Method for evaluating moisture permeability of outer package material for power storage devices, method for controlling quality of outer package material for power storage devices, outer package material for power storage devices, method for producing outer package material for power storage devices, method for producing power storage device, and moisture adsorption film

Abstract

Disclosed is a method for evaluating moisture permeability of an outer package material for power storage devices, the method comprising: a step for preparing an outer package material for power storage devices, the outer package material being composed of a laminate that includes at least a base material layer, a barrier layer, and a thermally fusible resin layer in this order from the outer side; a sealing step for sealing a moisture adsorption film in a package that is obtained by thermally fusing the thermally fusible resin layers to each other at a peripheral edge part of the outer package material for power storage devices; a step for placing the package, in which the moisture adsorption film is sealed, in an environment that includes moisture; and a moisture measurement step for measuring the amount of moisture absorbed by the moisture adsorption film in the package. The moisture adsorption film includes a porous layer.

Description

Method for evaluating moisture permeability of exterior material for power storage device, method for quality control of exterior material for power storage device, exterior material for power storage device, method for manufacturing exterior material for power storage device, method for manufacturing power storage device, and moisture adsorption film

[0001] The present disclosure relates to a method for evaluating the moisture permeability of an exterior material for an electricity storage device, a quality control method for an exterior material for an electricity storage device, an exterior material for an electricity storage device, a method for manufacturing an exterior material for an electricity storage device, a method for manufacturing an electricity storage device, and a moisture adsorption film.

[0002] Various types of electricity storage devices have been developed, and in all of them, exterior materials are essential components for sealing electricity storage device elements such as electrodes and electrolytes. Conventionally, metal exterior materials have been widely used as exterior materials for electricity storage devices.

[0003] Meanwhile, in recent years, with the increasing performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., there has been a demand for electricity storage devices to have a variety of shapes as well as to be thinner and lighter in weight. However, the metallic exterior materials for electricity storage devices that have been widely used in the past have the drawbacks of being difficult to keep up with the diversification of shapes and also having limitations on how much they can be made lighter.

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

[0005] In such an electrical storage device packaging material, the electrical storage device element is generally sealed with a packaging body formed by heat-sealing the heat-sealable resin layer around the periphery of the electrical storage device packaging material, thereby obtaining an electrical storage device in which the electrical storage device element is housed inside the electrical storage device packaging material.

[0006] Japanese Patent Application Laid-Open No. 2008-287971

[0007] In an electricity storage device using such a film-like electricity storage device packaging material, the heat-sealed portion between the heat-sealed resin layers at the peripheral edge of the packaging material for an electricity storage device has a path where no barrier layer is present and moisture can easily penetrate into the interior of the electricity storage device (i.e., a path in the heat-sealed portion between the heat-sealed resin layers of the packaging material for an electricity storage device, perpendicular to the thickness direction of the heat-sealed resin layers). If moisture penetrates into the interior of the electricity storage device from the heat-sealed portion, there is a problem that the performance of the electricity storage device will deteriorate.

[0008] For this reason, a method for evaluating the moisture permeability of an electrical storage device packaging material is required. One method for evaluating the moisture permeability of an electrical storage device packaging material is to seal an electrolyte solution in a package obtained by heat-sealing heat-sealable resin layers together at the periphery of the electrical storage device packaging material, leave the package in a humid environment for a predetermined time, and then measure the amount of moisture increase in the electrolyte solution in the package to evaluate the moisture permeability of the electrical storage device packaging material.

[0009] However, in this method, since the electrolytic solution is sealed in the electrical storage device packaging material, the heat-sealable resin layer absorbs the electrolytic solution and swells. Therefore, the moisture permeability evaluated for the electrical storage device packaging material is the moisture permeability of the heat-sealable resin layer swollen with the electrolytic solution. Such evaluation of moisture permeability may not be appropriate for evaluating the moisture permeability of electrical storage device packaging materials (e.g., packaging materials for all-solid-state batteries or semi-solid-state batteries) that do not use an electrolyte that swells the heat-sealable resin layer, such as an electrolytic solution.

[0010] Therefore, the inventors of the present disclosure have investigated a method for evaluating the moisture permeability of an electrical storage device packaging material, for example, by sealing a solid moisture absorbent in a package obtained by heat-sealing heat-sealable resin layers together at the periphery of the electrical storage device packaging material, leaving the package in a humid environment for a predetermined time, and then measuring the amount of moisture increase in the solid moisture absorbent. This method has the advantage of not having the problems associated with the method of sealing in an electrolyte solution.

[0011] However, after further investigation, the inventors of the present disclosure discovered a new problem: when considering the case where an electricity storage device element is vacuum-sealed in a package formed from an exterior material for an electricity storage device, there is a large variance in the measured values ​​of the moisture increase amount of the solid moisture absorbent, resulting in insufficient evaluation accuracy of the moisture permeability of the exterior material for an electricity storage device.

[0012] Under these circumstances, a main object of the present disclosure is to provide a novel method for evaluating the moisture permeability of an exterior material for an electricity storage device.

[0013] The inventors of the present disclosure conducted extensive research to solve the above-mentioned problems, and as a result, found that the moisture permeability of an electrical storage device packaging material can be evaluated with high accuracy by vacuum-sealing a moisture adsorption film including a porous layer in a package obtained by heat-sealing heat-sealable resin layers together at the periphery of the packaging material for an electrical storage device, placing the package in a moist environment, and measuring the amount of moisture absorbed by the moisture adsorption film in the package.

[0014] The present disclosure has been completed through further studies based on these findings. That is, the present disclosure provides the following aspects of the invention: A method for evaluating the moisture permeability of an electrical storage device packaging material, comprising: a step of preparing an electrical storage device packaging material composed of a laminate including, in order from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer; a sealing step of sealing a moisture adsorption film in a package obtained by heat-sealing the heat-sealable resin layers together at the periphery of the electrical storage device packaging material; a step of placing the package with the sealed moisture adsorption film in a moisture-containing environment; and a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the package, wherein the moisture adsorption film includes a porous layer.

[0015] According to the present disclosure, it is possible to provide a novel evaluation method capable of evaluating the moisture permeability of an electrical storage device packaging material with high accuracy. Furthermore, according to the present disclosure, it is also possible to provide a quality control method and a manufacturing method of an electrical storage device packaging material using the evaluation method, a manufacturing method of an electrical storage device, and a moisture adsorption film.

[0016] FIG. 1 is a schematic diagram showing an example of the cross-sectional structure of an exterior material for an electricity storage device according to the present disclosure. FIG. 1 is a schematic diagram showing an example of the cross-sectional structure of an exterior material for an electricity storage device according to the present disclosure. FIG. 1 is a schematic diagram showing an example of the cross-sectional structure of an exterior material for an electricity storage device according to the present disclosure. FIG. 2 is a schematic diagram for explaining a method of housing an electricity storage device element in a package formed from an exterior material for an electricity storage device according to the present disclosure. FIG. 3 is a schematic diagram for explaining a method of preparing a measurement sample (packaged body as a test subject) for evaluating moisture permeability in the examples. FIG. 2 is a perspective view of an example of an electricity storage device. FIG. 3 is a schematic diagram showing an example of the cross-sectional structure of a moisture adsorption film according to the present disclosure. FIG. 4 is a schematic diagram showing an example of the cross-sectional structure of a moisture adsorption film according to the present disclosure. FIG. 4 is a schematic diagram showing an example of the cross-sectional structure of a moisture adsorption film according to the present disclosure. FIG. 5 is a schematic diagram showing an example of the cross-sectional structure of a moisture adsorption film according to the present disclosure. FIG. 6 is a schematic diagram showing an example of the cross-sectional structure of a moisture adsorption film according to the present disclosure. 1 is a schematic diagram illustrating an example of a cross-sectional structure of an electricity storage device according to the present disclosure.

[0017] The method for evaluating the moisture permeability of an electrical storage device packaging material according to the present disclosure includes the steps of: preparing an electrical storage device packaging material composed of a laminate including, in order from the outside, at least a substrate layer, a barrier layer, and a heat-sealable resin layer; sealing a moisture adsorption film in a package obtained by heat-sealing the heat-sealable resin layers together at the periphery of the electrical storage device packaging material; placing the package with the moisture adsorption film sealed in a moisture-containing environment; and measuring the amount of moisture absorbed by the moisture adsorption film in the package, wherein the moisture adsorption film includes a porous layer. The method for evaluating moisture permeability according to the present disclosure is a novel method capable of evaluating the moisture permeability of electrical storage device packaging materials with high accuracy, and can be suitably used, for example, to evaluate the moisture permeability of electrical storage device packaging materials that do not use an electrolyte, such as an electrolyte solution, that swells the heat-sealable resin layer (e.g., packaging materials for all-solid-state batteries or packaging materials for semi-solid batteries).

[0018] The method for evaluating the moisture permeability of an electrical storage device packaging material, the quality control method for an electrical storage device packaging material, and the method for manufacturing an electrical storage device packaging material and an electrical storage device according to the present disclosure will be described in detail below.

[0019] In the present disclosure, a numerical range indicated by "to" means "greater than or equal to" or "less than or equal to." For example, the notation 2 to 15 mm means 2 mm or greater and 15 mm or less. In the numerical ranges described in stages in the present disclosure, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, separately described upper and lower limits, upper and lower limits, or lower and lower limits may each be combined to form a numerical range. Furthermore, in the numerical ranges described in the present disclosure, the upper or lower limit value described in a certain numerical range may be replaced with a value shown in the examples.

[0020] In the packaging material for an electricity storage device, the MD (machine direction) and TD (transverse direction) of the barrier layer 3 described below can usually be determined during the manufacturing process. For example, when the barrier layer 3 is made of a metal foil such as an aluminum alloy foil or a stainless steel foil, linear lines called rolling marks are formed on the surface of the metal foil in the rolling direction (RD) of the metal foil. Since the rolling marks extend along the rolling direction, the rolling direction of the metal foil can be determined by observing the surface of the metal foil. Furthermore, during the manufacturing process of a laminate, the MD of the laminate usually coincides with the RD of the metal foil. Therefore, the MD of the laminate can be determined by observing the surface of the metal foil of the laminate and identifying the rolling direction (RD) of the metal foil. Furthermore, since the TD of the laminate is perpendicular to the MD of the laminate, the TD of the laminate can also be identified.

[0021] Furthermore, when the MD of an electrical storage device packaging material cannot be determined due to rolling marks on a metal foil such as an aluminum alloy foil or a stainless steel foil, it can be determined by the following method. One method for determining the MD of an electrical storage device packaging material is to observe the cross section of the heat-sealable resin layer of the electrical storage device packaging material using an electron microscope to confirm the sea-island structure. In this method, the direction parallel to the cross section in which the average diameter of the island shapes in the direction perpendicular to the thickness direction of the heat-sealable resin layer is largest can be determined as the MD. Specifically, the sea-island structure is confirmed by observing, using an electron microscope, a cross section in the longitudinal direction of the heat-sealable resin layer and each cross section in a direction angled 10 degrees from the direction parallel to the longitudinal cross section (a total of 10 cross sections). Next, the shape of each individual island is observed in each cross section. For each island shape, the linear distance connecting the leftmost end in the direction perpendicular to the thickness direction of the heat-sealable resin layer to the rightmost end in the perpendicular direction is defined as the diameter y. For each cross section, the average of the 20 largest diameters y of the island shapes is calculated. The direction parallel to the cross section with the largest average diameter y of the island shapes is determined to be the MD.

[0022] In the present disclosure, an all-solid-state battery refers to a battery containing a solid electrolyte, and is a concept that includes not only batteries in which the electrolyte is entirely solid, but also semi-solid batteries, quasi-solid batteries, polymer batteries, and the like, and broadly encompasses batteries in which the barrier properties are not affected by the electrolyte being swelled in the heat-sealable resin layer.

[0023] 1. Method for Evaluating the Moisture Permeability of an Electricity Storage Device Exterior Material The method for evaluating the moisture permeability of an electricity storage device exterior material of the present disclosure can be used in the manufacturing process of an electricity storage device exterior material, the manufacturing process of an electricity storage device, etc. In the method for evaluating the moisture permeability of an electricity storage device exterior material of the present disclosure, the electricity storage device exterior material to be evaluated for moisture permeability is composed of a laminate including, from the outside, at least a base layer 1, a barrier layer 3, and a heat-sealable resin layer 4 (see FIGS. 1 to 4 ). The laminate structure of the electricity storage device exterior material and details of each layer will be described later.

[0024] The method for evaluating the moisture permeability of an electrical storage device packaging material according to the present disclosure includes a step of preparing an electrical storage device packaging material to be evaluated for moisture permeability. As described above, the electrical storage device packaging material to be evaluated is composed of a laminate including, in order from the outside, at least a base layer 1, a barrier layer 3, and a heat-sealable resin layer 4.

[0025] Next, a sealing step is performed in which the moisture adsorption film is sealed in the package obtained by heat-sealing the heat-fusible resin layers 4 together at the periphery of the packaging material for an electricity storage device. The moisture adsorption film is preferably vacuum-sealed. In the present disclosure, vacuum sealing refers to sealing (sealing) in a state in which the pressure inside the package is reduced to -50 kPa or less.

[0026] In the present disclosure, except that the moisture adsorption film includes a porous layer, the moisture adsorption characteristics (e.g., type of moisture adsorbent), size, etc. of the moisture adsorption film sealed in the package can be appropriately selected depending on the specific evaluation conditions for moisture permeability (shape and size of the package to be tested, measurement environment (temperature, humidity, etc. of the moisture-containing environment), measurement time, method for measuring the moisture permeation amount (e.g., Karl Fischer method, infrared spectroscopy, gravimetry, etc.)), moisture absorption amount (theoretical value) of the adsorbent contained in the moisture adsorption film, etc.

[0027] A moisture adsorption film is a film having moisture adsorption properties. In the moisture adsorption film of the present disclosure, for example, at least one of the layers contained in the moisture adsorption film contains a moisture absorbent, thereby enabling the moisture adsorption properties to be exhibited. In the present disclosure, a layer having moisture adsorption properties among the layers contained in the moisture adsorption film is referred to as a moisture adsorption layer. As described below, the moisture adsorption layer can be composed of, for example, a resin layer containing a moisture adsorbent.

[0028] In the present disclosure, the moisture adsorption film includes at least a porous layer. When the moisture adsorption film is composed only of a porous layer, the porous layer serves as the moisture adsorption layer. Furthermore, in the present disclosure, the moisture adsorption film may further include a moisture adsorption layer in addition to the porous layer. Examples of the configuration of the moisture adsorption film of the present disclosure include a single-layer porous layer (the porous layer serves as the moisture adsorption layer), a two-layer structure in which a porous layer and a moisture adsorption layer are laminated together, a three-layer structure in which a porous layer, a moisture adsorption layer, and a porous layer are laminated together in this order, a three-layer structure in which a porous layer, an adhesive layer, and a moisture adsorption layer are laminated together in this order, a five-layer structure in which a porous layer, an adhesive layer, a moisture adsorption layer, an adhesive layer, and a porous layer are laminated together in this order, and a three-layer structure in which a moisture adsorption layer, a porous layer, and a moisture adsorption layer are laminated together in this order. Thus, the moisture adsorption film may have a single-layer structure or a multi-layer structure.

[0029] When the moisture adsorption film is composed of a laminate of two or more layers, the layers may or may not be bonded to each other. For example, when the film has a two-layer structure in which a porous layer and a moisture adsorption layer are laminated, the porous layer and the moisture adsorption layer may not be bonded to each other, but may be independent sheets stacked on top of each other. Even in this case, the porous layer and the moisture adsorption layer are in contact with each other. Furthermore, when the layers are bonded to each other, they may be bonded via an adhesive layer, adhesive tape, or the like, or by heat fusion without an adhesive layer or adhesive tape.

[0030] Examples of layer structures of moisture adsorption films are shown in Figures 8 to 13 (each a schematic diagram showing an example of the cross-sectional structure of a moisture adsorption film). As shown in Figure 8, the moisture adsorption film 30 may be composed of only a porous layer 31. Alternatively, as shown in Figures 9 to 13, the moisture adsorption film 30 may include a moisture absorbing layer 32, an adhesive layer 33, and the like in addition to the porous layer 31. Figure 9 illustrates a layer structure in which the moisture adsorption film 30 is a laminate composed of two layers, a porous layer 31 and a moisture absorbing layer 32. Figure 10 illustrates a layer structure in which the moisture adsorption film 30 is a three-layer laminate composed of a porous layer 31, a moisture absorbing layer 32, and a porous layer 31 laminated in this order. Figure 11 illustrates a layer structure in which the moisture adsorption film 30 is a three-layer laminate composed of a moisture absorbing layer 32, a porous layer 31, and a moisture absorbing layer 32 laminated in this order. Figure 12 illustrates a layer structure in which the moisture adsorption film 30 is a three-layer laminate composed of a porous layer 31, an adhesive layer 33, and a moisture absorbing layer 32 laminated in this order. FIG. 13 illustrates a laminated structure of the moisture adsorption film 30, which is a five-layer laminate consisting of a porous layer 31, an adhesive layer 33, a moisture absorption layer 32, an adhesive layer 33, and a porous layer 31 laminated in this order.

[0031] When the moisture adsorption film 30 is a laminate including a porous layer 31 and a moisture absorbing layer 32, the thickness ratio of the porous layer 31 to the moisture absorbing layer 32 (thickness of the porous layer 31:thickness of the moisture absorbing layer 32) is preferably about 100:1 to 1:1, more preferably about 50:1 to 2:1, and even more preferably about 20:1 to 5:1. When there are two or more porous layers 31 and two or more moisture absorbing layers 32, the thickness ratio is the ratio of the total thickness of the porous layer 31 and the moisture absorbing layer 32.

[0032] In the method for evaluating moisture permeability according to the present disclosure, a moisture adsorption film is sealed in a package in the sealing step. The position at which the moisture adsorption film is sealed is not particularly limited as long as it is a position at which moisture permeability can be evaluated. For example, the moisture adsorption film may be disposed between the electricity storage device element and the package.

[0033] 14 and 15 , in the present disclosure, an electricity storage device 12 has a structure in which an electricity storage device element 13 is sealed in a packaging body formed from an exterior packaging material 10 for an electricity storage device. Metal terminals 15 protrude outside the packaging body. The metal terminals 15 are connected to the positive and negative electrodes of the electricity storage device element 13. An adhesive film 14 for metal terminals is disposed between the metal terminals 15 and the exterior packaging material 10, thereby enhancing adhesion between the metal terminals 15 and the heat-sealable resin layer 4 of the exterior packaging material 10. The electricity storage device 12 is sealed by covering the electricity storage device element 13 with the exterior packaging material 10 so that a flange portion (peripheral portion 10a of the exterior packaging material 10) of the exterior packaging material 10 can be formed around the periphery of the electricity storage device element 13, and then heat-sealing the flange portion of the exterior packaging material 10 to form a seal. When the exterior material 10 is used to house the electricity storage device element 13, the exterior material 10 is used with the heat-sealable resin layer 4 facing inside (the surface in contact with the electricity storage device element 13).

[0034] The moisture adsorption film 30 may be positioned, for example, on the entire surface of the packaging body formed from the exterior material 10 on the electricity storage device element 13 side (the heat-sealable resin layer 4 side), or on a part of the surface on the electricity storage device element 13 side (the heat-sealable resin layer 4 side). Also, for example, as shown in Fig. 14, the moisture adsorption film 30 may be disposed only between the electricity storage device exterior material 10 and the electricity storage device element 13, or as shown in Fig. 15, the moisture adsorption film 30 may cover the electricity storage device element 13.

[0035] When the moisture adsorption film 30 is located on the flange portion (peripheral edge portion 10a of the packaging material 10) of the packaging material 10, the moisture adsorption film 30 preferably has heat-sealing properties. The moisture adsorption film 30 may also have adhesive properties (pressure-sensitive adhesive properties), bonding properties, etc.

[0036] 14 and 15 show the electricity storage device 12 in which an embossed-type exterior material 10 formed by embossing or the like is used, the exterior material 10 may also be an unformed pouch-type exterior material. Pouch-type exterior materials include three-sided seal, four-sided seal, and pillow-type exterior materials, and any of these types may be used.

[0037] (Porous Layer) In the moisture adsorption film of the present disclosure, the porous layer is a layer provided to ensure a moisture permeation path through which the moisture adsorption film in the package absorbs moisture in the moisture permeability evaluation method of the present disclosure. Specifically, assuming a case in which an electricity storage device element is vacuum-sealed in a package formed from an exterior material for an electricity storage device, the presence of the porous layer ensures a moisture permeation path in the package, suppresses variation in the amount of moisture absorbed by the moisture adsorption film, and enables moisture permeability evaluation to be performed with high accuracy. The porous layer does not need to be moisture permeable as long as it can ensure a moisture permeation path, but it is preferable that it be moisture permeable. In addition, it is also preferable that the porous layer include communicating holes that communicate from one side of the layer to the other side.

[0038] The porous layer can be formed from a resin, a metal material, an inorganic oxide material, paper, or the like. The porous layer is preferably a porous resin layer formed from a resin. As the porous resin, for example, known materials such as foams and fibers made of resin can be used, and among these, foams are preferred. Porous resins are also readily available as commercial products.

[0039] When the porous layer is a resin foam, examples of the foaming agent used to foam the resin include organic and inorganic foaming agents. Examples of organic foaming agents include azo foaming agents such as azodicarbonamide (ADCA), azobisformamide, and azobisisobutyronitrile; fluorinated alkane foaming agents such as trichloromonofluoromethane; hydrazine foaming agents such as paratoluenesulfonylhydrazide; semicarbazide foaming agents such as p-toluenesulfonylsemicarbazide; triazole foaming agents such as 5-morpholyl-1,2,3,4-thiatriazole; and N-nitroso foaming agents such as N,N-dinitrosoterephthalamide. Examples of inorganic foaming agents include ammonium carbonate, ammonium bicarbonate, ammonium nitrite, ammonium borohydride, and azides. Alternatively, a microcapsule-type foaming agent may be used. Microcapsule-type foaming agents preferably have a core made of a thermal expansion agent such as a hydrocarbon and a shell made of a resin such as an acrylonitrile copolymer.

[0040] The foam has foam cells therein. The foam cells may be a mixture of open cells and closed cells. Open cells are preferred. The number, size, density, shape, etc. of the foam cells are not particularly limited and can be appropriately designed depending on the required performance of the moisture adsorption film of the present invention. The foam cells can be formed by foaming a foaming agent contained in a foaming-agent-containing resin composition used to form the foam.

[0041] The porous layer may be made of one kind of material or two or more kinds of materials.

[0042] Examples of resins that can be used to form the porous layer include thermoplastic resins and curable resins.

[0043] Examples of the thermoplastic resin include polyolefin, polyester, polyamide, acrylic resin, etc. The thermoplastic resin constituting the porous layer may be one type only, or two or more types.

[0044] As the resin constituting the porous layer, among thermoplastic resins, polyolefin, polyester, etc. are preferred.

[0045] Specific examples of polyolefins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; polypropylenes such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymers of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymers of propylene and ethylene); propylene-α-olefin copolymers; and ethylene-butene-propylene terpolymers. When the polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer. These polyolefin resins may be used alone or in combination of two or more. Among these, polyethylene and polypropylene are particularly preferred because of their excellent heat-fusion properties.

[0046] Specific examples of polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymer polyesters. Specific examples of copolymer polyesters include copolymer polyesters in which ethylene terephthalate is the main repeating unit. Specific examples include copolymer polyesters in which ethylene terephthalate is the main repeating unit and is polymerized with ethylene isophthalate (hereinafter abbreviated as polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate), and polyethylene (terephthalate / decanedicarboxylate). These polyesters may be used alone or in combination of two or more.

[0047] The curable resin refers to a resin that has curability, such as a thermosetting resin, an ionizing radiation curable resin, or an ultraviolet curable resin, and does not have a clear melting peak temperature after curing. Examples of the curable resin include urethane resin and epoxy resin. The porous layer may be made of only one type of curable resin, or two or more types of curable resins.

[0048] The thickness of the porous layer is not particularly limited as long as it can ensure a moisture permeation path in the vacuum-sealed package. From the viewpoint of suitably exhibiting the effects of the present disclosure, the thickness is preferably about 20 μm or more, more preferably about 100 μm or more, and even more preferably about 200 μm or more. Also, the thickness is preferably about 3000 μm or less, more preferably about 2000 μm or less, and even more preferably about 1000 μm or less. Preferred ranges include about 20 to 3000 μm, about 20 to 2000 μm, about 20 to 1000 μm, about 100 to 3000 μm, about 100 to 2000 μm, about 100 to 1000 μm, about 200 to 3000 μm, about 200 to 2000 μm, and about 200 to 1000 μm.

[0049] The basis weight (weight) of the porous layer is not particularly limited as long as it can secure a moisture permeation path in the vacuum-sealed package, and from the viewpoint of suitably exerting the effects of the present disclosure, it is preferably about 12 g / cm 2 More preferably, about 15 g / cm 2 More preferably, about 20 g / cm 2 The above are included, and preferably about 50 g / cm 2 or less, more preferably about 40 g / cm 2 More preferably, about 30 g / cm 2 The following can be mentioned, and the preferred range is 12 to 50 g / cm 2 Degree, 12-40g / cm 2 Degree, 12-30g / cm 2 Degree, 15-50g / cm 2 Degree, 15-40g / cm 2 Degree, 15-30g / cm 2 Degree, 20-50g / cm 2 Degree, 20-40g / cm2 Degree, 20-30g / cm 2 The degree of

[0050] (Moisture adsorption layer) As described above, when the moisture adsorption film of the present disclosure is composed only of a porous layer, the porous layer serves as the moisture adsorption layer. Furthermore, the moisture adsorption film of the present disclosure may further include a moisture adsorption layer in addition to the porous layer. Even when a moisture adsorption layer is provided in addition to the porous layer, the porous layer may also function as a moisture adsorption layer (i.e., a moisture adsorption layer). When the moisture adsorption film of the present disclosure includes a moisture adsorption layer in addition to the porous layer, it is preferable that the porous layer is not a moisture adsorption layer.

[0051] When the porous layer serves as the moisture adsorption layer, it is preferable that the porous layer contains a moisture adsorbent. When a moisture adsorption layer is provided in addition to the porous layer, a resin layer containing a moisture adsorbent can be used as the moisture adsorption layer.

[0052] In the present disclosure, the moisture to be absorbed by the moisture adsorption film is gaseous and / or liquid moisture.

[0053] Examples of the moisture adsorbent include solid moisture absorbents. The solid moisture absorbent is not particularly limited as long as it is a substance that has the property of absorbing moisture and is solid. For use in evaluating power storage devices, absorbents that can adsorb moisture under low humidity conditions, absorbents with a sufficiently large absorption weight relative to the absorbent weight, and adsorbents with little volume change are suitable. Specific examples of adsorbents include zeolite (e.g., molecular sieves), potassium carbonate, calcium chloride, calcium oxide, aluminum oxide, magnesium perchlorate, magnesium sulfate, sodium sulfate, silica gel, quicklime (calcium oxide), tetraphosphorus hexaoxide, magnesium oxide, zinc chloride, and the like. Only one type of solid moisture absorbent may be used, or two or more types may be used. Among these solid moisture absorbents, zeolite (e.g., molecular sieve), potassium carbonate, calcium chloride, calcium oxide, aluminum oxide, magnesium perchlorate, magnesium sulfate, and sodium sulfate are preferred, zeolite (e.g., molecular sieve), calcium oxide, potassium carbonate, and calcium chloride are more preferred, and zeolite (e.g., molecular sieve) and calcium oxide are particularly preferred. For example, the amount of moisture absorbed by zeolite (e.g., molecular sieve) can be measured by the Karl Fischer method, allowing measurement in a short time even for trace amounts of moisture absorption. Zeolite (e.g., molecular sieve) also has the advantage that the amount of moisture absorption does not change depending on the surrounding environment. Furthermore, the amount of moisture absorbed by calcium oxide can be measured by a near-infrared spectrometer (IR), allowing measurement in a short time even for trace amounts of moisture absorption.

[0054] For example, when zeolite (e.g., molecular sieves), magnesium perchlorate, potassium carbonate, silica gel, or the like is used as the solid moisture absorbent, the amount of moisture absorbed by the solid moisture absorbent in the moisture adsorption film can be measured by the Karl Fischer method in the moisture amount measurement step described below. In the present disclosure, the Karl Fischer method allows even a small amount of moisture absorbed by the solid moisture absorbent to be measured. Therefore, compared to, for example, a method of measuring the weight of moisture absorbed by a solid moisture absorbent in a moisture adsorption film in a package (which typically requires several tens of days or more), this method has the great advantage of being able to evaluate the moisture permeability of an electrical storage device exterior material in a short period of time (e.g., within one day). Furthermore, calcium oxide allows for measurement of even a small amount of moisture absorption in a short period of time using a near-infrared spectrometer (IR). Furthermore, since moisture is adsorbed by chemical adsorption, moisture is not re-released, making it suitable for evaluating electrical storage device exterior materials in a variety of predicted environments. For calcium chloride, quicklime (calcium oxide), tetraphosphate hexaoxide, magnesium oxide, potassium carbonate, zinc chloride, etc., a method can be used in which the weight of water absorbed by the solid moisture absorbent in the moisture adsorption film is measured.

[0055] In a moisture adsorption film, the solid moisture absorbent in the moisture adsorption layer can be dispersed in the resin of the moisture adsorption layer, or the solid moisture absorbent and resin can be mixed together. For example, when calcium oxide is in powder form, it is difficult to determine the amount to be measured during IR measurement. In the present disclosure, a resin layer in which calcium oxide is dispersed in a resin (e.g., a polyolefin resin layer in which calcium oxide is dispersed in a polyolefin such as polyethylene or polypropylene) is used as the moisture adsorption layer of the moisture adsorption film, and the moisture adsorption layer is used as the object to measure the moisture content, thereby improving the accuracy of IR measurement. For this reason, in the present disclosure, it is preferable to use a resin layer containing calcium oxide as the moisture adsorption layer.

[0056] Examples of resins that form the moisture adsorption layer include thermoplastic resins and curable resins.

[0057] Examples of thermoplastic resins include polyolefin, polyester, polyamide, acrylic resin, etc. The thermoplastic resin forming the moisture adsorption layer may be one type or two or more types.

[0058] As the resin for forming the moisture adsorption layer, from the viewpoint of water resistance and solvent resistance, polyolefin, polyester, etc. are preferred among thermoplastic resins.

[0059] Specific examples of polyolefins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; polypropylenes such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymers of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymers of propylene and ethylene); propylene-α-olefin copolymers; and ethylene-butene-propylene terpolymers. When the polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer. These polyolefin resins may be used alone or in combination of two or more. Among these, polyethylene and polypropylene are particularly preferred because of their excellent heat-fusion properties.

[0060] Specific examples of polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymer polyesters. Specific examples of copolymer polyesters include copolymer polyesters in which ethylene terephthalate is the main repeating unit. Specific examples include copolymer polyesters in which ethylene terephthalate is the main repeating unit and is polymerized with ethylene isophthalate (hereinafter abbreviated as polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate), and polyethylene (terephthalate / decanedicarboxylate). These polyesters may be used alone or in combination of two or more.

[0061] Examples of the curable resin include urethane resin, epoxy resin, etc. The moisture adsorption layer may be made of one type of curable resin or two or more types of curable resins.

[0062] The thickness of the moisture adsorption layer is not particularly limited as long as it exhibits moisture adsorption ability, and from the viewpoint of suitably exhibiting the effects of the present disclosure, it is preferably about 10 μm or more, more preferably about 20 μm or more, and even more preferably about 30 μm or more. It is also preferably about 300 μm or less, more preferably about 200 μm or less, and even more preferably about 100 μm or less. Preferred ranges include about 10 to 300 μm, about 20 to 300 μm, about 30 to 300 μm, about 10 to 200 μm, about 20 to 200 μm, about 30 to 200 μm, about 10 to 100 μm, about 20 to 100 μm, and about 30 to 100 μm.

[0063] From the viewpoint of optimally exerting the effects of the present disclosure, the overall thickness of the moisture adsorption film is preferably about 20 μm or more, more preferably about 30 μm or more, and even more preferably about 50 μm or more. Also, it is preferably about 3000 μm or less, more preferably about 2000 μm or less, and even more preferably about 1200 μm or less. Preferred ranges include about 20 to 3000 μm, about 20 to 2000 μm, about 20 to 1200 μm, about 30 to 3000 μm, about 30 to 2000 μm, about 30 to 1200 μm, about 50 to 3000 μm, about 50 to 2000 μm, and about 50 to 1200 μm.

[0064] The shape, size, and specific method of forming the heat-sealed portion of the package to be tested can be appropriately selected depending on the specific evaluation conditions for moisture permeability (measurement environment (temperature, humidity, etc. of the moisture-containing environment), measurement time, method of measuring the moisture permeation amount (e.g., Karl Fischer method, IR method, gravimetric measurement, etc.)), moisture absorption amount (theoretical value) of the moisture adsorption film, etc. Specific examples will be described in the Examples, but the package 11 to be tested can be prepared, for example, as follows.

[0065] (Example of Preparation of Package 11 to be Tested) The packaging material for an electricity storage device to be tested was prepared as a square sample measuring 120 mm in length (MD) x 120 mm in width (TD), and folded back in the MD at the center position P so that the heat-sealable resin layers faced each other ( FIG. 6a ). Next, the side facing the center position P (the horizontal direction (TD)) and the side perpendicular thereto (the vertical direction (MD)) were heat-sealed to heat-seal the heat-sealable resin layers, resulting in a bag-like sample with one side in the vertical direction (MD) open ( FIG. 6b ). As shown in FIG. 6b , the widths of the heat-sealed portions S formed by heat sealing were 7 mm (TD) and 10 mm (MD), respectively. A 7 mm-wide heat seal bar was used, and a single heat seal was performed in the TD direction to make the width of the heat-sealed portion S 7 mm. In addition, in the MD direction, a 7 mm wide heat seal bar is shifted and heat sealed twice so that the width of the heat-sealed portion S is 10 mm. In the MD direction, the center (4 mm wide) of the 10 mm wide heat-sealed portion S is heat-sealed twice. For the exterior packaging material A for electric storage devices, the heat sealing conditions for one side in the horizontal direction (TD direction) are a temperature of 190°C, a surface pressure of 1.0 MPa, and a time of 3 seconds. For the exterior packaging material B for electric storage devices, the heat sealing conditions for one side in the horizontal direction (TD direction) are a temperature of 240°C, a surface pressure of 1.0 MPa, and a time of 3 seconds. For the exterior packaging material B for electric storage devices, the heat sealing conditions for one side in the horizontal direction (TD direction) are a temperature of 240°C, a surface pressure of 1.0 MPa, and a time of 3 seconds. For the exterior packaging material B for electric storage devices, the heat sealing conditions for one side in the vertical direction (MD direction) are a temperature of 240°C, a surface pressure of 2.0 MPa, and a time of 3 seconds. Next, the bag-shaped sample was cut so that the width of the heat-sealed part on one side in the horizontal direction (TD) was 3 mm, and dried in a dry room for 24 hours ( Fig. 6c ). Next, a 20 mm × 20 mm moisture adsorption film A was inserted through the opening of the bag-shaped sample, and one side of the opening (longitudinal direction (MD)) was vacuum-sealed (approximately −100 kPa). The vacuum-sealed part was further heat-sealed in the same manner as the heat-sealed longitudinal direction (MD) side so that the width of the heat-sealed part S was 10 mm, to prepare a measurement sample (package 11 as the test subject) ( Fig. 6e ).

[0066] Next, a step is performed in which the package with the sealed moisture adsorption film is placed in a moisture-containing environment. In this step, moisture is absorbed into the moisture adsorption film in the package. There are no particular limitations on the moisture-containing environment (measurement environment), but a gas-phase environment with a temperature of 20 to 200°C and a relative humidity of 0.05% or more is preferred, and a gas-phase environment with a temperature of 20 to 85°C and a relative humidity of 20% or more is more preferred. The temperature is preferably 40 to 80°C, more preferably 40 to 65°C. The relative humidity is preferably 20% or more, more preferably 50% or more, and even more preferably 80% or more, with a preferred range being 80 to 95%.

[0067] Furthermore, the time (measurement time) for which the package as the test subject is placed in a moist environment (measurement environment) can also be adjusted as appropriate, for example, from 20 minutes to 6 weeks, preferably from 1 week to 16 weeks, and more preferably from 10 days to 4 weeks.

[0068] Next, a moisture amount measurement step is carried out to measure the amount of moisture absorbed by the moisture adsorption film in the package. There are no particular limitations on the method for measuring the amount of moisture absorbed by the moisture adsorption film, and any method can be selected as appropriate. Specific examples of methods for measuring the amount of moisture absorbed by the moisture adsorption film include the Karl Fischer method, near-infrared analysis, gravimetry, and gas chromatography-mass spectrometry.

[0069] When the moisture permeability coefficient from the heat-sealed portion between the heat-sealable resin layers 4 of the test package described above is calculated based on the amount of moisture absorbed by the moisture adsorption film, for example, if the measurement environment (moisture-containing environment) is a gas phase environment with a temperature of 35 to 65°C and a relative humidity of 85% or more, the moisture permeability coefficient is, for example, 10 g mm / m 2 / day or less, preferably 5 g mm / m 2 / day or less, more preferably 2 g mm / m 2 / day or less, more preferably 1 g mm / m 2 / day or less, the amount of moisture that permeates through the heat-sealed portions between the heat-sealable resin layers 4 of the packaging material for an electricity storage device is small, and it can be evaluated that the moisture permeability is low.

[0070] Furthermore, when the moisture permeability coefficient from the heat-sealed portion between the heat-sealable resin layers 4 of the test package is calculated based on the amount of moisture absorbed by the moisture adsorption film, for example, if the measurement environment (moisture-containing environment) is a gaseous environment with a temperature higher than 65°C and not higher than 90°C and a relative humidity of 85% or higher, the moisture permeability coefficient is, for example, 20 g mm / m 2 / day or less, preferably 18 g mm / m 2 / day or less, more preferably 16 g mm / m 2 / day or less, more preferably 15 g mm / m 2 / day or less, the amount of moisture that permeates through the heat-sealed portions between the heat-sealable resin layers 4 of the packaging material for an electricity storage device is small, and it can be evaluated that the moisture permeability is low.

[0071] 2. Quality Control Method for Electricity Storage Device Packaging Material The quality control method disclosed herein is a quality control method for an electricity storage device packaging material used in the manufacturing process of an electricity storage device packaging material or in the manufacturing process of an electricity storage device. In the quality control method disclosed herein, the electricity storage device packaging material that is the subject of quality control is composed of a laminate that includes, from the outside in order, at least a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4. The laminate structure of the electricity storage device packaging material and details of each layer will be described later.

[0072] The quality control method for an electrical storage device packaging material according to the present disclosure comprises the following steps: an extraction step of extracting an electrical storage device packaging material to be tested from the electrical storage device packaging materials, a sealing step of sealing a moisture adsorption film in a package to be tested obtained by heat-sealing the heat-sealable resin layers together at the periphery of the electrical storage device packaging material to be tested, a step of placing the package to be tested with the moisture adsorption film sealed in it in a moist environment, a moisture amount measurement step of measuring the amount of moisture absorbed by the moisture adsorption film in the package to be tested, and a determination step of determining whether the electrical storage device packaging material is a non-defective product based on the amount of moisture absorbed by the moisture adsorption film.

[0073] As mentioned above, the moisture absorbing film of the present disclosure includes a porous layer.

[0074] The quality control method of the present disclosure can be said to be a quality control method that utilizes the above-described method for evaluating the moisture permeability of an exterior material for an electricity storage device of the present disclosure, and among these steps, except for the inclusion of the "extraction step" and the "determination step," the quality control method overlaps with the steps described in the section "1. Method for evaluating the moisture permeability of an exterior material for an electricity storage device," and therefore, the description of the overlapping steps will be omitted as appropriate.

[0075] In the extraction step, a test exterior material for an electricity storage device is extracted from the exterior materials for an electricity storage device. When the quality control method of the present disclosure is used as part of a manufacturing process for an exterior material for an electricity storage device or a manufacturing process for an electricity storage device, the test exterior materials for an electricity storage device may be extracted randomly, or at a predetermined rate (for example, 1 in 1,000 to 10,000 exterior materials for an electricity storage device is extracted as the test exterior material for an electricity storage device), or all of the exterior materials for an electricity storage device may be extracted as the test exterior materials for an electricity storage device.

[0076] In the quality control method of the present disclosure, the "sealing step of sealing a moisture adsorption film in a test package obtained by heat-sealing the heat-fusible resin layers 4 together at the periphery of the testing packaging material for an electricity storage device," the "step of placing the testing packaging with the sealed moisture adsorption film in an environment containing moisture," and the "moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the testing packaging material" are each as explained above in the section "1. Method for evaluating the moisture permeability of an electricity storage device packaging material," and therefore further explanation will be omitted.

[0077] In the quality control method of the present disclosure, after the moisture amount measuring step, a "determining step of determining whether or not the packaging material for an electricity storage device is non-defective based on the amount of moisture absorbed by the moisture adsorption film" is carried out.

[0078] As described in the section "1. Method for evaluating the moisture permeability of packaging materials for power storage devices," when the moisture permeability coefficient from the heat-sealed portion between the heat-sealable resin layers 4 of the test package as described above is calculated based on the amount of moisture absorbed by the moisture adsorption film, for example, if the measurement environment (moisture-containing environment) is a gas phase environment with a temperature of 35 to 65°C and a relative humidity of 85% or more, the moisture permeability coefficient is, for example, 10 g mm / m2 / day or less, preferably 5 g mm / m 2 / day or less, more preferably 2 g mm / m 2 / day or less, more preferably 1 g mm / m 2 / day or less, the amount of moisture transmitted from the heat-sealed portion between the heat-sealed resin layers 4 of the packaging material for an electricity storage device is small, and it can be evaluated that the moisture permeability is low. Therefore, in the judgment step of the quality control method of the present disclosure, the moisture permeation coefficient from the heat-sealed portion between the heat-sealed resin layers 4 of the package to be tested is calculated based on the amount of moisture absorbed by the moisture adsorption film, and if the measurement environment (moisture-containing environment) is a gaseous environment with a temperature of 35 to 65°C and a relative humidity of 85% or more, for example, the moisture permeation coefficient can be evaluated as 10 g mm / m 2 In the determination step, the moisture permeability coefficient at which the electrical storage device packaging material can be determined to be a good product is preferably 5 g mm / m or less. 2 / day or less, more preferably 2 g mm / m 2 / day or less, more preferably 1 g mm / m 2 In addition, when the moisture permeability coefficient from the heat-sealed portion between the heat-sealable resin layers 4 of the test package is calculated based on the amount of moisture absorbed by the moisture adsorption film, for example, if the measurement environment (moisture-containing environment) is a gaseous environment with a temperature higher than 65°C and not higher than 90°C and a relative humidity of 85% or higher, the moisture permeability coefficient is, for example, 20 g mm / m 2 / day or less, preferably 18 g mm / m 2 / day or less, more preferably 16 g mm / m 2 / day or less, more preferably 15 g mm / m 2 / day or less, the amount of moisture that permeates through the heat-sealed portions between the heat-sealable resin layers 4 of the packaging material for an electricity storage device is small, and it can be evaluated that the moisture permeability is low.

[0079] 3. Manufacturing Method of Electricity Storage Device Exterior Material The manufacturing method of an electricity storage device exterior material of the present disclosure is a manufacturing method of an electricity storage device exterior material including a step of laminating, from the outside, at least a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4 in this order to obtain a laminate. The laminate structure and each layer of the electricity storage device exterior material will be described later in detail.

[0080] The method for manufacturing an electrical storage device packaging material according to the present disclosure comprises the following steps: a step of obtaining a laminate by laminating, from the outside in, at least a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4; an extraction step of extracting an electrical storage device packaging material to be tested from the laminate; a sealing step of sealing a moisture adsorption film in a package to be tested obtained by heat-sealing the heat-sealable resin layers 4 together at the periphery of the electrical storage device packaging material to be tested; a step of placing the package to be tested with the moisture adsorption film sealed in it in a moisture-containing environment; a moisture amount measurement step of measuring the amount of moisture absorbed by the moisture adsorption film in the package to be tested; and a determination step of determining whether the electrical storage device packaging material is non-defective based on the amount of moisture absorbed by the moisture adsorption film.

[0081] As mentioned above, the moisture absorbing film of the present disclosure includes a porous layer.

[0082] The manufacturing method for an electrical storage device exterior material according to the present disclosure can be said to be a manufacturing method for an electrical storage device exterior material that utilizes the above-described method for evaluating the moisture permeability of an electrical storage device exterior material according to the present disclosure, and among these steps, except for including "a step of laminating, from the outside, at least the base material layer 1, the barrier layer 3, and the heat-sealable resin layer 4 in this order to obtain a laminate," "an extraction step," and "a determination step," the steps overlap with the steps described in the section "1. Method for evaluating the moisture permeability of an electrical storage device exterior material," and therefore a description of the overlapping steps will be omitted.

[0083] Furthermore, the "extraction step" and "determination step" overlap with the steps explained in the section "2. Quality control method for packaging materials for electricity storage devices," and therefore explanations of these steps will also be omitted.

[0084] In the method for producing an exterior material for an electricity storage device according to the present disclosure, the step of laminating at least the base material layer 1, the barrier layer 3, and the heat-sealable resin layer 4 in this order from the outside to obtain a laminate is, for example, as follows.

[0085] First, a laminate (hereinafter, sometimes referred to as "laminate L") is formed in which the base layer 1, adhesive layer 2, and barrier layer 3 are laminated in this order. Specifically, the laminate L can be formed by a dry lamination method in which an adhesive used to form the adhesive layer 2 is applied to the base layer 1 or to the barrier layer 3, the surface of which has been chemically treated as necessary, by a coating method such as gravure coating or roll coating, and then dried, and the barrier layer 3 or base layer 1 is laminated thereon, and the adhesive layer 2 is cured.

[0086] Next, the heat-sealable resin layer 4 is laminated on the barrier layer 3 of the laminate L. When the heat-sealable resin layer 4 is laminated directly on the barrier layer 3, the heat-sealable resin layer 4 may be laminated on the barrier layer 3 of the laminate L by a method such as thermal lamination or extrusion lamination. When an adhesive layer 5 is provided between the barrier layer 3 and the heat-sealable resin layer 4, the adhesive layer 5 and the heat-sealable resin layer 4 may be laminated by, for example, (1) extrusion lamination, (2) thermal lamination, (3) sandwich lamination, or (4) dry lamination. Examples of the (1) extrusion lamination method include a method of laminating the adhesive layer 5 and the heat-sealable resin layer 4 on the barrier layer 3 of the laminate L by extrusion (co-extrusion lamination, tandem lamination), etc. Examples of the (2) thermal lamination method include a method of separately forming a laminate in which an adhesive layer 5 and a heat-sealable resin layer 4 are laminated, and laminating this on the barrier layer 3 of the laminate L, and a method of forming a laminate in which an adhesive layer 5 is laminated on the barrier layer 3 of the laminate L, and laminating this on the heat-sealable resin layer 4. Examples of the (3) sandwich lamination method include a method of pouring a molten adhesive layer 5 between the barrier layer 3 of the laminate L and a heat-sealable resin layer 4 that has been previously formed into a sheet, and bonding the laminate L and the heat-sealable resin layer 4 together via the adhesive layer 5. Examples of the (4) dry lamination method include a method of solution-coating an adhesive for forming the adhesive layer 5 on the barrier layer 3 of the laminate L, drying the adhesive, or baking the adhesive, and laminating the heat-sealable resin layer 4 that has been previously formed into a sheet on the adhesive layer 5.

[0087] When the surface coating layer 6 is provided, the surface coating layer 6 is laminated on the surface of the base layer 1 opposite to the barrier layer 3. The surface coating layer 6 can be formed, for example, by applying the above-mentioned resin for forming the surface coating layer 6 to the surface of the base layer 1. The order of the step of laminating the barrier layer 3 on the surface of the base layer 1 and the step of laminating the surface coating layer 6 on the surface of the base layer 1 is not particularly limited. For example, after the surface coating layer 6 is formed on the surface of the base layer 1, the barrier layer 3 may be formed on the surface of the base layer 1 opposite to the surface coating layer 6.

[0088] As described above, a laminate is formed which includes the optional surface coating layer 6 / substrate layer 1 / optional adhesive layer 2 / barrier layer 3 / optional adhesive layer 5 / thermally adhesive resin layer 4 in this order, and in order to strengthen the adhesion of the optional adhesive layer 2 and adhesive layer 5, the laminate may be further subjected to a heat treatment.

[0089] In the packaging material for an electricity storage device, each layer constituting the laminate may be subjected to a surface activation treatment such as corona treatment, blast treatment, oxidation treatment, ozone treatment, etc. as necessary to improve processability. For example, by subjecting the surface of the base layer 1 opposite to the barrier layer 3 to corona treatment, the printability of ink on the surface of the base layer 1 can be improved.

[0090] In this manner, a laminate is obtained by laminating at least the base layer 1, the barrier layer 3, and the heat-fusible resin layer 4 in this order from the outside.

[0091] 4. Manufacturing Method of Electricity Storage Device The manufacturing method of an electricity storage device according to the present disclosure is a manufacturing method of an electricity storage device in which an electricity storage device element is sealed with a packaging body formed by heat-sealing the heat-sealable resin layer 4 around the periphery of an exterior material 10 for an electricity storage device, which is composed of a laminate including, from the outside, at least a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4. The manufacturing method of an electricity storage device according to the present disclosure utilizes the evaluation method described in the section "1. Method for evaluating the moisture permeability of an exterior material for an electricity storage device" above in the manufacturing of an electricity storage device, and therefore, description of overlapping matters will be omitted as appropriate. As described above, the laminate structure and details of each layer of the exterior material for an electricity storage device will be described later.

[0092] The method for manufacturing an electricity storage device according to the present disclosure includes the following steps: An extraction step of extracting an electrical storage device packaging material to be tested from electrical storage device packaging materials; A sealing step of sealing a moisture adsorption film in a package to be tested obtained by heat-sealing the heat-sealable resin layers 4 together at the periphery of the electrical storage device packaging material to be tested; A step of placing the package to be tested with the moisture adsorption film sealed in it in a moist environment; A moisture amount measurement step of measuring the amount of moisture absorbed by the moisture adsorption film in the package to be tested; A determination step of determining whether the electrical storage device packaging material to be tested is non-defective based on the amount of moisture absorbed by the moisture adsorption film; A step of manufacturing an electricity storage device by housing an electrical storage device element in a package formed from the electrical storage device packaging material.

[0093] As mentioned above, the moisture absorbing film of the present disclosure includes a porous layer.

[0094] The manufacturing method for an electricity storage device according to the present disclosure can be said to be a manufacturing method for an electricity storage device that utilizes the above-described method for evaluating the moisture permeability of an exterior material for an electricity storage device according to the present disclosure. Of these steps, except for the inclusion of the "extraction step," the "determination step," and the "step of manufacturing an electricity storage device by housing an electricity storage device element in a packaging body formed from an exterior material for an electricity storage device," the manufacturing method for an electricity storage device overlaps with the steps described in the section "1. Method for evaluating the moisture permeability of an exterior material for an electricity storage device," and therefore a description of the overlapping steps will be omitted.

[0095] Furthermore, the "extraction step" and "determination step" overlap with the steps explained in the section "2. Quality control method for packaging materials for electricity storage devices," and therefore explanations of these steps will also be omitted.

[0096] In the manufacturing method of the present disclosure for an electricity storage device, if the result of the determination process indicates that the exterior material for the electricity storage device is a good product, an electricity storage device element is placed in a packaging body formed from the exterior material for the electricity storage device to manufacture the electricity storage device.

[0097] There are no particular restrictions on the specific method for the process of manufacturing an electricity storage device by housing an electricity storage device element in a packaging body formed from an exterior material for an electricity storage device, as long as the electricity storage device is sealed in the packaging body formed from the exterior material for an electricity storage device to form an electricity storage device.

[0098] For example, an electricity storage device using an electricity storage device packaging material is manufactured by covering an electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte with an electricity storage device packaging material such that a flange portion (a region where the heat-sealable resin layers 4 contact each other) is formed around the periphery of the electricity storage device element, with metal terminals connected to the positive electrode and the negative electrode protruding outward, and then heat-sealing the heat-sealable resin layers 4 of the flange portion to form a hermetic seal. When an electricity storage device element is housed in a package formed from an electricity storage device packaging material, the package is formed so that the heat-sealable resin portion of the electricity storage device packaging material of the present disclosure faces inward (the surface that contacts the electricity storage device element). The package may be formed by overlapping two electricity storage device packaging materials with the heat-sealable resin layers 4 facing each other and heat-sealing the peripheries of the overlapped electricity storage device packaging materials. Alternatively, as shown in the example of FIG. 5, a package may be formed by folding one electricity storage device packaging material over the other and heat-sealing the peripheries. When folding and stacking, as shown in the example of FIG. 5 , the edges other than the folded edge may be heat-sealed to form a three-sided package, or the edges may be folded to form a flange and sealed on all four sides. Alternatively, a heat-sealed portion may be formed by wrapping an electrical storage device exterior material around the electrical storage device element and sealing the heat-sealable resin layers together, and then a lid formed from a resin molded product, a metal molded product, an electrical storage device exterior material, or the like may be placed to close the openings at both ends, and then heat-sealed to the electrical storage device exterior material wrapped around the electrical storage device element. The lid can be formed, for example, from a resin molded product, a metal molded product, an electrical storage device exterior material, or a combination thereof. In the present disclosure, when a lid is referred to as a resin molded product, this does not include embodiments in which the lid is composed solely of a film as defined in JIS K6900-1994 [Plastics—Terminology]. When the lid is a metal molded product, the lid also functions as a metal terminal, so that the metal terminal can be omitted. The lid may be configured to contain a resin material and a conductive material. Furthermore, the exterior packaging material for an electricity storage device may have a recess for accommodating the electricity storage device element formed therein by deep drawing or bulging molding.As in the example shown in Fig. 5, one of the exterior materials for an electricity storage device may have a recess while the other exterior material for an electricity storage device does not, or a recess may also be provided in the exterior material for the other electricity storage device. Fig. 7 shows an example of an electricity storage device in which a recess is not provided in the exterior material for an electricity storage device. In the electricity storage device 12 of Fig. 7, the exterior material for an electricity storage device 50 is wrapped around the periphery of an electricity storage device element (which has a rectangular parallelepiped shape in Fig. 7) with the heat-sealable resin layer of the exterior material for an electricity storage device 50 facing inward, the heat-sealable resin layers are heat-sealed to form a heat-sealed portion, and a lid 60 is arranged to close the openings at both ends.

[0099] The manufactured electricity storage device can be suitably used as an electricity storage device including a battery (condenser, capacitor, etc.). The electricity storage device of the present disclosure may be either a primary battery or a secondary battery, but is preferably a secondary battery. The type of secondary battery is not particularly limited, and examples thereof include lithium ion batteries, lithium ion polymer batteries, all-solid-state batteries, semi-solid batteries, quasi-solid batteries, polymer batteries, all-resin batteries, lead-acid batteries, nickel-metal hydride batteries, nickel-cadmium batteries, nickel-iron batteries, nickel-zinc batteries, silver oxide-zinc batteries, metal-air batteries, polyvalent cation batteries, capacitors, and capacitors. Among these secondary batteries, examples of electricity storage devices include lithium ion batteries and lithium ion polymer batteries.

[0100] 1, the electrical storage device packaging material 10 is composed of a laminate including, in order from the outside, a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4. In the electrical storage device packaging material 10, the base material layer 1 is the outermost layer, and the heat-sealable resin layer 4 is the innermost layer. When assembling an electrical storage device using the electrical storage device packaging material 10 and an electrical storage device element, the electrical storage device element is housed in a space formed by heat-sealing the peripheral portions of the electrical storage device packaging material 10 with the heat-sealable resin layers 4 of the electrical storage device packaging material 10 facing each other. In the laminate constituting the electrical storage device packaging material 10 of the present disclosure, with the barrier layer 3 as the reference, the heat-sealable resin layer 4 side relative to the barrier layer 3 is the inner side, and the base material layer 1 side relative to the barrier layer 3 is the outer side.

[0101] The packaging material 10 for an electricity storage device according to the present disclosure may be composed of a laminate including, in this order, at least a barrier layer 3 and a heat-sealable resin layer 4. In the laminate, the base material layer 1 is a layer that is provided as needed, and the side of the barrier layer 3 opposite to the heat-sealable resin layer 4 side is the outermost layer, and the heat-sealable resin layer 4 is the innermost layer.

[0102] As shown in Figures 2 to 4, for example, the packaging material 10 for an electricity storage device may have an adhesive layer 2 between the base material layer 1 and the barrier layer 3, if necessary, for the purpose of increasing the adhesion between these layers. Furthermore, as shown in Figures 3 and 4, for example, the packaging material 10 may have an adhesive layer 5 between the barrier layer 3 and the heat-sealable resin layer 4, if necessary, for the purpose of increasing the adhesion between these layers. Furthermore, as shown in Figure 4, a surface coating layer 6 or the like may be provided on the outer side of the base material layer 1 (the side opposite to the heat-sealable resin layer 4 side), if necessary.

[0103] The thickness of the laminate constituting the electrical storage device exterior material 10 is not particularly limited, but from the viewpoint of cost reduction, improvement of energy density, etc., examples of the thickness include about 300 μm or less, preferably about 250 μm or less, about 210 μm or less, about 190 μm or less, about 180 μm or less, about 155 μm or less, and about 120 μm or less. Furthermore, from the viewpoint of maintaining the function of the electrical storage device exterior material to protect the electrical storage device elements, the thickness of the laminate constituting the electrical storage device exterior material 10 is preferably about 35 μm or more, about 45 μm or more, about 60 μm or more, about 155 μm or more, and about 190 μm or more. Furthermore, preferred ranges for the laminate constituting the exterior packaging material 10 for an electricity storage device are, for example, about 35 to 300 μm, about 35 to 250 μm, about 35 to 210 μm, about 35 to 190 μm, about 35 to 180 μm, about 35 to 155 μm, about 35 to 120 μm, about 45 to 300 μm, about 45 to 250 μm, about 45 to 210 μm, about 45 to 190 μm, about 45 to 180 μm, about 45 to 155 μm, about 45 to 120 μm, about 60 to 300 μm, about 60 to 250 μm, and about 60 to 300 μm. Examples of the thickness include about 210 μm, about 60 to 190 μm, about 60 to 180 μm, about 60 to 155 μm, about 60 to 120 μm, about 155 to 300 μm, about 155 to 250 μm, about 155 to 210 μm, about 155 to 190 μm, about 155 to 180 μm, about 190 to 300 μm, about 190 to 250 μm, and about 190 to 210 μm. In particular, when making the power storage device lightweight and thin, about 60 to 155 μm is preferred, and when improving formability, about 155 to 190 μm is preferred.

[0104] In the electrical storage device packaging material 10, the ratio of the total thickness of the base material layer 1, the adhesive layer 2 (which is provided as needed), the barrier layer 3, the adhesive layer 5 (which is provided as needed), the heat-sealable resin layer 4, and the surface coating layer 6 (which is provided as needed) to the thickness (total thickness) of the laminate constituting the electrical storage device packaging material 10 is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more. As a specific example, when the electrical storage device packaging material 10 of the present disclosure includes the base material layer 1, the adhesive layer 2, the barrier layer 3, the adhesive layer 5, and the heat-sealable resin layer 4, the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the electrical storage device packaging material 10 is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more. Furthermore, even when the electrical storage device packaging material 10 of the present disclosure is a laminate including a substrate layer 1, an adhesive layer 2, a barrier layer 3, and a heat-sealable resin layer 4, the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the electrical storage device packaging material 10 can be, for example, 80% or more, preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.

[0105] [Substrate layer 1] In the present disclosure, the substrate layer 1 is a layer provided for the purpose of exhibiting the function as a substrate of the packaging material for an electricity storage device, etc. The substrate layer 1 is located on the outer layer side of the packaging material for an electricity storage device.

[0106] There are no particular limitations on the material forming the substrate layer 1, as long as it functions as a substrate, i.e., has at least insulating properties. The substrate layer 1 can be formed using, for example, a resin, which may contain an additive described below.

[0107] When the substrate layer 1 is formed of a resin, the substrate layer 1 can be formed of, for example, a resin film. When the substrate layer 1 is formed of a resin film, a pre-formed resin film may be used as the substrate layer 1 when the substrate layer 1 is laminated with the barrier layer 3 or the like to produce the electrical storage device packaging material 10 of the present disclosure. Alternatively, the resin forming the substrate layer 1 may be formed into a film on the surface of the barrier layer 3 or the like by extrusion molding, coating, or the like to form the substrate layer 1 formed of a resin film. The resin film may be an unstretched film or a stretched film. Examples of stretched films include uniaxially stretched films and biaxially stretched films, with biaxially stretched films being preferred. Examples of stretching methods for forming a biaxially stretched film include sequential biaxial stretching, inflation, and simultaneous biaxial stretching. Examples of methods for applying the resin include roll coating, gravure coating, and extrusion coating.

[0108] Examples of resins that form the base layer 1 include polyester, polyamide, polyolefin, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, and phenolic resin, as well as modified versions of these resins. The resin that forms the base layer 1 may also be a copolymer of these resins, a modified version of the copolymer, or a mixture of these resins.

[0109] The base layer 1 preferably contains these resins as the main component, and more preferably contains polyester or polyamide as the main component. Here, "main component" means that the content of the resin component contained in the base layer 1 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more. For example, "the base layer 1 contains polyester or polyamide as the main component" means that the content of polyester or polyamide among the resin components contained in the base layer 1 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more.

[0110] Of these, polyester and polyamide are preferred as the resin for forming the base layer 1.

[0111] Specific examples of polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymer polyesters. Examples of copolymer polyesters include copolymer polyesters in which ethylene terephthalate is the main repeating unit. Specific examples include copolymer polyesters in which ethylene terephthalate is the main repeating unit and is polymerized with ethylene isophthalate (hereinafter abbreviated as polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate), and polyethylene (terephthalate / decanedicarboxylate). These polyesters may be used alone or in combination of two or more.

[0112] Specific examples of polyamides include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and copolymers of nylon 6 and nylon 66; hexamethylenediamine-isophthalic acid-terephthalic acid copolymer polyamides such as nylon 6I, nylon 6T, nylon 6IT, and nylon 6I6T (where I represents isophthalic acid and T represents terephthalic acid) containing structural units derived from terephthalic acid and / or isophthalic acid; and aromatic polyamides such as polyamide MXD6 (polymetaxylylene adipamide); alicyclic polyamides such as polyamide PACM6 (polybis(4-aminocyclohexyl)methane adipamide); polyamides copolymerized with a lactam component or an isocyanate component such as 4,4'-diphenylmethane-diisocyanate; polyesteramide copolymers and polyetheresteramide copolymers, which are copolymers of copolymerized polyamides with polyesters or polyalkylene ether glycols; and polyamides such as copolymers of these copolymers. These polyamides may be used alone or in combination of two or more.

[0113] The base layer 1 preferably includes at least one of a polyester film, a polyamide film, and a polyolefin film, and preferably includes at least one of a stretched polyester film, a stretched polyamide film, and a stretched polyolefin film, and more preferably includes at least one of a stretched polyethylene terephthalate film, a stretched polybutylene terephthalate film, a stretched nylon film, and a stretched polypropylene film, and even more preferably includes at least one of a biaxially oriented polyethylene terephthalate film, a biaxially oriented polybutylene terephthalate film, a biaxially oriented nylon film, and a biaxially oriented polypropylene film.

[0114] The base material layer 1 may be a single layer or may be composed of two or more layers. When the base material layer 1 is composed of two or more layers, the base material layer 1 may be a laminate in which resin films are laminated with an adhesive or the like, or a laminate of resin films formed by co-extrusion of resins into two or more layers. Furthermore, a laminate of resin films formed by co-extrusion of resins into two or more layers may be used as the base material layer 1 without being stretched, or may be uniaxially or biaxially stretched to form the base material layer 1.

[0115] Specific examples of the laminate of two or more resin films in the base layer 1 include a laminate of a polyester film and a nylon film, a laminate of two or more nylon films, and a laminate of two or more polyester films. A laminate of a stretched nylon film and a stretched polyester film, a laminate of two or more stretched nylon films, or a laminate of two or more stretched polyester films is preferred. For example, when the base layer 1 is a laminate of two resin films, a laminate of a polyester resin film and a polyester resin film, a laminate of a polyamide resin film and a polyamide resin film, or a laminate of a polyester resin film and a polyamide resin film is preferred. A laminate of a polyethylene terephthalate film and a polyethylene terephthalate film, a laminate of a nylon film and a nylon film, or a laminate of a polyethylene terephthalate film and a nylon film is more preferred. Furthermore, since polyester resins are less likely to discolor when an electrolytic solution adheres to their surface, it is preferred that the polyester resin film be located as the outermost layer of the base layer 1 when the base layer 1 is a laminate of two or more resin films. In the laminate of a polyester resin film and a polyamide resin film, preferred ranges of the thickness of the polyester resin film are about 2 to 33 μm, about 2 to 28 μm, about 2 to 23 μm, about 2 to 18 μm, about 2 to 11 μm, about 2 to 8 μm, about 10 to 33 μm, about 10 to 28 μm, about 10 to 23 μm, about 10 to 18 μm, about 18 to 33 μm, and about 18 to 28 μm. and about 18 to 23 μm. Preferred ranges of the thickness of the polyamide resin film include about 2 to 33 μm, about 2 to 28 μm, about 2 to 23 μm, about 2 to 18 μm, about 2 to 11 μm, about 2 to 8 μm, about 10 to 33 μm, about 10 to 28 μm, about 10 to 23 μm, about 10 to 18 μm, about 18 to 33 μm, about 18 to 28 μm, and about 18 to 23 μm.

[0116] When the base layer 1 is a laminate of two or more resin film layers, the two or more resin film layers may be laminated via an adhesive. Examples of preferred adhesives include those similar to those exemplified for adhesive layer 2 described below. The method for laminating two or more resin film layers is not particularly limited, and known methods can be used, such as dry lamination, sandwich lamination, extrusion lamination, and thermal lamination, with dry lamination being preferred. When laminating using the dry lamination method, it is preferable to use a polyurethane adhesive as the adhesive. In this case, the thickness of the adhesive may be, for example, about 2 to 5 μm. Alternatively, an anchor coat layer may be formed on the resin film before lamination. Examples of the anchor coat layer include those similar to those exemplified for adhesive layer 2 described below. In this case, the thickness of the anchor coat layer may be, for example, about 0.01 to 1.0 μm.

[0117] Furthermore, additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, antistatic agents, and colorants may be present on at least one of the surface and the interior of the base material layer 1. Only one type of additive may be used, or two or more types may be mixed and used.

[0118] In the present disclosure, from the viewpoint of improving the formability of the exterior material for an electrical storage device, it is preferable that a lubricant be present on at least one of the surface and the interior of the base material layer 1. The lubricant is not particularly limited, but preferably an amide-based lubricant is used. Specific examples of amide-based lubricants include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides. Specific examples of saturated fatty acid amides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide. Specific examples of unsaturated fatty acid amides include oleic acid amide and erucic acid amide. Specific examples of substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide. Specific examples of methylolamides include methylol stearic acid amide. Specific examples of saturated fatty acid bisamides include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipamide, N,N'-distearyl sebacic acid amide, etc. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipamide, N,N'-dioleyl sebacic acid amide, etc. Specific examples of fatty acid ester amides include stearamidoethyl stearate, etc. Specific examples of aromatic bisamides 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 kinds, and it is preferable to use a combination of two or more kinds.

[0119] When a lubricant is present on the surface of the base layer 1, the amount of the lubricant is not particularly limited, but may be, for example, about 3 mg / m 2 or more, preferably about 4 mg / m 2 Above, about 5mg / m 2 The amount of lubricant present on the surface of the base layer 1 is, for example, about 15 mg / m 2 or less, preferably about 14 mg / m 2 Below, about 10mg / m 2 The preferred range of the amount of lubricant present on the surface of the base layer 1 is 3 to 15 mg / m 2 Degree, 3-14mg / m 2 Degree, 3-10mg / m 2 Degree, 4-15mg / m 2 Degree, 4-14mg / m 2 degree, 4-10mg / m 2 degree, 5-15mg / m 2 Degree, 5-14mg / m 2 degree, 5-10mg / m 2 The degree of

[0120] The lubricant present on the surface of the base layer 1 may be a lubricant exuded from the resin constituting the base layer 1, or a lubricant applied to the surface of the base layer 1.

[0121] The thickness of the substrate layer 1 is not particularly limited as long as it functions as a substrate, but may be, for example, about 3 μm or more, preferably about 10 μm or more, and may be, for example, about 100 μm or less, about 90 μm or less, about 70 μm or less, or about 50 μm or less, preferably about 35 μm or less, 11 μm or less, or 8 μm or less. In addition, preferred ranges of the thickness of the base layer 1 include about 3 to 100 μm, about 3 to 90 μm, about 3 to 70 μm, about 3 to 50 μm, about 3 to 35 μm, about 3 to 11 μm, about 3 to 8 μm, about 10 to 100 μm, about 10 to 90 μm, about 10 to 70 μm, about 10 to 50 μm, about 10 to 35 μm, and about 10 to 11 μm. In particular, when making the power storage device lighter and thinner, about 3 to 35 μm, about 3 to 11 μm, and about 3 to 8 μm are preferred, and when improving formability, about 35 to 50 μm is preferred. When the base layer 1 is a laminate of two or more resin films, the thickness of the resin films constituting each layer is not particularly limited, but can be, for example, about 2 μm or more, preferably about 10 μm or more, or about 18 μm or more. The thickness of the resin film constituting each layer is, for example, about 33 μm or less, preferably about 28 μm or less, about 23 μm or less, about 18 μm or less, 11 μm or less, or 8 μm or less. Preferred ranges for the thickness of the resin film constituting each layer include about 2 to 33 μm, about 2 to 28 μm, about 2 to 23 μm, about 2 to 18 μm, about 2 to 11 μm, about 2 to 8 μm, about 10 to 33 μm, about 10 to 28 μm, about 10 to 23 μm, about 10 to 18 μm, about 18 to 33 μm, about 18 to 28 μm, and about 18 to 23 μm.

[0122] The base material layer 1 contains a colorant, which allows the electrical storage device packaging material to be colored. Known colorants such as pigments and dyes can be used as the colorant. Only one type of colorant may be used, or two or more types may be mixed together.

[0123] The type of pigment is not particularly limited as long as it does not impair the function as a substrate of the substrate layer 1. Examples of organic pigments include azo-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigothioindigo-based, perinone-perylene-based, isoindolenine-based, and benzimidazolone-based pigments, while examples of inorganic pigments include carbon black-based, titanium oxide-based, cadmium-based, lead-based, chromium oxide-based, and iron-based pigments, and other examples include finely powdered mica and fish scale foil.

[0124] Among colorants, carbon black is preferred for making the exterior material for an electricity storage device black, and mica is preferred from the viewpoint of dissipating heat generated from the electricity storage device.

[0125] The average particle size of the pigment is not particularly limited and may be, for example, about 0.03 to 5 μm, and preferably about 0.05 to 2 μm. The average particle size of the pigment is the median size measured with a laser diffraction / scattering particle size distribution analyzer.

[0126] The content of the colorant in the base layer 1 is not particularly limited as long as the packaging material for an electricity storage device is colored, and may be, for example, about 5 to 60 mass %, and preferably about 10 to 40 mass %.

[0127] [Adhesive Layer 2] In the packaging material for an electricity storage device according to the present disclosure, the adhesive layer 2 is a layer that is provided between the base layer 1 and the barrier layer 3 as needed for the purpose of increasing the adhesion between them.

[0128] The adhesive layer 2 is formed from an adhesive capable of bonding the base material layer 1 and the barrier layer 3. There are no limitations on the adhesive used to form the adhesive layer 2, and it may be any of a chemical reaction type, a solvent volatilization type, a hot melt type, a hot pressure type, etc. It may also be a two-component curing adhesive (two-component adhesive), a one-component curing adhesive (one-component adhesive), or a resin that does not involve a curing reaction. The adhesive layer 2 may be a single layer or multiple layers.

[0129] Specific examples of adhesive components contained in the adhesive include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymer polyesters; polyethers; polyurethanes; epoxy resins; phenolic resins; polyamides such as nylon 6, nylon 66, nylon 12, and copolymer polyamides; polyolefin-based resins such as polyolefins, cyclic polyolefins, acid-modified polyolefins, and acid-modified cyclic polyolefins; polyvinyl acetate; cellulose; (meth)acrylic resins; polyimides; polycarbonates; amino resins such as urea resins and melamine resins; rubbers such as chloroprene rubber, nitrile rubber, and styrene-butadiene rubber; and silicone resins. These adhesive components may be used alone or in combination with two or more. Among these adhesive components, polyurethane adhesives are preferred. Furthermore, the adhesive strength of these adhesive component resins can be increased by using an appropriate curing agent in combination. The curing agent is selected appropriately from polyisocyanates, multifunctional epoxy resins, oxazoline group-containing polymers, polyamine resins, acid anhydrides, and the like, depending on the functional groups possessed by the adhesive components.

[0130] Examples of polyurethane adhesives include polyurethane adhesives containing a first part containing a polyol compound and a second part containing an isocyanate compound. Two-component curing polyurethane adhesives are preferred, with a polyol such as polyester polyol, polyether polyol, or acrylic polyol as the first part and an aromatic or aliphatic polyisocyanate as the second part. Examples of polyurethane adhesives include polyurethane adhesives containing a polyurethane compound obtained by reacting a polyol compound with an isocyanate compound in advance, and an isocyanate compound. Examples of polyurethane adhesives include polyurethane adhesives containing a polyurethane compound obtained by reacting a polyol compound with an isocyanate compound in advance, and a polyol compound. Examples of polyurethane adhesives include polyurethane adhesives obtained by reacting a polyurethane compound obtained by reacting a polyol compound with an isocyanate compound in advance with moisture, such as in the air, and then curing the polyurethane compound. Polyester polyols having hydroxyl groups on the side chains in addition to terminal hydroxyl groups in the repeating unit are preferably used as the polyol compound. Examples of the second part include aliphatic, alicyclic, aromatic, and araliphatic isocyanate compounds. Examples of isocyanate compounds include hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and naphthalene diisocyanate (NDI). Also included are polyfunctional isocyanate-modified compounds of one or more of these diisocyanates. Multimers (e.g., trimers) can also be used as polyisocyanate compounds. Examples of such multimers include adducts, biurets, and nurates. Forming the adhesive layer 2 using a polyurethane adhesive provides the electrical storage device exterior material with excellent electrolyte resistance, preventing peeling of the base layer 1 even when the electrolyte adheres to the side surface.

[0131] Furthermore, the adhesive layer 2 may contain other components as long as they do not impair adhesion, and may contain colorants, thermoplastic elastomers, tackifiers, fillers, etc. By including a colorant in the adhesive layer 2, the electrical storage device packaging material can be colored. Known colorants such as pigments and dyes can be used as colorants. Furthermore, only one type of colorant may be used, or two or more types may be mixed together.

[0132] The type of pigment is not particularly limited as long as it does not impair the adhesiveness of the adhesive layer 2. Examples of organic pigments include azo-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigothioindigo-based, perinone-perylene-based, isoindolenine-based, and benzimidazolone-based pigments, while examples of inorganic pigments include carbon black-based, titanium oxide-based, cadmium-based, lead-based, chromium oxide-based, and iron-based pigments, and other examples include finely powdered mica and fish scale foil.

[0133] Among colorants, carbon black is preferred in order to give the exterior appearance of the electrical storage device packaging material a black color, for example.

[0134] The average particle size of the pigment is not particularly limited and may be, for example, about 0.03 to 5 μm, and preferably about 0.05 to 2 μm. The average particle size of the pigment is the median size measured with a laser diffraction / scattering particle size distribution analyzer.

[0135] The content of the colorant (pigment) in the adhesive layer 2 is not particularly limited as long as it colors the packaging material for an electricity storage device, and may be, for example, about 5 to 60 mass %, and preferably 10 to 40 mass %.

[0136] The thickness of the adhesive layer 2 is not particularly limited as long as it can bond the base layer 1 and the barrier layer 3, but is, for example, about 1 μm or more, about 2 μm or more. The thickness of the adhesive layer 2 is, for example, about 10 μm or less, about 5 μm or less. Preferred ranges for the thickness of the adhesive layer 2 include about 1 to 10 μm, about 1 to 5 μm, about 2 to 10 μm, and about 2 to 5 μm.

[0137] [Colored Layer] The colored layer is a layer (not shown) that is provided between the base material layer 1 and the barrier layer 3 as needed. When the adhesive layer 2 is provided, a colored layer may be provided between the base material layer 1 and the adhesive layer 2, or between the adhesive layer 2 and the barrier layer 3. Alternatively, a colored layer may be provided on the outside of the base material layer 1. By providing a colored layer, the packaging material for an electricity storage device can be colored.

[0138] The colored layer can be formed, for example, by applying ink containing a colorant to the surface of the base layer 1 or the surface of the barrier layer 3. Known colorants such as pigments and dyes can be used as the colorant. Only one type of colorant may be used, or two or more types may be mixed together.

[0139] Specific examples of the colorant contained in the colored layer include the same as those exemplified in the section [Adhesive layer 2].

[0140] [Barrier Layer 3] In the packaging material for an electricity storage device, the barrier layer 3 is a layer that at least prevents the penetration of moisture.

[0141] Examples of the barrier layer 3 include metal foils, vapor-deposited films, and resin layers having barrier properties. Vapor-deposited films include metal vapor-deposited films, inorganic oxide vapor-deposited films, and carbon-containing inorganic oxide vapor-deposited films. Resin layers include fluorine-containing resins such as polyvinylidene chloride, polymers mainly composed of chlorotrifluoroethylene (CTFE), polymers mainly composed of tetrafluoroethylene (TFE), polymers having fluoroalkyl groups, and polymers mainly composed of fluoroalkyl units, as well as ethylene-vinyl alcohol copolymers. Examples of the barrier layer 3 also include resin films comprising at least one of these vapor-deposited films and resin layers. The barrier layer 3 may include multiple layers. The barrier layer 3 preferably includes a layer composed of a metal material. Specific examples of metal materials constituting the barrier layer 3 include aluminum alloys, stainless steel, titanium steel, and steel plates. When used as a metal foil, the barrier layer 3 preferably includes at least one of aluminum alloy foil and stainless steel foil.

[0142] In the barrier layer 3, the layer made of the aforementioned metal material may contain recycled metal material. Examples of recycled metal material include recycled aluminum alloy, stainless steel, titanium steel, and steel plate. These recycled materials can be obtained by known methods. Recycled aluminum alloy material can be obtained, for example, by the manufacturing method described in International Publication No. 2022 / 092231. The barrier layer 3 may be made of recycled material alone, or may be made of a mixture of recycled and virgin material. Note that recycled metal material refers to metal material that has been made reusable by collecting, isolating, and refining various products used in the market or waste from manufacturing processes. Furthermore, virgin metal material refers to new metal material refined from natural metal resources (raw materials) and is not recycled material.

[0143] From the viewpoint of improving the formability of the electrical storage device packaging material, the aluminum alloy foil is preferably a soft aluminum alloy foil made of, for example, an annealed aluminum alloy, and from the viewpoint of further improving formability, an iron-containing aluminum alloy foil is preferred. In the iron-containing aluminum alloy foil (100% by mass), the iron content is preferably 0.1 to 9.0% by mass, more preferably 0.5 to 2.0% by mass. By having an iron content of 0.1% by mass or more, an electrical storage device packaging material with better formability can be obtained. By having an iron content of 9.0% by mass or less, an electrical storage device packaging material with better flexibility can be obtained. Examples of soft aluminum alloy foils include aluminum alloy foils having a composition specified in JIS H4160:1994 A8021H-O, JIS H4160:1994 A8079H-O, JIS H4000:2014 A8021P-O, or JIS H4000:2014 A8079P-O. Silicon, magnesium, copper, manganese, etc. may be added as needed. Softening can be achieved by annealing or other methods.

[0144] Examples of the stainless steel foil include austenitic, ferritic, austenitic-ferritic, martensitic, and precipitation hardened stainless steel foils. From the viewpoint of providing an exterior material for an electricity storage device that has excellent formability, the stainless steel foil is preferably made of austenitic stainless steel.

[0145] Specific examples of austenitic stainless steels that form the stainless steel foil include SUS304, SUS301, and SUS316L, with SUS304 being particularly preferred.

[0146] In the case of a metal foil, the thickness of the barrier layer 3 should be sufficient to at least function as a barrier layer that prevents moisture penetration, and may be, for example, approximately 9 to 200 μm. The thickness of the barrier layer 3 is preferably approximately 85 μm or less, more preferably approximately 50 μm or less, even more preferably approximately 40 μm or less, and particularly preferably approximately 35 μm or less. The thickness of the barrier layer 3 is preferably approximately 10 μm or more, even more preferably approximately 20 μm or more, and more preferably approximately 25 μm or more. Preferred thickness ranges for the barrier layer 3 include approximately 10 to 85 μm, approximately 10 to 50 μm, approximately 10 to 40 μm, approximately 10 to 35 μm, approximately 20 to 85 μm, approximately 20 to 50 μm, approximately 20 to 40 μm, approximately 20 to 35 μm, approximately 25 to 85 μm, approximately 25 to 50 μm, approximately 25 to 40 μm, and approximately 25 to 35 μm. When the barrier layer 3 is made of an aluminum alloy foil, the above-mentioned range is particularly preferable. From the viewpoint of imparting high formability and high rigidity to the packaging material 10 for an electricity storage device, the thickness of the barrier layer 3 is preferably about 35 μm or more, more preferably about 45 μm or more, even more preferably about 50 μm or more, and still more preferably about 55 μm or more, and is also preferably about 200 μm or less, more preferably about 85 μm or less, even more preferably about 75 μm or less, and still more preferably about 70 μm or less. Preferred ranges are approximately 35 to 200 μm, approximately 35 to 85 μm, approximately 35 to 75 μm, approximately 35 to 70 μm, approximately 45 to 200 μm, approximately 45 to 85 μm, approximately 45 to 75 μm, approximately 45 to 70 μm, approximately 50 to 200 μm, approximately 50 to 85 μm, approximately 50 to 75 μm, approximately 50 to 70 μm, approximately 55 to 200 μm, approximately 55 to 85 μm, approximately 55 to 75 μm, and approximately 55 to 70 μm. The high formability of the exterior packaging material 10 for an electricity storage device facilitates deep drawing, which can contribute to increasing the capacity of the electricity storage device. Furthermore, while increasing the capacity of an electricity storage device increases the weight of the electricity storage device, the increased rigidity of the exterior packaging material 10 for an electricity storage device can contribute to high sealing performance of the electricity storage device.In particular, when the barrier layer 3 is composed of a stainless steel foil, the thickness of the stainless steel foil is preferably about 60 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, even more preferably about 30 μm or less, and particularly preferably about 25 μm or less. The thickness of the stainless steel foil is preferably about 10 μm or more, more preferably about 15 μm or more. Preferred ranges for the thickness of the stainless steel foil include about 10 to 60 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 30 μm, about 10 to 25 μm, about 15 to 60 μm, about 15 to 50 μm, about 15 to 40 μm, about 15 to 30 μm, and about 15 to 25 μm.

[0147] Furthermore, when the barrier layer 3 is a metal foil, it is preferable that a corrosion-resistant coating be provided on at least the surface opposite the substrate layer to prevent dissolution and corrosion. The barrier layer 3 may be provided with a corrosion-resistant coating on both sides. Here, the corrosion-resistant coating refers to a thin film that is provided with corrosion resistance (e.g., acid resistance, alkali resistance, etc.) by performing, for example, a hydrothermal conversion treatment such as boehmite treatment, a chemical conversion treatment, an anodizing treatment, a plating treatment of nickel or chromium, or a corrosion prevention treatment by applying a coating agent on the surface of the barrier layer. Specifically, the corrosion-resistant coating refers to a coating that improves the acid resistance of the barrier layer (acid-resistant coating), a coating that improves the alkali resistance of the barrier layer (alkali-resistant coating), etc. The treatment for forming the corrosion-resistant coating may be one type or a combination of two or more types. Furthermore, not only one layer but also multiple layers can be formed. Furthermore, among these treatments, the hydrothermal conversion treatment and the anodizing treatment are treatments that dissolve the metal foil surface with a treatment agent to form a metal compound with excellent corrosion resistance. These treatments may be included in the definition of chemical conversion treatment. In addition, when the barrier layer 3 is provided with a corrosion-resistant coating, the barrier layer 3 includes the corrosion-resistant coating.

[0148] The corrosion-resistant coating prevents delamination between the barrier layer (e.g., aluminum alloy foil) and the substrate layer during molding of the electrical storage device packaging material, prevents dissolution and corrosion of the barrier layer surface due to hydrogen fluoride produced by a reaction between the electrolyte and water, and in particular prevents dissolution and corrosion of aluminum oxide present on the barrier layer surface when the barrier layer is an aluminum alloy foil, and also improves the adhesion (wettability) of the barrier layer surface, thereby preventing delamination between the substrate layer and the barrier layer during heat sealing and molding.

[0149] Various corrosion-resistant coatings formed by chemical conversion treatments are known, including mainly corrosion-resistant coatings containing at least one of phosphates, chromates, fluorides, triazine thiol compounds, and rare earth oxides. Examples of chemical conversion treatments using phosphates and chromates include chromate chromate treatment, phosphate chromate treatment, phosphate-chromate treatment, and chromate treatment. Examples of chromium compounds used in these treatments include chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, chromate acetylacetate, chromium chloride, and potassium chromium sulfate. Examples of phosphorus compounds used in these treatments include sodium phosphate, potassium phosphate, ammonium phosphate, and polyphosphoric acid. Examples of chromate treatments include etching chromate treatment, electrolytic chromate treatment, and paint-on chromate treatment, with paint-on chromate treatment being preferred. This paint-type chromate treatment involves first degreasing at least the inner surface of a barrier layer (e.g., an aluminum alloy foil) using a well-known method such as alkali immersion, electrolytic cleaning, acid pickling, electrolytic pickling, or acid activation, and then coating the degreased surface with a treatment solution containing, as its main component, a metal phosphate such as chromium (Cr) phosphate, titanium (Ti) phosphate, zirconium (Zr) phosphate, or zinc (Zn) phosphate, or a mixture of these metal salts, or a treatment solution containing, as its main component, a nonmetallic phosphate and a mixture of these nonmetallic salts, or a mixture of these with a synthetic resin, by a well-known coating method such as roll coating, gravure printing, or immersion, followed by drying. The treatment solution can be, for example, water, alcoholic solvents, hydrocarbon solvents, ketone solvents, ester solvents, or ether solvents, with water being preferred. Examples of the resin component used here include polymers such as phenolic resins and acrylic resins, and chromate treatment using an aminated phenol polymer having repeating units represented by the following general formulas (1) to (4). The aminated phenol polymer may contain one type of repeating unit represented by the following general formulas (1) to (4) alone, or two or more types of repeating units may be contained in any combination.The acrylic resin is preferably polyacrylic acid, an acrylic acid methacrylic acid ester copolymer, an acrylic acid maleic acid copolymer, an acrylic acid styrene copolymer, or a derivative thereof such as a sodium salt, an ammonium salt, or an amine salt. A derivative of polyacrylic acid, such as an ammonium salt, a sodium salt, or an amine salt of polyacrylic acid, is particularly preferred. In the present disclosure, polyacrylic acid refers to a polymer of acrylic acid. The acrylic resin is also preferably a copolymer of acrylic acid and a dicarboxylic acid or a dicarboxylic acid anhydride, or an ammonium salt, a sodium salt, or an amine salt of a copolymer of acrylic acid and a dicarboxylic acid or a dicarboxylic acid anhydride. Only one type of acrylic resin may be used, or two or more types may be mixed and used.

[0150]

[0151]

[0152]

[0153]

[0154] In the general formulas (1) to (4), X represents a hydrogen atom, a hydroxy group, an alkyl group, a hydroxyalkyl group, an allyl group, or a benzyl group. 1 and R 2 are the same or different and represent a hydroxy group, an alkyl group, or a hydroxyalkyl group. 1 and R 2 Examples of the alkyl group represented by X and R include linear or branched alkyl groups having 1 to 4 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl. 1 and R 2Examples of the hydroxyalkyl group represented by the formula (1) include a linear or branched alkyl group having 1 to 4 carbon atoms substituted with one hydroxy group, such as a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, a 3-hydroxypropyl group, a 1-hydroxybutyl group, a 2-hydroxybutyl group, a 3-hydroxybutyl group, and a 4-hydroxybutyl group. 1 and R 2 The alkyl group and hydroxyalkyl group represented by the formula (1) may be the same or different. In the formulae (1) to (4), X is preferably a hydrogen atom, a hydroxy group, or a hydroxyalkyl group. The number average molecular weight of the aminated phenol polymer having repeating units represented by the formulae (1) to (4) is preferably about 500 to 1,000,000, for example, and more preferably about 1,000 to 20,000. The aminated phenol polymer can be prepared, for example, by polycondensing a phenol compound or a naphthol compound with formaldehyde to produce a polymer comprising repeating units represented by the formula (1) or (3), and then polycondensing the polymer with formaldehyde and an amine (R 1 R 2 NH) to form a functional group (-CHNR 1 R 2 The aminated phenol polymers may be used singly or in combination of two or more.

[0155] Another example of a corrosion-resistant coating is a thin film formed by a coating-type corrosion prevention treatment in which a coating agent containing at least one selected from the group consisting of a rare earth element oxide sol, an anionic polymer, and a cationic polymer is applied. The coating agent may further contain phosphoric acid or a phosphate salt, and a crosslinking agent for crosslinking the polymer. The rare earth element oxide sol contains rare earth element oxide fine particles (e.g., particles with an average particle size of 100 nm or less) dispersed in a liquid dispersion medium. Examples of rare earth element oxides include cerium oxide, yttrium oxide, neodymium oxide, and lanthanum oxide, with cerium oxide being preferred from the perspective of further improving adhesion. The rare earth element oxide contained in the corrosion-resistant coating can be used alone or in combination of two or more. Examples of liquid dispersion media for the rare earth element oxide sol include various solvents such as water, alcohol-based solvents, hydrocarbon-based solvents, ketone-based solvents, ester-based solvents, and ether-based solvents, with water being preferred. Preferred examples of cationic polymers include polyethyleneimine, ionic polymer complexes consisting of polyethyleneimine and a polymer having a carboxylic acid, primary amine-grafted acrylic resins in which a primary amine is graft-polymerized onto an acrylic backbone, polyallylamine or its derivatives, and aminated phenols. Preferred anionic polymers include poly(meth)acrylic acid or its salts, or copolymers primarily composed of (meth)acrylic acid or its salts. The crosslinking agent is preferably at least one selected from the group consisting of a compound having a functional group selected from an isocyanate group, a glycidyl group, a carboxyl group, or an oxazoline group, and a silane coupling agent. The phosphoric acid or phosphoric acid salt is preferably a condensed phosphoric acid or a condensed phosphate salt.

[0156] An example of a corrosion-resistant coating is one formed by applying a solution in which fine particles of a metal oxide such as aluminum oxide, titanium oxide, cerium oxide, or tin oxide, or barium sulfate are dispersed in phosphoric acid to the surface of a barrier layer and then baking the coating at 150°C or higher.

[0157] The corrosion-resistant coating may have a laminated structure, if necessary, by further laminating at least one of a cationic polymer and an anionic polymer, such as those mentioned above.

[0158] The composition of the corrosion-resistant film can be analyzed by, for example, time-of-flight secondary ion mass spectrometry.

[0159] The amount of the corrosion-resistant film formed on the surface of the barrier layer 3 in the chemical conversion treatment is not particularly limited. For example, in the case of a coating-type chromate treatment, the amount of the corrosion-resistant film formed on the surface of the barrier layer 3 is 2 It is desirable that the chromate compound is contained in an amount, calculated as chromium, of about 0.5 to 50 mg, preferably about 1.0 to 40 mg, the phosphorus compound in an amount, calculated as phosphorus, of about 0.5 to 50 mg, preferably about 1.0 to 40 mg, and the aminated phenol polymer in an amount, calculated as phosphorus, of about 1.0 to 200 mg, preferably about 5.0 to 150 mg, per 1000 ml of the aqueous solution.

[0160] The thickness of the corrosion-resistant coating is not particularly limited, but is preferably about 1 nm to 20 μm, more preferably about 1 nm to 100 nm, and even more preferably about 1 nm to 50 nm, from the viewpoint of the cohesive strength of the coating and the adhesive strength with the barrier layer and the thermally adhesive resin layer. The thickness of the corrosion-resistant coating can be measured by observation with a transmission electron microscope, or by a combination of observation with a transmission electron microscope and energy dispersive X-ray spectroscopy or electron energy loss spectroscopy. Analysis of the composition of the corrosion-resistant coating using time-of-flight secondary ion mass spectrometry can reveal, for example, the thickness of the corrosion-resistant coating consisting of secondary ions of Ce, P, and O (e.g., Ce2PO4 + , CePO4 - or at least one of ions of Cr, P, and O (e.g., CrPO2 + , CrPO4 - Peaks derived from at least one of the above are detected.

[0161] The chemical conversion treatment is carried out by applying a solution containing a compound used to form a corrosion-resistant coating to the surface of the barrier layer by bar coating, roll coating, gravure coating, immersion, or the like, and then heating the barrier layer to a temperature of about 70 to 200°C. Furthermore, before applying the chemical conversion treatment to the barrier layer, the barrier layer may be subjected to a degreasing treatment using an alkali immersion method, electrolytic cleaning, acid cleaning, electrolytic acid cleaning, or the like. By performing such a degreasing treatment, the chemical conversion treatment of the surface of the barrier layer can be carried out more efficiently. Furthermore, by using an acid degreasing agent prepared by dissolving a fluorine-containing compound in an inorganic acid for the degreasing treatment, it is possible to not only degrease the metal foil but also form a fluoride of the metal, which is in a passive state. In such cases, only the degreasing treatment may be carried out.

[0162] [Heat-fusible resin layer 4] In the exterior packaging material for an electricity storage device of the present disclosure, the heat-fusible resin layer 4 corresponds to the innermost layer and is a layer (sealant layer) that exhibits the function of sealing the electricity storage device elements by heat-fusible resin layers being heat-fused together when the electricity storage device is assembled.

[0163] The resin constituting the heat-sealable resin layer 4 is not particularly limited as long as it is heat-sealable, but resins containing a polyolefin skeleton, such as polyolefin and acid-modified polyolefin, are preferred. The presence of a polyolefin skeleton in the resin constituting the heat-sealable resin layer 4 can be determined by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like. Furthermore, when the resin constituting the heat-sealable resin layer 4 is analyzed by infrared spectroscopy, a peak derived from maleic anhydride is preferably detected. For example, when maleic anhydride-modified polyolefin is measured by infrared spectroscopy, a peak derived from maleic anhydride is detected at a wavenumber of 1760 cm. -1 Nearby and wave number 1780 cm -1 A peak derived from maleic anhydride is detected around . When the thermally adhesive resin layer 4 is a layer made of maleic anhydride-modified polyolefin, a peak derived from maleic anhydride is detected by infrared spectroscopy. However, if the degree of acid modification is low, the peak becomes small and may not be detected. In such cases, analysis can be performed by nuclear magnetic resonance spectroscopy.

[0164] The heat-sealable resin layer 4 preferably contains a resin containing a polyolefin skeleton as a main component, more preferably a polyolefin as a main component, and even more preferably polypropylene as a main component. Here, "main component" refers to a resin component whose content of the resin components contained in the heat-sealable resin layer 4 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more. For example, "the heat-sealable resin layer 4 contains polypropylene as a main component" means that the polypropylene content of the resin components contained in the heat-sealable resin layer 4 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more.

[0165] Specific examples of polyolefins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; polypropylenes such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymers of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymers of propylene and ethylene); propylene-α-olefin copolymers; and ethylene-butene-propylene terpolymers. Among these, polypropylene is preferred. When the polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer. These polyolefin resins may be used alone or in combination of two or more.

[0166] The polyolefin may also be a cyclic polyolefin. Cyclic polyolefins are copolymers of olefins and cyclic monomers, and examples of olefins constituting the cyclic polyolefins include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. Examples of cyclic monomers constituting the cyclic polyolefins include cyclic alkenes such as norbornene; and cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these, cyclic alkenes are preferred, and norbornene is more preferred.

[0167] The polyolefin may also be an acid-modified polyolefin. An acid-modified polyolefin is a polymer modified by block polymerization or graft polymerization of a polyolefin with an acid component. Examples of the acid-modified polyolefin include the above-mentioned polyolefins, copolymers of the above-mentioned polyolefins with polar molecules such as acrylic acid or methacrylic acid, and polymers such as crosslinked polyolefins. Examples of the acid component used for acid modification include carboxylic acids or anhydrides thereof, such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride.

[0168] The acid-modified polyolefin may be an acid-modified cyclic polyolefin. The acid-modified cyclic polyolefin is a polymer obtained by copolymerizing a part of the monomers constituting the cyclic polyolefin by replacing it with an acid component, or by block polymerizing or graft polymerizing an acid component onto the cyclic polyolefin. The acid-modified cyclic polyolefin is the same as described above. The acid component used for the acid modification is the same as the acid component used for the modification of the polyolefin.

[0169] Preferred acid-modified polyolefins include polyolefins modified with carboxylic acid or its anhydride, polypropylenes modified with carboxylic acid or its anhydride, maleic anhydride-modified polyolefins, and maleic anhydride-modified polypropylenes.

[0170] The thermally adhesive resin layer 4 may be formed of one type of resin alone or a blend polymer of two or more types of resins. Furthermore, the thermally adhesive resin layer 4 may be formed of only one layer, or may be formed of two or more layers of the same or different resins.

[0171] When the thermally adhesive resin layer 4 is laminated with the barrier layer 3, the adhesive layer 5, or the like to produce the exterior packaging material 10 for an electricity storage device of the present disclosure, a pre-formed resin film may be used as the thermally adhesive resin layer 4. Alternatively, the thermally adhesive resin that forms the thermally adhesive resin layer 4 may be formed into a film on the surface of the barrier layer 3, the adhesive layer 5, or the like by extrusion molding, coating, or the like, to form the thermally adhesive resin layer 4 from a resin film.

[0172] Furthermore, the thermally adhesive resin layer 4 may contain a lubricant or the like as necessary. When the thermally adhesive resin layer 4 contains a lubricant, the formability of the electrical storage device packaging material can be improved. The lubricant is not particularly limited, and known lubricants can be used.

[0173] The lubricant is not particularly limited, but preferably an amide-based lubricant is used. Specific examples of the lubricant include those exemplified for the base layer 1. The lubricant may be used alone or in combination of two or more types, and a combination of two or more types is preferred.

[0174] In the present disclosure, from the viewpoint of improving the formability of the exterior material for an electrical storage device, it is preferable that a lubricant be present on at least one of the surface and the interior of the heat-sealable resin layer 4. The lubricant is not particularly limited, but preferably an amide-based lubricant is used. Specific examples of amide-based lubricants include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides. Specific examples of saturated fatty acid amides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide. Specific examples of unsaturated fatty acid amides include oleic acid amide and erucic acid amide. Specific examples of substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide. Specific examples of methylolamides include methylol stearic acid amide. Specific examples of saturated fatty acid bisamides include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipamide, N,N'-distearyl sebacic acid amide, etc. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipamide, N,N'-dioleyl sebacic acid amide, etc. Specific examples of fatty acid ester amides include stearamidoethyl stearate, etc. Specific examples of aromatic bisamides 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 kinds, and it is preferable to use a combination of two or more kinds.

[0175] When a lubricant is present on the surface of the heat-sealable resin layer 4, the amount of the lubricant is not particularly limited. However, from the viewpoint of improving the formability of the exterior material for an electrical storage device, the amount of the lubricant is preferably about 1 mg / m 2 or more, more preferably about 3 mg / m 2 or more, more preferably about 5 mg / m 2 or more, more preferably about 10 mg / m 2 or more, more preferably about 15 mg / m 2 or more, and preferably about 50 mg / m 2 or less, more preferably about 40 mg / m 2 The preferred range is 1 to 50 mg / m 2 Degree, 1-40mg / m 2 Degree, 3-50mg / m 2 Degree, 3-40mg / m 2 degree, 5-50mg / m 2 degree, 5-40mg / m 2 degree, 10-50mg / m 2 degree, 10-40mg / m 2 degree, 15-50mg / m 2 degree, 15-40mg / m 2 The degree of

[0176] When a lubricant is present inside the heat-sealable resin layer 4, the amount thereof is not particularly limited, but from the viewpoint of improving the formability of the packaging material for an electrical storage device, it is preferably about 100 ppm or more, more preferably about 300 ppm or more, and even more preferably about 500 ppm or more, and is preferably about 3000 ppm or less, more preferably about 2000 ppm or less, and preferred ranges include about 100 to 3000 ppm, about 100 to 2000 ppm, about 300 to 3000 ppm, about 300 to 2000 ppm, about 500 to 3000 ppm, and about 500 to 2000 ppm. When two or more types of lubricant are present inside the heat-sealable resin layer 4, the above amount of lubricant is the total amount of lubricant. Furthermore, when two or more types of lubricants are present inside the heat-sealable resin layer 4, the amount of the first type of lubricant present is not particularly limited, but from the viewpoint of improving the formability of the exterior material for an electrical storage device, it is preferably about 100 ppm or more, more preferably about 300 ppm or more, even more preferably about 500 ppm or more, and is preferably about 3000 ppm or less, more preferably about 2000 ppm or less, and preferred ranges include about 100 to 3000 ppm, about 100 to 2000 ppm, about 300 to 3000 ppm, about 300 to 2000 ppm, about 500 to 3000 ppm, and about 500 to 2000 ppm. The amount of the second type of lubricant present is not particularly limited, but from the viewpoint of improving the formability of the exterior material for an electricity storage device, it is preferably about 50 ppm or more, more preferably about 100 ppm or more, and even more preferably about 200 ppm or more, and is preferably about 1500 ppm or less, more preferably about 1000 ppm or less, and preferred ranges include about 50 to 1500 ppm, about 50 to 1000 ppm, about 100 to 1500 ppm, about 100 to 1000 ppm, about 200 to 1500 ppm, and about 200 to 1000 ppm.

[0177] The lubricant present on the surface of the heat-sealable resin layer 4 may be a lubricant exuded from the resin constituting the heat-sealable resin layer 4, or a lubricant applied to the surface of the heat-sealable resin layer 4.

[0178] The thickness of the heat-sealable resin layer 4 is not particularly limited as long as it functions to heat-seal the heat-sealable resin layers to each other and seal the electricity storage device element, but may be, for example, about 100 μm or less, preferably about 85 μm or less, and more preferably about 15 to 85 μm. Note that, for example, when the thickness of the adhesive layer 5 described below is 10 μm or more, the thickness of the heat-sealable resin layer 4 is preferably about 85 μm or less, more preferably about 15 to 45 μm. For example, when the thickness of the adhesive layer 5 described below is less than 10 μm or when the adhesive layer 5 is not provided, the thickness of the heat-sealable resin layer 4 is preferably about 20 μm or more, more preferably about 35 to 85 μm.

[0179] [Adhesive Layer 5] In the packaging material for an electricity storage device according to the present disclosure, the adhesive layer 5 is a layer that is provided as needed between the barrier layer 3 (or the corrosion-resistant coating) and the heat-sealable resin layer 4 in order to firmly bond them together.

[0180] The adhesive layer 5 is formed of a resin that can bond the barrier layer 3 and the heat-sealable resin layer 4. As the resin used to form the adhesive layer 5, for example, the same adhesive as exemplified for the adhesive layer 2 can be used.

[0181] Furthermore, from the viewpoint of firmly bonding the adhesive layer 5 and the heat-sealable resin layer 4, the resin used to form the adhesive layer 5 preferably contains a polyolefin skeleton, and examples thereof include the polyolefins, acid-modified polyolefins, cyclic polyolefins, and acid-modified cyclic polyolefins exemplified for the heat-sealable resin layer 4 described above. On the other hand, from the viewpoint of firmly bonding the barrier layer 3 and the adhesive layer 5, the adhesive layer 5 preferably contains an acid-modified polyolefin. Examples of acid-modified components include dicarboxylic acids such as maleic acid, itaconic acid, succinic acid, and adipic acid, as well as anhydrides thereof, acrylic acid, and methacrylic acid. However, from the viewpoint of ease of modification and versatility, maleic anhydride is most preferred. From the viewpoint of the heat resistance of the electrical storage device exterior material, the olefin component is preferably a polypropylene-based resin, and the adhesive layer 5 most preferably contains maleic anhydride-modified polypropylene.

[0182] When the resin used to form the adhesive layer 5 contains a polyolefin skeleton, the adhesive layer 5 preferably contains a resin containing a polyolefin skeleton as a main component, more preferably an acid-modified polyolefin as a main component, and even more preferably an acid-modified polypropylene as a main component. Here, "main component" means that the content of the resin component contained in the adhesive layer 5 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more. For example, when the adhesive layer 5 contains acid-modified polypropylene as a main component, it means that the content of acid-modified polypropylene among the resin components contained in the adhesive layer 5 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more.

[0183] The presence of a polyolefin skeleton in the resin constituting the adhesive layer 5 can be determined by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like, and the analysis method is not particularly limited. Furthermore, the presence of an acid-modified polyolefin in the resin constituting the adhesive layer 5 can be determined by, for example, measuring a maleic anhydride-modified polyolefin by infrared spectroscopy, and finding a wave number of 1760 cm -1 Nearby and wave number 1780 cm -1 A peak derived from maleic anhydride is detected around this point. However, if the degree of acid modification is low, the peak may be small and not be detected. In this case, analysis can be performed using nuclear magnetic resonance spectroscopy.

[0184] Furthermore, from the viewpoint of ensuring durability such as heat resistance and resistance to contents of the electrical storage device packaging material, and of ensuring moldability while reducing the thickness, the adhesive layer 5 is more preferably a cured product of a resin composition containing an acid-modified polyolefin and a curing agent. Preferred examples of the acid-modified polyolefin include those described above.

[0185] The adhesive layer 5 is preferably 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. 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 and a compound having an epoxy group is particularly preferred. 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. Examples of polyesters include ester resins formed by the reaction of epoxy groups with maleic anhydride groups, and amide ester resins formed by the reaction of oxazoline groups with maleic anhydride groups. If unreacted curing agents such as compounds having an isocyanate group, compounds having an oxazoline group, or epoxy resins remain in the adhesive layer 5, the presence of the unreacted materials can be confirmed by a method selected from the group consisting of infrared spectroscopy, Raman spectroscopy, time-of-flight secondary ion mass spectrometry (TOF-SIMS), and the like.

[0186] Furthermore, from the viewpoint of further enhancing the adhesion between the barrier layer 3 and the adhesive layer 5, the adhesive layer 5 is preferably a cured product of a resin composition containing a curing agent having at least one selected from the group consisting of an oxygen atom, a heterocycle, a C═N bond, and a C—O—C bond. Examples of curing agents having a heterocycle include curing agents having an oxazoline group and curing agents having an epoxy group. Examples of curing agents having a C═N bond include curing agents having an oxazoline group and curing agents having an isocyanate group. Examples of curing agents having a C—O—C bond include curing agents having an oxazoline group and curing agents having an epoxy group. Whether the adhesive layer 5 is a cured product of a resin composition containing such a curing agent can be confirmed by, for example, gas chromatography mass spectrometry (GCMS), infrared spectroscopy (IR), time-of-flight secondary ion mass spectrometry (TOF-SIMS), X-ray photoelectron spectroscopy (XPS), or other methods.

[0187] The compound having an isocyanate group is not particularly limited, but from the viewpoint of effectively increasing the adhesion between the barrier layer 3 and the adhesive layer 5, a polyfunctional isocyanate compound is preferably used. The polyfunctional isocyanate compound is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of polyfunctional isocyanate curing agents include pentane diisocyanate (PDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymers or nurates thereof, mixtures of these, and copolymers with other polymers. Other examples include adducts, biurets, and isocyanurates.

[0188] The content of the compound having an isocyanate group in the adhesive layer 5 is preferably in the range of 0.1 to 50 mass %, and more preferably in the range of 0.5 to 40 mass %, of the resin composition constituting the adhesive layer 5. This makes it possible to effectively improve the adhesion between the barrier layer 3 and the adhesive layer 5.

[0189] 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.

[0190] The proportion of the compound having an oxazoline group in the adhesive layer 5 is preferably in the range of 0.1 to 50 mass %, and more preferably in the range of 0.5 to 40 mass %, in the resin composition constituting the adhesive layer 5. This makes it possible to effectively improve the adhesion between the barrier layer 3 and the adhesive layer 5.

[0191] Examples of compounds having epoxy groups include epoxy resins. The epoxy resin is not particularly limited as long as it is a resin capable of forming a crosslinked structure by the epoxy groups present in the molecule, and known epoxy resins can be used. The weight-average molecular weight of the epoxy resin is preferably about 50 to 2,000, more preferably about 100 to 1,000, and even more preferably about 200 to 800. In the present disclosure, the weight-average molecular weight of the epoxy resin is a value measured by gel permeation chromatography (GPC) under conditions using polystyrene as a standard sample.

[0192] Specific examples of epoxy resins include glycidyl ether derivatives of trimethylolpropane, bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, bisphenol F glycidyl ether, novolac glycidyl ether, glycerin polyglycidyl ether, polyglycerin polyglycidyl ether, etc. The epoxy resins may be used alone or in combination of two or more.

[0193] The proportion of the epoxy resin in the adhesive layer 5 is preferably in the range of 0.1 to 50 mass %, and more preferably in the range of 0.5 to 40 mass %, of the resin composition constituting the adhesive layer 5. This makes it possible to effectively improve the adhesion between the barrier layer 3 and the adhesive layer 5.

[0194] The polyurethane is not particularly limited, and any known polyurethane can be used. The adhesive layer 5 may be, for example, a cured product of two-component curing polyurethane.

[0195] The proportion of polyurethane in the adhesive layer 5 is preferably in the range of 0.1 to 50 mass %, and more preferably in the range of 0.5 to 40 mass %, of the resin composition constituting the adhesive layer 5. This makes it possible to effectively improve the adhesion between the barrier layer 3 and the adhesive layer 5 in an atmosphere containing a component that induces corrosion of the barrier layer, such as an electrolyte solution.

[0196] In addition, 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 the 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.

[0197] The adhesive layer 5 may contain a modifier having a carbodiimide group.

[0198] When the adhesive layer 5 is laminated with the barrier layer 3, the heat-sealable resin layer 4, or the like to produce the packaging material for an electricity storage device 10 of the present disclosure, a pre-formed resin film may be used as the adhesive layer 5. Alternatively, the heat-sealable resin that forms the adhesive layer 5 may be formed into a film on the surface of the barrier layer 3, the heat-sealable resin layer 4, or the like by extrusion molding, coating, or the like, to form the adhesive layer 5 from a resin film.

[0199] 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, or about 5 μm or less. The thickness of the adhesive layer 5 is preferably about 0.1 μm or more, or about 0.5 μm or more. The thickness of the adhesive layer 5 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, about 0.1 to 5 μm, about 0.5 to 50 μm, about 0.5 to 40 μm, about 0.5 to 30 μm, about 0.5 to 20 μm, or about 0.5 to 5 μm. More specifically, in the case of adhesives such as those exemplified for the adhesive layer 2 or a cured product of an acid-modified polyolefin and a curing agent, the thickness is preferably about 1 to 10 μm, more preferably about 1 to 5 μm. Furthermore, when a resin exemplified for the heat-fusible resin layer 4 is used, the thickness is preferably about 2 to 50 μm, more preferably about 10 to 40 μm. When the adhesive layer 5 is an adhesive exemplified for the adhesive layer 2 or a cured product of a resin composition containing an acid-modified polyolefin and a curing agent, the adhesive layer 5 can be formed, for example, by applying the resin composition and curing it by heating or the like. When a resin exemplified for the heat-fusible resin layer 4 is used, the heat-fusible resin layer 4 and the adhesive layer 5 can be formed, for example, by extrusion molding.

[0200] [Surface Coating Layer 6] The packaging material for an electricity storage device according to the present disclosure may, if necessary, have a surface coating layer 6 on the substrate layer 1 (the side of the substrate layer 1 opposite to the barrier layer 3) for the purpose of improving at least one of design, electrolyte resistance, scratch resistance, formability, etc. The surface coating layer 6 is a layer located on the outermost layer side of the packaging material for an electricity storage device when an electricity storage device is assembled using the packaging material for an electricity storage device.

[0201] The surface coating layer 6 may be made of, for example, a resin such as polyvinylidene chloride, polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, or phenolic resin, or a modified version of these resins. It may also be a copolymer of these resins or a modified version of the copolymer. It may also be a mixture of these resins. The resin is preferably a curable resin. That is, the surface coating layer 6 is preferably made of a cured product of a resin composition containing a curable resin.

[0202] When the resin forming the surface coating layer 6 is a curable resin, the resin may be either a one-component curable resin or a two-component curable resin, but is preferably a two-component curable resin. Examples of two-component curable resins include two-component curable polyurethane, two-component curable polyester, and two-component curable epoxy resin. Among these, two-component curable polyurethane is preferred.

[0203] Examples of two-component curing polyurethanes include polyurethanes containing a first component containing a polyol compound and a second component containing an isocyanate compound. Preferred examples of two-component curing polyurethanes include those containing a polyol, such as polyester polyol, polyether polyol, or acrylic polyol, as the first component and an aromatic or aliphatic polyisocyanate as the second component. Examples of polyurethanes include polyurethanes containing an isocyanate compound and a polyurethane compound obtained by reacting a polyol compound with an isocyanate compound in advance. Examples of polyurethanes include polyurethanes containing a polyol compound and a polyurethane compound obtained by reacting a polyol compound with an isocyanate compound in advance. Examples of polyurethanes include polyurethanes obtained by reacting a polyol compound with an isocyanate compound in advance and then curing the polyurethane compound with moisture, such as in the air. Polyol compounds preferably include polyester polyols having hydroxyl groups on the side chains in addition to the terminal hydroxyl groups of the repeating units. Examples of second components include aliphatic, alicyclic, aromatic, and araliphatic isocyanate compounds. Examples of isocyanate compounds include hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and naphthalene diisocyanate (NDI). Also included are polyfunctional isocyanate-modified compounds of one or more of these diisocyanates. Furthermore, polymers (e.g., trimers) can also be used as polyisocyanate compounds. Examples of such polymers include adducts, biurets, and nurates. It should be noted that an aliphatic isocyanate compound refers to an isocyanate that has an aliphatic group but does not have an aromatic ring, an alicyclic isocyanate compound refers to an isocyanate that has an alicyclic hydrocarbon group, and an aromatic isocyanate compound refers to an isocyanate that has an aromatic ring.The surface coating layer 6 is formed from polyurethane, which provides the electrical storage device packaging material with excellent electrolyte resistance.

[0204] The surface coating layer 6 may contain additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, antistatic agents, and pigments, as necessary, in at least one of the surface and interior of the surface coating layer 6, depending on the functionality to be provided to the surface of the surface coating layer 6. Examples of additives include fine particles with an average particle size of approximately 0.5 nm to 5 μm. The average particle size of the additive is the median size measured with a laser diffraction / scattering particle size distribution analyzer.

[0205] The additive may be either inorganic or organic. The shape of the additive is not particularly limited, and examples thereof include spherical, fibrous, plate-like, amorphous, and scaly shapes.

[0206] Specific examples of additives include talc, silica, graphite, kaolin, montmorillonite, mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, carbon black, carbon nanotubes, high-melting-point nylon, acrylate resin, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, and nickel. The additives may be used alone or in combination of two or more. Among these additives, silica, barium sulfate, and titanium oxide are preferred from the viewpoints of dispersion stability and cost. The additives may also be subjected to various surface treatments, such as insulation treatment and high-dispersibility treatment.

[0207] The method for forming the surface coating layer 6 is not particularly limited, and examples thereof include a method of applying a resin to form the surface coating layer 6. When an additive is blended into the surface coating layer 6, a resin mixed with the additive may be applied.

[0208] In the present disclosure, from the viewpoint of improving the formability of the exterior material for an electrical storage device, it is preferable that a lubricant be present on at least one of the surface and the interior of the surface coating layer 6. The lubricant is not particularly limited, but preferably an amide-based lubricant is used. Specific examples of amide-based lubricants include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides. Specific examples of saturated fatty acid amides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide. Specific examples of unsaturated fatty acid amides include oleic acid amide and erucic acid amide. Specific examples of substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide. Specific examples of methylolamides include methylol stearic acid amide. Specific examples of saturated fatty acid bisamides include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipamide, N,N'-distearyl sebacic acid amide, etc. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipamide, N,N'-dioleyl sebacic acid amide, etc. Specific examples of fatty acid ester amides include stearamidoethyl stearate, etc. Specific examples of aromatic bisamides 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 kinds, and it is preferable to use a combination of two or more kinds.

[0209] When a lubricant is present on the surface of the surface coating layer 6, the amount of the lubricant is not particularly limited, but may be, for example, about 3 mg / m 2 or more, preferably about 4 mg / m 2 Above, about 5mg / m 2 The amount of lubricant present on the surface of the surface coating layer 6 is, for example, about 15 mg / m 2 or less, preferably about 14 mg / m 2 Below, about 10mg / m 2 The preferred range of the amount of lubricant present on the surface of the surface coating layer 6 is 3 to 15 mg / m 2 Degree, 3-14mg / m 2 Degree, 3-10mg / m 2 Degree, 4-15mg / m 2 Degree, 4-14mg / m 2 degree, 4-10mg / m 2 degree, 5-15mg / m 2 Degree, 5-14mg / m 2 degree, 5-10mg / m 2 The degree of

[0210] The lubricant present on the surface of the surface coating layer 6 may be a lubricant exuded from the resin that constitutes the surface coating layer 6, or a lubricant applied to the surface of the surface coating layer 6.

[0211] The surface coating layer 6 contains a colorant, which allows the electrical storage device exterior material to be colored. Known colorants such as pigments and dyes can be used as the colorant. Only one type of colorant may be used, or two or more types may be mixed together.

[0212] The type of pigment is not particularly limited, and examples of organic pigments include azo-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigothioindigo-based, perinone-perylene-based, isoindolenine-based, and benzimidazolone-based pigments. Examples of inorganic pigments include carbon black-based, titanium oxide-based, cadmium-based, lead-based, chromium oxide-based, and iron-based pigments. Other examples include finely powdered mica and fish scale foil.

[0213] Among colorants, carbon black is preferred for making the exterior material for an electricity storage device black, and mica is preferred from the viewpoint of dissipating heat generated from the electricity storage device.

[0214] The average particle size of the pigment is not particularly limited and may be, for example, about 0.03 to 5 μm, and preferably about 0.05 to 2 μm. The average particle size of the pigment is the median size measured with a laser diffraction / scattering particle size distribution analyzer.

[0215] The content of the colorant in the surface coating layer 6 is not particularly limited as long as the packaging material for an electricity storage device is colored, and may be, for example, about 5 to 60 mass %, and preferably about 10 to 40 mass %.

[0216] The thickness of the surface coating layer 6 is not particularly limited as long as the surface coating layer 6 exhibits the above-mentioned functions, and may be, for example, about 0.5 to 10 μm, and preferably about 1 to 5 μm.

[0217] 5. Packaging Material for Electricity Storage Device The present disclosure can also provide the following packaging material for an electricity storage device: A packaging material for an electricity storage device that is composed of a laminate including, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer, and that has a moisture permeability coefficient of 10 g mm / m or less calculated by a measurement method including the following steps: 2an electrical storage device packaging material, the electrical storage device packaging material having a moisture permeability of 10 ...

[0218] The laminated structure of the electrical storage device packaging material is as described above. The method for measuring the moisture permeability coefficient is also as described above. Specifically, the following method is applied as the method for measuring the moisture permeability coefficient.

[0219] (Preparation of moisture adsorption film) A CaO-containing polyethylene sheet (thickness: 50 μm) is prepared as the moisture adsorption layer of the moisture adsorption film. In addition, a foam sheet (thickness: 1 mm, basis weight: 24.5 g / cm) is prepared as the porous layer of the moisture adsorption film. 2 The moisture adsorption layer and the porous layer are stacked together to form a moisture adsorption film. After stacking the moisture adsorption layer and the porous layer, the four corners may be fixed with tape or the like so as not to affect the measurement results.

[0220] (Preparation of Test Package) The test packaging material for an electricity storage device was prepared as a square sample measuring 120 mm in length (MD) x 120 mm in width (TD), and folded back in the MD at the center position P so that the heat-sealable resin layers faced each other ( FIG. 6a ). Next, the heat-sealable resin layers were heat-sealed along one side (horizontal direction (TD)) facing the center position P and along the other side (vertical direction (MD)) perpendicular to the horizontal direction (TD)), resulting in a bag-like sample with an open vertical side ( FIG. 6b ). As shown in FIG. 6b , the widths of the heat-sealed portions S formed by heat sealing were 7 mm (TD) and 10 mm (MD). A 7 mm-wide heat seal bar was used, and a single heat seal was performed in the TD direction to make the width of the heat-sealed portion S 7 mm. In addition, in the MD direction, two heat seals were performed using a 7 mm wide heat seal bar offset to make the width of the heat-sealed portion S 10 mm. In the MD direction, the center (4 mm wide) of the 10 mm wide heat-sealed portion S was heat-sealed twice. The heat-sealing conditions for one side in the horizontal direction (TD direction) were a temperature of 190°C, a surface pressure of 1.0 MPa, and a time of 3 seconds. The heat-sealing conditions for one side in the vertical direction (MD direction) were a temperature of 190°C, a surface pressure of 2.0 MPa, and a time of 3 seconds. Next, the bag-shaped sample was cut so that the width of the heat-sealed portion of one side in the horizontal direction (TD direction) was 3 mm, and the sample was dried in a dry room for 24 hours (Figure 6c). Next, a 20 mm x 20 mm moisture adsorption film is placed through the opening of the bag-shaped sample, and one side of the opening (longitudinal direction (MD direction)) is vacuum-sealed (approximately -100 kPa). The heat-sealed side is then heat-sealed in the same manner as the heat-sealed longitudinal direction (MD direction) side, so that the width of the heat-sealed portion S is 10 mm, to prepare a measurement sample (package 11 as the test subject) (Figure 6e).

[0221] (Measurement of Moisture Permeability Coefficient) The measurement sample is stored in a thermo-hygrostat chamber in a gas-phase environment with a temperature of 35°C to 65°C and a relative humidity of 85% or higher for a storage period of 17 days. A separate measurement sample is also stored in a dry room for reference. Next, the measurement sample is removed from the thermo-hygrostat chamber. A moisture adsorption film is removed from the measurement sample, and the amount of moisture absorbed by the moisture adsorption layer of the moisture adsorption film in the measurement sample is measured in the dry room using a near-infrared spectrometer. The moisture adsorption film is removed from the measurement sample, and its IR absorption spectrum is measured. A known amount of moisture is adsorbed onto the moisture adsorption film before moisture adsorption, and the absorption spectrum of the measurement sample is substituted into a regression equation previously prepared from the absorption spectrum measured with the near-infrared spectrometer to calculate the moisture permeation amount [μg]. The average of five points on the measurement sample is taken as the moisture permeation amount of one measurement sample.

[0222] The present disclosure will be described in detail below with reference to examples, but the present disclosure is not limited to these examples.

[0223] [Example] <Production of Sheathing Material A for Electricity Storage Devices> A biaxially oriented polyethylene terephthalate (PET) film (thickness 12 μm) and an oriented nylon (ONy) film (thickness 15 μm) were prepared as the base material layer. The PET film and the ONy film were bonded using a two-component urethane adhesive (a polyol compound and an aromatic isocyanate compound) and aging treatment was performed to obtain a base material layer (thickness 30 μm) in which the PET film (thickness 12 μm) / adhesive layer (thickness after curing 3 μm) / ONy film (thickness 15 μm) were laminated from the outside in this order. In addition, aluminum foil (JIS H4160:1994 A8021H-O (thickness 40 μm)) was prepared as the barrier layer. Next, the ONy film side surface of the substrate layer and the barrier layer were bonded using a two-component urethane adhesive (a polyol compound and an aromatic isocyanate compound), and an aging treatment was performed to produce a laminate of substrate layer (thickness 30 μm) / adhesive layer (thickness 3 μm after curing) / barrier layer (thickness 40 μm). Both sides of the aluminum foil were subjected to a chemical conversion treatment. The chemical conversion treatment of the aluminum foil was performed using a treatment solution consisting of a phenolic resin, a chromium fluoride compound, and phosphoric acid, with a coating amount of chromium of 10 mg / m. 2 (dry mass) was applied to both sides of an aluminum foil by roll coating, and baked.

[0224] Next, on the barrier layer of the laminate obtained above, maleic anhydride-modified polypropylene as an adhesive layer (thickness 40 μm) and random polypropylene as a heat-sealable resin layer (thickness 40 μm) were co-extruded to obtain an exterior packaging material for an electricity storage device (total thickness 153 μm) in which the base material layer (thickness 30 μm) / adhesive layer (3 μm) / barrier layer (40 μm) / adhesive layer (40 μm) / heat-sealable resin layer (40 μm) were laminated in this order.

[0225] <Production of Power Storage Device Sheathing Material B> A polyethylene terephthalate film (thickness 25 μm) was prepared as the substrate layer, with the bonding surface subjected to corona treatment. Furthermore, an aluminum alloy foil (JIS H4160:1994 A8021H-O, thickness 40 μm) was prepared as the barrier layer. Furthermore, each of the above films was used as the heat-sealable resin layer. Next, the substrate layer and the barrier layer were bonded together by a dry lamination method using a two-component curing urethane adhesive (polyester polyol and alicyclic isocyanate compound), to produce a laminate in which the substrate layer / adhesive layer / barrier layer were laminated in this order.

[0226] Next, a two-component curing urethane adhesive (polyester polyol and alicyclic isocyanate compound) was used to adhere the barrier layer side of the obtained laminate to a film by dry lamination, and an adhesive layer (4 μm) / thermal-sealable resin layer was laminated on the barrier layer. Next, the obtained laminate was aged and heated to obtain an exterior packaging material B for an electricity storage device, which consisted of a laminate in which a base layer / adhesive layer / barrier layer / adhesive layer / thermal-sealable resin layer were laminated in this order. The thermal-sealable resin layer (thickness 40 μm) was formed from a homopolybutylene terephthalate film (unstretched homopolybutylene terephthalate (PBT: (constituent units are terephthalic acid and 1,4-butanediol)).

[0227] <Preparation of Moisture Adsorption Film> (Example 1) A CaO-containing polyethylene sheet (thickness 50 μm, manufactured by Sasaki Chemical Co., Ltd. under the trade name S-KID) was prepared as the moisture adsorption layer of the moisture adsorption film. In addition, a foam sheet (thickness 1 mm, basis weight 24.5 g / cm) was prepared as the porous layer of the moisture adsorption film. 2 A moisture adsorption film was prepared by stacking a moisture adsorption layer and a porous layer.

[0228] Example 2 A moisture adsorption film was prepared in the same manner as in Example 1, except that the moisture adsorption layer and the porous layer were stacked and thermally laminated to form a moisture adsorption film.

[0229] Example 3 A moisture adsorption film was prepared in the same manner as in Example 1, except that a porous layer, a moisture adsorption layer, and a porous layer were stacked in this order and thermally laminated to form a moisture adsorption film.

[0230] Example 4 A moisture adsorption film was prepared in the same manner as in Example 1, except that the moisture adsorption layer and the porous layer were bonded together with an adhesive. DICSEAL manufactured by DIC was used as the adhesive.

[0231] Example 5 A resin composition consisting of 50% by weight of linear low-density polyethylene (MI-2, d-0,920) made from ethylene-butene-1 copolymer, 20% by weight of CaO-containing masterbatch (Sasaki Chemical S-KID), 28% by weight of calcium carbonate (average particle size 2.0 μm), and 2% by weight of calcium oxide was used in a T-die film forming machine to obtain an 80 μm porous adsorbent film. This was stretched twice in the machine direction at 50°C to obtain a 40 μm porous film, which was used as a moisture adsorbent film.

[0232] Example 6 In Example 6, the same moisture adsorption film as in Example 1 was used, and the <Evaluation of moisture permeability> described below was performed using packaging material B for an electricity storage device.

[0233] Comparative Example 1 Only the moisture adsorption layer used in Example 1 was used as a moisture adsorption film.

[0234] <Evaluation of Moisture Permeability> (Preparation of Measurement Samples) The test specimens for the electrical storage device outer casing material A (Examples 1 to 5 and Comparative Example 1) and the electrical storage device outer casing material B (Example 6) were each cut into a square sample measuring 120 mm in length (MD) x 120 mm in width (TD), and the sample was folded back in the MD direction at the center position P so that the heat-sealable resin layers faced each other (FIG. 6a). Next, the heat-sealable resin layers were heat-sealed on one side facing the center position P (horizontal direction (TD)) and one side perpendicular thereto (vertical direction (MD)), respectively, to form a bag-like sample with an open side in the vertical direction (MD) (FIG. 6b). As shown in FIG. 6b, the width of the heat-sealed portion S formed by heat sealing was 7 mm (TD) and 10 mm (MD), respectively. At this time, a 7 mm wide heat seal bar was used, and one heat seal was performed in the TD direction, so that the width of the heat-sealed portion S was 7 mm. In addition, in the MD direction, a 7 mm wide heat seal bar was shifted and two heat seals were performed, so that the width of the heat-sealed portion S was 10 mm. In the MD direction, the center (4 mm wide) of the 10 mm wide heat-sealed portion S was heat-sealed twice. For the exterior material A for electric storage devices, the heat sealing conditions for one side in the horizontal direction (TD direction) were a temperature of 190 ° C, a surface pressure of 1.0 MPa, and a time of 3 seconds. For the exterior material B for electric storage devices, the heat sealing conditions for one side in the horizontal direction (TD direction) were a temperature of 190 ° C, a surface pressure of 1.0 MPa, and a time of 3 seconds. The conditions for one heat-sealing operation along one side in the machine direction (MD) were a temperature of 240°C, a surface pressure of 2.0 MPa, and a duration of 3 seconds. Next, the bag-shaped sample was cut so that the width of the heat-sealed portion along one side in the transverse direction (TD) was 3 mm, and the sample was dried in a dry room for 24 hours (Fig. 6c).Next, a 20 mm x 20 mm moisture adsorption film was placed through the opening of the bag-shaped sample, and one side of the opening (longitudinal direction (MD direction)) was vacuum-sealed (Fuji Impulse FCB-200, approximately -100 kPa). The vacuum-sealed area was further heat-sealed in the same manner as the heat-sealed longitudinal direction (MD direction) side so that the width of the heat-sealed portion S was 10 mm, thereby preparing a measurement sample (packaged body 11 as the test subject) (Figure 6e).

[0235] (Measurement of Moisture Permeation Amount) Measurement samples were stored in a thermo-hygrostat chamber under the respective measurement environments (moisture-containing environments) and measurement times (storage times) listed in Table 1. Separately, measurement samples were stored in a dry room for reference. Next, the measurement samples were removed from the thermo-hygrostat chamber. A moisture adsorption film was removed from the measurement sample, and the amount of moisture absorbed by the moisture adsorption layer of the moisture adsorption film in the measurement sample was measured in the dry room using a near-infrared spectrometer. A VIAVI Micro-NIR (900-1700 nm) was used as the measurement device. Specifically, the moisture adsorption film was removed from the measurement sample, and its absorption spectrum was measured. A known amount of moisture was adsorbed onto the moisture adsorption film before moisture adsorption, and the absorption spectrum of the measurement sample was substituted into a regression equation previously prepared from the absorption spectrum measured with the near-infrared spectrometer to calculate the moisture permeation amount [μg]. The average of five points on the measurement sample was taken as the moisture permeation amount of one measurement sample. The average value and variation of the moisture permeation amount were calculated based on the moisture permeation amounts of the three measurement samples. The variation was measured with N=3 and calculated using the formula: Variation % = {(maximum value - average value) + (average value - minimum value)} / average value x 100. The results are shown in Table 1. The moisture permeation amount [μg] shown in Table 1 is the amount of moisture absorbed by the moisture adsorption film. The moisture permeation coefficient [g mm / m] from the heat-sealed portion between the heat-sealable resin layers of the test package was also calculated. 2 / day] is calculated from the average value of the moisture permeation amount [μg] in Table 1 using the following formula. The two heat-sealable resin layers (80 μm each) of the electrical storage device packaging material A were crushed by heat sealing to a thickness remaining rate of about 70%, and the total thickness of the two heat-sealable resin layers after heat sealing was 160 μm × 0.7 = 112 μm. On the other hand, the two heat-sealable resin layers (40 μm each) of the electrical storage device packaging material B were crushed by heat sealing to a thickness remaining rate of about 80%, and the total thickness of the two heat-sealable resin layers after heat sealing was 80 μm × 0.8 = 64 μm. In Examples 1 to 5, the average value was 6.17 g mm / m 2 / day, and in Examples 1 to 6, the average value was 6.49 g mm / m 2 / day, and in Comparative Example 1, it was 2.62 g mm / m 2 / day. Moisture permeability coefficient [g mm / m 2 / day] = Moisture permeation amount (g) x permeation distance (mm) / permeation area (m 2 ) / Number of storage days (days)

[0236]

[0237] In Table 1, a storage environment of 65°C and 90% RH means a storage environment in which the relative humidity is adjusted to 90% at an environmental temperature of 65°C.

[0238] The method for evaluating the moisture permeability of an electrical storage device packaging material of Examples 1-6 includes the steps of: preparing an electrical storage device packaging material composed of a laminate including, in order from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer; sealing a moisture adsorption film in a package obtained by heat-sealing the heat-sealable resin layers to each other at the periphery of the electrical storage device packaging material; placing the package with the moisture adsorption film sealed in a moisture-containing environment; and measuring the amount of moisture absorbed by the moisture adsorption film in the package, wherein the moisture adsorption film includes a porous layer. The method for evaluating the moisture permeability of an electrical storage device packaging material of Example 1 is a novel method for evaluating the moisture permeability of an electrical storage device packaging material, and it can be seen that the variance in the measured values ​​of the moisture increase amount of the solid moisture absorbent is small, and the evaluation accuracy of the moisture permeability of the electrical storage device packaging material is high. The variation is determined to be small when it is 20% or less, and the variation is preferably 15% or less, and more preferably 10% or less.

[0239] As described above, the present disclosure provides the following aspects of the invention. Item 1. A method for evaluating the moisture permeability of an electrical storage device exterior material, comprising: a step of preparing an electrical storage device exterior material composed of a laminate including, in order from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer; a sealing step of sealing a moisture adsorption film in a package obtained by heat-sealing the heat-sealable resin layers together at the periphery of the electrical storage device exterior material; a step of placing the package with the moisture adsorption film sealed in an environment containing moisture; and a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the package, wherein the moisture adsorption film includes a porous layer. Item 2. The method for evaluating the moisture permeability of an electrical storage device exterior material according to Item 1, wherein the electrical storage device exterior material is an exterior material for an all-solid-state battery or an exterior material for a semi-solid battery. Item 3. Item 4. The method for evaluating the moisture permeability of a packaging material for an electricity storage device according to any one of Items 1 to 3, wherein the moisture-containing environment is a gas-phase environment having a temperature of 20°C or higher and 200°C or lower and a relative humidity of 0.05% or higher.Item 5. A quality control method for an electrical storage device packaging material, wherein the quality control method targets an electrical storage device packaging material constituted by a laminate including, in order from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer, and comprises: an extraction step of extracting a test electrical storage device packaging material from the electrical storage device packaging material; a sealing step of sealing a moisture adsorption film in a test package obtained by heat-sealing the heat-sealable resin layers together at the periphery of the test electrical storage device packaging material; a step of placing the test package with the moisture adsorption film sealed in an environment containing moisture; a moisture amount measurement step of measuring the amount of moisture absorbed by the moisture adsorption film in the test package; and a determination step of determining whether the electrical storage device packaging material is non-defective based on the amount of moisture absorbed by the moisture adsorption film, wherein the moisture adsorption film includes a porous layer. The moisture-containing environment is a gaseous environment with a temperature of 35°C or higher and 65°C or lower and a relative humidity of 85% or higher, and in the determination step, the moisture permeability coefficient from the heat-sealed portion between the heat-sealable resin layers of the test package is calculated based on the amount of moisture absorbed by the moisture adsorption film, and the moisture permeability coefficient is 10 g mm / m. 2 or the moisture-containing environment is a gaseous environment having a temperature higher than 65°C and not higher than 90°C and a relative humidity of 85% or higher, and in the determination step, a moisture permeability coefficient from the heat-sealed portion between the heat-sealable resin layers of the package to be tested is calculated based on the amount of moisture absorbed by the moisture adsorption film, and the moisture permeability coefficient is determined to be 20 g mm / m or less. 2Item 7. The quality control method for an electrical storage device packaging material according to Item 5, wherein the electrical storage device packaging material is a packaging material for an all-solid-state battery or a packaging material for a semi-solid battery. Item 8. The quality control method for an electrical storage device packaging material according to any one of Items 5 to 7, wherein in the moisture amount measuring step, the moisture adsorption film is removed from the package to be tested, and the amount of moisture absorbed by the moisture adsorption film in the package to be tested is measured. Item 9. Item 10. A method for manufacturing an electrical storage device packaging material, comprising the steps of: obtaining a laminate by laminating, from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer in this order; an extraction step of extracting a test electrical storage device packaging material from the laminate; a sealing step of sealing a moisture adsorption film in a test package obtained by heat-sealing the heat-sealable resin layers together at the periphery of the test electrical storage device packaging material; placing the test package with the sealed moisture adsorption film in an environment containing moisture; a moisture amount measurement step of measuring the amount of moisture absorbed by the moisture adsorption film in the test package; and a determination step of determining whether the electrical storage device packaging material is non-defective based on the amount of moisture absorbed by the moisture adsorption film, wherein the moisture adsorption film includes a porous layer. The moisture-containing environment is a gaseous environment having a temperature of 35°C or higher and 65°C or lower and a relative humidity of 85% or higher, and in the determination step, a moisture permeability coefficient from the heat-sealed portion between the heat-sealable resin layers of the test package is calculated based on the amount of moisture absorbed by the moisture adsorption film, and the moisture permeability coefficient is 10 g mm / m 2 or the moisture-containing environment is a gaseous environment having a temperature higher than 65°C and not higher than 90°C and a relative humidity of 85% or higher, and in the determination step, a moisture permeability coefficient from the heat-sealed portion between the heat-sealable resin layers of the package to be tested is calculated based on the amount of moisture absorbed by the moisture adsorption film, and the moisture permeability coefficient is determined to be 20 g mm / m or less. 2Item 11. The method for producing an electrical storage device packaging material according to Item 9, wherein the electrical storage device packaging material is an electrical storage device packaging material for an all-solid-state battery or an electrical storage device packaging material for a semi-solid battery. Item 12. The method for producing an electrical storage device packaging material according to any one of Items 9 to 11, wherein in the moisture amount measuring step, the moisture adsorption film is removed from the package to be tested, and the amount of moisture absorbed by the moisture adsorption film in the package to be tested is measured. Item 13. 1. A method for manufacturing an electricity storage device, in which an electricity storage device element is sealed with a packaging body formed by heat-sealing a heat-sealable resin layer around the periphery of an exterior packaging material for an electricity storage device, the packaging material being composed of a laminate having, in this order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer, wherein the exterior packaging material for an electricity storage device is constituted by a laminate having, in this order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer, and the method for manufacturing the electricity storage device includes: an extraction step of extracting a subject electricity storage device packaging material from the electricity storage device packaging material; a sealing step of sealing a moisture adsorption film in a subject packaging material obtained by heat-sealing the heat-sealable resin layers around the periphery of the subject electricity storage device packaging material; a step of placing the subject packaging material with the moisture adsorption film sealed in it in a moisture-containing environment; a moisture amount measurement step of measuring the amount of moisture absorbed by the moisture adsorption film in the subject packaging material; and a determination step of determining whether the subject electricity storage device packaging material is a non-defective product based on the amount of moisture absorbed by the moisture adsorption film. and a step of manufacturing an electricity storage device by accommodating an electricity storage device element in a packaging body formed from the electricity storage device exterior material, wherein the moisture adsorption film includes a porous layer, and when the electricity storage device exterior material is determined to be a non-defective product as a result of the determination step, the method for manufacturing an electricity storage device includes accommodating an electricity storage device element in a packaging body formed from the electricity storage device exterior material to manufacture the electricity storage device.Item 14. The moisture-containing environment is a gaseous environment having a temperature of 35°C or higher and 65°C or lower and a relative humidity of 85% or higher, and in the determination step, a moisture permeability coefficient from the heat-sealed portion between the heat-sealable resin layers of the test package is calculated based on the amount of moisture absorbed by the moisture adsorption film, and the moisture permeability coefficient is 10 g mm / m. 2 or the moisture-containing environment is a gaseous environment having a temperature higher than 65°C and not higher than 90°C and a relative humidity of 85% or higher, and in the determination step, a moisture permeability coefficient from the heat-sealed portion between the heat-sealable resin layers of the package to be tested is calculated based on the amount of moisture absorbed by the moisture adsorption film, and the moisture permeability coefficient is determined to be 20 g mm / m or less. 2Item 15. The method for manufacturing an electricity storage device according to Item 13, wherein the electricity storage device packaging material is a packaging material for an all-solid-state battery or a packaging material for a semi-solid battery. Item 16. The method for manufacturing an electricity storage device according to any one of Items 13 to 15, wherein in the moisture amount measuring step, the moisture adsorption film is removed from the package to be tested, and the amount of moisture absorbed by the moisture adsorption film in the package to be tested is measured. Item 17. Item 17. A moisture adsorption film used in a method for evaluating the moisture permeability of an electrical storage device exterior material, the moisture adsorption film including a porous layer, the method for evaluating the moisture permeability of an electrical storage device exterior material comprising: a step of preparing the electrical storage device exterior material composed of a laminate including, in order from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer; a sealing step of sealing the moisture adsorption film in a package obtained by heat-sealing the heat-sealable resin layers together at the periphery of the electrical storage device exterior material; a step of placing the package with the sealed moisture adsorption film in a moisture-containing environment; and a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the package. Item 18. A moisture adsorption film used in a method for evaluating the moisture permeability of an electrical storage device exterior material, the moisture adsorption film including a porous layer, the method comprising: a step of preparing the electrical storage device exterior material composed of a laminate including, in order from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer; 2an electrical storage device packaging material, the electrical storage device packaging material having a moisture permeability of 10 ...

[0240] REFERENCE SIGNS LIST 1 Base material layer 2 Adhesive layer 3 Barrier layer 4 Heat-sealable resin layer 5 Adhesive layer 6 Surface coating layer 10, 50 Electricity storage device packaging material 11, 40 Packaging body A Moisture adsorption film P Central position S Heat-sealed portion 10a Peripheral portion of electricity storage device packaging material 12 Electricity storage device 13 Electricity storage device element 14 Adhesive film 15 Metal terminal 20 Electrode body 30 Moisture adsorption film 31 Porous layer 32 Moisture absorption layer 33 Adhesive layer 60 Lid 70 First sealing portion 80 Second sealing portion

Claims

1. A method for evaluating the moisture permeability of an exterior material for an electricity storage device, comprising the steps of: preparing an exterior material for an electricity storage device composed of a laminate including, in order from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer; a sealing step of sealing a moisture adsorption film in a package obtained by heat-sealing the heat-sealable resin layers together at the periphery of the exterior material for an electricity storage device; placing the package with the moisture adsorption film sealed in it in an environment containing moisture; and a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the package, wherein the moisture adsorption film includes a porous layer.

2. The method for evaluating the moisture permeability of an exterior material for an electricity storage device according to claim 1, wherein the exterior material for an electricity storage device is an exterior material for an all-solid-state battery or an exterior material for a semi-solid battery.

3. A method for evaluating the moisture permeability of an exterior material for an electrical storage device as described in claim 1 or 2, wherein in the moisture amount measuring step, the moisture adsorption film is removed from the packaging body, and the amount of moisture absorbed by the moisture adsorption film in the packaging body is measured.

4. A method for evaluating the moisture permeability of an exterior material for a storage battery device as described in claim 1 or 2, wherein the moisture-containing environment is a gas phase environment having a temperature of 20°C or higher and 200°C or lower and a relative humidity of 0.05% or higher.

5. A quality control method for an electrical storage device exterior material, the quality control method targets an electrical storage device exterior material constituted by a laminate including, in order from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer, and the quality control method comprises the steps of: extracting an electrical storage device exterior material to be tested from the electrical storage device exterior material; sealing a moisture adsorption film in a test package obtained by heat-sealing the heat-sealable resin layers together at the periphery of the electrical storage device exterior material to be tested; placing the test package in which the moisture adsorption film is sealed in an environment containing moisture; a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the test package; and judging whether the electrical storage device exterior material is a non-defective product based on the amount of moisture absorbed by the moisture adsorption film, wherein the moisture adsorption film includes a porous layer.

6. The moisture-containing environment is a gas-phase environment having a temperature of 35°C to 65°C and a relative humidity of 85% or more, and in the judgment step, the moisture permeability coefficient from the heat-sealed portion between the heat-sealable resin layers of the test package is calculated based on the amount of moisture absorbed by the moisture adsorption film, and the moisture permeability coefficient is 10 g mm / m 2 or if the moisture-containing environment is a gas phase environment having a temperature of more than 65° C. and not more than 90° C. and a relative humidity of 85% or more, and in the determination step, a moisture permeability coefficient from a heat-sealed portion between the heat-sealable resin layers of the test package is calculated based on the amount of moisture absorbed by the moisture adsorption film, and the moisture permeability coefficient is determined to be 20 g mm / m or less. 2 The quality control method for an electrical storage device packaging material according to claim 5 , wherein the electrical storage device packaging material is determined to be non-defective when the electrical storage device packaging material has a quality of 0.1 to 0.5% by weight per unit area (L / day) or less.

7. The quality control method for an exterior material for an electricity storage device according to claim 5 or 6, wherein the exterior material for an electricity storage device is an exterior material for an all-solid-state battery or an exterior material for a semi-solid battery.

8. A quality control method for an exterior material for an electrical storage device as described in claim 5 or 6, wherein in the moisture amount measuring step, the moisture adsorption film is removed from the test package and the amount of moisture absorbed by the moisture adsorption film in the test package is measured.

9. A manufacturing method for an exterior material for an electricity storage device, comprising the steps of: obtaining a laminate by laminating, from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer in this order; an extraction step of extracting an exterior material for an electricity storage device to be tested from the exterior material for an electricity storage device consisting of the laminate; a sealing step of sealing a moisture adsorption film in a package to be tested obtained by heat-sealing the heat-sealable resin layers to each other at the periphery of the exterior material for an electricity storage device to be tested; a step of placing the package to be tested in which the moisture adsorption film is sealed, in an environment containing moisture; a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the package to be tested; and a judgment step of judging whether or not the exterior material for an electricity storage device is non-defective based on the amount of moisture absorbed by the moisture adsorption film, wherein the moisture adsorption film includes a porous layer.

10. The moisture-containing environment is a gas-phase environment having a temperature of 35°C to 65°C and a relative humidity of 85% or more, and in the judgment step, the moisture permeability coefficient from the heat-sealed portion between the heat-sealable resin layers of the test package is calculated based on the amount of moisture absorbed by the moisture adsorption film, and the moisture permeability coefficient is 10 g mm / m 2 or if the moisture-containing environment is a gas phase environment having a temperature of more than 65° C. and not more than 90° C. and a relative humidity of 85% or more, and in the determination step, a moisture permeability coefficient from a heat-sealed portion between the heat-sealable resin layers of the test package is calculated based on the amount of moisture absorbed by the moisture adsorption film, and the moisture permeability coefficient is determined to be 20 g mm / m or less. 2 The method for producing an exterior material for an electricity storage device according to claim 9 , wherein the exterior material for an electricity storage device is determined to be a non-defective product when the residual capacity is less than or equal to 100%.

11. The method for producing an exterior material for an electricity storage device according to claim 9 or 10, wherein the exterior material for an electricity storage device is an exterior material for an all-solid-state battery or an exterior material for a semi-solid battery.

12. A method for manufacturing an exterior material for an electricity storage device as described in claim 9 or 10, wherein in the moisture amount measuring step, the moisture adsorption film is removed from the test package and the amount of moisture absorbed by the moisture adsorption film in the test package is measured.

13. A method for manufacturing an electricity storage device, in which an electricity storage device element is sealed with a packaging body formed by heat-sealing a heat-sealable resin layer at the periphery of an exterior material for an electricity storage device composed of a laminate having, in this order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer, the method for manufacturing the electricity storage device comprising: an extraction step of extracting a test electricity storage device exterior material from the exterior material for an electricity storage device; a sealing step of sealing a moisture adsorption film in a test packaging body obtained by heat-sealing the heat-sealable resin layers at the periphery of the exterior material for an electricity storage device to be tested; a step of placing the test packaging body with the moisture adsorption film sealed therein in an environment containing moisture; a moisture amount measurement step of measuring the amount of moisture absorbed by the moisture adsorption film in the test packaging body; and a determination step of determining whether the test electricity storage device exterior material is a non-defective product based on the amount of moisture absorbed by the moisture adsorption film. and manufacturing an electricity storage device by accommodating an electricity storage device element in a packaging body formed from the electricity storage device exterior material, wherein the moisture adsorption film includes a porous layer, and when the electricity storage device exterior material is determined to be a non-defective product as a result of the determination step, the method for manufacturing an electricity storage device includes accommodating an electricity storage device element in a packaging body formed from the electricity storage device exterior material to manufacture an electricity storage device.

14. The moisture-containing environment is a gas-phase environment having a temperature of 35°C to 65°C and a relative humidity of 85% or more, and in the judgment step, the moisture permeability coefficient from the heat-sealed portion between the heat-sealable resin layers of the test package is calculated based on the amount of moisture absorbed by the moisture adsorption film, and the moisture permeability coefficient is 10 g mm / m 2 or if the moisture-containing environment is a gas phase environment having a temperature of more than 65° C. and not more than 90° C. and a relative humidity of 85% or more, and in the determination step, a moisture permeability coefficient from a heat-sealed portion between the heat-sealable resin layers of the test package is calculated based on the amount of moisture absorbed by the moisture adsorption film, and the moisture permeability coefficient is determined to be 20 g mm / m or less. 2 The method for producing an electricity storage device according to claim 13 , wherein the electrical storage device exterior material is determined to be non-defective when the electrical storage device exterior material has a residual capacity of 1000 saturation voltage of 100 / day or less.

15. The method for producing an electricity storage device according to claim 13 or 14, wherein the exterior material for an electricity storage device is an exterior material for an all-solid-state battery or an exterior material for a semi-solid battery.

16. A method for manufacturing an electricity storage device as described in claim 13 or 14, wherein in the moisture amount measuring step, the moisture adsorption film is removed from the test package and the amount of moisture absorbed by the moisture adsorption film in the test package is measured.

17. A moisture adsorption film used in a method for evaluating the moisture permeability of an exterior material for an electricity storage device, the moisture adsorption film including a porous layer, the method for evaluating the moisture permeability of an exterior material for an electricity storage device comprising the steps of: preparing the exterior material for an electricity storage device composed of a laminate including, in order from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer; a sealing step of sealing the moisture adsorption film in a packaging body obtained by heat-sealing the heat-sealable resin layers together at the peripheral portion of the exterior material for an electricity storage device; placing the packaging body with the moisture adsorption film sealed in it in a moisture-containing environment; and a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the packaging body.

18. An exterior material for an electrical storage device, which is composed of a laminate including, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer, and which has a moisture permeability coefficient of 10 g mm / m or less calculated by a measurement method including the following steps: 2 / day or less. The method comprises the steps of: extracting an electrical storage device exterior material to be tested from the electrical storage device exterior material; sealing a moisture adsorption film including a porous layer in a test package obtained by heat-sealing the heat-sealable resin layers at the peripheral portion of the electrical storage device exterior material to be tested; placing the test package with the moisture adsorption film sealed therein in an environment containing moisture; measuring a moisture amount of the test package containing moisture; and calculating a moisture permeability coefficient from the heat-sealed portion between the heat-sealed resin layers of the test package based on the moisture amount of the moisture adsorption film, wherein the moisture-containing environment is a gas phase environment having a temperature of 35° C. or higher and 65° C. or lower and a relative humidity of 85% or higher.

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