Exterior material for all-solid-state batteries and all-solid-state batteries using the same

Abstract

To provide a sheath material for an all-solid battery capable of achieving both excellent heat seal strength and excellent hydrogen sulfide absorptivity.SOLUTION: A sheath material for an all-solid battery at least comprises a base material layer, a gas barrier layer, a sealant layer, and a hydrogen sulfide adsorption layer. The hydrogen sulfide adsorption layer contains a modified polyolefin resin and a hydrogen sulfide adsorbent, having a thickness equal to or more than 0.5 μm and less than 10 μm.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to an outer casing material for all-solid-state batteries and an all-solid-state battery using the same. [Background technology]

[0002] Rechargeable batteries such as lithium-ion batteries are widely used in portable electronic devices, electric vehicles, and hybrid electric vehicles that use electricity as a power source. As a battery that enhances the safety of lithium-ion batteries, all-solid-state lithium batteries, which use inorganic solid electrolytes instead of organic solvent electrolytes, are being considered. All-solid-state lithium batteries are safer than lithium-ion batteries in that they are less prone to thermal runaway due to short circuits, etc.

[0003] Among inorganic solid electrolytes, sulfide-based solid electrolytes have higher ionic conductivity compared to oxide-based solid electrolytes and offer many advantages in obtaining higher-performance all-solid-state batteries. For example, Patent Document 1 discloses an all-solid-state battery using a sulfide-based electrolyte powder containing sulfur, lithium, and at least one element selected from the group consisting of boron, silicon, germanium, phosphorus, and aluminum, with an average particle size of 0.01 to 10 μm. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2008-288098 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, all-solid-state batteries using sulfide-based solid electrolytes may generate toxic hydrogen sulfide (H2S) due to moisture entering the battery. Therefore, it is necessary to quickly remove the hydrogen sulfide generated from the sulfide-based solid electrolyte, especially on the inside of the casing (the side with the sulfide-based solid electrolyte). In addition to hydrogen sulfide absorption, the casing material must also have excellent heat seal strength from the perspective of sealing the all-solid-state battery package.

[0006] This disclosure has been made in view of the problems of the prior art described above, and aims to provide an exterior material for all-solid-state batteries that can achieve both excellent heat seal strength and excellent hydrogen sulfide absorption, and an all-solid-state battery using the same. [Means for solving the problem]

[0007] To achieve the above objective, this disclosure provides an exterior material for an all-solid-state battery comprising at least a base layer, a gas barrier layer, a sealant layer, and a hydrogen sulfide adsorption layer, wherein the hydrogen sulfide adsorption layer comprises a modified polyolefin resin and a hydrogen sulfide adsorbent, and has a thickness of 0.5 μm or more and less than 10 μm.

[0008] In the above-described exterior material for all-solid-state batteries, the hydrogen sulfide adsorption layer may be located on the surface of the sealant layer opposite to the gas barrier layer.

[0009] In the above-described exterior material for all-solid-state batteries, the hydrogen sulfide adsorption layer may be located on the gas barrier layer side of the sealant layer.

[0010] In the above-mentioned exterior material for all-solid-state batteries, the modified polyolefin resin may be an acid-modified polyolefin resin.

[0011] The above-mentioned acid-modified polyolefin resin may also be a maleic anhydride-modified polypropylene resin.

[0012] The acid value of the above acid-modified polyolefin resin may be 2 to 30 mg KOH / g.

[0013] The melting point of the acid-modified polyolefin resin may be 70 to 150 °C.

[0014] In the above-mentioned exterior material for all-solid-state batteries, the content of the hydrogen sulfide adsorbent may be 1 to 50% by mass based on the total amount of the hydrogen sulfide adsorption layer.

[0015] In the above-mentioned exterior material for all-solid-state batteries, the hydrogen sulfide adsorption layer may further contain at least one selected from the group consisting of isocyanate compounds, carbodiimide compounds, and oxazoline compounds.

[0016] In the above-mentioned exterior material for all-solid-state batteries, the hydrogen sulfide adsorption layer may be formed by coating a coating liquid containing at least a modified polyolefin resin and a hydrogen sulfide adsorbent.

[0017] In the above-mentioned exterior material for all-solid-state batteries, the thickness of the hydrogen sulfide adsorption layer may be less than 5 μm.

[0018] The present disclosure also provides an all-solid-state battery including a battery element containing a sulfide-based solid electrolyte, a current extraction terminal extending from the battery element, and the exterior material for all-solid-state batteries according to any one of claims 1 to 10 that sandwiches the current extraction terminal and houses the battery element.

Advantages of the Invention

[0019] According to the present disclosure, it is possible to provide an exterior material for all-solid-state batteries that can achieve both excellent heat seal strength and excellent hydrogen sulfide absorption, and an all-solid-state battery using the same.

Brief Description of the Drawings

[0020] [Figure 1] It is a schematic cross-sectional view of an exterior material for all-solid-state batteries according to an embodiment of the present disclosure. [Figure 2] It is a schematic cross-sectional view of an exterior material for all-solid-state batteries according to an embodiment of the present disclosure. [Figure 3]This is a schematic cross-sectional view of an exterior material for an all-solid-state battery according to an embodiment of the present disclosure. [Figure 4] This is a schematic cross-sectional view of an exterior material for an all-solid-state battery according to an embodiment of the present disclosure. [Figure 5] This is a perspective view of an all-solid-state battery according to an embodiment of the present disclosure. [Figure 6] This is a schematic diagram for explaining a method of manufacturing a sample for measuring heat seal strength in an example. [Embodiments for Carrying Out the Invention]

[0021] Hereinafter, preferred embodiments of the present disclosure will be described in detail with appropriate reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant descriptions are omitted. Also, the dimensional ratios in the drawings are not limited to the illustrated ratios.

[0022] [Exterior Material for All-Solid-State Battery] FIG. 1 is a cross-sectional view schematically showing an embodiment of an exterior material for an all-solid-state battery of the present disclosure. As shown in FIG. 1, the exterior material (exterior material for an all-solid-state battery) 10 of the present embodiment includes a base material layer 11, a first adhesive layer 12a provided on one surface side of the base material layer 11, a gas barrier layer 13 provided on the side opposite to the base material layer 11 of the first adhesive layer 12a and having first and second corrosion prevention treatment layers 14a and 14b on both surfaces, a second adhesive layer 12b provided on the side opposite to the first adhesive layer 12a of the gas barrier layer 13, a sealant layer 16 provided on the side opposite to the gas barrier layer 13 of the second adhesive layer 12b, and a hydrogen sulfide adsorption layer 18 provided on the side opposite to the gas barrier layer 13 of the sealant layer 16, which are laminated. Here, the first corrosion prevention treatment layer 14a is provided on the surface of the gas barrier layer 13 on the side of the base material layer 11, and the second corrosion prevention treatment layer 14b is provided on the surface of the gas barrier layer 13 on the side of the sealant layer 16. In the exterior material 10, the base material layer 11 is the outermost layer and the hydrogen sulfide adsorption layer 18 is the innermost layer. That is, the exterior material 10 is used with the base material layer 11 facing the outside of the all-solid-state battery and the hydrogen sulfide adsorption layer 18 facing the inside of the all-solid-state battery. Hereinafter, each layer constituting the exterior material 10 will be specifically described.

[0023] <Base material layer 11> The base layer 11 provides heat resistance during the sealing process when manufacturing solid-state batteries and plays a role in suppressing the occurrence of pinholes that may occur during molding and distribution. In particular, for exterior materials of large-scale solid-state batteries, it can also provide scratch resistance, chemical resistance, and insulation.

[0024] The base layer 11 is preferably a layer formed of an insulating resin. Suitable resins include polyester resin, polyamide resin, polyimide resin, polyamide-imide resin, polyetherketone resin, polyphenylene sulfide resin, polyetherimide resin, polysulfone resin, fluororesin, phenolic resin, melamine resin, urethane resin, allyl resin, silicone resin, epoxy resin, furan resin, acetylcellulose resin, and the like.

[0025] When applied to the base layer 11, these resins may be in the form of stretched or unstretched films, or in the form of a coating film. Furthermore, the base layer 11 may be single-layer or multi-layer, and in the case of a multi-layer, it may be formed by combining different resins. If the base layer 11 is a film, it may be co-extruded or laminated with an adhesive. If the base layer 11 is a coating film, it may be coated multiple times, or it may be a multi-layer structure combining a film and a coating film.

[0026] Among these resins, polyester resin or polyamide resin is preferred as the base layer 11 due to its excellent moldability. Examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Examples of polyamide resins that constitute the polyamide film include nylon 6, nylon 6,6, copolymer of nylon 6 and nylon 6,6, nylon 6, nylon 9T, nylon 10, polymetaxylylene adipamide (MXD6), nylon 11, and nylon 12.

[0027] When these resins are used in film form, a biaxially oriented film is preferred. Examples of stretching methods for biaxially oriented films include sequential biaxial stretching, tubular biaxial stretching, and simultaneous biaxial stretching. From the viewpoint of obtaining better deep-drawing moldability, a biaxially oriented film is preferably stretched by tubular biaxial stretching.

[0028] The thickness of the base layer 11 is preferably 6 to 40 μm, and more preferably 10 to 30 μm. A base layer thickness of 6 μm or more tends to improve the pinhole resistance and insulation properties of the exterior material 10. If the thickness of the base layer 11 exceeds 40 μm, the total thickness of the exterior material 10 tends to increase.

[0029] The melting peak temperature of the base layer 11 is preferably higher than the melting peak temperature of the sealant layer 16, and more preferably 30°C or more higher than the melting peak temperature of the sealant layer 16, in order to suppress deformation of the base layer 11 during sealing.

[0030] <First adhesive layer 12a> The first adhesive layer 12a is a layer that adheres the substrate layer 11 and the gas barrier layer 13. Examples of materials constituting the first adhesive layer 12a include polyurethane resins obtained by reacting a bifunctional or more isocyanate compound (polyfunctional isocyanate compound) with a main component such as polyester polyol, polyether polyol, acrylic polyol, or carbonate polyol. The various polyols mentioned above can be used individually or in combination of two or more, depending on the functions and performance required of the exterior material 10. In addition, epoxy resins with a curing agent can also be used, but are not limited to these. Furthermore, various other additives and stabilizers may be added to the adhesives mentioned above, depending on the performance required of the adhesive.

[0031] The thickness of the first adhesive layer 12a is not particularly limited, but from the viewpoint of obtaining desired adhesive strength, conformability, and processability, for example, 1 to 10 μm is preferred, and 2 to 7 μm is more preferred.

[0032] <Gas barrier layer 13> The gas barrier layer 13 has water vapor barrier properties that prevent moisture from entering the interior of the all-solid-state battery. The gas barrier layer 13 may also have ductility for deep drawing. As the gas barrier layer 13, for example, various metal foils such as aluminum, stainless steel, and copper, or metal vapor-deposited films, inorganic oxide vapor-deposited films, carbon-containing inorganic oxide vapor-deposited films, or films with these vapor-deposited films can be used. As films with vapor-deposited films, for example, aluminum vapor-deposited films and inorganic oxide vapor-deposited films can be used. These can be used individually or in combination of two or more types. As the gas barrier layer 13, metal foil is preferred in terms of mass (specific gravity), moisture resistance, processability, and cost, and aluminum foil is more preferred.

[0033] As for the aluminum foil, soft aluminum foil that has undergone annealing treatment is particularly preferred because it can provide the desired ductility during molding. However, it is even more preferable to use aluminum foil containing iron in order to provide further pinhole resistance and ductility during molding. The iron content in the aluminum foil is preferably 0.1 to 9.0% by mass, and more preferably 0.5 to 2.0% by mass, of 100% by mass of aluminum foil. By having an iron content of 0.1% by mass or more, an exterior material 10 with better pinhole resistance and ductility can be obtained. By having an iron content of 9.0% by mass or less, an exterior material 10 with better flexibility can be obtained. As for the aluminum foil, untreated aluminum foil may be used, but it is preferable to use degreased aluminum foil in order to provide corrosion resistance. When degreasing the aluminum foil, the degreasing treatment may be applied to only one side of the aluminum foil, or to both sides.

[0034] The thickness of the gas barrier layer 13 is not particularly limited, but is preferably 9 to 200 μm, and more preferably 15 to 100 μm, considering barrier properties, pinhole resistance, and processability.

[0035] <First and second corrosion-preventive treatment layers 14a, 14b> The first and second corrosion-preventive treatment layers 14a and 14b are layers provided on the surface of the gas barrier layer 13 to prevent corrosion of the metal foil (metal foil layer) and other materials constituting the gas barrier layer 13. The first corrosion-preventive treatment layer 14a also plays a role in increasing the adhesion between the gas barrier layer 13 and the first adhesive layer 12a. The second corrosion-preventive treatment layer 14b also plays a role in increasing the adhesion between the gas barrier layer 13 and the second adhesive layer 12b. The first corrosion-preventive treatment layer 14a and the second corrosion-preventive treatment layer 14b may be layers with the same composition or layers with different compositions. The first and second corrosion-preventive treatment layers 14a and 14b (hereinafter also simply referred to as "corrosion-preventive treatment layers 14a and 14b") may be formed by, for example, degreasing, hot water modification, anodizing, chemical conversion, or a combination thereof.

[0036] Degreasing treatments include acid degreasing and alkaline degreasing. Acid degreasing methods include using inorganic acids such as sulfuric acid, nitric acid, hydrochloric acid, and hydrofluoric acid individually, or mixtures thereof. Furthermore, as an acid degreasing method, using an acid degreasing agent obtained by dissolving a fluorine-containing compound such as monosodium ammonium difluoride in the above inorganic acid not only provides a degreasing effect on aluminum, especially when aluminum foil is used in the gas barrier layer 13, but also allows the formation of a passive aluminum fluoride, which is effective in terms of corrosion resistance. Alkaline degreasing methods include using sodium hydroxide, etc.

[0037] Examples of hydrothermal alteration treatments include the boehmite treatment, which involves immersing aluminum foil in boiling water to which triethanolamine has been added. Examples of anodizing treatments include the anodizing treatment.

[0038] Chemical treatments can be immersion-type or coating-type. Immersion-type chemical treatments include, for example, chromate treatment, zirconium treatment, titanium treatment, vanadium treatment, molybdenum treatment, calcium phosphate treatment, strontium hydroxide treatment, cerium treatment, ruthenium treatment, or various chemical treatments consisting of mixed phases thereof. On the other hand, a coating-type chemical treatment is a method of applying a coating agent having corrosion-preventive properties onto the gas barrier layer 13.

[0039] When forming at least a portion of the corrosion-preventive treatment layer using one of these corrosion-preventive treatments—hot water modification, anodic oxidation, or chemical conversion—it is preferable to perform the degreasing treatment described above beforehand. Furthermore, if a degreased metal foil, such as one that has undergone an annealing process, is used as the gas barrier layer 13, it is not necessary to perform the degreasing treatment again when forming the corrosion-preventive treatment layers 14a and 14b.

[0040] The coating agent used in the coating-type chemical conversion treatment preferably contains trivalent chromium. The coating agent may also contain at least one polymer selected from the group consisting of cationic polymers and anionic polymers, as described later.

[0041] In particular, in the hydrothermal modification and anodizing processes described above, the treatment agent dissolves the surface of the aluminum foil, forming aluminum compounds (boehmite, anodized aluminum) with excellent corrosion resistance. As a result, a co-continuous structure is formed from the gas barrier layer 13 using aluminum foil to the corrosion-preventive treatment layers 14a and 14b, and therefore the above processes are included in the definition of chemical conversion treatment. On the other hand, as will be described later, it is also possible to form the corrosion-preventive treatment layers 14a and 14b using only a pure coating method, which is not included in the definition of chemical conversion treatment. One example of this method is to use a sol of a rare earth element oxide, such as cerium oxide, with an average particle size of 100 nm or less, as it has an aluminum corrosion-preventive effect (inhibitor effect) and is also environmentally suitable. By using this method, it is possible to impart a corrosion-preventive effect to metal foils such as aluminum foil even with a general coating method.

[0042] Examples of sols for rare earth element oxides include sols using various solvents such as aqueous, alcoholic, hydrocarbon, ketone, ester, and ether-based solvents. Aqueous sols are preferred for rare earth element oxides.

[0043] In rare earth element oxide sols, inorganic acids such as nitric acid, hydrochloric acid, and phosphoric acid, or their salts, and organic acids such as acetic acid, malic acid, ascorbic acid, and lactic acid are usually used as dispersion stabilizers to stabilize their dispersion. Of these dispersion stabilizers, phosphoric acid in particular is expected to provide the following benefits in the exterior material 10: (1) stabilization of sol dispersion, (2) improved adhesion with the gas barrier layer 13 by utilizing the aluminum chelating ability of phosphoric acid, (3) imparting corrosion resistance by capturing aluminum ions (passivation), and (4) improved cohesive force of the corrosion prevention treatment layers (oxide layers) 14a and 14b due to the ease with which phosphoric acid undergoes dehydration condensation even at low temperatures.

[0044] Since the corrosion-preventive treatment layers 14a and 14b formed by rare earth element oxide sols are aggregates of inorganic particles, there is a risk that the cohesive force of the layers themselves may decrease even after the drying and curing process. Therefore, in this case, it is preferable that the corrosion-preventive treatment layers 14a and 14b are compounded with an anionic polymer or a cationic polymer to compensate for the cohesive force.

[0045] The corrosion-preventive treatment layers 14a and 14b are not limited to the layers described above. For example, they may be formed using a treatment agent that combines a resin binder (such as aminophenol) with phosphoric acid and a chromium compound, as is known with coated chromate. Using this treatment agent, a layer can be formed that possesses both corrosion-preventive function and adhesion. Furthermore, although it is necessary to consider the stability of the coating liquid, a layer can be formed that possesses both corrosion-preventive function and adhesion by using a coating agent that pre-mixes a rare earth element oxide sol with a polycationic polymer or a polyanionic polymer into a single liquefaction.

[0046] The mass per unit area of ​​the corrosion-preventive treatment layers 14a and 14b is 0.005 to 0.200 g / m², regardless of whether it is a multilayer or single-layer structure. 2 Preferably, 0.010 to 0.100 g / m 2 This is more preferable. A mass per unit area of ​​0.005 g / m² is preferable. 2 If the above conditions are met, it is easier to impart corrosion prevention functionality to the gas barrier layer 13. Also, the mass per unit area is 0.200 g / m². 2 Even beyond this limit, the corrosion prevention function does not change significantly. On the other hand, when using rare earth element oxide sols, if the coating film is thick, the heat during drying may result in insufficient curing, potentially leading to a decrease in cohesive force. The thickness of the corrosion prevention treatment layers 14a and 14b can be calculated from their specific gravity.

[0047] The corrosion-preventive treatment layers 14a and 14b may, from the viewpoint of making it easier to maintain adhesion between the sealant layer 16 and the gas barrier layer 13, for example, contain cerium oxide, 1 to 100 parts by mass of phosphoric acid or phosphate per 100 parts by mass of cerium oxide, and a cationic polymer; or they may be formed by chemical conversion treatment of the gas barrier layer 13; or they may be formed by chemical conversion treatment of the gas barrier layer 13 and also contain a cationic polymer.

[0048] <Second adhesive layer 12b> The second adhesive layer 12b is a layer that bonds the gas barrier layer 13 and the sealant layer 16. A general adhesive for bonding the gas barrier layer 13 and the sealant layer 16 can be used for the second adhesive layer 12b.

[0049] If a corrosion-preventive treatment layer 14b is provided on the gas barrier layer 13, and the second corrosion-preventive treatment layer 14b has a layer containing at least one polymer selected from the group consisting of cationic polymers and anionic polymers described above, it is preferable that the second adhesive layer 12b is a layer containing a compound that is reactive with the polymer contained in the second corrosion-preventive treatment layer 14b (hereinafter also referred to as "reactive compound").

[0050] For example, if the second corrosion-preventive treatment layer 14b contains a cationic polymer, the second adhesive layer 12b contains a compound that is reactive with the cationic polymer. If the second corrosion-preventive treatment layer 14b contains an anionic polymer, the second adhesive layer 12b contains a compound that is reactive with the anionic polymer. Furthermore, if the second corrosion-preventive treatment layer 14b contains both a cationic polymer and an anionic polymer, the second adhesive layer 12b contains a compound that is reactive with the cationic polymer and a compound that is reactive with the anionic polymer. However, the second adhesive layer 12b does not necessarily have to contain the above two types of compounds, and may contain a compound that is reactive with both the cationic polymer and the anionic polymer. Here, "reactive" means forming a covalent bond with the cationic polymer or the anionic polymer. The second adhesive layer 12b may further contain an acid-modified polyolefin resin.

[0051] Compounds that react with cationic polymers include at least one compound selected from the group consisting of polyfunctional isocyanate compounds, glycidyl compounds, compounds having a carboxyl group, and oxazoline compounds.

[0052] Examples of polyfunctional isocyanate compounds include diisocyanates such as tolylene diisocyanate, xylylene diisocyanate or its hydrogenated products, hexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate or its hydrogenated products, and isophorone diisocyanate; or polyisocyanates such as adducts obtained by reacting these isocyanates with polyhydric alcohols such as trimethylolpropane, biuret compounds obtained by reacting them with water, or trimer isocyanurates; or blocked polyisocyanates obtained by blocking these polyisocyanates with alcohols, lactams, oximes, etc.

[0053] Examples of glycidyl compounds include epoxy compounds obtained by reacting glycols such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,4-butanediol, 1,6-hexanediol, and neopentyl glycol with epichlorohydrin; epoxy compounds obtained by reacting polyhydric alcohols such as glycerin, polyglycerin, trimethylolpropane, pentaerythritol, and sorbitol with epichlorohydrin; and epoxy compounds obtained by reacting dicarboxylic acids such as phthalic acid, terephthalic acid, oxalic acid, and adipic acid with epichlorohydrin.

[0054] Examples of compounds having a carboxyl group include aliphatic carboxylic acid compounds, aromatic dicarboxylic acid compounds, and salts thereof. Poly(meth)acrylic acid and alkali (earth) metal salts of poly(meth)acrylic acid may also be used.

[0055] Examples of oxazoline compounds include low-molecular-weight compounds having two or more oxazoline units, and when polymerizable monomers such as isopropenyloxazoline are used, copolymers of acrylic monomers such as (meth)acrylic acid, alkyl (meth)acrylate esters, and hydroxyalkyl (meth)acrylate.

[0056] Among these, polyfunctional isocyanate compounds are preferred because they exhibit high reactivity with cationic polymers and readily form crosslinked structures.

[0057] Compounds that react with anionic polymers include at least one compound selected from the group consisting of glycidyl compounds and oxazoline compounds. Examples of these glycidyl compounds and oxazoline compounds include the glycidyl compounds and oxazoline compounds previously exemplified as crosslinking agents for forming a crosslinked structure of cationic polymers. Among these, glycidyl compounds are preferred because of their high reactivity with anionic polymers.

[0058] When the second adhesive layer 12b contains an acid-modified polyolefin resin, it is preferable that the reactive compound is also reactive with the acidic groups in the acid-modified polyolefin resin (i.e., forms a covalent bond with the acidic groups). This further improves adhesion to the second corrosion-preventive treatment layer 14b. In addition, the acid-modified polyolefin resin becomes a cross-linked structure, further improving the solvent resistance of the exterior material 10.

[0059] The content of the reactive compound is preferably equal to or 10 times the amount of the acidic groups in the acid-modified polyolefin resin. If the amount is equal to or greater than the amount, the reactive compound will react sufficiently with the acidic groups in the acid-modified polyolefin resin. On the other hand, if the amount exceeds 10 times the amount, the crosslinking reaction with the acid-modified polyolefin resin will be sufficiently saturated, and unreacted material will be present, raising concerns about a decrease in various performance characteristics. Therefore, for example, the content of the reactive compound is preferably 5 to 20 parts by mass (solid content ratio) per 100 parts by mass of the acid-modified polyolefin resin.

[0060] Acid-modified polyolefin resins are polyolefin resins into which acidic groups have been introduced. Examples of acidic groups include carboxyl groups, sulfonic acid groups, and acid anhydride groups, with maleic anhydride groups and (meth)acrylic acid groups being particularly preferred. As an acid-modified polyolefin resin, for example, the same type as the modified polyolefin resin used in the sealant layer 16 can be used.

[0061] The second adhesive layer 12b may contain various additives such as flame retardants, slip agents, antiblocking agents, antioxidants, light stabilizers, and tackifiers.

[0062] The second adhesive layer 12b may, from the viewpoint of suppressing a decrease in laminate strength when corrosive gases such as hydrogen sulfide or electrolytes are involved, and from the viewpoint of further suppressing a decrease in insulating properties, include, for example, an acid-modified polyolefin and at least one curing agent selected from the group consisting of polyfunctional isocyanate compounds, glycidyl compounds, compounds having a carboxyl group, oxazoline compounds, and carbodiimide compounds. Examples of carbodiimide compounds include N,N'-di-o-toluylcarbodiimide, N,N'-diphenylcarbodiimide, N,N'-di-2,6-dimethylphenylcarbodiimide, N,N'-bis(2,6-diisopropylphenyl)carbodiimide, N,N'-dioctyldecylcarbodiimide, N-triyl-N'-cyclohexylcarbodiimide, N,N'-di-2,2-di-t-butylphenylcarbodiimide, N-triyl-N'-phenylcarbodiimide, N,N'-di-p-nitrophenylcarbodiimide, N,N'-di-p-aminophenylcarbodiimide, N,N'-di-p-hydroxyphenylcarbodiimide, N,N'-di-cyclohexylcarbodiimide, and N,N'-di-p-toluylcarbodiimide.

[0063] As the adhesive for forming the second adhesive layer 12b, for example, a polyurethane-based adhesive containing a polyester polyol composed of hydrogenated dimer fatty acids and a diol, and a polyisocyanate can be used. Examples of adhesives include polyurethane resins obtained by reacting a bifunctional or more isocyanate compound with a main component such as a polyester polyol, polyether polyol, acrylic polyol, or carbonate polyol, and epoxy resins obtained by reacting an amine compound or the like with a main component having epoxy groups. From the viewpoint of heat resistance, these are preferred as adhesives.

[0064] The thickness of the second adhesive layer 12b is not particularly limited, but from the viewpoint of obtaining the desired adhesive strength and processability, it is preferably 1 to 10 μm, and more preferably 2 to 7 μm.

[0065] <Sealant layer 16> The sealant layer 16 is a layer that provides heat sealing properties to the outer material 10, and is a layer that is heat-sealed (heat-fused) during the assembly of the all-solid-state battery.

[0066] As the sealant layer 16, for example, thermoplastic resins such as polyolefin resins, polyamide resins, polyester resins, polycarbonate resins, polyphenylene ether resins, polyacetal resins, polystyrene resins, polyvinyl chloride resins, and polyvinyl acetate resins can be used. From the viewpoint of heat resistance and seal suitability, it is preferable to use one selected from the group consisting of polyolefin resins, polyamide resins, and polyester resins as the resin constituting the sealant layer 16 (hereinafter also referred to as the "base resin"). The various resins listed above may be used individually or in combination of two or more. By blending the various resins listed above and forming a polymer alloy, the seal suitability and heat resistance can be controlled. The sealant layer 16 may be directly laminated to the gas barrier layer 13 without an adhesive. In the case of directly laminating the sealant layer 16 to the gas barrier layer 13 without an adhesive, it is preferable that at least the layer in contact with the gas barrier layer 13 contains a compound modified by an acid or a compound having a glycidyl group.

[0067] Examples of polyolefin resins include low-density, medium-density, or high-density polyethylene; ethylene-α-olefin copolymers; polypropylene; block or random copolymers containing propylene as a copolymer component; and propylene-α-olefin copolymers. When the polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer.

[0068] Examples of polyester resins include polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polyethylene naphthalate (PEN) resin, polybutylene naphthalate (PBN) resin, and copolymers thereof. The polyester resin may also be obtained by copolymerizing any acid with a glycol.

[0069] The sealant layer 16 may contain a polyolefin elastomer. The polyolefin elastomer may be compatible with the base resin described above, or it may not be compatible, and it may contain both compatible polyolefin elastomers and incompatible polyolefin elastomers. Compatible means dispersed in the base resin with a dispersion phase size of 1 nm or more and less than 500 nm. Incompatible means dispersed in the base resin with a dispersion phase size of 500 nm or more and less than 20 μm.

[0070] When the base resin is a polypropylene-based resin, a compatible polyolefin elastomer is, for example, a propylene-butene-1 random copolymer, and an incompatible polyolefin elastomer is, for example, an ethylene-butene-1 random copolymer. Polyolefin elastomers can be used individually or in combination of two or more.

[0071] Furthermore, the sealant layer 16 may contain additives such as antioxidants, slip agents, flame retardants, antiblocking agents, light stabilizers, dehydrating agents, tackifiers, nucleating agents, and plasticizers to provide sealing properties, heat resistance, and other functionalities. Preferably, the content of these additives is 5 parts by mass or less when the total mass of the sealant layer 16 is 100 parts by mass.

[0072] The sealant layer 16 may contain a hydrogen sulfide adsorbent, but may not contain one from the viewpoint of easily obtaining excellent heat seal strength. The amount of hydrogen sulfide adsorbent in the sealant layer 16 may be 0 to 50% by mass, 0 to 20% by mass, or 0% by mass, based on the total amount of the sealant layer 16, from the viewpoint of easily obtaining excellent heat seal strength.

[0073] The sealant layer 16 may be a single-layer film or a multi-layer film, and the choice should be made according to the required function. If the sealant layer is a multi-layer structure, the layers may be laminated by co-extrusion or by dry lamination. If the sealant layer is a multi-layer structure, it is preferable to use the same type of resin for each layer from the viewpoint of interlayer adhesion. For example, the layer in contact with the gas barrier layer 13 may contain a modified polyolefin resin, and the other layers may consist of one or multiple layers of polyolefin resin, which may be laminated by co-extrusion.

[0074] The peak melting temperature of the sealant layer varies depending on the application, but for exterior materials for all-solid-state batteries, it is preferably between 160 and 280°C because it improves heat resistance.

[0075] The thickness of the sealant layer 16 is not particularly limited, but from the viewpoint of achieving both thinness and improved heat seal strength in high-temperature environments, it is preferably 10 to 100 μm, and more preferably 20 to 60 μm. A thickness of 10 μm or more of the sealant layer 16 provides sufficient heat seal strength, while a thickness of 100 μm or less reduces the amount of water vapor that penetrates from the edges of the exterior material. If the sealant layer 16 consists of multiple layers, the sum of the thicknesses of the multiple sealant layers 16 may be within the above range, or the thickness of each layer of the multiple sealant layers 16 may be within the above range.

[0076] <Hydrogen sulfide adsorption layer 18> The hydrogen sulfide adsorption layer 18 is a layer that adsorbs hydrogen sulfide generated from the solid electrolyte (e.g., sulfide-based solid electrolyte) of the all-solid-state battery, preventing hydrogen sulfide from leaking out of the all-solid-state battery. The hydrogen sulfide adsorption layer 18 comprises at least a modified polyolefin resin and a hydrogen sulfide adsorbent. The hydrogen sulfide adsorption layer 18 may also be a layer that provides heat sealing properties to the outer casing material 10. In the outer casing material 10 shown in Figure 1, the hydrogen sulfide adsorption layer 18 is placed on the inside during the assembly of the all-solid-state battery and heat-sealed (heat-fused) together with the sealant layer 16. The hydrogen sulfide adsorption layer 18 may be a single layer or multiple layers. The hydrogen sulfide adsorption layer 18 may be placed on the surface of the sealant layer 16 opposite to the gas barrier layer 13, as in the outer casing material 10 shown in Figure 1.

[0077] Conventional exterior materials have been designed so that the sealant layer is the outermost layer, because the presence of another layer on top of the sealant layer reduces heat-sealing performance. While it is possible to form a heat-sealable layer on top of the sealant layer by forming a layer with a coating liquid containing polyolefin resin, this would increase costs, so the formation of another layer on top of the sealant layer has not been considered until now. However, from the perspective of obtaining excellent hydrogen sulfide absorption, forming a hydrogen sulfide adsorption layer 18 on top of the sealant layer 16 is very effective. Furthermore, since the hydrogen sulfide adsorption layer 18 contains modified polyolefin resin, it is possible to provide excellent heat-sealing performance even when the hydrogen sulfide adsorption layer 18 is present on top of the sealant layer 16.

[0078] Furthermore, methods have been considered in which the sealant layer itself contains a hydrogen sulfide adsorbent. However, in that case, only the hydrogen sulfide adsorbent located near the surface on the inside of the battery in the thick sealant layer contributes to the adsorption of hydrogen sulfide, while the hydrogen sulfide adsorbent located further from the surface contributes almost nothing to the adsorption of hydrogen sulfide. In contrast, in the exterior material of this embodiment, by providing a thin hydrogen sulfide adsorbent layer on the surface as a separate layer from the sealant layer, the entire hydrogen sulfide adsorbent contained in this layer contributes to the adsorption of hydrogen sulfide, thereby efficiently obtaining excellent hydrogen sulfide absorption.

[0079] The modified polyolefin resin may be a resin in which a polyolefin resin has been graft-modified with an unsaturated carboxylic acid derivative component derived from an unsaturated carboxylic acid, an acid anhydride of an unsaturated carboxylic acid, or an ester of an unsaturated carboxylic acid, or it may be an acid-modified polyolefin resin.

[0080] Examples of polyolefin resins include low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-α-olefin copolymer, homopolypropylene, block polypropylene, random polypropylene, and propylene-α-olefin copolymer.

[0081] Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, and bicyclo[2,2,1]hept-2-ene-5,6-dicarboxylic acid.

[0082] Examples of unsaturated carboxylic acid acid anhydrides include maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, and bicyclo[2,2,1]hepto-2-ene-5,6-dicarboxylic acid anhydride.

[0083] Examples of esters of unsaturated carboxylic acids include methyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dimethyl maleate, monomethyl maleate, diethyl fumarate, dimethyl itaconate, diethyl citraconate, dimethyl tetrahydrophthalate anhydride, and dimethyl bicyclo[2,2,1]hepto-2-ene-5,6-dicarboxylate.

[0084] The acid-modified polyolefin resin may be a maleic anhydride-modified polyolefin resin modified with maleic anhydride, or a maleic anhydride-modified polypropylene resin from the viewpoint of adhesion to the sealant layer 16 and heat resistance. Suitable acid-modified polyolefin resins include "Admer" manufactured by Mitsui Chemicals, Inc., "Modic" manufactured by Mitsubishi Chemical Corporation, "Hardren" manufactured by Toyobo Co., Ltd., and "Aurolene" manufactured by Nippon Paper Industries Ltd. When the hydrogen sulfide adsorption layer 18 is formed by extrusion or the like, Admer, Modic, etc. are suitable as the acid-modified polyolefin resin, and when it is formed by coating with a coating liquid, Hardren and Aurolene are suitable as the acid-modified polyolefin resin. Since such acid-modified polyolefin resins have excellent reactivity with various metals and polymers having various functional groups, heat-sealability can be imparted to the hydrogen sulfide adsorption layer 18 by utilizing this reactivity.

[0085] The acid value of acid-modified polyolefin resin may be 2 mg KOH / g or higher, 6 mg KOH / g or higher, 10 mg KOH / g or higher, or 12 mg KOH / g or higher, from the viewpoint of improving solubility and adhesion to metals, etc. The acid value of acid-modified polyolefin resin may be 30 mg KOH / g or lower, 25 mg KOH / g or lower, 20 mg KOH / g or lower, or 17 mg KOH / g or lower, from the viewpoint of improving adhesion to resin components. The acid value of acid-modified polyolefin resin may be 2 to 30 mg KOH / g, or 10 to 20 mg KOH / g. The acid value of acid-modified polyolefin resin is measured by a method in accordance with JIS K0070.

[0086] The melting point of the acid-modified polyolefin resin may be 70°C or higher, 80°C or higher, 90°C or higher, or 95°C or higher, from the viewpoint of obtaining sufficient heat resistance. The melting point of the acid-modified polyolefin resin may be 150°C or lower, 140°C or lower, 130°C or lower, or 125°C or lower, from the viewpoint of easily obtaining excellent heat seal strength. The melting point of the acid-modified polyolefin resin may be 70 to 150°C, or 70 to 130°C.

[0087] The content of the modified polyolefin resin may be 50% by mass or more, 60% by mass or more, 70% by mass or more, or 80% by mass or more, based on the total amount of the hydrogen sulfide adsorption layer 18, from the viewpoint of easily obtaining excellent heat seal strength. The content of the modified polyolefin resin may be 99% by mass or less, 97% by mass or less, 95% by mass or less, 93% by mass or less, or 90% by mass or less, based on the total amount of the hydrogen sulfide adsorption layer 18, from the viewpoint of easily adsorbing hydrogen sulfide more efficiently.

[0088] A hydrogen sulfide adsorbent is a substance capable of adsorbing and / or decomposing hydrogen sulfide. Examples of hydrogen sulfide adsorbents include zinc oxide, amorphous metal silicates (mainly copper and zinc), zirconium tantanide element hydrates, tetravalent metal phosphates (especially copper), zeolites and mixtures of zinc ions, mixtures of zeolites, zinc oxide and copper(II) oxide, potassium permanganate, sodium permanganate, silver sulfate, silver acetate, aluminum oxide, iron hydroxide, aluminum silicate, potassium aluminum sulfate, zeolites, hydrotalcite, complex oxides (mainly zinc), activated carbon, amine compounds, ionomers, etc. Hydrogen sulfide adsorbents may contain zinc oxide (ZnO) and / or zinc ions for easier detoxification of hydrogen sulfide, cost, and handling. Hydrogen sulfide adsorbents can be used individually or in combination of two or more types.

[0089] As a hydrogen sulfide adsorbent, a deodorant that has a deodorizing effect on hydrogen sulfide may be used. Specifically, examples include "Daimshoe PE-M 3000-Z" manufactured by Dainichi Seika Kogyo Co., Ltd., the "Kesmon" series manufactured by Toagosei Co., Ltd., "Shoe Cleanse" (a mixture of zeolite and zinc oxide) manufactured by Rasa Industries Co., Ltd., and "Dashlight ZU" (a mixture of zeolite and zinc) and "Dashlight CZU" (a mixture of zeolite, copper oxide, and zinc oxide) manufactured by Shinanen Zeomic Co., Ltd.

[0090] The average particle size (D50) of the hydrogen sulfide adsorbent may be 0.01 μm or larger, 0.05 μm or larger, or 0.1 μm or larger, from the viewpoint of easily obtaining excellent hydrogen sulfide absorption. The average particle size (D50) of the hydrogen sulfide adsorbent may be 5 μm or smaller from the viewpoint of improving dispersibility, and may be 4 μm or smaller, 3 μm or smaller, or 2 μm or smaller from the viewpoint of increasing the specific surface area and improving hydrogen sulfide adsorption performance. The average particle size of the hydrogen sulfide adsorbent refers to the average particle size measured by dynamic light scattering.

[0091] The hydrogen sulfide adsorbent content may be 0.5% by mass or more, 1% by mass or more, 2% by mass or more, 3% by mass or more, or 5% by mass or more, based on the total amount of the hydrogen sulfide adsorption layer 18, from the viewpoint of easily obtaining excellent hydrogen sulfide absorption. The hydrogen sulfide adsorbent content may be 50% by mass or less, 40% by mass or less, 30% by mass or less, or 20% by mass or less, based on the total amount of the hydrogen sulfide adsorption layer 18, from the viewpoint of easily obtaining excellent heat seal strength. The hydrogen sulfide adsorbent content may be 0.5 to 50% by mass, 1 to 50% by mass, or 1 to 30% by mass, based on the total amount of the hydrogen sulfide adsorption layer 18.

[0092] The mass ratio of the hydrogen sulfide adsorbent content to the modified polyolefin resin content (hydrogen sulfide adsorbent content / modified polyolefin resin content) may be 0.005 or higher, 0.01 or higher, 0.02 or higher, or 0.5 or higher, from the viewpoint of more efficiently adsorbing hydrogen sulfide. The mass ratio of the hydrogen sulfide adsorbent content to the modified polyolefin resin content may be 1 or less, 0.7 or less, 0.5 or less, or 0.3 or less, from the viewpoint of easily obtaining excellent heat seal strength.

[0093] The hydrogen sulfide adsorption layer 18 may contain, for example, a curing agent, a dispersant (e.g., a surfactant such as a metal soap), an antioxidant, a slip agent, a flame retardant, an antiblocking agent, a light stabilizer, a dehydrating agent, a tackifier, a crystal nucleating agent, and a plasticizer to provide dispersibility, heat sealability, heat resistance, and other functions.

[0094] Examples of curing agents include isocyanate compounds, carbodiimide compounds, oxazoline compounds, and glycidyl compounds. From the viewpoint of heat resistance, the hydrogen sulfide adsorption layer 18 may further contain at least one selected from the group consisting of isocyanate compounds, carbodiimide compounds, and oxazoline compounds.

[0095] The isocyanate compound may be a polyfunctional isocyanate compound, and examples include diisocyanates such as tolylene diisocyanate, xylylene diisocyanate or its hydrogenated products, hexamethylene diisocyanate, 4,4'-diphenylmethane diisocyanate or its hydrogenated products, and isophorone diisocyanate; or polyisocyanates such as adducts obtained by reacting these isocyanates with a polyhydric alcohol such as trimethylolpropane, biuret obtained by reacting them with water, or trimer isocyanurates; or blocked polyisocyanates obtained by blocking these polyisocyanates with alcohols, lactams, oximes, etc.

[0096] Examples of carbodiimide compounds include N,N'-di-o-toluylcarbodiimide, N,N'-diphenylcarbodiimide, N,N'-di-2,6-dimethylphenylcarbodiimide, N,N'-bis(2,6-diisopropylphenyl)carbodiimide, N,N'-dioctyldecylcarbodiimide, N-triyl-N'-cyclohexylcarbodiimide, N,N'-di-2,2-di-t-butylphenylcarbodiimide, N-triyl-N'-phenylcarbodiimide, N,N'-di-p-nitrophenylcarbodiimide, N,N'-di-p-aminophenylcarbodiimide, N,N'-di-p-hydroxyphenylcarbodiimide, N,N'-di-cyclohexylcarbodiimide, and N,N'-di-p-toluylcarbodiimide.

[0097] Examples of oxazoline compounds include low-molecular-weight compounds having two or more oxazoline units, or, in the case of polymerizable monomers such as isopropenyloxazoline, copolymers of acrylic monomers such as (meth)acrylic acid, alkyl (meth)acrylate esters, and hydroxyalkyl (meth)acrylate.

[0098] The curing agent content may be 0.05 equivalents or more, 0.1 equivalents or more, or 0.2 equivalents or more relative to the functional groups of the modified polyolefin resin, from the viewpoint of excellent heat resistance and film cohesiveness. The curing agent content may be 2 equivalents or less, 1 equivalent or less, or 0.7 equivalents or less relative to the functional groups of the modified polyolefin resin, from the viewpoint of suppressing the brittleness of the hydrogen sulfide adsorption layer 18.

[0099] The thickness of the hydrogen sulfide adsorption layer 18 is 0.5 μm or more and less than 10 μm, from the viewpoint of achieving both excellent heat seal strength and excellent hydrogen sulfide absorption. The thickness of the hydrogen sulfide adsorption layer 18 may be 1 μm or more, 1.5 μm or more, 2 μm or more, or 3 μm or more, from the viewpoint of easily obtaining excellent hydrogen sulfide adsorption performance. The thickness of the hydrogen sulfide adsorption layer 18 may be 9 μm or less, 8 μm or less, 7 μm or less, 6 μm or less, 5 μm or less, less than 5 μm, 4 μm or less, or 3 μm or less, from the viewpoint of easily obtaining excellent heat seal strength. The thickness of the hydrogen sulfide adsorption layer 18 may be 1 to 9 μm, 1 μm or more and less than 5 μm, or 1 to 4 μm. If the hydrogen sulfide adsorption layer 18 consists of multiple layers, the sum of the thicknesses of the multiple hydrogen sulfide adsorption layers 18 may be within the above range, and the thickness of each layer of the multiple hydrogen sulfide adsorption layers 18 may be within the above range.

[0100] The ratio of the thickness of the hydrogen sulfide adsorption layer 18 to the thickness of the sealant layer 16 (thickness of hydrogen sulfide adsorption layer 18 / thickness of sealant layer 16) may be 0.01 or more, 0.03 or more, or 0.05 or more from the viewpoint of easily obtaining excellent hydrogen sulfide adsorption performance, and may be 0.5 or less, 0.3 or less, or 0.2 or less from the viewpoint of easily obtaining excellent heat seal strength. If the sealant layer 16 and / or hydrogen sulfide adsorption layer consists of multiple layers, the ratio of the thickness of the hydrogen sulfide adsorption layer 18 to the thickness of the sealant layer 16 is calculated using the total thickness of the multiple layers.

[0101] The hydrogen sulfide adsorption layer 18 may be formed by coating with a coating solution containing at least a modified polyolefin resin and a hydrogen sulfide adsorbent. While it is difficult to reduce the thickness of the hydrogen sulfide adsorption layer 18 to less than 10 μm using the extrusion method, forming the hydrogen sulfide adsorption layer 18 by coating with a coating solution makes it easier to achieve a thickness of less than 10 μm. The hydrogen sulfide adsorption layer can be formed by common coating methods such as direct gravure, reverse gravure, wire bar coating, and microgravure.

[0102] When the coating liquid contains a curing agent, the functional groups of the modified polyolefin resin react with the curing agent to form a hydrogen sulfide adsorption layer 18 with excellent heat seal strength and cohesive force. Furthermore, when the coating liquid contains a curing agent, aging is preferable from the viewpoint of ensuring that the curing reaction is fully completed. The aging temperature may be room temperature (25°C) to 100°C. If the aging temperature is above room temperature, the curing reaction proceeds more easily, and if it is below 100°C, crystallization of the sealant layer 16 is more easily suppressed. The aging time is preferably such that the reaction rate of the curing agent reaches 80% or more. If the reaction rate of the curing agent is 80% or more, the crosslinking effect of the curing agent is fully expressed.

[0103] Furthermore, as shown in Figure 1, since the hydrogen sulfide adsorption layer 18 is the outermost layer of the exterior material 10, the material can be manufactured in batches using the same manufacturing method as before, up to the step of forming the hydrogen sulfide adsorption layer 18. This allows for the production of only the required quantity of exterior material 10 with hydrogen sulfide adsorption performance, which is advantageous in terms of manufacturing costs.

[0104] Although preferred embodiments of the exterior material for all-solid-state batteries of this embodiment have been described in detail above, this disclosure is not limited to such specific embodiments, and various modifications and changes are possible within the scope of the gist of this disclosure as described in the claims.

[0105] For example, Figure 1 shows a case where corrosion prevention treatment layers 14a and 14b are provided on both sides of the gas barrier layer 13, but only one of the corrosion prevention treatment layers 14a and 14b may be provided, or no corrosion prevention treatment layer may be provided at all.

[0106] Figure 1 shows a case where the gas barrier layer 13 and the sealant layer 16 are laminated using a second adhesive layer 12b. However, the gas barrier layer 13 and the sealant layer 16 may also be laminated using an adhesive resin layer 15, as shown in the exterior material (exterior material for all-solid-state batteries) 20 in Figure 2. In addition, in the exterior material 20 shown in Figure 2, a second adhesive layer 12b may be provided between the gas barrier layer 13 and the adhesive resin layer 15.

[0107] <Adhesive resin layer 15> The adhesive resin layer 15 is composed of an adhesive resin composition as the main component and, if necessary, additive components. The adhesive resin composition is not particularly limited, but it is preferable that it contains a modified polyolefin resin.

[0108] The modified polyolefin resin is preferably a polyolefin resin that has been graft-modified with an unsaturated carboxylic acid, or an unsaturated carboxylic acid derivative derived from either its acid anhydride or ester.

[0109] Examples of polyolefin resins include low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-α-olefin copolymer, homopolypropylene, block polypropylene, random polypropylene, and propylene-α-olefin copolymer.

[0110] The modified polyolefin resin is preferably a polyolefin resin modified with maleic anhydride. Suitable modified polyolefin resins include, for example, "Admer" manufactured by Mitsui Chemicals, Inc., "Modic" manufactured by Mitsubishi Chemical Corporation, "Hardren" manufactured by Toyobo Co., Ltd., and "Aurolene" manufactured by Nippon Paper Industries Ltd. Such modified polyolefin resins exhibit excellent reactivity with various metals and polymers having various functional groups, and this reactivity can be used to impart adhesion to the adhesive resin layer 15. The adhesive resin layer 15 may also contain various additives as needed, such as various compatible and incompatible elastomers, flame retardants, slip agents, antiblocking agents, antioxidants, light stabilizers, and tackifiers.

[0111] The thickness of the adhesive resin layer 15 is not particularly limited, but from the viewpoint of stress relaxation and moisture permeability, it is preferable that it be the same as or less than that of the sealant layer 16.

[0112] In the exterior material 20, the total thickness of the adhesive resin layer 15 and the sealant layer 16 is preferably in the range of 5 to 100 μm, and more preferably in the range of 20 to 80 μm, from the viewpoint of achieving both thinning and improved heat seal strength in high-temperature environments.

[0113] The exterior material of this disclosure may further include a protective layer 17 disposed on the surface of the base layer 11 opposite to the gas barrier layer 13 side, as shown in the exterior material 20 in Figure 2.

[0114] <Protective layer 17> The protective layer 17 is a layer that protects the base layer 11. The same material as the first adhesive layer 12a can be used to constitute the protective layer 17. The protective layer 17 can be formed on the base layer 11 by coating or the like. The protective layer 17 may contain a hydrogen sulfide adsorbent and / or a color developer. When a color developer is contained in the protective layer 17, since the outermost layer of the exterior material 20 is the protective layer 17, in an all-solid-state battery module, if an abnormality occurs in any of the all-solid-state batteries in the module and hydrogen sulfide leaks out, it becomes easier to detect the abnormality in the module and identify the all-solid-state battery that is experiencing the abnormality.

[0115] The exterior material of this disclosure may have a hydrogen sulfide adsorption layer 18 arranged on the surface of the sealant layer 16 facing the gas barrier layer 13, as shown in Figure 3 (exterior material for all-solid-state batteries) 30. When the hydrogen sulfide adsorption layer 18 is arranged on the surface of the sealant layer 16 facing the gas barrier layer 13, the hydrogen sulfide adsorption layer 18 becomes a layer that adheres the gas barrier layer 13 and the sealant layer 16, so as shown in Figure 3, it is not necessary to provide the second adhesive layer 12b and the adhesive resin layer 15.

[0116] The exterior material of this disclosure may have a first sealant layer 16a and a second sealant layer 16b, as shown in Figure 4, exterior material (exterior material for all-solid-state batteries) 40. The first sealant layer 16a and the second sealant layer 16b may each be formed from the material constituting the sealant layer 16 described above. The thickness of the first sealant layer 16a may be 5 to 100 μm or 20 to 80 μm. The thickness of the second sealant layer 16b may be 5 to 100 μm or 20 to 80 μm.

[0117] [Manufacturing method for exterior materials] Next, an example of a manufacturing method for the exterior material 10 shown in Figure 1 will be described. Note that the manufacturing method for the exterior material 10 is not limited to the method described below.

[0118] The manufacturing method for the exterior material 10 of this embodiment includes the steps of: providing corrosion prevention treatment layers 14a and 14b on the gas barrier layer 13; bonding the base layer 11 and the gas barrier layer 13 using a first adhesive layer 12a; laminating a sealant layer 16 via a second adhesive layer 12b; and laminating a hydrogen sulfide adsorption layer on the sealant layer 16 to produce a laminate. The manufacturing method for the exterior material 10 may optionally include a step of aging the obtained laminate.

[0119] (Lamination process of corrosion-preventive treatment layers 14a and 14b onto the gas barrier layer 13) This process involves forming corrosion-preventive treatment layers 14a and 14b on the gas barrier layer 13. As described above, methods for this include degreasing, hot water modification, anodizing, chemical conversion, or applying a coating agent with corrosion-preventive properties to the gas barrier layer 13.

[0120] If the corrosion prevention treatment layers 14a and 14b are multilayered, for example, the coating liquid (coating agent) constituting the lower layer (gas barrier layer 13 side) of the corrosion prevention treatment layer may be applied to the gas barrier layer 13 and baked to form the first layer, and then the coating liquid (coating agent) constituting the upper layer of the corrosion prevention treatment layer may be applied to the first layer and baked to form the second layer.

[0121] Degreasing may be performed by spraying or immersion. Hot water modification and anodizing may be performed by immersion. For chemical conversion treatment, immersion, spraying, coating, etc. may be appropriately selected depending on the type of chemical conversion treatment.

[0122] Various methods can be used for applying coating agents with corrosion-preventive properties, including gravure coating, reverse coating, roll coating, and bar coating.

[0123] As described above, the various treatments may be applied to either both sides or one side of the metal foil, but in the case of single-sided treatment, it is preferable to apply the treatment to the side on which the sealant layer 16 is laminated. Furthermore, the above treatment may also be applied to the surface of the base layer 11, if required.

[0124] The amount of coating agent applied to form the first and second layers is 0.005 to 0.200 g / m². 2 Preferably, 0.010 to 0.100 g / m 2 This is preferable.

[0125] Furthermore, if drying curing is required, it can be carried out at a base material temperature in the range of 60 to 300°C, depending on the drying conditions of the corrosion-preventive treatment layers 14a and 14b used.

[0126] (Bonding process between the base layer 11 and the gas barrier layer 13) This process involves bonding a gas barrier layer 13, which is provided with corrosion-preventive treatment layers 14a and 14b, to a substrate layer 11 via a first adhesive layer 12a. The bonding method can be dry lamination, non-solvent lamination, wet lamination, or other techniques, using the materials that constitute the first adhesive layer 12a described above. The first adhesive layer 12a is applied in a dry coating amount of 1 to 10 g / m². 2 In the range of 2 to 7 g / m², more preferably 2 to 7 g / m² 2 It will be established within the range of [this].

[0127] (Lamination process of the second adhesive layer 12b and sealant layer 16) This process involves bonding the sealant layer 16 to the second corrosion-preventive treatment layer 14b side of the gas barrier layer 13 via a second adhesive layer 12b. Methods of bonding include wet processes and dry lamination.

[0128] In the wet process, a solution or dispersion of the adhesive constituting the second adhesive layer 12b is applied onto the second corrosion-preventive treatment layer 14b, and the solvent is evaporated at a predetermined temperature to form a dry film, or a baking treatment is performed as needed after drying. Subsequently, a sealant layer 16 is laminated to manufacture the exterior material 10. Various coating methods as exemplified above can be used as coating methods. The preferred dry application amount of the second adhesive layer 12b is the same as that of the first adhesive layer 12a.

[0129] In this case, the sealant layer 16 can be manufactured by a melt extrusion molding machine using, for example, a resin composition for forming a sealant layer containing the components of the sealant layer 16 described above. From the viewpoint of productivity, the processing speed of the melt extrusion molding machine can be set to 80 m / min or more.

[0130] (Lamination process of hydrogen sulfide adsorption layer 18) This step involves laminating a hydrogen sulfide adsorption layer 18 on the side of the sealant layer 16 opposite to the second adhesive layer 12b to obtain a laminate. The hydrogen sulfide adsorption layer 18 can be formed, for example, by using a resin composition for forming the hydrogen sulfide adsorption layer 18 containing the components of the hydrogen sulfide adsorption layer 18 described above, forming a coating film by a general coating method such as direct gravure, reverse gravure, wire bar coating, or microgravure, and drying it at 40 to 150°C for 10 to 180 seconds. The drying conditions of the coating film can be adjusted according to the type of solvent used in the resin composition for forming the hydrogen sulfide adsorption layer 18, the thickness of the hydrogen sulfide adsorption layer, etc. The hydrogen sulfide adsorption layer 18 may also be formed by extrusion using an extrusion laminating machine or the like.

[0131] (Aging process) This process involves aging (curing) the laminate. Aging the laminate promotes adhesion between the gas barrier layer 13, the second corrosion prevention treatment layer 14b, the second adhesive layer 12b, the sealant layer 16, and the hydrogen sulfide adsorption layer 18. The aging process can be carried out in a temperature range of room temperature to 100°C. The aging time is, for example, 1 to 10 days.

[0132] In this way, the exterior material 10 of this embodiment, as shown in Figure 1, can be manufactured. If the exterior material is provided with an adhesive resin layer 15 instead of the second corrosion-preventive treatment layer 14b, as in the exterior material 20 shown in Figure 2, the following steps may be included instead of the lamination process of the second adhesive layer 12b and the sealant layer 16.

[0133] (Lamination process of adhesive resin layer 15 and sealant layer 16) This step involves forming an adhesive resin layer 15 and a sealant layer 16 on the second corrosion-preventive treatment layer 14b formed in the previous step. One method for this is sand lamination of the adhesive resin layer 15 together with the sealant layer 16 using an extrusion laminating machine. Alternatively, the adhesive resin layer 15 and the sealant layer 16 may be laminated on the corrosion-preventive treatment layer 14b by a tandem lamination method or a co-extrusion method in which the adhesive resin layer 15 and the sealant layer 16 are extruded. In forming the adhesive resin layer 15 and the sealant layer 16, for example, each component is blended to satisfy the above-described configuration of the adhesive resin layer 15 and the sealant layer 16. The above-described sealant layer forming resin composition is used to form the sealant layer 16.

[0134] The adhesive resin layer 15 may also be laminated by directly extruding the dry-blended material using an extrusion laminating machine to achieve the material composition described above. Alternatively, the adhesive resin layer 15 may be laminated by extruding the granulated material, which has been melt-blended beforehand using a melt-kneading device such as a single-screw extruder, twin-screw extruder, or Brabender mixer, using an extrusion laminating machine.

[0135] The sealant layer 16 may be laminated by directly extruding a dry-blended material, which has been prepared to have the above-described material composition as a component of the resin composition for forming the sealant layer, using an extrusion laminating machine. Alternatively, the adhesive resin layer 15 and the sealant layer 16 may be laminated by a tandem lamination method or co-extrusion method, in which the adhesive resin layer 15 and the sealant layer 16 are extruded using an extrusion laminating machine after melt blending the granulated material using a melt-kneading device such as a single-screw extruder, twin-screw extruder, or Brabender mixer. Furthermore, a single sealant film may be prepared in advance as a cast film using the resin composition for forming the sealant layer, and this film may be laminated together with the adhesive resin by sand lamination. From the viewpoint of productivity, the formation speed (processing speed) of the adhesive resin layer 15 and the sealant layer 16 can be, for example, 80 m / min or more.

[0136] Next, an example of a manufacturing method for the exterior material 30 shown in Figure 3 will be described. Note that the manufacturing method for the exterior material 30 is not limited to the method described below.

[0137] The manufacturing method for the exterior material 30 of this embodiment includes the steps of: providing corrosion prevention treatment layers 14a and 14b on the gas barrier layer 13; bonding the base layer 11 and the gas barrier layer 13 using the first adhesive layer 12a; and further laminating the hydrogen sulfide adsorption layer 18 and the sealant layer 16 to produce a laminate, and optionally including a step of heat-treating the obtained laminate. Note that the steps up to bonding the base layer 11 and the gas barrier layer 13 can be carried out in the same manner as the manufacturing method for the exterior material 10 described above.

[0138] (Lamination process of hydrogen sulfide adsorption layer 18 and sealant layer 16) This step involves forming a hydrogen sulfide adsorption layer 18 and a sealant layer 16 on the second corrosion-preventive treatment layer 14b formed in the previous step. The hydrogen sulfide adsorption layer 18 and the sealant layer 16 can be laminated on the second corrosion-preventive treatment layer 14b by a tandem lamination method or co-extrusion method, in which the hydrogen sulfide adsorption layer 18 and the sealant layer 16 are extruded using an extrusion laminating machine with granules (a mixture of resin compositions forming each layer) that have been pre-melted and blended using a melt-kneading device such as a single-screw extruder, twin-screw extruder, or Brabender mixer. In forming the hydrogen sulfide adsorption layer 18 and the sealant layer 16, for example, each component is blended to satisfy the above-described configuration of the hydrogen sulfide adsorption layer 18 and the sealant layer 16. The above-described resin composition for forming the sealant layer is used for forming the sealant layer 16, and the above-described resin composition for forming the hydrogen sulfide adsorption layer 18 is used for forming the hydrogen sulfide adsorption layer 18.

[0139] This process yields a laminate in which the layers are stacked in the following order, as shown in Figure 3: base material layer 11 / first adhesive layer 12a / first corrosion prevention treatment layer 14a / gas barrier layer 13 / second corrosion prevention treatment layer 14b / hydrogen sulfide adsorption layer 18 / sealant layer 16.

[0140] (Heat treatment process) This process involves heat-treating the laminate. Heat-treating the laminate improves the adhesion between the gas barrier layer 13, the second corrosion-preventive treatment layer 14b, the hydrogen sulfide adsorption layer 18, and the sealant layer 16. Preferably, the heat treatment is performed at a temperature at least equal to or greater than the melting point of the hydrogen sulfide adsorption layer 18.

[0141] In this way, the exterior material 30 of this embodiment, as shown in Figure 3, can be manufactured.

[0142] Next, an example of a manufacturing method for the exterior material 40 shown in Figure 4 will be described. Note that the manufacturing method for the exterior material 40 is not limited to the method described below.

[0143] The manufacturing method for the exterior material 40 of this embodiment includes the steps of: providing corrosion prevention treatment layers 14a and 14b on the gas barrier layer 13; bonding the base layer 11 and the gas barrier layer 13 using the first adhesive layer 12a; laminating the second adhesive layer 12b and the first sealant layer 16a; and further laminating the hydrogen sulfide adsorption layer 18 and the second sealant layer 16b to produce a laminate, and optionally including a step of heat-treating the obtained laminate. Note that the steps up to bonding the base layer 11 and the gas barrier layer 13 can be carried out in the same manner as the manufacturing method for the exterior material 10 described above.

[0144] (Lamination process of the second adhesive layer 12b and sealant layer 16) This step involves bonding the first sealant layer 16a to the second corrosion-preventive treatment layer 14b side of the gas barrier layer 13 via the second adhesive layer 12b. This step can be carried out in the same manner as the lamination step of the second adhesive layer 12b and sealant layer 16 described above.

[0145] (Lamination process of hydrogen sulfide adsorption layer 18 and second sealant layer 16b) This step involves forming a hydrogen sulfide adsorption layer 18 and a second sealant layer 16b on the first sealant layer 16a formed in the previous step. The hydrogen sulfide adsorption layer 18 and the second sealant layer 16b can be laminated on the first sealant layer 16a by a tandem lamination method or co-extrusion method, in which the hydrogen sulfide adsorption layer 18 and the second sealant layer 16b are extruded using an extrusion laminating machine with granules (a mixture of resin compositions forming each layer) that have been pre-melted and blended using a melt-kneading device such as a single-screw extruder, twin-screw extruder, or Bravender mixer. In forming the hydrogen sulfide adsorption layer 18 and the second sealant layer 16b, for example, each component is blended so as to satisfy the configuration of the hydrogen sulfide adsorption layer 18 and the sealant layer 16 described above. The above-described resin composition for forming the sealant layer is used to form the second sealant layer 16b, and the above-described resin composition for forming the hydrogen sulfide adsorption layer 18 is used to form the hydrogen sulfide adsorption layer 18.

[0146] This process yields a laminate in which the layers are stacked in the following order, as shown in Figure 4: base material layer 11 / first adhesive layer 12a / first corrosion prevention treatment layer 14a / gas barrier layer 13 / second corrosion prevention treatment layer 14b / second adhesive layer 12b / first sealant layer 16a / hydrogen sulfide adsorption layer 18 / second sealant layer 16b.

[0147] (Heat treatment process) This process involves heat-treating the laminate. By heat-treating the laminate, the adhesion between the gas barrier layer 13, the second corrosion-preventive treatment layer 14b, the second adhesive layer 12b, the first sealant layer 16a, the hydrogen sulfide adsorption layer 18, and the second sealant layer 16b can be improved. As for the heat treatment method, it is preferable to treat at a temperature at least equal to or above the melting point of the hydrogen sulfide adsorption layer 18.

[0148] In this way, the exterior material 40 of this embodiment, as shown in Figure 4, can be manufactured.

[0149] Although preferred embodiments of the casing material for all-solid-state batteries described herein have been detailed, this disclosure is not limited to such specific embodiments, and various modifications and changes are possible within the scope of the gist of this disclosure as described in the claims.

[0150] [All-solid battery] Figure 5 is a perspective view showing one embodiment of an all-solid-state battery made using the exterior material described above. As shown in Figure 5, the all-solid-state battery 50 is composed of a battery element 52, two metal terminals (current extraction terminals) 53 for extracting current from the battery element 52 to the outside, and an exterior material 10 that encloses the battery element 52 in an airtight state. The exterior material 10 is the exterior material 10 according to the embodiment described above and is used as a container for housing the battery element 52. In the exterior material 10, the base layer 11 is the outermost layer, and the hydrogen sulfide adsorption layer 18 is the innermost layer. That is, the exterior material 10 is configured to enclose the battery element 52 inside by folding one laminate film in half and heat-sealing the periphery, or by overlapping two laminate films and heat-sealing the periphery, so that the base layer 11 is on the outside side of the all-solid-state battery 50 and the hydrogen sulfide adsorption layer 18 is on the inside side of the all-solid-state battery 50. In addition, in the all-solid-state battery 50, the outer casing material 20, outer casing material 30, or outer casing material 40 may be used instead of the outer casing material 10.

[0151] The battery element 52 has a sulfide-based solid electrolyte interposed between the positive electrode and the negative electrode. The metal terminal 53 is a part of the current collector that is exposed to the outside of the outer casing material 10, and is made of metal foil such as copper foil or aluminum foil. The metal terminal 53 is sandwiched and sealed by the outer casing material 10 which forms a container with the hydrogen sulfide adsorption layer 18 on the inside. The metal terminal 53 may also be sandwiched by the outer casing material 10 via a tab sealant. [Examples]

[0152] The present disclosure will be described in more detail below based on examples, but the present disclosure is not limited to the following examples.

[0153] [Materials used] The materials used in the examples and comparative examples are shown below.

[0154] <Substrate layer (thickness 15 μm)> A nylon (Ny) film (manufactured by Toyobo Co., Ltd.) was used.

[0155] <First adhesive layer (thickness 5 μm, on the substrate layer side)> A polyurethane adhesive (manufactured by Toyo Ink Co., Ltd.) was used, which combined a polyester polyol-based main component with a tolylene diisocyanate adduct-type curing agent.

[0156] <First corrosion-preventive treatment layer (substrate layer side) and second corrosion-preventive treatment layer (sealant layer side)> (CL-1): A "sodium polyphosphate stabilized cerium oxide sol" was used, which was prepared by adjusting the solid content to 10% by mass using distilled water as the solvent. The sodium polyphosphate stabilized cerium oxide sol was obtained by mixing 10 parts by mass of sodium phosphoric acid with 100 parts by mass of cerium oxide. (CL-2): A composition consisting of 90% by mass of "polyallylamine (manufactured by Nitto Boseki Co., Ltd.)" and 10% by mass of "polyglycerol polyglycidyl ether (manufactured by Nagase ChemteX Corporation)" was used, adjusted to a solid content concentration of 5% by mass using distilled water as a solvent.

[0157] <Gas barrier layer (thickness 40 μm)> Annealed and degreased soft aluminum foil (manufactured by Toyo Aluminum Co., Ltd., "8079 material") was used.

[0158] <Adhesive resin layer (thickness 20 μm)> As the adhesive resin, a random polypropylene (PP)-based acid-modified polypropylene resin composition (manufactured by Mitsui Chemicals, Inc.) was used.

[0159] <Sealant layer (thickness 60 μm)> A polypropylene-polyethylene random copolymer (manufactured by Prime Polymer, trade name: F744NP) was used as the resin composition for forming the sealant layer.

[0160] <Hydrogen sulfide adsorption layer> A resin composition for forming a hydrogen sulfide adsorption layer was obtained by using the following polyolefin solution, hydrogen sulfide adsorbent, and curing agent in the combinations shown in Table 1. (Polyolefin solution) • Liquid A: Manufactured by Toyobo Co., Ltd., product name PMA-T, solvent-based, acid value 17 mg KOH / g, melting point 95°C, maleic acid-modified polypropylene • Liquid B: Manufactured by Toyobo Co., Ltd., product name NZ-1029, aqueous dispersion system, acid value 12 mg KOH / g, melting point 95°C, maleic acid-modified polypropylene Liquid C: Manufactured by Toyobo Co., Ltd., product name PMA-KH, solvent-based, acid value 12 mg KOH / g, melting point 80°C, maleic acid-modified polypropylene Liquid D: Manufactured by Toyobo Co., Ltd., product name PMA-L, solvent-based, acid value 17 mg KOH / g, melting point 70°C, maleic acid-modified polypropylene • Liquid E: Manufactured by Toyobo Co., Ltd., product name NZ-1022, aqueous dispersion system, acid value 17 mg KOH / g, melting point 125℃, maleic acid-modified polypropylene Liquid F: Manufactured by Toyobo Co., Ltd., product name Byron 20SS, solvent-based, acid value 6 mg KOH / g, melting point 170°C, polyester polyol (Hydrogen sulfide adsorbent) Agent A: Manufactured by Sinanen Zeomic Co., Ltd., product name Dashlight ZH, average particle size (D50) 1.5 μm Agent B: Manufactured by Sinanen Zeomic Co., Ltd., product name Dashlight CZU, average particle size (D50) 4 μm • Agent C: Manufactured by Rasa Industries Co., Ltd., product name: Shoecleanse KD-211, grade GU, average particle size (D50) 0.8 μm (Hardening agent) • Isocyanate: Manufactured by Tosoh Corporation, product name Coronate 2031, in an amount equal to 1 equivalent for the acidic groups in maleic acid-modified polypropylene or the hydroxyl groups in polyester polyols. • Carbodilite: Manufactured by Nisshinbo Holdings Inc., product name V-02-L2, 0.5 equivalents relative to the acidic groups in maleic acid-modified polypropylene. • Oxazoline: Manufactured by Nippon Shokubai Co., Ltd., trade name WS-300, 0.5 equivalents relative to the acidic groups in maleic acid-modified polypropylene.

[0161] [Manufacturing of exterior materials] (Examples 1 and 4-17, Comparative Examples 1 and 2) First, the first and second corrosion prevention treatment layers were provided on the gas barrier layer by the following procedure. That is, (CL-1) was applied to both surfaces of the gas barrier layer by microgravure coating so that the dry coating amount was 70 mg / m 2 and baked at 200°C in a drying unit. Next, (CL-2) was applied to the obtained layer by microgravure coating so that the dry coating amount was 20 mg / m 2 to form a composite layer composed of (CL-1) and (CL-2) as the first and second corrosion prevention treatment layers. This composite layer exhibits corrosion prevention performance by compounding two types of (CL-1) and (CL-2).

[0162] Next, the side of the gas barrier layer provided with the first and second corrosion prevention treatment layers on the first corrosion prevention treatment layer side was attached to the base material layer using a polyurethane-based adhesive (the first adhesive layer) by a dry lamination method. The lamination of the gas barrier layer and the base material layer was performed by applying a polyurethane-based adhesive on the surface of the first corrosion prevention treatment layer side of the gas barrier layer so that the thickness after curing was 5 μm, drying at 80°C for 1 minute, then laminating with the base material layer, and aging at 60°C for 72 hours.

[0163] Next, the laminate of the barrier layer and the base material layer was set in the unwinding section of an extrusion laminator, and an adhesive resin layer (thickness 20 μm) and a sealant layer (thickness 60 μm) were laminated in this order by co-extrusion under processing conditions of 270°C and 100 m / min on the second corrosion prevention treatment layer. The adhesive resin layer and the sealant layer were prepared in advance by using a twin-screw extruder to produce compounds of various materials, and were used for the above extrusion lamination through the processes of water cooling and pelletizing.

[0164] Next, a resin composition for forming a hydrogen sulfide adsorption layer was applied to the surface of the sealant layer by the gravure coating method so that the film thickness after drying was 5 μm, dried at 100°C for 1 minute, and then aged at 60°C for 72 hours to form a hydrogen sulfide adsorption layer.

[0165] The laminate obtained in this manner was heat-treated to a maximum temperature of 190°C to produce an exterior material (a laminate consisting of a base layer, a first adhesive layer, a first corrosion-preventive treatment layer, a gas barrier layer, a second corrosion-preventive treatment layer, an adhesive resin layer, a sealant layer, and a hydrogen sulfide adsorption layer).

[0166] (Example 2) A laminate of a barrier layer and a base layer was prepared in the same manner as in Example 1. Next, the laminate of the barrier layer and the base layer was set in the unwinding section of an extrusion laminating machine, and a hydrogen sulfide adsorption layer (thickness 20 μm) and a sealant layer (thickness 60 μm) were laminated in that order on the second corrosion-preventive treatment layer by co-extrusion at processing conditions of 270°C and 100 m / min. The hydrogen sulfide adsorption layer and the sealant layer were prepared in advance using a twin-screw extruder as compounds of the materials to form each layer, and after undergoing a water-cooling and pelletizing process, they were used in the above extrusion lamination.

[0167] The laminate obtained in this manner was heat-treated to a maximum temperature of 190°C to produce an exterior material (a laminate consisting of a base layer, a first adhesive layer, a first corrosion-preventive treatment layer, a gas barrier layer, a second corrosion-preventive treatment layer, a hydrogen sulfide adsorption layer, and a sealant layer).

[0168] (Example 3) A laminate of a barrier layer and a base layer was prepared in the same manner as in Example 1. Next, in the same manner as in Example 1, the laminate of the barrier layer and the base layer was set in the unwinding section of an extrusion laminating machine and co-extruded onto a second corrosion-preventive treatment layer at processing conditions of 270°C and 100 m / min to obtain a laminate in which an adhesive resin layer (thickness 20 μm), a first sealant layer (thickness 20 μm), a hydrogen sulfide adsorption layer (thickness 5 μm), and a second sealant layer (thickness 35 μm) were laminated in this order.

[0169] [Measurement of heat seal strength] Samples of the fabricated exterior material were cut to a size of 50 mm (TD) x 100 mm (MD). These samples were folded in half, sandwiching a 50 mm x 50 mm piece of chemically treated aluminum foil between them. The end opposite the folded portion was heat-sealed over a width of 10 mm at 180°C / 0.6 MPa / 10 seconds. Subsequently, a 15 mm wide section was cut from the longitudinal center of the heat-sealed portion (see Figure 6) to prepare a sample for heat seal strength measurement. This heat seal strength measurement sample was subjected to a T-shaped peel test using a tensile testing machine (manufactured by Shimadzu Corporation) at room temperature (25°C) and 80°C at a tensile speed of 50 mm / min. Based on the results obtained, the heat seal strength (burst strength) was evaluated according to the following evaluation criteria. A: Heat seal strength of 20N / 15mm or more B: Heat seal strength of 15N / 15mm or more, and less than 20N / 15mm. C: Heat seal strength less than 15N / 15mm

[0170] [Evaluation of hydrogen sulfide (H2S) absorption] The outer packaging material was cut to a size of 50 mm x 50 mm to serve as a sample for evaluating hydrogen sulfide absorption. This sample was placed in a 2 L Tedlar bag, and the Tedlar bag was sealed. 2 L of hydrogen sulfide gas with a concentration of 20 ppm by mass was poured into the Tedlar bag, and it was left at room temperature (25°C) for 144 hours. The hydrogen sulfide concentration inside the Tedlar bag after 144 hours was measured. The measurement results are shown in Table 1.

[0171] [Table 1] [Explanation of symbols]

[0172] 10, 20, 30, 40… Outer packaging material for all-solid-state batteries, 11… Base material layer, 12a… First adhesive layer, 12b… Second adhesive layer, 13… Gas barrier layer, 14a… First corrosion prevention treatment layer, 14b… Second corrosion prevention treatment layer, 15… Adhesive resin layer, 16… Sealant layer, 16a… First sealant layer, 16b… Second sealant layer, 17… Protective layer, 18… Hydrogen sulfide adsorption layer, 50… All-solid-state battery, 52… Battery element, 53… Metal terminal.

Claims

1. An exterior material for an all-solid-state battery comprising at least a base layer, a gas barrier layer, a sealant layer, and a hydrogen sulfide adsorption layer, The hydrogen sulfide adsorption layer is located on the surface of the sealant layer opposite to the gas barrier layer. The hydrogen sulfide adsorption layer comprises a modified polyolefin resin, a hydrogen sulfide adsorbent, and at least one selected from the group consisting of isocyanate compounds, carbodiimide compounds, and oxazoline compounds, and has a thickness of 0.5 μm or more and less than 10 μm, as an outer casing material for an all-solid-state battery.

2. The exterior material for an all-solid-state battery according to claim 1, wherein the hydrogen sulfide adsorption layer is disposed on the surface of the sealant layer on the gas barrier layer side.

3. The exterior material for an all-solid-state battery according to claim 1 or 2, wherein the modified polyolefin resin is an acid-modified polyolefin resin.

4. The exterior material for a solid-state battery according to claim 3, wherein the acid-modified polyolefin resin is a maleic anhydride-modified polypropylene resin.

5. The casing material for all-solid-state batteries according to claim 3 or 4, wherein the acid value of the acid-modified polyolefin resin is 2 to 30 mg KOH / g.

6. The casing material for an all-solid-state battery according to any one of claims 3 to 5, wherein the melting point of the acid-modified polyolefin resin is 70 to 150°C.

7. The outer casing material for an all-solid-state battery according to any one of claims 1 to 6, wherein the content of the hydrogen sulfide adsorbent is 1 to 50% by mass based on the total amount of the hydrogen sulfide adsorption layer.

8. The exterior material for an all-solid-state battery according to any one of claims 1 to 7, wherein the hydrogen sulfide adsorption layer is formed by coating it with a coating solution containing at least the modified polyolefin resin and the hydrogen sulfide adsorbent.

9. The exterior material for an all-solid-state battery according to any one of claims 1 to 8, wherein the thickness of the hydrogen sulfide adsorption layer is less than 5 μm.

10. Battery elements containing a sulfide-based solid electrolyte, A current extraction terminal extending from the aforementioned battery element, An enclosure material for an all-solid-state battery according to any one of claims 1 to 9, which clamps the current extraction terminal and houses the battery element, A solid-state battery equipped with [specific features / features].

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