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

Abstract

Provided is an exterior material for an electrical storage device, the material having suppressed curling caused by molding and having high mechanical strength irrespective of having a thickness of as thin as 100 μｍ or less.　This exterior material for an electrical storage device comprises a laminate provided with at least a base material layer, a barrier layer, and a thermally fusible resin layer in this order. The thickness of the base material layer is 18-22 μｍ, the thickness of the barrier layer is 27-38 μｍ, and the thickness of the laminate is 100 μｍ or less.

Description

[Technical Field]

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

[0002] Various types of electricity storage devices have been developed, but in all of them, packaging materials (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., electricity storage devices are being required 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 packaging material in which a substrate / aluminum foil layer / thermally adhesive resin layer are laminated in this order has been proposed as a packaging 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 film-like packaging materials, recesses are generally formed by cold forming, and energy storage device elements such as electrodes and electrolyte are placed in the spaces formed by the recesses. The heat-sealable resin layers are then heat-sealed together to obtain an energy storage device in which the energy storage device elements are housed inside the 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 recent years, there has been a demand for thinner film packaging materials. Also, from the perspective of further increasing the energy density of electricity storage devices, there is a demand for the formation of deeper recesses in packaging materials.

[0008] However, the inventors of the present disclosure have found that when an outer casing material for an electricity storage device is made by laminating a base material layer, a barrier layer, and a heat-sealable resin layer in that order, and this is molded to form a recess for accommodating an electricity storage device element, if the thickness of the outer casing material for an electricity storage device is reduced to 100 μm or less, the peripheral edge of the recess may curl (bend) during molding, hindering the accommodation of the electricity storage device element and the heat-sealing of the heat-sealable resin layer, and possibly reducing the production efficiency of the electricity storage device.

[0009] In particular, in the case of electricity storage devices used in small devices such as personal computers, cameras, and mobile phones, it is necessary to form deep recesses with small areas in thin exterior materials, and curling due to molding can become significant.

[0010] Furthermore, if the thickness of the exterior packaging material for an electricity storage device is reduced to 100 μm or less, the mechanical strength decreases, and there is a risk that the electricity storage device elements may not be adequately protected, for example, when an external impact is applied to the electricity storage device (for example, when the electricity storage device is dropped).

[0011] Under these circumstances, a main object of the present disclosure is to provide an exterior material for an electricity storage device that is suppressed from curling during molding and has high mechanical strength, despite having a thickness of 100 μm or less. [Means for solving the problem]

[0012] In order to solve the above-mentioned problems, the present inventors have conducted extensive research into suppressing curl during molding and improving mechanical strength in an electrical storage device packaging material designed to have a thickness of 100 μm or less, focusing on the laminate structure of the electrical storage device packaging material. As a result, they have found that it is possible to provide an electrical storage device packaging material that suppresses curl during molding and has high mechanical strength compared to conventional electrical storage device packaging materials. Specifically, they have found that by setting the total thickness of the laminate constituting the electrical storage device packaging material to 100 μm or less, setting the thickness of the base layer to be 18 μm or more and 22 μm or less, and setting the thickness of the barrier layer to be 27 μm or more and 38 μm or less, it is possible to obtain an electrical storage device packaging material that is thin, suppresses curl during molding, and has high mechanical strength.

[0013] 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. The laminate is composed of at least a base layer, a barrier layer, and a heat-sealable resin layer in this order, The thickness of the base layer is 18 μm or more and 22 μm or less, the thickness of the barrier layer is 27 μm or more and 38 μm or less; The laminate has a thickness of 100 μm or less. [Effects of the Invention]

[0014] According to the present disclosure, it is possible to provide an electrical storage device packaging material that is suppressed from curling during molding and has high mechanical strength despite having a thin thickness of 100 μm or less. The present disclosure can also provide a method for manufacturing an electrical storage device packaging material, and an electrical storage device. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. [Figure 2] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. [Figure 3] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. [Figure 4] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. [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 evaluating curling due to molding of an exterior material for an electricity storage device. [Figure 7] FIG. 2 is a schematic diagram illustrating a method for evaluating curling due to molding of an exterior material for an electricity storage device. DETAILED DESCRIPTION OF THE INVENTION

[0016] The packaging material for an electricity storage device of the present disclosure is composed of a laminate including at least a base layer, a barrier layer, and a heat-sealable resin layer in this order, and is characterized in that the thickness of the base layer is 18 μm or more and 22 μm or less, the thickness of the barrier layer is 27 μm or more and 38 μm or less, and the thickness of the laminate is 100 μm or less. By having such a configuration, the packaging material for an electricity storage device of the present disclosure is suppressed from curling during molding, despite its thin thickness of 100 μm or less, and further has high mechanical strength.

[0017] The exterior packaging material for an electricity storage device of the present disclosure will be described in detail below. In this specification, a numerical range indicated by "to" means "greater than or equal to" or "less than or equal to." For example, the expression "2 to 15 mm" means 2 mm or more and 15 mm or less. In this specification, the thickness of each layer constituting the laminate is rounded to one decimal place.

[0018] 1.Layer structure and physical properties of exterior materials for energy storage devices As shown in FIG. 1 , for example, the electrical storage device packaging material 10 of the present disclosure is composed of a laminate including a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4 in this order. 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.

[0019] 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. Specific examples of the laminated structure of the exterior packaging material 10 for an electricity storage device include a laminated structure in which a substrate layer 1, a barrier layer 3, and a heat-sealable resin layer 4 are laminated in this order; a laminated structure in which a substrate layer 1, an adhesive layer 2, a barrier layer 3, and a heat-sealable resin layer 4 are laminated in this order; a laminated structure in which a substrate layer 1, a barrier layer 3, an adhesive layer 5, and a heat-sealable resin layer 4 are laminated in this order; a laminated structure in which a substrate layer 1, an adhesive layer 2, a barrier layer 3, an adhesive layer 5, and a heat-sealable resin layer 4 are laminated in this order; a laminated structure in which a surface coating layer 6, a substrate layer 1, a barrier layer 3, and a heat-sealable resin layer 4 are laminated in this order; a laminated structure in which a surface coating layer 6, a substrate layer 1, an adhesive layer 2, a barrier layer 3, and a heat-sealable resin layer 4 are laminated in this order; a laminated structure in which a surface coating layer 6, a substrate layer 1, a barrier layer 3, an adhesive layer 5 ... In a laminated structure in which the base layer 1 is the outermost layer, a lubricant may be present on at least one of the outer surface of the base layer 1 and the inner surface of the heat-sealable resin layer 4. In addition, in a laminated structure in which the surface coating layer 6 is the outermost layer, a lubricant may be present on at least one of the outer surface of the surface coating layer 6 and the inner surface of the heat-sealable resin layer 4. Lubricants will be described later.

[0020] The thickness of the laminate constituting the electrical storage device packaging material of the present disclosure is set to 100 μm or less. In the electrical storage device packaging material of the present disclosure, by setting the thickness of the laminate to 100 μm or less and setting the thicknesses of the substrate layer 1 and barrier layer 3 described below within specific ranges, the electrical storage device packaging material is suppressed from curling during molding despite its thin thickness, and has high mechanical strength. From the viewpoints of suitably suppressing curling during molding while making the electrical storage device packaging material as thin as possible and further suitably exhibiting high mechanical strength, the thickness of the laminate is preferably about 75 μm or more, more preferably about 77 μm or more, even more preferably about 80 μm or more, even more preferably about 85 μm or more, and even more preferably about 88 μm or more. From the same viewpoint, the thickness of the laminate is preferably about 98 μm or less, more preferably about 95 μm or less, even more preferably about 93 μm or less, and even more preferably about 91 μm or less. Preferred ranges for the thickness of the laminate include about 75 to 100 μm, about 75 to 98 μm, about 75 to 95 μm, about 75 to 93 μm, about 75 to 91 μm, about 77 to 100 μm, about 77 to 98 μm, about 77 to 95 μm, about 77 to 93 μm, about 77 to 91 μm, about 80 to 100 μm, about 80 to 98 μm, about 80 to 95 μm, about 80 to 93 μm, about 80 to 91 μm, about 85 to 100 μm, about 85 to 98 μm, about 85 to 95 μm, about 85 to 93 μm, about 85 to 91 μm, about 88 to 100 μm, about 88 to 98 μm, about 88 to 95 μm, about 88 to 93 μm, and about 88 to 91 μm.

[0021] In the packaging material for an electricity storage device of the present disclosure, the ratio of the total thickness of the base material layer 1, the adhesive layer 2 (if provided as needed), the barrier layer 3, the adhesive layer 5 (if provided as needed), the heat-sealable resin layer 4, and the surface coating layer 6 (if provided as needed) to the thickness (total thickness) of the laminate constituting the packaging material 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 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 for an electricity storage device 10 is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more. Furthermore, even when the packaging material for an electricity storage device of the present disclosure includes 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 for an electricity storage device 10 is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.

[0022] In the packaging material for an electricity storage device according to the present disclosure, the total thickness of the layers located inside the barrier layer 3 (on the thermally adhesive resin layer 4 side) is preferably at least about 20 μm, more preferably at least about 22 μm, even more preferably at least about 24 μm, and even more preferably at least about 28 μm. The total thickness is preferably no more than about 40 μm, more preferably no more than about 38 μm, and even more preferably no more than about 35 μm. Preferred ranges for the total thickness include about 20 to 40 μm, about 20 to 38 μm, about 20 to 35 μm, about 22 to 40 μm, about 22 to 38 μm, about 22 to 35 μm, about 24 to 40 μm, about 24 to 38 μm, about 24 to 35 μm, about 28 to 40 μm, about 28 to 38 μm, and about 28 to 35 μm.

[0023] The thickness of each layer of the electrical storage device packaging material or the thickness of the laminate of the present disclosure can be measured by, for example, cutting the electrical storage device packaging material in the thickness direction using a microtome (REM-710 lithratome, manufactured by Yamato Koki Kogyo Co., Ltd.), dividing the electrical storage device packaging material into two, and observing the resulting cross section with, for example, a laser microscope (VK-9700, manufactured by Keyence Corporation).

[0024] 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 aluminum foil, linear streaks called rolling marks are formed on the surface of the aluminum foil in the rolling direction (RD) of the aluminum foil. Since the rolling marks extend along the rolling direction, the rolling direction of the aluminum foil can be determined by observing the surface of the aluminum foil. Furthermore, during the manufacturing process of a laminate, the MD of the laminate usually coincides with the RD of the aluminum foil, so the MD of the laminate can be identified by observing the surface of the aluminum foil of the laminate and identifying the rolling direction (RD) of the aluminum 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.

[0025] The puncture strength from the outer surface side (substrate layer side or surface coating layer side) of the laminate constituting the electrical storage device packaging material is preferably 19 N or more, more preferably 23 N or more. The puncture strength is, for example, 30 N or less. The puncture strength is adjusted, for example, by the laminate structure of the electrical storage device packaging material, the thickness of the substrate layer 1, the stretch ratio during production of the substrate layer 1, the heat setting temperature, etc. The puncture strength is measured by the following method.

[0026] <Puncture Strength> The puncture strength from the outer surface side (substrate layer side or surface coating layer side) of the laminate constituting the exterior material for an electricity storage device is measured using a method in accordance with the provisions of JIS Z1707:1997. Measurement equipment that can be used includes, for example, Imada's ZP-50N (force gauge) and Imada's MX2-500N (measuring stand). In a measurement environment of 23±2°C and 50±5% relative humidity, a test specimen is fixed using a 115mm diameter base with a 15mm diameter opening in the center and a pressure plate. A semicircular needle with a 1.0mm diameter and a 0.5mm tip radius is pierced at a rate of 50±5mm per minute, and the maximum stress until the needle penetrates is measured. Ten test specimens are measured for each test, and the average value is calculated. If there are not enough test specimens to measure 10, the number of test specimens that can be measured is measured and the average value is calculated. If the puncture strength is 19N or more, the mechanical strength is sufficiently high, and if it is 23N or more, the mechanical strength is particularly high.

[0027] The dynamic friction coefficient of the outer surface (the surface on the substrate layer side or the surface coating layer side) of the electrical storage device packaging material is preferably about 0.01 or more, more preferably about 0.05 or more, and even more preferably about 0.09 or more. The dynamic friction coefficient is preferably about 0.80 or less, more preferably about 0.50 or less, and even more preferably about 0.25 or less. Preferred ranges for the dynamic friction coefficient include about 0.01 to 0.80, about 0.01 to 0.50, about 0.01 to 0.25, about 0.05 to 0.80, about 0.05 to 0.50, about 0.05 to 0.25, about 0.09 to 0.80, about 0.09 to 0.50, and about 0.09 to 0.25. The dynamic friction coefficient is adjusted by the material and lubricant of the layers constituting the outer surface of the electrical storage device packaging material. The dynamic friction coefficient is measured as follows.

[0028] <Dynamic friction coefficient> The dynamic friction coefficient was measured using a method based on JIS K7125:1999, Section 8.1, Film-to-Film Measurement. Two samples measuring 80 mm in the TD direction and 200 mm in the MD direction were cut from the exterior material for the energy storage device. Next, the samples were stacked with their outer surfaces facing each other, and a slider was placed on top of them. Rubber was attached to the bottom of the slider, with a total mass of 200 g. The sample and slider were closely attached to prevent slippage. The slider was then pulled at a speed of 100 mm / min, and the dynamic friction force (N) between the two samples was measured. The dynamic friction force was divided by the normal force of the slider (1.96 N) to calculate the dynamic friction coefficient. The dynamic friction coefficient was calculated by ignoring the peak static friction force and averaging it over the first 30 mm after the start of the relative shear movement between the contact surfaces. The load cell was directly connected to the slider.

[0029] Furthermore, when the packaging material for an electricity storage device according to the present disclosure is subjected to the following four-fold test, it is preferably folded five or more times, more preferably seven or more times, before a pinhole is formed in the center. If the folding number is five or more times, it can be said that the mechanical strength of the packaging material for an electricity storage device is sufficiently high, and if it is folded seven or more times, it can be said that the mechanical strength of the packaging material for an electricity storage device is particularly high.

[0030] <Four-fold test> The exterior material for an energy storage device was cut into strips measuring 150 mm in TD x 90 mm in MD, which served as test samples. The test sample was folded into four 10 times, and the number of times it was folded until a pinhole formed in the center was measured. The test sample was folded into four by first folding it in half at the center in the TD so that the short edges (edges in the MD) of the test sample overlapped, and then folding it in half again at the center in the MD so that the edges in the TD overlapped, resulting in a quarter-fold at the center of the test sample. This counts as one quarter-fold. The test sample was then unfolded, and the same four-folding and unfolding process was repeated to conduct the test. Five test samples were used for each test, and the average number of times it took for a pinhole to form in the center was calculated. If there were not enough test samples to measure five, the number of measurements that could be made was measured, and the average was calculated.

[0031] 2. Each layer that forms the exterior material for the energy storage device [Base material layer 1] In the present disclosure, the substrate layer 1 is a layer provided for the purpose of, for example, exhibiting the function as a substrate of the packaging material for an electricity storage device. The substrate layer 1 is located on the outer layer side of the packaging material for an electricity storage device. The substrate layer 1 may be the outermost layer (the layer that constitutes the outer surface), or, for example, when a surface coating layer 6 described below is provided, the surface coating layer 6 may be the outermost layer (the layer that constitutes the outer surface).

[0032] One of the features of the electrical storage device packaging material of the present disclosure is that the thickness of the substrate layer 1 is set to a specific range of 18 to 22 μm. From the viewpoint of suitably suppressing curling during molding and suitably exhibiting high mechanical strength despite the thin thickness of the electrical storage device packaging material, the thickness of the substrate layer 1 is preferably about 19 μm or more. From the same viewpoint, the thickness of the substrate layer 1 is preferably about 21 μm or less. Preferred ranges for the thickness of the substrate layer 1 include about 18 to 21 μm, about 19 to 22 μm, and about 19 to 21 μm. Note that in the present disclosure, when the substrate layer 1 is composed of two or more layers and these layers are bonded together with an adhesive layer such as an adhesive layer, the thickness of the adhesive layer is not included in the overall thickness of the substrate layer 1.

[0033] 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.

[0034] When the base layer 1 is formed of a resin, the base layer 1 may be, for example, a resin film formed of a resin, or may be formed by applying a resin. The resin film may be an unstretched film or a stretched film. Examples of stretched films include uniaxially stretched films and biaxially stretched films, with biaxially stretched films being preferred. Examples of stretching methods for forming biaxially stretched films include sequential biaxial stretching, inflation, and simultaneous biaxial stretching. Examples of methods for applying a resin include roll coating, gravure coating, and extrusion coating.

[0035] 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.

[0036] Of these, preferred resins for forming the base layer 1 include polyester and polyamide.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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 film and polyamide film, or a laminate of polyester resin film and polyamide 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.

[0042] When the base layer 1 is a laminate of two or more resin film layers, the two or more resin film layers may be laminated via an adhesive. Examples of preferred adhesives include those similar to those exemplified for adhesive layer 2 described below. The method for laminating two or more resin film layers is not particularly limited, and known methods can be used, such as dry lamination, sandwich lamination, extrusion lamination, and thermal lamination, with dry lamination being preferred. When laminating using the dry lamination method, it is preferable to use a polyurethane adhesive as the adhesive. In this case, the thickness of the adhesive is, for example, about 2 to 5 μm. Alternatively, an anchor coat layer may be formed on the resin film before lamination. Examples of the anchor coat layer include those similar to those exemplified for adhesive layer 2 described below. In this case, the thickness of the anchor coat layer is, for example, about 0.01 to 1.0 μm. The thickness of the anchor coat layer is not included in the thickness of the base layer 1.

[0043] From the viewpoint of suitably suppressing curling during molding and suitably exhibiting high mechanical strength despite the thin thickness of the exterior material for an electricity storage device, it is preferable that the base material layer 1 be made of a single-layer nylon film.

[0044] When the base material layer 1 contains a polyamide film, the crystallization index of the polyamide film measured from the outside of the base material layer 1 by the ATR method of Fourier transform infrared spectroscopy is preferably 1.50 or more. The method for measuring the crystallization index of the base material layer 1 of the electrical storage device packaging material 10 of the present disclosure is as follows.

[0045] <Measurement of the crystallization index of the base material layer of the exterior material for an electricity storage device> The exterior material for a power storage device is cut into a 100 mm x 100 mm square to prepare a sample. The surface of the polyamide film located on the outside of the obtained sample is subjected to infrared absorption spectrum measurement using the ATR measurement mode of FT-IR under an environment of a temperature of 25°C and a relative humidity of 50%. As an apparatus, for example, a Nicolet iS10 manufactured by Thermo Fisher Scientific Inc. can be used. From the obtained absorption spectrum, a 1200 cm -1 The peak intensity P near 1370 cm originates from absorption unrelated to crystals. -1 The peak intensity Q near the peak intensity P is measured, and the intensity ratio X=P / Q of the peak intensity P to the peak intensity Q is calculated as the crystallization index. When obtaining an electrical storage device packaging material from an electrical storage device to measure the crystallization index of the base material layer, the sample is prepared by obtaining the electrical storage device packaging material from the top or bottom surface, rather than from the heat-sealed portion or side surface of the electrical storage device. (Measurement conditions) Method: Macro ATR method Wavenumber resolution: 8cm -1 Accumulation count: 32 times Detector: DTGS detector ATR prism: Ge Incident angle: 45° Baseline: Wavenumber 1100cm-1 From 1400cm -1 The curve was calculated as a linear approximation between the two. Absorption peak intensity Y 1200 : Wave number 1195cm -1 From 1205cm -1 The maximum peak intensity in the range minus the baseline value Absorption peak intensity Y 1370 : Wave number 1365cm -1 From 1375cm -1 The maximum peak intensity in the range minus the baseline value

[0046] When the outer surface of the electricity storage device packaging material 10 is made up of the polyamide film of the base material layer 1, the crystallization index can be measured directly for the electricity storage device packaging material 10. When the outer surface of the electricity storage device packaging material 10 is not made up of the polyamide film of the base material layer 1, such as when the base material layer 1 has a multilayer structure as described above and a resin film other than the polyamide film (for example, a polyester film) is located outside the polyamide film, or when a surface coating layer 6 described below is laminated on the outside of the base material layer 1, the layer located outside the polyamide film can be removed from the electricity storage device packaging material 10 to expose the surface of the polyamide film, and the crystallization index can be measured.

[0047] In the electrical storage device packaging material 10, the crystallization index may be 1.50 or more. However, from the viewpoint of suitably suppressing curling during molding and suitably exhibiting high mechanical strength despite the thin thickness of the electrical storage device packaging material, the crystallization index is more preferably 1.55 or more, even more preferably 1.60 or more, even more preferably 1.65 or more, and particularly preferably 1.69 or more. The upper limit of the crystallization index is not particularly limited, but examples include 2.50 or less and 1.80 or less. Preferred ranges of the crystallization index include, for example, 1.50 to 2.50, 1.60 to 2.50, 1.65 to 2.50, 1.69 to 2.50, 1.50 to 1.80, 1.60 to 1.80, 1.65 to 1.80, and 1.69 to 1.80.

[0048] Methods for increasing the crystallization index of the polyamide film contained in the base material layer 1 of the packaging material 10 for an electrical storage device to 1.50 or more include promoting crystallization (promoting the production of α crystals) by adjusting the stretching ratio, heat setting temperature, and even the post-heating temperature and time during the polyamide film manufacturing process.

[0049] Furthermore, additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, and antistatic agents may be present on at least one of the surface and the interior of the base material layer 1. Only one type of additive may be used, or two or more types may be mixed and used.

[0050] In the present disclosure, from the viewpoint of improving the formability of the exterior material for an electrical storage device, it is preferable that a lubricant be present on the surface of the base layer 1. The lubricant is not particularly limited, but preferably an amide-based lubricant is used. Specific examples of amide-based lubricants include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides. Specific examples of saturated fatty acid amides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide. Specific examples of unsaturated fatty acid amides include oleic acid amide and erucic acid amide. Specific examples of substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide. Specific examples of methylolamides include methylol stearic acid amide. Specific examples of saturated fatty acid bisamides include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipamide, and N,N'-distearyl sebacic acid amide. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipamide, and N,N'-dioleyl sebacic acid amide. Specific examples of fatty acid ester amides include stearamidoethyl stearate. Specific examples of aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, N,N'-distearyl isophthalic acid amide, etc. The lubricants may be used singly or in combination of two or more.

[0051] When a lubricant is present on the surface of the base layer 1, the amount of the lubricant is not particularly limited, but is preferably about 3 mg / m 2 or more, more preferably 4 to 15 mg / m 2 approximately, more preferably 5 to 14 mg / m 2 The degree of

[0052] The lubricant present on the surface of the base layer 1 may be a lubricant exuded from the resin constituting the base layer 1, or a lubricant applied to the surface of the base layer 1. The lubricant present on the surface of the base layer 1 may also be a lubricant that was present on the surface of the heat-fusible resin layer 4 and has been transferred to the surface of the base layer 1 when the electrical storage device packaging material is in a wound state in which it is wound around a core or the like.

[0053] [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.

[0054] 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.

[0055] 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.

[0056] Examples of polyurethane adhesives include polyurethane adhesives containing a base agent containing a polyol compound and a curing agent containing an isocyanate compound. Two-component curing polyurethane adhesives are preferred, using a polyol such as polyester polyol, polyether polyol, or acrylic polyol as the base agent and an aromatic or aliphatic polyisocyanate as the curing agent. Furthermore, polyester polyols having hydroxyl groups on the side chains in addition to terminal hydroxyl groups in the repeating units are preferred as polyol compounds. Examples of curing agents 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). Further examples include polyfunctional isocyanate modified products obtained from one or more of these diisocyanates. Furthermore, a polymer (e.g., a trimer) can also be used as the polyisocyanate compound. Examples of such polymers include adducts, biurets, and nurates. Forming the adhesive layer 2 from a polyurethane adhesive provides the electrical storage device exterior packaging material with excellent electrolyte resistance, and prevents the base layer 1 from peeling off even if the electrolyte adheres to the side surface.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] The average particle size of the pigment is not particularly limited and may be, for example, about 0.05 to 5 μm, and preferably about 0.08 to 2 μm. The average particle size of the pigment is the median size measured with a laser diffraction / scattering particle size distribution measuring device.

[0061] The content of the pigment in the adhesive layer 2 is not particularly limited as long as it colors the packaging material for an electricity storage device, and may be, for example, about 5 to 60 mass %, and preferably 10 to 40 mass %.

[0062] 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.

[0063] [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.

[0064] 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.

[0065] Specific examples of the colorant contained in the colored layer include the same as those exemplified in the section [Adhesive layer 2].

[0066] [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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] One of the features of the electrical storage device packaging material of the present disclosure is that the thickness of the barrier layer 3 is set to a specific range of 27 to 38 μm. From the viewpoint of suitably suppressing curling during molding and suitably exhibiting high mechanical strength despite the thin thickness of the electrical storage device packaging material, the thickness of the barrier layer 3 is preferably 28 μm or more, more preferably about 30 μm or more, and even more preferably 33 μm or more. From the same viewpoint, the thickness of the barrier layer is preferably 37 μm or less, more preferably 36 μm or less. Preferred ranges for the thickness of the barrier layer include about 27 to 37 μm, about 27 to 36 μm, about 28 to 38 μm, about 28 to 37 μm, about 28 to 36 μm, about 30 to 38 μm, about 30 to 37 μm, about 30 to 36 μm, about 33 to 38 μm, about 33 to 37 μm, and about 33 to 36 μm.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] [ka]

[0076] [ka]

[0077] [ka]

[0078] [ka]

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] The composition of the corrosion-resistant film can be analyzed using, for example, time-of-flight secondary ion mass spectrometry.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] [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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] Acid-modified polyolefins are polymers modified by block polymerization or graft polymerization of polyolefins with an acid component. Examples of acid-modified polyolefins include the above-mentioned polyolefins, copolymers of the above-mentioned polyolefins with polar molecules such as acrylic acid or methacrylic acid, and crosslinked polyolefins. Examples of acid components used for acid modification include carboxylic acids or anhydrides thereof, such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] Furthermore, the heat-sealable resin layer 4 may contain a lubricant, etc., as necessary. When the heat-sealable resin layer 4 contains a lubricant, the moldability of the electrical storage device packaging material can be improved. The lubricant is not particularly limited, and known lubricants can be used. The lubricants may be used alone or in combination of two or more.

[0096] 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.

[0097] When a lubricant is present on the surface of the heat-sealable resin layer 4, the amount of the lubricant present is not particularly limited, but from the viewpoint of improving the formability of the packaging material for an electricity storage device, it is preferably 10 to 50 mg / m 2 about 15 to 40 mg / m 2 The degree of

[0098] 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.

[0099] The thickness of the heat-sealable resin layer 4 can be set depending on the presence or absence of the adhesive layer 5 and the thickness of the adhesive layer 5, while setting the thickness of the laminate constituting the packaging material for an electricity storage device, the thickness of the base layer 1, and the thickness of the barrier layer 3 to the predetermined thicknesses. The thickness of the heat-sealable resin layer 4 is, for example, about 33 μm or less, about 30 μm or less, about 20 μm or less, about 17 μm or less, or about 15 μm or less. The thickness of the heat-sealable resin layer 4 is, for example, about 8 μm or more, about 10 μm or more, about 15 μm or more, about 20 μm or more, about 22 μm or more, about 25 μm or more, or about 28 μm or more. Preferred ranges for the thickness of the heat-sealable resin layer 4 are about 8 to 33 μm, about 8 to 30 μm, about 8 to 20 μm, about 8 to 17 μm, about 8 to 15 μm, about 10 to 33 μm, about 10 to 30 μm, about 10 to 20 μm, about 10 to 17 μm, about 10 to 15 μm, about 15 to 33 μm, about 15 to 30 μm, about 15 to 20 μm, about 15 to 17 μm, about 20 to 33 μm, about 20 to 30 μm, about 22 to 33 μm, about 22 to 30 μm, about 25 to 33 μm, about 25 to 30 μm, about 28 to 33 μm, and about 28 to 30 μm.

[0100] In particular, when the thickness of adhesive layer 5 described below is within the range of 12 to 17 μm, the thickness of heat-sealable resin layer 4 is preferably about 17 μm or less, more preferably about 15 μm or less. Furthermore, when the thickness of adhesive layer 5 described below is within the range of 12 to 17 μm, the thickness of heat-sealable resin layer 4 is preferably about 8 μm or more, more preferably 10 μm or more. When the thickness of adhesive layer 5 described below is within the range of 12 to 17 μm, preferred ranges for the thickness of heat-sealable resin layer 4 include about 8 to 17 μm, about 8 to 15 μm, about 10 to 17 μm, and about 10 to 15 μm.

[0101] Furthermore, when the thickness of adhesive layer 5 described below is within the range of 1 to 5 μm, the thickness of heat-sealable resin layer 4 is preferably about 22 μm or more, more preferably about 25 μm or more, and even more preferably about 28 μm or more. Furthermore, when the thickness of adhesive layer 5 described below is within the range of 1 to 5 μm, the thickness of heat-sealable resin layer 4 is preferably about 33 μm or less, more preferably about 30 μm or less. When the thickness of adhesive layer 5 described below is within the range of 1 to 5 μm, the preferred ranges for the thickness of heat-sealable resin layer 4 are about 22 to 33 μm, about 22 to 30 μm, about 25 to 33 μm, about 25 to 30 μm, about 28 to 33 μm, and about 28 to 30 μm.

[0102] [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.

[0103] The adhesive layer 5 is formed of a resin capable of bonding the barrier layer 3 and the heat-sealable resin layer 4. Examples of resins that can be used to form the adhesive layer 5 include the same adhesives as those exemplified for the adhesive layer 2. From the viewpoint of firmly bonding the adhesive layer 5 and the heat-sealable resin layer 4, the resin used to form the adhesive layer 5 preferably contains a polyolefin skeleton, such as the polyolefins and acid-modified polyolefins exemplified for the heat-sealable resin layer 4. From the viewpoint of firmly bonding the barrier layer 3 and the adhesive layer 5, the adhesive layer 5 preferably contains an acid-modified polyolefin. Examples of acid-modified components include dicarboxylic acids such as maleic acid, itaconic acid, succinic acid, and adipic acid, as well as anhydrides thereof, acrylic acid, and methacrylic acid. However, from the viewpoints of ease of modification and versatility, maleic anhydride is most preferred. From the viewpoint of the heat resistance of the electrical storage device exterior material, the olefin component is preferably a polypropylene-based resin, and the adhesive layer 5 most preferably contains maleic anhydride-modified polypropylene.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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, biuret compounds, and isocyanurates.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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 first 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] The adhesive layer 5 may contain a modifier having a carbodiimide group.

[0119] The thickness of the adhesive layer 5 can be set according to the thickness of the heat-sealable resin layer 4, while setting the thickness of the laminate constituting the packaging material for an electricity storage device, the thickness of the base material layer 1, and the thickness of the barrier layer 3 to the predetermined thicknesses. The thickness of the adhesive layer 5 is, for example, about 17 μm or less, about 16 μm or less, about 15 μm or less, about 8 μm or less, about 5 μm or less, about 3 μm or less, etc. The thickness of the adhesive layer 5 is, for example, about 1 μm or more, about 3 μm or more, about 8 μm or more, about 10 μm or more, about 12 μm or more, about 15 μm or more, etc. Preferred ranges for the thickness of the adhesive layer are, for example, about 1 to 17 μm, about 1 to 16 μm, about 1 to 15 μm, about 1 to 8 μm, about 1 to 5 μm, about 1 to 3 μm, about 3 to 17 μm, about 3 to 16 μm, about 3 to 15 μm, about 3 to 8 μm, about 3 to 5 μm, about 8 to 17 μm, about 8 to 16 μm, about 8 to 15 μm, about 10 to 17 μm, about 10 to 16 μm, about 10 to 15 μm, about 12 to 17 μm, about 12 to 16 μm, about 12 to 15 μm, about 15 to 17 μm, and about 15 to 16 μm.

[0120] In particular, when the thickness of the heat-sealable resin layer 4 is 8 to 17 μm, the thickness of the adhesive layer 5 is preferably about 12 μm or more, more preferably about 15 μm or more. When the thickness of the heat-sealable resin layer 4 is 8 to 17 μm, the thickness of the adhesive layer 5 is preferably about 17 μm or less, more preferably about 16 μm or less. When the thickness of the heat-sealable resin layer 4 is 8 to 17 μm, the preferred ranges for the thickness of the adhesive layer 5 are about 12 to 17 μm, about 12 to 16 μm, about 15 to 17 μm, and about 15 to 16 μm.

[0121] Furthermore, when the thickness of the heat-sealable resin layer 4 is 22 to 33 μm, the thickness of the adhesive layer 5 is preferably about 5 μm or less. Furthermore, when the thickness of the heat-sealable resin layer 4 is 22 to 33 μm, the thickness of the adhesive layer 5 is preferably about 1 μm or more, more preferably about 3 μm or more. In this case, it is preferable to use an acid-modified polyolefin exemplified for the heat-sealable resin layer 4 as the adhesive layer 5. When the thickness of the heat-sealable resin layer 4 is 22 to 33 μm, the preferred range for the thickness of the adhesive layer 5 is about 1 to 5 μm, or about 3 to 5 μm. In this case, it is preferable to use, as the adhesive layer 5, a cured product of an acid-modified polyolefin and a curing agent, or an adhesive similar to the adhesive exemplified for the adhesive layer 2.

[0122] [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.

[0123] The surface coating layer 6 can be formed from a resin such as polyvinylidene chloride, polyester, polyurethane, acrylic resin, or epoxy resin.

[0124] 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.

[0125] Examples of two-component curing polyurethanes include polyurethanes containing a polyol compound as a base component and an isocyanate compound as a curing agent. Preferred examples of two-component curing polyurethanes include those using a polyol such as polyester polyol, polyether polyol, or acrylic polyol as a base component and an aromatic or aliphatic polyisocyanate as a curing agent. Furthermore, as the polyol compound, polyester polyols having hydroxyl groups on the side chains in addition to terminal hydroxyl groups in the repeating units are preferably used. Examples of curing agents 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). Further examples include polyfunctional isocyanate modified products obtained from one or more of these diisocyanates. Furthermore, a polymer (e.g., a trimer) can also be used as the polyisocyanate compound. Examples of such polymers include adducts, biurets, and nurates. The aliphatic isocyanate compound refers to an isocyanate having an aliphatic group but no aromatic ring, the alicyclic isocyanate compound refers to an isocyanate having an alicyclic hydrocarbon group, and the aromatic isocyanate compound refers to an isocyanate having an aromatic ring. The surface coating layer 6 is formed from polyurethane, which provides the exterior material for an electricity storage device with excellent electrolyte resistance.

[0126] The thickness of the surface coating layer 6 is not particularly limited as long as it exhibits the above-described functions as the surface coating layer 6 and the thicknesses of the laminate constituting the electrical storage device packaging material, the base layer 1, and the barrier layer 3 are set to the predetermined thicknesses, but is, for example, about 0.1 μm or more, about 0.5 μm or more, about 1 μm or more, or about 2 μm or more. The thickness of the surface coating layer 6 is, for example, about 5 μm or less, about 4 μm or less, or about 3 μm or less. Preferred ranges for the thickness of the surface coating layer 6 include about 0.1 to 5 μm, about 0.1 to 4 μm, about 0.1 to 3 μm, about 0.5 to 5 μm, about 0.5 to 4 μm, about 0.5 to 3 μm, about 1 to 5 μm, about 1 to 4 μm, about 1 to 3 μm, about 2 to 5 μm, about 2 to 4 μm, and about 2 to 3 μm.

[0127] The surface coating layer 6 may contain additives such as the aforementioned lubricants, antiblocking agents, matting agents, flame retardants, antioxidants, tackifiers, and antistatic agents, at least on the surface and / or inside of the surface coating layer 6, as needed, depending on the functionality to be imparted to the surface of the surface coating layer 6. Examples of additives include fine particles with an average particle size of approximately 0.5 nm to 5 μm. The average particle size of the additive is the median size measured with a laser diffraction / scattering particle size distribution analyzer.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] The lubricant present on the surface of the surface coating layer 6 may be a lubricant exuded from the resin constituting the base layer 1, or a lubricant applied to the surface of the base layer 1. The lubricant present on the surface of the surface coating layer 6 may be a lubricant that was present on the surface of the heat-fusible resin layer 4 and has been transferred to the surface of the surface coating layer 6 when the electrical storage device packaging material is in a wound state around a core or the like.

[0132] 3. Manufacturing method for exterior materials for power storage devices The method for producing an electrical storage device packaging material is not particularly limited as long as it can produce a laminate in which the layers included in the electrical storage device packaging material of the present invention are laminated, and examples include methods that include a step of laminating at least a substrate layer 1, a barrier layer 3, and a heat-sealable resin layer 4 in this order. That is, the method for producing an electrical storage device packaging material of the present disclosure includes a step of laminating at least a substrate layer, a barrier layer, and a heat-sealable resin layer in this order to produce a laminate, in which the thickness of the substrate layer is 18 μm or more and 22 μm or less, the thickness of the barrier layer is 27 μm or more and 38 μm or less, and the thickness of the laminate is 100 μm or less.

[0133] An example of a method for producing an exterior packaging material for an electricity storage device of the present invention is as follows. First, a laminate (hereinafter, sometimes referred to as "laminate A") is formed in which a base layer 1, an adhesive layer 2, and a barrier layer 3 are laminated in this order. Specifically, laminate A can be formed by a dry lamination method in which an adhesive used to form adhesive layer 2 is applied to base layer 1 or to barrier layer 3 whose surface has been chemically treated as necessary, by a coating method such as gravure coating or roll coating, and then dried, and then the barrier layer 3 or base layer 1 is laminated thereon, and the adhesive layer 2 is cured.

[0134] Next, a heat-sealable resin layer 4 is laminated on the barrier layer 3 of the laminate A. When the heat-sealable resin layer 4 is laminated directly on the barrier layer 3, the heat-sealable resin layer 4 may be laminated on the barrier layer 3 of the laminate A by a method such as thermal lamination or extrusion lamination. When an adhesive layer 5 is provided between the barrier layer 3 and the heat-sealable resin layer 4, for example, (1) a method of laminating the adhesive layer 5 and the heat-sealable resin layer 4 by extruding them onto the barrier layer 3 of the laminate A (co-extrusion lamination, tandem lamination), (2) a method of separately forming a laminate in which the adhesive layer 5 and the heat-sealable resin layer 4 are laminated, and laminating this on the barrier layer 3 of the laminate A by a thermal lamination, or a method of forming a laminate in which the adhesive layer 5 is laminated on the barrier layer 3 of the laminate A, and laminating this on the heat-sealable resin layer 4 by a thermal lamination. (3) a method (sandwich lamination method) in which a molten adhesive layer 5 is poured between the barrier layer 3 of the laminate A and a heat-sealable resin layer 4 previously formed into a sheet, and the laminate A and the heat-sealable resin layer 4 are bonded together via the adhesive layer 5; (4) a method in which an adhesive for forming the adhesive layer 5 is solution-coated on the barrier layer 3 of the laminate A, followed by drying or baking, and then the heat-sealable resin layer 4 previously formed into a sheet is laminated on the adhesive layer 5.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 4. Applications of exterior materials for energy storage devices The exterior packaging material for an electricity storage device according to the present disclosure is used in a package for hermetically housing an electricity storage device element such as a positive electrode, a negative electrode, an electrolyte, etc. That is, an electricity storage device can be formed by housing an electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte in a package formed from the exterior packaging material for an electricity storage device according to the present disclosure.

[0139] Specifically, an electricity storage device using the electricity storage device packaging material is provided by covering an electricity storage device element having at least a positive electrode, a negative electrode, and an electrolyte with the electricity storage device packaging material of the present disclosure in a state in which metal terminals connected to each of the positive electrode and the negative electrode protrude outward, so that a flange portion (a region where the heat-sealable resin layers contact each other) can be formed around the periphery of the electricity storage device element, and heat-sealing the heat-sealable resin layers of the flange portion to form a hermetic seal. Note that when an electricity storage device element is housed in a package formed from the electricity storage device packaging material of the present disclosure, the package is formed so that the heat-sealable resin portion of the electricity storage device packaging material of the present disclosure faces inside (the surface in contact with the electricity storage device element). A package may be formed by overlapping two electrical storage device exterior packaging materials with the heat-sealable resin layers facing each other and heat-sealing the peripheral portions of the overlapped electrical storage device exterior packaging materials. Alternatively, as shown in the example of FIG. 5, one electrical storage device exterior packaging material may be folded back and overlapped, and the peripheral portions may be heat-sealed to form a package. When folding back and overlapping, as shown in the example of FIG. 5, the sides other than the folded side may be heat-sealed to form a package with a three-sided seal, or the material may be folded back to form a flange and sealed on all four sides. Furthermore, a recess for accommodating an electrical storage device element may be formed in the electrical storage device exterior packaging material by deep drawing or bulging molding. As shown in the example of FIG. 5, one electrical storage device exterior packaging material may have a recess and the other electrical storage device exterior material may not have a recess, or the other electrical storage device exterior material may also have a recess.

[0140] The exterior material for an electricity storage device according to the present disclosure can be suitably used in electricity storage devices such as batteries (including condensers, capacitors, etc.). The exterior material for an electricity storage device according to the present disclosure may be used in either primary or secondary batteries, but is preferably used in secondary batteries. The type of secondary battery to which the exterior material for an electricity storage device according to the present disclosure is applied is not particularly limited, and examples include lithium ion batteries, lithium ion polymer batteries, all-solid-state 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, lithium ion batteries and lithium ion polymer batteries are suitable applications for the exterior material for an electricity storage device according to the present disclosure. [Example]

[0141] The present disclosure will be described in detail below with reference to examples and comparative examples, but the present disclosure is not limited to the examples.

[0142] <Manufacturing of exterior materials for energy storage devices> Examples 1-8 and Comparative Examples 1-8 Each electrical storage device packaging material was manufactured by the following procedure, using the materials and thicknesses of each layer listed in Table 1. A biaxially oriented nylon film (Ny, thickness listed in Table 1) was prepared as a base layer, and aluminum foil (JIS H4160:1994 A8021H-O, thickness listed in Table 1) was prepared as a barrier layer with acid-resistant coatings formed on both sides. The biaxially oriented nylon film used in Example 1-8 had a crystallinity of 1.72, and the biaxially oriented nylon film used in Comparative Example 1-4 had a crystallinity of 1.68. The crystallinity was measured using a Nicolet iS10 (manufactured by Thermo Fisher Scientific) by the method described above, with the biaxially oriented nylon film laminated on the electrical storage device packaging material as the measurement target. Two types of aluminum foil obtained from different sources were used. The base layer and barrier layer were laminated by dry lamination. Specifically, a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one side of an aluminum foil with an acid-resistant coating formed on both sides, forming an adhesive layer (3 μm thick after curing) on the aluminum foil. Next, the adhesive layer on the aluminum foil and a biaxially oriented nylon film were laminated, and then aging treatment was performed to produce a laminate of base layer / adhesive layer / barrier layer. In Examples 2 and 6, a two-component curing urethane adhesive (a black pigment, a polyol compound, and an aromatic isocyanate compound) containing a black pigment was used instead of the two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate compound) used to bond the base layer and the barrier layer.

[0143] Next, in Examples 1, 3, 5, and 7 and Comparative Examples 1 to 8, maleic anhydride-modified polypropylene (PPa, thickness shown in Table 1) as an adhesive layer and polypropylene (PP, thickness shown in Table 1) as a heat-sealable resin layer were co-extruded onto the barrier layer of the obtained laminate, thereby laminating an adhesive layer / heat-sealable resin layer on the barrier layer. Next, the obtained laminate was aged and heated to obtain an exterior packaging material for an electricity storage device (total thickness shown in Table 1) in which a biaxially oriented nylon film / adhesive layer / barrier layer / adhesive layer / heat-sealable resin layer were laminated in this order.

[0144] In Examples 2 and 6, a maleic anhydride-modified polypropylene (PPa, thickness listed in Table 1) as an adhesive layer and a polypropylene (PP, thickness listed in Table 1) as a heat-sealable resin layer were co-extruded onto the barrier layer of the resulting laminate, thereby laminating an adhesive layer / heat-sealable resin layer on the barrier layer. Furthermore, a resin composition (thickness after curing: 3 μm) containing silica as a filler additive with an average particle size of 1.5 μm, erucic acid amide, and a styrene-based resin with an average particle size of 2.5 μm was gravure-coated onto the surface of the biaxially oriented nylon film of the resulting laminate, forming a matte surface coating layer. This resulted in an exterior packaging material for a power storage device (total thickness listed in Table 1) in which the surface coating layer / biaxially oriented nylon film / adhesive layer / barrier layer / adhesive layer / heat-sealable resin layer were laminated in this order. The average particle size of the silica was the median diameter measured using a laser diffraction / scattering particle size distribution analyzer (Horiba, Ltd., "LA-950").

[0145] In Examples 4 and 8, a two-component curing adhesive (acid-modified polypropylene and an epoxy compound) was applied onto the barrier layer of a laminate of base layer / adhesive layer / barrier layer, and an adhesive layer (3 μm thick after curing) was formed on aluminum foil. Furthermore, an unstretched polypropylene film (CPP, thickness listed in Table 1) was laminated onto the adhesive layer by dry lamination. The resulting laminate was then aged and heated to obtain an exterior packaging material for an electricity storage device (total thickness listed in Table 1) in which a biaxially oriented nylon film / adhesive layer / barrier layer / adhesive layer / thermal adhesive resin layer were laminated in this order.

[0146] Erucic acid amide was applied as a lubricant to the outer surface of the base material layer of each of the packaging materials for an electricity storage device in Examples 1, 3-5, 7, and 8 and Comparative Examples 1-8.

[0147] <Coefficient of dynamic friction on outer surface> The dynamic friction coefficient of the outer surface (surface on the substrate layer side) of the electrical storage device packaging materials obtained in the Examples and Comparative Examples was measured as follows. The friction test was performed using a method conforming to JIS K7125:1999, Section 8.1, Film-to-Film Measurement. First, each electrical storage device packaging material obtained above was cut into two samples measuring 80 mm in the TD direction and 200 mm in the MD direction. Next, the samples were stacked with their outer surfaces facing each other, and a sliding piece was placed on top of them. Rubber was attached to the bottom of the sliding piece, with a total mass of 200 g. The sample and the sliding piece were closely attached to prevent slippage. Next, the sliding piece was pulled at a speed of 100 mm / min, and the dynamic friction force (N) between the two samples was measured. The dynamic friction force was divided by the normal force of the sliding piece (1.96 N) to calculate the dynamic friction coefficient. The dynamic friction coefficient was calculated from the average value over the first 30 mm after the start of relative shear movement between the contact surfaces, ignoring the peak static friction force. The load cell was directly connected to the slider. The results were evaluated according to the following criteria. The results are shown in Table 1.

[0148] <Evaluation of curl due to molding> The resulting electrical storage device exterior material was cut into strips measuring 150 mm in the transverse direction (TD) × 90 mm in the machine direction (MD), which were used as test samples. A 31.6 mm × 54.5 mm rectangular male mold (the surface had a maximum height roughness (nominal Rz value) of 1.6 μm, a corner R of 2.0 mm, and a ridge R of 1.0 mm, as specified in Table 2 of the comparative surface roughness standard specimen in Appendix 1 of JIS B 0659-1:2002 (reference)) was placed between the male mold and a female mold (the surface had a maximum height roughness (nominal Rz value) of 1.6 μm, a corner R of 2.0 mm, and a ridge R of 1.0 mm, as specified in Table 2 of the comparative surface roughness standard specimen in Appendix 1 of JIS B 0659-1:2002 (reference)) with a clearance of 0.3 mm. The maximum height roughness (nominal Rz value) of the comparative surface roughness standard specimen, as specified in Table 2, was 3.2 μm. Using a mold with a corner radius of 2.0 mm and a ridge radius of 1.0 mm, the test sample was placed on a female mold with the heat-sealable resin layer facing the male mold. The test sample was then pressed with a pressure (surface pressure) of 0.25 MPa to a dimension of 31.6 mm (MD) × 54.5 mm (TD) and a molding depth of 6 mm, and cold-formed (single-stage drawing molding). Details of the molding position are shown in FIG. 6. As shown in FIG. 6, molding was performed at a position where the shortest distance d between the rectangular molding portion M and the end P of the exterior material 10 for an electricity storage device was 70.5 mm. The molding portion M indicates the position where a recess was formed by the mold. Next, the formed electrical storage device packaging material 10 was placed on a horizontal surface 20 as shown in FIG. 7, and the maximum distance t in the vertical direction y from the horizontal surface 20 to the end P was taken as the maximum height of the curled portion (the corner showing the maximum height among the four corners of the test sample). The smaller the value of the curl due to forming, the smaller the curl, and the more excellent the packaging material for an electrical storage device. The formed curl (mm) is the maximum value t rounded to one decimal place. The formed curl was evaluated according to the following criteria. The results are shown in Table 1. A+: The curl during molding is 0 mm or more and less than 15 mm. The curl during molding is small, and does not substantially reduce productivity. A: The curl formed is 15 mm or more and less than 25 mm. The curl formed is somewhat large, but the decrease in productivity is small. B: The curl formed is 25 mm or more and less than 35 mm. The curl formed is large, and productivity is greatly reduced. C: The curl formed is 35 mm or more. The curl formed is very large, and the decrease in productivity is very large.

[0149] [Mechanical strength evaluation] The mechanical strength of the packaging material for an electricity storage device was evaluated by the following puncture strength measurement and four-fold test. The results are shown in Table 1.

[0150] <Puncture Strength> The puncture strength of the laminate constituting the exterior material for an electrical storage device from the outer surface side (substrate layer side or surface coating layer side) was measured using an Imada ZP-50N force gauge and an Imada MX2-500N measurement stand in accordance with JIS Z1707:1997. Specifically, in a measurement environment of 23±2°C and 50±5% relative humidity, a test specimen was fixed using a 115mm diameter base with a 15mm diameter opening in the center and a pressure plate. A semicircular needle with a 1.0mm diameter and a 0.5mm tip radius was pierced at a rate of 50±5mm per minute, and the maximum stress until the needle penetrated was measured. Ten test specimens were measured, and the average value was calculated. Note that if there were not enough test specimens to measure 10, the remaining number was measured and the average value was calculated. The evaluation criteria are as follows: A+: The puncture strength is 23N or more. A: The puncture strength is 19N or more but less than 23N. B: The puncture strength is 18N or more but less than 19N. C: The puncture strength is less than 18N.

[0151] <Four-fold test> The resulting electrical storage device exterior material was cut into strips measuring 150 mm in the transverse direction (TD) and 90 mm in the machine direction (MD), which served as test samples. The test samples were folded into quarters 10 times, and the number of times until a pinhole formed in the center was measured. The quartering process consisted of folding the test sample in half at the center in the TD direction, with the short sides (sides in the MD) of the test sample overlapping, so that the heat-sealable resin layers overlapped at the center in the TD direction. The test sample was then folded in half again at the center in the MD direction, with the TD sides overlapping at the center, resulting in a quartering at the center of the test sample. This operation counted as one quartering process. The test sample was then unfolded, and the same quartering and unfolding processes were repeated to conduct the test. Five test samples were used for each test, and the average number of times until a pinhole formed in the center was calculated. If there were not enough test samples to measure five, the number of measurements that could be made was measured, and the average was calculated. The evaluation criteria were as follows: A+: It takes 7 or more times to form a pinhole in the center. A: The number of times until a pinhole is formed in the center is between 5 and 6. B: The number of times until a pinhole is formed in the center is 2 or more and 4 or less. C: One cycle until a pinhole is formed in the center.

[0152] [Table 1]

[0153] In Table 1, "ONy" represents biaxially oriented nylon film, "urethane" represents an adhesive layer formed using a two-component curing urethane adhesive using the dry lamination method, and "ALM A" and "ALM B" represent aluminum foils.

[0154] As shown in Table 1, the electrical storage device packaging material of Example 1-8 is composed of a laminate having at least a base layer, a barrier layer, and a heat-sealable resin layer in this order, with the base layer having a thickness of 18 μm or more and 22 μm or less, the barrier layer having a thickness of 27 μm or more and 38 μm or less, and the laminate having a thickness of 100 μm or less. It can be seen that the electrical storage device packaging material of Example 1-8 is suppressed from curling during molding despite its thin thickness of 100 μm or less, and further has high mechanical strength.

[0155] As described above, the present disclosure provides the following aspects of the invention. Item 1. The laminate is composed of at least a base layer, a barrier layer, and a heat-sealable resin layer in this order, The thickness of the base layer is 18 μm or more and 22 μm or less, the thickness of the barrier layer is 27 μm or more and 38 μm or less; The laminate has a thickness of 100 μm or less. Item 2. An adhesive layer is provided between the barrier layer and the thermal adhesive resin layer, The thickness of the adhesive layer is 12 μm or more and 17 μm or less, Item 2. The packaging material for an electricity storage device according to Item 1, wherein the thickness of the heat-sealable resin layer is 8 μm or more and 17 μm or less. Item 3. An adhesive layer is provided between the barrier layer and the heat-sealable resin layer, The thickness of the adhesive layer is 1 μm or more and 5 μm or less, Item 2. The packaging material for an electricity storage device according to Item 1, wherein the thickness of the heat-sealable resin layer is 22 μm or more and 33 μm or less. Item 4. The packaging material for an electricity storage device according to any one of Items 1 to 3, further comprising a surface coating layer on the side of the base material layer opposite to the barrier layer side. Item 5. An electricity storage device, in which an electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed from the exterior packaging material for an electricity storage device according to any one of Items 1 to 4. Item 6. The method includes a step of laminating at least a base layer, a barrier layer, and a heat-sealable resin layer in this order to obtain a laminate, The thickness of the base layer is 18 μm or more and 22 μm or less, the thickness of the barrier layer is 27 μm or more and 38 μm or less; A method for producing an exterior material for an electricity storage device, wherein the thickness of the laminate is 100 μm or less. [Explanation of symbols]

[0156] 1 Base material layer 2 Adhesive layer 3 Barrier layer 4 Heat-fusible resin layer 5 Adhesive layer 6 Surface coating layer 10. Exterior materials for energy storage devices

Claims

1. The laminate is composed of at least a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-sealable resin layer in this order, the substrate layer includes a stretched polyamide film, The thickness of the base layer is 18 μm or more and 22 μm or less, the adhesive layer is formed of a polyurethane adhesive; The thickness of the adhesive layer is 1 μm or more and 10 μm or less, the barrier layer comprises an aluminum alloy foil; the thickness of the barrier layer is 27 μm or more and 38 μm or less; the adhesive layer comprises a polyolefin; the heat-sealable resin layer contains polyolefin, a total thickness of the layers located closer to the thermal adhesive resin layer than the barrier layer is 20 μm or more and 40 μm or less; The laminate has a thickness of 100 μm or less.

2. The thickness of the adhesive layer is 12 μm or more and 17 μm or less, The packaging material for an electricity storage device according to claim 1 , wherein the thermally adhesive resin layer has a thickness of 8 μm or more and 17 μm or less.

3. The thickness of the adhesive layer is 1 μm or more and 5 μm or less, 2 . The packaging material for an electricity storage device according to claim 1 , wherein the thermally adhesive resin layer has a thickness of 22 μm or more and 33 μm or less.

4. The packaging material for an electricity storage device according to any one of claims 1 to 3, further comprising a surface coating layer on the opposite side of the base material layer from the barrier layer side.

5. The packaging material for an electricity storage device according to any one of claims 1 to 4, wherein two or more types of lubricants are present on at least one of the surface and the interior of the base material layer.

6. The exterior material for an electricity storage device according to any one of claims 1 to 5, wherein at least two selected from the group consisting of saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylol amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides are present on at least one of the surface and the interior of the base material layer.

7. a lubricant is present on the surface of the substrate layer; The amount of the lubricant present is 3 mg / m 2 The electrical storage device packaging material according to any one of claims 1 to 6.

8. a lubricant is present on the surface of the heat-sealable resin layer; The amount of the lubricant present is 10 mg / m 2 The packaging material for an electricity storage device according to any one of claims 1 to 7.

9. The packaging material for an electricity storage device according to any one of claims 1 to 8, wherein the heat-sealable resin layer is made of a resin containing a polyolefin skeleton.

10. The heat-sealable resin layer comprises at least one selected from the group consisting of polyolefins, cyclic polyolefins, acid-modified polyolefins, and acid-modified cyclic polyolefins. An outer casing material for an electricity storage device according to any one of claims 1 to 9.

11. The packaging material for an electricity storage device according to any one of claims 1 to 10, wherein the heat-sealable resin layer is formed from a blend polymer in which two or more types of resins are combined.

12. The packaging material for an electricity storage device according to any one of claims 1 to 11, wherein the heat-sealable resin layer is formed of two or more layers made of the same or different resins.

13. The packaging material for an electricity storage device according to any one of claims 1 to 12, wherein two or more types of lubricants are present on at least one of the surface and the interior of the heat-sealable resin layer.

14. The electrical storage device packaging material according to any one of claims 1 to 13, wherein at least two selected from the group consisting of saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylol amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides are present on at least one of the surface and the interior of the heat-sealable resin layer.

15. An exterior material for an electricity storage device according to claim 1, wherein the adhesive layer is made of a resin containing a polyolefin skeleton.

16. An exterior material for an electrical storage device described in any one of claims 1 to 15, wherein the adhesive layer comprises at least one selected from the group consisting of polyolefins, cyclic polyolefins, acid-modified polyolefins, and acid-modified cyclic polyolefins.

17. An exterior material for an electricity storage device described in any one of claims 1 to 16, wherein the adhesive layer is formed from a blend polymer that combines two or more types of resins.

18. a surface coating layer on the opposite side of the substrate layer from the barrier layer side, The packaging material for an electricity storage device according to any one of claims 1 to 17, wherein a lubricant is present on at least one of the surface and the interior of the surface coating layer.

19. a surface coating layer on the opposite side of the substrate layer from the barrier layer side, The packaging material for an electricity storage device according to any one of claims 1 to 18, wherein two or more types of lubricants are present on at least one of the surface and the interior of the surface coating layer.

20. a surface coating layer on the opposite side of the substrate layer from the barrier layer side, The exterior material for a storage battery device according to any one of claims 1 to 19, wherein at least one selected from the group consisting of saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylol amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides is present on at least one of the surface and the interior of the surface coating layer.

21. An electricity storage device, wherein an electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed from the exterior packaging material for an electricity storage device according to any one of claims 1 to 20.

22. The method includes a step of laminating at least a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-sealable resin layer in this order to obtain a laminate, the substrate layer includes a stretched polyamide film, The thickness of the base layer is 18 μm or more and 22 μm or less, the adhesive layer is formed of a polyurethane adhesive; The thickness of the adhesive layer is 1 μm or more and 10 μm or less, the barrier layer comprises an aluminum alloy foil; the thickness of the barrier layer is 27 μm or more and 38 μm or less; the adhesive layer comprises a polyolefin; the heat-sealable resin layer contains polyolefin, a total thickness of the layers located closer to the thermal adhesive resin layer than the barrier layer is 20 μm or more and 40 μm or less; The method for producing an exterior material for an electricity storage device, wherein the laminate has a thickness of 100 μm or less.

23. A method for manufacturing an exterior material for an electricity storage device as described in claim 22, wherein the adhesive layer and the heat-sealable resin layer are formed by a co-extrusion lamination method, a tandem lamination method, a thermal lamination method, a sandwich lamination method, or a method in which an adhesive for forming the adhesive layer is solution-coated onto the barrier layer, and the heat-sealable resin layer, which has been previously formed into a sheet, is laminated onto the adhesive layer.

24. The method for producing an exterior packaging material for an electricity storage device according to claim 22 or 23, wherein the heat-sealable resin layer is formed of two or more layers made of the same or different resins.

Images