Exterior material for power storage device, method for manufacturing exterior material for power storage device, and power storage device

Abstract

To provide an exterior material for a power storage device which maintains high adhesion between a barrier layer having an anticorrosive film and an adhesive layer, even when moisture enters inside a power storage device.SOLUTION: An exterior material for a power storage device is composed of a laminate having at least a base material layer, a barrier layer, an adhesive layer and a heat-fusible resin layer in this order, wherein the adhesive layer is a cured product of a resin composition containing a compound having an isocyanate group, and has an anticorrosive film on the surface on at least the adhesive layer side of the barrier layer, when the anticorrosive film is analyzed using time-of-flight secondary ion mass spectrometry, a ratio PPO3 / CrPO4 of peak intensity PPO3 derived from PO3- to peak intensity PCrPO4 derived from CrPO4 is within a range of 6 to 120.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to an exterior material for an electricity storage device, a method for manufacturing an exterior material for an electricity storage device, and an electricity storage device. [Background technology]

[0002] Various types of electricity storage devices have been developed. In these electricity storage devices, electricity storage device elements composed of electrodes, electrolytes, etc. need to be sealed with an exterior material, etc. Metal exterior materials are often used as exterior materials for electricity storage devices.

[0003] In recent years, with the increasing performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, and the like, there has been a demand for electricity storage devices with a variety of shapes. Furthermore, electricity storage devices are also being required to be thinner and lighter. However, it is difficult for the metal exterior materials that have been widely used up until now to keep up with the diversification of electricity storage device shapes. Furthermore, because they are made of metal, there is a limit to how light the exterior materials can be.

[0004] Therefore, a film-like laminate in which a base layer, a barrier layer, and a heat-sealable resin layer are laminated in this order has been proposed as an exterior material for an electricity storage device that can be easily processed into a variety of shapes and can be made thinner and lighter (see, for example, Patent Document 1).

[0005] In such a film-like electrical storage device exterior material, a recess is generally formed by molding, and electrical storage device elements such as electrodes and electrolyte are placed in the space formed by the recess, and the heat-sealable resin layers are heat-sealed to each other to obtain an electrical storage device in which the electrical storage device elements are housed inside the electrical storage device exterior material. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-287971 Summary of the Invention [Problem to be solved by the invention]

[0007] Moisture may penetrate during the manufacture of an electricity storage device or through the heat-sealed joints between the heat-sealable resin layers of the exterior material of the electricity storage device. When moisture penetrates into the interior of an electricity storage device, it may react with the electrolyte and generate an acidic substance. For example, the electrolyte used in lithium-ion electricity storage devices contains fluorine compounds (LiPF6, LiBF4, etc.) that act as electrolytes, and it is known that when fluorine compounds react with water, hydrogen fluoride is generated.

[0008] The barrier layer of an electrical storage device packaging material formed of a film-like laminate is usually composed of a metal foil or the like, and has a problem of being easily corroded when the barrier layer comes into contact with acid. As a technique for improving the corrosion resistance of such an electrical storage device packaging material, a technique of using a barrier layer having a corrosion-resistant coating formed on the surface by chemical conversion treatment is known.

[0009] Conventionally, various methods have been known as chemical conversion treatments for forming corrosion-resistant films, such as chromate treatment using a chromium compound such as chromium oxide, and phosphate treatment using a phosphate compound.

[0010] However, through extensive investigations, the inventors of the present disclosure have found that when a conventional barrier layer having a corrosion-resistant coating is laminated to a heat-sealable resin layer via an adhesive layer, if an electrolyte solution adheres to the electrical storage device packaging material, high adhesion between the corrosion-resistant coating of the barrier layer and the adhesive layer (i.e., adhesion at the interface between the corrosion-resistant coating and the adhesive layer) cannot be maintained. In particular, if moisture penetrates into the interior of the electrical storage device and the electrolyte solution contains moisture, hydrogen fluoride is generated, corroding the barrier layer, making it difficult to maintain high adhesion between the barrier layer having the corrosion-resistant coating and the adhesive layer.

[0011] Under these circumstances, a primary object of the present disclosure is to provide a packaging material for an electricity storage device that maintains high adhesion between a barrier layer provided with a corrosion-resistant coating and an adhesive layer even when moisture penetrates into the interior of the electricity storage device. Another object of the present disclosure is to provide a method for manufacturing the packaging material for an electricity storage device, and an electricity storage device using the packaging material for an electricity storage device. [Means for solving the problem]

[0012] The inventors of the present disclosure conducted extensive research to solve the above-mentioned problems, and as a result, they found that in a packaging material for an electricity storage device, which is a laminate including at least a base layer, a barrier layer, an adhesive layer, and a heat-sealable resin layer in this order, and which includes a corrosion-resistant coating on at least the adhesive layer side of the barrier layer, when a specific curing agent is used to form the adhesive layer and a specific corrosion-resistant coating is further used, high adhesion between the barrier layer including the corrosion-resistant coating and the adhesive layer is maintained even if moisture penetrates into the electricity storage device. The present disclosure is an invention that was completed based on these findings and through further investigation.

[0013] That is, the present disclosure provides the inventions of the following aspects. The laminate is composed of at least a base layer, a barrier layer, an adhesive layer, and a heat-sealable resin layer in this order, the adhesive layer is a cured product of a resin composition containing a compound having an isocyanate group, a corrosion-resistant coating is provided on at least the adhesive layer side of the barrier layer; When the corrosion-resistant coating was analyzed using time-of-flight secondary ion mass spectrometry, it was found that CrPO4 - The peak intensity P derived from CrPO4 PO3 for - The peak intensity P derived from PO3 The ratio P PO3 / CrPO4 is in the range of 6 to 120, Analysis of the corrosion-resistant coating by X-ray photoelectron spectroscopy revealed a peak P attributed to C1s of the O-C=O bond in the range of 287 eV to 290 eV. OCO and a peak P at 285 eV due to C1s of the C-C bond. C-C is detected, The peak P OCO The height of the peak P C-C The peak height ratio P is obtained by dividing OCO / C-C is in the range of 0.10 or more and 0.50 or less. [Effects of the Invention]

[0014] According to the present disclosure, it is possible to provide a packaging material for an electricity storage device in which high adhesion between a barrier layer provided with a corrosion-resistant coating and an adhesive layer is maintained even when moisture penetrates into the interior of the electricity storage device. The present disclosure also makes it possible to provide a method for manufacturing the packaging material for an electricity storage device, and an electricity storage device using the packaging material for an electricity storage device. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. [Figure 2] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. [Figure 3] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. [Figure 4] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0016] The packaging material for an electricity storage device according to the present disclosure is composed of a laminate including at least a base layer, a barrier layer, an adhesive layer, and a heat-sealable resin layer in this order. The adhesive layer is a cured product of a resin composition containing a compound having an isocyanate group. The barrier layer is provided with a corrosion-resistant coating on at least the surface thereof facing the adhesive layer. When the corrosion-resistant coating is analyzed using time-of-flight secondary ion mass spectrometry, it is found that the corrosion-resistant coating is - The peak intensity P derived from CrPO4 PO3 for - The peak intensity P derived from PO3 The ratio P PO3 / CrPO4 is in the range of 6 to 120, and the analysis of the corrosion-resistant coating by X-ray photoelectron spectroscopy shows a peak P OCO and a peak P at 285 eV due to C1s of the C-C bond. C-C is detected, and peak P OCO The height of the peak P C-C The peak height ratio P is obtained by dividing OCO / C-C is in the range of 0.10 or more and 0.50 or less.

[0017] Hereinafter, with reference to FIGS. 1 to 4, the packaging material for an electricity storage device of the present disclosure, the method for manufacturing the packaging material for an electricity storage device, and the electricity storage device using the packaging material for an electricity storage device will be described in detail.

[0018] In this specification, numerical ranges indicated with "to" mean "greater than or equal to" or "less than or equal to." For example, the expression 2 to 15 mm means 2 mm or greater and 15 mm or less.

[0019] 1.Layer structure of exterior materials for energy storage devices As shown in Figures 1 to 4, for example, the packaging material for an electricity storage device according to the present disclosure is composed of a laminate having at least a base material layer 1, a barrier layer 3, an adhesive layer 5, and a heat-sealable resin layer 4 in this order. In the packaging material for an electricity storage device according to the present disclosure, the base material layer 1 is the outermost layer, and the heat-sealable resin layer 4 is the innermost layer. That is, when assembling the electricity storage device, the heat-sealable resin layers 4 located on the periphery of the electricity storage device elements are heat-sealed to each other to seal the electricity storage device elements, thereby sealing the electricity storage device elements.

[0020] A corrosion-resistant coating is provided on at least one surface of the barrier layer 3. The corrosion-resistant coating contains chromium. FIG. 1 is a schematic diagram showing an electrical storage device packaging material according to the present disclosure that is provided with a corrosion-resistant coating 3a on the surface of the barrier layer 3 that faces the heat-sealable resin layer 4. FIGS. 2 to 4 are schematic diagrams showing electrical storage device packaging materials according to the present disclosure that are provided with corrosion-resistant coatings 3a and 3b on both surfaces of the barrier layer 3. As described below, the electrical storage device packaging material according to the present disclosure may be provided with the corrosion-resistant coating 3a only on the surface of the barrier layer 3 that faces the heat-sealable resin layer 4, or may be provided with the corrosion-resistant coatings 3a and 3b on both surfaces of the barrier layer 3.

[0021] As shown in Figures 3 and 4, the packaging material for an electricity storage device of the present disclosure may optionally include an adhesive layer 2 between a base material layer 1 and a barrier layer 3 for the purpose of enhancing adhesion therebetween. Furthermore, as shown in Figure 4, for the purpose of improving design, electrolyte resistance, abrasion resistance, formability, etc., a surface coating layer 6 may optionally be provided on the side of the base material layer 1 opposite to the barrier layer 3.

[0022] The thickness of the laminate constituting the electrical storage device packaging material 10 is not particularly limited, but the upper limit is preferably about 180 μm or less, about 155 μm or less, or about 120 μm or less from the viewpoint of cost reduction, improving energy density, etc., and the lower limit is preferably about 35 μm or more, about 45 μm or more, or about 60 μm or more from the viewpoint of maintaining the function of the electrical storage device packaging material to protect the electrical storage device elements, and preferred ranges include, for example, about 35 to 180 μm, about 35 to 155 μm, about 35 to 120 μm, about 45 to 180 μm, about 45 to 155 μm, about 45 to 120 μm, about 60 to 180 μm, about 60 to 155 μm, or about 60 to 120 μm.

[0023] In the packaging material for an electricity storage device, the MD and TD of the barrier layer 3 described below can usually be determined during the manufacturing process. For example, when the barrier layer 3 is made of aluminum alloy foil, linear streaks called rolling marks are formed on the surface of the aluminum alloy foil in the rolling direction (RD) of the aluminum alloy foil. Since the rolling marks extend along the rolling direction, the rolling direction of the aluminum alloy foil can be determined by observing the surface of the aluminum alloy foil. Furthermore, in the manufacturing process of a laminate, the MD of the laminate usually coincides with the RD of the aluminum alloy foil, so the MD of the laminate can be identified by observing the surface of the aluminum alloy foil of the laminate and identifying the rolling direction (RD) of the aluminum alloy foil. Furthermore, since the TD of the laminate is perpendicular to the MD of the laminate, the TD of the laminate can also be identified.

[0024] 2. Each layer that forms the exterior material for the energy storage device [Base material layer 1] In the present disclosure, the substrate layer 1 is a layer provided for the purpose of allowing the packaging material for an electricity storage device to function as a substrate, etc. The substrate layer 1 is located on the outer layer side of the packaging material for an electricity storage device.

[0025] There are no particular limitations on the material forming the base layer 1, as long as it functions as a base, i.e., has at least insulating properties. The base layer 1 can be formed using, for example, a resin, which may contain additives described below.

[0026] When the base layer 1 is formed of a resin, the base layer 1 may be, for example, a resin film formed of a resin, or may be formed by applying a resin. The resin film may be an unstretched film or a stretched film. Examples of stretched films include uniaxially stretched films and biaxially stretched films, with biaxially stretched films being preferred. Examples of stretching methods for forming biaxially stretched films include sequential biaxial stretching, inflation, and simultaneous biaxial stretching. Examples of methods for applying a resin include roll coating, gravure coating, and extrusion coating.

[0027] Examples of resins that form the base layer 1 include polyester, polyamide, polyolefin, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, and phenolic resin, as well as modified versions of these resins. The resin that forms the base layer 1 may also be a copolymer of these resins or a modified version of the copolymer. Furthermore, it may also be a mixture of these resins.

[0028] Of these, preferred resins for forming the base layer 1 include polyester and polyamide.

[0029] Specific examples of polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymer polyesters. Examples of copolymer polyesters include copolymer polyesters in which ethylene terephthalate is the main repeating unit. Specific examples include copolymer polyesters in which ethylene terephthalate is the main repeating unit and is polymerized with ethylene isophthalate (hereinafter abbreviated as polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate), and polyethylene (terephthalate / decanedicarboxylate). These polyesters may be used alone or in combination of two or more.

[0030] Specific examples of polyamides include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and copolymers of nylon 6 and nylon 66; hexamethylenediamine-isophthalic acid-terephthalic acid copolymer polyamides such as nylon 6I, nylon 6T, nylon 6IT, and nylon 6I6T (where I represents isophthalic acid and T represents terephthalic acid), which contain structural units derived from terephthalic acid and / or isophthalic acid; and aromatic polyamides such as polyamide MXD6 (polymetaxylylene adipamide); alicyclic polyamides such as polyamide PACM6 (polybis(4-aminocyclohexyl)methane adipamide); polyamides copolymerized with a lactam component or an isocyanate component such as 4,4'-diphenylmethane diisocyanate; polyesteramide copolymers and polyetheresteramide copolymers, which are copolymers of copolymerized polyamides with polyesters or polyalkylene ether glycols; and polyamides such as copolymers of these copolymers. These polyamides may be used singly or in combination of two or more.

[0031] The base layer 1 preferably includes at least one of a polyester film, a polyamide film, and a polyolefin film, preferably includes at least one of a stretched polyester film, a stretched polyamide film, and a stretched polyolefin film, more preferably includes at least one of a stretched polyethylene terephthalate film, a stretched polybutylene terephthalate film, a stretched nylon film, and a stretched polypropylene film, and even more preferably includes at least one of a biaxially oriented polyethylene terephthalate film, a biaxially oriented polybutylene terephthalate film, a biaxially oriented nylon film, and a biaxially oriented polypropylene film.

[0032] The base material layer 1 may be a single layer, or may be composed of two or more layers. When the base material layer 1 is composed of two or more layers, the base material layer 1 may be a laminate in which resin films are laminated with an adhesive or the like, or a laminate of resin films formed by co-extrusion of resins into two or more layers. Furthermore, a laminate of resin films formed by co-extrusion of resins into two or more layers may be used as the base material layer 1 without being stretched, or may be uniaxially or biaxially stretched to form the base material layer 1.

[0033] Specific examples of laminates of two or more resin films in the base layer 1 include laminates of polyester film and nylon film, laminates of two or more nylon films, and laminates of two or more polyester films. Preferably, laminates of stretched nylon film and stretched polyester film, laminates of two or more stretched nylon films, and laminates of two or more stretched polyester films are preferred. For example, when the base layer 1 is a laminate of two resin films, a laminate of polyester resin film and polyester resin film, a laminate of polyamide resin film and polyamide resin film, or a laminate of polyester resin film and polyamide resin film is preferred. A laminate of polyethylene terephthalate film and polyethylene terephthalate film, a laminate of nylon film and nylon film, or a laminate of polyethylene terephthalate film and nylon film is more preferred. Furthermore, when the base layer 1 is a laminate of two or more resin films, it is preferred that the polyester resin film be located as the outermost layer of the base layer 1, because polyester resins are less likely to discolor when an electrolyte solution adheres to their surface.

[0034] When the base layer 1 is a laminate of two or more resin film layers, the two or more resin film layers may be laminated via an adhesive. Examples of preferred adhesives include those similar to those exemplified for adhesive layer 2 described below. The method for laminating two or more resin film layers is not particularly limited, and known methods can be used, such as dry lamination, sandwich lamination, extrusion lamination, and thermal lamination, with dry lamination being preferred. When laminating using the dry lamination method, it is preferable to use a polyurethane adhesive as the adhesive. In this case, the thickness of the adhesive may be, for example, about 2 to 5 μm. Alternatively, an anchor coat layer may be formed on the resin film before lamination. Examples of the anchor coat layer include those similar to those exemplified for adhesive layer 2 described below. In this case, the thickness of the anchor coat layer may be, for example, about 0.01 to 1.0 μm.

[0035] Furthermore, additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, and antistatic agents may be present on at least one of the surface and the interior of the base material layer 1. Only one type of additive may be used, or two or more types may be mixed and used.

[0036] In the present disclosure, from the viewpoint of improving the formability of the exterior material for an electrical storage device, it is preferable that a lubricant be present on the surface of the base layer 1. The lubricant is not particularly limited, but preferably an amide-based lubricant is used. Specific examples of amide-based lubricants include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides. Specific examples of saturated fatty acid amides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide. Specific examples of unsaturated fatty acid amides include oleic acid amide and erucic acid amide. Specific examples of substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide. Specific examples of methylolamides include methylol stearic acid amide. Specific examples of saturated fatty acid bisamides include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipamide, and N,N'-distearyl sebacic acid amide. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipamide, and N,N'-dioleyl sebacic acid amide. Specific examples of fatty acid ester amides include stearamidoethyl stearate. Specific examples of aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, N,N'-distearyl isophthalic acid amide, etc. The lubricants may be used singly or in combination of two or more.

[0037] When a lubricant is present on the surface of the base layer 1, the amount of the lubricant is not particularly limited, but is preferably about 3 mg / m 2 or more, more preferably 4 to 15 mg / m 2 approximately, more preferably 5 to 14 mg / m 2 The degree of

[0038] The lubricant present on the surface of the base layer 1 may be a lubricant exuded from the resin that constitutes the base layer 1, or a lubricant applied to the surface of the base layer 1.

[0039] The thickness of the base layer 1 is not particularly limited as long as it functions as a base, but may be, for example, about 3 to 50 μm, and preferably about 10 to 35 μm. When the base layer 1 is a laminate of two or more resin films, the thickness of each resin film constituting each layer is preferably about 2 to 25 μm.

[0040] [Adhesive layer 2] In the packaging material for an electricity storage device of the present disclosure, the adhesive layer 2 is a layer that is provided between the base layer 1 and the barrier layer 3 as needed for the purpose of increasing the adhesion between them.

[0041] The adhesive layer 2 is formed from an adhesive capable of bonding the base material layer 1 and the barrier layer 3. There are no limitations on the adhesive used to form the adhesive layer 2, and it may be any of a chemical reaction type, a solvent evaporation type, a hot melt type, a hot pressure type, etc. It may also be a two-component curing adhesive (two-component adhesive), a one-component curing adhesive (one-component adhesive), or a resin that does not involve a curing reaction. The adhesive layer 2 may be a single layer or multiple layers.

[0042] Specific examples of adhesive components contained in the adhesive include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymer polyesters; polyethers; polyurethanes; epoxy resins; phenolic resins; polyamides such as nylon 6, nylon 66, nylon 12, and copolymer polyamides; polyolefin-based resins such as polyolefins, cyclic polyolefins, acid-modified polyolefins, and acid-modified cyclic polyolefins; polyvinyl acetate; cellulose; (meth)acrylic resins; polyimides; polycarbonates; amino resins such as urea resins and melamine resins; rubbers such as chloroprene rubber, nitrile rubber, and styrene-butadiene rubber; and silicone resins. These adhesive components may be used alone or in combination. Among these adhesive components, polyurethane adhesives are preferred. Furthermore, the adhesive strength of these adhesive component resins can be increased by using an appropriate curing agent in combination. The curing agent is selected appropriately from polyisocyanates, multifunctional epoxy resins, oxazoline group-containing polymers, polyamine resins, acid anhydrides, and the like, depending on the functional groups of the adhesive components.

[0043] Examples of polyurethane adhesives include polyurethane adhesives containing a base agent containing a polyol compound and a curing agent containing an isocyanate compound. Preferred examples include two-component curing polyurethane adhesives that use a polyol such as polyester polyol, polyether polyol, or acrylic polyol as the base agent and an aromatic or aliphatic polyisocyanate as the curing agent. Furthermore, as the polyol compound, it is preferable to use a polyester polyol that has hydroxyl groups on the side chain in addition to the terminal hydroxyl groups of the repeating unit. Forming the adhesive layer 2 from a polyurethane adhesive provides the electrical storage device exterior material with excellent electrolyte resistance, preventing peeling of the base layer 1 even when the electrolyte adheres to the side surface.

[0044] Furthermore, the adhesive layer 2 may contain other components as long as they do not impair adhesion, and may contain colorants, thermoplastic elastomers, tackifiers, fillers, and the like. When the adhesive layer 2 contains a colorant, the exterior material for an electricity storage device can be colored. Known colorants such as pigments and dyes can be used as the colorant. Furthermore, only one type of colorant may be used, or two or more types may be mixed together.

[0045] The type of pigment is not particularly limited as long as it does not impair the adhesiveness of the adhesive layer 2. Examples of organic pigments include azo-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigothioindigo-based, perinone-perylene-based, isoindolenine-based, and benzimidazolone-based pigments, while examples of inorganic pigments include carbon black-based, titanium oxide-based, cadmium-based, lead-based, chromium oxide-based, and iron-based pigments, and other examples include finely powdered mica and fish scale foil.

[0046] Among colorants, carbon black is preferred in order to give the exterior appearance of the electrical storage device packaging material a black color, for example.

[0047] The average particle size of the pigment is not particularly limited and may be, for example, about 0.05 to 5 μm, and preferably about 0.08 to 2 μm. The average particle size of the pigment is the median size measured with a laser diffraction / scattering particle size distribution measuring device.

[0048] The content of the pigment in the adhesive layer 2 is not particularly limited as long as it colors the packaging material for an electricity storage device, and may be, for example, about 5 to 60 mass %, and preferably 10 to 40 mass %.

[0049] The thickness of the adhesive layer 2 is not particularly limited as long as it can bond the base layer 1 and the barrier layer 3 together, but the lower limit is, for example, about 1 μm or more, or about 2 μm or more, and the upper limit is about 10 μm or less, or about 5 μm or less, and preferred ranges are about 1 to 10 μm, about 1 to 5 μm, about 2 to 10 μm, or about 2 to 5 μm.

[0050] [Colored layer] The colored layer is a layer (not shown) that is provided between the base material layer 1 and the barrier layer 3 as needed. When the adhesive layer 2 is provided, a colored layer may be provided between the base material layer 1 and the adhesive layer 2, or between the adhesive layer 2 and the barrier layer 3. Alternatively, a colored layer may be provided on the outside of the base material layer 1. By providing a colored layer, the packaging material for an electricity storage device can be colored.

[0051] The colored layer can be formed, for example, by applying ink containing a colorant to the surface of the base layer 1, the surface of the adhesive layer 2, or the surface of the barrier layer 3. Known colorants such as pigments and dyes can be used. Furthermore, only one type of colorant may be used, or two or more types may be mixed together.

[0052] Specific examples of the colorant contained in the colored layer include the same as those exemplified in the section [Adhesive layer 2].

[0053] [Barrier layer 3] In the packaging material for an electricity storage device, the barrier layer 3 is a layer that at least prevents the penetration of moisture.

[0054] Examples of the barrier layer 3 include metal foils, vapor-deposited films, and resin layers having barrier properties. Vapor-deposited films include metal vapor-deposited films, inorganic oxide vapor-deposited films, and carbon-containing inorganic oxide vapor-deposited films. Resin layers include fluorine-containing resins such as polyvinylidene chloride, polymers mainly composed of chlorotrifluoroethylene (CTFE), polymers mainly composed of tetrafluoroethylene (TFE), polymers having fluoroalkyl groups, and polymers mainly composed of fluoroalkyl units, as well as ethylene-vinyl alcohol copolymers. Examples of the barrier layer 3 also include resin films comprising at least one of these vapor-deposited films and resin layers. The barrier layer 3 may comprise multiple layers. The barrier layer 3 preferably includes a layer composed of a metal material. Specific examples of metal materials constituting the barrier layer 3 include aluminum alloys, stainless steel, titanium steel, and steel plates. When used as a metal foil, the barrier layer 3 preferably includes at least one of aluminum alloy foil and stainless steel foil.

[0055] From the viewpoint of improving the formability of the electrical storage device packaging material, the aluminum alloy foil is preferably a soft aluminum alloy foil made of, for example, an annealed aluminum alloy, and from the viewpoint of further improving formability, an iron-containing aluminum alloy foil is preferred. In the iron-containing aluminum alloy foil (100% by mass), the iron content is preferably 0.1 to 9.0% by mass, more preferably 0.5 to 2.0% by mass. By setting the iron content to 0.1% by mass or more, an electrical storage device packaging material with better formability can be obtained. By setting the iron content to 9.0% by mass or less, an electrical storage device packaging material with better flexibility can be obtained. Examples of soft aluminum alloy foils include aluminum alloy foils having a composition specified in JIS H4160:1994 A8021H-O, JIS H4160:1994 A8079H-O, JIS H4000:2014 A8021P-O, or JIS H4000:2014 A8079P-O. Silicon, magnesium, copper, manganese, etc. may be added as needed. Softening can be achieved by annealing or other methods.

[0056] Examples of stainless steel foil include austenitic, ferritic, austenitic-ferritic, martensitic, and precipitation hardened stainless steel foils. From the viewpoint of providing an exterior material for an electricity storage device that has excellent formability, the stainless steel foil is preferably made of austenitic stainless steel.

[0057] Specific examples of austenitic stainless steels that can be used to form the stainless steel foil include SUS304, SUS301, and SUS316L, with SUS304 being particularly preferred.

[0058] In the case of a metal foil, the thickness of the barrier layer 3 should be such that it at least functions as a barrier layer that prevents moisture penetration, and is, for example, about 9 to 200 μm. The upper limit of the thickness of the barrier layer 3 is preferably about 85 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, and particularly preferably about 35 μm or less, and the lower limit is preferably about 10 μm or more, even more preferably about 20 μm or more, and more preferably about 25 μm or more. Preferred ranges for the thickness include about 10 to 85 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 35 μm, about 20 to 85 μm, about 20 to 50 μm, about 20 to 40 μm, about 20 to 35 μm, about 25 to 85 μm, about 25 to 50 μm, about 25 to 40 μm, and about 25 to 35 μm. When the barrier layer 3 is made of an aluminum alloy foil, the above-mentioned ranges are particularly preferred, with about 25 to 50 μm and about 25 to 40 μm being particularly preferred. Furthermore, particularly when the barrier layer 3 is made of a stainless steel foil, the upper limit of the thickness of the stainless steel foil is preferably about 60 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, even more preferably about 30 μm or less, and particularly preferably about 25 μm or less, and the lower limit is preferably about 10 μm or more, more preferably about 15 μm or more. Preferred thickness ranges include about 10 to 60 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 30 μm, about 10 to 25 μm, about 15 to 60 μm, about 15 to 50 μm, about 15 to 40 μm, about 15 to 30 μm, and about 15 to 25 μm.

[0059] [Corrosion-resistant coating 3a, 3b] The packaging material for an electricity storage device of the present disclosure is provided with a corrosion-resistant coating on at least one surface of the barrier layer 3. The packaging material for an electricity storage device of the present disclosure may be provided with the corrosion-resistant coating 3a only on the surface of the barrier layer 3 facing the heat-sealable resin layer 4, or may be provided with the corrosion-resistant coatings 3a and 3b on both surfaces of the barrier layer 3, respectively.

[0060] In the exterior material for an electricity storage device according to the present disclosure, when the corrosion-resistant coating 3a was analyzed using time-of-flight secondary ion mass spectrometry, it was found that the corrosion-resistant coating 3a was composed of CrPO4 - The peak intensity P derived from CrPO4 PO3 for - The peak intensity P derived from PO3 The ratio P PO3 / CrPO4 is in the range of 6 to 120. When the peak intensity ratio is in this specific range and the peak height ratio P OCO / C-C is in the range of 0.10 or more and 0.50 or less, and furthermore, a compound (curing agent) having an isocyanate group is used to form the adhesive layer 5 in contact with the corrosion-resistant coating, so that even if moisture penetrates into the inside of the electricity storage device, the adhesive layer has excellent adhesion to the barrier layer having the corrosion-resistant coating.

[0061] In addition, in the present disclosure, when the corrosion-resistant coating was analyzed using time-of-flight secondary ion mass spectrometry, it was found that CrPO4 - The peak intensity P derived from CrPO4 PO2 - The peak intensity P derived from PO2 The ratio P PO2 / CrPO4 is preferably in the range of 7 to 70.

[0062] In the present disclosure, when the corrosion-resistant coatings 3a and 3b are provided on both sides of the barrier layer 3, the peak intensity ratio P PO3 / CrPO4 , preferably P PO2 / CrPO4 The peak intensity ratio P PO3 / CrPO4 , preferably P PO2 / CrPO4 In particular, the adhesion between the corrosion-resistant coating located on the adhesive layer side of the barrier layer and the adjacent adhesive layer 5 is likely to decrease due to penetration of an electrolytic solution containing moisture, and therefore, in the packaging material for an electricity storage device of the present disclosure, the corrosion-resistant coating 3a is provided on at least the surface of the barrier layer 3 on the heat-sealable resin layer 4 side.

[0063] In this disclosure, CrPO4 - The peak intensity P derived from CrPO4 PO3 for - The peak intensity P derived from PO3 The ratio P PO3 / CrPO4 The ratio P may be in the range of 6 to 120. PO3 / CrPO4 The lower limit of the ratio P is about 10 or more, and the upper limit is preferably about 115 or less, more preferably about 110 or less, and even more preferably about 50 or less. PO3 / CrPO4 Preferred ranges include about 6 to 115, about 6 to 110, about 6 to 50, about 10 to 120, about 10 to 115, about 10 to 110, about 10 to 50, and about 20 to 32, and among these, about 10 to 50, and more preferably about 20 to 32, are particularly preferred.

[0064] Also, CrPO4 - The peak intensity P derived from CrPO4 PO2 - The peak intensity P derived from PO2 The ratio P PO2 / CrPO4 is preferably in the range of 7 to 70, and from the viewpoint of further improving the adhesion, the ratio P PO2 / CrPO4 The lower limit is preferably about 10 or more, and the upper limit is preferably about 65 or less, more preferably about 50 or less. PO2 / CrPO4 Preferred ranges include about 7 to 70, about 7 to 65, about 7 to 50, about 10 to 70, about 10 to 65, about 10 to 50, and about 18 to 37, and among these, about 10 to 50, and more preferably about 18 to 37, are particularly preferred.

[0065] Specifically, the method of analyzing the corrosion-resistant films 3a and 3b using time-of-flight secondary ion mass spectrometry can be carried out using a time-of-flight secondary ion mass spectrometer under the following measurement conditions.

[0066] (Measurement conditions) Primary ion: Bismuth cluster doubly charged ion (Bi3 ++ ) Primary ion accelerating voltage: 30 kV Mass range (m / z): 0~1500 Measurement range: 100 μm x 100 μm Number of scans: 16 scans / cycle Number of pixels (per side): 256 pixels Etching ions: Ar gas cluster ion beam (Ar-GCIB) Etching ion acceleration voltage: 5.0 kV

[0067] Furthermore, in the exterior material for an electricity storage device according to the present disclosure, analysis of the corrosion-resistant coating 3a by X-ray photoelectron spectroscopy (XPS) revealed a peak P derived from an O-C=O bond in the range of 287 eV to 290 eV. OCO and a peak P at 285 eV due to C-C bonds. C-C is detected, and peak P OCO The height of the peak P C-C The peak height ratio P is obtained by dividing OCO / C-C is in the range of 0.10 to 0.50. OCO / C-C is within such a specific range, the peak intensity ratio is within such a specific range, and the peak intensity P PO3 The ratio P PO3 / CrPO4 is in the range of 6 to 120, and furthermore, a compound (curing agent) having an isocyanate group is used to form the adhesive layer 5 in contact with the corrosion-resistant coating, so that even if moisture penetrates into the interior of the electricity storage device, the adhesive layer and the barrier layer having the corrosion-resistant coating are excellent in adhesion. Because the packaging material for an electricity storage device of the present disclosure has high adhesion between the corrosion-resistant coating 3a and the adhesive layer 5, it can exhibit high peel strength and excellent adhesion even when a peel test is conducted under harsh conditions, for example, as measured in the examples, in which a test piece is immersed in an electrolyte solution containing moisture and placed at high temperatures.

[0068] From the viewpoint of further improving the adhesion between the corrosion-resistant coating 3a and the adhesive layer 5 (and further between the corrosion-resistant coating 3b and the layer adjacent thereto, which will be described later), the peak height ratio P OCO / C-CThe lower limit of the peak height ratio P is preferably about 0.10, more preferably 0.15, and the upper limit thereof is preferably about 0.50. OCO / C-C The preferred range of is 0.10 to 0.50, more preferably about 0.15 to 0.50, and particularly preferably about 0.20 to 0.30.

[0069] In the packaging material for an electricity storage device of the present disclosure, from the viewpoint of further enhancing the adhesion between the corrosion-resistant coating 3a and the adhesive layer 5 (and further between the corrosion-resistant coating 3b and an adjacent layer, which will be described later), a peak P derived from the Cr2p3 / 2 of a chromium compound is detected in the range of 576 eV to 581 eV by XPS analysis of the corrosion-resistant coating 3a. Cr It is preferable to detect a peak corresponding to the peak. The detection of this peak confirms that a chromium compound is contained in the composition for forming the corrosion-resistant coating 3a by chemical conversion treatment. Cr atoms play a central role in the coating, being coordinated by groups such as -COOH, -NH, and -CN. This allows them to form crosslinked structures with functional groups that have structures that can serve as other ligands, such as polycarboxylic acids and their ammonium salts, thereby imparting durability, such as corrosion resistance and chemical resistance.

[0070] From the same viewpoint, in the exterior material for an electricity storage device of the present disclosure, analysis of the corrosion-resistant coating 3a by X-ray photoelectron spectroscopy revealed a peak P2p derived from the phosphate compound in the range of 132 eV to 135 eV. P It is preferable to detect the peak P P By detecting this, it can be confirmed that phosphoric acid or its salt is contained in the composition for forming the corrosion-resistant coating 3a by chemical conversion treatment. Phosphoric acid is known to etch metal surfaces during chemical conversion treatment to form highly durable coatings, such as phosphate compound coatings, on the metal surfaces. Furthermore, in the presence of metal atoms with a high coordination number, such as Cr, phosphoric acid is also incorporated into the above-mentioned coordinate crosslinked structure, which is thought to contribute to the adhesion between the metal surface and the highly durable coating.

[0071] From the same viewpoint, in the exterior packaging material for an electricity storage device according to the present disclosure, it is preferable that a peak derived from F1s of the fluorine compound is detected in the range of 685 eV to 689 eV by XPS analysis of the corrosion-resistant coating 3a. F By detecting this, it can be confirmed that a fluorine compound is contained in the composition for forming the corrosion-resistant coating 3a by chemical conversion treatment. When the barrier layer is an aluminum alloy, the fluorine atoms bond with the aluminum alloy to form an aluminum fluoride coating, which is more durable than an aluminum oxide coating.

[0072] Furthermore, from the same viewpoint, in the packaging material for an electricity storage device of the second disclosure, the peak P Cr , peak P P , peak P F At least peak P Cr is preferably detected, and peak P Cr In addition, peak P P and peak P F It is more preferable that at least one of the peaks P Cr , peak P P , and peak P F It is particularly preferred that all of the following be detected:

[0073] In the packaging material for an electricity storage device of the present disclosure, the above-mentioned various peaks detected by XPS analysis (i.e., the value of the peak height ratio P OCO / C-C , and furthermore, the peak P originating from chromium compounds Cr , peak P originating from phosphate compounds P , and peak P due to fluorine compounds FThe barrier layer 3 may be provided with a corrosion-resistant coating 3a having at least one of the peaks, and further, a corrosion-resistant coating 3b having the various peaks may be provided on the surface of the barrier layer 3 facing the substrate layer 1. The provision of the corrosion-resistant coating 3b can also improve adhesion between the corrosion-resistant coating 3b on the surface of the barrier layer 3 and a layer in contact therewith (for example, the adhesive layer 2), which has the effect of preventing delamination between the substrate layer 1 and the barrier layer 3 when exposed to high-temperature and high-humidity conditions, for example.

[0074] Specifically, the corrosion-resistant coatings 3a and 3b can be analyzed using XPS using an X-ray photoelectron spectroscopy analyzer under the following measurement conditions: JIS K0162:2010 can be used as a reference for the measurement conditions for X-ray photoelectron spectroscopy.

[0075] (Measurement conditions) Incident X-ray: Mg Kα (non-monochromatic X-ray, hν=1253.6eV) X-ray output: 10kV 20mA (200W) Photoelectron capture angle: 90 degrees (input lens positioned normal to the sample) Measurement area: 6mmφ Peak shift correction: Correction was made so that the binding energy at which the peak intensity of the C1s peak becomes maximum is 285 eV.

[0076] When analyzing the peak position (binding energy) of a corrosion-resistant coating laminated on an exterior material for an electrical storage device using XPS, first, the layer (thermally adhesive resin layer, adhesive layer, etc.) laminated on the barrier layer on the side to be analyzed is physically peeled off. This physical peeling is performed without using water, organic solvents, acidic or alkaline aqueous solutions, etc. After peeling between the barrier layer and adhesive layer, if the adhesive layer remains on the surface of the barrier layer, it is removed by etching with Ar-GCIB. The corrosion-resistant coating on the surface of the barrier layer obtained in this way is analyzed using XPS. Furthermore, if the layer laminated on the barrier layer on the side to be analyzed is an adhesive layer, each layer is similarly physically peeled off and etched away for analysis.

[0077] The presence or absence of the above peaks can be easily confirmed as detected peaks displayed on the monitor screen of the X-ray photoelectron spectrometer if the peak is clear. However, if the peak is small and unclear, it can be judged based on the area, half-width, and the presence or absence of peaks related to the same atom. Specifically, the judgment is made by performing the following procedures. First, (1) after background subtraction by the Shirley method and curve fitting, if it can be determined from the peak area that the component is contained in an amount of 0.1% or more, the peak is judged to be present. Further, as supplementary means, the following criteria are used for judgment: (2) the half-width of the peak that appears after fitting is greater than the energy resolution of the instrument, and (3) in addition to the main peak, peaks resulting from photoelectrons in outer shell orbitals of the main peak are also confirmed. Note that X-ray photoelectron spectrometers usually come with analysis software; in the examples, "Vision Processing" by Kratos, the instrument manufacturer, was used.

[0078] The corrosion-resistant films 3a and 3b can be formed by chemically treating the surface of the barrier layer 3. The peak height ratio P OCO / C-C , and furthermore, the peak P originating from chromium compounds Cr , peak P originating from phosphate compounds P , and peak P due to fluorine compounds F From the viewpoint of suitably forming a corrosion-resistant coating having at least one of the above, the corrosion-resistant coatings 3a, 3b are preferably formed from a composition containing at least an acrylic resin having a COOH group, a chromium compound, and a phosphate compound. More specifically, the corrosion-resistant coatings 3a, 3b can be suitably formed by chemically treating the surface of the barrier layer 3 using a treatment liquid containing these components. The chemical treatment can be performed by applying the treatment liquid to the surface of the barrier layer 3 and baking it. Note that the peak intensity ratio P PO3 / CrPO4 (Furthermore, the peak intensity ratio P PO2 / CrPO4 ), and the peak height ratio value P OCO / C-Ccan be adjusted to the above range.

[0079] Peak intensity ratio P PO3 / CrPO4 (Furthermore, the peak intensity ratio P PO2 / CrPO4 ), and the peak height ratio value P OCO / C-C In order to further enhance the adhesion between the corrosion-resistant coating 3a and the adhesive layer 5 (and between the corrosion-resistant coating 3b and an adjacent layer) with the above range, the acrylic resin is preferably polyacrylic acid, an acrylic acid methacrylic acid ester copolymer, an acrylic acid maleic acid copolymer, an acrylic acid styrene copolymer, or a derivative thereof such as a sodium salt, an ammonium salt, or an amine salt. Derivatives of polyacrylic acid, such as the ammonium salt, sodium salt, or amine salt of polyacrylic acid, are particularly preferred. In the present disclosure, polyacrylic acid refers to a polymer of acrylic acid. The acrylic resin is also preferably a copolymer of acrylic acid and a dicarboxylic acid or a dicarboxylic acid anhydride, or an ammonium salt, sodium salt, or amine salt of a copolymer of acrylic acid and a dicarboxylic acid or a dicarboxylic acid anhydride. Only one type of acrylic resin may be used, or two or more types may be mixed together.

[0080] From the same viewpoint, the weight-average molecular weight of the acrylic resin is preferably about 1,000 to 1,000,000, more preferably about 3,000 to 800,000, and even more preferably about 10,000 to 800,000. The higher the molecular weight, the higher the durability, but the water solubility of the acrylic resin decreases, making the coating liquid unstable and resulting in a lack of manufacturing stability. Conversely, the lower the molecular weight, the lower the durability. In the present disclosure, when the weight-average molecular weight of the acrylic resin is 1,000 or more, durability is high, and when it is 1,000,000 or less, manufacturing stability is good. In the present disclosure, the weight-average molecular weight of the acrylic resin is a value measured by gel permeation chromatography (GPC) under conditions using polystyrene as a standard sample.

[0081] Furthermore, the acid value of an acrylic resin is preferably high because it is believed that the more COOH groups there are, the greater the effect of contributing to adhesion. However, when the resin is in the form of a salt as described above, the acid value may not be able to reflect the amount of O-C=O bonds. Therefore, it is believed that analyzing the O-C=O bonds from the XPS spectrum, as in the present disclosure, will better reflect adhesion.

[0082] From the same viewpoint, the chromium compound is preferably at least one of chromium (III) fluoride and chromium (III) nitrate, and more preferably chromium (III) nitrate. As described above, it is believed that a highly durable coating structure is formed by a coordination bridge structure centered on the Cr atom or aluminum fluoride.

[0083] Another method for providing a highly durable coating by providing a crosslinked structure to the corrosion-resistant coatings 3a and 3b described above is to use a crosslinking agent that reacts with COOH groups. Suitable crosslinking agents include compounds having an isocyanate group, an oxazoline group, an amino group, and an epoxy group.

[0084] Furthermore, the composition that forms the corrosion-resistant coatings 3a and 3b preferably further contains phosphoric acid. Phosphoric acid has a cleaning effect on the barrier layer surface (specifically, the effect of removing deteriorated oxide films and dirt from the barrier layer surface) and an effect of forming a crosslinked structure in the coating after baking by coordinating as phosphate ions to the barrier layer surface or metal ions such as chromium ions. Since the carboxylate ions in the corrosion-resistant coating are thought to have a similar effect, phosphoric acid is not essential. However, from the perspective of improving the cleaning effect on the barrier layer and stably mass-producing exterior materials for electricity storage devices, it is preferable to use phosphoric acid.

[0085] From the viewpoint of further enhancing the adhesion between the corrosion-resistant coating 3a and the adhesive layer 5 (and further between the corrosion-resistant coating 3b and an adjacent layer), particularly preferred compositions for the composition (treatment liquid) that forms the corrosion-resistant coatings 3a, 3b include a composition containing polyacrylic acid, chromium (III) nitrate, and phosphoric acid, a composition containing polyacrylic acid and chromium (III) nitrate, a composition containing an acrylic acid methacrylic acid ester copolymer, chromium (III) nitrate, and phosphoric acid, a composition containing a sodium salt of an acrylic acid maleic acid copolymer, chromium (III) nitrate, and phosphoric acid, a composition containing an acrylic acid styrene copolymer, chromium (III) nitrate, and phosphoric acid, and a composition containing various salts of polyacrylic acid (sodium salt, ammonium salt, amine salt, etc.), chromium (III) nitrate, and phosphoric acid.

[0086] The ratio of the chromium compound to phosphoric acid and / or its salt in the treatment solution is not particularly limited, but it is preferable that the peak intensity ratio P PO3 / CrPO4 , and even P PO2 / CrPO4 From the viewpoint of setting each of these within the above ranges, the ratio of phosphoric acid and / or its salt to 100 parts by mass of the chromium compound is preferably about 30 to 120 parts by mass, more preferably about 40 to 110 parts by mass. As the phosphoric acid and its salt, for example, condensed phosphoric acid and its salt can also be used.

[0087] The solid concentration of the treatment solution that forms the corrosion-resistant film is determined by applying and baking the treatment solution to the barrier layer, and the peak intensity ratio P PO3 / CrPO4 (Furthermore, the peak intensity ratio P PO2 / CrPO4 ), the peak height ratio value P OCO / C-C , and furthermore, the peak P originating from chromium compounds Cr , peak P originating from phosphate compounds P , and peak P due to fluorine compounds F There are no particular limitations as long as a corrosion-resistant coating having at least one of the above is formed, but the content may be, for example, about 1 to 10 mass %.

[0088] The thickness of the corrosion-resistant coatings 3a, 3b is not particularly limited, but from the viewpoint of effectively increasing the adhesion between the corrosion-resistant coating 3a and the adhesive layer 5 (and further between the corrosion-resistant coating 3b and an adjacent layer), the thickness is preferably about 1 nm to 10 μm, more preferably about 1 to 100 nm, and even more preferably about 1 to 50 nm. The thickness of the corrosion-resistant coating can be measured by observation with a transmission electron microscope, or by a combination of observation with a transmission electron microscope and energy dispersive X-ray spectroscopy or electron energy loss spectroscopy.

[0089] From the same viewpoint, the surface 1 m of the barrier layer 3 2 The amount of Cr in the corrosion-resistant films 3a and 3b per unit mass is preferably about 0.5 to 30%, more preferably about 1 to 20%, and even more preferably about 3 to 10%.

[0090] Examples of methods for applying the composition for forming the corrosion-resistant films 3a and 3b to the surface of the barrier layer 3 include bar coating, roll coating, gravure coating, and dipping.

[0091] Peak intensity ratio P PO3 / CrPO4 (Furthermore, the peak intensity ratio P PO2 / CrPO4 ), and the peak height ratio value P OCO / C-C In order to set the temperature in the above-mentioned range and improve the adhesion between the corrosion-resistant coating 3a and the adhesive layer 5 (and further between the corrosion-resistant coating 3b and the layer adjacent thereto), the heating temperature when baking the treatment liquid to form the corrosion-resistant coating is preferably about 120 to 210° C., more preferably about 130 to 190° C. From the same viewpoint, the baking time is preferably about 1 to 30 seconds, more preferably about 5 to 10 seconds.

[0092] From the viewpoint of more efficiently performing the chemical conversion treatment on the surface of the barrier layer 3, it is preferable to perform a degreasing treatment using a known treatment method such as an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or an acid activation method before providing a corrosion-resistant coating on the surface of the barrier layer 3.

[0093] [Thermofusible resin layer 4] In the packaging material for an electricity storage device of the present disclosure, the heat-sealable resin layer 4 corresponds to the innermost layer and is a layer (sealant layer) that functions to seal the electricity storage device elements by heat-sealing the heat-sealable resin layers together when the electricity storage device is assembled.

[0094] The resin constituting the heat-sealable resin layer 4 is not particularly limited as long as it is heat-sealable, but resins containing a polyolefin skeleton, such as polyolefin and acid-modified polyolefin, are preferred. The presence of a polyolefin skeleton in the resin constituting the heat-sealable resin layer 4 can be determined by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like. Furthermore, when the resin constituting the heat-sealable resin layer 4 is analyzed by infrared spectroscopy, a peak derived from maleic anhydride is preferably detected. For example, when maleic anhydride-modified polyolefin is measured by infrared spectroscopy, a peak derived from maleic anhydride is detected at a wavenumber of 1760 cm. -1 Near and wave number 1780cm -1 A peak derived from maleic anhydride is detected around . When the thermally adhesive resin layer 4 is a layer made of maleic anhydride-modified polyolefin, a peak derived from maleic anhydride is detected when measured by infrared spectroscopy. However, if the degree of acid modification is low, the peak becomes small and may not be detected. In such cases, analysis can be performed by nuclear magnetic resonance spectroscopy.

[0095] Specific examples of polyolefins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; polypropylenes such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymers of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymers of propylene and ethylene); propylene-α-olefin copolymers; and ethylene-butene-propylene terpolymers. Among these, polypropylene is preferred. When the polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer. These polyolefin resins may be used alone or in combination of two or more.

[0096] The polyolefin may also be a cyclic polyolefin. Cyclic polyolefins are copolymers of olefins and cyclic monomers, and examples of olefins constituting the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. Examples of cyclic monomers constituting the cyclic polyolefin include cyclic alkenes such as norbornene; and cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these, preferred are cyclic alkenes, and more preferred are norbornene.

[0097] Acid-modified polyolefins are polymers modified by block polymerization or graft polymerization of polyolefins with an acid component. Examples of acid-modified polyolefins include the above-mentioned polyolefins, copolymers of the above-mentioned polyolefins with polar molecules such as acrylic acid or methacrylic acid, and crosslinked polyolefins. Examples of acid components used for acid modification include carboxylic acids or anhydrides thereof, such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride.

[0098] The acid-modified polyolefin may be an acid-modified cyclic polyolefin. The acid-modified cyclic polyolefin is a polymer obtained by copolymerizing a part of the monomers constituting the cyclic polyolefin by replacing it with an acid component, or by block polymerizing or graft polymerizing an acid component onto the cyclic polyolefin. The acid-modified cyclic polyolefin is the same as described above. The acid component used for the acid modification is the same as the acid component used for the modification of the polyolefin.

[0099] Preferred acid-modified polyolefins include polyolefins modified with carboxylic acid or its anhydride, polypropylenes modified with carboxylic acid or its anhydride, maleic anhydride-modified polyolefins, and maleic anhydride-modified polypropylenes.

[0100] The thermally adhesive resin layer 4 may be formed of one type of resin alone or may be formed of a blend polymer of two or more types of resins. Furthermore, the thermally adhesive resin layer 4 may be formed of only one layer, or may be formed of two or more layers of the same or different resins.

[0101] Furthermore, the heat-sealable resin layer 4 may contain a lubricant, etc., as necessary. When the heat-sealable resin layer 4 contains a lubricant, the moldability of the electrical storage device packaging material can be improved. The lubricant is not particularly limited, and known lubricants can be used. The lubricants may be used alone or in combination of two or more.

[0102] The lubricant is not particularly limited, but preferably an amide-based lubricant is used. Specific examples of the lubricant include those exemplified for the base layer 1. The lubricant may be used alone or in combination of two or more.

[0103] When a lubricant is present on the surface of the heat-sealable resin layer 4, the amount of the lubricant present is not particularly limited, but from the viewpoint of improving the formability of the packaging material for an electricity storage device, it is preferably 10 to 50 mg / m 2about 15 to 40 mg / m 2 The degree of

[0104] The lubricant present on the surface of the heat-sealable resin layer 4 may be a lubricant exuded from the resin constituting the heat-sealable resin layer 4, or a lubricant applied to the surface of the heat-sealable resin layer 4.

[0105] The thickness of the heat-sealable resin layer 4 is not particularly limited as long as it can heat-seal the heat-sealable resin layers to each other and function to seal the electricity storage device element, but may be, for example, about 100 μm or less, preferably about 85 μm or less, and more preferably about 15 to 85 μm. For example, when the thickness of the adhesive layer 5 described below is 10 μm or more, the thickness of the heat-sealable resin layer 4 is preferably about 85 μm or less, and more preferably about 15 to 45 μm. For example, when the thickness of the adhesive layer 5 described below is less than 10 μm or when the adhesive layer 5 is not provided, the thickness of the heat-sealable resin layer 4 is preferably about 20 μm or more, and more preferably about 35 to 85 μm.

[0106] [Adhesive layer 5] In the packaging material for an electricity storage device according to the present disclosure, the adhesive layer 5 is a layer provided between the corrosion-resistant coating 3a of the barrier layer 3 and the heat-sealable resin layer 4 in order to firmly bond them together. The adhesive layer 5 is provided so as to be in contact with the corrosion-resistant coating provided on the surface of the barrier layer 3.

[0107] The adhesive layer 5 is formed from a resin that can bond the corrosion-resistant coating 3a of the barrier layer 3 and the heat-sealable resin layer 4, and in the packaging material for an electricity storage device of the present disclosure, the adhesive layer 5 is composed of a cured product of a resin composition that includes a compound having an isocyanate group.

[0108] The resin contained in the resin composition used to form the adhesive layer 5 preferably contains a polyolefin skeleton, and examples thereof include the polyolefins and acid-modified polyolefins exemplified for the heat-sealable resin layer 4 described above. The presence of a polyolefin skeleton in the resin of the adhesive layer 5 can be determined by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like, and no particular analytical method is required. Furthermore, when the resin constituting the adhesive layer 5 is analyzed by infrared spectroscopy, a peak derived from maleic anhydride is preferably detected. For example, when maleic anhydride-modified polyolefin is measured by infrared spectroscopy, a peak derived from maleic anhydride is detected at a wavenumber of 1760 cm. -1 Near and wave number 1780cm -1 A peak derived from maleic anhydride is detected around this point. However, if the degree of acid modification is low, the peak may be small and not be detected. In this case, analysis can be performed using nuclear magnetic resonance spectroscopy.

[0109] The compound having an isocyanate group is not particularly limited, but from the viewpoint of effectively improving the adhesion between the corrosion-resistant coating 3a and the adhesive layer 5, a polyfunctional isocyanate compound is preferably used. The polyfunctional isocyanate compound is not particularly limited as long as it has two or more isocyanate groups. Specific examples of polyfunctional isocyanate curing agents include pentane diisocyanate (PDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymers or nurates thereof, mixtures of these, and copolymers with other polymers. Other examples include adducts, biuret compounds, and isocyanurates.

[0110] The content of the compound having an isocyanate group in the adhesive layer 5 is preferably in the range of 0.1 to 50 mass %, and more preferably in the range of 0.5 to 40 mass %, in the resin composition constituting the adhesive layer 5. This effectively improves the adhesion between the barrier layer 3 and the adhesive layer 5. Furthermore, the content of the compound having an isocyanate group in the resin composition constituting the adhesive layer 5 is preferably about 0.5 to 6 mass parts, and more preferably about 1 to 5 mass parts, per 100 mass parts of the resin.

[0111] From the viewpoint of further enhancing the adhesion between the corrosion-resistant coating 3a and the adhesive layer 5, the adhesive layer 5 preferably contains an acid-modified polyolefin in addition to the compound having an isocyanate group. Particularly preferred examples of the acid-modified polyolefin include polyolefins modified with carboxylic acid or its anhydride, polypropylenes modified with carboxylic acid or its anhydride, maleic anhydride-modified polyolefins, and maleic anhydride-modified polypropylenes.

[0112] Furthermore, the adhesive layer 5 may further contain, as a curing agent, other curing agents such as a compound having an epoxy group or a compound having an oxazoline group in addition to the compound having an isocyanate group. If unreacted substances of the curing agent such as the compound having an isocyanate group, the compound having an epoxy group, or the compound having an oxazoline group remain in the adhesive layer 5, the presence of the unreacted substances can be confirmed by a method selected from, for example, infrared spectroscopy, Raman spectroscopy, time-of-flight secondary ion mass spectrometry (TOF-SIMS), etc.

[0113] The content of the compound having an isocyanate group in the adhesive layer 5 is preferably in the range of 0.1 to 50 mass %, and more preferably in the range of 0.5 to 40 mass %, of the resin composition constituting the adhesive layer 5. This can effectively improve the adhesion between the barrier layer 3 and the adhesive layer 5.

[0114] An example of a compound having an epoxy group is an epoxy resin. The epoxy resin is not particularly limited as long as it is a resin capable of forming a crosslinked structure by the epoxy groups present in the molecule, and known epoxy resins can be used. The weight-average molecular weight of the epoxy resin is preferably about 50 to 2,000, more preferably about 100 to 1,000, and even more preferably about 200 to 800. In the present disclosure, the weight-average molecular weight of the epoxy resin is a value measured by gel permeation chromatography (GPC) under conditions using polystyrene as a standard sample.

[0115] Specific examples of epoxy resins include glycidyl ether derivatives of trimethylolpropane, bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolac glycidyl ether, glycerin polyglycidyl ether, polyglycerin polyglycidyl ether, etc. One type of epoxy resin may be used alone, or two or more types may be used in combination.

[0116] When a compound having an epoxy group is blended in addition to a compound having an isocyanate group as a curing agent for the adhesive layer 5, the amount of the compound having an epoxy group is approximately 20 to 200 parts by mass per 100 parts by mass of the compound having an isocyanate group.

[0117] The compound having an oxazoline group is not particularly limited as long as it is a compound having an oxazoline skeleton. Specific examples of the compound having an oxazoline group include those having a polystyrene main chain and those having an acrylic main chain. Examples of commercially available products include the Epocross series manufactured by Nippon Shokubai Co., Ltd.

[0118] When a compound having an oxazoline group is blended in addition to a compound having an isocyanate group as a curing agent for the adhesive layer 5, the amount of the compound having an oxazoline group is approximately 20 to 200 parts by mass per 100 parts by mass of the compound having an isocyanate group.

[0119] The thickness of the adhesive layer 5 is preferably about 10 μm or less, more preferably about 5 μm or less, and is also preferably about 1 μm or more, more preferably 2 μm or more, and the thickness range is preferably about 1 to 10 μm, about 1 to 5 μm, about 2 to 10 μm, or about 2 to 5 μm. The adhesive layer 5 can be formed by applying a resin composition that forms the adhesive layer 5 and curing it by heating or the like.

[0120] [Surface coating layer 6] The packaging material for an electricity storage device according to the present disclosure may have a surface coating layer 6 on the substrate layer 1 (the side of the substrate layer 1 opposite to the barrier layer 3) as needed, for the purpose of improving at least one of design, electrolyte resistance, scratch resistance, formability, etc. The surface coating layer 6 is a layer located on the outermost layer side of the packaging material for an electricity storage device when an electricity storage device is assembled using the packaging material for an electricity storage device.

[0121] The surface coating layer 6 can be formed from a resin such as polyvinylidene chloride, polyester, polyurethane, acrylic resin, or epoxy resin.

[0122] When the resin forming the surface coating layer 6 is a curable resin, the resin may be either a one-component curable resin or a two-component curable resin, but is preferably a two-component curable resin. Examples of two-component curable resins include two-component curable polyurethane, two-component curable polyester, and two-component curable epoxy resin. Among these, two-component curable polyurethane is preferred.

[0123] Examples of two-component curing polyurethanes include polyurethanes containing a base agent containing a polyol compound and a curing agent containing an isocyanate compound. Preferred examples include two-component curing polyurethanes that use a polyol such as polyester polyol, polyether polyol, or acrylic polyol as the base agent and an aromatic or aliphatic polyisocyanate as the curing agent. Furthermore, it is preferable to use a polyester polyol that has hydroxyl groups on the side chain in addition to the terminal hydroxyl groups of the repeating unit as the polyol compound. Forming the surface coating layer 6 from polyurethane provides the electrical storage device exterior material with excellent electrolyte resistance.

[0124] The surface coating layer 6 may contain additives such as the aforementioned lubricants, antiblocking agents, matting agents, flame retardants, antioxidants, tackifiers, and antistatic agents, at least on the surface and / or inside of the surface coating layer 6, as needed, depending on the functionality to be imparted to the surface of the surface coating layer 6. Examples of additives include fine particles with an average particle size of approximately 0.5 nm to 5 μm. The average particle size of the additive is the median size measured with a laser diffraction / scattering particle size distribution analyzer.

[0125] The additive may be either inorganic or organic. The shape of the additive is not particularly limited, and examples thereof include spherical, fibrous, plate-like, amorphous, and scaly shapes.

[0126] Specific examples of additives include talc, silica, graphite, kaolin, montmorillonite, mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, carbon black, carbon nanotubes, high-melting-point nylon, acrylate resin, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, and nickel. The additives may be used alone or in combination of two or more. Among these additives, silica, barium sulfate, and titanium oxide are preferred from the viewpoints of dispersion stability, cost, and the like. The additives may also be subjected to various surface treatments, such as insulation treatment and high-dispersibility treatment.

[0127] The method for forming the surface coating layer 6 is not particularly limited, and examples thereof include a method of applying a resin to form the surface coating layer 6. When an additive is blended into the surface coating layer 6, a resin mixed with the additive may be applied.

[0128] The thickness of the surface coating layer 6 is not particularly limited as long as the surface coating layer 6 exhibits the above-mentioned functions, and may be, for example, about 0.5 to 10 μm, and preferably about 1 to 5 μm.

[0129] 3. Manufacturing method for exterior materials for power storage devices The method for producing an electrical storage device exterior material is not particularly limited as long as it can produce a laminate in which the layers of the electrical storage device exterior material of the present disclosure are laminated, and examples thereof include a method comprising a step of laminating at least a substrate layer 1, a barrier layer 3, an adhesive layer 5, and a heat-sealable resin layer 4 in this order. That is, the method for producing an electrical storage device exterior material of the present disclosure comprises a step of laminating at least a substrate layer, a barrier layer, an adhesive layer, and a heat-sealable resin layer in this order to produce a laminate, the adhesive layer being a cured product of a resin composition containing a compound having an isocyanate group, the barrier layer having a corrosion-resistant coating on at least the surface on the adhesive layer side, and the corrosion-resistant coating having a composition of CrPO4 - The peak intensity P derived from CrPO4 PO3 for - The peak intensity P derived from PO3 The ratio P PO3 / CrPO4 is in the range of 6 or more and 120 or less, and when the corrosion-resistant coating is analyzed by X-ray photoelectron spectroscopy, a peak P OCO and a peak P at 285 eV due to C1s of the C-C bond. C-C is detected, and the peak P OCO The height of the peak P C-C The peak height ratio P is obtained by dividing OCO / C-C is in the range of 0.10 to 0.50.

[0130] An example of a method for manufacturing an exterior material for an electricity storage device according to the present disclosure is as follows: First, a laminate (hereinafter, sometimes referred to as "laminate A") is formed in which a base layer 1, an adhesive layer 2, and a barrier layer 3 are laminated in this order. Specifically, laminate A can be formed by a dry lamination method in which an adhesive used to form adhesive layer 2 is applied to base layer 1 or to barrier layer 3, the surface of which has been chemically treated as necessary, by a coating method such as gravure coating or roll coating, and then dried, followed by laminating the barrier layer 3 or base layer 1 and curing the adhesive layer 2.

[0131] Next, a heat-sealable resin layer 4 is laminated on the barrier layer 3 of the laminate A. When the heat-sealable resin layer 4 is laminated directly on the barrier layer 3, the heat-sealable resin layer 4 may be laminated on the barrier layer 3 of the laminate A by a method such as thermal lamination or extrusion lamination. When an adhesive layer 5 is provided between the barrier layer 3 and the heat-sealable resin layer 4, for example, (1) a method of laminating the adhesive layer 5 and the heat-sealable resin layer 4 by extruding them onto the barrier layer 3 of the laminate A (co-extrusion lamination, tandem lamination), (2) a method of separately forming a laminate in which the adhesive layer 5 and the heat-sealable resin layer 4 are laminated, and laminating this on the barrier layer 3 of the laminate A by a thermal lamination, or a method of forming a laminate in which the adhesive layer 5 is laminated on the barrier layer 3 of the laminate A, and laminating this on the heat-sealable resin layer 4 by a thermal lamination. (3) a method (sandwich lamination method) in which a molten adhesive layer 5 is poured between the barrier layer 3 of the laminate A and a heat-sealable resin layer 4 previously formed into a sheet, and the laminate A and the heat-sealable resin layer 4 are bonded together via the adhesive layer 5; (4) a method in which an adhesive for forming the adhesive layer 5 is solution-coated on the barrier layer 3 of the laminate A, followed by drying or baking, and then the heat-sealable resin layer 4 previously formed into a sheet is laminated on the adhesive layer 5.

[0132] When the surface coating layer 6 is provided, the surface coating layer 6 is laminated on the surface of the base material layer 1 opposite to the barrier layer 3. The surface coating layer 6 can be formed, for example, by applying the above-mentioned resin for forming the surface coating layer 6 to the surface of the base material layer 1. The order of the step of laminating the barrier layer 3 on the surface of the base material layer 1 and the step of laminating the surface coating layer 6 on the surface of the base material layer 1 is not particularly limited. For example, after the surface coating layer 6 is formed on the surface of the base material layer 1, the barrier layer 3 may be formed on the surface of the base material layer 1 opposite to the surface coating layer 6.

[0133] As described above, a laminate is formed which includes the optional surface coating layer 6, the base material layer 1, the optional adhesive layer 2, the barrier layer 3, the adhesive layer 5, and the heat-sealable resin layer 4 in this order. In order to strengthen the adhesiveness of the optional adhesive layer 2, the laminate may be further subjected to a heat treatment.

[0134] In the packaging material for an electricity storage device, each layer constituting the laminate may be subjected to a surface activation treatment such as corona treatment, blast treatment, oxidation treatment, ozone treatment, etc., as needed to improve processability. For example, by subjecting the surface of the base layer 1 opposite to the barrier layer 3 to corona treatment, the printability of ink on the surface of the base layer 1 can be improved.

[0135] 4. Applications of exterior materials for energy storage devices The electrical storage device packaging material of the present disclosure is used in a package for hermetically housing an electrical storage device element such as a positive electrode, a negative electrode, and an electrolyte. That is, an electrical storage device can be formed by housing an electrical storage device element including at least a positive electrode, a negative electrode, and an electrolyte in a package formed from the electrical storage device packaging material of the present disclosure. Note that, in the electrical storage device packaging material of the present disclosure, the peak intensity and the like can be analyzed by cutting the electrical storage device packaging material from the electrical storage device. When cutting the electrical storage device packaging material from the electrical storage device, a sample is obtained from a portion of the electrical storage device where the heat-sealable resin layers are not heat-sealed to each other, such as the top or bottom surface, and is used for analysis.

[0136] Specifically, an electricity storage device using the electricity storage device packaging material is provided by covering an electricity storage device element having at least a positive electrode, a negative electrode, and an electrolyte with the electricity storage device packaging material of the present disclosure in a state in which metal terminals connected to each of the positive electrode and negative electrode protrude outward, so that a flange portion (a region where the heat-sealable resin layers contact each other) can be formed around the periphery of the electricity storage device element, and the heat-sealable resin layers of the flange portion are heat-sealed to form a hermetic seal. Note that when an electricity storage device element is housed in a package formed from the electricity storage device packaging material of the present disclosure, the package is formed so that the heat-sealable resin portion of the electricity storage device packaging material of the present disclosure faces inside (the surface that contacts the electricity storage device element).

[0137] The electrical storage device packaging material of the present disclosure may be used for either a primary electrical storage device or a secondary electrical storage device, but is preferably used for a secondary electrical storage device. The type of secondary electrical storage device to which the electrical storage device packaging material of the present disclosure is applied is not particularly limited, and examples include lithium ion electrical storage devices, lithium ion polymer electrical storage devices, lead acid batteries, nickel-metal hydride batteries, nickel-cadmium batteries, nickel-iron batteries, nickel-zinc batteries, silver oxide-zinc batteries, metal-air electrical storage devices, polyvalent cation electrical storage devices, condensers, and capacitors. Among these secondary electrical storage devices, lithium ion electrical storage devices and lithium ion polymer electrical storage devices are suitable applications for the electrical storage device packaging material of the present disclosure.

[0138] In the electrical storage device packaging material of the present disclosure, the barrier layer provided with the corrosion-resistant coating can maintain adhesion for a long period of time, making the electrical storage device packaging material of the present disclosure particularly useful as a packaging material for large electrical storage devices used in vehicles such as hybrid cars and electric cars. [Example]

[0139] The present disclosure will be described in detail below with reference to examples and comparative examples, but the present disclosure is not limited to the examples.

[0140] <Manufacturing of exterior materials for energy storage devices> Example 1 A biaxially oriented nylon film (25 μm) serving as a substrate layer was subjected to chemical conversion treatment on both sides using the method described below, and a barrier layer composed of aluminum alloy foil (JIS H4160:1994 A8021H-O, 40 μm thick) with a corrosion-resistant coating (30 nm thick) was then laminated by dry lamination. Specifically, a two-component urethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one side of the aluminum alloy foil with the corrosion-resistant coating to form an adhesive layer (3 μm thick). Next, the adhesive layer on the barrier layer with the corrosion-resistant coating and the biaxially oriented nylon film side of the substrate layer were laminated, and then aging treatment was performed to produce a laminate of biaxially oriented nylon film / adhesive layer / barrier layer with corrosion-resistant coatings on both sides.

[0141] Next, the barrier layer side of the laminate was laminated to a heat-sealable resin layer via an adhesive layer by dry lamination. Specifically, a resin composition containing maleic anhydride-modified polypropylene (molecular weight 70,000) and an isocyanate-based curing agent (HDI) in a mass ratio of 100:3 was applied to the barrier layer side surface of the laminate (the surface of the corrosion-resistant coating) so that the thickness after curing was 2 μm, and then dried. Next, a random polypropylene film (thickness 40 μm) was laminated as a heat-sealable resin layer, and the resulting laminate was further aged to obtain an exterior material for an electricity storage device, in which a substrate layer (25 μm), an adhesive layer (3 μm), a barrier layer (40 μm) with corrosion-resistant coatings (30 nm) on both sides, an adhesive layer (2 μm), and a heat-sealable resin layer (40 μm) were laminated in this order.

[0142] The corrosion-resistant coating was formed on the surface of the barrier layer as follows: A treatment solution containing 2 parts by mass of acrylic resin (polyacrylic acid (molecular weight 10,000, acid value 778)), 2 parts by mass of chromium nitrate, and 2 parts by mass of phosphoric acid per 100 parts by mass of water was prepared, and the treatment solution was applied to both sides of the barrier layer (to a film thickness of 30 nm after drying), followed by heating and drying for approximately 3 seconds at a temperature that brought the surface temperature of the barrier layer to approximately 190°C.

[0143] Example 2 In Example 1, an outer casing material for a storage battery device was obtained in the same manner as in Example 1, except that in Example 1, the adhesive layer was formed using a resin composition containing maleic anhydride-modified polypropylene (molecular weight 150,000) and an isocyanate-based curing agent (HDI) in a mass ratio of 100:3. The outer casing material was made of a base material layer (25 μm), an adhesive layer (3 μm), a barrier layer (40 μm) with corrosion-resistant coatings (30 nm) on both sides, an adhesive layer (2 μm), and a heat-sealable resin layer (40 μm) laminated in this order.

[0144] Example 3 In Example 1, except that the molecular weight of the maleic anhydride-modified polypropylene contained in the resin composition constituting the adhesive layer was set to 110,000, an exterior material for a storage battery device was obtained in the same manner as in Example 1, in which a substrate layer (25 μm) / adhesive layer (3 μm) / barrier layer (40 μm) with corrosion-resistant coatings (30 nm) on both sides / adhesive layer (2 μm) / thermally adhesive resin layer (40 μm) were laminated in this order.

[0145] Example 4 In Example 1, an outer casing material for a power storage device was obtained in the same manner as in Example 1, except that in Example 1, the adhesive layer was formed using a resin composition containing 100 parts by mass of maleic anhydride-modified polypropylene (molecular weight 70,000), 1.5 parts by mass of an isocyanate-based curing agent (HDI), and 1.5 parts by mass of an epoxy-based curing agent. The outer casing material was made of a base material layer (25 μm), an adhesive layer (3 μm), a barrier layer (40 μm) with a corrosion-resistant coating (30 nm) on both sides (2 μm), an adhesive layer (2 μm), and a heat-sealable resin layer (40 μm) laminated in this order.

[0146] Example 5 In Example 1, an outer casing material for a power storage device was obtained in the same manner as in Example 1, except that in Example 1, the adhesive layer was formed using a resin composition containing 100 parts by mass of maleic anhydride-modified polypropylene (molecular weight 110,000), 3 parts by mass of an isocyanate-based curing agent (HDI), and 3 parts by mass of an epoxy-based curing agent. The outer casing material was formed in the same manner as in Example 1, except that the adhesive layer was formed using a resin composition containing 100 parts by mass of maleic anhydride-modified polypropylene (molecular weight 110,000), 3 parts by mass of an isocyanate-based curing agent (HDI), and 3 parts by mass of an epoxy-based curing agent. The outer casing material was formed in the same manner as in Example 1,

[0147] Example 6 An exterior material for a power storage device was obtained in the same manner as in Example 1, except that it was heated and dried for about 120 seconds at a temperature such that the surface temperature of the barrier layer reached about 190°C, and the laminate was made of a base material layer (25 μm), an adhesive layer (3 μm), a barrier layer (40 μm) with corrosion-resistant coatings (30 nm) on both sides, an adhesive layer (2 μm), and a heat-sealable resin layer (40 μm) laminated in this order.

[0148] Comparative Example 1 In Example 1, an outer casing material for a storage battery device was obtained in the same manner as in Example 1, except that in Example 1, the adhesive layer was formed using a resin composition containing 100 parts by mass of maleic anhydride-modified polypropylene (molecular weight 110,000) and 6 parts by mass of an epoxy-based curing agent (bisphenol A diglycidyl ether). The outer casing material was made of a base material layer (25 μm), an adhesive layer (3 μm), a barrier layer (40 μm) with corrosion-resistant coatings (30 nm) on both sides (40 μm), an adhesive layer (2 μm), and a heat-sealable resin layer (40 μm) laminated in this order.

[0149] Comparative Example 2 In Example 1, a packaging material for an electricity storage device was obtained in the same manner as in Example 1, except that a treatment liquid containing 43 parts by mass of aminated phenol polymer, 16 parts by mass of chromium fluoride, and 13 parts by mass of phosphoric acid was used as the treatment liquid used to form a corrosion-resistant coating on the surface of the barrier layer, in which a substrate layer (25 μm) / adhesive layer (3 μm) / barrier layer (40 μm) with corrosion-resistant coatings (30 nm) on both sides thereof / adhesive layer (2 μm) / thermally adhesive resin layer (40 μm) were laminated in this order.

[0150] Comparative Example 3 In Comparative Example 2, an outer casing material for a power storage device was obtained in the same manner as in Comparative Example 2, except that in Comparative Example 2, an adhesive layer was formed using a resin composition containing 100 parts by mass of maleic anhydride-modified polypropylene (molecular weight 70,000) and 2 parts by mass of an epoxy-based curing agent. The outer casing material was laminated in the following order: base layer (25 μm), adhesive layer (3 μm), barrier layer (40 μm) with corrosion-resistant coatings (30 nm) on both sides (40 μm), adhesive layer (2 μm), and heat-sealable resin layer (40 μm).

[0151] Comparative Example 4 In Example 1, a treatment liquid (containing water as a solvent and with a solids concentration of approximately 10% by mass) containing 20 parts by mass of an inorganic phosphorus compound (sodium phosphate) per 100 parts by mass of cerium oxide was prepared as the treatment liquid used to form the corrosion-resistant coating on the surface of the barrier layer. The treatment liquid was applied to both sides of the barrier layer (to a film thickness of 20 nm after drying), and the coating was dried by heating at a temperature such that the surface temperature of the barrier layer reached approximately 190 to 230°C for approximately 3 to 6 seconds to form a corrosion-resistant coating on the surface of the barrier layer. An exterior packaging material for an electricity storage device was obtained in the same manner as in Example 1, in which a base layer (25 μm), an adhesive layer (3 μm), a barrier layer (40 μm) with corrosion-resistant coatings (30 nm) on both sides thereof, an adhesive layer (2 μm), and a heat-sealable resin layer (40 μm) were laminated in this order.

[0152] Comparative Example 5 In Example 1, an exterior material for an electricity storage device was obtained in the same manner as in Example 1, except that the corrosion-resistant coating on the surface of the barrier layer was formed using a treatment liquid containing 2 parts by mass of an acrylic resin (polyacrylic acid (molecular weight 10,000, acid value 10)), 2 parts by mass of chromium nitrate, and 2 parts by mass of phosphoric acid per 100 parts by mass of water. The exterior material was made of a base material layer (25 μm), an adhesive layer (3 μm), a barrier layer (40 μm) with corrosion-resistant coatings (30 nm) on both sides, an adhesive layer (2 μm), and a heat-sealable resin layer (40 μm) laminated in this order.

[0153] Comparative Example 6 In Example 1, an exterior material for an electricity storage device was obtained in the same manner as in Example 1, except that the corrosion-resistant coating on the surface of the barrier layer was formed using a treatment liquid containing 2 parts by mass of an acrylic resin (polyacrylic acid (molecular weight 10,000, acid value 2,200)), 2 parts by mass of chromium nitrate, and 2 parts by mass of phosphoric acid per 100 parts by mass of water. The exterior material was made of a base material layer (25 μm), an adhesive layer (3 μm), a barrier layer (40 μm) with corrosion-resistant coatings (30 nm) on both sides, an adhesive layer (2 μm), and a heat-sealable resin layer (40 μm) laminated in this order.

[0154] Comparative Example 7 In Example 1, an exterior material for an electricity storage device was obtained in the same manner as in Example 1, except that the corrosion-resistant coating on the surface of the barrier layer was formed using a treatment liquid containing 2 parts by mass of an acrylic resin (polyacrylic acid (molecular weight 10,000, acid value 778)), 2 parts by mass of chromium nitrate, and 0.04 parts by mass of phosphoric acid per 100 parts by mass of water. The exterior material was made of a base material layer (25 μm), an adhesive layer (3 μm), a barrier layer (40 μm) with corrosion-resistant coatings (30 nm) on both sides thereof, an adhesive layer (2 μm), and a heat-sealable resin layer (40 μm) laminated in this order.

[0155] Comparative Example 8 In Example 1, an exterior material for an electricity storage device was obtained in the same manner as in Example 1, except that the corrosion-resistant coating on the surface of the barrier layer was formed using a treatment liquid containing 2 parts by mass of an acrylic resin (polyacrylic acid (molecular weight 10,000, acid value 778)), 2 parts by mass of chromium nitrate, and 21 parts by mass of phosphoric acid per 100 parts by mass of water. The exterior material was made of a base material layer (25 μm), an adhesive layer (3 μm), a barrier layer (40 μm) with corrosion-resistant coatings (30 nm) on both sides thereof, an adhesive layer (2 μm), and a heat-sealable resin layer (40 μm) laminated in this order.

[0156] <Time-of-flight secondary ion mass spectrometry> The corrosion-resistant coating was analyzed as follows. First, the barrier layer and adhesive layer were peeled off. This was done physically, without using water, organic solvents, or aqueous solutions of acids or alkalis. After the barrier layer and adhesive layer were peeled off, the adhesive layer remained on the surface of the barrier layer, so this was removed by etching with Ar-GCIB. The surface of the barrier layer thus obtained was analyzed for the corrosion-resistant coating using time-of-flight secondary ion mass spectrometry. CrPO4 - , PO2 - , and PO3 - The peak intensity P derived from CrPO4 , P PO2 , P PO3 , and peak intensity P CrPO4 Peak intensity P PO2 The ratio P PO2 / CrPO4 and peak intensity P CrPO4 Peak intensity P PO3 The ratio P PO3 / CrPO4 are shown in Table 1. In Comparative Example 4, a cerium compound was used in the chemical conversion treatment solution, but no chromium compound was used. Therefore, in Table 1, CrPO4 - Peak intensity P CrPO4 Items related to this are indicated with "-".

[0157] The details of the measurement device and measurement conditions for time-of-flight secondary ion mass spectrometry are as follows. Measurement equipment: ION-TOF time-of-flight secondary ion mass spectrometer TOF.SIMS5 (Measurement conditions) Primary ion: Bismuth cluster doubly charged ion (Bi3 ++ ) Primary ion accelerating voltage: 30 kV Mass range (m / z): 0~1500 Measurement range: 100 μm x 100 μm Number of scans: 16 scans / cycle Number of pixels (per side): 256 pixels Etching ions: Ar gas cluster ion beam (Ar-GCIB) Etching ion acceleration voltage: 5.0 kV

[0158] <Analysis by X-ray photoelectron spectroscopy (XPS)> Analysis of the corrosion-resistant film by XPS was carried out as follows. First, the barrier layer and the adhesive layer were peeled off. At this time, physical peeling was performed without using water, organic solvents, aqueous solutions of acids or alkalis, etc. After peeling between the barrier layer and the adhesive layer, since the adhesive layer remained on the surface of the barrier layer, the remaining adhesive layer was removed by etching with Ar-GCIB. Regarding the surface of the barrier layer thus obtained, analysis of the corrosion-resistant film was performed using XPS, and the following peaks were observed. Peak P OCO The height of C-C The peak height ratio value P obtained by dividing by the height of OCO / C-C , and further, the presence or absence of peaks derived from chromium compounds and peaks derived from phosphate compounds are shown in Table 1.

[0159] These peaks were identified based on the following information. P C-C : Peak derived from C1s of C-C bond at 285 eV. As described in the measurement conditions, the entire XPS data was corrected so that the maximum intensity of this peak was 285 eV. P OCO : Peak derived from C1s of O-C=O bond in the range of 287 eV to 290 eV P Cr : Peak derived from Cr2p3 / 2 of chromium compound in the range of 576 eV to 581 eV P P : Peak derived from P2p of phosphate compound in the range of 132 eV to 135 eV

[0160] Details of the X-ray photoelectron spectroscopy measurement apparatus and measurement conditions are as follows. Measurement apparatus: "ESCA-3400" manufactured by Shimadzu Corporation (manufactured by Kratos, UK) Incident X-ray: Mg Kα (non-monochromatic X-ray, hν = 1253.6 eV) X-ray output: 10 kV·20 mA (200 W) Photoelectron capture angle: 90 degrees (input lens positioned normal to the sample) Measurement area: 6mmφ Peak shift correction: Correction was made so that the binding energy at which the peak intensity of the C1s peak becomes maximum is 285 eV.

[0161] <Evaluation of Adhesion> The adhesion between the barrier layer and the heat-sealable resin layer when a moisture-containing electrolyte solution adhered to the exterior material for an electricity storage device was evaluated by measuring the peel strength (N / 15 mm) using the following method.

[0162] First, each of the exterior materials for power storage devices obtained above was cut into a size of 15 mm (TD: transverse direction, horizontal direction) and 100 mm (MD: machine direction, vertical direction), and the heat-sealing resin layer and the barrier layer of the test piece were peeled off by about 10 mm to obtain a test piece. The test piece was placed in a glass bottle, and lithium hexafluorophosphate (concentration in solution: 1 × 10) was added to a solution containing water (ethylene carbonate: diethyl carbonate: dimethyl carbonate = 1:1:1 volume ratio). 3 mol / m 3 ), water concentration 1000 ppm) was placed in the glass bottle so that the entire test piece was immersed in the electrolyte. In this state, the glass bottle was capped and sealed. The sealed glass bottle was placed in an oven set at 85°C and left to stand for 24 hours. Next, the glass bottle was removed from the oven, and the test piece was removed from the glass bottle and washed with water, and then the test piece was immersed in a container filled with water.

[0163] Next, the heat-sealable resin layer and the barrier layer of the test specimen were peeled off, and the adhesive layer and barrier layer of the test specimen were pulled in a 180° direction at a rate of 50 mm / min using a tensile tester (Shimadzu Corporation, product name AG-XPlus) with a gauge length of 50 mm. The peel strength (N / 15 mm) of the test specimen was measured. The peel strength of the test specimen was measured within 10 minutes after the test specimen was removed from the glass bottle and washed with water while its surface was still wet. The strength measured when the gauge length reached 65 mm was defined as the "peel strength immediately after removal." Furthermore, after removing the test specimen from the glass bottle and washing it with water, the test specimen was left immersed in a container containing water for 3 hours. The swelling of the heat-sealable resin layer (due to the penetration of the electrolyte) had disappeared due to the dissolution of the electrolyte in the water. The peel strength was measured in the same manner and defined as the "peel strength after 3 hours." The results are shown in Table 1.

[0164] Meanwhile, initial adhesion was evaluated as follows. First, each of the electrical storage device packaging materials obtained above was cut into a size of 15 mm (TD) and 100 mm (MD) to prepare test specimens. Next, the thermally adhesive resin layer and the barrier layer of the test specimen were peeled from each other, and the thermally adhesive resin layer and the barrier layer were pulled in a 180° direction at a rate of 50 mm / min with a gauge length of 50 mm using a tensile tester (manufactured by Shimadzu Corporation under the trade name AG-XPlus). The peel strength (N / 15 mm) of the test specimen was measured, and the strength when the gauge length reached 65 mm was defined as the initial adhesion. The results are shown in Table 1. The peel strength at the initial adhesion was defined as 100%, and the retention rate of each peel strength at the adhesion after immersion in the electrolyte solution is also shown in Table 1. Note that when the thermally adhesive resin layer and the barrier layer were peeled from each other, the adhesive layer located between these layers was laminated to either or both of the thermally adhesive resin layer and the barrier layer.

[0165] [Table 1]

[0166] The electrical storage device packaging materials of Examples 1 to 6 are composed of a laminate including at least a substrate layer, a barrier layer, an adhesive layer, and a heat-sealable resin layer in this order, and the adhesive layer is a cured product of a resin composition containing a compound having an isocyanate group. Furthermore, a corrosion-resistant coating is provided on at least the surface of the barrier layer facing the adhesive layer, and when the corrosion-resistant coating is analyzed using time-of-flight secondary ion mass spectrometry, it is found that the corrosion-resistant coating is composed of CrPO4 - The peak intensity P derived from CrPO4 PO3 for - The peak intensity P derived from PO3 The ratio P PO3 / CrPO4 is in the range of 6 to 120, and the analysis of the corrosion-resistant coating by X-ray photoelectron spectroscopy shows that the peak P OCO and a peak P at 285 eV due to C1s of the C-C bond. C-C is detected, and the peak P OCO The height of the peak P C-C The peak height ratio P is obtained by dividing OCO / C-C is in the range of 0.10 or more and 0.50 or less. As is clear from the results shown in Table 1, the electrical storage device packaging materials of Examples 1 to 6, in which the corrosion-resistant coating and adhesive layer had these characteristics, had excellent adhesion between the barrier layer provided with the corrosion-resistant coating and the adhesive layer, even when immersed in an electrolytic solution containing moisture.

[0167] As described above, the present disclosure provides the following aspects of the invention. Item 1. The device is composed of a laminate including at least a base layer, a barrier layer, an adhesive layer, and a heat-sealable resin layer in this order, the adhesive layer is a cured product of a resin composition containing a compound having an isocyanate group, a corrosion-resistant coating is provided on at least the adhesive layer side of the barrier layer; When the corrosion-resistant coating was analyzed using time-of-flight secondary ion mass spectrometry, it was found that CrPO4 - The peak intensity P derived from CrPO4 PO3 for - The peak intensity P derived from PO3The ratio P PO3 / CrPO4 is in the range of 6 to 120, Analysis of the corrosion-resistant coating by X-ray photoelectron spectroscopy revealed a peak P attributed to C1s of the O-C=O bond in the range of 287 eV to 290 eV. OCO and a peak P at 285 eV due to C1s of the C-C bond. C-C is detected, The peak P OCO The height of the peak P C-C The peak height ratio P is obtained by dividing OCO / C-C is in the range of 0.10 or more and 0.50 or less. Item 2. The packaging material for an electricity storage device according to Item 1, wherein analysis of the corrosion-resistant coating by X-ray photoelectron spectroscopy detects a peak derived from the Cr2p3 / 2 chromium compound in the range of 576 eV to 581 eV. Item 3. The packaging material for an electricity storage device according to Item 1 or 2, wherein a peak derived from P2p of a phosphate compound is detected in the range of 132 eV to 135 eV by X-ray photoelectron spectroscopy analysis of the corrosion-resistant coating. Item 4. The packaging material for an electricity storage device according to any one of Items 1 to 3, wherein a peak derived from F1s of a fluorine compound is detected in the range of 685 eV to 689 eV by analysis of the corrosion-resistant coating by X-ray photoelectron spectroscopy. Item 5. The packaging material for an electricity storage device according to any one of Items 1 to 4, wherein the corrosion-resistant coating is formed from a composition containing at least an acrylic resin having a COOH group, a chromium compound, and a phosphate compound. Item 6. The exterior packaging material for an electricity storage device according to Item 5, wherein the acrylic resin is at least one selected from the group consisting of polyacrylic acid, ammonium salts of polyacrylic acid, sodium salts of polyacrylic acid, and amine salts of polyacrylic acid. Item 7. The exterior packaging material for an electricity storage device according to Item 5, wherein the acrylic resin is at least one selected from the group consisting of a copolymer of acrylic acid and a dicarboxylic acid or a dicarboxylic acid anhydride, an ammonium salt of the copolymer, a sodium salt of the copolymer, and an amine salt of the copolymer. Item 8. The packaging material for an electricity storage device according to any one of Items 5 to 7, wherein the chromium compound is at least one of chromium (III) fluoride and chromium (III) nitrate. Item 9. The packaging material for an electricity storage device according to any one of Items 1 to 8, wherein the resin contained in the resin composition constituting the adhesive layer has a polyolefin skeleton. Item 10. The packaging material for an electricity storage device according to any one of Items 1 to 9, wherein the adhesive layer contains an acid-modified polyolefin. Item 11. The packaging material for an electricity storage device according to any one of Items 1 to 10, wherein a peak derived from maleic anhydride is detected when the adhesive layer is analyzed by infrared spectroscopy. Item 12. The acid-modified polyolefin of the adhesive layer is maleic anhydride-modified polypropylene, Item 11. The packaging material for a power storage device according to Item 10, wherein the heat-sealable resin layer contains polypropylene. Item 13. The method includes a step of laminating at least a base layer, a barrier layer, an adhesive layer, and a heat-sealable resin layer in this order to obtain a laminate, the adhesive layer is a cured product of a resin composition containing a compound having an isocyanate group, a corrosion-resistant coating is provided on at least the adhesive layer side of the barrier layer; When the corrosion-resistant coating was analyzed using time-of-flight secondary ion mass spectrometry, it was found that CrPO4 - The peak intensity P derived from CrPO4 PO3 for - The peak intensity P derived from PO3 The ratio P PO3 / CrPO4 is in the range of 6 to 120, Analysis of the corrosion-resistant coating by X-ray photoelectron spectroscopy revealed a peak P attributed to C1s of the O-C=O bond in the range of 287 eV to 290 eV. OCO and a peak P at 285 eV due to C1s of the C-C bond. C-C is detected, The peak P OCO The height of the peak P C-C The peak height ratio P is obtained by dividing OCO / C-Cis in the range of 0.10 or more and 0.50 or less. Item 14. An electricity storage device, in which an electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed from the exterior packaging material for an electricity storage device according to any one of Items 1 to 12. [Explanation of symbols]

[0168] 1...Base material layer 2...Adhesive layer 3...Barrier layer 3a,3b…Corrosion-resistant film 4…Thermofusible resin layer 5...adhesive layer 6…Surface coating layer 10...Exterior materials for energy storage devices

Claims

1. The laminate is composed of at least a surface coating layer, a base material layer, a black adhesive layer, a barrier layer, an adhesive layer, and a heat-sealable resin layer, in this order; the adhesive layer is a cured product of a resin composition containing a compound having an isocyanate group, a corrosion-resistant coating is provided on at least the adhesive layer side of the barrier layer; When the corrosion-resistant coating was analyzed using time-of-flight secondary ion mass spectrometry, it was found that CrPO 4 - The peak intensity P CrPO4 PO for 3 - The peak intensity P PO3 The ratio P PO3 / CrPO4 is in the range of 6 to 120, Analysis of the corrosion-resistant coating by X-ray photoelectron spectroscopy revealed a peak P attributed to C1s of the O—C═O bond in the range of 287 eV to 290 eV. OCO and a peak P at 285 eV due to C1s of the C-C bond. C-C is detected, The peak P OCO The height of the peak P C-C The peak height ratio P obtained by dividing OCO / C-C is in the range of 0.10 or more and 0.50 or less.

2. The laminate is composed of at least a base layer, a barrier layer, an adhesive layer, and a heat-sealable resin layer in this order, the substrate layer includes a polyester film and a polyamide film, the adhesive layer is a cured product of a resin composition containing a compound having an isocyanate group, a corrosion-resistant coating is provided on at least the adhesive layer side of the barrier layer; When the corrosion-resistant coating was analyzed using time-of-flight secondary ion mass spectrometry, it was found that CrPO 4 - The peak intensity P CrPO4 PO for 3 - The peak intensity P PO3 The ratio P PO3 / CrPO4 is in the range of 6 to 120, Analysis of the corrosion-resistant coating by X-ray photoelectron spectroscopy revealed a peak P attributed to C1s of the O—C═O bond in the range of 287 eV to 290 eV. OCO and a peak P at 285 eV due to C1s of the C-C bond. C-C is detected, The peak P OCO The height of the peak P C-C The peak height ratio P obtained by dividing OCO / C-C is in the range of 0.10 or more and 0.50 or less.

3. The laminate is composed of at least a substrate layer, a barrier layer, a layer formed of a cured product of a resin composition containing a compound having an isocyanate group, and a heat-fusible resin layer, in this order; the substrate layer includes a polyester film and a polyamide film, a corrosion-resistant coating is provided on a surface of the barrier layer on the side of a layer formed of a cured product of a resin composition containing a compound having an isocyanate group, When the corrosion-resistant coating was analyzed using time-of-flight secondary ion mass spectrometry, it was found that CrPO 4 - The peak intensity P CrPO4 PO for 3 - The peak intensity P PO3 The ratio P PO3 / CrPO4 is in the range of 6 to 120, Analysis of the corrosion-resistant coating by X-ray photoelectron spectroscopy revealed a peak P attributed to C1s of the O—C═O bond in the range of 287 eV to 290 eV. OCO and a peak P at 285 eV due to C1s of the C-C bond. C-C is detected, The peak P OCO The height of the peak P C-C The peak height ratio P obtained by dividing OCO / C-C is in the range of 0.10 or more and 0.50 or less.

4. 4. The electrical storage device packaging material according to claim 1, wherein a peak derived from Cr2p3 / 2 of a chromium compound is detected in the range of 576 eV to 581 eV by analysis of the corrosion-resistant coating by X-ray photoelectron spectroscopy.

5. 5. The electrical storage device packaging material according to claim 1, wherein a peak derived from P2p of a phosphate compound is detected in a range of 132 eV to 135 eV by analysis of the corrosion-resistant coating by X-ray photoelectron spectroscopy.

6. 6. The electrical storage device packaging material according to any one of claims 1 to 5, wherein a peak derived from F1s of a fluorine compound is detected in a range of 685 eV to 689 eV by analysis of the corrosion-resistant coating by X-ray photoelectron spectroscopy.

7. The corrosion-resistant coating is formed from a composition containing at least an acrylic resin having a COOH group, a chromium compound, and a phosphate compound. The exterior material for an electricity storage device according to any one of claims 1 to 6.

8. 8. The exterior packaging material for an electricity storage device according to claim 7, wherein the acrylic resin is at least one selected from the group consisting of polyacrylic acid, an ammonium salt of polyacrylic acid, a sodium salt of polyacrylic acid, and an amine salt of polyacrylic acid.

9. 8. The exterior material for an electricity storage device according to claim 7, wherein the acrylic resin is at least one selected from the group consisting of a copolymer of acrylic acid and a dicarboxylic acid or a dicarboxylic acid anhydride, an ammonium salt of the copolymer, a sodium salt of the copolymer, and an amine salt of the copolymer.

10. The packaging material for an electricity storage device according to any one of claims 7 to 9, wherein the chromium compound is at least one of chromium (III) fluoride and chromium (III) nitrate.

11. The packaging material for an electricity storage device according to claim 1 or 2, wherein a resin contained in a resin composition constituting the adhesive layer has a polyolefin skeleton.

12. The packaging material for an electricity storage device according to claim 1 or 2, wherein the adhesive layer contains an acid-modified polyolefin.

13. The packaging material for an electricity storage device according to claim 1 or 2, wherein when the adhesive layer is analyzed by infrared spectroscopy, a peak derived from maleic anhydride is detected.

14. the acid-modified polyolefin of the adhesive layer is maleic anhydride-modified polypropylene, The packaging material for an electricity storage device according to claim 12 , wherein the heat-sealable resin layer contains polypropylene.

15. The method includes a step of laminating at least a surface coating layer, a base layer, a black adhesive layer, a barrier layer, an adhesive layer, and a heat-sealable resin layer in this order to obtain a laminate, the adhesive layer is a cured product of a resin composition containing a compound having an isocyanate group, a corrosion-resistant coating is provided on at least the adhesive layer side of the barrier layer; When the corrosion-resistant coating was analyzed using time-of-flight secondary ion mass spectrometry, it was found that CrPO 4 - The peak intensity P CrPO4 PO for 3 - The peak intensity P PO3 The ratio P PO3 / CrPO4 is in the range of 6 to 120, Analysis of the corrosion-resistant coating by X-ray photoelectron spectroscopy revealed a peak P attributed to C1s of the O—C═O bond in the range of 287 eV to 290 eV. OCO and a peak P at 285 eV due to C1s of the C-C bond. C-C is detected, The peak P OCO The height of the peak P C-C The peak height ratio P obtained by dividing OCO / C-C is in the range of 0.10 or more and 0.50 or less.

16. An electricity storage device, wherein an electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed from the exterior packaging material for an electricity storage device according to any one of claims 1 to 14.

Images