JPWO2020153459A1 - Exterior materials for power storage devices, manufacturing methods for exterior materials for power storage devices, and power storage devices - Google Patents

Abstract

Provided is an exterior material for a power storage device, which maintains high adhesion of a barrier layer having a corrosion-resistant film even when an electrolytic solution adheres, and has excellent moldability. It is composed of a laminate having at least a first base material layer, a first adhesive layer, a second base material layer, a second adhesive layer, a barrier layer, and a heat-sealing resin layer in this order, and is composed of the barrier. A corrosion-resistant film is provided on the surface of at least one side of the layer, and when the corrosion-resistant film is analyzed using a time-of-flight secondary ion mass spectrometry method, the peak intensity derived from CrPO4- An exterior material for a power storage device in which the ratio PPO3 / CrPO4 of the peak intensity PPO3 derived from PO3- to PCrPO4 is in the range of 6 to 120.

Description

The present disclosure relates to an exterior material for a power storage device, a method for manufacturing an exterior material for a power storage device, and a power storage device.

Conventionally, various types of power storage devices have been developed. In these power storage devices, the power storage device element composed of electrodes, electrolytes, etc. needs to be sealed with an exterior material or the like. As the exterior material for the power storage device, a metal exterior material is often used.

In recent years, as the performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones and the like has improved, storage devices having various shapes have been demanded. Further, the power storage device is also required to be thinner and lighter. However, it is difficult to keep up with the diversification of the shapes of power storage devices with the metal exterior materials that have been widely used in the past. Moreover, since it is made of metal, there is a limit to the weight reduction of the exterior material.

Therefore, as an exterior material for a power storage device that can be easily processed into various shapes and can be made thinner and lighter, a film-like laminate in which a base material layer / barrier layer / heat-sealing resin layer is sequentially laminated. Has been proposed (see, for example, Patent Document 1).

In such a film-shaped exterior material for a power storage device, a recess is generally formed by molding, and a storage device element such as an electrode or an electrolytic solution is arranged in the space formed by the recess to have heat fusion property. By heat-sealing the resin layers to each other, a power storage device in which the power storage device element is housed inside the exterior material for the power storage device can be obtained.

Japanese Unexamined Patent Publication No. 2008-287971

When water enters the inside of a power storage device, the water may react with an electrolyte or the like to generate an acidic substance. For example, the electrolytic solution used in a lithium ion storage device or the like contains a fluorine compound (LiPF ₆ , LiBF _4, etc.) as an electrolyte, and when the fluorine compound reacts with water, hydrogen fluoride is generated. It is known.

The barrier layer of the exterior material for a power storage device formed of a film-shaped laminate is usually composed of a metal foil or the like, and has a problem that it is easily corroded when an acid comes into contact with the barrier layer. As a technique for improving the corrosion resistance of such exterior materials for power storage devices, a technique using a barrier layer having a corrosion resistant film formed on the surface by chemical conversion treatment is known.

Conventionally, as a chemical conversion treatment for forming a corrosion-resistant film, various methods such as chromate treatment using a chromium compound such as chromium oxide and phosphoric acid treatment using a phosphoric acid compound are known.

However, as the inventors of the present disclosure have repeatedly studied, the conventional barrier layer provided with the corrosion-resistant film has adhesion (that is, corrosion resistance) to the layer adjacent to the layer provided with the corrosion-resistant film. It was clarified that the adhesion between the film and the layer in contact with the film was insufficient. More specifically, if the electrolytic solution adheres to the exterior material for a power storage device, it may not be possible to maintain high adhesion between the corrosion-resistant film and the layer in contact with the film.

Further, as described above, since the exterior material for a power storage device is used for molding, high moldability is required.

Under such circumstances, the present disclosure provides an exterior material for a power storage device, which maintains high adhesion of a barrier layer provided with a corrosion-resistant film even when an electrolytic solution adheres, and has excellent moldability. The main purpose is that. Further, it is also an object of the present disclosure to provide a method for manufacturing an exterior material for a power storage device and a power storage device using the exterior material for the power storage device.

The inventors of the present disclosure have made diligent studies to solve the above-mentioned problems. As a result, it is composed of a laminate having at least a first base material layer, a first adhesive layer, a second base material layer, a second adhesive layer, a barrier layer, and a heat-sealing resin layer in this order. , on at least one side surface of the barrier layer is provided with a corrosion resistant coating, for the corrosion-resistant coating, when analyzed using time-of-flight secondary ion mass spectrometry, CrPO ₄ ^- to PO ₃ for derived peak intensity P _CrPO4 ^- the ratio P _{PO3 / CrPO4} from the peak intensity P _PO3 is, the outer package is for a power storage device within range of 6 or more 120 or less, corrosion resistant coating on the surface of the barrier layer It has been found that, in spite of the above, high adhesion is maintained even when the electrolytic solution adheres, and further excellent moldability is provided.
The present disclosure is an invention completed by further studies based on these findings.

That is, the present disclosure provides the inventions of the following aspects.
It is composed of a laminate having at least a first base material layer, a first adhesive layer, a second base material layer, a second adhesive layer, a barrier layer, and a heat-sealing resin layer in this order.
A corrosion-resistant film is provided on the surface of at least one side of the barrier layer.
For the corrosion resistant coating, flight when analyzed with time-of secondary ion mass spectrometry, CrPO ₄ ^- PO ₃ to the peak intensity P _CrPO4 derived from ^- the ratio of the peak intensity P _PO3 derived from P _{PO3 / An} exterior material for a power storage device in which CrPO4 is in the range of 6 or more and 120 or less.

According to the present disclosure, it is possible to provide an exterior material for a power storage device, which maintains high adhesion of a barrier layer provided with a corrosion-resistant film even when an electrolytic solution adheres, and has excellent moldability. Further, according to the present disclosure, it is also possible to provide a method for manufacturing an exterior material for a power storage device and a power storage device using the exterior material for the power storage device.

It is a schematic diagram which shows an example of the cross-sectional structure of the exterior material for a power storage device of this disclosure. It is a schematic diagram which shows an example of the cross-sectional structure of the exterior material for a power storage device of this disclosure. It is a schematic diagram which shows an example of the cross-sectional structure of the exterior material for a power storage device of this disclosure. It is a schematic diagram which shows an example of the cross-sectional structure of the exterior material for a power storage device of this disclosure.

The exterior material for a power storage device of the present disclosure includes at least a first base material layer, a first adhesive layer, a second base material layer, a second adhesive layer, a barrier layer, and a heat-sealing resin layer in this order. It is composed of a laminated body, and a corrosion-resistant film is provided on the surface of at least one side of the barrier layer, and the corrosion-resistant film is analyzed by using a time-of-flight secondary ion mass spectrometry method. case, CrPO ₄ ^- PO ₃ to the peak intensity P _CrPO4 derived from ^- the ratio of the peak intensity P _PO3 derived from P _{PO3 / CrPO4,} characterized in that in the range of 6 to 120 or less. Hereinafter, the exterior material for the power storage device of the present disclosure and the power storage device using the exterior material for the power storage device will be described in detail.

In this specification, the numerical range indicated by "~" means "greater than or equal to" and "less than or equal to". For example, the notation of 2 to 15 mm means 2 mm or more and 15 mm or less.

1. 1. Laminated structure of exterior material for power storage device As shown in FIG. 1, the exterior material for power storage device of the present disclosure has at least a first base material layer 11, a first adhesive layer 21, a second base material layer 12, and a second. It is composed of a laminate including an adhesive layer 22, a barrier layer 3, and a heat-sealing resin layer 4 in this order. In the exterior material for a power storage device of the present disclosure, the first base material layer 11 is on the outermost layer side, and the heat-sealing resin layer 4 is on the innermost layer. That is, at the time of assembling the power storage device, the heat-sealing resin layers 4 located on the peripheral edge of the power storage device element are heat-sealed to seal the power storage device element, whereby the power storage device element is sealed.

As shown in FIGS. 5 may be provided. Further, as shown in FIG. 4, a surface covering layer 6 or the like may be provided on the outside of the first base material layer 11 (the side opposite to the heat-sealing resin layer 4 side), if necessary. ..

A corrosion-resistant film is provided on the surface of at least one side of the barrier layer 3. The corrosion resistant film contains chromium. FIG. 1 shows a schematic view of the case where the exterior material for a power storage device of the present disclosure is provided with a corrosion-resistant film 3a on the surface of the barrier layer 3 on the heat-sealing resin layer 4 side. 2 to 4 show schematic views of the case where the exterior material for a power storage device of the present disclosure is provided with corrosion-resistant films 3a and 3b on both sides of the barrier layer 3, respectively. As will be described later, in the exterior material for the power storage device of the present disclosure, the corrosion resistant film 3a may be provided only on the surface of the barrier layer 3 on the heat-sealing resin layer 4 side, or the barrier layer 3 may be provided. The corrosion-resistant film 3b may be provided only on the surface of the second base material layer 12 side, or the corrosion-resistant films 3a and 3b may be provided on both sides of the barrier layer 3, respectively.

The thickness of the laminate constituting the exterior material 10 for the power storage device is not particularly limited, but the upper limit is preferably about 180 μm or less, about 155 μm or less, and about 120 μm or less from the viewpoint of cost reduction, energy density improvement, and the like. From the viewpoint of maintaining the function of the exterior material for the power storage device of protecting the power storage device element, the lower limit is preferably about 35 μm or more, about 45 μm or more, and about 60 μm or more, and the preferable range is about 60 μm or more. 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, and about 60 to 120 μm. Of these, about 60 to 180 μm is particularly preferable.

In the exterior material for a power storage device, the MD and TD of the barrier layer 3 described later can usually be discriminated from each other in the manufacturing process. For example, when the barrier layer 3 is made of an aluminum alloy foil, linear streaks, so-called rolling marks, are formed on the surface of the aluminum alloy foil in the rolling direction (RD: Rolling Direction) of the aluminum alloy foil. ing. Since the rolling marks extend along the rolling direction, the rolling direction of the aluminum alloy foil can be grasped by observing the surface of the aluminum alloy foil. Further, in the manufacturing process of the laminated body, since the MD of the laminated body and the RD of the aluminum alloy foil usually match, the surface of the aluminum alloy foil of the laminated body is observed and the rolling direction (RD) of the aluminum alloy foil is observed. By specifying the above, the MD of the laminated body can be specified. Further, since the TD of the laminated body is in the direction perpendicular to the MD of the laminated body, the TD of the laminated body can also be specified.

2. 2. Composition of each layer forming the exterior material for the power storage device [first base material layer 11 and second base material layer 12]
In the exterior material for a power storage device of the present disclosure, the first base material layer 11 and the second base material layer 12 are layers provided for the purpose of exerting a function as a base material of the exterior material for a power storage device. The first base material layer 11 is a layer located on the outermost layer side of the exterior material for a power storage device. Further, the second base material layer 12 is a layer provided between the first base material layer 11 and the barrier layer 3 via the first adhesive layer 21 described later.

The materials forming the first base material layer 11 and the second base material layer 12 are not particularly limited as long as they each have a function as a base material, that is, at least having an insulating property. Each of the first base material layer 11 and the second base material layer 12 can be formed by using, for example, a resin, and the resin may contain an additive described later.

When the first base material layer 11 and the second base material layer 12 are each made of resin, the first base material layer 11 and the second base material layer 12 are each made of, for example, a resin film made of resin. It may be present, or it may be formed by applying a resin. The resin film may be an unstretched film or a stretched film. Examples of the stretched film include a uniaxially stretched film and a biaxially stretched film, and a biaxially stretched film is preferable. Examples of the stretching method for forming the biaxially stretched film include a sequential biaxial stretching method, an inflation method, and a simultaneous biaxial stretching method. Examples of the method of applying the resin include a roll coating method, a gravure coating method, and an extrusion coating method.

Examples of the resin forming the first base material layer 11 and the second base material layer 12 include resins such as polyester, polyamide, polyolefin, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, and phenol resin, respectively. , Modified products of these resins. Further, the resin forming the first base material layer 11 and the second base material layer 12 may be a copolymer of these resins or a modified product of the copolymer, respectively. Further, it may be a mixture of these resins.

Examples of the resin forming the first base material layer 11 and the second base material layer 12 include polyester and polyamide, respectively.

Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyester. Further, examples of the copolymerized polyester include a copolymerized polyester containing ethylene terephthalate as a repeating unit as a main body. Specifically, a copolymer polyester (hereinafter abbreviated after polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / adipate), polyethylene (terephthalate / terephthalate /), which polymerizes with ethylene isophthalate using ethylene terephthalate as a repeating unit. (Sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate), polyethylene (terephthalate / decandicarboxylate) and the like can be mentioned. These polyesters may be used alone or in combination of two or more.

Specific examples of the polyamide include an aliphatic polyamide such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and a copolymer of nylon 6 and nylon 66; terephthalic acid and / or isophthalic acid. Hexamethylenediamine-isophthalic acid-terephthalic acid copolymerized polyamide such as nylon 6I, nylon 6T, nylon 6IT, nylon 6I6T (I stands for isophthalic acid, T stands for terephthalic acid), polyamide MXD6 (polymethaki Aroma-containing polyamides such as silylene adipamide); alicyclic polyamides such as polyamide PACM6 (polybis (4-aminocyclohexyl) methaneadipamide); further lactam components and isocyanate components such as 4,4'-diphenylmethane-diisocyanate. Examples thereof include a copolymerized polyamide, a polyesteramide copolymer or a polyether esteramide copolymer which is a copolymer of a copolymerized polyamide and a polyester or a polyalkylene ether glycol; and a polyamide such as these copolymers. These polyamides may be used alone or in combination of two or more.

The first base material layer 11 and the second base material layer 12 preferably contain at least one of polyamide and polyester, respectively. Further, from the viewpoint of further improving the moldability, it is more preferable that the first base material layer 11 contains at least one of polyamide and polyester, and the second base material layer 12 contains polyamide, and in particular, the first. It is preferable that the base material layer 11 and the second base material layer 12 contain polyamide, and it is more preferable that the first base material layer 11 and the second base material layer 12 are made of polyamide.

The first base material layer 11 and the second base material layer 12 preferably contain at least one of a polyester film, a polyamide film, and a polyolefin film, respectively, and the stretched polyester film, the stretched polyamide film, and the stretched polyolefin film. It is preferable to contain at least one of them, and more preferably to contain at least one of a stretched polyethylene terephthalate film, a stretched polybutylene terephthalate film, a stretched nylon film and a stretched polypropylene film, and a biaxially stretched polyethylene terephthalate film and a biaxially stretched film. It is more preferable to contain at least one of a polybutylene terephthalate film, a biaxially stretched nylon film, and a biaxially stretched polypropylene film.

Specific examples of the combination of the first base material layer 11 and the second base material layer 12 preferably include a polyester film and a nylon film, a nylon film and a nylon film, a polyester film and a polyester film, and the like, and more preferably. Examples thereof include a stretched nylon film and a stretched polyester film, a stretched nylon film and a stretched nylon film, and a stretched polyester film and a stretched polyester film. Further, in these combinations, the polyester film is preferably a polyethylene terephthalate film.

Further, on at least one of the surface and the inside of the first base material layer 11 and the second base material layer 12, a lubricant, a flame retardant, an antiblocking agent, an antioxidant, a light stabilizer, a tackifier, and an antistatic agent, respectively. Additives such as agents may be present. Only one type of additive may be used, or two or more types may be mixed and used.

In the present disclosure, from the viewpoint of improving the moldability of the exterior material for the power storage device, it is preferable that the lubricant is present on the surface of the first base material layer 11. The lubricant is not particularly limited, but an amide-based lubricant is preferable. Specific examples of the amide-based lubricant include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylol amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides. Specific examples of the saturated fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide and the like. Specific examples of unsaturated fatty acid amides include oleic acid amides and erucic acid amides. Specific examples of the substituted amide include N-oleyl palmitate amide, N-stearyl stearyl amide, N-stearyl oleic acid amide, N-oleyl stealic acid amide, N-stearyl erucate amide and the like. Further, specific examples of trimethylolamide include trimethylolstearic acid amide. Specific examples of the saturated fatty acid bisamide include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbechenic acid amide, and hexamethylene bisstea. Examples thereof include acid amides, hexamethylene bisbechenic acid amides, hexamethylene hydroxystearic acid amides, N, N'-disteallyl adipic acid amides, and N, N'-distearyl sebasic acid amides. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amides, ethylene biserukaic acid amides, hexamethylene bisoleic acid amides, N, N'-diorail adipic acid amides, and N, N'-diorail sevacinic acid amides. And so on. Specific examples of the fatty acid ester amide include stearoamide ethyl stearate and the like. Specific examples of the aromatic bisamide include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, and N, N'-distearylisophthalic acid amide. The lubricant may be used alone or in combination of two or more.

If a lubricant is present on the surface of the first base layer 11, as it is its abundance is not particularly limited, preferably about 3 mg / m ² or more, more preferably 4~15mg / m ² approximately, more preferably 5 ~ 14 mg / m ² is mentioned.

The lubricant present on the surface of the first base material layer 11 may be one obtained by exuding the lubricant contained in the resin constituting the first base material layer 11, or may be on the surface of the first base material layer 11. It may be coated with a lubricant.

In the present disclosure, the thickness of the first base material layer 11 is preferably about 10 μm or more, more preferably about 12 μm or more, and more preferably, from the viewpoint of improving the moldability while reducing the thickness of the exterior material for the power storage device. Is about 20 μm or less, more preferably about 18 μm or less, still more preferably about 15 μm or less, and preferred ranges are about 10 to 20 μm, about 10 to 18 μm, about 10 to 15 μm, about 12 to 20 μm, and 12 to 18 μm. The degree is about 12 to 15 μm. From the same viewpoint, the thickness of the second base material layer 12 is preferably about 12 μm or more, more preferably about 15 μm or more, preferably about 30 μm or less, more preferably about 28 μm or less, still more preferably. The range is about 25 μm or less, and preferred ranges include about 12 to 30 μm, about 12 to 28 μm, about 12 to 25 μm, about 15 to 30 μm, about 15 to 28 μm, and about 15 to 25 μm.

Further, from the same viewpoint, the total thickness of the first base material layer 11 and the second base material layer 12 is preferably about 20 μm or more, more preferably about 25 μm or more, still more preferably about 28 μm or more, and preferably about 28 μm or more. The range is about 50 μm or less, more preferably about 45 μm or less, still more preferably about 40 μm or less, still more preferably about 35 μm or less, and preferred ranges are about 20 to 50 μm, about 20 to 45 μm, about 20 to 40 μm, and about 20 to 20. Examples thereof include about 35 μm, about 25 to 50 μm, about 25 to 45 μm, about 25 to 40 μm, about 25 to 35 μm, about 28 to 50 μm, about 28 to 45 μm, about 28 to 40 μm, and about 28 to 35 μm.

In the exterior material for a power storage device of the present disclosure, the first base material layer 11, the first adhesive layer 21, and the first adhesive layer 21 are on the side opposite to the barrier layer 3 side (outer layer side) of the second adhesive layer 22, which will be described later. 2 In addition to the base material layer 12, another layer may be provided. The material forming the other layer is not particularly limited as long as it has an insulating property. Examples of the material forming the other layer include polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, phenol resin, polyetherimide, polyimide, and a mixture or copolymer thereof. Be done. When the other layer is provided, the thickness of the other layer is preferably about 0.1 to 20 μm, more preferably about 0.5 to 10 μm.

[First Adhesive Layer 21]
In the exterior material for a power storage device of the present disclosure, the first adhesive layer 21 is a layer provided for adhering the first base material layer 11 and the second base material layer 12.

In the exterior material for a power storage device of the present disclosure, it is preferable that the hardness of the first adhesive layer 21 and the hardness of the second adhesive layer 22, which will be described later, are 20 MPa or more, respectively. As a result, particularly excellent moldability is exhibited in the exterior material for a power storage device in which the base material layer is formed of a plurality of layers (that is, the first base material layer 11 and the second base material layer 12). More specifically, when the hardness of the first adhesive layer 21 and the second adhesive layer 22 measured by the nanoindentation method is 20 MPa or more, particularly excellent moldability is exhibited.

From the viewpoint of improving the moldability of the exterior material for the power storage device, the hardness of the first adhesive layer 21 is more preferably 30 MPa or more, further preferably 51 MPa or more, preferably 400 MPa or less, more preferably 350 MPa or less. Can be mentioned. Preferred ranges of the hardness of the first adhesive layer 21 include about 20 to 400 MPa, about 20 to 350 MPa, about 30 to 400 MPa, about 30 to 350 MPa, about 51 to 400 MPa, and about 51 to 350 MPa.

In the present disclosure, the hardness of the first adhesive layer 21 and the second adhesive layer 22 measured by the nanoindentation method is a value measured as follows, respectively. As an apparatus, a nanoindenter ((“ TriboIndenter TI950” manufactured by HYSITRON)) is used. As an indenter of the nanoindenter, a Berkovich indenter (triangular pyramid) is used. Hardness of the second adhesive layer 22 In an environment where the relative humidity is 50% and the temperature is 23 ° C., the indenter is applied to the surface of the second adhesive layer 22 of the exterior material for the power storage device (the surface where the second adhesive layer 22 is exposed, and the layers are laminated. The indenter is pushed into the adhesive layer from the surface to a load of 40 μN over 10 seconds, held in that state for 5 seconds, and then unloaded over 10 seconds. _{Using max} (μN) and the contact projection area A (μm ² ) _{at the maximum depth, the indentation hardness (MPa) is calculated by P max} / A. Further, the hardness of the first adhesive layer 21 is calculated. Is measured in the same manner as the second adhesive layer 22 except that the load is 10 μN.

The hardness of the first adhesive layer 21 is not only the type of resin contained in the adhesive, but also the molecular weight of the resin, the number of cross-linking points, the ratio of the main agent and the curing agent, the dilution ratio of the main agent and the curing agent, and the drying temperature. By adjusting the aging temperature, the aging time, and the like, the above values can be adjusted.

The adhesive used for forming the first adhesive layer 21 is not limited, but may be any of a chemical reaction type, a solvent volatile type, a heat melting type, a thermal pressure type and the like. Further, it may be a two-component curable adhesive (two-component adhesive), a one-component curable adhesive (one-component adhesive), or a resin that does not involve a curing reaction. Further, the first adhesive layer 21 may be a single layer or a multilayer.

Specific examples of the adhesive component contained in the first adhesive layer 21 include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyester; polyether; polyurethane. Epoxy resin; Phenolic resin; Polyethylene such as nylon 6, nylon 66, nylon 12, copolymerized polyamide; Polyethylene resin such as polyolefin, cyclic polyolefin, acid-modified polyolefin, acid-modified cyclic polyolefin; Polyvinyl acetate; Cellulose; (Meta ) Acrylic resin; Polyethylene; Polycarbonate; Amino resin such as urea resin and melamine resin; Rubber such as chloroprene rubber, nitrile rubber and styrene-butadiene rubber; Silicone resin and the like. These adhesive components may be used alone or in combination of two or more. Among these adhesive components, a polyurethane adhesive is preferable. In addition, the resin as an adhesive component can be used in combination with an appropriate curing agent to increase the adhesive strength. As the curing agent, an appropriate one is selected from polyisocyanate, polyfunctional epoxy resin, oxazoline group-containing polymer, polyamine resin, acid anhydride and the like, depending on the functional group of the adhesive component.

Examples of the polyurethane adhesive include a polyurethane adhesive containing a main agent containing a polyol compound and a curing agent containing an isocyanate compound. Preferred are two-component curable polyurethane adhesives containing a polyester such as a polyester polyol, a polyether polyol, and an acrylic polyol as a main component and an aromatic or aliphatic polyisocyanate as a curing agent. Further, as the polyol compound, it is preferable to use a polyester polyol having a hydroxyl group in the side chain in addition to the hydroxyl group at the terminal of the repeating unit. Since the first adhesive layer 21 is formed of a polyurethane adhesive, excellent electrolytic solution resistance is imparted to the exterior material for a power storage device, and the first base material layer 11 is peeled off even if the electrolytic solution adheres to the side surface. Is suppressed.

Further, the first adhesive layer 21 may contain a colorant, a thermoplastic elastomer, a tackifier, a filler and the like, as long as the adhesiveness is not impaired, the addition of other components is permitted. Since the first adhesive layer 21 contains a colorant, the exterior material for a power storage device can be colored. As the colorant, known ones such as pigments and dyes can be used. Further, as the colorant, only one kind may be used, or two or more kinds may be mixed and used.

The type of pigment is not particularly limited as long as it does not impair the adhesiveness of the first adhesive layer 21. Examples of organic pigments include azo-based, phthalocyanine-based, quinacridone-based, anthracinone-based, dioxazine-based, indigothioindigo-based, perinone-perylene-based, isoindrenine-based, and benzimidazolone-based pigments, which are inorganic. Examples of the pigment include carbon black-based, titanium oxide-based, cadmium-based, lead-based, chromium oxide-based, and iron-based pigments, and other examples include fine powder of mica (mica) and fish scale foil.

Among the colorants, carbon black is preferable, for example, in order to make the appearance of the exterior material for a power storage device black.

The average particle size of the pigment is not particularly limited, and examples thereof include about 0.05 to 5 μm, preferably about 0.08 to 2 μm. The average particle size of the pigment is the median size measured by the laser diffraction / scattering type particle size distribution measuring device.

The content of the pigment in the first adhesive layer 21 is not particularly limited as long as the exterior material for the power storage device is colored, and examples thereof include about 5 to 60% by mass, preferably 10 to 40% by mass.

The thickness of the first adhesive layer 21 is preferably 5 μm or less, preferably about 1 to 5 μm, from the viewpoint of improving the moldability while reducing the thickness of the exterior material for the power storage device.

[Second adhesive layer 22]
In the exterior material for a power storage device of the present disclosure, the second adhesive layer 22 is a layer provided for adhering the second base material layer 12 and the barrier layer 3.

As described above, in the exterior material for the power storage device of the present disclosure, it is preferable that the hardness of the first adhesive layer 21 and the hardness of the second adhesive layer 22 are 20 MPa or more, respectively. As a result, particularly excellent moldability is exhibited in the exterior material for a power storage device in which the base material layer is formed of a plurality of layers (that is, the first base material layer 11 and the second base material layer 12). More specifically, when the hardness of the first adhesive layer 21 and the second adhesive layer 22 measured by the nanoindentation method is 20 MPa or more, particularly excellent moldability is exhibited.

From the viewpoint of further improving the moldability of the exterior material for the power storage device, the hardness of the second adhesive layer 22 is more preferably 30 MPa or more, further preferably 51 MPa or more, preferably 400 MPa or less, and more preferably 350 MPa. The following can be mentioned. Preferred ranges of the hardness of the second adhesive layer 22 include about 20 to 400 MPa, about 20 to 350 MPa, about 30 to 400 MPa, about 30 to 350 MPa, about 51 to 400 MPa, and about 51 to 350 MPa.

In the present disclosure, the hardness measured by the nanoindentation method of the second adhesive layer 22 is a value measured by the above-mentioned method.

As with the first adhesive layer 21, the hardness of the second adhesive layer 22 is not only the type of resin contained in the adhesive, but also the molecular weight of the resin, the number of cross-linking points, the ratio of the main agent and the curing agent, and the hardness. The above values can be adjusted by adjusting the dilution ratio of the main agent and the curing agent, the drying temperature, the aging temperature, the aging time, and the like.

The adhesive used for forming the second adhesive layer 22 is not particularly limited as long as it can provide the second adhesive layer 22 with the above-mentioned hardness, and the above-mentioned first adhesive is not particularly limited. The same as layer 21 is exemplified. That is, as specific examples of the adhesive component and the adhesive that can be used for forming the second adhesive layer 22, the same ones as those of the above-mentioned first adhesive layer 21 are exemplified.

Further, the second adhesive layer 22 may contain a colorant, a thermoplastic elastomer, a tackifier, a filler and the like. Since the second adhesive layer 22 contains a colorant, the exterior material for the power storage device can be colored. As the colorant, known ones such as pigments and dyes can be used. Further, as the colorant, only one kind may be used, or two or more kinds may be mixed and used.

Among the colorants, carbon black is preferable, for example, in order to make the appearance of the exterior material for a power storage device black.

The average particle size of the pigment is not particularly limited, and examples thereof include about 0.05 to 5 μm, preferably about 0.08 to 2 μm. The average particle size of the pigment is the median size measured by the laser diffraction / scattering type particle size distribution measuring device.

The content of the pigment in the second adhesive layer 22 is not particularly limited as long as the exterior material for the power storage device is colored, and examples thereof include about 5 to 60% by mass, preferably 10 to 40% by mass.

The thickness of the second adhesive layer 22 is preferably 5 μm or less, preferably about 1 to 5 μm, from the viewpoint of improving the moldability while reducing the thickness of the exterior material for the power storage device.

[Colored layer]
The colored layer is, for example, a layer provided between the second base material layer 12 and the barrier layer 3 as needed (not shown). The colored layer may be provided between the second base material layer 12 and the second adhesive layer 22, and between the second adhesive layer 22 and the barrier layer 3. Further, a colored layer may be provided on the outside of the second base material layer 12. By providing the colored layer, the exterior material for the power storage device can be colored.

The colored layer can be formed, for example, by applying an ink containing a colorant to the surface of the second base material layer 12, the surface of the barrier layer 3, and the like. As the colorant, known ones such as pigments and dyes can be used. Further, as the colorant, only one kind may be used, or two or more kinds may be mixed and used.

Specific examples of the colorant contained in the colored layer include the same as those exemplified in the column of [First Adhesive Layer 21].

[Barrier layer 3]
In the exterior material for a power storage device, the barrier layer 3 is at least a layer that suppresses the infiltration of water.

Examples of the barrier layer 3 include a metal foil having a barrier property, a thin-film deposition film, a resin layer, and the like. Examples of the vapor deposition film include a metal vapor deposition film, an inorganic oxide vapor deposition film, a carbon-containing inorganic oxide vapor deposition film, and the like, and examples of the resin layer include polymers and tetras mainly composed of polyvinylidene chloride and chlorotrifluoroethylene (CTFE). Examples thereof include polymers having a main component of fluoroethylene (TFE), polymers having a fluoroalkyl group, fluororesins such as polymers having a fluoroalkyl unit as a main component, and ethylene vinyl alcohol copolymers. Further, examples of the barrier layer 3 include a resin film provided with at least one of these vapor-deposited films and a resin layer. A plurality of barrier layers 3 may be provided. The barrier layer 3 preferably includes a layer made of a metal material. Specific examples of the metal material constituting the barrier layer 3 include aluminum alloys, stainless steels, titanium steels, steel plates, and the like, and when used as metal foils, include at least one of aluminum alloy foils and stainless steel foils. Is preferable.

From the viewpoint of improving the moldability of the exterior material for the power storage device, the aluminum alloy foil is more preferably a soft aluminum alloy foil made of, for example, an annealed aluminum alloy, and the viewpoint of further improving the moldability. Therefore, it is preferable that the aluminum alloy foil contains iron. In the aluminum alloy foil containing iron (100% by mass), the iron content is preferably 0.1 to 9.0% by mass, more preferably 0.5 to 2.0% by mass. When the iron content is 0.1% by mass or more, an exterior material for a power storage device having better moldability can be obtained. When the iron content is 9.0% by mass or less, a more flexible exterior material for a power storage device can be obtained. As the soft aluminum alloy foil, for example, an aluminum alloy having a composition specified by JIS H4160: 1994 A8021H-O, JIS H4160: 1994 A8079H-O, JIS H4000: 2014 A8021P-O, or JIS H4000: 2014 A8079P-O. Foil is mentioned. Further, if necessary, silicon, magnesium, copper, manganese and the like may be added. Further, softening can be performed by annealing or the like.

Examples of the stainless steel foil include austenite-based, ferrite-based, austenite-ferritic-based, martensitic-based, and precipitation-hardened stainless steel foils. Further, from the viewpoint of providing an exterior material for a power storage device having excellent formability, the stainless steel foil is preferably made of austenitic stainless steel.

Specific examples of the austenitic stainless steel constituting the stainless steel foil include SUS304, SUS301, and SUS316L, and among these, SUS304 is particularly preferable.

In the case of a metal foil, the thickness of the barrier layer 3 may be at least a function as a barrier layer for suppressing the infiltration of water, and is, for example, about 9 to 200 μm. The thickness of the barrier layer 3 is, for example, preferably about 85 μm or less, more preferably about 50 μm or less, still more preferably about 40 μm or less, particularly preferably about 35 μm or less for the upper limit, and preferably about about 35 μm or less for the lower limit. 10 μm or more, more preferably about 20 μm or more, more preferably about 25 μm or more, and preferable ranges of the thickness are about 10 to 85 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 35 μm, and 20 to 20. About 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, about 25 to 35 μm, and among these, about 25 to 50 μm, Further, about 25 to 40 μm is particularly preferable. When the barrier layer 3 is made of an aluminum alloy foil, the above range is particularly preferable. Further, in particular, when the barrier layer 3 is made of 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, still more preferably about 40 μm or less. Further preferably, it is about 30 μm or less, 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, and the preferred thickness range is about 10 to 60 μm, 10 Examples thereof include about 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.

[Corrosion resistant film 3a, 3b]
The exterior material for a power storage device of the present disclosure is provided with a corrosion-resistant film on the surface of at least one side of the barrier layer 3. In the exterior material for a power storage device of the present disclosure, the corrosion resistant film 3a may be provided only on the surface of the barrier layer 3 on the heat-sealing resin layer 4 side, or the second base material layer of the barrier layer 3 may be provided. Corrosion-resistant films 3b may be provided only on the surface on the 12 side, or corrosion-resistant films 3a and 3b may be provided on both sides of the barrier layer 3, respectively.

In the exterior material for power storage devices of the present disclosure, when the corrosion-resistant film is analyzed by using the time-of-flight type secondary ion mass spectrometry, the peak intensity P _{CrPO 4} ^{derived from CrPO 4 −} becomes PO ₃ ⁻ . It is characterized in that the ratio P _{PO3 / CrPO4} of the derived peak intensity P _PO3 is in the range of 6 to 120. Since the peak intensity ratio is within such a specific range, even if the electrolytic solution adheres to the exterior material for the power storage device, the barrier layer 3 has a layer adjacent to the side where the corrosion resistant film is provided. Has excellent adhesion.

When the corrosion-resistant films 3a and 3b are provided on both sides of the barrier layer 3, the peak intensity ratio P _{PO3 / CrPO4} in the corrosion-resistant film on either side may be within the above range. However, it is preferable that the _{peak intensity ratio P PO3 / CrPO4} is within the above range for both the corrosion resistant films 3a and 3b. In particular, the corrosion-resistant film located on the heat-sealing resin layer side of the barrier layer and the layer adjacent to the corrosion-resistant film (for example, an adhesive layer provided as needed, a heat-sealing resin layer, etc.) Since the adhesion tends to decrease due to the permeation of the electrolytic solution, the exterior material for the power storage device of the present disclosure is provided with a corrosion-resistant film 3a on the surface of the barrier layer 3 at least on the heat-sealing resin layer 4 side. It is preferable that the peak intensity ratio P _{PO3 / CrPO4} for the corrosion-resistant film 3a is within the above range. The same applies to each of the peak intensity ratios shown below.

In the present disclosure, CrPO ₄ ^- PO ₃ to the peak intensity P _CrPO4 derived from ^- the ratio P _{PO3 / CrPO4} the peak intensity P _PO3 derived is may be in the range of 6 to 120, provided with a corrosion-resistant coating From the viewpoint of further enhancing the adhesion of the barrier layer _{, the lower limit of the ratio P PO3 / CrPO4} is about 10 or more, and the upper limit is preferably about 115 or less, more preferably about 110 or less, still more preferably about. 50 or less can be mentioned. The preferred range of the ratio P _{PO3 / CrPO4} is about 6 to 115, about 6 to 110, about 6 to 50, about 10 to 120, about 10 to 115, about 10 to 110, and about 10 to 50. Be done.

The method for analyzing the corrosion-resistant films 3a and 3b using the time-of-flight type secondary ion mass spectrometry is specifically carried out under the following measurement conditions using a time-of-flight type secondary ion mass spectrometer. be able to.

(Measurement condition)
Primary ion: Double charge ion of bismuth cluster (Bi ₃ ⁺⁺ )
Primary ion acceleration voltage: 30 kV
Mass range (m / z): 0 to 1500
Measurement range: 100 μm × 100 μm
Number of scans: 16 scan / cycle
Number of pixels (1 side): 256 pixels
Etching Ions: Ar Gas Cluster Ion Beam (Ar-GCIB)
Etching ion acceleration voltage: 5.0 kV

Further, it can be confirmed by X-ray photoelectron spectroscopy that the corrosion-resistant film contains chromium. Specifically, first, in the exterior material for a power storage device, the layer laminated on the barrier layer (adhesive layer, heat-sealing resin layer, adhesive layer, etc.) is physically peeled off. Next, the barrier layer is placed in an electric furnace, and the organic components present on the surface of the barrier layer are removed at about 300 ° C. for about 30 minutes. Then, X-ray photoelectron spectroscopy on the surface of the barrier layer is used to confirm that chromium is contained.

The corrosion-resistant films 3a and 3b can be formed by chemical conversion treatment of the surface of the barrier layer 3 with a treatment liquid containing a chromium compound such as chromium oxide.

As a chemical conversion treatment using a treatment liquid containing a chromium compound, for example, a solution in which a chromium compound such as chromium oxide is dispersed in phosphoric acid and / or a salt thereof is applied to the surface of the barrier layer 3 and baked. By doing so, a method of forming a corrosion-resistant film on the surface of the barrier layer 3 can be mentioned.

The peak intensity ratio P _{PO3 / CrPO4} of the corrosion-resistant films 3a and 3b is adjusted by, for example, the composition of the treatment liquid forming the corrosion-resistant films 3a and 3b, the manufacturing conditions such as the temperature and time of the baking treatment after the treatment, and the like. can do.

The ratio of the chromium compound to the phosphoric acid and / or a salt thereof in the treatment liquid containing the chromium compound is not particularly limited, but _{from the viewpoint of setting the peak intensity ratio P PO3 / CrPO4} within the above range, the chromium compound. The ratio of phosphoric acid and / or a salt thereof to 100 parts by mass is preferably about 30 to 120 parts by mass, and 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.

Further, the treatment liquid containing the chromium compound may further contain an anionic polymer and a cross-linking agent for cross-linking the anionic polymer. Examples of the anionic polymer include poly (meth) acrylic acid or a salt thereof, and a copolymer containing (meth) acrylic acid or a salt thereof as a main component. Examples of the cross-linking agent include compounds having a functional group of any of an isocyanate group, a glycidyl group, a carboxyl group and an oxazoline group, and a silane coupling agent. The anionic polymer and the cross-linking agent may be one kind or two or more kinds, respectively.

Further, from the viewpoint of enhancing the adhesion of the barrier layer provided with the corrosion resistant film while exhibiting excellent corrosion resistance, it is preferable that the treatment liquid containing the chromium compound contains an amination phenol polymer. In the treatment liquid containing the chromium compound, the content of the amination phenol polymer is preferably about 100 to 400 parts by mass, more preferably about 200 to 300 parts by mass with respect to 100 parts by mass of the chromium compound. The weight average molecular weight of the amination phenol polymer is preferably about 5,000 to 20,000. The weight average molecular weight of the amination phenol polymer is a value measured by gel permeation chromatography (GPC) measured under the condition of using polystyrene as a standard sample.

The solvent of the treatment liquid containing the chromium compound is not particularly limited as long as it can disperse the components contained in the treatment liquid and evaporate by subsequent heating, but water is preferable.

The solid content concentration of the chromium compound contained in the treatment liquid forming the corrosion-resistant film is not particularly limited, but the peak intensity ratio P _{PO3 / CrPO4} is set within the above-mentioned predetermined range to obtain excellent corrosion resistance. From the viewpoint of enhancing the adhesion of the barrier layer provided with the corrosion resistant film while exhibiting, for example, about 1 to 15% by mass, preferably about 7.0 to 12.0% by mass, more preferably 8.0 to 11 About 0.0% by mass, more preferably about 9.0 to 10.0% by mass.

The thickness of the corrosion-resistant film is not particularly limited, but is preferably about 1 nm to 10 μm from the viewpoint of enhancing the adhesion of the barrier layer provided with the corrosion-resistant film while exhibiting excellent corrosion resistance. It is preferably about 1 to 100 nm, and more preferably about 1 to 50 nm. The thickness of the corrosion-resistant film can be measured by observation with a transmission electron microscope or a combination of observation with a transmission electron microscope and energy dispersion type X-ray spectroscopy or electron beam energy loss spectroscopy.

^{From the same viewpoint, the amount of the corrosion-resistant film per 1 m 2} of the surface of the barrier layer 3 is preferably about 1 to 500 mg, more preferably about 1 to 100 mg, and further preferably about 1 to 50 mg.

Examples of the method of applying the treatment liquid containing the chromium compound to the surface of the barrier layer include a bar coating method, a roll coating method, a gravure coating method, and a dipping method.

The peak intensity ratio P _{PO3 / CrPO4} is set within the above-mentioned predetermined range, and the treatment liquid is baked from the viewpoint of enhancing the adhesion of the barrier layer having the corrosion-resistant film while exhibiting excellent corrosion resistance. The heating temperature for forming the corrosion-resistant film is preferably about 170 to 250 ° C, more preferably about 180 to 230 ° C, and further preferably about 190 to 220 ° C. From the same viewpoint, the baking time is preferably about 2 to 10 seconds, more preferably about 3 to 6 seconds.

From the viewpoint of more efficient chemical conversion treatment on the surface of the barrier layer, before providing a corrosion-resistant film on the surface of the barrier layer 3, an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, and an acid It is preferable to perform the degreasing treatment by a known treatment method such as an activation method.

[Heat-fused resin layer 4]
In the exterior material for a power storage device of the present disclosure, the heat-sealing resin layer 4 corresponds to the innermost layer, and has a function of heat-sealing the heat-sealing resin layers to each other when assembling the power storage device to seal the power storage device element. It is a layer (sealant layer) that exerts.

The resin constituting the heat-fusing resin layer 4 is not particularly limited as long as it can be heat-fused, but a resin containing a polyolefin skeleton such as a polyolefin or an acid-modified polyolefin is preferable. The fact that the resin constituting the heat-sealing resin layer 4 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography-mass spectrometry, or the like. Further, when the resin constituting the heat-sealing resin layer 4 is analyzed by infrared spectroscopy, it is preferable that a peak derived from maleic anhydride is detected. For example, when measuring the infrared spectroscopy at a maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. When the heat-sealing resin layer 4 is a layer composed of maleic anhydride-modified polyolefin, a peak derived from maleic anhydride is detected when measured by infrared spectroscopy. However, if the degree of acid denaturation is low, the peak may become small and may not be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

Specific examples of the polyolefin include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymer; homopolypropylene, block copolymer of polypropylene (for example, with propylene). Polyethylene block copolymers), random copolymers of polypropylene (eg, random copolymers of propylene and ethylene); propylene-α-olefin copolymers; ethylene-butene-propylene tarpolymers and the like. Among these, polypropylene is preferable. When it is a copolymer, the polyolefin resin may be a block copolymer or a random copolymer. One of these polyolefin resins may be used alone, or two or more thereof may be used in combination.

Further, the polyolefin may be a cyclic polyolefin. The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer, and examples of the olefin which is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. Be done. Examples of the cyclic monomer which is a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene; cyclic diene such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these, cyclic alkene is preferable, and norbornene is more preferable.

The acid-modified polyolefin is a polymer modified by block-polymerizing or graft-polymerizing a polyolefin with an acid component. As the acid-modified polyolefin, the above-mentioned polyolefin, a copolymer obtained by copolymerizing the above-mentioned polyolefin with a polar molecule such as acrylic acid or methacrylic acid, or a polymer such as a crosslinked polyolefin can also be used. Examples of the acid component used for acid modification include carboxylic acids such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride, or anhydrides thereof.

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 in place of the acid component, or by block-polymerizing or graft-polymerizing the acid component with the cyclic polyolefin. be. The same applies to the cyclic polyolefin that is acid-modified. The acid component used for acid denaturation is the same as the acid component used for denaturation of the polyolefin.

Preferred acid-modified polyolefins include polyolefins modified with carboxylic acid or its anhydride, polypropylene modified with carboxylic acid or its anhydride, maleic anhydride-modified polyolefin, and maleic anhydride-modified polypropylene.

The heat-bondable resin layer 4 may be formed of one type of resin alone, or may be formed of a blended polymer in which two or more types of resins are combined. Further, the heat-sealing resin layer 4 may be formed of only one layer, but may be formed of two or more layers with the same or different resins.

Further, the heat-sealing resin layer 4 may contain a lubricant or the like, if necessary. When the heat-bondable resin layer 4 contains a lubricant, the moldability of the exterior material for a power storage device can be improved. The lubricant is not particularly limited, and a known lubricant can be used. The lubricant may be used alone or in combination of two or more.

The lubricant is not particularly limited, but an amide-based lubricant is preferable. Specific examples of the lubricant include those exemplified in the first base material layer 11. The lubricant may be used alone or in combination of two or more.

When the lubricant is present on the surface of the heat-sealing resin layer 4, the amount thereof is not particularly limited, but is preferably about ^{10 to 50 mg / m 2 from the viewpoint of improving the moldability of the exterior material for the power storage device.} , More preferably about 15 to 40 mg / m ^2.

The lubricant present on the surface of the heat-sealing resin layer 4 may be one in which the lubricant contained in the resin constituting the heat-sealing resin layer 4 is exuded, or the lubricant of the heat-sealing resin layer 4 may be exuded. The surface may be coated with a lubricant.

The thickness of the heat-sealing resin layer 4 is not particularly limited as long as the heat-sealing resin layers have a function of heat-sealing to seal the power storage device element, but is preferably about 100 μm or less, preferably. It is about 85 μm or less, more preferably about 15 to 85 μm. For example, when the thickness of the adhesive layer 5 described later is 10 μm or more, the thickness of the heat-sealing resin layer 4 is preferably about 85 μm or less, more preferably about 15 to 45 μm, for example. When the thickness of the adhesive layer 5 described later is less than 10 μm or when the adhesive layer 5 is not provided, the thickness of the heat-sealing resin layer 4 is preferably about 20 μm or more, more preferably 35 to 85 μm. The degree is mentioned.

[Adhesive layer 5]
In the exterior material for a power storage device of the present disclosure, the adhesive layer 5 is provided between the barrier layer 3 (or the corrosion-resistant film) and the heat-sealing resin layer 4 as necessary in order to firmly bond them. It is a layer to be corroded.

The adhesive layer 5 is formed of a resin capable of adhering the barrier layer 3 and the heat-sealing resin layer 4. As the resin used for forming the adhesive layer 5, for example, the same resin as the adhesive exemplified in the first adhesive layer 21 can be used. The resin used for forming the adhesive layer 5 preferably contains a polyolefin skeleton, and examples thereof include the polyolefins exemplified in the above-mentioned heat-sealing resin layer 4 and acid-modified polyolefins. The fact that the resin constituting the adhesive layer 5 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography-mass spectrometry, or the like, and the analysis method is not particularly limited. Further, when the resin constituting the adhesive layer 5 is analyzed by infrared spectroscopy, it is preferable that a peak derived from maleic anhydride is detected. For example, when measuring the infrared spectroscopy at a maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. However, if the degree of acid denaturation is low, the peak may become small and may not be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

From the viewpoint of firmly adhering the barrier layer 3 and the heat-bondable resin layer 4, the adhesive layer 5 preferably contains an acid-modified polyolefin. As the acid-modified polyolefin, a polyolefin modified with a carboxylic acid or an anhydride thereof, a polypropylene modified with a carboxylic acid or an anhydride thereof, a maleic anhydride-modified polyolefin, and a maleic anhydride-modified polypropylene are particularly preferable.

Further, from the viewpoint of reducing the thickness of the exterior material for the power storage device and making the exterior material for the power storage device excellent in shape stability after molding, the adhesive layer 5 is a resin composition containing an acid-modified polyolefin and a curing agent. It is more preferable that it is a cured product of. As the acid-modified polyolefin, the above-mentioned ones are preferably exemplified.

Further, the adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and at least one selected from the group consisting of a compound having an isocyanate group, a compound having an oxazoline group, and a compound having an epoxy group. It is particularly preferable that the resin composition is a cured product containing an acid-modified polyolefin and at least one selected from the group consisting of a compound having an isocyanate group and a compound having an epoxy group. Further, the adhesive layer 5 preferably contains at least one selected from the group consisting of polyurethane, polyester, and epoxy resin, and more preferably contains polyurethane and epoxy resin. As the polyester, for example, an amide ester resin is preferable. The amide ester resin is generally produced by the reaction of a carboxyl group and an oxazoline group. The adhesive layer 5 is more preferably a cured product of a resin composition containing at least one of these resins and the acid-modified polyolefin. When an unreacted substance of a curing agent such as a compound having an isocyanate group, a compound having an oxazoline group, or an epoxy resin remains in the adhesive layer 5, the presence of the unreacted substance is, for example, infrared spectroscopy. It can be confirmed by a method selected from Raman spectroscopy, time-of-flight secondary ion mass spectrometry (TOF-SIMS), and the like.

Further, from the viewpoint of further enhancing the adhesion between the barrier layer 3 and the adhesive layer 5, the adhesive layer 5 is selected from at least a group consisting of an oxygen atom, a heterocycle, a C = N bond, and a C—O—C bond. It is preferably a cured product of a resin composition containing one type of curing agent. Examples of the curing agent having a heterocycle include a curing agent having an oxazoline group and a curing agent having an epoxy group. Examples of the curing agent having a C = N bond include a curing agent having an oxazoline group and a curing agent having an isocyanate group. Examples of the curing agent having a C—O—C bond include a curing agent having an oxazoline group, a curing agent having an epoxy group, and polyurethane. The fact that the adhesive layer 5 is a cured product of a resin composition containing these curing agents is, for example, gas chromatograph mass spectrometry (GCMS), infrared spectroscopy (IR), time-of-flight secondary ion mass spectrometry (TOF). -SIMS), X-ray photoelectron spectroscopy (XPS) and other methods can be used for confirmation.

The compound having an isocyanate group is not particularly limited, but a polyfunctional isocyanate compound is preferable from the viewpoint of effectively enhancing the adhesion between the barrier layer 3 and the adhesive layer 5. The polyfunctional isocyanate compound is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of the polyfunctional isocyanate-based curing agent include pentandiisocyanate (PDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), and diphenylmethane diisocyanate (MDI), which are polymerized or nurate. Examples thereof include chemical compounds, mixtures thereof, and copolymers with other polymers. Further, an adduct body, a burette body, an isocyanate body and the like can be mentioned.

The content of the compound having an isocyanate group in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, and 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. It is more preferable to be in the range. This makes it possible to effectively improve the adhesion between the barrier layer 3 and the adhesive layer 5.

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.

The proportion of the compound having an oxazoline group in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, preferably in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. It is more preferable to be in. This makes it possible to effectively improve the adhesion between the barrier layer 3 and the adhesive layer 5.

Examples of the compound having an epoxy group include an epoxy resin. The epoxy resin is not particularly limited as long as it is a resin capable of forming a crosslinked structure by an epoxy group existing in the molecule, and a known epoxy resin can be used. The weight average molecular weight of the epoxy resin is preferably about 50 to 2000, more preferably about 100 to 1000, and even more preferably about 200 to 800. In the first disclosure, the weight average molecular weight of the epoxy resin is a value measured by gel permeation chromatography (GPC) measured under the condition of using polystyrene as a standard sample.

Specific examples of the epoxy resin include glycidyl ether derivatives of trimethylolpropane, bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolak glycidyl ether, glycerin polyglycidyl ether, polyglycerin polyglycidyl ether and the like. One type of epoxy resin may be used alone, or two or more types may be used in combination.

The proportion of the epoxy resin in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, preferably in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. Is more preferable. This makes it possible to effectively improve the adhesion between the barrier layer 3 and the adhesive layer 5.

The polyurethane is not particularly limited, and known polyurethane can be used. The adhesive layer 5 may be, for example, a cured product of a two-component curable polyurethane.

The proportion of polyurethane in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, preferably in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. More preferred. This makes it possible to effectively enhance the adhesion between the barrier layer 3 and the adhesive layer 5 in an atmosphere in which a component that induces corrosion of the barrier layer such as an electrolytic solution is present.

When the adhesive layer 5 is a cured product of a resin composition containing at least one selected from the group consisting of a compound having an isocyanate group, a compound having an oxazoline group, and an epoxy resin, and the acid-modified polyolefin. , The acid-modified polyolefin functions as a main agent, and the compound having an isocyanate group, the compound having an oxazoline group, and the compound having an epoxy group each function as a curing agent.

The upper limit of the thickness of the adhesive layer 5 is preferably about 50 μm or less, about 40 μm or less, about 30 μm or less, about 20 μm or less, about 5 μm or less, and the lower limit is preferably about 0.1 μm or more. , About 0.5 μm or more, and the thickness range is preferably about 0.1 to 50 μm, about 0.1 to 40 μm, about 0.1 to 30 μm, about 0.1 to 20 μm, and 0. .1 to 5 μm, 0.5 to 50 μm, 0.5 to 40 μm, 0.5 to 30 μm, 0.5 to 20 μm, 0.5 to 5 μm, and the like. More specifically, in the case of the adhesive exemplified in the adhesive layer 2 or the cured product of the acid-modified polyolefin and the curing agent, the thickness is preferably about 1 to 10 μm, more preferably about 1 to 5 μm. Further, when the resin exemplified in the heat-sealing resin layer 4 is used, it is preferably about 2 to 50 μm, more preferably about 10 to 40 μm. When the adhesive layer 5 is a cured product of the adhesive exemplified in the adhesive layer 2 or a resin composition containing an acid-modified polyolefin and a curing agent, for example, the resin composition is applied and cured by heating or the like. Thereby, the adhesive layer 5 can be formed. Further, when the resin exemplified in the heat-sealing resin layer 4 is used, it can be formed by, for example, extrusion molding of the heat-sealing resin layer 4 and the adhesive layer 5.

[Surface coating layer 6]
The exterior material for a power storage device of the present disclosure is, if necessary, on the first base material layer 11 (first) for the purpose of improving at least one of designability, electrolytic solution resistance, scratch resistance, moldability, and the like. The surface coating layer 6 may be provided on the side of the base material layer 11 opposite to the barrier layer 3. The surface coating layer 6 is a layer located on the outermost layer side of the exterior material for the power storage device when the power storage device is assembled using the exterior material for the power storage device.

The surface coating layer 6 can be formed of, for example, a resin such as polyvinylidene chloride, polyester, polyurethane, an acrylic resin, or an epoxy resin.

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

Examples of the two-component curable polyurethane include a polyurethane containing a main agent containing a polyol compound and a curing agent containing an isocyanate compound. Preferred are two-component curable polyurethanes containing a polyester such as a polyester polyol, a polyether polyol, and an acrylic polyol as a main component and an aromatic or aliphatic polyisocyanate as a curing agent. Further, as the polyol compound, it is preferable to use a polyester polyol having a hydroxyl group in the side chain in addition to the hydroxyl group at the terminal of the repeating unit. Since the surface coating layer 6 is made of polyurethane, excellent electrolytic solution resistance is imparted to the exterior material for the power storage device.

The surface coating layer 6 has the above-mentioned lubricant or antistatic agent on at least one of the surface and the inside of the surface coating layer 6, depending on the functionality and the like to be provided on the surface coating layer 6 and the surface thereof. It may contain additives such as a blocking agent, a matting agent, a flame retardant, an antioxidant, a tackifier, and an antistatic agent. Examples of the additive include fine particles having an average particle size of about 0.5 nm to 5 μm. The average particle size of the additive shall be the median size measured by the laser diffraction / scattering type particle size distribution measuring device.

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

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, neodium oxide, and 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, refractory nylon, acrylate resin, Examples thereof include cross-linked acrylic, cross-linked styrene, cross-linked polyethylene, benzoguanamine, gold, aluminum, copper and nickel. The additive may be used alone or in combination of two or more. Among these additives, silica, barium sulfate, and titanium oxide are preferable from the viewpoint of dispersion stability and cost. Further, the additive may be subjected to various surface treatments such as an insulation treatment and a high dispersibility treatment on the surface.

The method for forming the surface coating layer 6 is not particularly limited, and examples thereof include a method of applying a resin for forming the surface coating layer 6. When the additive is blended in the surface coating layer 6, a resin mixed with the additive may be applied.

The thickness of the surface coating layer 6 is not particularly limited as long as it exhibits the above-mentioned functions as the surface coating layer 6, and examples thereof include about 0.5 to 10 μm, preferably about 1 to 5 μm.

3. 3. Method for Manufacturing Exterior Material for Power Storage Device The method for manufacturing the exterior material for power storage device is not particularly limited as long as a laminated body in which each layer of the exterior material for power storage device of the present disclosure is laminated can be obtained, and at least the first method is used. A step of laminating the base material layer 11, the first adhesive layer 21, the second base material layer 12, the second adhesive layer 22, the barrier layer 3, and the heat-sealing resin layer 4 in this order is provided. The method can be mentioned. That is, the method for producing an exterior material for a power storage device according to the present disclosure is at least a first base material layer, a first adhesive layer, a second base material layer, a second adhesive layer, a barrier layer, and a heat-sealing resin. A step of laminating the layers in this order to obtain a laminated body is provided, and when the barrier layers are laminated, a corrosion-resistant film is provided on the surface of at least one side of the barrier layer. the corrosion-resistant coating, flight when analyzed with time-of secondary ion mass spectrometry, CrPO ₄ ^- PO ₃ to the peak intensity P _CrPO4 derived from ^- the ratio of the peak intensity P _PO3 derived from P _{PO3 / CrPO4} Is in the range of 6 to 120.

An example of the method for manufacturing the exterior material for the power storage device of the present disclosure is as follows. First, a laminate in which the first substrate layer 11, the first adhesive layer 21, the second substrate layer 12, the second adhesive layer 22, and the barrier layer 3 are laminated in this order (hereinafter referred to as "laminate A"). (Sometimes) to form. In forming the laminated body A, it is preferable to prepare a laminated body in which the first base material layer 11, the first adhesive layer 21, and the second base material layer 12 are laminated in this order. In the laminate, the adhesive used for forming the first adhesive layer 21 is applied to the first base material layer 11 or the second base material layer 12 by a coating method such as a gravure coating method or a roll coating method. After drying, the first base material layer 11 and the second base material layer 12 are laminated via the adhesive, and the first adhesive layer 21 is cured by a dry laminating method. Next, the adhesive used for forming the second adhesive layer 22 is applied to the second base material layer 12 side of the obtained laminate or the barrier layer 3 (which has a corrosion resistant film). After coating and drying by a coating method such as a coating method or a roll coating method, the second base material layer 12 side of the laminated body and the barrier layer 3 are laminated via the adhesive to form the second adhesive layer 22. The laminated body A is obtained by the dry laminating method of curing.
Next, the adhesive layer 5 and the heat-sealing resin layer 4 are laminated on the barrier layer 3 of the laminated body A in this order. For example, (1) a method of laminating the adhesive layer 5 and the heat-sealing resin layer 4 on the barrier layer 3 of the laminated body A by co-extruding (co-extruded laminating method), (2) separately, the adhesive layer 5 A method of forming a laminated body in which the heat-sealing resin layer 4 is laminated and laminating this on the barrier layer 3 of the laminated body A by a thermal laminating method. (3) Adhesion on the barrier layer 3 of the laminated body A. An adhesive for forming the layer 5 is coated by an extrusion method or a solution, dried at a high temperature, and laminated by a baking method or the like, and a heat-sealing resin layer 4 is previously formed into a sheet on the adhesive layer 5. A method of laminating by a thermal laminating method, (4) Adhesion while pouring a melted adhesive layer 5 between the barrier layer 3 of the laminated body A and the heat-sealing resin layer 4 previously formed into a sheet. Examples thereof include a method of laminating the laminate A and the heat-sealing resin layer 4 via the layer 5 (sandwich laminating method).

When the surface coating layer 6 is provided, the surface coating layer 6 is laminated on the surface of the first base material layer 11 opposite to the barrier layer 3. The surface coating layer 6 can be formed, for example, by applying the above resin forming the surface coating layer 6 to the surface of the first base material layer 11. The order of the step of laminating the barrier layer 3 on the surface of the first base material layer 11 and the step of laminating the surface coating layer 6 on the surface of the first base material layer 11 is not particularly limited. For example, after forming the surface coating layer 6 on the surface of the first base material layer 11, the barrier layer 3 may be formed on the surface of the first base material layer 11 opposite to the surface coating layer 6.

Curing of the first adhesive layer 21 is carried out, for example, by performing aging at the stage where a laminate of the first base material layer 11, the first adhesive layer 21 and the second base material layer 12 is obtained. Further, it can be carried out by aging the laminated body A in which the barrier layer 3 is laminated. Further, the curing of the second adhesive layer 22 can be carried out by aging the laminated body of the second base material layer 12, the second adhesive layer 22 and the barrier layer, or the laminated body A can be aged. It can also be carried out by performing aging after laminating the adhesive layer 5 and the heat-sealing resin layer 4 provided as needed. As described above, the curing conditions of the first adhesive layer 21 and the second adhesive layer 22 are adjusted so as to have the above-mentioned predetermined hardness according to the type of the adhesive used for forming these layers and the like. The aging conditions are not particularly limited, and examples thereof include a temperature of about 60 to 120 ° C. and a time of about 12 to 120 hours.

As described above, on the surface coating layer 6 / first base material layer 11 / first adhesive layer 21 / second base material layer 12 / second adhesive layer 22 / at least one surface provided as needed. A laminate consisting of a barrier layer 3 having a corrosion-resistant film, an adhesive layer 5 provided as needed, and a heat-sealing resin layer 4 is formed, but the first adhesive layer 21 or the second adhesive layer 22 is formed. In order to strengthen the adhesiveness of the product, it may be further subjected to a heat treatment such as a hot roll contact type, a hot air type, a near infrared type or a far infrared type. Examples of the conditions for such heat treatment include 1 to 5 minutes at 150 to 250 ° C.

In the exterior material for a power storage device, each layer constituting the laminated body may be subjected to surface activation treatment such as corona treatment, blast treatment, oxidation treatment, ozone treatment, etc., if necessary, to improve processing suitability. .. For example, by applying a corona treatment to the surface of the first base material layer 11 opposite to the barrier layer 3, it is possible to improve the printability of the ink on the surface of the first base material layer 11.

4. Applications of Exterior Materials for Energy Storage Devices The exterior materials for energy storage devices of the present disclosure are used in packages for sealing and accommodating energy storage device elements such as positive electrodes, negative electrodes, and electrolytes. That is, a power storage device element having at least a positive electrode, a negative electrode, and an electrolyte can be housed in a package formed of the exterior material for a power storage device of the present disclosure to form a power storage device.

Specifically, the power storage device element provided with at least a positive electrode, a negative electrode, and an electrolyte is the exterior material for the power storage device of the present disclosure, in a state where the metal terminals connected to each of the positive electrode and the negative electrode are projected outward. , The peripheral edge of the power storage device element is covered so that a flange portion (a region where the heat-sealing resin layers come into contact with each other) can be formed, and the heat-sealing resin layers of the flange portion are heat-sealed and sealed. Provides a power storage device using an exterior material for a power storage device. When the power storage device element is housed in the package formed of the power storage device exterior material of the present disclosure, the heat-sealing resin portion of the power storage device exterior material of the present disclosure is inside (the surface in contact with the power storage device element). ) To form a package.

The exterior material for a power storage device of the present disclosure can be suitably used for a power storage device such as a power storage device (including a capacitor, a capacitor, etc.). Further, the exterior material for a power storage device of the present disclosure may be used for either a primary power storage device or a secondary power storage device, but is preferably a secondary power storage device. The type of the secondary storage device to which the exterior material for the power storage device of the present disclosure is applied is not particularly limited, and for example, a lithium ion power storage device, a lithium ion polymer power storage device, an all-solid power storage device, a lead storage battery, and a nickel / hydrogen battery. Examples thereof include storage batteries, nickel-cadmium storage batteries, nickel-iron storage batteries, nickel-zinc storage batteries, silver oxide / zinc storage batteries, metal-air storage devices, polyvalent cation storage devices, capacitors, capacitors and the like. Among these secondary power storage devices, lithium ion power storage devices and lithium ion polymer power storage devices can be mentioned as suitable application targets of the exterior materials for power storage devices of the present disclosure.

Hereinafter, the present disclosure will be described in detail with reference to Examples and Comparative Examples. However, the present disclosure is not limited to the examples.

<Manufacturing of exterior materials for power storage devices>
Example 1
A two-component polyurethane adhesive (polyol compound and aromatic isocyanate compound, cured) that forms a first adhesive layer on a first substrate layer made of a stretched nylon film (thickness 15 μm) by the dry laminating method. The latter thickness is 3 μm), and a second base material layer made of a stretched nylon film (thickness 25 μm) is laminated on the first base material layer / first adhesive layer / second base material layer. Was obtained in order to obtain a laminated body. Next, the second base material layer side of the obtained laminate was subjected to chemical conversion treatment on both sides by a method described later, and an aluminum alloy foil (JIS H4160: 1994 A8021H) provided with a corrosion resistant film (thickness 10 nm) was provided. A barrier layer composed of −O (thickness 40 μm) was laminated by a dry laminating method. Specifically, a two-component polyurethane adhesive (polypoly compound and aromatic isocyanate compound) forming a second adhesive layer is applied to one surface of an aluminum alloy foil having a corrosion-resistant film to form a barrier. A second adhesive layer (thickness after curing 3 μm) was formed on the layer. Next, by laminating the second adhesive layer on the barrier layer and the second base material layer side of the laminated body, the first base material layer / first adhesive layer / second base material layer / second adhesion A laminated body A of the agent layer / barrier layer was prepared.

The laminate A was subjected to an aging treatment under the aging treatment conditions shown in Table 1, and the hardness of the first adhesive layer and the second adhesive layer was adjusted. Specifically, under the aging treatment conditions of Example 1, the laminated body A in which the first base material layer / the first adhesive layer / the second base material layer / the second adhesive layer / the barrier layer are laminated in this order is The first adhesive layer and the second adhesive layer were simultaneously cured under the aging treatment conditions (80 ° C. for 24 hours) shown in Table 1.

The corrosion-resistant film was formed on the surface of the barrier layer as follows. A treatment liquid containing 43 parts by mass of the amination phenol polymer, 16 parts by mass of chromium fluoride, and 13 parts by mass of phosphoric acid was prepared with respect to 100 parts by mass of water, and the treatment liquid was applied to both sides of the barrier layer (after drying). The thickness of the barrier layer was about 10 nm), and the surface temperature of the barrier layer was about 190 to 230 ° C., and the mixture was heated and dried for about 3 to 6 seconds.

Next, on the barrier layer of the obtained laminate A, anhydrous maleic acid-modified polypropylene (thickness 20 μm) as an adhesive layer and random polypropylene (thickness 15 μm) as a heat-sealing resin layer were coextruded. By doing so, the adhesive layer / heat-sealing resin layer is laminated on the barrier layer, and the first base material layer (15 μm) / first adhesive layer (3 μm) / second base material layer (25 μm) / first An exterior material for a power storage device was obtained, which was composed of a laminate B in which two adhesive layers (3 μm) / barrier layer (40 μm) / adhesive layer (20 μm) / heat-sealing resin layer (15 μm) were laminated in this order.

Example 2
Same as Example 1 except that an aluminum alloy foil (JIS H4160: 1994 A8021HO, thickness 35 μm) having the same corrosion resistant film (thickness 10 nm) as in Example 1 was used as the barrier layer. First base material layer (15 μm) / first adhesive layer (3 μm) / second base material layer (25 μm) / second adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (20 μm) / An exterior material for a power storage device made of a laminated body B in which a heat-sealing resin layer (15 μm) was laminated in order was obtained.

Example 3
A stretched nylon film (thickness 15 μm) was used as the second base material layer, and maleic anhydride-modified polypropylene (thickness 23 μm) as the adhesive layer and random polypropylene (thickness) as the heat-sealing resin layer. The first base material layer (15 μm) / first in the same manner as in Example 1 except that the adhesive layer / heat-sealing resin layer was laminated on the barrier layer by co-extruding (22 μm). The adhesive layer (3 μm) / second base material layer (15 μm) / second adhesive layer (3 μm) / barrier layer (40 μm) / adhesive layer (23 μm) / heat-sealing resin layer (22 μm) are laminated in this order. An exterior material for a power storage device made of the laminated body B was obtained.

Example 4
A stretched nylon film (thickness 15 μm) was used as the second base material layer, anhydrous maleic acid-modified polypropylene (thickness 40 μm) as the adhesive layer, and random polypropylene (thickness 40 μm) as the heat-sealing resin layer. ) Was co-extruded to laminate an adhesive layer / heat-sealing resin layer on the barrier layer, and a first base material layer / first adhesive layer / second base material layer / second adhesion. The first adhesive layer and the second adhesive layer were simultaneously cured under the aging treatment conditions (120 ° C. for 24 hours) shown in Table 1 for the laminated body A in which the agent layer / barrier layer were laminated in order. Except for the above, in the same manner as in Example 1, the first base material layer (15 μm) / first adhesive layer (3 μm) / second base material layer (15 μm) / second adhesive layer (3 μm) / barrier layer ( An exterior material for a power storage device was obtained, which was composed of a laminate B in which an adhesive layer (40 μm) / a heat-sealing resin layer (40 μm) was laminated in this order.

Example 5
A first made of a stretched nylon film (thickness 15 μm) on a barrier layer made of an aluminum alloy foil (JIS H4160: 1994 A8021HO, thickness 40 μm) having the same corrosion resistant film as in Example 1. The two base material layers were laminated by the dry laminating method. Specifically, a two-component polyurethane adhesive (polypoly compound and aromatic isocyanate compound) forming a second adhesive layer is applied to one surface of an aluminum alloy foil having a corrosion-resistant film to form a barrier. A second adhesive layer (thickness after curing 3 μm) is formed on the layer, and a second base material layer made of a stretched nylon film is laminated on the second base material layer / second base material layer / barrier. A laminated body of layers was obtained. Next, by the dry laminating method, the two-component polyurethane adhesive (polypoly compound and aromatic isocyanate-based compound, the thickness after curing, which forms the first adhesive layer on the second base material layer side of the laminate, is the thickness after curing. 3 μm) is applied, and a first base material layer made of a biaxially stretched polyethylene terephthalate film (thickness 15 μm) is laminated on the first base material layer / first base material layer / first adhesive layer / second base material layer. / The laminated body A of the second adhesive layer / barrier layer was prepared.

The aging treatment was performed under the aging treatment conditions shown in Table 1, and the hardness of the first adhesive layer and the second adhesive layer was adjusted. Specifically, in the aging treatment conditions of Example 5, the aging treatment conditions (24 at 80 ° C.) shown in Table 1 at the stage of producing the laminate of the second base material layer / second adhesive layer / barrier layer. The second adhesive layer was cured in time), and then the first base material layer / first adhesive layer / second base material layer / second adhesive layer / barrier layer were laminated in this order. The first adhesive layer was cured under the aging treatment conditions (60 ° C. for 24 hours) shown in Table 1.

The corrosion-resistant film was formed on the surface of the barrier layer in the same manner as in Example 1.

Next, on the barrier layer of the obtained laminate A, anhydrous maleic acid-modified polypropylene (thickness 40 μm) as an adhesive layer and random polypropylene (thickness 40 μm) as a heat-sealing resin layer are coextruded. By doing so, the adhesive layer / heat-sealing resin layer is laminated on the barrier layer, and the first base material layer (15 μm) / first adhesive layer (3 μm) / second base material layer (15 μm) / first An exterior material for a power storage device was obtained, which was composed of a laminate B in which two adhesive layers (3 μm) / barrier layer (40 μm) / adhesive layer (40 μm) / heat-sealing resin layer (40 μm) were laminated in this order.

Example 6
A stretched nylon film (thickness 15 μm) was used as the second base material layer, anhydrous maleic acid-modified polypropylene (thickness 40 μm) as the adhesive layer, and random polypropylene (thickness 40 μm) as the heat-sealing resin layer. ) Was co-extruded to laminate an adhesive layer / heat-sealing resin layer on the barrier layer, and a first base material layer / first adhesive layer / second base material layer / second adhesion. The first adhesive layer and the second adhesive layer were simultaneously cured under the aging treatment conditions (40 ° C. for 24 hours) shown in Table 1 for the laminated body A in which the agent layer / barrier layer were laminated in order. Except for the above, in the same manner as in Example 1, the first base material layer (15 μm) / first adhesive layer (3 μm) / second base material layer (15 μm) / second adhesive layer (3 μm) / barrier layer ( An exterior material for a power storage device was obtained, which was composed of a laminate B in which an adhesive layer (40 μm) / a heat-sealing resin layer (40 μm) was laminated in this order.

Example 7
Regarding the laminate A in which the first base material layer / first adhesive layer / second base material layer / second adhesive layer / barrier layer are laminated in this order, the second base material layer / second adhesive layer / barrier layer At the stage of producing the laminated body of, the second adhesive layer was cured under the aging treatment conditions (120 ° C. for 24 hours) shown in Table 1, and then the first base material layer / first adhesive layer / At the stage of producing the laminated body A in which the second base material layer / the second adhesive layer / the barrier layer are laminated in order, the first adhesive layer is subjected to the aging treatment conditions (40 ° C. for 24 hours) shown in Table 1. 1st base material layer (15 μm) / 1st adhesive layer (3 μm) / 2nd base material layer (15 μm) / 2nd adhesive layer (same as in Example 5) An exterior material for a power storage device was obtained, which was composed of a laminate B in which 3 μm) / barrier layer (40 μm) / adhesive layer (40 μm) / heat-sealing resin layer (40 μm) were laminated in this order.

Example 8
A biaxially stretched polyethylene terephthalate film (thickness 12 μm) was used as the first base material layer, a stretched nylon film (thickness 15 μm) was used as the second base material layer, and maleic anhydride as the adhesive layer. Except for laminating the adhesive layer / heat-sealing resin layer on the barrier layer by co-extruding the modified polypropylene (thickness 40 μm) and random polypropylene (thickness 40 μm) as the heat-sealing resin layer. 1st base material layer (12 μm) / 1st adhesive layer (3 μm) / 2nd base material layer (15 μm) / 2nd adhesive layer (3 μm) / barrier layer (40 μm) in the same manner as in Example 1. ) / Adhesive layer (40 μm) / Heat-sealing resin layer (40 μm) were laminated in this order to obtain an exterior material for a power storage device.

Example 9
A stretched nylon film (thickness 15 μm) was used as the second base material layer, anhydrous maleic acid-modified polypropylene (thickness 23 μm) as the adhesive layer, and random polypropylene (thickness 22 μm) as the heat-sealing resin layer. ) Was co-extruded to laminate an adhesive layer / heat-sealing resin layer on the barrier layer, and the content of phosphoric acid was determined in Example 1 in forming a corrosion-resistant film on the surface of the barrier layer. 1st base material layer (15 μm) / 1st adhesive layer (3 μm) / 2nd base material layer (15 μm) in the same manner as in Example 1 except that the value is about 1/2 times (mass ratio). An exterior material for a power storage device was obtained, which was composed of a laminate B in which a second adhesive layer (3 μm) / barrier layer (40 μm) / adhesive layer (23 μm) / heat-sealing resin layer (22 μm) were laminated in this order.

Example 10
A stretched nylon film (thickness 15 μm) was used as the second base material layer, anhydrous maleic acid-modified polypropylene (thickness 23 μm) as the adhesive layer, and random polypropylene (thickness 22 μm) as the heat-sealing resin layer. ) Was co-extruded to laminate an adhesive layer / heat-sealing resin layer on the barrier layer, and the content of phosphoric acid was determined in the formation of a corrosion-resistant film on the surface of the barrier layer. First base material layer (15 μm) / first adhesive layer (3 μm) / second base material layer (15 μm) / in the same manner as in Example 1 except that the thickness was about 1.3 times (mass ratio). An exterior material for a power storage device was obtained, which was composed of a laminate B in which a second adhesive layer (3 μm) / barrier layer (40 μm) / adhesive layer (23 μm) / heat-sealing resin layer (22 μm) were laminated in this order.

Comparative Examples 1 and 2
An aluminum alloy foil (JIS H4160: 1994 A8021H) provided with a corrosion-resistant film (thickness 10 nm) by subjecting the surface of a biaxially stretched nylon film (25 μm) as a base material layer to chemical conversion treatment on both sides by a method described later. A barrier layer composed of −O (thickness 40 μm) was laminated by a dry laminating method. Specifically, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) is applied to one surface of an aluminum alloy foil having a corrosion-resistant film to form an adhesive layer (thickness 3 μm). bottom. Next, the adhesive layer on the barrier layer provided with the corrosion-resistant film and the biaxially stretched nylon film side of the base material layer were laminated, and then an aging treatment (standing at 60 ° C. for 24 hours and then at 80 ° C.). (Standing for 24 hours) was carried out to prepare a laminated body of a biaxially stretched nylon film / adhesive layer / barrier layer having corrosion-resistant films on both sides.

Next, by co-extruding maleic anhydride-modified polypropylene and random polypropylene, maleic anhydride-modified polypropylene (23 μm) as an adhesive layer and a heat-sealing resin layer were used on the barrier layer of the laminate. Random polypropylene (23 μm) was laminated. Next, by aging the obtained laminate, a biaxially stretched nylon film (25 μm) / adhesive layer (3 μm) / barrier layer (40 μm) having a corrosion-resistant film (10 nm) on both sides / maleic anhydride. An exterior material for a power storage device was obtained in which acid-modified polypropylene (23 μm) / random polypropylene (23 μm) was laminated in this order.

In the formation of the corrosion-resistant film on the surface of the barrier layer, in Comparative Example 1, phosphoric acid was about 1/3 times (mass ratio) of Example 1, and in Comparative Example 2, phosphoric acid was 1.5 times that of Example 1. A corrosion-resistant film was formed in the same manner as in Example 1 except that the chemical conversion treatment was carried out so as to be about (mass ratio).

<Time-of-flight secondary ion mass spectrometry>
The analysis of the corrosion resistant film was performed as follows. First, the space between the barrier layer and the adhesive layer was peeled off. At this time, it was physically peeled off without using water, an organic solvent, an aqueous solution of an acid or an alkali, or the like. After peeling between the barrier layer and the adhesive layer, the adhesive layer remained on the surface of the barrier layer, so the remaining adhesive layer was removed by etching with Ar-GCIB. The surface of the barrier layer thus obtained was analyzed for a corrosion-resistant film by using a time-of-flight secondary ion mass spectrometry method. Each CrPO ₄ ^- and PO ₃ ^- and from peak intensity P _CrPO4 and P _PO3, the ratio P _{PO3 / CrPO4} the peak intensity P _PO3 to the peak intensity P _CrPO4, respectively, shown in Table 1.

The details of the measuring device and the measuring conditions of the time-of-flight secondary ion mass spectrometry are as follows.
Measuring device: Time-of-flight secondary ion mass spectrometer TOF, manufactured by ION-TOF. SIMS5
(Measurement condition)
Primary ion: Double charge ion of bismuth cluster (Bi ₃ ⁺⁺ )
Primary ion acceleration voltage: 30 kV
Mass range (m / z): 0 to 1500
Measurement range: 100 μm × 100 μm
Number of scans: 16 scan / cycle
Number of pixels (1 side): 256 pixels
Etching Ions: Ar Gas Cluster Ion Beam (Ar-GCIB)
Etching ion acceleration voltage: 5.0 kV

<Evaluation of adhesion>
By the following method, the adhesion between the barrier layer and the heat-sealing resin layer when the electrolytic solution adheres to the exterior material for the power storage device is evaluated by measuring the peel strength (N / 15 mm). rice field.

First, the exterior materials for each power storage device obtained above were cut into test pieces having sizes of 15 mm (TD: Transverse Direction, horizontal direction) and 100 mm (MD: Machine Direction, vertical direction), respectively. Put the test piece in a glass bottle and mix it with an electrolytic solution (ethylene carbonate: diethyl carbonate: dimethyl carbonate = 1: 1: 1 volume ratio) and lithium hexafluorophosphate (concentration in solution 1 × 10 ³ mol / m). ³ )) was added so that the entire test piece was immersed in the electrolytic solution. In this state, the glass bottle was covered and sealed. The sealed glass bottle was placed in an oven set at 85 ° C. and allowed to stand for 24 hours. Next, the glass bottle was taken out of the oven, and the test piece was taken out of the glass bottle and washed with water, and the water on the surface of the test piece was wiped off with a towel.

Next, the heat-fused resin layer and the barrier layer of the test piece were peeled off, and the heat-fused resin layer side and the barrier layer side of the test piece were separated from each other with a tensile tester (trade name AG-XPlus manufactured by Shimadzu Corporation). Using, the test piece was pulled in a direction of 180 ° at a distance between marked lines of 50 mm and a speed of 50 mm / min, and the peel strength (N / 15 mm) of the test piece was measured. The peel strength of the test piece was measured within 10 minutes after the water on the surface of the test piece was wiped off with a towel. The strength when the distance between the marked lines reached 57 mm was defined as the peel strength of the test piece.

On the other hand, the initial adhesion was evaluated as follows. First, the exterior materials for each power storage device obtained above were cut into sizes of 15 mm (TD) and 100 mm (MD) to obtain test pieces. Next, the heat-sealing resin layer and the barrier layer of the test piece were peeled off, and the heat-sealing resin layer and the barrier layer were separated from each other by using a tensile tester (trade name AG-XPlus manufactured by Shimadzu Corporation). The test piece was pulled in a direction of 180 ° at a distance of 50 mm and a speed of 50 mm / min, and the peel strength (N / 15 mm) of the test piece was measured to determine the initial adhesion. The results are shown in Table 1. The peel strength in the initial adhesion is set to 100%, and the maintenance rate of the peel strength and the peel strength (after 24 hours) in the adhesion after immersion in the electrolytic solution are also shown in Table 1. When the heat-sealing resin layer and the barrier layer are peeled off, the adhesive layer located between these layers is laminated on either one or both of the heat-sealing resin layer and the barrier layer. It becomes.

<Measurement of hardness of each layer>
As an apparatus, a nanoindenter ((“ TriboIndenter TI950” manufactured by HYSITRON)) was used. As an indenter of the nanoindenter, a Berkovich indenter (triangular pyramid) was used. First, relative humidity was 50%, 23. In a ° C environment, the indenter is applied to the surface of the second adhesive layer of the exterior material for the power storage device (the surface where the second adhesive layer is exposed and is perpendicular to the stacking direction of each layer) for 10 seconds. The indenter was pushed into the adhesive layer from the surface to a load of 40 _{μN, held in that state for 5 seconds, and then unloaded over 10 seconds. Contact with the maximum load P max} (μN) at maximum depth. _{The indentation hardness (MPa) was calculated by P max} / A using the projected area A (μm ² ). The measurement points were changed, 5 points were measured, and the average value was used. The hardness was measured in the same manner as in the second adhesive layer except that the load was 10 μN. The hardness of each is shown in Table 1. The surface on which the indenter is pushed is the central portion of the exterior material for the power storage device. It is a portion where the cross section of the measurement target (second adhesive layer or the like) is exposed, which is obtained by cutting in the thickness direction so as to pass through. The cutting was performed using a commercially available rotary microtome or the like. In Comparative Examples 1 and 2, since the base material layer is one layer and the layer corresponding to the first adhesive layer does not exist, the measurement of the hardness of the adhesive layer is omitted, and Table 1 shows "-". It was shown by.

<Evaluation of moldability>
The exterior material for each power storage device obtained above was cut into a rectangle having a length (direction of MD (Machine Direction)) of 90 mm × width (direction of TD (Transverse Direction)) of 150 mm to prepare a test sample. This sample is used as a rectangular molding die with a diameter of 31.6 mm (MD direction) x 54.5 mm (TD direction) (female mold, surface is JIS B 0659-1: 2002 Annex 1 (reference)). The maximum height roughness (nominal value of Rz) specified in Table 2 of the comparative surface roughness standard piece is 3.2 μm. Corner R2.0 mm, ridge line R1.0 mm) and the corresponding molding die. Mold (male type, surface is JIS B 0659-1: 2002 Annex 1 (reference) Maximum height roughness (nominal value of Rz) specified in Table 2 of the comparative surface roughness standard piece is 1.6 μm. (Corner R2.0 mm, ridge line R1.0 mm), the forming depth is changed from 0.5 mm to 0.5 mm at a pressing pressure (surface pressure) of 0.25 MPa, and 10 pieces each. Cold forming (pull-in one-step forming) was performed on the sample of. At this time, the above test sample was placed on the female mold so that the heat-sealing resin layer side was located on the male mold side, and molding was performed. The clearance between the male type and the female type was set to 0.3 mm. The cold-formed sample was exposed to light with a penlight in a dark room, and it was confirmed whether or not pinholes or cracks were generated in the aluminum alloy foil due to the transmission of light. The deepest molding depth where pinholes and cracks do not occur in all 10 samples of the aluminum alloy foil is Amm, and the number of samples where pinholes etc. occur at the shallowest molding depth where pinholes etc. occur in the aluminum alloy foil. Was taken as B pieces, and the value calculated by the following formula was rounded to the second digit after the decimal point to obtain the limit molding depth of the exterior material for the power storage device. The results are shown in Table 1.
Limit molding depth = Amm + (0.5mm / 10 pieces) x (10 pieces-B pieces)

* Regarding the aging treatment conditions of Comparative Examples 1 and 2 shown in Table 1, the layer corresponding to the first adhesive layer does not exist in Comparative Examples 1 and 2, and the aging treatment conditions are the corrosion resistant film. The aging treatment (standing at 60 ° C. for 24 hours and then standing at 80 ° C. for 24 hours) was performed after laminating the adhesive layer on the barrier layer and the biaxially stretched nylon film side of the base material layer. It means the condition of).

The exterior materials for power storage devices of Examples 1 to 10 include at least a first base material layer, a first adhesive layer, a second base material layer, a second adhesive layer, a barrier layer, and a heat-sealing resin layer. It is composed of laminates prepared in this order, and a corrosion-resistant film is provided on the surface of at least one side of the barrier layer, and the time-of-flight secondary ion mass spectrometry is used for the corrosion-resistant film. when analyzed Te, CrPO ₄ ^- PO ₃ to the peak intensity P _CrPO4 derived from ^- the ratio of the peak intensity P _PO3 derived from P _{PO3 / CrPO4} is in the range of 6 to 120. As is clear from the results shown in Table 1, the exterior materials for power storage devices of Examples 1 to 10 maintain high adhesion of the barrier layer provided with the corrosion-resistant film even when the electrolytic solution adheres to them. , It was excellent in moldability. Among these, in the exterior materials for power storage devices of Examples 1 to 5, 8 to 10, the hardness of both the first adhesive layer and the second adhesive layer is set to 20 MPa or more, and the molding is particularly high. Had sex.

On the other hand, in Comparative Example 1, the peak intensity ratio P _{PO3 / CrPO4} was less than 6, the initial adhesion and the adhesion after immersion in the electrolytic solution were inferior to those of the Example, and the limit forming depth was 7 as well. It was less than .5 mm and was inferior in formability to the examples.

Further, also in Comparative Example 2, the peak intensity ratio P _{PO3 / CrPO4} exceeds 120, the adhesion after immersion in the electrolytic solution is inferior to that of the Example, and the limit forming depth is also less than 7.5 mm. It was inferior in moldability to the examples.

As described above, the present disclosure provides the inventions of the following aspects.
Item 1. It is composed of a laminate having at least a first base material layer, a first adhesive layer, a second base material layer, a second adhesive layer, a barrier layer, and a heat-sealing resin layer in this order.
A corrosion-resistant film is provided on the surface of at least one side of the barrier layer.
For the corrosion resistant coating, flight when analyzed with time-of secondary ion mass spectrometry, CrPO ₄ ^- PO ₃ to the peak intensity P _CrPO4 derived from ^- the ratio of the peak intensity P _PO3 derived from P _{PO3 / An} exterior material for a power storage device in which CrPO4 is in the range of 6 or more and 120 or less.
Item 2. The hardness of the first adhesive layer measured by the nanoindentation method is 20 MPa or more, and the hardness is 20 MPa or more.
Item 2. The exterior material for a power storage device according to Item 1, wherein the second adhesive layer has a hardness of 20 MPa or more as measured by a nanoindentation method.
Item 3. The first base material layer contains at least one of polyamide and polyester, and the first base material layer contains at least one of polyamide and polyester.
Item 2. The exterior material for a power storage device according to Item 1 or 2, wherein the second base material layer contains polyamide.
Item 4. The corrosion-resistant film is provided at least on the surface of the barrier layer on the heat-sealing resin layer side.
Item 2. The exterior material for a power storage device according to any one of Items 1 to 3, wherein the corrosion-resistant film and the heat-sealing resin layer are laminated via an adhesive layer.
Item 5. Item 2. The exterior material for a power storage device according to Item 4, wherein the resin constituting the adhesive layer has a polyolefin skeleton.
Item 6. Item 2. The exterior material for a power storage device according to Item 4 or 5, wherein the adhesive layer contains an acid-modified polyolefin.
Item 7. Item 6. The exterior material for a power storage device according to any one of Items 4 to 6, wherein a peak derived from maleic anhydride is detected when the adhesive layer is analyzed by infrared spectroscopy.
Item 8. The acid-modified polyolefin of the adhesive layer is maleic anhydride-modified polypropylene.
Item 6. The exterior material for a power storage device, wherein the heat-sealing resin layer contains polypropylene.
Item 9. At least, the first base material layer, the first adhesive layer, the second base material layer, the second adhesive layer, the barrier layer, and the heat-sealing resin layer are laminated in this order to obtain a laminated body. It has a process,
When laminating the barrier layer, a corrosion resistant film is provided on the surface of at least one side of the barrier layer.
The corrosion-resistant coating, flight when analyzed with time-of secondary ion mass spectrometry, CrPO ₄ ^- PO ₃ to the peak intensity P _CrPO4 derived from ^- the ratio of the peak intensity P _PO3 derived from P _{PO3 / CrPO4} However, a method for manufacturing an exterior material for a power storage device, which is within the range of 6 or more and 120 or less.
Item 10. A power storage device in which a power storage device element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the exterior material for the power storage device according to any one of Items 1 to 8.

10 Exterior material for power storage device 11 1st base material layer 12 2nd base material layer 21 1st adhesive layer 22 2nd adhesive layer 3 Barrier layer 4 Heat-sealing resin layer 5 Adhesive layer 6 Surface coating layer

Claims (10)

It is composed of a laminate having at least a first base material layer, a first adhesive layer, a second base material layer, a second adhesive layer, a barrier layer, and a heat-sealing resin layer in this order.
A corrosion-resistant film is provided on the surface of at least one side of the barrier layer.
For the corrosion resistant coating, flight when analyzed with time-of secondary ion mass spectrometry, CrPO ₄ ^- PO ₃ to the peak intensity P _CrPO4 derived from ^- the ratio of the peak intensity P _PO3 derived from P _{PO3 / An} exterior material for a power storage device in which CrPO4 is in the range of 6 or more and 120 or less. The hardness of the first adhesive layer measured by the nanoindentation method is 20 MPa or more, and the hardness is 20 MPa or more.
The exterior material for a power storage device according to claim 1, wherein the second adhesive layer has a hardness of 20 MPa or more as measured by a nanoindentation method. The first base material layer contains at least one of polyamide and polyester, and the first base material layer contains at least one of polyamide and polyester.
The exterior material for a power storage device according to claim 1 or 2, wherein the second base material layer contains polyamide. The corrosion-resistant film is provided at least on the surface of the barrier layer on the heat-sealing resin layer side.
The exterior material for a power storage device according to any one of claims 1 to 3, wherein the corrosion-resistant film and the heat-sealing resin layer are laminated via an adhesive layer. The exterior material for a power storage device according to claim 4, wherein the resin constituting the adhesive layer has a polyolefin skeleton. The exterior material for a power storage device according to claim 4 or 5, wherein the adhesive layer contains an acid-modified polyolefin. The exterior material for a power storage device according to any one of claims 4 to 6, wherein a peak derived from maleic anhydride is detected when the adhesive layer is analyzed by infrared spectroscopy. The acid-modified polyolefin of the adhesive layer is maleic anhydride-modified polypropylene.
The exterior material for a power storage device according to claim 6, wherein the heat-sealing resin layer contains polypropylene. At least, the first base material layer, the first adhesive layer, the second base material layer, the second adhesive layer, the barrier layer, and the heat-sealing resin layer are laminated in this order to obtain a laminated body. It has a process,
When laminating the barrier layer, a corrosion resistant film is provided on the surface of at least one side of the barrier layer.
The corrosion-resistant coating, flight when analyzed with time-of secondary ion mass spectrometry, CrPO ₄ ^- PO ₃ to the peak intensity P _CrPO4 derived from ^- the ratio of the peak intensity P _PO3 derived from P _{PO3 / CrPO4} However, a method for manufacturing an exterior material for a power storage device, which is within the range of 6 or more and 120 or less. A power storage device in which a power storage device element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the exterior material for the power storage device according to any one of claims 1 to 8.

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