layer on a current collector using a known manufacturing method can be used.

[0191] <<Electrolyte>> As the electrolyte other than the above-described solid electrolyte layer of this embodiment that can be used in the secondary battery, without particular limitation, a known solid electrolyte or electrolyte solution used in the manufacture of the secondary battery can be used.

[0192] <<Exterior>> The exterior is not particularly limited as long as it can seal the electrode and the solid electrolyte.

[0193] <<Manufacturing Apparatus of Electrochemical Element>>

[0194] The manufacturing apparatus for an electrochemical element includes a laminate manufacturing unit that manufactures a laminate by the above-described laminate manufacturing apparatus, and further includes other configurations as necessary.

[0195] The electrochemical element of the present embodiment can be manufactured, for example, by superposing a positive electrode and a negative electrode via a solid electrolyte, winding, folding, etc. this as necessary according to the battery shape, placing it in a battery container, and injecting and sealing an electrolytic solution into the battery container.

[0196] Fig. 13 shows an example of an electrode element used for the electrochemical element according to the present embodiment.

[0197] In the electrode element 40, a positive electrode 15 and a negative electrode 25 are laminated via a solid electrolyte 30B. Here, the positive electrode 15 is laminated on both sides of the negative electrode 25. Further, a lead wire 41 is connected to the positive electrode substrate 11, and a lead wire 42 is connected to the negative electrode substrate 21.

[0198] The positive electrode 15 has positive electrode composite material layers 12B formed on both surfaces of a positive electrode substrate 11B.

[0199] The negative electrode 25 has negative electrode composite material layers 22 formed on both surfaces of a negative electrode substrate 21.

[0200] Note that the number of laminations of the positive electrode 15 and the negative electrode 25 in the electrode element 40 is not particularly limited. Also, the number of positive electrodes 15 and the number of negative electrodes 25 in the electrode element 40 may be the same or different.

[0201] <<Electrochemical Element>> Fig. 14 shows an example of the electrochemical element of the present embodiment.

[0202] When the electrochemical element 1 is a solid electrochemical element, a solid electrolyte layer 51 is formed on the electrode element 40 and is sealed by an exterior 52. In the electrochemical element 1, the lead wires 41 and 42 are drawn out to the outside of the exterior 52.

[0203] The shape of the electrochemical element 1 is not particularly limited, and examples thereof include a laminate type, a cylinder type in which a sheet electrode and a solid electrolyte layer are spiral, a cylinder type of an inside-out structure in which a pellet electrode and a solid electrolyte layer are combined, and a coin type in which a pellet electrode and a solid electrolyte layer are laminated.

[0204] [[Applications of Electrochemical Elements]] The electrochemical element can be suitably used as a secondary battery. Further, the secondary battery using the electrochemical element is preferably a lithium ion secondary battery.

[0205] The applications of the electrochemical element are not particularly limited and can be appropriately selected according to the purpose. For example, mobile bodies such as vehicles; electrical devices such as smartphones, notebook computers, pen input computers, mobile computers, e-book players, mobile phones, mobile faxes, mobile copiers, mobile printers, headphone stereos, video movies, liquid crystal TVs, handy cleaners, portable CDs, mini discs, transceivers, electronic notebooks, calculators, memory cards, portable tape recorders, radios, backup power supplies, motors, lighting fixtures, toys, game devices, watches, strobes, cameras, etc. Among these, vehicles and electrical devices are particularly preferred.

[0206] Examples of the mobile body include ordinary automobiles, large special automobiles, small special automobiles, trucks, large motorcycles, and ordinary motorcycles.

[0207] [[Mobile Body]] FIG. 15 shows an example of a mobile body equipped with a all-solid-state battery which is an example of the electrochemical element of the present embodiment. The mobile body 550 is, for example, an electric vehicle. The mobile body 550 includes a motor 551, an electrochemical element 552, and wheels 553 as an example of a moving means.

[0208] The electrochemical element 552 is the electrochemical element of the present embodiment described above. The electrochemical element 552 drives the motor 551 by supplying power to the motor 551. The driven motor 551 can drive the wheel 553, and as a result, the moving body 550 can move.

[0209] According to the above configuration, since it is driven by the power from the electrochemical element with excellent input / output characteristics, the moving body can be moved with high efficiency.

[0210] The moving body 550 is not limited to an electric vehicle, and may be a hybrid electric vehicle (HEV) such as a plug-in hybrid electric vehicle (PHEV), or a locomotive or motorcycle (bike) that can travel by using a diesel engine and an electrochemical element in combination.

[0211] Also, the moving body may be a transport robot used in a factory or the like that can travel using only the electrochemical element or in combination with an engine and the electrochemical element. Further, the moving body may be one in which only a part moves without the entire object moving, for example, an assembly robot arranged on a manufacturing line in a factory, in which only the electrochemical element or an arm or the like can operate in combination with an engine and the electrochemical element.

Example

[0212] Hereinafter, the present invention will be described in more detail using examples. Note that the present invention is not limited to the examples. The following operations were carried out in an argon glove box maintained at a dew point environment of -70°C or lower in order to suppress the reaction between the inorganic solid electrolyte and moisture in the air, unless otherwise specified.

[0213] The average particle diameter of the solid electrolyte particles, the interfacial resistance between the positive electrode composite layer / solid electrolyte layer, and the input / output characteristics of the all-solid-state lithium secondary battery in the preparation examples, examples, and comparative examples described below were measured as follows.

[0214] -Method for Measuring Particle Size and Particle Size Distribution- First, a liquid composition containing the components of the electrode binder layer and the components of the solid electrolyte layer was diluted with the same dispersion medium so that the solid content concentration became 0.1 to 10 ppm to obtain a diluted solution. This diluted solution was placed in a quartz glass container and sealed with a packing. Next, the quartz glass container sealed with the packing was taken out of the glove box, and the average particle size (median diameter D50) was calculated using a laser diffraction / scattering particle size distribution measuring device (manufactured by Horiba, Ltd., LA-960). Here, the dilution concentration was adjusted with the same dispersion medium used in the liquid composition so that the transmitted light intensity of the laser diffraction / scattering particle size distribution measuring device fell within an appropriate range.

[0215] -Synthesis of Sulfide Solid Electrolyte (Example) and Oxide Solid Electrolyte (Comparative Example)- Ardipite (Li6PS5Cl) of the sulfide solid electrolyte was synthesized according to Non-Patent Document 1 (H.-J. Deiseroth, S.-T. Kong, H. Eckert, J. Vannahme, C. Reiner, T. Zaissand, M. Schlosser, Angew. Chem., Int. Ed. 47, 755 (2008)), LGPS (Li 10 GePS 12 ) of the sulfide solid electrolyte was synthesized according to Non-Patent Document 2 (N. Kamaya, K. Homma, Y. Yamakawa, M. Hirayama, R. Kanno, M. Yonemura, T. Kamiyama, Y. Kato, S. Hama, K. Kawamoto & A. Mitsui, Nature Materials 10, 682 (2011)), and LLZ (Li7La3Zr2O 12 ) of the oxide solid electrolyte was synthesized according to Non-Patent Document 3 (R. Murugan, V. Thangadurai, and W. Weppner, Angew. Chem. Int. Ed. 46, 7778 (2007)). A solid electrolyte with a specified particle size was prepared using a fine pulverizer (manufactured by Aisin Nanotechnology Co., Ltd., Nano Jet Mill NJ-50).

[0216] -Fabrication of Electrode Binder Layer- The cathode active material lithium nickel cobalt manganese oxide (manufactured by Easpring Technology New Material, LiNi 0.8 Co 0.1 Mn 0.1 O2) that has been pre-coated with lithium niobate (LiNbO3), argyrodite sulfide solid electrolyte (synthetic product, average particle size: 0.1 μm), polymethyl methacrylate (PMMA, synthetic product), conductive carbon black (manufactured by Lion Specialty Chemicals), and a dispersant (manufactured by Lubrizol, S21000, addition amount: 1% by mass) were dispersed in octane (manufactured by Tokyo Chemical Industry) so that the above solid content components became 30% by mass, and were processed at 30,000 rpm for 1 hour using a high-speed rotary homogenizer (manufactured by Kinematica, MT3100S2) to prepare a liquid composition. Then, using a droplet observation device (manufactured by Ricoh, EV1000), the above liquid composition was ejected from an inkjet head (nozzle diameter: 40 μm) onto an aluminum foil that is the cathode substrate, and heated on a hot plate maintained at 120°C for 60 minutes to form a cathode composite layer (basis weight: 10 mg / cm 2 , active material ratio: 75%) on the cathode substrate. Then, the cathode composite layer was roll-pressed to adjust to a predetermined bulk density.

[0217] - Fabrication of the pre-pressurized solid electrolyte layer - The above synthetic solid electrolyte and dispersant (manufactured by Lubrizol, S21000, addition amount: 1% by mass) were dispersed in octane (manufactured by Tokyo Chemical Industry) so that the above solid content components became 10 to 50% by mass, and were processed at 30,000 rpm for 1 hour using a high-speed rotary homogenizer (manufactured by Kinematica, MT3100S2) to prepare a liquid composition containing the components of the solid electrolyte layer. Then, the liquid composition with a solid content of 30% by mass was ejected from an inkjet head (nozzle diameter: 40 μm) of a droplet observation device (manufactured by Ricoh, EV1000) onto the cathode composite layer with adjusted bulk density, and heated on a hot plate maintained at 120°C for 60 minutes to obtain a laminate in which a pre-pressurized solid electrolyte layer was formed on the cathode composite layer.

[0218] Also, for the liquid compositions with solid content of 30% by mass and 50% by mass, a film was formed on the positive electrode composite layer with adjusted bulk density using a bar coater, and it was heated on a hot plate maintained at 120°C for 60 minutes to obtain a laminate in which a solid electrolyte layer before pressing was formed on the positive electrode composite layer.

[0219] Furthermore, the solvent of the liquid composition discharged from the above inkjet head was changed from octane (relative permittivity: 2.1) to anisole (manufactured by Tokyo Chemical Industry Co., Ltd., relative permittivity: 4.3), ethyl decanoate (manufactured by Tokyo Chemical Industry Co., Ltd., relative permittivity: 3.75), p-cymene (manufactured by Tokyo Chemical Industry Co., Ltd., relative permittivity: 2.2), p-chloroanisole (manufactured by Tokyo Chemical Industry Co., Ltd., relative permittivity: 7.84), and similarly, a laminate in which a solid electrolyte layer before pressing was formed on the positive electrode composite layer was obtained.

[0220] - Formation of the interface between the positive electrode composite layer and the solid electrolyte layer - The positive electrode composite layer / solid electrolyte layer before pressing was punched out to Φ10 and pressed at 300 MPa using a Φ10 pelletizer and a uniaxial press to construct the interface between the positive electrode composite layer and the solid electrolyte layer. At this time, the thickness of the positive electrode layer (positive electrode substrate and positive electrode composite layer) was about 40 μm, and the thickness of the negative electrode layer was about 20 μm.

[0221] - Fabrication of the all-solid-state lithium secondary battery evaluation cell - The pressed positive electrode composite layer / solid electrolyte layer, In foil (manufactured by Nilaco Co., Ltd., Φ10), Li foil (manufactured by Honjo Metal Co., Ltd., Φ5), and Cu mesh (manufactured by Nilaco Co., Ltd., Φ10) were placed in a Φ10 pelletizer and pressed at 100 MPa, and then placed in a prototype sealed all-solid-state lithium secondary battery cell (manufactured by Hosen Co., Ltd.) and used as an all-solid-state lithium secondary battery evaluation cell.

[0222] - Input / output characteristics - The fabricated all-solid-state lithium secondary battery evaluation cell was subjected to charge-discharge tests using a charge-discharge test device (manufactured by Toyo System Co., Ltd., TOSCAT-3100) within a voltage range of 3.7 V to 2.4 V (inside a 25°C constant temperature bath). As input-output characteristics, "1.0C discharge capacity / 0.1C discharge capacity" was calculated as the capacity retention rate and regarded as the "output characteristics". Similarly, the test was carried out in the charged state (input), but since the trend was the same as that in the discharged state (output), the data of the "input characteristics" are omitted. Note that the input-output characteristics were evaluated as good for C and above and poor for D.

[0223] 〔Evaluation Criteria〕 AA: The 1.0C discharge capacity retention rate (output characteristics) was 90% or more. A: The 1.0C discharge capacity retention rate (output characteristics) was 85% or more and less than 90%. C: The 1.0C discharge capacity retention rate (output characteristics) was 70% or more and less than 85%. D: The 1.0C discharge capacity retention rate (output characteristics) was less than 70%.

[0224] - Interface Resistance between the Positive Electrode Composite Layer and the Solid Electrolyte Layer - As an evaluation of the interface resistance between the positive electrode composite layer and the solid electrolyte layer, AC impedance measurement (inside a 25°C constant temperature bath) was carried out at a frequency of 1000 kHz to 0.1 Hz with the SOC (State Of Charge) of the all-solid-state lithium secondary battery evaluation cell at 50%. The arc that appeared was fitted, and its resistance was regarded as the "interface resistance between the positive electrode composite layer and the solid electrolyte layer". Note that the interface resistance was evaluated as good for C and above and poor for D.

[0225] 〔Evaluation Criteria〕 AA: The interface resistance was 10 Ω·cm 2 or less. A: The interface resistance was 10 Ω·cm 2 exceeding 40 Ω·cm 2 or less. C: The interface resistance was 41 Ω·cm 2 exceeding 80 Ω·cm 2 or less. D: The interface resistance was 81 Ω·cm 2 exceeding 100 Ω·cm 2 or less.

[0226] <Example 1> The positive electrode composite layer was formed by an inkjet method (hereinafter referred to as the IJ method or IJ), and the volume density of the positive electrode composite layer before interface formation (before solid electrolyte layer formation) was adjusted to 1.2 g / cm 3 A laminate was produced in which a rhodite having an average particle diameter of 1.0 μm was used as the material of the solid electrolyte layer, and the solid electrolyte layer before pressurization was formed by the IJ method.

[0227] <Example 2> The volume density of the positive electrode composite layer was adjusted to 1.5 g / cm 3 A laminate was produced in the same manner as in Example 1 except for this.

[0228] <Example 3> The volume density of the positive electrode composite layer was adjusted to 1.7 g / cm 3 A laminate was produced in the same manner as in Example 1 except for this.

[0229] <Example 4> The volume density of the positive electrode composite layer was adjusted to 2.0 g / cm 3 A laminate was produced in the same manner as in Example 1 except for this.

[0230] <Example 5> The volume density of the positive electrode composite layer was adjusted to 2.1 g / cm 3 A laminate was produced in the same manner as in Example 1 except for this.

[0231] <Example 6> A laminate was produced in the same manner as in Example 3 except that a rhodite having an average particle diameter of 0.5 μm was used as the material of the solid electrolyte layer.

[0232] <Example 7> A laminate was produced in the same manner as in Example 3 except that a rhodite having an average particle diameter of 5.0 μm was used as the material of the solid electrolyte layer.

[0233] <Example 8> The material of the solid electrolyte layer was a sulfide solid electrolyte (LGPS) with an average particle size of 1.0 μm, and the laminate was produced in the same manner as in Example 3 except for this.

[0234] <Example 9> The positive electrode composite layer was formed by coating with a bar coater using the same liquid composition used in the IJ method so that the basis weight was 10 mg / cm 2 after drying. The solid electrolyte layer before pressing was formed by coating with a bar coater using the same liquid composition used in the IJ method so that the thickness became 20 μm after interface formation, and the laminate was produced in the same manner as in Example 3 except for this.

[0235] <Example 10> The material of the solid electrolyte layer was argyrodite with an average particle size of 0.1 μm, and the laminate was produced in the same manner as in Example 3 except for this.

[0236] <Example 11> The material of the solid electrolyte layer was argyrodite with an average particle size of 10.0 μm, and the laminate was produced in the same manner as in Example 3 except for this. The conditions and results of Example 11 are shown in Table 1.

[0237] <Example 12> A liquid composition with a solid content ratio of 10 wt% was formed by coating with a bar coater so that the thickness of the solid electrolyte layer became 20 μm after interface formation, and the laminate was produced in the same manner as in Example 9 except for this.

[0238] <Example 13> A liquid composition with a solid content ratio of 50 wt% was formed by coating with a bar coater so that the thickness of the solid electrolyte layer became 20 μm after interface formation, and the laminate was produced in the same manner as in Example 9 except for this. The conditions and results of Example 13 are shown in Table 1.

[0239] <Example 14> The solvent of the liquid composition containing the components of the solid electrolyte layer was anisole, and the laminate was produced in the same manner as in Example 3 except for this.

[0240] <Example 15> The solvent of the liquid composition containing the components of the solid electrolyte layer was ethyl decanoate, and a laminate was produced in the same manner as in Example 3 except for this.

[0241] <Example 16> The solvent of the liquid composition containing the components of the solid electrolyte layer was p-cymene, and a laminate was produced in the same manner as in Example 3 except for this.

[0242] <Example 17> The solvent of the liquid composition containing the components of the solid electrolyte layer was p-chloroanisole (relative permittivity: 7.84), and a laminate was produced in the same manner as in Example 3 except for this.

[0243] <Comparative Example 1> The volume density of the positive electrode composite material layer was adjusted to 1.1 g / cm 3 and a laminate was produced in the same manner as in Example 1 except for this.

[0244] <Comparative Example 2> The volume density of the positive electrode composite material layer was adjusted to 2.2 g / cm 3 and a laminate was produced in the same manner as in Example 1 except for this.

[0245] <Comparative Example 3> The volume density of the positive electrode composite material layer was adjusted to 2.5 g / cm 3 and a laminate was produced in the same manner as in Example 1 except for this.

[0246] <Comparative Example 4> The volume density of the positive electrode composite material layer was adjusted to 3.0 g / cm 3 and a laminate was produced in the same manner as in Example 1 except for this. The conditions and results of Comparative Example 4 are shown in Table 1.

[0247] <Comparative Example 5> The volume density of the positive electrode composite material layer was adjusted to 2.5 g / cm 3 and a laminate was produced in the same manner as in Example 9 except for this.

[0248] <Comparative Example 6> A solid electrolyte layer of a pressed powder was previously formed from the same liquid composition used in the IJ method, and this was laminated on the positive electrode composite material layer. Otherwise, a laminate was produced in the same manner as in Example 3.

[0249] <Comparative Example 7> The volume density of the positive electrode composite material layer was adjusted to 2.5 g / cm 3 and a laminate was produced in the same manner as in Comparative Example 6, except for this.

[0250] <Comparative Example 8> An oxide solid electrolyte (LLZ) with an average particle diameter of 1.0 μm was used as the material for the solid electrolyte layer, and a laminate was produced in the same manner as in Example 3, except for this.

[0251] Using the laminates of Examples 1 to 14 and Comparative Examples 1 to 8, all-solid-state lithium secondary battery evaluation cells were prototyped and electrical property evaluations were carried out. The results are shown in Table 1.

[0252]

Table 1

[0253] From Table 1, as in Examples 1 to 16, the volume density of the positive electrode composite material layer before pressing was 1.2 to 2.1 g / cm 3 and in all-solid-state lithium secondary battery evaluation cells using a laminate in which the solid electrolyte for the solid electrolyte contains a sulfur element and the solid electrolyte layer before pressing is formed from a liquid composition containing the components of the solid electrolyte and the laminate is pressed, both the interfacial resistance and the output characteristics were good.

[0254] On the other hand, as in Comparative Examples 1 to 6, the volume density of the positive electrode composite material layer before pressing was 1.2 to 2.1 g / cm 3 and in all-solid-state lithium secondary battery evaluation cells that do not satisfy at least one of the conditions of being, the solid electrolyte for the solid electrolyte containing a sulfur element, forming the solid electrolyte layer before pressing from a liquid composition containing the components of the solid electrolyte, and pressing the laminate, both the interfacial resistance and the output characteristics were poor.

[0255] Aspects according to this embodiment are, for example, as follows.

[0256] <1> An electrode composite layer containing a solid electrolyte for an electrode composite layer and an electrode active material, A method for manufacturing a laminate having a solid electrolyte layer containing a solid electrolyte for the solid electrolyte layer formed on the electrode composite layer, comprising: A pre-pressurization solid electrolyte layer forming step of forming a pre-pressurization solid electrolyte layer, including applying a liquid composition containing components of the solid electrolyte layer onto the pre-pressurization electrode composite layer; A pressurization step of pressurizing the pre-pressurized laminate obtained in the pre-pressurization solid electrolyte layer forming step, The solid electrolyte for the solid electrolyte layer contains a sulfur element, The volume density of the pre-pressurization electrode composite layer onto which the liquid composition is applied in the pre-pressurization solid electrolyte layer forming step is 1.2 to 2.1 g / cm 3 is A method for manufacturing a laminate.

[0257] <2> The solid electrolyte for the solid electrolyte layer is contained as particles in the laminate, The average particle diameter of the particles is 0.1 to 20 μm, The method for manufacturing a laminate according to <1>.

[0258] <3> In the pre-pressurization solid electrolyte layer forming step, the liquid composition is ejected by an inkjet head to form the solid electrolyte layer, The method for manufacturing a laminate according to <1> or <2>.

[0259] <4> The liquid composition contains a dispersion medium, The relative permittivity of the dispersion medium at 25 °C is 7.0 or less, The method for manufacturing a laminate according to any one of <1> to <3>. The liquid composition described.

[0260] <5> Before the pre-pressurization solid electrolyte layer forming step, it has an electrode composite layer forming step of forming the electrode composite layer from a liquid composition containing components of the electrode composite layer, The method for manufacturing a laminate according to any one of <1> to <4> above.

[0261] <6> In the electrode composite layer forming step, the liquid composition is ejected by an inkjet head to form the electrode composite layer. The method for manufacturing a laminate according to <5> above.

[0262] <7> The liquid composition containing the components of the electrode composite layer contains a dispersion medium. The relative permittivity of the dispersion medium at 25 °C is 7.0 or less. The method for manufacturing a laminate according to <5> or <6> above.

[0263] <8> The electrode composite layer is formed on an electrolytic substrate. An adhesive layer is formed between the electrode substrate and the electrode composite layer. The method for manufacturing a laminate according to any one of <1> to <7> above.

[0264] <9> The electrode composite layer is a positive electrode composite layer containing a positive electrode active material. The method for manufacturing a laminate according to any one of <1> to <8> above.

[0265] <10> The electrode composite layer is a negative electrode composite layer containing a negative electrode active material. The method for manufacturing a laminate according to any one of <1> to <9> above.

[0266] <11> The electrode composite layer is formed on both sides of the solid electrolyte layer. The electrode composite layer formed on one side of the solid electrolyte layer is a positive electrode composite layer containing a positive electrode active material. The electrode composite layer formed on the other side of the solid electrolyte layer is a negative electrode composite layer containing a negative electrode active material. The method for manufacturing a laminate according to any one of <1> to <10> above.

[0267] <12> Having a positive electrode substrate, the positive electrode composite layer formed on the positive electrode substrate, the solid electrolyte layer formed on the positive electrode composite layer, and the negative electrode substrate formed on the solid electrolyte layer. The method for manufacturing a laminate according to any one of <1> to <11> above.

[0268] <13> A method for manufacturing an electrochemical element, comprising a step of forming a laminate by the method for manufacturing a laminate according to any one of <1> to <12> above.

[0269] <14> The method for manufacturing an electrochemical element according to <13> above, wherein the electrochemical element is a secondary battery.

[0270] As described above, the embodiments of the present invention have been described. However, the present invention is not limited to specific embodiments, and various modifications and changes are possible within the scope of the invention described in the claims.

Explanation of Reference Numerals

[0271] 1 Electrochemical element 1a Printing device 1b Storage container 1c Supply tube 3a Heating device 4 Printing substrate 5 Conveying unit 7 Liquid composition 8 Discharge engineering step 9 Heating engineering step 10 Positive electrode 11 Electrode substrate (positive electrode substrate) 11' Electrode substrate 11B Positive electrode substrate 12 Electrode composite layer 12' Solid electrolyte layer before pressing 12A Liquid composition 12B Positive electrode composite layer 13 Adhesive layer 15 Positive electrode 20 Negative electrode 21 Negative electrode substrate 22 Negative electrode composite layer 25 Negative electrode 30 Solid electrolyte layer 30B Solid electrolyte 40 Electrode element 41 Lead wire 42 Lead wire 51 Electrolyte layer 52 Exterior 100 Electrode 101 Laminate 102 Laminate 103 Electrode cell 104 Electrode cell 300 Liquid ejection device 300' Liquid ejection device 300A Liquid ejection device 300B Liquid ejection device 304 Feed roller 305 Take-up roller 306 Liquid ejection head 306A Liquid ejection head 306B Liquid ejection head 307 Tank 307A Tank 307B Tank 308 Tube 308A Tube 308B Tube 309 Heating mechanism 310 Stage 311 Valve 311A Valve 311B Valve 312 Valve 312A Valve 312B Valve 313 External tank 313A External tank 313B External tank 314 Valve 314A Valve 314B Valve 3101 Pump 3101A Pump 3101B Pump 400 Printing section 400' Printing section 401 Head 420 Inkjet Unit 422 Head Module 550 Moving Body 551 Motor 552 Electrochemical Element 553 Wheel 4000 Transfer Drum 4001 Intermediate Transfer Medium 4002 Pretreatment Unit 4003 Absorption Unit 4004 Heating Unit 4005 Cleaning Unit 4006 Intermediate Transfer Belt 4007 Heating Unit 4008 Cleaning Roller 4009a Driving Roller 4009b Opposing Roller 4009c Shape - Maintaining Roller 4009d Shape - Maintaining Roller 4009e Shape - Maintaining Roller 4009f Shape - Maintaining Roller 4009g Supporting Roller 621 Pressure Cylinder 622 Transfer Roller

Prior Art Documents

Patent Documents

[0272]

Patent Document 1

Patent Document 2

Claims

1. An electrode composite layer containing a solid electrolyte for an electrode composite layer and an electrode active material, and a solid electrolyte layer containing a solid electrolyte for a solid electrolyte layer formed on the electrode composite layer, the method for manufacturing a laminate having: a pre-pressurization solid electrolyte layer forming step of forming a pre-pressurization solid electrolyte layer, including applying a liquid composition containing components of the solid electrolyte layer onto the electrode composite layer before pressurization; a pressurization step of pressurizing the pre-pressurized laminate obtained in the pre-pressurization solid electrolyte layer forming step, wherein the solid electrolyte for the solid electrolyte layer contains sulfur element, In the step of forming the solid electrolyte layer before pressurization, the volume density of the electrode composite layer before pressurization to which the liquid composition is applied is 1.2 to 2.1 g / cm ３ is as follows: a method for manufacturing a laminate.

2. The solid electrolyte for the solid electrolyte layer is contained as particles in the laminate, wherein an average particle diameter of the particles is 0.1 to 20 μm, The method for manufacturing a laminate according to Claim 1.

3. In the pre-pressurization solid electrolyte layer forming step, the liquid composition is ejected by an inkjet head to form the solid electrolyte layer, The method for manufacturing a laminate according to Claim 1.

4. The liquid composition contains a dispersion medium, wherein a relative permittivity of the dispersion medium at 25°C is 7.0 or less, The method for manufacturing a laminate according to Claim 1.

5. Before the pre-pressurization solid electrolyte layer forming step, there is an electrode composite layer forming step of forming the electrode composite layer from a liquid composition containing components of the electrode composite layer, The method for manufacturing a laminate according to Claim 1.

6. In the electrode composite layer forming step, the liquid composition is ejected by an inkjet head to form the electrode composite layer, The method for manufacturing a laminate according to Claim 5.

7. The liquid composition containing components of the electrode composite layer contains a dispersion medium, wherein a relative permittivity of the dispersion medium at 25°C is 7.0 or less, The method for manufacturing a laminate according to Claim 5.

8. The electrode composite layer is formed on an electrode substrate, wherein an adhesive layer is formed between the electrode substrate and the electrode composite layer, The method for manufacturing a laminate according to Claim 1.

9. The electrode composite layer is a positive electrode composite layer containing a positive electrode active material, The method for manufacturing a laminate according to Claim 1.

10. The electrode composite layer is a negative electrode composite layer containing a negative electrode active material, The method for manufacturing a laminate according to Claim 1.

11. The electrode composite layers are formed on both surfaces of the solid electrolyte layer, the electrode composite layer formed on one surface of the solid electrolyte layer is a positive electrode composite layer containing a positive electrode active material, the electrode composite layer formed on the other surface of the solid electrolyte layer is a negative electrode composite layer containing a negative electrode active material, The method for manufacturing a laminate according to Claim 1.

12. A laminate having a positive electrode substrate, the positive electrode composite material layer formed on the positive electrode substrate, the solid electrolyte layer formed on the positive electrode composite material layer, and a negative electrode substrate formed on the solid electrolyte layer, The method for manufacturing a laminate according to claim 9.

13. A method for manufacturing an electrochemical element, comprising a step of forming a laminate by the method for manufacturing a laminate according to any one of claims 1 to 11.

14. The method for manufacturing an electrochemical element according to claim 13, wherein the electrochemical element is a secondary battery.

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