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

Abstract

To provide a novel method for evaluating moisture permeability of an outer package material for power storage devices.SOLUTION: There is provided a method for evaluating moisture permeability of an outer package material 10 for power storage devices. The method includes: a step of 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 of sealing a moisture adsorption film 30 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 of placing the package, in which the moisture adsorption film is sealed, in an environment that includes moisture; and a moisture measurement step of measuring the amount of moisture absorbed by the moisture adsorption film in the package. The moisture adsorption film includes a porous layer.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[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. [Background technology]

[0002] Various types of electricity storage devices have been developed, and in all of them, exterior materials are essential components for sealing the 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 sequentially laminated 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. [Prior art documents] [Patent documents]

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

[0007] In an electricity storage device using such a film-like electricity storage device packaging material, the heat-sealed portion between the heat-sealable resin layers at the periphery of the electricity storage device packaging material 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-sealable resin layers of the electricity storage device packaging material, perpendicular to the thickness direction of the heat-sealable resin layers). If moisture penetrates into 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. [Means for solving the problem]

[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 based on these findings and further investigations. That is, the present disclosure provides the inventions of the following aspects. A method for evaluating moisture permeability of an exterior material for an electricity storage device, comprising: preparing an exterior packaging material for an electricity storage device that is 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 peripheral edge of the exterior packaging material for an electricity storage device; placing the package with the moisture absorbing film sealed in a moist environment; a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the package; It is equipped with The method for evaluating the moisture permeability of an exterior material for an electricity storage device, wherein the moisture adsorption film includes a porous layer. [Effects of the Invention]

[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. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. [Figure 2] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. [Figure 3] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. [Figure 4] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. [Figure 5] FIG. 2 is a schematic diagram illustrating a method for housing an electricity storage device element in a package formed from the exterior packaging material for an electricity storage device of the present disclosure. [Figure 6] FIG. 2 is a schematic diagram illustrating a method for preparing a measurement sample (packaged body as a test subject) for evaluating moisture permeability in the Examples. [Figure 7] FIG. 1 is a perspective view of an example of an electricity storage device. [Figure 8]1 is a schematic diagram showing an example of a cross-sectional structure of a moisture adsorption film according to the present disclosure. [Figure 9] 1 is a schematic diagram showing an example of a cross-sectional structure of a moisture adsorption film according to the present disclosure. [Figure 10] 1 is a schematic diagram showing an example of a cross-sectional structure of a moisture adsorption film according to the present disclosure. [Figure 11] 1 is a schematic diagram showing an example of a cross-sectional structure of a moisture adsorption film according to the present disclosure. [Figure 12] 1 is a schematic diagram showing an example of a cross-sectional structure of a moisture adsorption film according to the present disclosure. [Figure 13] 1 is a schematic diagram showing an example of a cross-sectional structure of a moisture adsorption film according to the present disclosure. [Figure 14] 1 is a schematic diagram illustrating an example of a cross-sectional structure of an electricity storage device according to the present disclosure. [Figure 15] 1 is a schematic diagram illustrating an example of a cross-sectional structure of an electricity storage device according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[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 sealed moisture adsorption film in a moist 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 moisture permeability evaluation method according to the present disclosure is a novel evaluation 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 would swell 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 more 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 be combined to form respective numerical ranges. 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 streaks known as 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 identified 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 identified due to rolling marks on a metal foil such as an aluminum alloy foil or a stainless steel foil, it can be identified by the following method. One method for confirming 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 cross section in the longitudinal direction of the heat-sealable resin layer and each cross section at an angle of 10 degrees from the direction parallel to the longitudinal cross section up to the direction perpendicular to the longitudinal cross section (a total of 10 cross sections) are observed using an electron microscope to confirm the sea-island structure. 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 as 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 moisture permeability of packaging materials for energy storage devices The method for evaluating the moisture permeability of an electrical storage device packaging material according to the present disclosure can be used in the manufacturing process of an electrical storage device packaging material, the manufacturing process of an electrical storage device, etc. In the method for evaluating the moisture permeability of an electrical storage device packaging material according to the present disclosure, the electrical storage device packaging 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 electrical storage device packaging 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 carried out to seal the moisture adsorption film 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 where 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.)), the moisture absorption amount (theoretical value) of the adsorbent contained in the moisture adsorption film, etc.

[0027] A moisture adsorption film is a film that has 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 that has 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. In addition, 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 configuration in which a porous layer and a moisture adsorption layer are laminated together, a three-layer configuration in which a porous layer, a moisture adsorption layer, and a porous layer are laminated together in this order, a three-layer configuration in which a porous layer, an adhesive layer, and a moisture adsorption layer are laminated together in this order, a five-layer configuration 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 configuration 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 configuration or a multi-layer configuration.

[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 FIGS. 8 to 13 (each of which is a schematic diagram showing an example of the cross-sectional structure of a moisture adsorption film). As shown in FIG. 8, a moisture adsorption film 30 may be composed of only a porous layer 31. Alternatively, as shown in FIGS. 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. FIG. 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. FIG. 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. FIG. 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. FIG. 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. Figure 13 shows the 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 adsorbing 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 for an electricity storage device, thereby improving 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 packaging material 10 is used to house the electricity storage device element 13, the packaging 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 of the packaging material 10 (the peripheral edge portion 10a 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. Pouch types include three-sided seal, four-sided seal, and pillow-type, 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 a moisture permeation path is ensured, but it is preferable that it be moisture permeable. In addition, it is also preferable that the porous layer include communicating pores 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. The microcapsule-type foaming agent preferably has 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 thermoplastic resins 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 thermal adhesiveness.

[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 is sufficient to ensure a moisture permeation path in the vacuum-sealed package. From the viewpoint of optimally exerting 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. The thickness is also 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 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 Approximately 20~50g / cm2 Degree, 20~40g / cm 2 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. The moisture adsorption film of the present disclosure may also 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 moisture adsorbents 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 are capable of adsorption 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 (such as 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, and 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 even trace amounts of moisture to be measured in a short time. Zeolite (e.g., molecular sieve) also has the advantage that the amount of moisture absorbed 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 even trace amounts of moisture to be measured in a short time.

[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 methods such as measuring the weight of moisture absorbed by the 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 only, 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 thermal adhesiveness.

[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, and 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 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] (Preparation example of the package 11 to be tested) The test specimen for the energy storage device packaging material was a square sample measuring 120 mm in length (MD) × 120 mm in width (TD). It was folded back in the MD direction at the center position P so that the heat-sealable resin layers faced each other (Figure 6a). Next, the side facing the center position P (the horizontal direction (TD)) and the side perpendicular to it (the vertical direction (MD)) were heat-sealed to heat-seal the heat-sealable resin layers, resulting in a bag-like sample with an open vertical side (Figure 6b). As shown in Figure 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 achieve a 7 mm width for the heat-sealed portion S. Furthermore, in the MD direction, two heat seals are performed with a 7 mm wide heat seal bar offset, 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 an electricity storage device, 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 an electricity storage device, 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 an electricity storage device, 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 an electricity storage device, 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 is cut so that the width of the heat-sealed part on one side in the horizontal direction (TD direction) is 3 mm, and then dried in a dry room for 24 hours (Fig. 6c). Next, a 20 mm x 20 mm moisture adsorption film A 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 vacuum-sealed part is further heat-sealed in the same manner as the heat-sealed longitudinal direction (MD direction) side so that the width of the heat-sealed part S is 10 mm, and a measurement sample (package 11 as the test subject) is prepared (Fig. 6e).

[0066] Next, the package with the sealed moisture adsorption film is placed in a moist environment. In this step, moisture is absorbed into the moisture adsorption film in the package. There are no particular limitations on the moist environment (measurement environment), but a gaseous environment with a temperature of 20 to 200°C and a relative humidity of 0.05% or more is preferred, and a gaseous 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] In addition, the time (measurement time) for which the packaged test subject is placed in a moist environment (measurement environment) can also be adjusted appropriately, 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 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 5g·mm / m 2 / day or less, preferably 2g·mm / m 2 / day or less, more preferably 1g·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 lower 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 18g·mm / m 2 / day or less, preferably 16g·mm / m 2 / day or less, more preferably 15g·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 packaging materials for energy storage devices The quality control method of the present disclosure is a quality control method for an electrical storage device packaging material used in the manufacturing process of an electrical storage device packaging material or in the manufacturing process of an electrical storage device. In the quality control method of the present disclosure, the electrical storage device packaging material that is the subject of quality control is composed of a laminate that includes, from the outside, at least a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4. The laminate structure of the electrical storage device packaging material and details of each layer will be described later.

[0072] The quality control method for a packaging material for an electricity storage device according to the present disclosure includes the following steps. an extraction step of extracting a test electrical storage device packaging material from the electrical storage device packaging materials; 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 outer packaging material for the test storage device; placing the test subject package with the moisture adsorption film sealed in a moist environment; a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the test package; a determining 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;

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

[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 measurement 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 gaseous 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 5g·mm / m 2 / day or less, preferably 2g·mm / m 2 / day or less, more preferably 1g·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. For example, 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, the moisture permeation coefficient can be evaluated as, for example, 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 2 / day or less, preferably 2g·mm / m 2 / day or less, more preferably 1g·mm / m 2 / day or less. Furthermore, when the moisture permeability coefficient from the heat-sealed portion between the heat-sealable resin layers 4 of the package to be tested 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 gaseous environment with a temperature higher than 65°C and lower 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 18g·mm / m 2 / day or less, preferably 16g·mm / m 2 / day or less, more preferably 15g·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 for exterior materials for power storage devices The method for producing an electrical storage device packaging material according to the present disclosure includes a step of laminating, from the outside in this order, at least a base material layer 1, a barrier layer 3, and a thermally adhesive resin layer 4 to obtain a laminate. The laminate structure and each layer of the electrical storage device packaging material will be described in detail below.

[0080] The method for producing an exterior material for an electricity storage device according to the present disclosure includes the following steps. A step of laminating at least a base layer 1, a barrier layer 3, and a heat-sealable resin layer 4 in this order from the outside to obtain a laminate. An extraction step of extracting a test-target electricity storage device packaging material from the electricity storage device packaging material consisting of a laminate. A sealing process in which a moisture adsorption film is sealed in a test package obtained by heat-sealing the heat-sealable resin layers 4 together at the periphery of the outer packaging material for the test storage device. A step of placing the test package sealed with the moisture-absorbing film in a moist environment A moisture amount measurement step of measuring the amount of moisture absorbed by the moisture adsorption film in the test package. A step of determining whether the packaging material for an electricity storage device 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 of 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 of the present disclosure, and among these steps, except for the 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," the "extraction step," and the "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 process" and "determination process" overlap with the processes explained in the section "2. Quality control method for packaging materials for electricity storage devices," and therefore explanations of these processes will also be omitted.

[0084] In the manufacturing method of the exterior packaging material for an electricity storage device of the present disclosure, the step of laminating at least a base material layer 1, a barrier layer 3, and a 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 by laminating in this order the base layer 1, the adhesive layer 2, and the barrier layer 3. 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 the base layer 1 is then laminated thereon, and the adhesive layer 2 is cured.

[0086] Next, a 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, or 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 material layer 1 opposite to the barrier layer 3. The surface coating layer 6 can be formed, for example, by applying the above-mentioned resin for forming the surface coating layer 6 to the surface of the base material layer 1. The order of the step of laminating the barrier layer 3 on the surface of the base material layer 1 and the step of laminating the surface coating layer 6 on the surface of the base material layer 1 is not particularly limited. For example, after the surface coating layer 6 is formed on the surface of the base material layer 1, the barrier layer 3 may be formed on the surface of the base material layer 1 opposite to the surface coating layer 6.

[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 needed to improve processability. For example, by subjecting the surface of the base layer 1 opposite to the barrier layer 3 to corona treatment, the printability of ink on the surface of the base layer 1 can be improved.

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

[0091] 4. Manufacturing method of electricity storage device The method for manufacturing an electricity storage device according to the present disclosure is 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 the heat-sealable resin layer 4 around the periphery of an exterior packaging material 10 for an electricity storage device, which is composed of a laminate including, in this order from the outside, at least a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4. The method for manufacturing an electricity storage device according to the present disclosure utilizes the evaluation method described above in the section "1. Method for evaluating the moisture permeability of an exterior packaging material for an electricity storage device," and therefore, explanation of overlapping matters will be omitted as appropriate. As described above, the laminate structure and each layer of the exterior packaging material for an electricity storage device will be described in detail below.

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

[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 "extraction step," "determination step," and "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 process" and "determination process" overlap with the processes explained in the section "2. Quality control method for packaging materials for electricity storage devices," and therefore explanations of these processes 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 an exterior material for an electricity storage device to form an electricity storage device.

[0098] For example, an electricity storage device using an electrical 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 electrical storage device packaging material in a state in which metal terminals connected to the positive electrode and the negative electrode protrude outward, so that a flange portion (a region where the heat-sealable resin layers 4 contact each other) can be formed around the periphery of the electricity storage device element, 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 electrical storage device packaging material, the package is formed so that the heat-sealable resin portion of the electrical 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 electrical storage device packaging materials with the heat-sealable resin layers 4 facing each other and heat-sealing the peripheral portions of the overlapped electrical storage device packaging materials. Alternatively, as shown in the example of FIG. 5, a package may be formed by folding one electrical storage device packaging material over itself and overlapping it, and heat-sealing the peripheral portions. 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 heat-sealed to the electrical storage device exterior material wrapped around the electrical storage device element. The lid may be formed, for example, from a resin molded product, a metal molded product, an electrical storage device exterior material, or a combination thereof. In this 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 defined by JIS K6900-1994 [Plastics—Terminology]. When the lid is a metal molded product, the lid also functions as a metal terminal, so the metal terminal can be omitted. The lid may be composed of a resin material and a conductive material. Furthermore, the exterior material for an electricity storage device may have a recess for accommodating an electricity storage device element formed therein by deep drawing or stretch forming.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 the other exterior material for an electricity storage device may also have a recess. Fig. 7 shows an example of an electricity storage device in which the exterior material for an electricity storage device does not have a recess. In the electricity storage device 12 of Fig. 7, the exterior material 50 for an electricity storage device is wrapped around the periphery of the electricity storage device element (which has a rectangular parallelepiped shape in Fig. 7) with the heat-sealable resin layer of the exterior material 50 for an electricity storage device 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 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, condensers, and capacitors. Among these secondary batteries, examples of electricity storage devices include lithium ion batteries and lithium ion polymer batteries.

[0100] Laminated structure of exterior materials for power storage devices As shown in FIG. 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 at least a barrier layer 3 and a heat-sealable resin layer 4 in this order. 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 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 for an electricity storage device 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 electricity storage device packaging material 10 is not particularly limited, but from the viewpoint of cost reduction, improving 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 electricity storage device packaging material to protect the electricity storage device elements, the thickness of the laminate constituting the electricity storage device packaging 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 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, a thickness of about 60 to 155 μm is preferred when making an electricity storage device lighter and thinner, and about 155 to 190 μm is preferred when improving formability.

[0104] In the packaging material 10 for an electricity storage device, 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 packaging material 10 for an electricity storage device is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more. As a specific example, when the packaging material 10 for an electricity storage device 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 packaging material 10 for an electricity storage device is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more. Furthermore, even when the packaging material 10 for an electricity storage device 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 packaging material 10 for an electricity storage device can be, for example, 80% or more, preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.

[0105] [Base material layer 1] In the present disclosure, the substrate layer 1 is a layer provided for the purpose of allowing the packaging material for an electricity storage device to function as a substrate. 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 base layer 1, as long as it functions as a base, i.e., has at least insulating properties. The base layer 1 can be formed using, for example, a resin, which may contain additives described below.

[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 laminating the substrate layer 1 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 biaxially stretched films 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 or a modified version of the copolymer. Furthermore, it may also be 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, "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, preferred resins for forming the base layer 1 include polyester and polyamide.

[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), which contain structural units derived from terephthalic acid and / or isophthalic acid; and aromatic polyamides such as polyamide MXD6 (polymetaxylylene adipamide); alicyclic polyamides such as polyamide PACM6 (polybis(4-aminocyclohexyl)methane adipamide); polyamides copolymerized with a lactam component or an isocyanate component such as 4,4'-diphenylmethane diisocyanate; polyesteramide copolymers and polyetheresteramide copolymers, which are copolymers of copolymerized polyamides with polyesters or polyalkylene ether glycols; and polyamides such as copolymers of these. These polyamides may be used singly 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, preferably includes at least one of a stretched polyester film, a stretched polyamide film, and a stretched polyolefin film, more preferably includes at least one of a stretched polyethylene terephthalate film, a stretched polybutylene terephthalate film, a stretched nylon film, and a stretched polypropylene film, and even more preferably includes at least one of a biaxially oriented polyethylene terephthalate film, a biaxially oriented polybutylene terephthalate film, a biaxially oriented nylon film, and a biaxially oriented polypropylene film.

[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 laminates of two or more resin films in the base layer 1 include laminates of polyester film and nylon film, laminates of two or more nylon films, and laminates of two or more polyester films. Preferably, laminates of stretched nylon film and stretched polyester film, laminates of two or more stretched nylon films, and laminates of two or more stretched polyester films are preferred. For example, when the base layer 1 is a laminate of two resin films, a laminate of polyester resin film and polyester resin film, a laminate of polyamide resin film and polyamide resin film, or a laminate of polyester resin film and polyamide resin film is preferred. A laminate of polyethylene terephthalate film and polyethylene terephthalate film, a laminate of nylon film and nylon film, or a laminate of polyethylene terephthalate film and nylon film is more preferred. Furthermore, when the base layer 1 is a laminate of two or more resin films, it is preferred that the polyester resin film be located as the outermost layer of the base layer 1, because polyester resins are less likely to discolor when an electrolyte solution adheres to their surface. 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, and preferred ranges for 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 the same adhesives as 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 by dry lamination, a polyurethane adhesive is preferably used 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 the same adhesives as 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 includes amide-based lubricants. Specific examples of amide-based lubricants include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides. Specific examples of saturated fatty acid amides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide. Specific examples of unsaturated fatty acid amides include oleic acid amide and erucic acid amide. Specific examples of substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide. Specific examples of methylolamides include methylol stearic acid amide. Specific examples of saturated fatty acid bisamides include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipamide, and N,N'-distearyl sebacic acid amide. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipamide, and N,N'-dioleyl sebacic acid amide. Specific examples of fatty acid ester amides include stearamidoethyl stearate. Specific examples of aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, 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 More than 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 that constitutes the base layer 1, or a lubricant applied to the surface of the base layer 1.

[0121] The thickness of the base layer 1 is not particularly limited as long as it functions as a base, but may be, for example, about 3 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. Preferred thickness ranges for 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. When making the electricity storage device thinner and lighter, about 3 to 35 μm, about 3 to 11 μm, or about 3 to 8 μm is preferred. 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 each resin film constituting each layer is not particularly limited, but may be, for example, at least about 2 μm, preferably at least about 10 μm, or at least about 18 μm. 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 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 measuring device.

[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 of the present disclosure, the adhesive layer 2 is a layer that is provided between the base layer 1 and the barrier layer 3 as needed for the purpose of increasing the adhesion between them.

[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 evaporation type, a hot melt type, a hot pressure type, etc. It may also be a two-component curing adhesive (two-component adhesive), a one-component curing adhesive (one-component adhesive), or a resin that does not involve a curing reaction. The adhesive layer 2 may be a single layer or multiple layers.

[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. Among these adhesive components, polyurethane adhesives are preferred. Furthermore, the adhesive strength of these adhesive component resins can be increased by using an appropriate curing agent in combination. The curing agent is selected appropriately from polyisocyanates, multifunctional epoxy resins, oxazoline group-containing polymers, polyamine resins, acid anhydrides, and the like, depending on the functional groups of the adhesive components.

[0130] Examples of polyurethane adhesives include polyurethane adhesives containing a first part containing a polyol compound and a second part containing an isocyanate compound. Preferred examples include two-component curing polyurethane adhesives, 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 curing the polyurethane compound. Polyol compounds preferably include polyester polyols having hydroxyl groups on the side chains in addition to terminal hydroxyl groups in the repeating units. 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). Other examples include polyfunctional isocyanate-modified products 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 side surface is coated with an electrolyte.

[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, and the like. When the adhesive layer 2 contains a colorant, the exterior material for an electricity storage device can be colored. Known colorants such as pigments and dyes can be used as the colorant. Furthermore, only one type of colorant may be used, or two or more types may be mixed together.

[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 measuring device.

[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, or about 2 μm or more. The thickness of the adhesive layer 2 is, for example, about 10 μm or less, or 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. Furthermore, 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 comprise multiple layers. The barrier layer 3 preferably includes a layer composed of a metal material. Specific examples of metal materials constituting the barrier layer 3 include aluminum alloys, stainless steel, titanium steel, and steel plates. When used as a metal foil, the barrier layer 3 preferably includes at least one of aluminum alloy foil and stainless steel foil.

[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, or 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 solely of recycled material, 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 setting the iron content to 0.1% by mass or more, an electrical storage device packaging material with better formability can be obtained. By setting the iron content to 9.0% by mass or less, an electrical storage device packaging material with better flexibility can be obtained. Examples of soft aluminum alloy foils include aluminum alloy foils having a composition specified in JIS H4160:1994 A8021H-O, JIS H4160:1994 A8079H-O, JIS H4000:2014 A8021P-O, or JIS H4000:2014 A8079P-O. Silicon, magnesium, copper, manganese, etc. may be added as needed. Softening can be achieved by annealing or other methods.

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

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

[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 is, 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 an electricity storage device. Furthermore, while increasing the capacity of an electricity storage device increases the weight of the electricity storage device, increasing the 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 made of 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 formed on the surface of the barrier layer by, for example, a hydrothermal conversion treatment such as boehmite treatment, a chemical conversion treatment, anodizing treatment, a nickel or chromium plating treatment, or a corrosion prevention treatment such as applying a coating agent, to provide the barrier layer with corrosion resistance (e.g., acid resistance, alkali resistance, etc.). Specifically, the corrosion-resistant coating refers to a coating that improves the acid resistance of the barrier layer (acid-resistant coating) or a coating that improves the alkali resistance of the barrier layer (alkali-resistant coating). The corrosion-resistant coating may be formed by one type of treatment 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 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 exterior packaging material for an electricity storage device, prevents dissolution and corrosion of the barrier layer surface due to hydrogen fluoride produced by the 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 between the substrate layer and the barrier layer during molding.

[0149] Various corrosion-resistant coatings formed by chemical conversion treatments are known, including 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 primarily composed of a metal phosphate such as Cr (chromium) phosphate, Ti (titanium) phosphate, Zr (zirconium) phosphate, or Zn (zinc) phosphate, or a mixture of these metal salts, or a treatment solution primarily composed of a nonmetallic phosphate and a mixture of these nonmetallic salts, or a mixture of these with a synthetic resin, using 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. The resin component used here may be a polymer such as a phenolic resin or an acrylic resin, or may be a chromate treatment using an aminated phenol polymer having repeating units represented by the following general formulas (1) to (4): In the aminated phenol polymer, the repeating units represented by the following general formulas (1) to (4) may be contained alone or in any combination of two or more types.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] [ka]

[0151] [ka]

[0152] [ka]

[0153] [ka]

[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 2Examples 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 2 Examples 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 formulas (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 formulas (1) to (4) is preferably about 500 to 1,000,000, 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 the functional group (-CHNR 1 R 2 The aminated phenol polymers can 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 has 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. The liquid dispersion medium for the rare earth element oxide sol can be 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 composed 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 are 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, and 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 of fine particles of metal oxides such as aluminum oxide, titanium oxide, cerium oxide, and tin oxide, or barium sulfate dispersed in phosphoric acid to the surface of a barrier layer and 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 using, 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 applying 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, in terms of chromium, of about 0.5 to 50 mg, preferably about 1.0 to 40 mg, the phosphorus compound in terms of phosphorus, and the aminated phenol polymer in an amount, in terms of phosphorus, of about 1.0 to 200 mg, preferably about 5.0 to 150 mg, per unit area.

[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 or 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 the thickness of the corrosion-resistant coating, for example, by measuring the thickness of the coating with secondary ions consisting of Ce, P, and O (e.g., Ce2PO4 + , CePO4 - At least one of the following ions may be present: Cr, P, and O secondary ions (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 other methods, and then heating the barrier layer to a temperature of approximately 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 other methods. By performing such a degreasing treatment, the chemical conversion treatment of the surface of the barrier layer can be carried out more efficiently. Furthermore, using an acid degreasing agent prepared by dissolving a fluorine-containing compound in an inorganic acid for the degreasing treatment not only degreases the metal foil but also forms a passive metal fluoride. In such cases, only the degreasing treatment may be performed.

[0162] [Thermal adhesive resin layer 4] In the packaging material for an electricity storage device of the present disclosure, the heat-sealable resin layer 4 corresponds to the innermost layer and is a layer (sealant layer) that exhibits the function of sealing the electricity storage device elements by heat-sealing the heat-sealable resin layers to each other when assembling the electricity storage device.

[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 Near and wave number 1780cm -1 A peak derived from maleic anhydride is detected around . When the thermally adhesive resin layer 4 is a layer made of maleic anhydride-modified polyolefin, a peak derived from maleic anhydride is detected when measured by infrared spectroscopy. However, if the degree of acid modification is low, the peak becomes small and may not be detected. In such cases, analysis can be performed by nuclear magnetic resonance spectroscopy.

[0164] The thermally adhesive resin layer 4 preferably contains a resin having 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 that is present in the thermally adhesive resin layer 4 at a content of, 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 of the resin components contained in the thermally adhesive resin layer 4. For example, "the thermally adhesive resin layer 4 contains polypropylene as a main component" refers to a resin component that is present in the thermally adhesive resin layer 4 at a content of, 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 of the resin components contained in the thermally adhesive resin layer 4.

[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 polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. Examples of cyclic monomers constituting the cyclic polyolefin include cyclic alkenes such as norbornene; and cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these, preferred are cyclic alkenes, and more preferred are norbornene.

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

[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 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, if necessary. When the thermally adhesive resin layer 4 contains a lubricant, the formability of the packaging material for an electricity storage device 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, and N,N'-distearyl sebacic acid amide. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipamide, and N,N'-dioleyl sebacic acid amide. Specific examples of fatty acid ester amides include stearamidoethyl stearate. Specific examples of aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, 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 packaging material for an electricity 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 electricity 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. When two or more types of lubricants 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 packaging 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 can heat-seal the heat-sealable resin layers to each other and function to seal the electricity storage device element, but may be, for example, about 100 μm or less, preferably about 85 μm or less, and more preferably about 15 to 85 μm. For example, when the thickness of the adhesive layer 5 described below is 10 μm or more, the thickness of the heat-sealable resin layer 4 is preferably about 85 μm or less, and more preferably about 15 to 45 μm. For example, when the thickness of the adhesive layer 5 described below is less than 10 μm or when the adhesive layer 5 is not provided, the thickness of the heat-sealable resin layer 4 is preferably about 20 μm or more, and more preferably about 35 to 85 μm.

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

[0180] The adhesive layer 5 is formed of a resin capable of bonding 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 adhesives as those exemplified for the adhesive layer 2 can be used.

[0181] Furthermore, from the viewpoint of firmly adhering 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 adhering 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 their anhydrides, acrylic acid, and methacrylic acid. However, from the viewpoint of ease of modification and versatility, maleic anhydride is most preferred. Furthermore, 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" refers to a resin component that is present in the adhesive layer 5 at a content of, 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 of the resin components contained in the adhesive layer 5. For example, when the adhesive layer 5 contains acid-modified polypropylene as a main component, it means that the acid-modified polypropylene content of 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 peak at a wave number of 1760 cm -1 Near and wave number 1780cm -1 A peak derived from maleic anhydride is detected around this point. However, if the degree of acid modification is low, the peak may be small and not be detected. In this case, analysis can be performed using nuclear magnetic resonance spectroscopy.

[0184] Furthermore, from the viewpoint of ensuring durability such as heat resistance and resistance to contents of the packaging material for an electricity storage device, 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 mentioned 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. It is particularly 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 and a compound having an epoxy group. 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 components of a curing agent such as a compound having an isocyanate group, a compound having an oxazoline group, or an epoxy resin remain in the adhesive layer 5, the presence of the unreacted components 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 COC 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 COC 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 improving 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 can 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 can effectively improve the adhesion between the barrier layer 3 and the adhesive layer 5.

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

[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. One type of epoxy resin may be used alone, or two or more types may be used in combination.

[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 can 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 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 adhesive layer 5. This effectively improves the adhesion between barrier layer 3 and adhesive layer 5 in an atmosphere containing components that induce 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 10 for an electricity storage device 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, and 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 have a surface coating layer 6 on the substrate layer 1 (the side of the substrate layer 1 opposite to the barrier layer 3) as needed, for the purpose of improving at least one of design, electrolyte resistance, scratch resistance, formability, etc. The surface coating layer 6 is a layer located on the outermost layer side of the packaging material for an electricity storage device when an electricity storage device is assembled using the packaging material for an electricity storage device.

[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 polyurethane compounds prepared by reacting a polyol compound with an isocyanate compound in advance, and polyurethanes containing an isocyanate compound. Examples of polyurethanes include polyurethane compounds prepared by reacting a polyol compound with an isocyanate compound in advance, and polyurethanes containing a polyol compound. Examples of polyurethanes include polyurethanes prepared by reacting a polyol compound with an isocyanate compound in advance and 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 terminal hydroxyl groups in the repeating units. Examples of the second component 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, and thus the exterior packaging material for an electricity storage device is endowed with excellent resistance to an electrolyte solution.

[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 needed, in at least one of the surface and interior of the surface coating layer 6, depending on the functionality to be imparted to the surface of the surface coating layer 6. Examples of additives include fine particles with an average particle size of approximately 0.5 nm to 5 μm. The average particle size of the additive is the median size measured with a laser diffraction / scattering particle size distribution analyzer.

[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, cost, and the like. 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, and N,N'-distearyl sebacic acid amide. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipamide, and N,N'-dioleyl sebacic acid amide. Specific examples of fatty acid ester amides include stearamidoethyl stearate. Specific examples of aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, 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 More than 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 exterior material for an electricity storage device 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 measuring device.

[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. Exterior materials for energy storage devices The present disclosure can also provide the following packaging material for an electricity storage device. An exterior packaging material for an electricity storage device, which is 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, The moisture permeability coefficient calculated using the measurement method below is 10g·mm / m 2 / day or less exterior material for energy storage devices. an extraction step of extracting a test electrical storage device packaging material from the electrical storage device packaging materials; a sealing step of sealing a moisture adsorption film including a porous layer in a test package obtained by heat-sealing the heat-sealable resin layers together at the periphery of the outer packaging material for the test electricity storage device; placing the test subject package with the moisture adsorption film sealed in a moist environment; a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the test package; a calculation step of calculating a moisture permeability coefficient from the heat-sealed portion between the heat-sealable resin layers of the package to be tested based on the amount of moisture absorbed by the moisture adsorption film; Equipped with 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.

[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-absorbing film) A CaO-containing polyethylene sheet (thickness: 50 μm) was prepared as the moisture adsorption layer of the moisture adsorption film. A foam sheet (thickness: 1 mm, basis weight: 24.5 g / cm) was also prepared as the porous layer of the moisture adsorption film. 2 ) is prepared. 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 the package to be tested) The test specimen for the energy storage device packaging material was a square sample measuring 120 mm in length (MD) × 120 mm in width (TD). It was folded back in the MD direction at the center position P so that the heat-sealable resin layers faced each other (Figure 6a). Next, the side facing the center position P (the horizontal direction (TD)) and the side perpendicular to it (the vertical direction (MD)) were heat-sealed to heat-seal the heat-sealable resin layers, resulting in a bag-like sample with an open vertical side (Figure 6b). As shown in Figure 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 ensure the width of the heat-sealed portion S was 7 mm. In the MD direction, two heat seals were performed using a 7 mm-wide heat seal bar offset from one another, resulting in a 10 mm wide heat-sealed section S. In the MD direction, the center (4 mm wide) of the 10 mm-wide heat-sealed section S was heat-sealed twice. The heat-sealing conditions for one crosswise (TD) side were a temperature of 190°C, a surface pressure of 1.0 MPa, and a duration of 3 seconds. The heat-sealing conditions for one crosswise (MD) side were a temperature of 190°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 section on one crosswise (TD) side 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-absorbing 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).Furthermore, in the same manner as the heat-sealed longitudinal direction (MD direction) side, the heat-sealed portion S is heat-sealed so that the width of the heat-sealed portion S is 10 mm, and a measurement sample (packaged body 11 as the test subject) is prepared (Figure 6e).

[0221] (Measurement of moisture permeability coefficient) The measurement sample is stored in a constant temperature and humidity chamber in a gas-phase environment with a temperature between 35°C and 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. The measurement sample is then removed from the constant temperature and humidity chamber. The 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 by the near-infrared spectrometer to calculate the moisture permeation amount [μg]. The average of the five points on the measurement sample is used as the moisture permeation amount for one measurement sample. [Example]

[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 exterior packaging material A for electricity storage devices> Biaxially oriented polyethylene terephthalate (PET) film (12 μm thick) and oriented nylon (ONy) film (15 μm thick) were prepared as the substrate layer. The PET film and ONy film were bonded together using a two-component urethane adhesive (a polyol compound and an aromatic isocyanate compound) and then aged to obtain a substrate layer (30 μm thick) consisting of a PET film (12 μm thick), an adhesive layer (3 μm thick after curing), and an ONy film (15 μm thick) laminated from the outside. Aluminum foil (JIS H4160:1994 A8021H-O (40 μm thick)) was also 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 chromium coating amount of 10 mg / m. 2 (dry mass) was applied to both sides of an aluminum foil by roll coating, and baked.

[0224] Next, 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 onto the barrier layer of the laminate obtained above, to obtain an exterior material for an electricity storage device (total thickness 153 μm) in which the substrate 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 exterior material B for electricity storage devices> A polyethylene terephthalate film (25 μm thick) was prepared as the substrate layer, with the bonding surface subjected to corona treatment. An aluminum alloy foil (JIS H4160:1994 A8021H-O, 40 μm thick) was prepared as the barrier layer. Each of the above films was used as the heat-sealable resin layer. Next, a two-component curing urethane adhesive (polyester polyol and alicyclic isocyanate compound) was used to adhere the substrate layer and barrier layer by dry lamination, producing 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 dry laminate the barrier layer side of the resulting laminate to a film, and an adhesive layer (4 μm) / thermal adhesive resin layer was laminated on the barrier layer. The resulting laminate was then aged and heated to obtain an electrical storage device packaging material B consisting of a laminate in which a base layer / adhesive layer / barrier layer / adhesive layer / thermal adhesive resin layer were laminated in this order. The thermal adhesive resin layer (thickness 40 μm) was formed from a homopolybutylene terephthalate film (unstretched homo PBT: (constituent units are terephthalic acid and 1,4-butanediol)).

[0227] <Preparing the moisture adsorption film> Example 1 A CaO-containing polyethylene sheet (50 μm thick, manufactured by Sasaki Chemical Co., Ltd. under the trade name S-KID) was prepared as the moisture adsorption layer of the moisture adsorption film. A foam sheet (1 mm thick, 24.5 g / cm2) was also 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 to form a moisture adsorption film. 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 adsorption 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 adsorption 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 evaluated 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 the moisture adsorption film.

[0234] <Water permeability evaluation> (Preparation of measurement sample) The test specimens, either the power storage device packaging material A (Examples 1 to 5 and Comparative Example 1) or the power storage device packaging material B (Example 6), were cut into square samples measuring 120 mm in length (MD) × 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. 6 a). Next, the heat-sealable resin layers were heat-sealed along one side facing the center position P (the horizontal direction (TD)) and along the other side perpendicular thereto (the vertical direction (MD)), to form a bag-like sample with an open side in the vertical direction (MD) ( FIG. 6 b). As shown in FIG. 6 b, 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, resulting in a 7 mm width for the heat-sealed portion S. In addition, in the MD direction, a 7 mm wide heat seal bar was shifted and heat sealed twice, 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 packaging material A for an electricity storage device, 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 packaging material B for an electricity storage device, the heat sealing conditions for one side in the horizontal direction (TD direction) were 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 an electricity storage device, the heat sealing conditions for one side in the horizontal direction (TD direction) were 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 an electricity storage device, the heat sealing conditions for one side in the vertical direction (MD direction) were 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 direction) was 3 mm, and then dried in a dry room for 24 hours (Fig. 6c).Next, a 20 mm x 20 mm moisture-absorbing 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 part S was 10 mm, and a measurement sample (packaged body 11 as the test subject) was prepared (Figure 6e).

[0235] (Measurement of moisture permeability) The measurement samples were stored in a thermo-hygrostat chamber under the measurement environment (moisture-containing environment) and measurement time (storage time) listed in Table 1. Additionally, a separate measurement sample was stored in a dry room for reference. The measurement sample was then removed from the thermo-hygrostat chamber. The 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 the five points on the measurement sample was used as the moisture permeation amount for one measurement sample. The average moisture permeation amount and variation 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 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 ) / Storage days (days)

[0236] [Table 1]

[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, from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer; heat-sealing the heat-sealable resin layers together at the periphery of the electrical storage device packaging material to obtain a package; sealing a moisture adsorption film in the package; placing the package with the moisture adsorption film sealed in a moist environment; and measuring the amount of moisture absorbed by the moisture adsorption film in the package, the moisture adsorption film including 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 is clear that the variation in the measured moisture increase amount of the solid moisture absorbent is small, resulting in high accuracy in evaluating the moisture permeability of electrical storage device packaging materials. 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 exterior material for an electricity storage device, comprising: preparing an exterior packaging material for an electricity storage device that is 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 peripheral edge of the exterior packaging material for an electricity storage device; placing the package with the moisture absorbing film sealed in a moist environment; a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the package; It is equipped with The method for evaluating the moisture permeability of an exterior material for an electricity storage device, wherein the moisture adsorption film includes a porous layer. Item 2. The method for evaluating the moisture permeability of an exterior material for an electricity storage device according to Item 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. Item 3. The method for evaluating the moisture permeability of an exterior material for an electricity storage device according to Item 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. Item 4. The method for evaluating 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 gaseous 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 packaging materials for electricity storage devices, comprising: the quality control method targets quality control of an exterior packaging material for an electricity storage device that is 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; an extraction step of extracting a test-target electricity storage device packaging material from the electricity storage device packaging materials; 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 outer packaging material for the test storage device; placing the test subject package with the moisture-absorbing film sealed in a moist environment; a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the test package; a determining 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; It is equipped with The quality control method for an exterior material for an electricity storage device, wherein the moisture adsorption film includes a porous layer. Item 6. 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 / day or less, the packaging material for an electricity storage device is determined to be a non-defective product, or The 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, 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 20 g mm / m 2 / day or less, the packaging material for an electricity storage device is determined to be a non-defective product. Item 6. A quality control method for an electrical storage device packaging material according to Item 5. Item 7. The quality control method for an electrical storage device packaging material according to Item 5 or 6, wherein the electrical storage device packaging material is an all-solid-state battery packaging material or a semi-solid battery packaging material. 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. A method for producing an exterior material for an electricity storage device, The method includes a step of laminating at least a base layer, a barrier layer, and a thermally adhesive resin layer in this order from the outside to obtain a laminate, an extraction step of extracting a test-target electrical storage device packaging material from the electrical storage device packaging material composed of 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 outer packaging material for the test storage device; placing the test subject package with the moisture-absorbing film sealed in a moist environment; a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the test package; a determining 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; It is equipped with The moisture adsorption film includes a porous layer. Item 10. 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 / day or less, the packaging material for an electricity storage device is determined to be a non-defective product, or The 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, 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 20 g mm / m 2 / day or less, the packaging material for an electricity storage device is determined to be a non-defective product. Item 10. A method for producing an exterior material for an electricity storage device according to Item 9. Item 11. The method for producing an exterior material for an electricity storage device according to Item 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. Item 12. The method for producing an exterior packaging material for an electricity storage device 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. 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 material for an electricity storage device, the packaging material being made of a laminate including, in this order from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer, The method for manufacturing the electricity storage device includes: an extraction step of extracting a test electrical storage device packaging material from the electrical storage device packaging materials; 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 outer packaging material for the test storage device; placing the test subject package with the moisture-absorbing film sealed in a moist environment; a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the test package; a determining step of determining whether the packaging material for a test electricity storage device is a non-defective product based on the amount of moisture absorbed by the moisture adsorption film; a step of manufacturing an electricity storage device by housing an electricity storage device element in a package formed from the electricity storage device exterior packaging material; It is equipped with the moisture adsorption film includes a porous layer; If the electrical storage device packaging material is determined to be a non-defective product as a result of the determination process, an electrical storage device element is housed in a packaging body formed from the electrical storage device packaging material to manufacture an electrical storage device. Item 14. 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 / day or less, the packaging material for an electricity storage device is determined to be a non-defective product, or The 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, 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 20 g mm / m 2 / day or less, the packaging material for an electricity storage device is determined to be a non-defective product. Item 14. A method for producing the electricity storage device according to item 13. Item 15. The method for producing an electricity storage device according to Item 13 or 14, wherein the electricity storage device packaging material is an all-solid-state battery packaging material or a semi-solid-state battery packaging material. Item 16. The method for producing 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 test package, and the amount of moisture absorbed by the moisture adsorption film in the test package is measured. Item 17. A moisture adsorption film used in a method for evaluating the moisture permeability of packaging materials for electric storage devices, the moisture adsorption film includes a porous layer; The method for evaluating the moisture permeability of the packaging material for an electricity storage device includes: preparing the 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 thermally adhesive 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 peripheral edge of the exterior packaging material for an electricity storage device; placing the package with the moisture absorbing film sealed in a moist environment; a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the package; A moisture-absorbing film. Item 18. An exterior packaging material for an electricity storage device, which is 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, The moisture permeability coefficient calculated using the measurement method below is 10g·mm / m 2 / day or less exterior material for energy storage devices. an extraction step of extracting a test-target electricity storage device packaging material from the electricity storage device packaging materials; a sealing step of sealing a moisture adsorption film including a porous layer in a test package obtained by heat-sealing the heat-sealable resin layers together at the periphery of the outer packaging material for the test electricity storage device; placing the test subject package with the moisture-absorbing film sealed in a moist environment; a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the test package; a calculation step of calculating a moisture permeability coefficient from the heat-sealed portion between the heat-sealable resin layers of the package to be tested based on the amount of moisture absorbed by the moisture adsorption film; Equipped with 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. [Explanation of symbols]

[0240] 1 Base material layer 2 Adhesive layer 3 Barrier layer 4 Heat-fusible resin layer 5 Adhesive layer 6 Surface coating layer 10, 50 Exterior materials for energy storage devices 11, 40 packaging A. Moisture absorption film P Center position S Heat-sealed part 10a Peripheral edge of the exterior material for the electricity storage device 12 Energy storage devices 13 Energy storage device element 14 Adhesive film 15 Metal terminal 20 Electrode body 30 Moisture absorption film 31 Porous layer 32 Moisture absorption layer 33 Adhesive layer 60 Lid 70 First sealing portion 80 Second sealing portion

Claims

[Claim 1] A method for evaluating moisture permeability of an exterior material for an electricity storage device, comprising: preparing an exterior packaging material for an electricity storage device that is 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 peripheral edge of the exterior packaging material for an electricity storage device; placing the package with the moisture absorbing film sealed in a moist environment; a moisture amount measuring step of measuring the amount of moisture absorbed by the moisture adsorption film in the package; It is equipped with The method for evaluating the moisture permeability of an exterior material for an electricity storage device, wherein the moisture adsorption film includes a porous layer.

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