Method of manufacturing all-solid-state electrochemical element, all-solid-state electrochemical element and electric apparatus

Abstract

To provide a method of manufacturing an all-solid-state electrochemical element, with which stable manufacturing can be achieved, and the all-solid-state electrochemical element which is large in size and high in energy density and further includes an elastic layer absorbing variations in cell thickness during charging / discharging.SOLUTION: There is provided a method of manufacturing an all-solid-state electrochemical element. The all-solid-state electrochemical element includes a negative electrode having a negative electrode substrate, a positive electrode having a positive electrode substrate and a solid electrolyte layer provided between the negative electrode and the positive electrode, and further includes an elastic layer on a surface, of the negative electrode substrate and / or the positive electrode substrate, opposite to a surface where the solid electrolyte layer is present. The method includes an elastic layer formation step of forming the elastic layer. The elastic layer formation step includes a coating step of coating, with a liquid composition containing a polymerizable compound and a solvent, the negative electrode substrate and / or the positive electrode substrate, and a polymerization step of polymerizing the polymerizable compound. The elastic layer has a porous structure having a porosity of 20% or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing an all-solid-state electrochemical device, an all-solid-state electrochemical device, and an electric device. [Background technology]

[0002] In recent years, demand for lithium-ion secondary batteries for automotive applications is expected to expand due to the need for low environmental impact. Against this background, there is a demand for improved safety, higher energy density, and faster charging of lithium-ion secondary batteries, and active development is underway in all-solid-state lithium secondary batteries, which replace the existing liquid electrolyte with a solid electrolyte.

[0003] In all-solid-state lithium secondary batteries, high-capacity materials are often used for both the positive and negative electrodes in order to achieve high energy density, for example, high-nickel materials for the positive electrode and lithium or silicon for the negative electrode. Among these, high-capacity negative electrode materials have large fluctuations in film thickness during charge and discharge, which has caused problems in terms of their impact on battery characteristics (charge and discharge efficiency, cycle characteristics).

[0004] In response to this, Patent Documents 1 and 2 disclose that charge / discharge efficiency can be improved by providing an elastic portion (elastic layer) in the battery structure to absorb fluctuations in film thickness during charge / discharge.

[0005] The elastic parts (elastic layers) disclosed in Patent Documents 1 and 2 are both sheet-like members such as silicone rubber or acrylic sheets, but from the perspective of increasing energy density, the elastic parts (elastic layers) need to be made thinner, which poses a problem of increasing the complexity of the battery assembly process.

[0006] In Patent Document 1, an elastic part with a thickness of 50 μm is used, but the area is 1 cm 2 Furthermore, the thickness of the elastic layer disclosed in Patent Document 2 is as thick as 300 μm, and the structure is not capable of obtaining a high energy density.

[0007] In view of the above, there is a need for a method for manufacturing an all-solid-state electrochemical device that can be stably produced, and for an all-solid-state electrochemical device that is large, has a high energy density, and has an elastic layer that absorbs fluctuations in cell thickness during charge and discharge. Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a method for producing an all-solid-state electrochemical element that can be stably produced, and an all-solid-state electrochemical element that is large, has a high energy density, and has an elastic layer that absorbs fluctuations in cell thickness during charge and discharge. [Means for solving the problem]

[0009] The method for producing an all-solid-state electrochemical element of the present invention as a means for solving the above problems comprises the steps of: a negative electrode having a negative electrode substrate; a positive electrode having a positive electrode substrate; a solid electrolyte layer provided between the negative electrode and the positive electrode, A method for producing an all-solid-state electrochemical element further comprising an elastic layer on a surface of the negative electrode substrate and / or the positive electrode substrate opposite to a surface on which the solid electrolyte layer is present, an elastic layer forming step of forming the elastic layer, The elastic layer forming step includes a coating step of coating a liquid composition containing a polymerizable compound and a solvent onto the negative electrode substrate and / or the positive electrode substrate; a polymerization step of polymerizing the polymerizable compound, The elastic layer has a porous structure with a porosity of 20% or more.

[0010] The all-solid-state electrochemical device of the present invention as a means for solving the problems comprises: a negative electrode having a negative electrode substrate; a positive electrode having a positive electrode substrate; a solid electrolyte layer provided between the negative electrode and the positive electrode, The negative electrode substrate and / or the positive electrode substrate further includes an elastic layer on a surface opposite to the surface on which the solid electrolyte layer is present, The elastic layer has a porous structure with a porosity of 20% or more. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a method for producing an all-solid-state electrochemical device that can be stably produced, and an all-solid-state electrochemical device that is large, has a high energy density, and has an elastic layer that absorbs fluctuations in cell thickness during charge and discharge. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing an example of an elastic layer manufacturing apparatus (liquid ejection apparatus) for carrying out a manufacturing method of an all-solid-state electrochemical device according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing another example of an elastic layer manufacturing apparatus (liquid ejection apparatus) for carrying out the method for manufacturing an all-solid-state electrochemical device according to one embodiment of the present invention. [Figure 3] FIG. 3 is a schematic view showing yet another example of an elastic layer manufacturing apparatus (liquid ejection apparatus) for carrying out a method for manufacturing an all-solid-state electrochemical device according to one embodiment of the present invention. [Figure 4] FIG. 4 is a schematic cross-sectional view (part 1) showing an example of an all-solid-state electrochemical device according to one embodiment of the present invention. [Figure 5] FIG. 5 is a schematic cross-sectional view (part 2) showing an example of an all-solid-state electrochemical device according to one embodiment of the present invention. [Figure 6] FIG. 6 is a schematic cross-sectional view (part 3) showing an example of an all-solid-state electrochemical device according to one embodiment of the present invention. [Figure 7] FIG. 7 is a schematic cross-sectional view (part 4) showing an example of an all-solid-state electrochemical device according to one embodiment of the present invention. [Figure 8] FIG. 8 is a schematic cross-sectional view (part 5) showing an example of an all-solid-state electrochemical device according to one embodiment of the present invention. [Figure 9]FIG. 9 is a schematic cross-sectional view (part 6) showing an example of an all-solid-state electrochemical device according to one embodiment of the present invention. [Figure 10] FIG. 10 is a schematic cross-sectional view (part 7) showing an example of an all-solid-state electrochemical device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention is based on the inventors' intensive research and discovery of a porous film that can be directly coated onto a substrate by inkjet printing, and that has elastic behavior, meaning that even when pressed under high pressure, it will generally return to its original film thickness after the pressure is released. The porous membrane's elastic behavior allows it to be used as an elastic layer to absorb thickness fluctuations in cells during charge and discharge in all-solid-state electrochemical devices. The porous membrane absorbs thickness fluctuations during charge and discharge by collapsing its pores, which can significantly improve the charge and discharge efficiency and cycle characteristics of all-solid-state electrochemical devices without applying excessive stress. Furthermore, since porous films can be formed using inkjet printing, it is easy to control the film thickness, which is also highly effective in achieving high energy density. Furthermore, since the porous film can be formed by coating directly onto the substrate, it is possible to provide a method for producing an all-solid-state electrochemical device that can be stably produced even when it is applied as a thin elastic layer to a large cell.

[0014] The method for producing an all-solid-state electrochemical device and the all-solid-state electrochemical device of the present invention will be described in detail below.

[0015] (Method for manufacturing an all-solid-state electrochemical device, and an all-solid-state electrochemical device) The method for producing an all-solid-state electrochemical device of the present invention includes an elastic layer-forming step of forming an elastic layer, and the elastic layer-forming step includes a coating step of coating a liquid composition containing a polymerizable compound and a solvent onto an anode substrate and / or a cathode substrate, and a polymerization step of polymerizing the polymerizable compound. The all-solid-state electrochemical device of the present invention comprises a negative electrode having a negative electrode substrate, a positive electrode having a positive electrode substrate, a solid electrolyte layer, and an elastic layer, and may further comprise a negative electrode layer, a functional layer, etc. as required.

[0016] -Negative electrode- The negative electrode has a negative electrode substrate and may further have a negative electrode layer as required.

[0017] <Negative electrode substrate> The negative electrode substrate is also referred to as a negative electrode current collector foil. The material constituting the negative electrode substrate is not particularly limited as long as it has electronic conductivity and is stable against an applied potential, but examples thereof include metals such as copper, iron, chromium, and nickel, and alloys such as stainless steel.

[0018] The shape of the negative electrode substrate is not particularly limited, and examples thereof include a foil shape and a flat plate shape.

[0019] <Negative electrode layer> The negative electrode layer is not particularly limited and can be appropriately selected depending on the purpose. Examples of the material include a negative electrode composite layer containing lithium metal, graphite, and silicon.

[0020] <<Negative electrode composite layer>> The negative electrode mixture layer contains a negative electrode active material, a binder for the negative electrode mixture layer, and a conductive additive for the negative electrode mixture layer, and may further contain other components as necessary.

[0021] <<<Negative electrode active material>>> The negative electrode active material is not particularly limited as long as it is a material that can reversibly absorb and release alkali metal ions and can be appropriately selected depending on the purpose. For example, a carbon material containing graphite having a graphite-type crystal structure can be used. Examples of carbon materials include natural graphite, spherical or fibrous artificial graphite, non-graphitizable carbon (hard carbon), and easily graphitizable carbon (soft carbon). Examples of materials other than carbon materials include lithium titanate and titanium oxide. From the viewpoint of increasing the energy density of a lithium ion battery, high-capacity materials such as silicon, tin, silicon alloys, tin alloys, silicon oxide, silicon nitride, and tin oxide can also be suitably used as the negative electrode active material.

[0022] <<<Binder for negative electrode composite layer>>> The binder for the negative electrode mixture layer is not particularly limited as long as it is capable of binding the negative electrode materials together and the negative electrode material and the negative electrode substrate, and can be appropriately selected depending on the purpose.

[0023] Polymer compounds can be used as the binder for the negative electrode composite layer, including, for example, thermoplastic resins such as polyvinylidene fluoride (PVDF), acrylic resin, polyethylene, polypropylene, polyurethane, nylon, polytetrafluoroethylene, polyphenylene sulfide, polyethylene terephthalate, and polybutylene terephthalate, polyamide compounds, polyimide compounds, polyamideimide, ethylene-propylene-butadiene rubber (EPBR), styrene-butadiene rubber (SBR), nitrile butadiene rubber (NBR), isoprene rubber, polyisobutene, polyethylene glycol (PEO), polymethylmethacrylate (PMMA), and polyethylene vinyl acetate (PEVA).

[0024] <<<Conductive additive for negative electrode composite layer>>> The conductive additive for the negative electrode composite layer is not particularly limited and can be appropriately selected depending on the purpose. For example, carbon materials such as carbon black produced by a furnace method, an acetylene method, a gasification method, or the like, carbon nanofibers, carbon nanotubes, graphene, and graphite particles can be used. Examples of the conductive additive for the negative electrode composite layer other than the carbon material include metal particles such as aluminum, metal fibers, etc. The conductive additive may be preliminarily compounded with the negative electrode active material.

[0025] -Positive electrode- The positive electrode has a positive electrode substrate and may further have a positive electrode layer as required.

[0026] <Positive electrode base> The positive electrode substrate is also referred to as a positive electrode current collector foil. The material constituting the positive electrode substrate is not particularly limited as long as it has electronic conductivity and is stable against an applied potential, and examples thereof include metals such as aluminum and carbon-coated aluminum.

[0027] The shape of the positive electrode substrate is not particularly limited, and examples thereof include a foil shape and a flat plate shape.

[0028] <Positive electrode layer> The positive electrode layer is not particularly limited and can be appropriately selected depending on the purpose. For example, a positive electrode composite layer may be a mixture of a positive electrode active material, a solid electrolyte for the positive electrode composite layer, a binder for the positive electrode composite layer, a conductive additive for the positive electrode composite layer, etc.

[0029] <<Positive electrode composite layer>> The positive electrode mixture layer contains a positive electrode active material, a solid electrolyte for the positive electrode mixture layer, a binder for the positive electrode mixture layer, and a conductive additive for the positive electrode mixture layer, and may further contain other components as necessary.

[0030] <<<Cathode active material>>> There are no particular limitations on the positive electrode active material as long as it is capable of reversibly absorbing and releasing alkali metal ions, but alkali metal-containing transition metal compounds can be used. Examples of alkali metal-containing transition metal compounds include lithium-containing transition metal compounds such as composite oxides containing lithium and one or more elements selected from the group consisting of cobalt, manganese, nickel, chromium, iron, and vanadium. Examples of lithium-containing transition metal compounds include lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, and lithium nickel cobalt manganese oxide.

[0031] As the alkali metal-containing transition metal compound, a polyanionic compound having an XO4 tetrahedron (X=P, S, As, Mo, W, Si, etc.) in its crystal structure can also be used. Among these, lithium-containing transition metal phosphate compounds such as lithium iron phosphate and lithium vanadium phosphate are preferred in terms of cycle characteristics, and lithium vanadium phosphate is particularly preferred in terms of the lithium diffusion coefficient and the input / output characteristics of the electrochemical device. From the viewpoint of electron conductivity, the polyanionic compound is preferably composited by coating the surface with a conductive aid such as a carbon material.

[0032] <<<Solid electrolyte for positive electrode composite layer>>> The positive electrode composite layer solid electrolyte is a solid electrolyte contained in the positive electrode composite layer. The positive electrode composite layer solid electrolyte is not particularly limited, but is preferably a solid electrolyte containing elemental sulfur. The solid electrolyte containing elemental sulfur is, for example, a solid electrolyte containing sulfide (hereinafter referred to as a sulfide solid electrolyte).

[0033] Sulfide solid electrolytes can be broadly classified into crystalline sulfide solid electrolytes and glass-based solid electrolytes. These sulfide solid electrolytes are not particularly limited as long as they have ionic conductivity and no electronic conductivity. Furthermore, sulfide solid electrolytes are preferred because they have high plasticity, allowing for the formation of favorable interfaces between solid electrolyte particles or between the solid electrolyte and the active material. One type of sulfide solid electrolyte may be used alone, or two or more types may be used in combination.

[0034] The crystalline sulfide solid electrolyte is not particularly limited and can be appropriately selected depending on 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 2.1S 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 M2 x ] 1.35 P 1.65 S 12 (M1 and M2 are 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, Li6PS5X (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 (M is any of Si, Ge, and Sn, 0≦x≦1), Li7P2S8I, γ-Li3PS4, Li4MS4 (M is any 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 Examples include S4 (0≦x≦0.3).

[0035] The glass-based sulfide solid electrolyte is not particularly limited and can be appropriately selected depending on the purpose. Examples of the glass-based sulfide solid electrolyte include Li2S-P2S5, Li2S-P2S5-LiI, Li2S-P2S5-P2O5, Li2S-P2S5-LiCl, Li2S-SiS2, Li2S-SiS2-P2S5, Li2S-SiS2-Al2S3, and Li2S-SiS2-Li x MO y (M is Si, P, or Ge). Also, Li7P3S, in which a part of the glass-based sulfide solid electrolyte is crystallized, is used. 11 Glass ceramics can also be used. Here, the mixing ratio of the raw materials of the glass-based sulfide solid electrolyte is not important.

[0036] <<<Binder for positive electrode composite layer>>> The binder for the positive electrode mixture layer is not particularly limited as long as it is capable of binding the positive electrode materials together and the positive electrode material and the positive electrode substrate, and can be appropriately selected depending on the purpose.

[0037] Polymer compounds can be used as the binder for the positive electrode composite layer, including, for example, thermoplastic resins such as polyvinylidene fluoride (PVDF), acrylic resin, polyethylene, polypropylene, polyurethane, nylon, polytetrafluoroethylene, polyphenylene sulfide, polyethylene terephthalate, and polybutylene terephthalate, polyamide compounds, polyimide compounds, polyamideimide, ethylene-propylene-butadiene rubber (EPBR), styrene-butadiene rubber (SBR), nitrile butadiene rubber (NBR), isoprene rubber, polyisobutene, polyethylene glycol (PEO), polymethylmethacrylate (PMMA), and polyethylene vinyl acetate (PEVA).

[0038] <<<Conductive additive for positive electrode composite layer>>> The conductive additive for the positive electrode composite layer is not particularly limited and can be appropriately selected depending on the purpose. For example, carbon black produced by a furnace method, an acetylene method, a gasification method, or the like, or a carbon material such as carbon nanofibers, carbon nanotubes, graphene, or graphite particles can be used. Examples of the conductive additive for the positive electrode mixture layer other than the carbon material include metal particles such as aluminum, metal fibers, etc. The conductive additive may be preliminarily compounded with the positive electrode active material.

[0039] -Solid electrolyte layer- The solid electrolyte layer contains a solid electrolyte for a solid electrolyte layer, and may contain a binder for a solid electrolyte layer as needed.

[0040] <Solid electrolyte for solid electrolyte layer> The solid electrolyte for the solid electrolyte layer is a solid electrolyte contained in the solid electrolyte layer. The solid electrolyte for the solid electrolyte layer is not particularly limited, but is preferably a solid electrolyte containing elemental sulfur. The solid electrolyte containing elemental sulfur is, for example, a sulfide solid electrolyte. The solid electrolyte for the solid electrolyte layer may be the same type as the solid electrolyte for the positive electrode composite layer.

[0041] <Binder for solid electrolyte layer> The binder for the solid electrolyte layer is not particularly limited and can be appropriately selected depending on the purpose, and for example, a polymer compound can be used. Examples of the polymer compound include thermoplastic resins such as polyvinylidene fluoride (PVDF), acrylic resin, polyethylene, polypropylene, polyurethane, nylon, polytetrafluoroethylene, polyphenylene sulfide, polyethylene terephthalate, and polybutylene terephthalate, polyamide compounds, polyimide compounds, polyamideimide, ethylene-propylene-butadiene rubber (EPBR), styrene-butadiene rubber (SBR), nitrile butadiene rubber (NBR), isoprene rubber, polyisobutene, polyethylene glycol (PEO), polymethylmethacrylate (PMMA), and polyethylene vinyl acetate (PEVA).

[0042] -Function layer- The all-solid-state electrochemical device of the present invention may have a functional layer between the negative electrode substrate and the solid electrolyte layer.

[0043] The functional layer imparts various functions to the all-solid-state electrochemical device depending on the components of the functional layer. The material for the functional layer is not particularly limited and can be appropriately selected depending on the purpose, but an example thereof is a silver-carbon mixed film having a lithium dendrite suppressing function.

[0044] -Elastic layer and elastic layer forming process- The elastic layer of the present invention is provided on the negative electrode substrate and / or the positive electrode substrate on the side opposite to the side on which the solid electrolyte layer is present, and has a porous structure. The elastic layer having a porous structure absorbs thickness fluctuations of the cell during charge and discharge by collapsing its pores, thereby preventing unnecessary stress from being applied to the all-solid-state electrochemical device and making it possible to significantly improve the charge and discharge efficiency and cycle characteristics.

[0045] The porous structure is preferably a bicontinuous structure with a resin skeleton. Here, "bicontinuous structure" means a structure in which two or more substances or phases each have a continuous structure and do not form an interface, and in this embodiment, it means a structure in which the resin phase and the pore phase are both three-dimensional branched network continuous phases. These structures can be formed, for example, by polymerization-induced phase separation with a polymerizable compound that is a precursor of the elastic layer (see, for example, JP 2003-1911628 A, WO 97-044363 A, JP 2005-298757 A, JP 2010-513589 A, JP 2001-163907 A, and JP 2001-138504 A).

[0046] Polymerization-induced phase separation refers to a state in which the polymerizable compound and solvent are compatible before the start of polymerization, but after the start of polymerization, the polymer (resin) produced during the polymerization process is no longer compatible with the solvent, resulting in phase separation. While there are other methods for obtaining porous structures through phase separation, the co-continuous porous structure obtained by polymerization-induced phase separation has the advantage of being highly resistant to chemicals and heat. Furthermore, compared to other methods, it has the advantage of shorter process time and easier surface modification.

[0047] Next, we will explain the process of forming a porous structure using a liquid composition containing a polymerizable compound by polymerization-induced phase separation. The polymerizable compound undergoes a polymerization reaction when irradiated with light or the like to form a resin. During this process, the solubility of the growing resin in the solvent decreases, causing phase separation between the resin and the solvent. Ultimately, the resin forms a porous structure with a co-continuous structure due to the resin skeleton, with the solvent filling the pores. When this is dried, the solvent is removed, leaving behind a porous resin with a co-continuous structure of a three-dimensional network structure.

[0048] A method for confirming that the elastic layer has a bicontinuous structure and that the pores are interconnected includes, for example, observing an image of the cross section of the elastic layer using a scanning electron microscope (SEM) or the like to confirm that the pores are interconnected. [An example of image observation using a scanning electron microscope (SEM)] After staining the elastic layer with osmium, it is vacuum-impregnated with epoxy resin, and the internal cross-sectional structure is cut out using a focused ion beam (FIB) and observed using a scanning electron microscope (SEM).

[0049] The elastic layer is formed by an elastic layer forming step, which includes a coating step and a polymerization step, and may further include other steps as necessary.

[0050] <Coating process> In the coating step, a liquid composition containing a polymerizable compound and a solvent is coated onto the negative electrode substrate and / or the positive electrode substrate.

[0051] The method for applying the liquid composition onto the negative electrode substrate and / or the positive electrode substrate is not particularly limited and can be appropriately selected depending on the purpose. However, it is preferable to apply the liquid composition by any one of an inkjet method, a die coating method, a spin coating method, and a spray coating method, since the film thickness of the elastic layer can be easily controlled.

[0052] <<Liquid composition>> The liquid composition contains a polymerizable compound and a solvent.

[0053] <<<Polymerizable compound>>> The polymerizable compound of the present invention is preferably a compound represented by general formula (1) or general formula (2) from the viewpoint of suppressing curling of the elastic layer. [ka] (In the general formula (1), R1 represents a hydrogen atom or a methyl group, and R2 represents any one selected from a polyester chain, a polyalkylene oxide chain, an alkyl chain, and an acrylic polymer ester derivative.) [ka] (In the general formula (2), R3 and R4 represent a hydrogen atom or a methyl group.)

[0054] In general formula (1), r is preferably 2 or 3, and more preferably 2, from the viewpoint of suppressing curling of the elastic layer.

[0055] In this specification, the polymerizable compound means a compound having a plurality of vinyl groups capable of radical polymerization, and is preferably a compound having an acrylic group from the viewpoint of high-speed polymerization by an electron beam, i.e., R1 in general formula (1) and R3 and R4 in general formula (2) are preferably hydrogen atoms. Generally, acrylic groups have high radical polymerizability, so that by using a photopolymerization initiator or a thermal polymerization initiator in combination, a cured product can be obtained in a short time. Although a cured product can be obtained without using a polymerization initiator in combination, when a polymerizable compound having an acrylic group is used, that is, when R1 in general formula (1) and R3 and R4 in general formula (2) are hydrogen atoms, from the viewpoint of polymerization rate and equipment cost, it is preferable to use a polymerizable compound in combination with a thermal polymerization initiator or a photopolymerization initiator, and it is more preferable to use a polymerizable compound in combination with a photopolymerization initiator.

[0056] Examples of the polymerizable compound represented by general formula (1) or general formula (2) include hydroxypivalic acid neopentyl glycol acrylic acid adduct, bifunctional acrylic acid polymer ester acrylate, bifunctional caprolactam-modified acrylate, and polyester acrylate.

[0057] Specific examples of the hydroxypivalic acid neopentyl glycol acrylic acid adduct include, by trade name, Light Acrylate HPP-A (manufactured by Kyoeisha Chemical Co., Ltd.), Viscoat #195 (manufactured by Osaka Organic Chemical Industry Ltd.), Viscoat #230 (manufactured by Osaka Organic Chemical Industry Ltd.), Viscoat #260 (manufactured by Osaka Organic Chemical Industry Ltd.), Miramer M210 (manufactured by Miwow), Miramer M216 (manufactured by Miwow), and KAYARAD FM-400 (manufactured by Nippon Kayaku Co., Ltd.).

[0058] A specific example of the bifunctional acrylic acid polymer ester acrylate is Viscoat #230D (manufactured by Osaka Organic Chemical Industry Ltd.) under the trade name.

[0059] Specific examples of bifunctional caprolactam-modified acrylates include trade names such as KAYARAD HX-220 (manufactured by Nippon Kayaku Co., Ltd.) and KAYARAD HX-620 (manufactured by Nippon Kayaku Co., Ltd.).

[0060] Specific examples of polyester acrylate include trade names such as CN2273 (manufactured by Tomoe Engineering Co., Ltd.) and CN2283 (manufactured by Tomoe Engineering Co., Ltd.).

[0061] The polymerizable compound in the present invention may contain only a polymerizable compound represented by general formula (1) or general formula (2), or may contain two or more different polymerizable compounds represented by general formula (1) or general formula (2). In either case, in addition to the polymerizable compound represented by general formula (1) or general formula (2), a polymerizable compound that does not satisfy general formula (1) or general formula (2) may also be contained. Here, from the viewpoint of being able to suppress deterioration of the solid electrolyte layer, it is preferable that the polymerizable compound in the present invention does not contain a polymerizable compound that does not satisfy general formula (1) or general formula (2). Furthermore, from the viewpoint of being able to expand the range in which the physical properties (e.g., elastic modulus) of the elastic layer can be controlled, it is preferable that the polymerizable compound in the present invention contains two or more different polymerizable compounds represented by general formula (1) or general formula (2).

[0062] The photopolymerization initiator is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include alkylphenone-based polymerization initiators, acylphosphine sulfite-based polymerization initiators, and oxime ester-based polymerization initiators. Specific examples of the alkylphenone polymerization initiator, by trade name, include Omnirad 651 (manufactured by IGM Resins BV), Omnirad 184 (manufactured by IGM Resins BV), Omnirad 1173 (manufactured by IGM Resins BV), Omnirad 2959 (manufactured by IGM Resins BV), Omnirad 127 (manufactured by IGM Resins BV), Omnirad 907 (manufactured by IGM Resins BV), Omnirad 369 (manufactured by IGM Resins BV), Omnirad 369E (manufactured by IGM Resins BV), and Omnirad 379EG (manufactured by IGM Resins BV). Specific examples of the acylphosphine sulfite polymerization initiator include trade names such as Omnirad TPO (manufactured by IGM Resins BV) and Omnirad 819 (manufactured by IGM Resins BV). Specific examples of the oxime ester polymerization initiator include, by trade name, Irgacure OXE01 (manufactured by BASF Japan), Irgacure OXE02 (manufactured by BASF Japan), Irgacure OXE03 (manufactured by BASF Japan), and Irgacure OXE04 (manufactured by BASF Japan).

[0063] The content of the polymerization initiator is not particularly limited and can be appropriately selected depending on the purpose. However, from the viewpoint of obtaining a sufficient curing rate, the content is preferably 0.05% by mass or more and 10.0% by mass or less, and more preferably 0.1% by mass or more and 5.0% by mass or less, when the total amount of the polymerizable compounds is taken as 100.0% by mass.

[0064] <<<Solvent>>> The solvent in the liquid composition is expected to act as a buffer against cure shrinkage because there is no change in the intermolecular distance between the solvents or between the resin and the solvent during polymerization.

[0065] The solvent means an organic solvent having a water content of 1 wt % or less, and specific examples thereof include aromatic hydrocarbons such as toluene, xylene, mesitylene, anisole, and phenetole; hydrocarbon solvents such as hexane, heptane, nonane, octane, decane, menthane, cyclohexane, cyclooctane, and p-menthane; ethyl butyrate, ethyl valerate, ethyl hexanoate, ethyl heptanoate, ethyl octanoate, ethyl nonanoate, ethyl decanoate, ethyl undecanoate, ethyl laurate, methyl butyrate, methyl valerate, methyl hexanoate, methyl heptanoate, and methyl octanoate. Examples of suitable solvents include ester-based solvents such as methyl nonanoate, methyl decanoate, methyl undecanoate, methyl laurate, ethyl isovalerate, isoamyl acetate, isobutyl isobutyrate, methyl 3-methoxyisobutyrate, butyl isobutyrate, isobutyl isovalerate, butyl 2-methylbutyrate, butyl isovalerate, heptyl acetate, isoamyl isovalerate, 2-ethylhexyl acetate, hexyl butyrate, ethyl benzoate, hexyl hexanoate, amyl n-octanoate, and hexyl acetate; petroleum-based mixed solvents; ethanol, isopropyl alcohol, hexanol, and octanol.

[0066] Examples of petroleum-based mixed solvents include trade names such as ISOPAR E, ISOPAR G, ISOPAR H, ISOPAR H BHT, ISOPAR L, ISOPAR M, EXXSOL D40, EXXSOL D80, EXXSOL D110, EXXSOL D130, EXXSOL DSP80 / 100, and EXXSOL DSP145 / 60 (all manufactured by Ando Bara Chemie Co., Ltd.).

[0067] The content of the solvent is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of the curl suppression effect, it is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more, based on the total amount of the liquid composition. Furthermore, from the viewpoint of film thickness control, it is preferably 80% by mass or less.

[0068] In view of the diversity of the selection of polymerizable compounds, a plurality of solvents can be used in combination.

[0069] From the viewpoint of the effect of suppressing curling due to volume shrinkage, the solvent in the liquid composition is preferably a mixed solvent containing a good solvent and a poor solvent, and satisfies formula (1).

[0070]

number

[0071] In this specification, a "good solvent" refers to a solvent in which a polymerizable compound is soluble. In this specification, a "poor solvent" refers to a solvent in which a polymerizable compound is insoluble. In addition, in this specification, a "mixed solvent" refers to a solvent containing a good solvent and a poor solvent. In this specification, the "mixing ratio X" is the content ratio of the good solvent in the mixed solvent expressed as a percentage based on the mass of the good solvent. In this specification, the "solubility point of a polymerizable compound" refers to the minimum content ratio, expressed as a percentage, based on the mass of a good solvent in a mixed solvent in which the polymerizable compound is soluble.

[0072] In this specification, "soluble" refers to a property in which a mixture of a solvent and a polymerizable compound does not become cloudy or undergo phase separation after being ultrasonically stirred for 15 minutes using an ultrasonic stirrer (USS-1) and then allowed to stand for 10 minutes at a predetermined temperature. The predetermined temperature is not particularly limited as long as it is the environmental temperature during actual use, and may be, for example, 25°C. The solubility / insolubility is determined depending on the composition of the liquid composition, for example, the following patterns 1 and 2.

[0073] [Pattern 1] In the case of a liquid composition containing one polymerizable compound represented by general formula (1) or general formula (2) and two solvents (mixed solvent), the solubility / insolubility is determined based on the solvent ratio (mass ratio) in the liquid composition containing 10 g of the mixed solvent and 1 g of the polymerizable compound represented by general formula (1) or general formula (2).

[0074] [Pattern 2] In the case of a liquid composition containing two polymerizable compounds (mixed compounds) represented by general formula (1) or general formula (2) and two solvents (mixed solvents), the solubility / insolubility is determined based on the solvent ratio (mass ratio) in a liquid composition containing 10 g of mixed solvent and 1 g of mixed compound.

[0075] Equation (1) can also be transformed into equation (1)'.

[0076]

number

[0077] When the liquid composition satisfies formula (1) or formula (1)', a resin layer having a high porosity can be formed based on the phase separation rate, thereby suppressing volumetric shrinkage during hardening of the liquid composition and forming a high-quality resin layer. As the value of "mixing ratio X-solubility point of polymerizable compound" in formula (1)' approaches 0, curling due to volume shrinkage can be more effectively suppressed.

[0078] The method for producing the liquid composition is not particularly limited and can be appropriately selected depending on the purpose. For example, the liquid composition can be produced through a step of mixing a polymerizable compound, a step of mixing the polymerizable compound with a solvent, a step of dissolving a polymerization initiator in the solvent, and a stirring step.

[0079] <Polymerization process> The polymerization step is a step of applying heat or light to the liquid composition to polymerize the polymerizable compound. By applying heat or light to the liquid composition, the polymerizable compound in the liquid composition polymerizes and polymerization-induced phase separation occurs, thereby obtaining an elastic layer having a porous structure.

[0080] The light used in the polymerization step is preferably active energy rays. The active energy rays may be any rays capable of imparting the energy necessary to promote the polymerization reaction of the polymerizable compound in the liquid composition, and are not particularly limited. Examples include ultraviolet rays, electron beams, α rays, β rays, γ rays, and X-rays. Among these, ultraviolet rays are preferred. In particular, when a high-energy light source is used, the polymerization reaction can be promoted without using a polymerization initiator.

[0081] The irradiation intensity of the active energy rays is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 1 W / cm 2 Preferably, it is 300 mW / cm or less. 2 More preferably, it is 100 mW / cm or less. 2 It is even more preferable that: If the irradiation intensity of the active energy rays is too low, polymerization-induced phase separation will proceed excessively, which will cause variations in the porous structure and coarsening. In addition, the irradiation time will be long, which will reduce productivity. Therefore, it is recommended to use an irradiation intensity of 10 mW / cm 2 It is preferable that the power is 30 mW / cm or more. 2 More preferably, it is equal to or greater than this.

[0082] The elastic layer obtained in the elastic layer forming step preferably contains a structural unit represented by the following general formula (3) or (4), from the viewpoint of suppressing curling of the elastic layer. [ka] (In the general formula (3), R6 represents a hydrogen atom or a methyl group, and R7 represents any one selected from a polyester chain, a polyalkylene oxide chain, an alkyl chain, and an acrylic polymer ester derivative.) [ka] (In the general formula (4), R8 and R9 represent a hydrogen atom or a methyl group.)

[0083] R6 in the structural unit represented by general formula (3) and R8 and R9 in the structural unit represented by general formula (4) are preferably hydrogen atoms, from the viewpoints of being able to lower the glass transition temperature, improve flexibility, and suppress curling.

[0084] From the viewpoint of further suppressing deterioration of the solid electrolyte layer, the elastic layer in the present invention preferably contains a structural unit in which R7 in general formula (3) is a polyester chain or a structural unit represented by general formula (4), more preferably contains a structural unit in which R7 in general formula (3) is a polyester chain, and further preferably contains a structural unit in which R7 in general formula (3) is a polycaprolactone chain.

[0085] There are no particular restrictions on n in the structural unit represented by general formula (3), and it can be appropriately selected within a range that does not impair the effects of the present invention. For example, n may be an integer of 2 to 1,000. There are no particular restrictions on m in the structural unit represented by general formula (3), and it can be appropriately selected within a range that does not impair the effects of the present invention. There are no particular restrictions on p and q in the structural unit represented by general formula (4) and they can be appropriately selected within a range that does not impair the effects of the present invention. For example, they can be integers from 2 to 1000.

[0086] The elastic layer may contain at least one structural unit represented by general formula (3) or general formula (4). That is, the elastic layer may contain only structural units represented by general formula (3) or general formula (4), or may contain two or more different structural units represented by general formula (3) or general formula (4). In either case, in addition to the structural units represented by general formula (3) or general formula (4), the elastic layer may also contain structural units that do not satisfy general formula (3) or general formula (4). The elastic layer preferably contains two or more different structural units represented by general formula (3) or general formula (4), from the viewpoint of being able to expand the range in which the physical properties (e.g., elastic modulus) of the elastic layer can be controlled.

[0087] The elastic layer is a layer that has elastic behavior such that even when compressed by a high pressure press at room temperature (25° C.), it recovers to a thickness at least equal to or greater than the thickness at the time of compression after the press is released. When the elastic modulus is defined by the following formula (2) using the film thickness of the elastic layer at 25°C before pressing (film thickness before pressing) and the film thickness of the elastic layer after pressing the elastic layer at 25°C at 500 MPa for 5 minutes and then releasing the press for 5 minutes (film thickness after pressing), the elastic modulus of the elastic layer is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more in terms of cycle characteristics.Preferred pressing methods include cold isostatic pressing (CIP), uniaxial pressing, and roll pressing.

number

[0088] The porosity of the elastic layer is 20% or more, preferably 30% or more, and is preferably 80% or less, more preferably 70% or less. By setting the porosity of the elastic layer to 20% or more, curling of the elastic layer can be suppressed, enabling stable production of all-solid-state electrochemical devices. Furthermore, the elastic layer has sufficient elasticity to absorb fluctuations in cell thickness during charge and discharge, significantly improving charge and discharge efficiency and cycle characteristics. When the porosity of the elastic layer is 80% or less, the strength of the elastic layer can be improved, which is preferable. The porosity of the elastic layer can be measured by the same method as described in the section [Example of image observation method using a scanning electron microscope (SEM)].

[0089] The thickness t0 of the elastic layer is preferably 1 μm or more to ensure that the elastic layer has a thickness sufficient to absorb thickness variations of the cell during charge and discharge. More preferably, when the porosity of the elastic layer is ε and the thickness increase of the all-solid-state electrochemical device during charge is t1, t0 > t1 / ε is satisfied. Furthermore, in order to improve the energy density of the all-solid-state electrochemical device, t0 is preferably 200 μm or less, and more preferably 100 μm or less.

[0090] The air permeability of the elastic layer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1,000 seconds / 100 mL or less, more preferably 500 seconds / 100 mL or less, and even more preferably 300 seconds / 100 mL or less. The air permeability is measured in accordance with JIS P8117, and can be measured, for example, using a Gurley densometer (manufactured by Toyo Seiki Seisakusho, Ltd.) For example, an air permeability of 1,000 seconds / 100 mL or less may be used to determine that the pores are interconnected.

[0091] The cross-sectional shape of the pores in the elastic layer is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a substantially circular shape, a substantially elliptical shape, and a substantially polygonal shape. Here, the size of the pores refers to the length of the longest part in the cross-sectional shape of the elastic layer. The size of the pores in the elastic layer can be determined, for example, from a cross-sectional photograph taken with a scanning electron microscope (SEM).

[0092] The size of the pores in the elastic layer is not particularly limited and can be appropriately selected depending on the purpose.

[0093] The method for controlling the size and porosity of the pores in the elastic layer is not particularly limited and can be appropriately selected depending on the purpose. Examples include a method for adjusting the content of the polymerizable compound in the liquid composition, a method for adjusting the content of the solvent in the liquid composition, and a method for adjusting the irradiation conditions of the active energy rays.

[0094] The volume resistance value of the elastic layer is not particularly limited and can be appropriately selected depending on the purpose. When the all-solid-state electrochemical device has a bipolar structure, the volume resistance value of the elastic layer is preferably low. 7 It is preferable that the resistivity is Ω·cm or less.

[0095] <Other processes> The other steps are not particularly limited and can be appropriately selected depending on the purpose as long as they do not impair the effects of the present invention, and examples thereof include a solvent removal step.

[0096] <<Solvent removal process>> The solvent removal step is a step of removing the solvent from the elastic layer. The solvent removal step is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a method of removing the solvent from the elastic layer by heating. In this case, heating under reduced pressure is preferred because it promotes solvent removal and can reduce the amount of solvent remaining in the elastic layer. Heating may be performed using a stage, or using a heating mechanism other than a stage. The heating mechanism may be installed either above or below the substrate, or multiple heating mechanisms may be installed. There are no particular limitations on the heating mechanism, and examples include a resistance heater, an infrared heater, and a fan heater. There are no particular limitations on the heating temperature, but from the viewpoint of energy use, a temperature of 70°C to 150°C is preferred.

[0097] Here, an embodiment of the method for producing an all-solid-state electrochemical device and the all-solid-state electrochemical device of the present invention will be described with reference to the drawings, although the present invention is not limited to these embodiments.

[0098] FIG. 1 is a schematic diagram showing an example of an elastic layer manufacturing apparatus (liquid ejection apparatus) for carrying out a manufacturing method of an all-solid-state electrochemical device according to one embodiment of the present invention. The elastic layer manufacturing apparatus 500 includes a conveying section 5, a printing section 100, a polymerizing section 200, a heating section 300, and a roller 7.

[0099] The transport unit 5 transports the printing substrate at a preset speed in the order of the printing unit 100, the polymerization unit 200, and the heating unit 300. Here, an example will be described in which a negative electrode substrate is used as the printing substrate. The negative electrode substrate may be a substrate having a negative electrode composite material layer provided thereon, or may be a substrate having no negative electrode composite material layer. In the case of a substrate having no negative electrode composite material layer, the negative electrode composite material layer may be provided after forming the elastic layer.

[0100] -Printing Department 100- The printing unit 100 includes a printing device 1a that ejects a liquid composition 6, a storage container 1b that stores the liquid composition 6, and a supply tube 1c that supplies the liquid composition 6 stored in the storage container 1b to the printing device 1a.

[0101] The printing unit 100 ejects the liquid composition 6 from the printing device 1a onto a printing substrate to form a thin film of the liquid composition 6. The storage container 1b may be integrated with the elastic layer manufacturing device or may be detachable from the elastic layer manufacturing device. Alternatively, the storage container 1b may be a container used for adding the liquid composition to a storage container integrated with the elastic layer manufacturing device or a storage container detachable from the elastic layer manufacturing device.

[0102] The storage container 1b and the supply tube 1c are not particularly limited as long as they can stably store and supply the liquid composition 6, and can be appropriately selected depending on the purpose. The materials constituting the storage container 1b and the supply tube 1c preferably have a light-blocking property in the relatively short wavelength region of ultraviolet light and visible light, which is preferable because this prevents the liquid composition 6 from being polymerized by external light.

[0103] - Polymerization section 200 - As shown in FIG. 1, in the case of photopolymerization, the polymerization section 200 has a light irradiation device 2a that irradiates light to carry out the polymerization process, and a polymerization inert gas circulation device 2b that circulates a polymerization inert gas.

[0104] The light irradiation device 2a irradiates the thin film of the liquid composition formed by the printing unit 100 with light in the presence of a polymerizable inert gas, and photopolymerizes it to obtain an elastic layer precursor. The light irradiation device 2a is not particularly limited as long as it can initiate and progress polymerization of the compound in the liquid composition, and can be appropriately selected depending on the absorption wavelength of the photopolymerization initiator contained in the liquid composition, and examples include ultraviolet light sources such as high-pressure mercury lamps, metal halide lamps, hot cathode tubes, cold cathode tubes, and LEDs. However, since the shorter the wavelength of the irradiated light, the more likely it is that it will reach deeper parts, it is preferable to select a light source depending on the thickness of the elastic layer to be formed.

[0105] The polymerization inert gas circulation device 2b plays a role in preventing inhibition of the polymerization reaction of the polymerizable compound present near the surface of the liquid composition by reducing the concentration of oxygen having polymerization activity contained in the atmosphere. Examples of the polymerization inert gas include nitrogen, carbon dioxide, and argon. The O2 concentration in the polymerization inert gas is preferably less than 20% (an environment with a lower oxygen concentration than the atmosphere), more preferably 0% to 15%, and even more preferably 0% to 5% in order to obtain a greater inhibition reduction effect. Furthermore, the polymerization inert gas circulation device 2b is preferably provided with a temperature control means capable of adjusting the temperature in order to realize stable conditions for the polymerization to proceed.

[0106] In the case of thermal polymerization, the polymerization section 200 may be a heating device. The heating device is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a substrate heater (e.g., a hot plate), an IR heater, and a hot air heater, and these may be used in combination. The heating temperature, time, and light irradiation conditions can be appropriately selected depending on the polymerizable compound contained in the liquid composition and the thickness of the formed film.

[0107] The polymerization unit 200 is not particularly limited and can be appropriately selected depending on the purpose, such as the polymerization initiator used and the polymerization method. For example, in the case of photopolymerization, a light irradiation device that irradiates ultraviolet light with a wavelength of 365 nm for 3 seconds, and in the case of thermal polymerization, a heating device that heats at 150°C in vacuum drying for 12 hours, etc. can be used.

[0108] -Heating section 300- The heating section 300 has a heating device 3a that performs the solvent removal step. 1, the heating device 3a heats the elastic layer precursor formed in the polymerization section 200 to dry and remove the remaining solvent. At this time, the solvent removal may be performed under reduced pressure.

[0109] The heating section 300 also performs a polymerization promotion step in which the elastic layer precursor is heated by the heating device 3a to further promote the curing (polymerization) reaction carried out in the polymerization section 200, and an initiator removal step in which the photopolymerization initiator remaining in the elastic layer precursor is heated by the heating device 3a to dry and remove it. Note that these polymerization promotion step and initiator removal step do not have to be performed simultaneously with the solvent removal step, and may be performed before or after the solvent removal step. After the solvent removal step, the heating section 300 performs a polymerization completion step of heating the elastic layer under reduced pressure.

[0110] FIG. 2 is a schematic diagram showing another example of an elastic layer manufacturing apparatus (liquid ejection apparatus) for carrying out the method for manufacturing an all-solid-state electrochemical device according to one embodiment of the present invention. The liquid ejection device 300 ′ controls the pump 310 and the valves 311 and 312 to allow the liquid composition to circulate through the liquid ejection head 306 , the liquid ejection head tank 307 , and the tube 308 . The liquid ejection device 300' is provided with an external tank 313, and when the liquid composition in the liquid ejection head tank 307 decreases, it is possible to supply the liquid composition from the external tank 313 to the tank 307 by controlling the pump 310 and the valves 311, 312, and 314.

[0111] By using the elastic layer manufacturing device, the liquid composition can be ejected onto a target object.

[0112] The elastic layer manufacturing apparatus 500 may be provided with a mechanism for capping the nozzle to prevent the liquid composition 6 from drying out when it is not being ejected from the liquid ejection head.

[0113] FIG. 3 is a schematic view showing yet another example of an elastic layer manufacturing apparatus (liquid ejection apparatus) for carrying out a method for manufacturing an all-solid-state electrochemical device according to one embodiment of the present invention. Liquid ejection device 300A' and liquid ejection device 300B' may be used in combination. That is, the tanks may supply the liquid composition from external tanks 313A and 313B connected to tanks 307A and 307B, and the liquid ejection head may have multiple heads 306A and 306B. Accordingly, tubes 308A and 308B, valves 311A, 311B, 312A, 312B, valves 314A and 314B, and pumps 310A and 310B may be provided.

[0114] FIG. 4 is a schematic cross-sectional view (part 1) showing an example of an all-solid-state electrochemical device according to one embodiment of the present invention.

[0115] The all-solid-state electrochemical element 20a is formed by laminating an elastic layer 11, an anode substrate 12, an anode layer 13, a functional layer 14, a solid electrolyte layer 15, a cathode layer 16, and a cathode substrate 17 in this order. In the all-solid-state electrochemical element 20d, the anode 18 is composed of the anode substrate 12 and the anode layer 13, and the cathode 19 is composed of the cathode layer 16 and the cathode substrate 17. The anode layer 13 can be, for example, an anode composite layer. The functional layer 14 can be appropriately selected depending on the function to be imparted to the all-solid-state electrochemical element 20a. The positive electrode layer 16 can be, for example, a cathode composite layer. By providing the elastic layer 11 on the anode substrate 12, fluctuations in cell thickness during charge and discharge are absorbed, thereby preventing unnecessary stress from being applied to the all-solid-state electrochemical element, and significantly improving charge and discharge efficiency and cycle characteristics. As in the all-solid-state electrochemical device 20a, both the negative electrode layer 13 and the functional layer 14 may be provided.

[0116] FIG. 5 is a schematic cross-sectional view (part 2) showing an example of an all-solid-state electrochemical device according to one embodiment of the present invention.

[0117] The all-solid-state electrochemical element 20b is formed by laminating, in this order, an elastic layer 11, an anode substrate 12, a solid electrolyte layer 15, a cathode layer 16, and a cathode substrate 17. In the all-solid-state electrochemical element 20b, the anode 18 is composed of only the anode substrate 12, and the cathode 19 is composed of the cathode layer 16 and the cathode substrate 17.

[0118] FIG. 6 is a schematic cross-sectional view (part 3) showing an example of an all-solid-state electrochemical device according to one embodiment of the present invention.

[0119] The all-solid-state electrochemical element 20c is formed by laminating, in this order, an elastic layer 11, an anode substrate 12, an anode layer 13, a solid electrolyte layer 15, a cathode layer 16, and a cathode substrate 17. In the all-solid-state electrochemical element 20c, the anode 18 is composed of the anode substrate 12 and the anode layer 13, and the cathode 19 is composed of the cathode layer 16 and the cathode substrate 17.

[0120] FIG. 7 is a schematic cross-sectional view (part 4) showing an example of an all-solid-state electrochemical device according to one embodiment of the present invention.

[0121] The all-solid-state electrochemical element 20d is formed by laminating, in this order, an elastic layer 11, an anode substrate 12, a functional layer 14, a solid electrolyte layer 15, a cathode layer 16, and a cathode substrate 17. In the all-solid-state electrochemical element 20d, the anode 18 is composed of only the anode substrate 12, and the cathode 19 is composed of the cathode layer 16 and the cathode substrate 17.

[0122] FIG. 8 is a schematic cross-sectional view (part 5) showing an example of an all-solid-state electrochemical device according to one embodiment of the present invention.

[0123] The all-solid-state electrochemical element 20e is formed by laminating an anode substrate 12, an anode layer 13, a functional layer 14, a solid electrolyte layer 15, a cathode layer 16, a cathode substrate 17, and an elastic layer 11 in this order. In the all-solid-state electrochemical element 20e, the anode 18 is composed of the anode substrate 12 and the anode layer 13, and the cathode 19 is composed of the cathode layer 16 and the cathode substrate 17. As in the all-solid-state electrochemical element 20e, the elastic layer 11 may be provided on the cathode substrate 17.

[0124] FIG. 9 is a schematic cross-sectional view (part 6) showing an example of an all-solid-state electrochemical device according to one embodiment of the present invention.

[0125] The all-solid-state electrochemical element 20f is formed by laminating an elastic layer 11, an anode substrate 12, an anode layer 13, a functional layer 14, a solid electrolyte layer 15, a cathode layer 16, a cathode substrate 17, and an elastic layer 11 in this order. In the all-solid-state electrochemical element 20f, the anode 18 is composed of the anode substrate 12 and the anode layer 13, and the cathode 19 is composed of the cathode layer 16 and the cathode substrate 17. As in the all-solid-state electrochemical element 20f, the elastic layer 11 may be provided on both the anode substrate 12 and the cathode substrate 17.

[0126] FIG. 10 is a schematic cross-sectional view (part 7) showing an example of an all-solid-state electrochemical device according to one embodiment of the present invention.

[0127] The all-solid-state electrochemical element 20g is formed by stacking an elastic layer 11, an anode substrate 12, an anode layer 13, a functional layer 14, a solid electrolyte layer 15, a cathode layer 16, a cathode substrate 17, a cathode layer 16, a solid electrolyte layer 15, a functional layer 14, an anode layer 13, and an anode substrate 12 in this order. In the all-solid-state electrochemical element 20g, the anode 18 is composed of the anode substrate 12 and the anode layer 13, and the cathode 19 is composed of two cathode layers 16 and the cathode substrate 17. When the all-solid-state electrochemical element 20g is used as a unit cell, further unit cells may be stacked. There is no particular limitation on the number of unit cells stacked, and the number may be selected appropriately depending on the purpose.

[0128] (Applications of all-solid-state electrochemical devices) The all-solid-state electrochemical device of the present invention can be suitably used as a secondary battery. The secondary battery in which the all-solid-state electrochemical device is used is preferably a lithium-ion secondary battery.

[0129] The use of the all-solid-state electrochemical element is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include mobile objects such as vehicles, smartphones, notebook computers, pen-input personal computers, mobile personal computers, e-book players, mobile phones, mobile fax machines, mobile copiers, mobile printers, headphone stereos, video movie players, LCD televisions, handheld vacuum cleaners, portable CDs, minidiscs, transceivers, electronic organizers, calculators, memory cards, portable tape recorders, radios, backup power supplies, motors, lighting equipment, toys, game devices, clocks, strobe lights, cameras, and other electrical equipment. Of these, vehicles and electrical equipment are particularly preferred.

[0130] Examples of the mobile body include a standard automobile, a large special-purpose automobile, a small special-purpose automobile, a truck, a large motorcycle, and a standard motorcycle. [Example]

[0131] Examples of the present invention will be described below, but the present invention is not limited to these examples in any way.

[0132] (Preparation of Polymerizable Liquid Compositions 1 to 44) Liquid compositions 1 to 44 were obtained by adding a polymerizable compound, a solvent, and a photopolymerization initiator (1-benzoylcyclohexanol, manufactured by Tokyo Chemical Industry Co., Ltd.) as shown in Tables 1 to 3. The amount of the photopolymerizable compound added was 1% by mass based on the total amount of the polymerizable compounds.

[0133] [Table 1]

[0134] [Table 2]

[0135] [Table 3]

[0136] Details of each material listed in Tables 1 to 3 are as follows. PEG200DA (PEG200 diacrylate, manufactured by Daicel Allnex Co., Ltd.) A400 (Polyethylene glycol diacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd.) #230D (Viscoat #230D, 1,6-hexanediol acrylic acid polymer ester, manufactured by Osaka Organic Chemical Industry Ltd.) HX220D (KAYARAD HX220D, 6-(propenoyloxy)hexanoic acid 3-[2,2-dimethyl-3-[[1-oxo-6-(propenoyloxy)hexyl]oxy]propoxy]-2,2-dimethyl-3-oxopropyl, manufactured by Nippon Kayaku Co., Ltd.) HX620D (KAYARAD HX620D, poly[oxy(1-oxo-1,6-hexanediyl)], α-hydro-w-[(1-oxo-2-propenyl)oxy]-, diester with 3-hydroxy-2,2-dimethylpropyl 3-hydroxy-2,2-dimethylpropanoate (9CI), manufactured by Nippon Kayaku Co., Ltd.) CN2283NS (polyester acrylate, manufactured by Sartomer) CN2273NS (polyester acrylate, manufactured by Sartomer) M6100 (polyester acrylate, manufactured by Toagosei Co., Ltd.) M6500 (polyester acrylate, manufactured by Toagosei Co., Ltd.) HPP-A (Light Acrylate HPP-A, hydroxypivalic acid neopentyl glycol acrylic acid adduct, manufactured by Kyoeisha Chemical Co., Ltd.) APG-400 (Polypropylene glycol diacrylate, manufactured by Shin-Nakamura Chemical Co., Ltd.) M321 (trimethylolpropane PO modified triacrylate, manufactured by Toagosei Co., Ltd.) CN2270NS (polyester acrylate, manufactured by Sartomer)

[0137] Example 1 <Formation of elastic layer on negative electrode substrate> A SUS foil (average thickness 10 μm) was used as the negative electrode substrate, and lithium (average thickness 20 μm) was attached to one side of the negative electrode substrate as a negative electrode layer. Next, Liquid Composition 1 was filled into an inkjet ejection device equipped with a GEN5 head (manufactured by Ricoh Printing Systems Co., Ltd.). The negative electrode substrate was placed on a stage with the side without lithium facing up, and the liquid composition was applied by inkjet. Immediately thereafter, the applied area was irradiated with UV light (light source: UV-LED (trade name: FJ800, manufactured by Phoseon), wavelength: 365 nm, irradiation intensity: 30 mW / cm) in a nitrogen atmosphere. 2 The cured product was then heated at 120°C for 5 minutes using a hot plate to remove the solvent, forming an elastic layer on the negative electrode substrate. The elastic layer measured 120mm x 120mm, and had an average film thickness of 50µm at 25°C.

[0138] -Evaluation of the elastic layer- The porosity of the elastic layer of Example 1 was measured by cross-sectional SEM observation and image processing, and was found to be 40%. Furthermore, the elastic layer of Example 1 was pressed at 500 MPa at 25°C for 5 minutes, and then released from the press for 5 minutes. The average thickness of the elastic layer was 49.4 μm, and the elastic modulus [%] = average film thickness after pressing [μm] / average film thickness before pressing [μm] was 98.8%. Therefore, the elastic layer of Example 1 is a layer that has elastic behavior, and even when pressed at a high pressure of 500 MPa, it recovers to a film thickness equal to or greater than the film thickness at the time of compression after release from the press.

[0139] <Preparation of positive electrode> -Preparation of positive electrode active material- The positive electrode active material used was a nickel-based positive electrode active material (NCM, manufactured by Toshima Manufacturing Co., Ltd.). LiNbO3 was used as the ion-conductive oxide that coated the surface of the NCM particles. The LiNbO3 coating layer was formed by hydrolyzing an alkoxide solution containing lithium and niobium on the surface of the NCM powder particles, based on Electrochemistry Communications 9 (2007) 1486-1490. Specifically, the process is as follows. First, metallic lithium (manufactured by Honjo Metals Co., Ltd.) was dissolved in absolute ethanol (manufactured by Kanto Chemical Co., Inc.) to prepare an ethanol solution of lithium ethoxide. Niobium pentaethoxide (Nb(OC2H5)5) (manufactured by Kojundo Chemical Laboratory Co., Ltd.) was added to this solution to create an alkoxide solution containing lithium and niobium. NCM powder was fluidized using a tumbling fluidizer, and the alkoxide solution was sprayed onto it to obtain a precursor powder in which the surfaces of the NCM powder particles were coated with alkoxide. This precursor powder was heated at 350°C in a dry air atmosphere to synthesize LNO / NCM, which had a LiNbO3 layer formed on the surface of the NCM1.

[0140] -Preparation of positive electrode coating liquid- A positive electrode coating solution was prepared by dispersing 45.3 mass% of LNO / NCM as the positive electrode active material, 2.2 mass% of acetylene black (manufactured by DENKA Corporation) as a conductive additive for the positive electrode composite layer, 1.4 mass% of polybutyl methacrylate (PBMA, manufactured by Aldrich Chemical Company) as a binder for the positive electrode composite layer, and 14.7 mass% of the argyrodite-type sulfide solid electrolyte Li6PS5Cl (LPSC) as a solid electrolyte for the positive electrode composite layer in 36.4 mass% of anisole (manufactured by Tokyo Chemical Industry Co., Ltd.). The argyrodite-type sulfide solid electrolyte Li6PS5Cl (LPSC) used as the solid electrolyte for the positive electrode composite layer was synthesized based on the synthesis method described in J. Power Sources. 2018, 396, 33-40. Specifically, the synthesis method is as follows. 0.5 g of Li2S (99.9%, Mitsuwa Chemical Co., Ltd.), 0.5 g of PS2S5 (99%, Sigma-Aldrich), and 0.5 g of LiCl (99%, Sigma-Aldrich) were milled for 40 hours in a planetary ball mill (PULVERISETTE, Fritsch, Germany) to obtain the argyrodite-type sulfide solid electrolyte Li6PS5Cl (LPSC). The milling was carried out in a 45 mL zirconia pot using 15 zirconia balls (diameter: 10 mm) at 600 RPM.

[0141] -Positive electrode coating- The positive electrode coating solution was applied intermittently to one side of an aluminum foil (average thickness 12 μm) serving as a positive electrode substrate using a die coater. The solvent was then removed by heating at 80°C for 5 minutes in a drying oven, and the substrate was then pressed at 50 MPa using a roll press. A 100 mm x 100 mm specimen was then punched out using a punching machine to produce a positive electrode having a positive electrode composite layer on one side of the positive electrode substrate. The average thickness of the formed positive electrode composite layer was 80 μm, and the battery capacity per unit area was 2.86 mAh / cm. 2 It was.

[0142] <Formation of functional layer on negative electrode substrate> -Preparation of functional layer coating liquid- A coating solution for forming a functional layer with lithium dendrite suppression function was prepared by adding nano Ag particles, acetylene black, and PVDF (polyvinylidene fluoride) as a binder to an NMP solvent.

[0143] -Functional layer coating- The functional layer coating solution was intermittently applied to the surface of the negative electrode substrate where the lithium (negative electrode layer) was attached (the surface opposite the surface where the elastic layer was formed) using a die coater. The substrate was then heated in a drying oven at 80°C for 5 minutes, and then vacuum dried at 60°C for 12 hours to remove the solvent. It was then pressed at 50 MPa using a roll press. The functional layer was then formed on the negative electrode layer by punching out a 110 mm x 110 mm sample using a punching machine. The average thickness of the functional layer was 10 μm.

[0144] <Formation of solid electrolyte layer> -Preparation of solid electrolyte coating liquid- As the solid electrolyte for the solid electrolyte layer, an argyrodite-type sulfide solid electrolyte Li6PS5Cl (LPSC) synthesized in the same manner as the solid electrolyte for the positive electrode composite layer was used. The solid electrolyte coating solution was prepared by adding anisole to the argyrodite-type sulfide solid electrolyte Li6PS5Cl (LPSC) and SBS (styrene butadiene styrene).

[0145] - Fabrication of solid electrolyte layer - A sheet-shaped solid electrolyte layer was produced by die-coating a solid electrolyte coating solution onto a nonwoven fabric (manufactured by Nippon Kodoshi Kogyo Co., Ltd.) and drying it for 5 minutes at 80°C. The size of the solid electrolyte was 120mm x 120mm, and the average thickness was 35μm.

[0146] <Fabrication of all-solid-state electrochemical devices> First, a solid electrolyte layer was placed on the functional layer of the integrated elastic layer, negative electrode substrate, negative electrode layer, and functional layer, and then sealed with an aluminum laminate. Then, the solid electrolyte layer was pressed at 500 MPa for 5 minutes using cold isostatic pressing (CIP). The solid electrolyte layer was then removed from the aluminum laminate, and the positive electrode was placed on the solid electrolyte layer so that the positive electrode composite layer was in contact with the solid electrolyte layer. After sealing with an aluminum laminate, the lead wire was welded and pressed at 500 MPa for 5 minutes using cold isostatic pressing (CIP). After cold isostatic pressing (CIP), the average thickness of the positive electrode composite layer was 70 μm, the average thickness of the solid electrolyte layer was 25 μm, and the average thickness of the functional layer was 7 μm. Finally, a confining pressure of 0.5 MPa was applied to fix the solid electrolyte layer with a flat plate, and 10 all-solid-state electrochemical elements of Example 1 with a cell size of 100 mm × 100 mm were produced.

[0147] Example 2 An all-solid-state electrochemical element of Example 2 was produced in the same manner as in Example 1, except that the method for applying Liquid Composition 1 in Example 1 was changed to die coating.

[0148] Example 3 An all-solid-state electrochemical element of Example 3 was produced in the same manner as in Example 1, except that the method for applying Liquid Composition 1 in Example 1 was changed to spin coating.

[0149] Example 4 An all-solid-state electrochemical element of Example 4 was produced in the same manner as in Example 1, except that the method for applying Liquid Composition 1 in Example 1 was changed to spray coating.

[0150] (Comparative Example 1) In Example 1, the elastic layer was formed by applying Liquid Composition 1 onto the negative electrode substrate, whereas in Comparative Example 1, the elastic layer was prepared in the form of an independent sheet. Specifically, Liquid Composition 1 was filled into an inkjet ejection device equipped with a GEN5 head (manufactured by Ricoh Printing Systems Co., Ltd.). A PET release film was placed on the stage, and Liquid Composition 1 was applied by inkjet. Immediately thereafter, the applied area was irradiated with UV light (light source: UV-LED (trade name: FJ800, manufactured by Phoseon), wavelength: 365 nm, irradiation intensity: 30 mW / cm) in a nitrogen atmosphere. 2 The cured product was then heated at 120°C for 5 minutes using a hot plate to remove the solvent, and the PET release film was peeled off to produce an independent sheet-like elastic layer measuring 110 mm x 110 mm and with an average film thickness of 50 μm. The negative electrode substrate, negative electrode layer, functional layer, solid electrolyte layer, positive electrode composite layer, and positive electrode substrate were produced in the same manner as in Example 1, except that the elastic layer was in the form of an independent sheet.

[0151] First, a solid electrolyte layer was placed on the functional layer of the integrated negative electrode substrate, negative electrode layer, and functional layer, and then sealed with an aluminum laminate. Then, the solid electrolyte layer was pressed at 500 MPa for 5 minutes using a cold isostatic press (CIP). The assembly was then removed from the aluminum laminate, and the elastic layer and positive electrode were placed so that the negative electrode substrate was in contact with the elastic layer and the solid electrolyte layer was in contact with the positive electrode composite layer. After sealing with an aluminum laminate, the lead wires were welded and pressed at 500 MPa using a cold isostatic press (CIP) for 5 minutes. Finally, a confining pressure of 0.5 MPa was applied to fix the assembly with a flat plate, producing 10 all-solid-state electrochemical elements of Comparative Example 1 with a cell size of 100 mm × 100 mm.

[0152] (Comparative Example 2) An all-solid-state electrochemical element of Comparative Example 2 was produced in the same manner as in Comparative Example 1, except that the thickness of the elastic layer was set to 30 μm.

[0153] (Comparative Example 3) An all-solid-state electrochemical element of Comparative Example 3 was produced in the same manner as in Comparative Example 1, except that the thickness of the elastic layer was set to 100 μm.

[0154] Comparative Example 4 An all-solid-state electrochemical element of Comparative Example 4 was produced in the same manner as in Comparative Example 1, except that the thickness of the elastic layer was set to 200 μm.

[0155] (Comparative Example 5) An all-solid-state electrochemical element of Comparative Example 5 was produced in the same manner as in Comparative Example 1, except that the material for the elastic layer was a urethane sheet having a thickness of 50 μm.

[0156] (Comparative Example 6) An all-solid-state electrochemical element of Comparative Example 6 was produced in the same manner as in Comparative Example 1, except that the material of the elastic layer was silicone rubber with a thickness of 50 μm.

[0157] (Comparative Example 7) An elastic layer of Comparative Example 7 was produced in the same manner as in Example 1, except that Liquid Composition 43 was used instead of Liquid Composition 1.

[0158] (Comparative Example 8) An elastic layer of Comparative Example 8 was produced in the same manner as in Example 1, except that Liquid Composition 44 was used instead of Liquid Composition 1.

[0159] Table 4 shows the results of yield evaluation for Examples 1 to 4 and Comparative Examples 1 to 8.

[0160] <Yield evaluation> The cell voltage of 10 all-solid-state electrochemical devices was evaluated using a multimeter, and all-solid-state electrochemical devices with a voltage of 2.2 V or higher were rated as acceptable, and all-solid-state electrochemical devices with a voltage of less than 2.2 V were rated as unacceptable. The yield was evaluated by rating examples with eight or more acceptable all-solid-state electrochemical devices as acceptable, and examples with seven or fewer acceptable all-solid-state electrochemical devices as unacceptable. In Comparative Examples 7 and 8, the elastic layer curled severely, making it impossible to fabricate an all-solid-state electrochemical device, and these were marked with a "-".

[0161] [Table 4]

[0162] As shown in Example 1, a liquid composition containing a polymerizable compound represented by general formula (1) or (2) was applied to a negative electrode substrate by inkjet printing to form an elastic layer with a porosity of 20% or more, which resulted in the stable production of an all-solid-state electrochemical device. Furthermore, as shown in Examples 2 to 4, it was also possible to stably produce an all-solid-state electrochemical device by application not only by inkjet printing but also by die coating, spin coating, and spray coating. On the other hand, when the elastic layer was formed as an independent sheet rather than by applying a liquid composition onto the negative electrode substrate, the yield decreased and it was not possible to stably manufacture an all-solid-state electrochemical device, as shown in Comparative Examples 1 to 6. Furthermore, when the porosity of the elastic layer was less than 20%, curling of the elastic layer made it impossible to manufacture an all-solid-state electrochemical device, as shown in Comparative Examples 7 and 8.

[0163] (Examples 5 to 8) All-solid-state electrochemical elements of Examples 5 to 8 were produced in the same manner as in Example 1, except that the thickness of the elastic layer was changed to the thickness shown in Table 5.

[0164] (Examples 9 to 49) All-solid-state electrochemical devices of Examples 9 to 49 were produced in the same manner as in Example 1, except that liquid compositions shown in Tables 5 and 6 were used instead of Liquid Composition 1.

[0165] Example 50 An all-solid-state electrochemical device as shown in Figure 5 was fabricated. An all-solid-state electrochemical device of Example 50 was produced in the same manner as in Example 1, except that the device did not have the negative electrode layer and the functional layer.

[0166] Example 51 An all-solid-state electrochemical device as shown in Figure 6 was fabricated. An all-solid-state electrochemical device of Example 51 was produced in the same manner as in Example 1, except that the device did not have a functional layer.

[0167] Example 52 An all-solid-state electrochemical device as shown in Figure 7 was fabricated. An all-solid-state electrochemical device of Example 52 was produced in the same manner as in Example 1, except that the negative electrode layer was not provided.

[0168] Example 53 The all-solid-state electrochemical element of Example 53 was prepared in the same manner as in Example 51, except that the negative electrode layer (negative electrode composite layer) was formed by die coating using silicon particles, styrene-butadiene rubber (SBR), and acetylene black.

[0169] Example 54 The all-solid-state electrochemical element of Example 54 was fabricated in the same manner as in Example 51, except that the negative electrode layer (negative electrode composite layer) was formed by die coating using a mixed material of silicon particles, graphite particles, styrene-butadiene rubber (SBR), and acetylene black.

[0170] Example 55 The all-solid-state electrochemical element of Example 55 was prepared in the same manner as in Example 51, except that the negative electrode layer (negative electrode composite layer) was formed by die coating using graphite particles, styrene-butadiene rubber (SBR), and acetylene black.

[0171] Example 56 An all-solid-state electrochemical element of Example 56 was produced in the same manner as in Example 1, except that the solid electrolyte layer was formed by the die coating method without using a nonwoven fabric.

[0172] Example 57 An all-solid-state electrochemical element of Example 57 was produced in the same manner as in Example 1, except that the solid electrolyte layer was formed by an inkjet method without using a nonwoven fabric.

[0173] Example 58 The all-solid-state electrochemical element of Example 58 was produced in the same manner as in Example 1, except that in Example 1, lithium lanthanum zirconate (LLZO) was used as the material for the solid electrolyte layer and the solid electrolyte layer was formed by tape casting.

[0174] Example 59 An all-solid-state electrochemical device as shown in Figure 8 was fabricated. An all-solid-state electrochemical element of Example 59 was produced in the same manner as in Example 1, except that the elastic layer was produced on the positive electrode substrate instead of on the negative electrode substrate.

[0175] Example 60 An all-solid-state electrochemical device as shown in Figure 9 was fabricated. An all-solid-state electrochemical element of Example 60 was produced in the same manner as in Example 1, except that an elastic layer was produced not only on the negative electrode substrate but also on the positive electrode substrate.

[0176] Example 61 An all-solid-state electrochemical device as shown in Figure 10 was fabricated. <Formation of elastic layer on negative electrode substrate> Two negative electrode substrates, each made of SUS foil (average thickness 10 μm) and having lithium (average thickness 20 μm) attached to one side thereof as a negative electrode layer, were prepared as negative electrodes A and B, respectively. Next, Liquid Composition 1 was filled into an inkjet ejection device equipped with a GEN5 head (manufactured by Ricoh Printing Systems Co., Ltd.). Negative electrode A was placed on a stage with the surface of the negative electrode substrate on which lithium was not attached facing up, and the liquid composition was applied by inkjet. Immediately thereafter, the applied area was irradiated with UV light (light source: UV-LED (trade name: FJ800, manufactured by Phoseon), wavelength: 365 nm, irradiation intensity: 30 mW / cm) in a nitrogen atmosphere. 2 The cured product was then heated at 120°C for 5 minutes using a hot plate to remove the solvent, and an elastic layer was formed on the negative electrode substrate of negative electrode A. The size of the elastic layer thus produced was 120mm x 120mm, and the average film thickness was 50µm.

[0177] -Evaluation of the elastic layer- The results were the same as in Example 1.

[0178] <Preparation of positive electrode> -Preparation of positive electrode active material- It was prepared in the same manner as in Example 1.

[0179] -Preparation of positive electrode coating liquid- It was prepared in the same manner as in Example 1.

[0180] -Positive electrode coating- The positive electrode coating solution was applied intermittently to both sides of an aluminum foil (average thickness 12 μm) serving as a positive electrode substrate using a die coater. The solvent was then removed by heating at 80°C for 5 minutes in a drying oven, and the substrate was then pressed at 50 MPa using a roll press. A 100 mm x 100 mm sample was then punched out using a punching machine to produce a positive electrode having a positive electrode composite layer on both sides of the positive electrode substrate. The average thickness of the formed positive electrode composite layer was 80 μm, and the battery capacity per unit area was 2.86 mAh / cm. 2 It was.

[0181] <Formation of functional layer on negative electrode substrate> -Preparation of functional layer coating liquid- It was prepared in the same manner as in Example 1.

[0182] -Functional layer coating- The functional layer coating solution was intermittently applied to the surface of the negative electrode substrate (negative electrode layer) of negative electrode A and negative electrode B (the surface opposite the surface on which the elastic layer was formed) using a die coater. The substrate was then heated at 80°C for 5 minutes in a drying oven and vacuum dried at 60°C for 12 hours to remove the solvent. The substrate was then pressed at 50 MPa using a roll press. A functional layer was then formed on the negative electrode layer of each of negative electrodes A and B by punching out a 110 mm x 110 mm sample using a punching machine. The average thickness of the functional layer was 10 μm.

[0183] <Formation of solid electrolyte layer> -Preparation of solid electrolyte coating liquid- It was prepared in the same manner as in Example 1.

[0184] - Fabrication of solid electrolyte layer - Two sheet-shaped solid electrolyte layers were fabricated by die-coating a solid electrolyte coating solution onto a nonwoven fabric (manufactured by Nippon Kodoshi Kogyo Co., Ltd.) and drying it at 80°C for 5 minutes. The size of the solid electrolyte was 120mm x 120mm, and the average thickness was 35μm.

[0185] <Fabrication of all-solid-state electrochemical devices> A solid electrolyte layer was placed on each functional layer on negative electrode A and negative electrode B, sealed with an aluminum laminate, and then pressurized at 500 MPa for 5 minutes using cold isostatic pressing (CIP). The resulting solid electrolyte layers were then removed from the aluminum laminate, and a positive electrode was placed on each solid electrolyte layer so that the positive electrode composite layer was in contact with the solid electrolyte layer. The resulting solid electrolyte layers were sealed with an aluminum laminate, and then a lead wire was welded to form a unit cell. One unit cell was stacked and pressurized at 500 MPa for 5 minutes using cold isostatic pressing (CIP). After cold isostatic pressing (CIP), the average thickness of the positive electrode composite layer was 70 μm, the average thickness of the solid electrolyte layer was 25 μm, and the average thickness of the functional layer was 7 μm. Finally, a confining pressure of 0.5 MPa was applied to fix the cells with a flat plate, producing 10 all-solid-state electrochemical elements of Example 60 with a cell size of 100 mm × 100 mm.

[0186] (Examples 61 to 64) All-solid-state electrochemical devices of Examples 61 to 64 were produced in the same manner as in Example 60, except that the number of layers was set to the number shown in Table 8. The results of Examples 55 to 59 are shown in Table 6.

[0187] In Examples 1 to 64, the results of cell evaluation are shown in Tables 5 to 8.

[0188] <Cycle characteristics> A charge / discharge cycle test was performed using a charge / discharge tester (Toyo Systems, TOSCAT-3100) at a voltage range of 4.3V to 3.0V (in a constant temperature bath at 25°C). The charge rate and discharge rate were both 0.2C, and the average voltage and discharge capacity retention rate after 100 cycles were evaluated. A discharge capacity retention rate after 100 cycles of 80% or more was evaluated as ◯, less than 80% and 70% or more was evaluated as △, and less than 70% was evaluated as ×. A rating of △ or higher was considered a pass.

[0189] <Energy density> The energy density per volume was calculated from the thickness of each layer (elastic layer, anode substrate, anode layer, functional layer, solid electrolyte layer, cathode composite layer, cathode substrate), battery capacity (battery capacity per unit area x cell area), and average voltage. Energy densities of 600 Wh / L or more were rated as ◯, those less than 600 Wh / L and 400 Wh / L or more were △, and those less than 400 Wh / L were ×. A △ or higher was considered a pass.

[0190] [Table 5]

[0191] [Table 6]

[0192] [Table 7]

[0193] [Table 8]

[0194] As shown in Examples 1 to 64, it is clear that when an elastic layer having a porous structure with a porosity of 20% or more is included, an all-solid-state electrochemical element can be obtained that is large, has a high energy density, and has an elastic layer that can absorb fluctuations in cell thickness during charge and discharge.

[0195] The embodiments of the present invention are as follows, for example. <1> a negative electrode having a negative electrode substrate; a positive electrode having a positive electrode substrate; a solid electrolyte layer provided between the negative electrode and the positive electrode, A method for producing an all-solid-state electrochemical element further comprising an elastic layer on a surface of the negative electrode substrate and / or the positive electrode substrate opposite to a surface on which the solid electrolyte layer is present, an elastic layer forming step of forming the elastic layer, The elastic layer forming step includes a coating step of coating a liquid composition containing a polymerizable compound and a solvent onto the negative electrode substrate and / or the positive electrode substrate; a polymerization step of polymerizing the polymerizable compound, The method for producing an all-solid-state electrochemical element is characterized in that the elastic layer has a porous structure with a porosity of 20% or more. <2> The polymerizable compound is a compound represented by the following general formula (1) or (2): <1> 1. A method for producing the all-solid-state electrochemical device according to claim 1. [ka] (In the general formula (1), R1 represents a hydrogen atom or a methyl group, and R2 represents any one selected from a polyester chain, a polyalkylene oxide chain, an alkyl chain, and an acrylic polymer ester derivative.) [ka] (In the general formula (2), R3 and R4 represent a hydrogen atom or a methyl group.) <3> The thickness of the elastic layer is 200 μm or less. <1> from <2> 10. The method for producing the all-solid-state electrochemical device according to claim 9, wherein the all-solid-state electrochemical device is a <4> At least one of a functional layer and an anode layer is further provided between the anode substrate and the solid electrolyte layer. <1> from <3> 10. The method for producing the all-solid-state electrochemical device according to claim 9, wherein the all-solid-state electrochemical device is a <5> The elastic layer has an elastic modulus of 80% or more, as defined by the following formula (2) using the film thickness of the elastic layer at 25°C before pressing (film thickness before pressing) and the film thickness of the elastic layer after pressing the elastic layer at 25°C at 500 MPa for 5 minutes and then releasing the press for 5 minutes (film thickness after pressing): <1> from <4> The present invention relates to a method for producing an all-solid-state electrochemical device according to any one of the above.

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[0196] 6 Liquid composition 11 Elastic layer 12 Negative electrode substrate 13 Negative electrode layer 14 Functional Layer 15 Solid electrolyte layer 17 Positive electrode substrate 18 negative electrode 19 Positive electrode 20a~g All-solid-state electrochemical devices [Prior art documents] [Patent documents]

[0197] [Patent Document 1] Patent Publication No. 2021-002495 [Patent Document 2] Japanese Patent Publication No. 2023-106356

Claims

1. a negative electrode having a negative electrode substrate; a positive electrode having a positive electrode substrate; a solid electrolyte layer provided between the negative electrode and the positive electrode, A method for producing an all-solid-state electrochemical element, further comprising the step of: providing an elastic layer on a surface of the negative electrode substrate and / or the positive electrode substrate opposite to a surface on which the solid electrolyte layer is present; an elastic layer forming step of forming the elastic layer, The elastic layer forming step includes a coating step of coating the negative electrode substrate and / or the positive electrode substrate with a liquid composition containing a polymerizable compound and a solvent; a polymerization step of polymerizing the polymerizable compound, The method for producing an all-solid-state electrochemical element, wherein the elastic layer has a porous structure with a porosity of 20% or more.

2. 2. The method for producing an all-solid-state electrochemical device according to claim 1, wherein the polymerizable compound is a compound represented by the following general formula (1) or (2): 【Chemical 1】 (In the general formula (1), R1 represents a hydrogen atom or a methyl group, and R2 represents any one selected from a polyester chain, a polyalkylene oxide chain, an alkyl chain, and an acrylic polymer ester derivative.) 【Chemistry 2】 (In the general formula (2), R3 and R4 represent a hydrogen atom or a methyl group.)

3. 2. The method for producing an all-solid-state electrochemical device according to claim 1, wherein the elastic layer has a thickness of 200 μm or less.

4. 2. The method for producing an all-solid-state electrochemical element according to claim 1, further comprising providing at least one of a functional layer and an anode layer between the anode substrate and the solid electrolyte layer.

5. 2. The method for producing an all-solid-state electrochemical element according to claim 1, wherein the elastic layer has an elastic modulus of 80% or more as defined by the following formula (2), where the thickness of the elastic layer at 25°C before pressing (pre-pressing thickness) and the thickness of the elastic layer after continuously pressing the elastic layer at 25°C at 500 MPa for 5 minutes and then releasing the pressure for 5 minutes (post-pressing thickness): [Equation 1]

6. 2. The method for producing an all-solid-state electrochemical device according to claim 1, wherein the coating step is carried out by any one of an ink-jet method, a die coating method, a spin coating method, and a spray coating method.

7. the solvent is a mixed solvent containing a good solvent in which the polymerizable compound is soluble and a poor solvent in which the polymerizable compound is insoluble, 2. The method for producing an all-solid-state electrochemical device according to claim 1, wherein the solvent satisfies the following formula (1): [Equation 2] (The mixing ratio X in the formula (1) is the content ratio of the good solvent in the mixed solvent expressed as a percentage based on the mass of the good solvent, and the solubility point of the polymerizable compound is the minimum content ratio of the good solvent in the mixed solvent in which the polymerizable compound is soluble expressed as a percentage based on the mass of the good solvent.)

8. a negative electrode having a negative electrode substrate; a positive electrode having a positive electrode substrate; a solid electrolyte layer provided between the negative electrode and the positive electrode, The negative electrode substrate and / or the positive electrode substrate further include an elastic layer on a surface opposite to the surface on which the solid electrolyte layer is present, The all-solid-state electrochemical element is characterized in that the elastic layer has a porous structure with a porosity of 20% or more.

9. 9. The all-solid-state electrochemical device according to claim 8, wherein the elastic layer contains a structural unit represented by the following general formula (3) or (4): 【Chemistry 3】 (In the general formula (3), R6 represents a hydrogen atom or a methyl group, and R7 represents any one selected from a polyester chain, a polyalkylene oxide chain, an alkyl chain, and an acrylic polymer ester derivative.) 【Chemistry 4】 (In the general formula (4), R8 and R9 represent a hydrogen atom or a methyl group.)

10. 9. The all-solid-state electrochemical device according to claim 8, wherein the elastic layer has a thickness of 200 μm or less.

11. 9. The all-solid-state electrochemical element according to claim 8, further comprising at least one of a functional layer and an anode layer between the anode substrate and the solid electrolyte layer.

12. 9. The all-solid-state electrochemical element according to claim 8, wherein the elastic layer has an elastic modulus of 80% or more as defined by the following formula (2), using the film thickness of the elastic layer at 25°C before pressing (film thickness before pressing) and the film thickness of the elastic layer after continuously pressing the elastic layer at 25°C at 500 MPa for 5 minutes and then releasing the press for 5 minutes (film thickness after pressing): [Equation 3]

13. The all-solid-state electrochemical device according to any one of claims 8 to 12, which is an all-solid-state battery.

14. An electrical device comprising the all-solid-state electrochemical device according to claim 13.

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