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

Abstract

This exterior member for a power storage device is composed of a laminate including at least a base material layer, a barrier layer, and a heat-fusible resin layer in order from the outside. The barrier layer contains 50 mass % or more of a recycled material of an aluminum alloy. The recycled material of the aluminum alloy is a recycled material of a 1000-series aluminum alloy, a recycled material of a 3000-series aluminum alloy, or a recycled material of a 5000-series aluminum alloy.

Description

Outer member for power storage device, method for manufacturing outer member for power storage device, power storage device, and method for manufacturing power storage device

[0001] The present invention relates to an outer member for a power storage device, a method for manufacturing the outer member for a power storage device, a power storage device including the outer member for a power storage device, and a method for manufacturing the power storage device.

[0002] Patent Document 1 discloses a secondary battery as an example of a power storage device. In this secondary battery, an electrode body is sealed in a bag body formed of a laminate film. The laminate film includes a water vapor impermeable layer as an example of a barrier layer for suppressing the intrusion of water vapor into the bag body. The water vapor impermeable layer is formed of, for example, a metal foil of an aluminum alloy.

[0003] Patent No. 4509242

[0004] From the perspective of global environmental protection, it is preferable that the power storage device be manufactured in an energy-saving manner. For this reason, it is conceivable to use recycled materials as the aluminum alloy contained in the barrier layer. On the other hand, when the power storage device contains an electrolytic solution, if the negative electrode of the power storage device and the aluminum alloy contained in the barrier layer are short-circuited and electricity flows through the electrolytic solution, the aluminum alloy may corrode and problems may occur. Also, when the power storage device is a all-solid-state battery, if the negative electrode of the power storage device and the aluminum alloy contained in the barrier layer are short-circuited and electricity flows through the solid electrolyte, the aluminum alloy may corrode and problems may occur. Therefore, when using a recycled material as the aluminum alloy contained in the barrier layer, it is preferable to use a recycled material of an aluminum alloy with high corrosion resistance.

[0005] An object of the present invention is to provide an outer member for a power storage device that reduces environmental impact and has high corrosion resistance, a method for manufacturing the outer member for a power storage device, a power storage device including the outer member for a power storage device, and a method for manufacturing the power storage device.

[0006] An exterior component for an energy storage device according to a first aspect of the present invention is composed of a laminate comprising, in order from the outside, at least a base material layer, a barrier layer, and a heat-fusible resin layer, wherein the barrier layer contains 50% by mass or more of recycled aluminum alloy, and the recycled aluminum alloy is recycled 1000 series aluminum alloy, recycled 3000 series aluminum alloy, or recycled 5000 series aluminum alloy.

[0007] An exterior member for an energy storage device according to a second aspect of the present invention is an exterior member for an energy storage device according to a first aspect, wherein the recycled aluminum alloy contained in the barrier layer is less than 100% by mass, and when the recycled aluminum alloy is recycled 1000 series aluminum alloy, the remaining aluminum alloy contained in the barrier layer is virgin 3000 series aluminum alloy or virgin 5000 series aluminum alloy, when the recycled aluminum alloy is recycled 3000 series aluminum alloy, the remaining aluminum alloy contained in the barrier layer is virgin 1000 series aluminum alloy, and when the recycled aluminum alloy is recycled 5000 series aluminum alloy, the remaining aluminum alloy contained in the barrier layer is virgin 1000 series aluminum alloy.

[0008] An exterior component for an energy storage device according to a third aspect of the present invention is composed of a laminate comprising, in order from the outside, at least a base layer, a barrier layer, and a heat-fusible resin layer, wherein the barrier layer contains 50% by mass or more of recycled aluminum alloy, and the recycled aluminum alloy has a composition of Si: 0.25% by mass or less, Fe: 0.40% by mass or less, Cu: 0.20% by mass or less, Mn: 0.05% by mass or less, Mg: 0.10% by mass or less, and unavoidable impurities of 0.15% by mass or less.

[0009] An exterior member according to a fourth aspect of the present invention is composed of a laminate comprising, in order from the outside, at least a base layer, a barrier layer, and a heat-fusible resin layer, wherein the barrier layer contains 50% by mass or more of recycled aluminum alloy, and the recycled aluminum alloy satisfies the following composition: Si: 0.60% by mass or less, Fe: 0.80% by mass or less, Cu: 0.30% by mass or less, Mn: 0.30% by mass or more, 1.50% by mass or less, Mg: 1.30% by mass or less, Cr: 0.20% by mass or less, Zn: 0.40% by mass or less, and unavoidable impurities of 0.15% by mass or less.

[0010] An exterior component for an energy storage device according to a fifth aspect of the present invention is composed of a laminate comprising, in order from the outside, at least a base layer, a barrier layer, and a heat-fusible resin layer, wherein the barrier layer contains 50% by mass or more of recycled aluminum alloy, and the recycled aluminum alloy satisfies the following composition: Si: 0.40% by mass or less, Fe: 0.70% by mass or less, Cu: 0.20% by mass or less, Mn: 1.00% by mass or less, Mg: 0.20% by mass or more, 5.50% by mass or less, Cr: 0.50% by mass or less, Zn: 0.25% by mass or less, and unavoidable impurities of 0.15% by mass or less.

[0011] A method for manufacturing an exterior member for an energy storage device according to the sixth aspect of the present invention is a method for manufacturing an exterior member for an energy storage device according to any one of the first to fifth aspects, comprising the step of manufacturing the laminate, wherein the barrier layer contains 50% by mass or more of recycled aluminum alloy material.

[0012] A seventh aspect of the present invention relates to an energy storage device comprising an exterior member for an energy storage device and an electrode body packaged by the exterior member for an energy storage device, wherein the exterior member for an energy storage device is composed of a laminate comprising, in order from the outside, at least a base layer, a barrier layer, and a heat-fusible resin layer, the barrier layer contains 50% by mass or more of recycled aluminum alloy, and the aluminum alloy contained in the barrier layer is recycled 1000 series aluminum alloy, recycled 3000 series aluminum alloy, or recycled 5000 series aluminum alloy.

[0013] An energy storage device according to the eighth aspect of the present invention is an energy storage device according to the seventh aspect, wherein the recycled aluminum alloy material contained in the barrier layer is less than 100% by mass, and when the recycled aluminum alloy material is recycled 1000 series aluminum alloy, the remaining aluminum alloy material contained in the barrier layer is virgin 3000 series aluminum alloy or virgin 5000 series aluminum alloy, when the recycled aluminum alloy material is recycled 3000 series aluminum alloy, the remaining aluminum alloy material contained in the barrier layer is virgin 1000 series aluminum alloy, and when the recycled aluminum alloy material is recycled 5000 series aluminum alloy, the remaining aluminum alloy material contained in the barrier layer is virgin 1000 series aluminum alloy.

[0014] A ninth aspect of the present invention relates to an energy storage device comprising an outer casing member for an energy storage device and an electrode body packaged by the outer casing member for an energy storage device, wherein the outer casing member for an energy storage device is composed of a laminate comprising, in order from the outside, at least a base layer, a barrier layer, and a heat-fusible resin layer, the barrier layer contains 50% by mass or more of recycled aluminum alloy material, and the recycled aluminum alloy material satisfies a composition of Si: 0.25% by mass or less, Fe: 0.40% by mass or less, Cu: 0.20% by mass or less, Mn: 0.05% by mass or less, Mg: 0.10% by mass or less, and unavoidable impurities of 0.15% by mass or less.

[0015] A power storage device according to a tenth aspect of the present invention includes an outer casing member for a power storage device and an electrode body packaged by the outer casing member for a power storage device, wherein the outer casing member for a power storage device is composed of a laminate comprising, in order from the outside, at least a base layer, a barrier layer, and a heat-fusible resin layer, the barrier layer contains 50% by mass or more of recycled aluminum alloy material, and the recycled aluminum alloy material satisfies the composition of Si: 0.60% by mass or less, Fe: 0.80% by mass or less, Cu: 0.30% by mass or less, Mn: 0.30% by mass or more, 1.50% by mass or less, Mg: 1.30% by mass or less, Cr: 0.20% by mass or less, Zn: 0.40% by mass or less, and unavoidable impurities of 0.15% by mass or less.

[0016] An energy storage device according to an eleventh aspect of the present invention includes an outer casing member for an energy storage device and an electrode body packaged by the outer casing member for an energy storage device, wherein the outer casing member for an energy storage device is composed of a laminate comprising, in order from the outside, at least a base layer, a barrier layer, and a heat-fusible resin layer, the barrier layer contains 50% by mass or more of recycled aluminum alloy material, and the recycled aluminum alloy material satisfies the composition of Si: 0.40% by mass or less, Fe: 0.70% by mass or less, Cu: 0.20% by mass or less, Mn: 1.00% by mass or less, Mg: 0.20% by mass or more, 5.50% by mass or less, Cr: 0.50% by mass or less, Zn: 0.25% by mass or less, and unavoidable impurities of 0.15% by mass or less.

[0017] A power storage device according to the twelfth aspect of the present invention is a power storage device according to any one of the seventh to eleventh aspects, and includes a first sealing portion which is sealed by joining opposing surfaces of the outer casing member for the power storage device together while the electrode body is enclosed by the outer casing member for the power storage device.

[0018] A power storage device according to the thirteenth aspect of the present invention is a power storage device according to any one of the seventh to twelfth aspects, further comprising: a lid that seals the electrode body together with the exterior member for the power storage device; and a second sealing portion to which the lid and the exterior member for the power storage device are joined.

[0019] A fourteenth aspect of the present invention relates to a power storage device relating to any one of the seventh to thirteenth aspects, wherein the exterior member for the power storage device includes a first exterior member and a second exterior member, and at least one of the first exterior member and the second exterior member has a recess formed therein for housing the electrode body.

[0020] A power storage device according to the fifteenth aspect of the present invention is a method for manufacturing a power storage device according to any one of the seventh to fourteenth aspects, comprising the step of manufacturing an exterior member for the power storage device composed of the laminate, wherein the barrier layer contains 50% by mass or more of recycled aluminum alloy material.

[0021] The exterior component for energy storage devices, the method for manufacturing the exterior component for energy storage devices, the energy storage device, and the method for manufacturing the energy storage device according to the present invention contribute to reducing environmental impact and have high corrosion resistance.

[0022] This is a schematic perspective view showing a power storage device according to Embodiment 1. This is a cross-sectional view showing an example of the layer configuration of the exterior member in Figure 1A. This is a schematic plan view showing a power storage device. This is a schematic side view showing a power storage device. This is a diagram showing the state in which the exterior member is wrapped around the electrode body during the manufacturing process of the power storage device according to Embodiment 1, viewed from the side. This is a diagram showing the state in which the exterior member is wrapped around the electrode body during the manufacturing process of the power storage device according to Embodiment 1, viewed from below. This is a diagram showing a part of the VI-VI cross section of Figure 2. This is a diagram for explaining the method of forming the second sealing part. This is a flowchart showing an example of the manufacturing procedure for a power storage device according to Embodiment 1. This is a schematic plan view showing a power storage device according to Embodiment 2. This is a schematic side view showing a power storage device. This is a schematic perspective view showing a lid. This is a diagram showing a first example in which the lid and electrode terminals are integrally formed. This is a diagram showing a second example in which the lid and electrode terminals are integrally formed. This is a flowchart showing an example of the manufacturing procedure for a power storage device according to Embodiment 2. This is a flowchart showing another example of the manufacturing procedure for a power storage device according to Embodiment 2. This is a diagram showing the state in which the outer casing member is wrapped around the electrode body in Embodiment 3, viewed from the side. This is a diagram showing the state in which the outer casing member is wrapped around the electrode body and the lid is attached to the outer casing member in Embodiment 3, viewed from below. This is a flowchart showing an example of the manufacturing procedure for an energy storage device according to Embodiment 3. This is a schematic plan view showing an energy storage device according to Embodiment 4. This is a schematic side view showing an energy storage device according to Embodiment 4. This is a diagram showing the state in which the outer casing member is wrapped around the electrode body in a modified example, viewed from the side. This is a schematic perspective view showing an energy storage device of a modified example. This is a schematic perspective view showing a lid and electrode terminals attached to the lid in a modified example. This is a diagram showing the insertion step in the manufacturing method of an energy storage device of a modified example. This is a schematic perspective view showing a lid and electrode terminals attached to the lid in a modified example. This is a schematic perspective view showing an energy storage device with the lid of Figure 23 attached. This is a schematic front view showing a lid of another modified example. This is a schematic front view showing a lid of yet another modified example. This is a schematic plan view showing an energy storage device of another modified example. This is a cross-sectional view of an energy storage device of yet another modified example.This figure shows an example of the manufacturing process for another modified version of the energy storage device shown in Figure 30A. This is a perspective view of the energy storage device manufactured through the manufacturing process shown in Figure 30B. This is a perspective view of yet another modified version of the energy storage device shown in Figure 30A. This figure shows a side view of the state in which the outer casing material is wrapped around the electrode body during the manufacturing process of another modified version of the energy storage device. This is an enlarged view of the X portion of Figure 31. This is a cross-sectional view of the modified energy storage device. This is a cross-sectional view of the modified energy storage device.

[0023] Embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated. In this embodiment, the numerical range indicated by "~" means "greater than or equal to" and "less than or equal to". For example, the notation 2 to 15 mm means 2 mm or more and 15 mm or less. In the numerical ranges described in steps in this embodiment, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in steps. Alternatively, the upper and lower limits, upper and lower limits, or lower limits described separately may be combined to form a numerical range.

[0024] [1. Embodiment 1] <1-1. Configuration of the Energy Storage Device> Figure 1A is a schematic perspective view showing an energy storage device 10 according to this Embodiment 1. Figure 2 is a schematic plan view showing the energy storage device 10. Figure 3 is a schematic side view showing the energy storage device 10. In Figures 2 and 3, the direction of arrow UD indicates the thickness direction of the energy storage device 10, and the direction of arrow LR indicates the width direction of the energy storage device 10. Also, the direction of arrow FB indicates the depth direction of the energy storage device 10. The directions indicated by arrows UDLRFB are common to all subsequent figures.

[0025] Referring to Figures 1A, 1B, 2, and 3, the energy storage device 10 includes an electrode body 200, an outer casing 100, and a plurality (two) of electrode terminals 300. The electrode body 200 includes electrodes (positive and negative electrodes) and separators that constitute an energy storage component such as a lithium-ion battery, capacitor, or all-solid-state battery. The shape of the electrode body 200 is approximately a rectangular parallelepiped. Note that "approximately a rectangular parallelepiped" includes not only a perfect rectangular parallelepiped but also a three-dimensional object that can be considered a rectangular parallelepiped by, for example, modifying the shape of a part of its outer surface.

[0026] The electrode terminal 300 is a metal terminal used for power input and output in the electrode body 200. One end of the electrode terminal 300 is electrically connected to an electrode (positive or negative electrode) included in the electrode body 200, and the other end protrudes outward from the edge of the outer casing 100.

[0027] The metal material that constitutes the electrode terminal 300 is, for example, aluminum, nickel, copper, etc. For example, if the electrode body 200 is a lithium-ion battery, the electrode terminal 300 connected to the positive electrode is usually made of aluminum, etc., and the electrode terminal 300 connected to the negative electrode is usually made of copper, nickel, etc.

[0028] The outer casing 100 is made of a film-like outer casing member 101 for energy storage devices (hereinafter referred to as "outer casing member 101") as shown in Figure 1B, and seals the electrode body 200. In the energy storage device 10 of this embodiment, the outer casing 100 is formed by wrapping the outer casing member 101 around the electrode body 200 and sealing the open portion.

[0029] The outer casing 100 seals the electrode body 200 by wrapping the outer casing member 101 around the electrode body 200, so the electrode body 200 can be easily sealed regardless of the thickness of the electrode body 200. In order to reduce the dead space between the electrode body 200 and the outer casing member 101 in order to improve the volumetric energy density of the energy storage device 10, it is preferable that the outer casing member 101 is wrapped so as to be in contact with the outer surface of the electrode body 200. Furthermore, in all-solid-state batteries, it is necessary to eliminate the space between the electrode body 200 and the outer casing member 101 from the viewpoint that high pressure must be applied uniformly from the outside of the battery in order to achieve battery performance, so it is preferable that the outer casing member 101 is wrapped so as to be in contact with the outer surface of the electrode body 200. Alternatively, the outer casing 100 may be constructed by forming a housing portion (recess) in the outer casing member 101 through cold forming and housing the electrode body 200 in the housing portion.

[0030] Figure 1B is a cross-sectional view showing an example of the layer structure of the exterior member 101. The exterior member 101 is, for example, a laminate 101Z (laminate film) having, in order from the outside, at least a base layer 101A, a barrier layer 101B, and a heat-fusible resin layer 101C.

[0031] The exterior member 101 may be composed of a laminate comprising at least a barrier layer 101B and a heat-fusible resin layer 101C in that order. In this laminate, the base layer 101A is a layer provided as needed, with the side of the barrier layer 101B opposite to the heat-fusible resin layer 101C being the outermost layer, and the heat-fusible resin layer 101C being the innermost layer.

[0032] The overall thickness of the exterior member 101 can be arbitrarily selected. From the viewpoint of strength, the thickness of the exterior member 101 is preferably 50 μm or more. From the viewpoint of moldability or conformability, the thickness of the exterior member 101 is preferably 1200 μm or less. The thickness of the exterior member 101 is preferably within the range of 50 μm to 1200 μm.

[0033] The base layer 101A included in the exterior member 101 is a layer that imparts heat resistance to the exterior member 101 and suppresses the occurrence of pinholes that may occur during processing or distribution. The base layer 101A is composed of, for example, at least one stretched polyester resin layer and a stretched polyamide resin layer. For example, by including at least one stretched polyester resin layer and a stretched polyamide resin layer in the base layer 101A, the barrier layer 101B can be protected during processing of the exterior member 101, and the breakage of the exterior member 101 can be suppressed. Furthermore, from the viewpoint of increasing the tensile elongation of the exterior member 101, the stretched polyester resin layer is preferably a biaxially oriented polyester resin layer, and the stretched polyamide resin layer is preferably a biaxially oriented polyamide resin layer. Moreover, from the viewpoint of excellent puncture strength or impact strength, the stretched polyester resin layer is more preferably a biaxially oriented polyethylene terephthalate (PET) film, and the stretched polyamide resin layer is more preferably a biaxially oriented nylon (ONy) film. The base layer 101A may be composed of both a stretched polyester resin layer and a stretched polyamide resin layer. The thickness of the base layer 101A is preferably, for example, 5 to 300 μm, and more preferably 5 to 150 μm, from the viewpoint of film strength.

[0034] In the exterior member 101, the barrier layer 101B is a layer that suppresses the penetration of moisture. In this embodiment, the barrier layer 101B of the exterior member 101 contains an aluminum alloy. From the viewpoint of reducing environmental impact, in other words, from the viewpoint of energy conservation, the barrier layer 101B contains 50% by mass or more of recycled aluminum alloy. Preferably, the barrier layer 101B contains 80% by mass or more of recycled aluminum alloy, more preferably 90% by mass or more, and even more preferably 95% by mass or more. The aluminum alloy contained in the barrier layer 101B may all be recycled aluminum alloy. Preferably, the virgin aluminum alloy contained in the barrier layer 101B is less than 20% by mass. If the recycled aluminum alloy contained in the barrier layer 101B is less than 100% by mass, it is preferable that the remaining aluminum alloy contained in the barrier layer 101B is virgin aluminum alloy. If the recycled aluminum alloy contained in the barrier layer 101B is less than 100% by mass, the remaining aluminum alloy contained in the barrier layer 101B may include at least one of any virgin aluminum alloy and any recycled aluminum alloy, to the extent that the corrosion resistance of the exterior member 101 is not significantly reduced.

[0035] From the viewpoint of corrosion resistance to the electrolyte or all-solid electrolyte, the recycled aluminum alloy material contained in the barrier layer 101B is recycled 1000 series aluminum alloy, recycled 3000 series aluminum alloy, or recycled 5000 series aluminum alloy.

[0036] The inventors of this application have investigated the use of recycled materials as the aluminum alloy contained in the barrier layer 101B and have found that by using 1000 series aluminum alloy, 3000 series aluminum alloy, or 5000 series aluminum alloy, the exterior member 101 can be suitably wrapped around the electrode body 200, or a recess for accommodating the electrode body 200 can be formed by cold forming. Recycled 1000 series aluminum alloy, recycled 3000 series aluminum alloy, or recycled 5000 series aluminum alloy can be obtained by known methods.

[0037] Recycled 1000-series aluminum alloy refers to materials that have been recovered, isolated, and refined to make them reusable, such as waste materials from various products used in the market or from the manufacturing process of products containing aluminum alloy. Virgin material, on the other hand, refers to new metal materials refined from natural metal resources (raw materials) and is not recycled material. 1000-series aluminum alloy is often used, for example, in PS (Presensitized Plate) plates used in offset printing, or CTP (Computer To Plate) plates. The recycled 1000-series aluminum alloy contained in barrier layer 101B can be manufactured by rolling a slab obtained by remelting and casting recycled 1000-series aluminum alloy. For example, 1000-series aluminum alloy recovered from CTP plate printing can be remelted without refining. If the recycled 1000 series aluminum alloy contained in the barrier layer 101B is less than 100% by mass, the remaining aluminum alloy contained in the barrier layer 101B may include at least one of virgin aluminum alloy of any alloy number and recycled aluminum alloy of any alloy number, as long as the corrosion resistance of the exterior member 101 is not significantly reduced. For example, if the recycled 1000 series aluminum alloy contained in the barrier layer 101B is 95% by mass or more, even if the remaining aluminum alloy contained in the barrier layer 101B is recycled aluminum alloy of any alloy number and virgin aluminum alloy of any alloy number, a significant reduction in the corrosion resistance of the exterior member 101 is suppressed. If the recycled 1000 series aluminum alloy contained in the barrier layer 101B is less than 100% by mass, it is preferable that the remaining aluminum alloy contained in the barrier layer 101B is virgin aluminum alloy of the 1000 series.

[0038] As the 1000 series aluminum alloy, alloy numbers 1050, 1050A, 1060, 1065, 1070, 1070A, 1080, 1080A, 1085, 1090, 1098, or 1100 can be used. In 100% by mass of the 1000 series aluminum alloy, silicon (Si) is preferably 0.25% by mass or less, iron (Fe) is preferably 0.40% by mass or less, copper (Cu) is preferably 0.20% by mass or less, manganese (Mn) is preferably 0.05% by mass or less, magnesium (Mg) is preferably 0.10% by mass or less, and other unavoidable impurities are preferably 0.05% by mass or less and 0.15% by mass or less, respectively.

[0039] Recycled 3000 series aluminum alloy refers to materials that have been recovered, isolated, and refined from various products used in the market, as well as waste generated from the manufacturing process of products containing aluminum alloy, to make them reusable. Virgin material, on the other hand, refers to new metal materials refined from natural metal resources (raw materials), and is not recycled material. 3000 series aluminum alloy is widely used, for example, in beverage cans. The recycled 3000 series aluminum alloy contained in barrier layer 101B can be manufactured, for example, by crushing and sorting recycled 3000 series aluminum alloy contained in beverage cans, removing foreign matter, roasting to remove organic matter from the surface, remelting and casting, and then rolling the resulting slab. If the recycled 3000 series aluminum alloy contained in the barrier layer 101B is less than 100% by mass, the remaining aluminum alloy contained in the barrier layer 101B may include at least one of virgin aluminum alloy of any alloy number and recycled aluminum alloy of any alloy number, as long as the corrosion resistance of the exterior member 101 is not significantly reduced. For example, if the recycled 3000 series aluminum alloy contained in the barrier layer 101B is 95% by mass or more, even if the remaining aluminum alloy contained in the barrier layer 101B is recycled aluminum alloy of any alloy number and virgin aluminum alloy of any alloy number, a significant reduction in the corrosion resistance of the exterior member 101 is suppressed. If the recycled 3000 series aluminum alloy contained in the barrier layer 101B is less than 100% by mass, it is preferable that the remaining aluminum alloy contained in the barrier layer 101B is virgin aluminum alloy of the 3000 series.

[0040] As the 3000 series aluminum alloy, alloy numbers 3003, 3004, 3005, 3103, 3104, 3105, and 3203 can be used. In 100% by mass of the 3000 series aluminum alloy, silicon (Si) is preferably 0.60% by mass or less, iron (Fe) is preferably 0.80% by mass or less, copper (Cu) is preferably 0.30% by mass or less, manganese (Mn) is preferably 0.30% by mass or more and 1.50% by mass or less, magnesium (Mg) is preferably 1.30% by mass or less, chromium (Cr) is preferably 0.20% by mass or less, zinc (Zn) is preferably 0.40% by mass or less, and other unavoidable impurities are preferably 0.05% by mass or less and 0.15% by mass or less, respectively.

[0041] Recycled 5000 series aluminum alloy refers to materials that have been recovered, isolated, and refined from various products used in the market, as well as waste generated from the manufacturing process of products containing aluminum alloy, to make them reusable. Virgin material, on the other hand, refers to new metal materials refined from natural metal resources (raw materials), and is not recycled material. 5000 series aluminum alloy is widely used, for example, in railway vehicles. The recycled 5000 series aluminum alloy contained in barrier layer 101B can be manufactured by crushing and sorting recycled 5000 series aluminum alloy contained in railway vehicles, removing foreign matter, roasting to remove organic matter from the surface, remelting and casting, and then rolling the resulting slab. If the recycled 5000 series aluminum alloy contained in the barrier layer 101B is less than 100% by mass, the remaining aluminum alloy contained in the barrier layer 101B may include at least one of virgin aluminum alloy of any alloy number and recycled aluminum alloy of any alloy number, as long as the corrosion resistance of the exterior member 101 is not significantly reduced. For example, if the recycled 5000 series aluminum alloy contained in the barrier layer 101B is 95% by mass or more, even if the remaining aluminum alloy contained in the barrier layer 101B is recycled aluminum alloy of any alloy number and virgin aluminum alloy of any alloy number, a significant reduction in the corrosion resistance of the exterior member 101 is suppressed. If the recycled 5000 series aluminum alloy contained in the barrier layer 101B is less than 100% by mass, it is preferable that the remaining aluminum alloy contained in the barrier layer 101B is virgin aluminum alloy of the 5000 series.

[0042] For the 5000 series aluminum alloy, alloy numbers 5005, 5021, 5042, 5050, 5052, 5082, 5083, 5086, 5110A, 5154, 5182, 5254, 5454, 5456, and 5754 can be used. In 100% by mass of 5000 series aluminum alloy, silicon (Si) is preferably 0.40% by mass or less, iron (Fe) is preferably 0.70% by mass or less, copper (Cu) is preferably 0.20% by mass or less, manganese (Mn) is preferably 1.00% by mass or more, magnesium (Mg) is preferably 0.20% by mass or more and 5.50% by mass or less, chromium (Cr) is preferably 0.50% by mass or less, zinc (Zn) is preferably 0.25% by mass or less, and other unavoidable impurities are preferably 0.05% by mass or less and 0.15% by mass or less, respectively.

[0043] The composition of each component contained in the barrier layer 101B is measured as follows. The cross-section of the exterior member 101 is cut with a microtome, and the composition analysis of the barrier layer 101B in the cross-section direction is performed by the following method. In the case where the exterior member 101 is a single layer of the barrier layer 101B, the composition analysis is performed from the surface direction or the cross-section direction. The composition analysis uses a scanning electron microscope (SEM) and an energy-dispersive X-ray fluorescence spectrometry (EDX). For the SEM, SU8200 manufactured by Hitachi High-Tech or equivalent products can be used. For the EDX, X-MaxN Extreme manufactured by Oxford Instruments or equivalent products can be used. The composition analysis is performed by performing elemental analysis by energy-dispersive X-ray fluorescence spectrometry on the image observed by the scanning electron microscope. The elements to be detected are Si, Fe, Cu, Mn, Mg, Cr, Zn, Ti, Ga, V, Ni, B, and Zr. A calibration curve is created using a standard sample, and a repeated test (n = 10) is performed to conduct the composition analysis. The calibration curve of Mg takes into account the influence of absorption excitation between elements and performs coexisting element correction by the dj method. The calibration curves of Fe and Mn perform overlap correction by the lj method with Mn and Cr, respectively. Regarding the acceleration voltage, Si and Mg are 15 [kV], Fe, Cu, Mn, Cr, Zn, Ti, Ga, V, Ni, and Zr are 50 [kV], and B is 5 [kV]. The acceleration current is Auto [μA]. The atmosphere is vacuum. The measurement time is 300 [seconds]. The dead time is at most 30 [%].

[0044] In the case of metal foil, the thickness of the barrier layer 101B should at least function as a barrier layer that prevents moisture from penetrating, and can be, for example, about 5.0 to 1000 μm. The thickness of the barrier layer 101B is preferably about 85 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, and particularly preferably about 35 μm or less. Alternatively, the thickness of the barrier layer 101B is preferably about 9.0 μm or more, even more preferably about 20 μm or more, and even more preferably about 25 μm or more. Furthermore, preferred ranges for the thickness of the barrier layer 52 include approximately 5.0 to 1000 μm, 5.0 to 85 μm, 5.0 to 50 μm, 5.0 to 40 μm, 5.0 to 35 μm, 9.0 to 1000 μm, 9.0 to 85 μm, 9.0 to 50 μm, 9.0 to 40 μm, 9.0 to 35 μm, 20 to 1000 μm, 20 to 85 μm, 20 to 50 μm, 20 to 40 μm, 20 to 35 μm, 25 to 1000 μm, 25 to 85 μm, 25 to 50 μm, 25 to 40 μm, and 25 to 35 μm. When the barrier layer 101B is made of aluminum alloy foil, the above ranges are particularly preferred. Furthermore, from the viewpoint of providing the exterior member 101 with high moldability and high rigidity, the thickness of the barrier layer 101B is preferably about 35 μm or more, more preferably about 45 μm or more, even more preferably about 50 μm or more, even more preferably about 55 μm or more, and also preferably about 200 μm or less, more preferably about 85 μm or less, even more preferably about 75 μm or less, even more preferably about 70 μm or less, and preferably The suitable ranges are approximately 35-200 μm, 35-85 μm, 35-75 μm, 35-70 μm, 45-200 μm, 45-85 μm, 45-75 μm, 45-70 μm, 50-200 μm, 50-85 μm, 50-75 μm, 50-70 μm, 55-200 μm, 55-85 μm, 55-75 μm, and 55-70 μm. The high moldability of the exterior member 101 facilitates deep drawing, which can contribute to increasing the capacity of the energy storage device. Furthermore, while increasing the capacity of the energy storage device increases its weight, the increased rigidity of the exterior member 101 contributes to the high sealing performance of the energy storage device.

[0045] Furthermore, if the barrier layer 101B is a metal foil, it is preferable to provide a corrosion-resistant coating on at least the side opposite to the base layer 101A to prevent dissolution and corrosion. The barrier layer 101B may also have a corrosion-resistant coating on both sides. Here, a corrosion-resistant coating refers to a thin film that provides corrosion resistance (e.g., acid resistance, alkali resistance, etc.) to the barrier layer 101B by performing a corrosion prevention treatment on the surface of the barrier layer 101B, such as a hot water modification treatment like boehmite treatment, a chemical conversion treatment, anodizing treatment, plating treatment with nickel or chromium, or coating agent application. Specifically, a corrosion-resistant coating means a coating that improves the acid resistance of the barrier layer 101B (acid-resistant coating), a coating that improves the alkali resistance of the barrier layer 101B (alkali-resistant coating), etc. One type of treatment may be performed to form the corrosion-resistant coating, or two or more types may be combined. In addition, it is possible to have multiple layers instead of just one layer. Furthermore, among these treatments, hydrothermal modification and anodic oxidation are processes that dissolve the surface of the metal foil with a treatment agent to form a metal compound with excellent corrosion resistance. These treatments may also be included in the definition of chemical conversion treatment. In addition, if the barrier layer 101B has a corrosion-resistant coating, the barrier layer 101B includes the corrosion-resistant coating.

[0046] The corrosion-resistant film prevents delamination between the barrier layer 101B (for example, an aluminum alloy foil) and the base material layer 101A, and between the barrier layer 101B and the heat-sealable resin layer 101C during the molding of the exterior member 101. The corrosion-resistant film prevents dissolution and corrosion of the surface of the barrier layer 101B due to hydrogen fluoride generated by the reaction of an electrolyte and moisture, especially dissolution and corrosion of aluminum oxide present on the surface of the barrier layer 101B when the barrier layer 101B is an aluminum alloy foil. The corrosion-resistant film further improves the adhesiveness (wettability) of the surface of the barrier layer 101B and prevents delamination between the base material layer 101A and the barrier layer 101B, and between the barrier layer 101B and the heat-sealable resin layer 101C during heat sealing. The corrosion-resistant film prevents delamination between the base material layer 101A and the barrier layer 101B, and between the barrier layer 101B and the heat-sealable resin layer 101C during the molding of the exterior member 101.

[0047] In addition, the heat-sealable resin layer 101C included in the exterior member 101 is a layer that imparts sealing properties to the exterior member 101 by heat sealing. Examples of the heat-sealable resin layer 101C include a resin film made of a polyolefin-based resin or an acid-modified polyolefin-based resin obtained by graft-modifying a polyolefin-based resin with an acid such as maleic anhydride. The thickness of the heat-sealable resin layer 101C is not particularly limited as long as the heat-sealable resin layers 101C can exhibit a function of heat-sealing to seal the electrode body 200. For example, it is about 100 μm or less, preferably about 85 μm or less, and more preferably about 15 to 85 μm.

[0048] If the heat-fusible resin layer 101C is too hard, when forming the roll of raw material or the outer material 101 into the outer bag 100 using the apparatus, it may slip at the contact point with the apparatus, making it difficult to transport properly. Furthermore, if scratches occur on the outer material 101 due to this friction, the heat-fusible resin layer 101C will be damaged. Since damage to the heat-fusible resin layer 101C may reduce the heat seal strength, it is preferable that the heat-fusible resin layer has a moderately slippery property. For this reason, when using a non-slip or low-slip material as the material constituting the heat-fusible resin layer 101C, it is preferable to add a lubricant from the viewpoint of transportability.

[0049] Furthermore, from the viewpoint of stain resistance and processability, it is preferable that the tensile modulus of the heat-fusible resin layer 101C, as measured in accordance with the provisions of JIS K7161:2014, falls within the range of 500 MPa to 1000 MPa. More preferable ranges for the tensile modulus of the heat-fusible resin layer 101C include 500 MPa to 800 MPa, even more preferable ranges include 500 MPa to 750 MPa, even more preferable ranges include 500 MPa to 700 MPa, and even more preferable ranges include 510 MPa to 700 MPa.

[0050] The tensile modulus of the heat-fusible resin layer 101C is 500 MPa or higher, which effectively suppresses contamination of the equipment during molding and transport of the outer casing 100. Specifically, because the tensile modulus of the heat-fusible resin layer 101C is 500 MPa or higher, the lubricant located on the surface of the heat-fusible resin layer 101C is less likely to be scraped off by the equipment, etc., so the lubricant located on the surface of the heat-fusible resin layer 101C is less likely to transfer to the equipment, etc., which effectively suppresses contamination of the equipment, etc. Furthermore, because the tensile modulus of the heat-fusible resin layer 101C is 1000 MPa or lower, high sealing strength is achieved by heat sealing. Specifically, because the tensile modulus of the heat-fusible resin layer 101C is 1000 MPa or lower, the heat-fusible resin layer 101C is less likely to become brittle, resulting in high sealing strength through heat sealing. If the tensile modulus of the heat-fusible resin layer 101C exceeds 1000 MPa, the heat-fusible resin layer 101C tends to become brittle, making it prone to delamination from the barrier layer 101B laminated via the adhesive layer, thus reducing the seal strength. Furthermore, stretching at the folding portion during molding of the outer casing 100 can cause whitening or cracking in the stretched portion, potentially reducing battery performance. Additionally, if the tensile modulus of the heat-fusible resin layer 101C exceeds 1000 MPa, its extrudeability decreases, which is a factor in reducing productivity. Therefore, in the outer casing member 101 of the energy storage device 10 of this embodiment, setting the tensile modulus of the heat-fusible resin layer 101C in the range of 500 to 1000 MPa allows for optimal performance of both contamination suppression effects on the device and improved seal strength through heat fusion. The tensile modulus of the heat-fusible resin layer 101C can be adjusted by adjusting the molecular weight, melt mass flow rate (MFR), etc., of the resin constituting the heat-fusible resin layer 101C.

[0051] Furthermore, if the processes of joining the sealing portions for pillow sealing and folding during the bag-making of the outer casing 100 are referred to as processing, the same problems as described above will occur during that processing. In particular, the outer casing member 101 is prone to damage during processing, so solving the above problems is important. By setting the tensile modulus of the heat-fusible resin layer 101C to a range of 500 MPa to 1000 MPa, processing can be performed smoothly.

[0052] The exterior member 101 preferably has one or more layers having a buffering function (hereinafter referred to as "buffering layers") outside the heat-fusible resin layer 101C (upper side in Figure 1B), and more preferably outside the barrier layer 101B. The buffering layers may be laminated on the outside of the base layer 101A, or the base layer 101A may also have the function of a buffering layer. If the exterior member 101 has multiple buffering layers, the multiple buffering layers may be adjacent to each other, or they may be laminated via the base layer 101A or the barrier layer 101B, etc.

[0053] The materials constituting the buffer layer can be arbitrarily selected from materials having cushioning properties. Examples of cushioning materials include rubber, nonwoven fabric, or foamed sheet. Examples of rubber include natural rubber, fluororubber, or silicone rubber. The rubber hardness is preferably around 20 to 90. The materials constituting the nonwoven fabric are preferably materials with excellent heat resistance. When the buffer layer is made of nonwoven fabric, the lower limit of the buffer layer thickness is preferably 100 μm, more preferably 200 μm, and still more preferably 1000 μm. When the buffer layer is made of nonwoven fabric, the upper limit of the buffer layer thickness is preferably 5000 μm, and still more preferably 3000 μm. The preferred range for the thickness of the buffer layer is 100 μm to 5000 μm, 100 μm to 3000 μm, 200 μm to 5000 μm, 200 μm to 3000 μm, 1000 μm to 5000 μm, or 1000 μm to 3000 μm. Among these, the most preferred range for the buffer layer thickness is 1000 μm to 3000 μm.

[0054] When the buffer layer is made of rubber, the lower limit of the buffer layer thickness is preferably 0.5 mm, more preferably 1.0 mm. When the buffer layer is made of rubber, the upper limit of the buffer layer thickness is preferably 10 mm, more preferably 5.0 mm, more preferably 2.0 mm. When the buffer layer is made of rubber, the preferred range of the buffer layer thickness is 1.0 mm to 2.0 mm, 1.0 mm to 5.0 mm, 1.0 mm to 10 mm, 0.5 mm to 2.0 mm, 0.5 mm to 5.0 mm, and 0.5 mm to 10 mm.

[0055] If the exterior member 101 has a buffer layer, the buffer layer functions as a cushion, thus preventing damage to the exterior member 101 from impact when the energy storage device 10 is dropped or from handling during the manufacturing of the energy storage device 10.

[0056] In the exterior body 100 of this embodiment, a deep housing can be formed in the exterior member 101 through cold forming, which increases the weight of the electrode body 200 and increases the impact on the exterior body 100 due to shocks, etc. For this reason, in this embodiment, when the thickness of the exterior member 101 is 195 μm or less and the thickness of the barrier layer 101B is in the range of 20 to 85 μm, it is preferable that the puncture strength when the exterior member 101 is pierced from the base material layer 101A side, as measured by a method in accordance with the provisions of JIS Z1707:1997, is 30 N or more. Preferred ranges for puncture strength include, for example, about 30 to 45 N, about 30 to 40 N, about 35 to 45 N, and about 35 to 40 N. The method for measuring the puncture strength of the exterior member 101 is as follows.

[0057] The puncture strength of the exterior member 101 from the base layer 101A side shall be measured by a method in accordance with the provisions of JIS Z1707:1997. Specifically, in a measurement environment of 23±2℃ and relative humidity (50±5)%, the test piece shall be fixed with a 115mm diameter stand and a pressing plate having a 15mm diameter opening in the center, and a semicircular needle with a diameter of 1.0mm and a tip radius of 0.5mm shall be inserted at a speed of 50±5mm per minute, and the maximum stress until the needle penetrates shall be measured. Five test pieces shall be used, and the average value shall be calculated. If there are not enough test pieces to measure five, the number of measurable pieces shall be measured, and the average value shall be calculated. The puncture strength measuring device shall be the ZP-500N (force gauge) and MX2-500N (measuring stand) manufactured by IMADA Corporation.

[0058] In the energy storage device 10 of this embodiment, as the weight of the electrode bodies 200 increases, friction between the energy storage devices 10 themselves, friction between the energy storage devices 10 and surrounding members, and friction during transport of the energy storage devices 10 are likely to occur. For this reason, in this embodiment, in addition to good ink adhesion (good printing characteristics) on the surface of the base material layer 101A side of the exterior member 101, it is preferable that the fixed ink does not easily disappear. From this viewpoint, it is preferable that the contact angle of the surface of the base material layer 101A side of the exterior member 101 of this embodiment is 80° or less. That is, in the exterior member 101, if the base material layer 101A constitutes the outermost surface, the contact angle of the surface of the base material layer 101A is 80° or less. Also, if the coating layer is provided on the outside of the base material layer 101A, the contact angle of the surface of the coating layer is 80° or less. In this embodiment, since the contact angle of the surface of the exterior member 101 on the base layer 101A side is 80° or less, the ink is less likely to be repelled on the surface of the base layer 101A side, resulting in excellent printability, and furthermore, the fixed ink is less likely to disappear. In particular, when ink is printed by pad printing on an exterior member 101 in which a lubricant is present on the surface of the base layer 101A side to improve moldability, the ink may be repelled on the surface of the base layer 101A side, resulting in printing defects. However, even in such cases, the exterior member 101 of the energy storage device 10 in this embodiment has a contact angle of 80° or less on the surface of the base layer 101A side, so the ink is less likely to be repelled, making it particularly suitable as an exterior member 101 in which printing or the like is formed on the surface of the base layer 101A by pad printing.

[0059] In this embodiment, from the viewpoint of improving printability and making it less likely for the fixed ink to disappear, it is more preferable that the contact angle of the surface on the substrate layer 101A side be 79° or less, and even more preferable that it be 72° or less. The contact angle of the surface on the substrate layer 101A side is measured using an LSE-A210 manufactured by Nick Co., Ltd., by measuring the contact angle of the interface between the substrate and the water droplet 5 seconds after the water droplet is placed on it.

[0060] In this embodiment, the contact angle of the surface on the substrate layer 101A side can be preferably made 80° or less by, for example, applying corona treatment to the surface on the substrate layer 101A side. Corona treatment can be performed by irradiating the surface on the substrate layer 101A side with corona discharge using a commercially available corona surface treatment device. The conditions for corona treatment can be such that, for example, by treating the surface on the substrate layer 101A side with an irradiation output of 1 kW or more and a speed of 10 MT / min, the contact angle of the surface on the substrate layer 101A side can be made 80° or less.

[0061] Furthermore, when printing ink on the surface of the exterior member 101, a step is performed to print ink on at least a portion of the surface of the base layer 101A after corona treatment. The printing method is not particularly limited, but when printing on the exterior member 101 after molding, inkjet printing and pad printing are preferred. In this embodiment, since the contact angle of the surface of the exterior member 101 on the base layer 101A side is set to 80° or less, ink can be suitably printed even by pad printing, where ink is easily repelled on the base layer 101A where a lubricant is present on the surface. Therefore, for example, barcodes, patterns, characters, etc. can be suitably formed on at least a portion of the surface of the base layer 101A.

[0062] Figure 4 is a side view showing the state in which the outer covering member 101 is wrapped around the electrode body 200 during the manufacturing process of the energy storage device 10. As shown in Figure 4, the outer covering member 101 is wrapped around the electrode body 200. In this case, the outermost layer of the electrode body 200 does not necessarily have to be an electrode; for example, it may be a protective tape or a separator. With the outer covering member 101 wrapped around the electrode body 200, the first sealing portion 110 is formed by heat sealing the opposing surfaces (heat-fusible resin layers) of the outer covering member 101 together.

[0063] The base portion of the first sealing portion 110 is preferably located on the edge 135 of the outer casing 100. In this embodiment, the edge 135 is formed at the boundary between the first surface 130 and the second surface 140, which has a smaller area than the first surface 130. That is, in this embodiment, the base portion of the first sealing portion 110 is formed at the boundary between the first surface 130 and the second surface 140, and does not exist on either the first surface 130 or the second surface 140. The base portion of the first sealing portion 110 may be located somewhere other than the edge 135. That is, the base portion of the first sealing portion 110 may be located on any surface of the outer casing 100, such as the first surface 130 or the second surface 140. In the energy storage device 10, the first sealing portion 110 is bent towards the second surface 140 with the edge 135 as the center. In the energy storage device 10, the first sealing portion 110 is in contact with the second surface 140 and covers substantially the entire second surface 140. "Substantially the entire second surface 140" means the area occupying 75% or more of the area of ​​the second surface 140.

[0064] In other words, in the energy storage device 10, the first sealing portion 110 is not formed on the first surface 130, which has a large surface area. The first surface 130 is flatter than the case where a sealing portion such as the first sealing portion 110 is in contact with the first surface 130. Therefore, even if another energy storage device 10 is placed on the first surface 130, the other energy storage device 10 will not tilt. As a result, with the energy storage device 10, when multiple energy storage devices 10 are stacked, unevenness in the pressure distribution applied to the lower energy storage device 10 can be suppressed. In other words, when multiple energy storage devices 10 are stacked to form a module, the first sealing portion 110 is not placed on the surface (first surface 130) adjacent to the adjacent energy storage device 10. Furthermore, in all-solid-state batteries, this configuration is preferable from the viewpoint that it is necessary to apply high pressure uniformly from the outside of the battery in order to achieve battery performance.

[0065] Furthermore, in the energy storage device 10, the base portion of the first sealing portion 110 is located on the edge 135 of the outer casing 100. Therefore, with the energy storage device 10, a wider bonding area can be secured in the first sealing portion 110 compared to when the base portion of the first sealing portion 110 is located on the second surface 140 (for example, the central portion of the second surface 140 in the direction of arrow UD). Note that the bonding area of ​​the first sealing portion 110 does not necessarily have to be the entire area of ​​the first sealing portion 110, but may be a part of the first sealing portion 110, such as only the vicinity of the base portion of the first sealing portion 110.

[0066] Furthermore, in the energy storage device 10, substantially the entire second surface 140 is covered by the first sealing portion 110. That is, in the energy storage device 10, the length of the first sealing portion 110 in the direction of arrow UD is longer compared to, for example, the case where the first sealing portion 110 covers less than half of the area of ​​the second surface 140 (see Figure 3). Therefore, with the energy storage device 10, a wide bonding area can be secured in the first sealing portion 110. Also, since substantially the entire second surface 140 is covered by the first sealing portion 110, the energy storage device 10 remains stable even if it is positioned upright so that the second surface 140 is in contact with the mounting surface. That is, the energy storage device 10 is less likely to tilt relative to the mounting surface. Therefore, such a configuration is effective, for example, when multiple energy storage devices 10 are arranged side by side to form a module.

[0067] Figure 5 is a view from below showing the state in which the outer casing member 101 is wrapped around the electrode body 200 during the manufacturing process of the energy storage device 10. As shown in Figure 5, in the energy storage device 10, the direction along the edge 135 is the TD (Transverse Direction) of the outer casing member 101, and the direction perpendicular to the edge 135 is the MD (Machine Direction) of the outer casing member 101. That is, the direction along the edge 135 is the direction (TD) perpendicular to the flow direction (MD) of the outer casing member 101.

[0068] In the energy storage device 10, the first sealing portion 110 is bent along the edge 135, and the direction along the edge 135 is perpendicular to the flow direction of the outer casing member 101. Therefore, with the energy storage device 10, even if a fold is formed in a direction perpendicular to the flow direction of the outer casing member 101, the outer casing member 101 is less likely to break, thus reducing the possibility of the first sealing portion 110 breaking due to bending.

[0069] The flow direction (MD) of the exterior member 101 corresponds to the rolling direction (RD) of the metal foil (aluminum alloy foil, etc.) of the barrier layer contained in the exterior member 101. The TD of the exterior member 101 corresponds to the TD of the metal foil. The rolling direction (RD) of the metal foil can be determined by the rolling pattern.

[0070] Furthermore, by observing multiple cross-sections of the heat-fusible resin layer of the exterior member 101 with an electron microscope to confirm the sea-island structure, the direction parallel to the cross-section where the average diameter of the islands in the direction perpendicular to the thickness direction of the heat-fusible resin layer (hereinafter also referred to as the "length direction of the heat-fusible resin layer") was maximum can be determined as the MD. This method can be used to identify the MD of the exterior member 101 when it cannot be identified by the rolling marks of the metal foil.

[0071] Specifically, the sea-island structure is confirmed by observing electron microscope images of each of the following cross-sections (a total of 10 cross-sections): a cross-section along the length of the heat-fusible resin layer, and cross-sections at 10-degree increments from a direction parallel to the length of the heat-fusible resin layer, up to a direction perpendicular to the length of the layer. Next, the diameter d of each island on each cross-section is measured by the straight-line distance connecting the two ends in a direction perpendicular to the thickness direction of the heat-fusible resin layer. Then, for each cross-section, the average of the top 20 island diameters d is calculated. Finally, the direction parallel to the cross-section with the largest average island diameter d is determined to be the MD (Metropolitan Distance).

[0072] Figure 6 is a schematic diagram showing a part of the VI-VI cross-section in Figure 2. As shown in Figure 6, the second sealing portion 120 is sealed with the outer casing 100 sandwiching the electrode terminals 300.

[0073] Figure 7 is a diagram illustrating the method for forming the second sealing portion 120. As shown in Figure 7, the exterior member 101 is folded, and the second sealing portion 120 is formed by heat sealing the opposing surfaces (heat-fusible resin layers) of the exterior member 101 together. Although not shown in Figure 7, electrode terminals 300 are located between the opposing surfaces of the exterior member 101. An adhesive film that adheres to both metal and resin may be placed between the electrode terminals 300 and the exterior member 101.

[0074] The adhesive film can consist of one or more layers of a resin film made of a polyolefin resin or an acid-modified polyolefin resin obtained by grafting a polyolefin resin with an acid such as maleic anhydride. When there are two or more layers of adhesive film, it is preferable to place the resin film made of polyolefin resin on the side that is joined to the exterior member 101. When there are two or more layers of adhesive film, it is preferable to place the resin film made of an acid-modified polyolefin resin obtained by grafting a polyolefin resin with an acid such as maleic anhydride on the side that is joined to the electrode terminal 300.

[0075] Referring again to Figure 6, the electrode body 200 includes a plurality of electrodes 210 (positive and negative electrodes). Current collectors 215 extending from each electrode 210 are connected to electrode terminals 300. In the energy storage device 10, a portion of the electrode terminals 300 that is outside the outer casing 100 is located at approximately half the thickness of the energy storage device 10 in the thickness direction of the energy storage device 10. That is, length L2 is approximately half the length L1. Note that "approximately half the thickness of the energy storage device 10" means 35% to 65% of the thickness of the energy storage device 10.

[0076] Therefore, with the energy storage device 10, for example, compared to the case where the electrode terminal 300 is located at approximately the same position as the first surface 130 in the thickness direction of the energy storage device 10, the difference between the longest distance and the shortest distance between each of the multiple electrodes 210 and the electrode terminal 300 can be reduced.

[0077] <1-2. Method for Manufacturing an Energy Storage Device> Figure 8 is a flowchart showing an example of the manufacturing procedure for the energy storage device 10. The steps shown in Figure 8 are performed, for example, by a manufacturing apparatus for the energy storage device 10. Note that the manufacturing procedure for the energy storage device 10 can be changed as needed.

[0078] The manufacturing apparatus manufactures the exterior member 101 (step S100). The manufacturing apparatus wraps the exterior member 101 around the electrode body 200 (step S110). The manufacturing apparatus forms the first sealing portion 110 by heat sealing the opposing surfaces (heat-fusible resin layers) of the exterior member 101 together (step S120). This results in the unfinished product shown in Figures 4 and 5.

[0079] The manufacturing apparatus bends the first sealing portion 110 so that it contacts the second surface 140 (step S130). The manufacturing apparatus folds the outer casing member 101 with the electrode body 200 housed inside, and forms the second sealing portion 120 by heat sealing the opposing surfaces (heat-fusible resin layers) of the outer casing member 101 together (step S140). This completes the energy storage device 10.

[0080] <1-3. Features> The barrier layer 101B of the energy storage device 10 according to this embodiment 1 contains 50% by mass or more of recycled aluminum alloy. The recycled aluminum alloy is recycled 1000 series aluminum alloy, recycled 3000 series aluminum alloy, or recycled 5000 series aluminum alloy, which have high corrosion resistance to electrolytes or all-solid electrolytes. Therefore, the exterior member 101 can reduce environmental impact and has high corrosion resistance.

[0081] In the energy storage device 10 according to this first embodiment, the first sealing portion 110 is folded towards the smaller second surface 140. That is, the first sealing portion 110 does not exist on the larger first surface 130. Therefore, even if another energy storage device 10 is placed on the first surface 130, the other energy storage device 10 will not tilt. As a result, the energy storage device 10 can suppress uneven pressure distribution on the lower energy storage device 10 when multiple energy storage devices 10 are stacked. Furthermore, when used in an all-solid-state battery, it is necessary to apply high pressure uniformly from the outside of the battery in order to achieve battery performance, so the packaging form of the present invention is preferred. In addition, in the energy storage device 10, the base portion of the first sealing portion 110 is located on the side 135 of the outer casing 100. Therefore, with the energy storage device 10, when the first sealing portion 110 is placed on the second surface 140, a wider bonding width can be secured in the first sealing portion 110 compared to when the base portion of the first sealing portion 110 is on the second surface 140.

[0082] [2. Embodiment 2] In the energy storage device 10 according to Embodiment 1 described above, the second sealing portion 120 is formed by folding the exterior member 101 and heat-sealing the opposing surfaces of the exterior member 101 together. However, the shape and formation method of the second sealing portion 120 are not limited thereto. In the following, we will mainly describe the parts that differ from Embodiment 1, and will omit the description of parts that are common to Embodiment 1.

[0083] <2-1. Configuration of the Energy Storage Device> Figure 9 is a schematic plan view showing the energy storage device 10X according to this embodiment 2. Figure 10 is a schematic side view showing the energy storage device 10X. Figure 11 is a schematic perspective view showing the lid 400.

[0084] Referring to Figures 9, 10, and 11, the outer casing 100X is constructed by fitting lids 400 into each of the openings at both ends of the outer casing member 101 that is wrapped around the electrode body 200. With the lids 400 fitted, the second sealing portion 120X is formed by heat sealing the outer casing member 101 and the lids 400.

[0085] The lid 400 is a bottomed tray-shaped member with a rectangular shape in plan view, and is formed by, for example, cold forming the exterior member 101. The lid 400 does not necessarily have to be made of the exterior member 101; it may be a metal molded product or a resin molded product. In the energy storage device 10X, the lid 400 is positioned such that its bottom surface is located inside the exterior member 100X. However, in the energy storage device 10X, the bottom surface of the lid 400 does not necessarily have to be located inside the exterior member 100X. In the energy storage device 10X, the bottom surface of the lid 400 may be located outside the exterior member 100X. If the lid 400 is a metal molded product or a resin molded product, it is preferable that the material constituting the lid 400 has a certain thickness so that deformation of the exterior member 100X is suppressed even when the energy storage devices 10X are stacked. The minimum thickness of the material constituting the lid 400 is, for example, 1.0 mm, more preferably 3.0 mm, and even more preferably 4.0 mm. The maximum thickness of the material constituting the lid 400 is, for example, 20 mm, more preferably 15 mm, and even more preferably 10 mm. The maximum thickness of the material constituting the lid 400 may be 20 mm or more. The preferred range of thickness for the material constituting the lid 400 is 1.0 mm to 20 mm, 1.0 mm to 15 mm, 1.0 mm to 10 mm, 3.0 mm to 20 mm, 3.0 mm to 15 mm, 3.0 mm to 10 mm, 4.0 mm to 20 mm, 4.0 mm to 15 mm, and 4.0 mm to 10 mm. In this disclosure, when the lid 400 is described as a metal molded product or a resin molded product, the lid 400 does not include an embodiment composed solely of film. Film refers to, for example, a film as defined by the JIS (Japanese Industrial Standards) [Packaging Terminology] standard. Furthermore, the film specified by the JIS [Packaging Terminology] standard is a plastic film with a thickness of less than 250 μm. The thickness of the material constituting the lid 400 may vary depending on the part of the lid 400. If the thickness of the material constituting the lid 400 varies depending on the part of the lid 400, the thickness of the material constituting the lid 400 shall be the thickness of the thickest part.

[0086] Furthermore, with the electrode body 200 housed, the electrode terminal 300 protrudes to the outside of the outer casing 100X through the gap between the lid 400 and the outer casing member 101. That is, the lid 400 and the outer casing member 101 are heat-sealed with the electrode terminal 300 sandwiched between them. Note that in the energy storage device 10X, the position where the electrode terminal 300 protrudes to the outside does not necessarily have to be between the lid 400 and the outer casing member 101. For example, the electrode terminal 300 may protrude to the outside through a hole formed on any of the six surfaces of the outer casing 100X. In this case, the small gap between the outer casing 100X and the electrode terminal 300 is filled, for example, with resin.

[0087] Furthermore, in the energy storage device 10X, the cover 400 and the electrode terminals 300 are provided as separate components. However, the cover 400 and the electrode terminals 300 do not necessarily have to be provided as separate components. For example, the cover 400 and the electrode terminals 300 may be formed integrally.

[0088] Figure 12 shows a first example in which the lid 400 and the electrode terminal 300 are integrally formed. As shown in Figure 12, in the first example, the electrode terminal 300 is preheat-sealed to the side surface of the lid 400. If, for example, the lid 400 is made of an exterior member 101, an adhesive film that adheres to both the metal and resin described in Embodiment 1 may be placed between the lid 400 and the electrode terminal 300. If there are two or more layers of adhesive film, it is preferable to place a resin film made of polyolefin resin on the side that is joined to the lid 400. If there are two or more layers of adhesive film, it is preferable to place a resin film made of acid-modified polyolefin resin, which is obtained by graft-modifying polyolefin resin with an acid such as maleic anhydride, on the side that is joined to the electrode terminal 300.

[0089] Figure 13 shows a second example in which the lid 400 and the electrode terminal 300 are integrally formed. As shown in Figure 13, in the second example, the electrode terminal 300 passes through a hole formed in the bottom surface of the lid 400. The small gap in the hole in the bottom surface of the lid 400 is filled with, for example, resin.

[0090] Furthermore, in the energy storage device 10X, a gas valve may be installed in a hole formed in the second sealing portion 120X or in any of the six surfaces of the outer casing 100X. The gas valve is composed of, for example, a check valve or a break valve and is configured to reduce the pressure inside the outer casing 100X when the pressure inside the outer casing 100X rises due to gas generated inside the energy storage device 10X.

[0091] <2-2. Method for Manufacturing Energy Storage Devices> Figure 14 is a flowchart showing an example of the manufacturing procedure for energy storage device 10X. The steps shown in Figure 14 are performed, for example, by a manufacturing apparatus for energy storage device 10X. Note that the manufacturing procedure for energy storage device 10X can be modified as needed.

[0092] The manufacturing apparatus wraps the outer casing member 101 around the electrode body 200 (step S200). The manufacturing apparatus forms the first sealing portion 110 by heat sealing the opposing surfaces (heat-fusible resin layers) of the outer casing member 101 together (step S210). This produces the unfinished product shown in Figures 4 and 5.

[0093] The manufacturing apparatus bends the first sealing portion 110 so that it contacts the second surface 140 (step S220). The manufacturing apparatus places the electrode body 200 into the unfinished product created in step S220 and attaches the lids 400 to each of the openings at both ends (step S230). The manufacturing apparatus forms the second sealing portion 120X by heat sealing the exterior member 101 and the lids 400 (step S240). This completes the energy storage device 10X.

[0094] <2-3. Features> In the energy storage device 10X according to this second embodiment, the first sealing portion 110 is bent towards the second surface 140, which has a smaller area. Therefore, with the energy storage device 10X, when multiple energy storage devices 10X are stacked, unevenness in the pressure distribution applied to the lower energy storage device 10X can be suppressed.

[0095] <2-4. Other Features> In the energy storage device 10X according to this second embodiment, the first sealing portion 110 does not necessarily have to be folded toward the second surface 140 which has a smaller area. For example, the first sealing portion 110 may be folded toward the first surface 130 which has a larger area. Also, the base portion of the first sealing portion 110 does not necessarily have to be on the edge 135 of the outer casing 100X. The base portion of the first sealing portion 110 may be located on a surface other than the lid 400 of the outer casing 100X, for example. Even in this case, the energy storage device 10X according to this second embodiment includes the following features, for example.

[0096] The energy storage device 10X comprises an electrode body (electrode body 200) and an outer casing (outer casing 100X) that seals the electrode body (electrode body 200). The outer casing (outer casing 100X) is wrapped around the electrode body (electrode body 200) and includes an outer casing member (outer casing member 101) with openings formed at both ends, and a lid (lid 400) that seals the openings.

[0097] In the energy storage device 10X, the second sealing portion 120X is not formed by heat sealing the opposing surfaces of the exterior member 101 as in Embodiment 1 (see Figure 7). In the energy storage device 10X, the opening of the exterior member 101 wrapped around the electrode body 200 is sealed by the cover 400. That is, the second sealing portion 120X is formed in the portion where the cover 400 and the exterior member 101 overlap (see Figures 9 and 10). With this configuration, the area of ​​the second sealing portion 120X can be easily narrowed by adjusting the depth L3 of the cover 400 (Figure 11).

[0098] Furthermore, in the energy storage device 10X, at the position where the corner C1 of the electrode body 200 (Figures 9 and 10) is covered by the outer casing member 101, excessive load is not generated due to the corner C1 piercing the outer casing member 101. As described above, in the energy storage device 10X, the second sealing portion 120X is not formed by heat sealing the opposing surfaces of the outer casing member 101 as in Embodiment 1.

[0099] Furthermore, the manufacturing procedure for the energy storage device 10X is not limited to the procedure shown in the flowchart of Figure 14. For example, the energy storage device 10X may be manufactured using the procedure shown in the flowchart of Figure 15.

[0100] Figure 15 is a flowchart showing another manufacturing procedure for the energy storage device 10X according to Embodiment 2. The steps shown in Figure 15 are performed, for example, by a manufacturing apparatus for the energy storage device 10X. The manufacturing apparatus attaches a component in which the electrode terminals 300 and the lid 400 are integrated (for example, the component shown in Figures 12 and 13) to the electrode body 200 (step S250). For example, the electrode terminals 300 are welded to the electrode body 200. Then, the manufacturing apparatus wraps the outer casing member 101 around the electrode body 200 (step S260). The manufacturing apparatus forms a first sealing portion 110 by heat sealing the opposing surfaces (heat-fusible resin layers) of the outer casing member 101 together, and forms a second sealing portion 120X by heat sealing the outer casing member 101 and the lid 400 (step S270). This completes the energy storage device 10X. The energy storage device 10X may be manufactured by such a procedure.

[0101] [3. Embodiment 3] In the battery manufacturing process, it is common to age a temporarily sealed energy storage device in a predetermined temperature environment for a predetermined time (hereinafter referred to as the aging process) for purposes such as impregnating the electrode body with electrolyte. During the aging process, gas is generated from the electrode body 200 and it is necessary to discharge this gas to the outside of the battery. In the energy storage device 10X according to Embodiment 2 described above, there was no mechanism to remove the gas generated in the aging process at the final stage of manufacturing the energy storage device 10X. In the energy storage device 10Y according to Embodiment 3, a mechanism is provided to remove the gas generated from the electrode body 200 at the final stage of manufacturing the energy storage device 10Y. In the following, the differences from Embodiment 2 will be described in detail, and the parts common to Embodiment 2 will not be described.

[0102] <3-1. Configuration of the Energy Storage Device> Figure 16 is a side view showing the state in which the outer casing member 101Y is wrapped around the electrode body 200 during the manufacturing process of the energy storage device 10Y. Figure 17 is a bottom view showing the state in which the outer casing member 101Y is wrapped around the electrode body 200 and the cover 400 is attached to the outer casing member 101Y during the manufacturing process of the energy storage device 10Y.

[0103] As shown in Figures 16 and 17, the piece 150 is formed with the outer covering member 101Y wrapped around the electrode body 200. The piece 150 is formed by joining opposing surfaces of the outer covering member 101Y with the outer covering member 101Y wrapped around the electrode body 200. More specifically, the piece 150 is formed by joining (heat sealing) the periphery of opposing surfaces of the outer covering member 101Y with the outer covering member 101Y wrapped around the electrode body 200. That is, a first sealing portion 154 is formed on the periphery of the piece 150.

[0104] Furthermore, in one portion 150, a space 152 is formed where the opposing surfaces of the exterior member 101Y are not joined. Near the edge 135, joined regions 151 where the opposing surfaces of the exterior member 101Y are joined and unjoined regions 153 where the opposing surfaces of the exterior member 101Y are not joined are arranged alternately. In other words, in one portion 150, a pattern of joined regions 151 is formed along the edge 135.

[0105] The gas generated from the electrode body 200 is discharged to the outside of the outer casing 100Y by releasing the seal on the outer casing 100Y, for example, by cutting off a portion of the piece 150. Note that the gas discharged to the outside of the outer casing 100Y is not necessarily limited to the gas generated from the electrode body 200; it may be air, water vapor, hydrogen sulfide, or other gases not generated from the electrode body 200.

[0106] Subsequently, the outer casing 100Y is sealed again by heat-sealing the portion including the vicinity of edge 135 in a strip shape. This completes the energy storage device 10Y. In the completed energy storage device 10Y, regions with strong bonding forces between opposing surfaces of the outer casing member 101Y and regions with weak bonding forces are alternately arranged along edge 135. In other words, in the heat-sealed portion near edge 135, thin and thick portions are alternately arranged along edge 135. This is because, when the vicinity of edge 135 is heat-sealed again, the unjointed region 153 is single-sealed, while the joined region 151 is double-sealed.

[0107] <3-2. Method for Manufacturing an Energy Storage Device> Figure 18 is a flowchart showing an example of the manufacturing procedure for the energy storage device 10Y. The steps shown in Figure 18 are performed, for example, by a manufacturing apparatus for the energy storage device 10Y. Note that the manufacturing procedure for the energy storage device 10Y can be changed as needed.

[0108] The manufacturing apparatus wraps the outer casing member 101Y around the electrode body 200 (step S300). The manufacturing apparatus forms the first sealing portion 154 by heat sealing the periphery of the outer casing member 101Y's opposing surfaces (heat-fusible resin layer) (step S310). The manufacturing apparatus forms the pattern of the joining region 151 by heat sealing the opposing surfaces of the outer casing member 101Y near the edge 135 (step S320).

[0109] In step S320, the manufacturing apparatus attaches the lids 400 to each of the openings at both ends of the unfinished product with the electrode body 200 housed inside (step S330). The manufacturing apparatus forms the second sealing portion 120X by heat sealing the exterior member 101Y and the lid 400 (step S340). After that, it undergoes an aging process.

[0110] The manufacturing apparatus degassed the gas generated during the aging process by cutting off the piece 150 (step S350). The manufacturing apparatus resealed the outer casing 100Y by heat-sealing the portion of the piece 150 including the joining region 151 in a strip shape and removing the edges (step S360). After that, the piece 150 was bent toward the second surface 140 to complete the energy storage device 10Y.

[0111] <3-3. Features> In the energy storage device 10Y according to this embodiment 3, the piece 150 including the first sealing portion 154 is folded towards the second surface 140, which has a smaller area. Therefore, with the energy storage device 10Y, when multiple energy storage devices 10Y are stacked, unevenness in the pressure distribution applied to the lower energy storage device 10Y can be suppressed. When used in all-solid-state batteries, it is necessary to apply high pressure uniformly from the outside of the battery in order to achieve battery performance, so the packaging form of the present invention is preferred.

[0112] [4. Embodiment 4] In the energy storage device 10X according to Embodiment 2 described above, the position where the electrode terminal 300 protrudes to the outside was between the cover 400 and the exterior member 101. However, the position where the electrode terminal 300 protrudes to the outside is not limited to this. In the following, we will mainly describe the parts that differ from Embodiment 2, and will omit the explanation of parts that are common with Embodiment 2.

[0113] <4-1. Configuration of the Energy Storage Device> Figure 19 is a schematic plan view showing an energy storage device 10XA according to this embodiment 4. Figure 20 is a schematic side view showing an energy storage device 10XA. The outer casing 100X of the energy storage device 10XA includes a pair of long sides 100XA and a pair of short sides 100XB in a plan view. The outer casing 100X is constructed by fitting a cover 400 into each of the openings along the long sides 100XA of the outer casing member 101 wrapped around the electrode body 200. With the cover 400 fitted, a second sealing portion 120X is formed by heat sealing the outer casing member 101 and the cover 400. Through holes (not shown) are formed in the cover 400. The two electrode terminals 300 protrude to the outside of the outer casing 100X from the through holes in the cover 400. The two electrode terminals 300 are shaped to follow the long side 100XA of the outer casing 100X. The small gap between the through hole and the electrode terminal 300 is filled with, for example, resin. In this fourth embodiment, the first sealing portion 110 is formed on one of the pair of short sides 100XB.

[0114] In the thickness direction (arrow UD direction) of the energy storage device 10XA, the position in which the electrode terminals 300 protrude from the cover 400 can be arbitrarily selected. In this embodiment 4, as shown in Figure 20, the electrode terminals 300 protrude from approximately the center of the cover 400 to the outside of the outer casing 100X in the thickness direction of the energy storage device 10XA. The length of the electrode terminals 300 in the depth direction (arrow FB direction) of the energy storage device 10XA can be arbitrarily selected. In this embodiment 4, the length of the electrode terminals 300 in the depth direction (arrow FB direction) of the energy storage device 10XA is substantially the same as the length of the electrode body 200.

[0115] <4-2. Features> In the energy storage device 10XA according to this embodiment 4, the electrode terminals 300 are arranged along the longer side 100XA, which has a longer length in the depth direction, so that larger electrode terminals 300 can be used. Therefore, a high-output energy storage device 10XA can be provided.

[0116] [5. Modifications] The above embodiments are examples of possible forms of the exterior component for an energy storage device, the energy storage device, and the method for manufacturing the energy storage device according to the present invention, and are not intended to limit their forms. The exterior component for an energy storage device, the energy storage device, and the method for manufacturing the energy storage device according to the present invention may take forms different from those exemplified in the above embodiments. One example is a form in which a part of the configuration of each of the above embodiments is replaced, modified, or omitted, or a form in which a new configuration is added to each of the above embodiments. Several examples of modifications of each of the above embodiments are shown below. Note that the above embodiments can also be combined to the extent that they are not technically contradictory.

[0117] <5-1> In the above embodiment 1-4, one outer covering member was wrapped around the electrode body 200. However, the outer covering member wrapped around the electrode body 200 does not necessarily have to be one. For example, two or more outer covering members may be wrapped around the electrode body 200.

[0118] Figure 21 is a side view showing the state in which the outer covering members 101Z1 and 101Z2 are wrapped around the electrode body 200 during the manufacturing process of a modified energy storage device. As shown in Figure 21, the electrode body 200 is surrounded by the outer covering members 101Z1 and 101Z2. The first sealing portion 110Z is formed by joining the opposing surfaces of the outer covering members 101Z1 and 101Z2. In this example, each first sealing portion 110Z is bent towards the second surface 140Z side, rather than towards the first surface 130Z side. Even with this configuration, it is possible to suppress uneven pressure distribution on the lower energy storage devices when multiple energy storage devices are stacked. When used in all-solid-state batteries, it is necessary to apply high pressure uniformly from the outside of the battery in order to achieve battery performance, so the packaging form of the present invention is preferred. In this example, each first sealing portion 110Z does not necessarily need to be bent. Furthermore, in this modified example, each sealing portion 110Z may be sealed while sandwiching a part of the electrode terminal 300. Moreover, in this modified example, each first sealing portion 110Z does not need to be formed on the edge 135Z, but may protrude outward from approximately the center of the second surface 140Z in the thickness direction of the energy storage device.

[0119] <5-2> In the above embodiment 1-4, the electrode body 200 was a so-called stack type, formed by stacking a plurality of electrodes 210, but the form of the electrode body 200 is not limited thereto. The electrode body 200 may be a so-called wound type, formed by winding a positive electrode and a negative electrode via a separator. Alternatively, the electrode body 200 may be formed by stacking a plurality of so-called wound type electrode bodies.

[0120] <5-3> In the above embodiment 1-4, the second surface 140 was a plane extending downward from the first surface 130 at approximately a right angle. However, the shape of the second surface 140 is not limited to this. For example, consider the case where the electrode body 200 is a wound electrode body and a plane and a curved surface are formed on its outer circumference. Here, suppose the area of ​​the plane is larger than the area of ​​the curved surface, the first surface 130 covers the plane of the electrode body, and the second surface 140 covers the curved surface of the electrode body. In this case, the second surface 140 may be composed of a curved surface. In this case, the boundary portion where the second surface 140 extends downward from the first surface 130 is the edge 135.

[0121] <5-4> In the above embodiment 3, four joining regions 151 were formed. However, the number of locations where joining regions 151 are formed is not limited to this. For example, the joining regions 151 may be formed at two locations near both ends along the edge 135, or at one location near the center of the edge 135, or at five or more locations.

[0122] <5-5> Furthermore, in the above embodiment 2, the electrode terminal 300 is arranged in the second sealing portion 120X, but the position in the outer casing 100X where the electrode terminal 300 is arranged is not limited to this. For example, as shown in Figure 22, in the above embodiment 2, the electrode terminal 300 can also be arranged in the first sealing portion 110. In other words, the first sealing portion 110 is sealed with the electrode terminal 300 sandwiched between them. In this modified example, at least one of the two electrode terminals 300 may be bent toward the second surface 140, or be bent toward the opposite side of the second surface 140, or may not be bent so as to protrude outward from the edge 135. In this modified example, the electrode terminal 300 and the first sealing portion 110 can be easily sealed, thereby improving the airtightness of the outer casing 100X. Also, the electrode body 200 can be easily housed in the outer casing 100X. In this modified example, for instance, as in Embodiment 2 above, the lids 400 are fitted into each of the openings at both ends of the exterior member 101X. With the lids 400 fitted, the second sealing portion 120 is formed by heat sealing the exterior member 101X and the lids 400. In Embodiment 1 as well, the electrode terminals 300 may be placed in the first sealing portion 110.

[0123] <5-6> Furthermore, in the above embodiment 2, the configuration of the lid 400 can be arbitrarily changed. Figure 23 is a perspective view showing a modified lid 500 of the lid 400. The lid 500 is, for example, plate-shaped and includes a first surface 500A facing the electrode body 200 (see Figure 9), and a second surface 500B opposite to the first surface 500A. A hole 500C is formed in the center of the lid 500, penetrating the first surface 500A and the second surface 500B. The material constituting the lid 500 is, for example, resin. In this modified example, it is preferable that an adhesive film 530 is attached to a predetermined range of the electrode terminal 300, including the portion of the electrode terminal 300 that is joined to the lid 500, and to adhere to both the electrode terminal 300 and the lid 500. The specifications of the adhesive film 530 are the same as those of the adhesive film described in embodiment 1. In this modified example, the method for manufacturing the energy storage device 10X may include the steps of electrically connecting the electrode body 200 and the electrode terminal 300, manufacturing a cover 500, and inserting the electrode terminal 300, which is connected to the electrode body 200, into the hole 500C of the cover 500 (see Figure 24; hereinafter referred to as the "insertion step").

[0124] When the lid 500 is plate-shaped, it is preferable that the lid 500 has a certain thickness so as to suppress deformation of the outer casing 100X even when the energy storage devices 10X are stacked on top of each other. From another viewpoint, when the lid 500 is plate-shaped, it is preferable that the sides of the lid 500 have a certain thickness so as to allow for suitable heat sealing of the sides of the lid 500 and the outer casing member 101X when forming the second sealing portion 120X. The minimum thickness of the lid 500 is, for example, 1.0 mm, more preferably 3.0 mm, and even more preferably 4.0 mm. The maximum thickness of the lid 500 is, for example, 20 mm, more preferably 15 mm, and even more preferably 10 mm. The maximum thickness of the lid 500 may be 20 mm or more. The preferred thickness ranges for the material constituting the lid 500 are 1.0 mm to 20 mm, 1.0 mm to 15 mm, 1.0 mm to 10 mm, 3.0 mm to 20 mm, 3.0 mm to 15 mm, 3.0 mm to 10 mm, 4.0 mm to 20 mm, 4.0 mm to 15 mm, and 4.0 mm to 10 mm. In this disclosure, when the lid 500 is described as being plate-like, the lid 500 does not include a form composed solely of film as defined by the JIS (Japanese Industrial Standards) [Packaging Terminology] standard. The thickness of the lid 500 may vary depending on the part of the lid 500. If the thickness of the lid 500 varies depending on the part, the thickness of the lid 500 is the thickness of the thickest part.

[0125] The lid 500 may be made of a member divided into a first part 510 and a second part 520, and manufactured by joining the first part 510 and the second part 520 so as to sandwich the electrode terminal 300 and the adhesive film 530. In these modified versions, if a gap occurs between the adhesive film 530 and the hole 500C, it is preferable to fill this gap with a resin material such as hot melt or by resin welding.

[0126] When the cover 500 is composed of a member divided into a first part 510 and a second part 520, the relationship between the width LA of the electrode terminal 300 and the width LB of the cover 500 can be arbitrarily selected. From the viewpoint of more firmly joining the electrode terminal 300 and the cover 500, it is preferable that the ratio RA of width LA to width LB is 50% or more. In the example shown in Figure 25, width LA and width LB are substantially equal, in other words, the ratio RA is 100%. When the ratio RA is 50% or more, the area of ​​the electrode terminal 300 that is joined to the cover 500 is large, so by heating the electrode terminal 300, the electrode terminal 300 and the cover 500 can be joined more firmly. In this modified example, it is preferable that the width LC of the adhesive film 530 is substantially equal to the width LA of the electrode terminal 300.

[0127] The cover 500 may be manufactured by insert molding the cover 500 onto the electrode terminal 300 with the adhesive film 530 attached. In this case, the method for manufacturing the energy storage device 10X includes the steps of electrically connecting the electrode body 200 and the electrode terminal 300, and insert molding the cover 500 onto the electrode terminal 300 with the electrode body 200 connected (hereinafter referred to as the "insert molding step"). After the insert molding step, the exterior member 101 is wrapped around the electrode body 200 and the cover 500. In the insert molding step, it is preferable to place an insulating material to protect the electrode body 200 between the portion where the electrode body 200 and the cover 500 are formed. It is preferable to remove the insulating material after the insert molding step.

[0128] Furthermore, in these modified versions, as shown in Figure 26, the exterior body 100X may have a second sealing portion 120X formed by joining the exterior member 101 and the second surface 500B of the lid 500 while the lid 500 is fitted into place. The means for joining the exterior member 101 and the second surface 500B of the lid 500 is, for example, heat sealing. In this modified version, the exterior member 101 is joined to a wider area of ​​the lid 500, thereby improving the airtightness of the exterior body 100X. Alternatively, the lid may be formed by folding the adhesive film 530, and the second sealing portion 120X may be formed by joining any part of the adhesive film 530 to the exterior member 101X. In addition, in these modified versions, it is preferable that a barrier layer is laminated on at least a part of the surface of the lid 500. Or, if the lid 500 has multiple layers, a barrier layer may be formed on any of the layers. The material constituting the barrier layer is, for example, aluminum, steel plate, or stainless steel.

[0129] Figure 27 is a front view of a cover 600, another modified example of the cover 400 in the second embodiment described above. The cover 600 includes a metal portion 610, which is a part where metal is exposed on the surface, and the metal portion 610 and the electrode 210 of the electrode body 200 are welded together. The cover 600 may be composed entirely of the metal portion 610, or the metal portion 610 may be partially formed. When the metal portion 610 is partially formed, the cover 600 is made of a multilayer material including a metal layer. When the cover 600 is made of a multilayer material with a metal layer as an intermediate layer, the metal portion 610 is a part in which layers other than the metal layer have been partially removed so that the metal layer is exposed. In the example shown in Figure 27, the metal portion 610 of the cover 600 functions as an electrode terminal, so no space is required between the cover 600 and the electrode 210. For this reason, the energy storage device 10X (see Figure 9) can be made smaller.

[0130] Figure 28 is a front view of a cover 700, another modified example of the cover 400 in the second embodiment described above. The cover 700 includes a metal part 710 made of a metal material, and a non-metallic part 720 made of a resin material that is connected to the metal part 710. The metal part 710 is welded to the electrode 210 of the electrode body 200. In the example shown in Figure 28, the metal part 710 of the cover 700 functions as an electrode terminal, so no space is required between the cover 700 and the electrode 210. Therefore, the energy storage device 10X (see Figure 9) can be made smaller.

[0131] <5-7> In the above embodiment 1, the second sealing portion 120 was formed by folding the exterior member 101 and heat-sealing the heat-fusible resin layers of the exterior member 101. However, the method of forming the second sealing portion 120 is not limited to this. Figure 29 is a schematic plan view showing a modified second sealing portion 120Y of an energy storage device 10. The exterior member 101 has an overhang portion 101XA that extends outward from the exterior body 100, and the second sealing portion 120Y is formed by heat-sealing the heat-fusible resin layers 101C of the overhang portion 101XA. In the portion of the overhang portion 101XA where the electrode terminals 300 are arranged, the heat-fusible resin layer 101C of the overhang portion 101XA and the electrode terminals 300 are heat-sealed. According to this modified example, the second sealing portion 120Y can be heat-sealed more firmly, thereby improving the airtightness of the exterior body 100. In this modified example, the portion of the protruding part 101XA other than the part heat-sealed to the electrode terminal 300 may be cut off as needed. This modified example can also be applied to the modified example shown in Figure 22.

[0132] <5-8> In the above embodiment 1, the shape of the exterior body 100 can be arbitrarily changed. As shown in Figure 30A, the exterior body 100 may be composed of at least a first exterior member 101AX and a second exterior member 101BX. The specifications of the first exterior member 101AX and the second exterior member 101BX are the same as those of the exterior member 101. At least one of the first exterior member 101AX and the second exterior member 101BX has a recess 101AY for accommodating the electrode body 200. In the example shown in Figure 30A, the recess 101AY is formed in the first exterior member 101AX by, for example, cold forming. The recess 101BY is formed in the second exterior member 101BX by, for example, cold forming. One of the first exterior member 101AX and the second exterior member 101BX may be a sheet in which no recess is formed.

[0133] As shown in Figure 30B, the first exterior member 101AX and the second exterior member 101BX may be parts separated by folding a single exterior member. In the example shown in Figure 30B, the first exterior member 101AX may have a recess 101AY for accommodating the electrode body 200. As shown in Figure 30C, the peripheral edge of the first exterior member 101AX and the peripheral edge of the second exterior member 101BX, which is folded back relative to the first exterior member 101AX, may be joined together at the edges other than the folded edge to form a peripheral seal portion 100AR. As shown in Figure 30D, at least a part of the peripheral seal portion 100AR may be folded back along the electrode body 200.

[0134] Examples of the outer casing 100 having a recess include the examples shown in Figures 30A, 30C, and 30D, as well as the so-called folding tray disclosed in Japanese Patent Application Publication No. 2019-102332 and Japanese Patent Application Publication No. 2019-102333.

[0135] In addition to the examples shown in Figures 30A, 30C, and 30D, the outer packaging 100 may be a brick-type pouch (see Figure 29), a bell-top type pouch, a standing type pouch, a gusset type pouch, a three-sided sealed pouch, a four-sided sealed pouch, or pillow packaging.

[0136] <5-9> In the above embodiment 1, the method for forming the first sealing portion 110 can be arbitrarily selected. As shown in Figure 31, for example, the manufacturing apparatus may form the first sealing portion 110 in step S120 (see Figure 8) by pressing the seal bar 800 at a position away from the base 135X of the portion 110Y of the outer casing 100 in which the first sealing portion 110 is to be formed. According to this manufacturing method, as shown in Figure 32, the first sealing portion 110 has a recess 110X formed, which is the trace left by the seal bar 800 being pressed. In the portion of the outer casing 100 in which the recess 110X is formed, the opposing surfaces (heat-fusible resin layers) of the outer casing member 101 are directly joined together. Between the recess 110X and the base 135X of the outer casing 100, a poly reservoir 900 is formed between the opposing surfaces of the outer casing member 101, where a portion of the resin constituting the outer casing member 101 has melted. In the portion of the exterior body 100 between the recess 110X and the base 135X, the opposing surfaces (heat-fusible resin layers) of the exterior member 101 are joined together via the poly reservoir 900. That is, in this modified example, the first sealing portion 110 includes a portion where the opposing surfaces of the exterior member 101 are directly joined together, and a portion where the opposing surfaces of the exterior member 101 are joined together via the poly reservoir 900. Since the poly reservoir 900 prevents water vapor and the like from entering the interior of the exterior body 100 from the outside, the barrier properties of the exterior body 100 are enhanced. When pressing the seal bar 800 against portion 110Y, it is necessary that the opposing surfaces of the exterior member 101 in the portion where the poly reservoir 900 is formed, in other words, in the portion between the recess 110X and the base 135X, are in contact with each other.

[0137] The distance X between the base 135X and the edge 810 of the seal bar 800 in the LR direction, in other words, the distance between the base 135X and the recess 110X in the LR direction, can be arbitrarily selected. From the viewpoint of forming a wider poly reservoir 900, the distance X is preferably, for example, 1 mm or more, more preferably 1.5 mm or more, and even more preferably 1.7 mm or more. From the viewpoint of forming the first sealing portion 110 compactly, the distance X is preferably, for example, 10 mm or less, more preferably 5 mm or less, and even more preferably 3 mm or less. Preferred ranges for the distance X include, for example, approximately 1 mm to 10 mm, approximately 1 mm to 5 mm, approximately 1 mm to 3 mm, approximately 1.5 mm to 10 mm, approximately 1.5 mm to 5 mm, approximately 1.5 mm to 3 mm, approximately 1.7 mm to 10 mm, approximately 1.7 mm to 5 mm, and approximately 1.7 mm to 3 mm. The distance X is most preferably 2 mm, for example. Alternatively, the distance X may be substantially 0. When the distance X is substantially 0, the seal bar 800 is pressed against the exterior body 100 such that the base 135X and the edge 810 of the seal bar 800 substantially coincide. "Substantially coincide" includes cases where the base 135X and the edge 810 of the seal bar 800 perfectly coincide, as well as cases where the positions of the base 135X and the edge 810 of the seal bar 800 are slightly misaligned due to manufacturing errors, etc. Therefore, a distance X of substantially 0 also includes cases where the distance X is less than 1 mm, for example. These variations can also be applied to embodiments 2 to 4. Note that depending on the shape of the portion of the recess 110X corresponding to the edge 810 of the seal bar 800, the distance between the base 135X and the recess 110X may not be constant. In such cases, the distance X may be the distance between the center of the recess 110X and the center of the base 135X in the FB direction. In another example, distance X may be calculated based on the average of several values, including the maximum and minimum distances between the base 135X and the recess 110X. Similarly, depending on the shape of the base 135X, the distance between the base 135X and the recess 110X may not be constant. In such cases, distance X may be the distance between the center of the base 135X and the center of the recess 110X in the FB direction.In another example, the distance X may be calculated based on the average of several values, including the maximum and minimum distances between the recess 110X and the base 135X.

[0138] In the above embodiment 2, as shown in Figure 33, the outer casing 100X may include a barrier film 91 that suppresses the permeation of the electrolyte. Preferably, the barrier film 91 is placed at least between the inner surface of the outer casing member 101X and the electrode body 200. Preferably, the barrier film 91 is bonded to the inner surface of the outer casing member 101X. Preferably, the barrier film 91 is made of a material that can permeate gas generated inside the outer casing 100X. The material constituting the barrier film 91 is, for example, a resin film or a porous film. Because the outer casing 100X has a barrier film 91, deterioration of the outer casing member 101X due to the electrolyte can be suppressed.

[0139] In the above embodiment 1, as shown in Figure 34, the outer casing 100 may include a cushioning film 92 to increase the strength of the outer casing member 101. It is preferable that the cushioning film 92 be placed on at least the corner portion 100Z of the outer casing 100 on the inner surface of the outer casing member 101. Because the outer casing 100 includes the cushioning film 92, the occurrence of pinholes in the outer casing 100 can be suppressed. The material constituting the cushioning film 92 is, for example, a polyester-based material, a polyolefin-based material, or a fluorine-based material. In this modified example, as shown in Figure 33, a second sealing portion 120 may be formed by joining the inner surface of the outer casing member 101 and the electrode terminal 300. It is preferable that the space 93 between the second sealing portion 120 and the electrode body 200 is filled with an electrolyte.

[0140] In the first embodiment described above, an adhesive film that adheres to both metal and resin may be placed between the electrode terminal 300 and the exterior member 101. In other embodiments, an adhesive film may also be placed in a similar manner.

[0141] In the above-described embodiment 2, an adhesive film that adheres to both metal and resin, similar to that in embodiment 1, may be placed between the lid 400 and the electrode terminal 300. In other embodiments, an adhesive film may be placed in the same manner.

[0142] [6. Examples] The inventors of the present invention conducted the first, second, third, and fourth tests on the exterior members for energy storage devices of the examples and reference examples. For the sake of convenience of explanation, in the following description, elements that constitute the exterior members for energy storage devices of the examples and reference examples that are the same as those in the embodiments will be denoted by the same reference numerals as in the embodiments.

[0143] <6-1. First Test> The first test is to confirm the limit forming depth when cold forming is performed on the exterior members 101 of Examples 1 to 10 and Reference Examples 1 to 4. In the first test, cold forming was performed on the exterior members 101 of Examples 1 to 10 and Reference Examples 1 to 4. The depth to which a pinhole appeared in the exterior member 101 was defined as the limit forming depth.

[0144] The exterior member 101 of Examples 1 to 10 has a layer structure consisting of a PET film layer / adhesive / ONY film layer / adhesive / aluminum layer (barrier layer 101B) / acid-modified polypropylene layer / polypropylene layer in that order from the outside. The PET film layer / adhesive / ONY film layer corresponds to the base layer 101A. The acid-modified polypropylene layer / polypropylene layer corresponds to the heat-fusible resin layer 101C.

[0145] The thickness of the PET film layer is 12 μm. The thickness of the ONY film layer is 15 μm. The thickness of the aluminum layer is 40 μm. The thickness of the acid-modified polypropylene layer is 40 μm. The thickness of the polypropylene layer is 40 μm.

[0146] The material constituting the barrier layer 101B of Example 1 contains 100% by mass of recycled aluminum alloy of alloy number 1050A.

[0147] The material constituting the barrier layer 101B of Example 2 contains 100% by mass of recycled aluminum alloy of alloy number 3004.

[0148] The material constituting the barrier layer 101B of Example 3 contains 100% by mass of recycled aluminum alloy of alloy number 5052.

[0149] The material constituting the barrier layer 101B of Example 4 contains 55% by mass of recycled aluminum alloy of alloy number 1050A and 45% by mass of virgin aluminum alloy of alloy number 1050A.

[0150] The material constituting the barrier layer 101B of Example 5 contains 55% by mass of recycled aluminum alloy of alloy number 3004 and 45% by mass of virgin aluminum alloy of alloy number 3004.

[0151] The material constituting the barrier layer 101B of Example 6 contains 55% by mass of recycled aluminum alloy of alloy number 5052 and 45% by mass of virgin aluminum alloy of alloy number 5052.

[0152] The material constituting the barrier layer 101B of Example 7 contains 55% by mass of recycled aluminum alloy of alloy number 3004 and 45% by mass of virgin aluminum alloy of alloy number 1050A.

[0153] The material constituting the barrier layer 101B of Example 8 contains 55% by mass of recycled aluminum alloy of alloy number 1050A and 45% by mass of virgin aluminum alloy of alloy number 3004.

[0154] The material constituting the barrier layer 101B of Example 9 contains 55% by mass of recycled aluminum alloy alloy of alloy number 5052 and 45% by mass of virgin aluminum alloy alloy of alloy number 1050A.

[0155] The material constituting the barrier layer 101B in Example 10 contains 55% by mass of recycled aluminum alloy of alloy number 1050A and 45% by mass of virgin aluminum alloy of alloy number 5052. The size of the exterior member 101 in Examples 1 to 10 is MD 90 mm × TD 150 mm.

[0156] The composition of the recycled aluminum alloy alloy of alloy number 1050A used in the barrier layer 101B of Examples 1, 4, 8, and 10 is as follows: Si: 0.090 mass% Fe: 0.150 mass% Cu: 0.045 mass% Mn: 0.005 mass% Mg: 0.040 mass% Inevitable impurities: 0.005 mass%

[0157] The composition of the recycled aluminum alloy alloy of alloy number 3004 used in the barrier layer 101B of Examples 2, 5, and 7 is as follows: Si: 0.050 mass% Fe: 0.450 mass% Cu: 0.080 mass% Mn: 1.30 mass% Mg: 1.00 mass% Cr: 0.001 mass% Zn: 0.045 mass% Inevitable impurities: 0.030 mass%

[0158] The composition of the recycled aluminum alloy alloy of alloy number 5052 used in the barrier layer 101B of Examples 3, 6, and 9 is as follows: Si: 0.150 mass% Fe: 0.230 mass% Cu: 0.025 mass% Mn: 0.015 mass% Mg: 2.55 mass% Cr: 0.250 mass% Zn: 0.030 mass% Unavoidable impurities: 0.025 mass%

[0159] The specifications for the exterior member 101 of Reference Example 1 are the same as those for the exterior member 101 of Example 1, except that the materials constituting the barrier layer 101B are all virgin aluminum alloy of alloy number 8021A.

[0160] The composition of the virgin aluminum alloy alloy with alloy number 8021A used in the barrier layer 101B of Reference Example 1 is as follows: Si: 0.130 mass% Fe: 1.50 mass% Cu: 0.015 mass% Mn: 0.004 mass% Mg: 0.001 mass% Inevitable impurities: 0.040 mass%

[0161] The specifications for the exterior member 101 in Reference Example 2 are the same as those for the exterior member 101 in Example 1, except that the materials constituting the barrier layer 101B are all virgin aluminum alloy of alloy number 1050A.

[0162] The composition of the virgin aluminum alloy alloy with alloy number 1050A used in the barrier layer 101B of Reference Example 2 is as follows: Si: 0.070 mass% Fe: 0.120 mass% Cu: 0.025 mass% Mn: 0.005 mass% Mg: 0.020 mass% Inevitable impurities: 0.005 mass%

[0163] The specifications for the exterior member 101 in Reference Example 3 are the same as those for the exterior member 101 in Example 1, except that the materials constituting the barrier layer 101B are all virgin aluminum alloy of alloy number 3004. The composition of the virgin aluminum alloy of alloy number 3004 used in the barrier layer 101B of Reference Example 3 is as follows: Si: 0.040 mass% Fe: 0.400 mass% Cu: 0.060 mass% Mn: 1.25 mass% Mg: 1.00 mass% Cr: 0.001 mass% Zn: 0.040 mass% Inevitable impurities: 0.030 mass%

[0164] The specifications for the exterior member 101 in Reference Example 4 are the same as those for the exterior member 101 in Example 1, except that the materials constituting the barrier layer 101B are all virgin aluminum alloy of alloy number 5052.

[0165] The composition of the virgin aluminum alloy alloy with alloy number 5052 used in the barrier layer 101B of Reference Example 3 is as follows: Si: 0.130 mass% Fe: 0.210 mass% Cu: 0.020 mass% Mn: 0.015 mass% Mg: 2.45 mass% Cr: 0.230 mass% Zn: 0.030 mass% Inevitable impurities: 0.025 mass%

[0166] The limit molding depth of the exterior member 101 in Example 1 was 3.4 mm. The limit molding depth of the exterior member 101 in Example 2 was 2.7 mm. The limit molding depth of the exterior member 101 in Example 3 was 2.2 mm. The limit molding depth of the exterior member 101 in Example 4 was 3.2 mm. The limit molding depth of the exterior member 101 in Example 5 was 2.6 mm. The limit molding depth of the exterior member 101 in Example 6 was 2.1 mm. The limit molding depth of the exterior member 101 in Example 7 was 2.7 mm. The limit molding depth of the exterior member 101 in Example 8 was 2.6 mm. The limit molding depth of the exterior member 101 in Example 9 was 2.1 mm. The limit molding depth of the exterior member 101 in Example 10 was 2.2 mm. The limit molding depth of the exterior member 101 in Reference Example 1 was 6.4 mm. The limit molding depth of the exterior member 101 in Reference Example 2 was 3.5 mm. The limit molding depth of the exterior member 101 in Reference Example 3 was 2.7 mm. The limit molding depth of the exterior member 101 in Reference Example 4 was 2.3 mm.

[0167] In the first test, it was confirmed that a certain degree of cold forming depth could be obtained even when the material constituting the barrier layer 101B of the exterior member 101 was entirely recycled aluminum alloy of alloy number 1050A, recycled aluminum alloy of alloy number 3004, or recycled aluminum alloy of alloy number 5052, at a rate of 50% by mass or more.

[0168] <6-2. Second Test> The second test is to confirm the wrapability of the exterior member 101 of Examples 11 to 20 and Reference Examples 5 to 8 when wrapped around the simulated electrode body and the lid 400.

[0169] The specifications of the exterior member 101 in Example 11 are the same as those of the exterior member 101 in Example 1, except that the size is MD 360 mm × TD 160 mm.

[0170] The specifications of the exterior member 101 in Example 12 are the same as those of the exterior member 101 in Example 2, except that the size is MD 360 mm × TD 160 mm.

[0171] The specifications of the exterior member 101 in Example 13 are the same as those of the exterior member 101 in Example 3, except that the size is MD 360 mm × TD 160 mm.

[0172] The specifications of the exterior member 101 in Example 14 are the same as those of the exterior member 101 in Example 4, except that the size is MD 360 mm × TD 160 mm.

[0173] The specifications of the exterior member 101 in Example 15 are the same as those of the exterior member 101 in Example 5, except that the size is MD 360 mm × TD 160 mm.

[0174] The specifications of the exterior member 101 in Example 16 are the same as those of the exterior member 101 in Example 6, except that the size is MD 360 mm × TD 160 mm.

[0175] The specifications of the exterior member 101 in Example 17 are the same as those of the exterior member 101 in Example 7, except that the size is MD 360 mm × TD 160 mm.

[0176] The specifications of the exterior member 101 in Example 18 are the same as those of the exterior member 101 in Example 8, except that the size is MD 360 mm × TD 160 mm.

[0177] The specifications of the exterior member 101 in Example 19 are the same as those of the exterior member 101 in Example 9, except that the size is MD 360 mm × TD 160 mm.

[0178] The specifications of the exterior member 101 in Example 20 are the same as those of the exterior member 101 in Example 10, except that the size is MD 360 mm × TD 160 mm.

[0179] The specifications for the exterior member 101 in Reference Example 5 are the same as those for the exterior member 101 in Reference Example 1, except that the size is MD360mm x TD160mm.

[0180] The specifications for the exterior member 101 in Reference Example 6 are the same as those for the exterior member 101 in Reference Example 2, except that the size is MD 360 mm x TD 160 mm.

[0181] The specifications for the exterior member 101 in Reference Example 7 are the same as those for the exterior member 101 in Reference Example 3, except that the size is MD360mm x TD160mm.

[0182] The specifications for the exterior member 101 in Reference Example 8 are the same as those for the exterior member 101 in Reference Example 4, except that the size is MD360mm x TD160mm.

[0183] The lid 400 used in the second test is made of polypropylene and is rectangular in shape. The dimensions of the lid 400 are 100 mm in length in the LR direction, 30 mm in width in the UD direction, and 5 mm in thickness in the FB direction. The simulated electrode is made of aluminum and is rectangular in shape. The dimensions of the simulated electrode are 140 mm in length in the FB direction, 98 mm in width in the LR direction, and 28 mm in thickness in the UD direction.

[0184] In the second test, lids 400 were placed on both sides of the length of the simulated electrode body, and this was wrapped with the exterior member 101 of Examples 4 to 6 or Reference Example 2 to form the first sealing portion 110 and the second sealing portion 120X, thereby obtaining a simulated energy storage device. The simulated energy storage device does not have electrode terminals. The seal width of the first sealing portion 110 is 10 mm. The seal width of the second sealing portion 120X is 5 mm, the same as the thickness of the lid 400. The heat sealing conditions for the second sealing portion 120X were a temperature of 180°C, a surface pressure of 0.15 MPa, and a time of 3 seconds. The heat sealing conditions were set so that the ratio of (thickness of the heat-fusible resin layer 101C at the location where the heat-fusible resin layer 101C is heat-fusibly bonded to the lid 400) / (thickness of the heat-fusible resin layer 101C at the location where the heat-fusible resin layer 101C is not heat-fusibly bonded to the lid 400) was between 20% and 80%. This ratio of 20% to 80% can be adjusted by setting the heat sealing temperature to approximately 160 to 240°C, the surface pressure to approximately 0.2 to 1.5 MPa, and the heat sealing time to approximately 1 to 12 seconds.

[0185] Visual inspection confirmed that the exterior members 101 of Examples 11 to 20 and the exterior members 101 of Reference Examples 5 to 8 could be wrapped around the simulated electrode body and lid 400 with little difference in wrinkles and slack. Therefore, it was confirmed that even when 50% by mass or more of recycled 1000 series aluminum alloy, recycled 3000 series aluminum alloy, or recycled 5000 series aluminum alloy is used as the material constituting the barrier layer 101B of the exterior member 101, the same level of wrapability around the simulated electrode body and lid 400 as when all virgin material is used as the material constituting the barrier layer 101B of the exterior member 101 can be obtained.

[0186] <6-3. Third Test> The third test is a test to confirm the corrosion resistance to electrolyte of the barrier layer 101B (aluminum alloy foil) of the exterior member 101 of Examples 21 to 30, Comparative Example 1, and Reference Examples 9 to 11.

[0187] The material constituting the barrier layer 101B of Example 21 contains 100% by mass of recycled aluminum alloy of alloy number 1050A. The composition of the recycled aluminum alloy of alloy number 1050A is as described in the first test.

[0188] The material constituting the barrier layer 101B of Example 22 contains 100% by mass of recycled aluminum alloy of alloy number 3004. The composition of the recycled aluminum alloy of alloy number 3004 is as described in Test 1.

[0189] The material constituting the barrier layer 101B of Example 23 contains 100% by mass of recycled aluminum alloy of alloy number 5052. The composition of the recycled aluminum alloy of alloy number 5052 is as described in the first test.

[0190] The barrier layer 101B of Example 24 consists of 55% by mass of recycled aluminum alloy of alloy number 1050A and 45% by mass of virgin aluminum alloy of alloy number 1050A. The composition of the recycled aluminum alloy of alloy number 1050A is as described in the first test.

[0191] The barrier layer 101B of Example 25 consists of 55% by mass of recycled aluminum alloy of alloy number 3004 and 45% by mass of virgin aluminum alloy of alloy number 3004. The composition of the recycled aluminum alloy of alloy number 3004 is as described in Test 1.

[0192] The barrier layer 101B of Example 26 consists of 55% by mass of recycled aluminum alloy alloy number 5052 and 45% by mass of virgin aluminum alloy alloy number 5052. The composition of the recycled aluminum alloy alloy alloy number 5052 is as described in the first test.

[0193] The barrier layer 101B of Example 27 consists of 55% by mass of recycled aluminum alloy alloy number 3004 and 45% by mass of virgin aluminum alloy alloy number 1050A. The composition of the recycled aluminum alloy alloy alloy number 3004 is as described in the first test.

[0194] The barrier layer 101B of Example 28 consists of 55% by mass of recycled aluminum alloy of alloy number 1050A and 45% by mass of virgin aluminum alloy of alloy number 3004. The composition of the recycled aluminum alloy of alloy number 1050A is as described in the first test.

[0195] The barrier layer 101B of Example 29 consists of 55% by mass of recycled aluminum alloy alloy number 5052 and 45% by mass of virgin aluminum alloy alloy number 1050A. The composition of the recycled aluminum alloy alloy alloy number 5052 is as described in the first test.

[0196] The barrier layer 101B of Example 30 consists of 55% by mass of recycled aluminum alloy alloy number 1050A and 45% by mass of virgin aluminum alloy alloy number 5052. The composition of the recycled aluminum alloy alloy alloy number 1050A is as described in the first test.

[0197] The material constituting the barrier layer 101B of Comparative Example 1 contains 100% by mass of recycled aluminum alloy of alloy number 2024A.

[0198] The composition of the recycled aluminum alloy alloy with alloy number 2024A used in the barrier layer 101B of Comparative Example 1 is as follows: Si: 0.250 mass% Fe: 0.210 mass% Cu: 4.30 mass% Mn: 0.550 mass% Mg: 1.35 mass% Cr: 0.030 mass% Zn: 0.020 mass% Ti: 0.110 mass% Unavoidable impurities: 0.025 mass%

[0199] The material constituting the barrier layer 101B in Reference Example 9 contains 100% by mass of virgin aluminum alloy of alloy number 1050A. The composition of the virgin aluminum alloy of alloy number 1050A is as described in the first test.

[0200] The material constituting the barrier layer 101B in Reference Example 10 contains 100% by mass of virgin aluminum alloy of alloy number 3004. The composition of the virgin aluminum alloy of alloy number 3004 is as described in the first test.

[0201] The material constituting the barrier layer 101B of Reference Example 11 contains 100% by mass of virgin aluminum alloy of alloy number 5052. The composition of the virgin aluminum alloy of alloy number 5052 is as described in the first test.

[0202] In the third test, the aluminum alloy foils of Examples 21-30, Comparative Example 1, and Reference Examples 9-11 were cut into rectangles measuring 45 mm in length and 15 mm in width. Next, rectangular polyethylene films measuring 50 mm in length and 20 mm in width were heat-sealed and attached to the front and back surfaces of each aluminum alloy foil, so that a 1 cm diameter exposed area was formed on one side of the front and back surfaces of each foil, to create the test samples. The corrosion resistance of the test samples was evaluated on the 1 cm diameter exposed portion of the aluminum alloy foil, while the ends of the test samples that were not immersed in the electrolyte were left exposed for connection to the working electrode. Next, the aluminum alloy of the test sample was set as the working electrode, and metallic lithium (disc-shaped, 15 mm in diameter and 0.35 mm thick) was set as the counter electrode, and both were immersed in the electrolyte. The electrolyte consisted of 1 mol / l LiPF6 and a mixture of ethylene carbonate, diethyl carbonate, and dimethyl carbonate (volume ratio 1:1:1). In this state, a voltage of 0.1 V was applied for 10 hours at 20°C, and then the surface of the aluminum alloy foil was observed.

[0203] In Examples 21-30 and Reference Examples 9-11, no changes were observed on the surface of the barrier layer 101B; in other words, no corrosion was observed on the surface. In Comparative Example 1, corrosion was observed on the surface of the barrier layer 101B. Specifically, in Comparative Example 1, a compound of aluminum alloy and lithium was formed on the corroded aluminum alloy foil surface, and it was observed that the surface was raised due to volume expansion.

[0204] <6-4. Test 4> Test 4 is a test to confirm the corrosion resistance of the barrier layer 101B (aluminum alloy foil) of the exterior member 101 of Examples 31 to 40, Comparative Example 2, and Reference Examples 12 to 14 to all solid electrolytes.

[0205] The specifications of the material constituting the barrier layer 101B in Example 31 are the same as those of the material constituting the barrier layer 101B in Example 21.

[0206] The specifications of the material constituting the barrier layer 101B in Example 32 are the same as those of the material constituting the barrier layer 101B in Example 22.

[0207] The specifications of the material constituting the barrier layer 101B in Example 33 are the same as those of the material constituting the barrier layer 101B in Example 23.

[0208] The specifications of the material constituting the barrier layer 101B in Example 34 are the same as those of the material constituting the barrier layer 101B in Example 24.

[0209] The specifications of the material constituting the barrier layer 101B in Example 35 are the same as those of the material constituting the barrier layer 101B in Example 25.

[0210] The specifications of the material constituting the barrier layer 101B in Example 36 are the same as those of the material constituting the barrier layer 101B in Example 26.

[0211] The specifications of the material constituting the barrier layer 101B in Example 37 are the same as those of the material constituting the barrier layer 101B in Example 27.

[0212] The specifications of the material constituting the barrier layer 101B in Example 38 are the same as those of the material constituting the barrier layer 101B in Example 28.

[0213] The specifications of the material constituting the barrier layer 101B in Example 39 are the same as those of the material constituting the barrier layer 101B in Example 29.

[0214] The specifications of the material constituting the barrier layer 101B in Example 40 are the same as those of the material constituting the barrier layer 101B in Example 30.

[0215] The specifications of the material constituting the barrier layer 101B in Comparative Example 2 are the same as those of the material constituting the barrier layer 101B in Comparative Example 1.

[0216] The specifications for the material constituting the barrier layer 101B in Reference Example 12 are the same as the specifications for the material constituting the barrier layer 101B in Reference Example 9.

[0217] The specifications of the material constituting the barrier layer 101B in Reference Example 13 are the same as the specifications of the material constituting the barrier layer 101B in Reference Example 10.

[0218] The specifications for the material constituting the barrier layer 101B in Reference Example 14 are the same as the specifications for the material constituting the barrier layer 101B in Reference Example 11.

[0219] In the fourth test, a solid electrolyte (Li2S-P2S5 (75:25)) with a thickness of 800 μm and a diameter of 10 mm was prepared in a glove box by compaction molding. Next, a first indium foil (thickness 0.3 mm, diameter 9 mm), a lithium foil (thickness 0.2 mm, diameter 8 mm), and a second indium foil (thickness 0.1 mm, diameter 9 mm) were placed on top of the solid electrolyte with the second indium foil facing the solid electrolyte side, and the assembly was restrained and left overnight. After that, the restraints were released, and aluminum alloy foils constituting the barrier layer 101B of Examples 31-40, Comparative Example 2, and Reference Examples 12-14 were punched out to a diameter of 9 mm and laminated onto the solid electrolyte on the opposite side of the foils. The resulting laminate was restrained and sealed in a leaded glass cell. The laminate was removed from the glove box and left for 1 hour to stabilize. In this state, a voltage of -0.53 V was applied for 3 hours at 25°C, and the amount of electricity per unit area was calculated. Electrical charge is 4 C / cm 2 If the value is less than 4 C / cm, it is considered no corrosion. 2 Corrosion was determined to be present if the above conditions were met.

[0220] The barrier layer 101B in Examples 31-40 and Reference Examples 12-14 showed no corrosion. The barrier layer 101B in Comparative Example 2 showed corrosion.

[0221] 10, 10X, 10XA, 10Y, 10Z: Energy storage device 100, 100X, 100Y: Outer casing 101, 101Y, 101Z1, 101Z2: Outer casing member 101A: Base layer 101B: Barrier layer 101C: Heat-sealable resin layer 101AX: First outer casing member 101BX: Second outer casing member 101AY: Recess 110, 110Z, 154: First sealing part 120, 120X, 120Y: Second sealing part 200: Electrode body

Claims

It is composed of a laminate comprising, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer. The barrier layer contains 50% by mass or more of recycled aluminum alloy material. The recycled aluminum alloy material is either recycled 1000 series aluminum alloy, recycled 3000 series aluminum alloy, or recycled 5000 series aluminum alloy. Exterior components for energy storage devices. 　 The recycled aluminum alloy material contained in the barrier layer is less than 100% by mass. If the recycled aluminum alloy is a recycled 1000 series aluminum alloy, the remaining aluminum alloy contained in the barrier layer is virgin 3000 series aluminum alloy or virgin 5000 series aluminum alloy. If the recycled aluminum alloy material is a recycled 3000 series aluminum alloy, the remaining aluminum alloy contained in the barrier layer is a virgin 1000 series aluminum alloy. If the recycled aluminum alloy is a recycled 5000 series aluminum alloy, the remaining aluminum alloy contained in the barrier layer is a virgin 1000 series aluminum alloy. The exterior member according to claim 1. 　 It is composed of a laminate comprising, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer. The barrier layer contains 50% by mass or more of recycled aluminum alloy material. The recycled aluminum alloy material is Si: 0.25% by mass or less, Fe: 0.40% by mass or less, Cu: 0.20% by mass or less, Mn: 0.05% by mass or less, Mg: 0.10% by mass or less, The composition satisfies the requirement that unavoidable impurities are 0.15% by mass or less. Exterior components for energy storage devices. 　 It is composed of a laminate comprising, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer. The barrier layer contains 50% by mass or more of recycled aluminum alloy material. The recycled aluminum alloy material is Si: 0.60% by mass or less, Fe: 0.80% by mass or less, Cu: 0.30% by mass or less, Mn: 0.30 mass% or more, 1.50 mass% or less, Mg: 1.30% by mass or less, Cr: 0.20% by mass or less, Zn: 0.40% by mass or less, and The composition satisfies the requirement that unavoidable impurities are 0.15% by mass or less. Exterior components for energy storage devices. 　 It is composed of a laminate comprising, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer. The barrier layer contains 50% by mass or more of recycled aluminum alloy material. The recycled aluminum alloy material is Si: 0.40% by mass or less, Fe: 0.70% by mass or less, Cu: 0.20% by mass or less, Mn: 1.00% by mass or less, Mg: 0.20% by mass or more, 5.50% by mass or less, Cr: 0.50% by mass or less, Zn: 0.25% by mass or less, and The composition satisfies the requirement that unavoidable impurities are 0.15% by mass or less. Exterior components for energy storage devices. 　 A method for manufacturing an exterior member for an energy storage device according to any one of claims 1 to 5, The process includes manufacturing the aforementioned laminate, The barrier layer contains 50% by mass or more of the recycled aluminum alloy material. A method for manufacturing exterior components for energy storage devices. 　 Exterior components for energy storage devices, The electrode body is enclosed by the aforementioned outer casing member for the energy storage device, The aforementioned exterior member for the energy storage device is It is composed of a laminate comprising, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer. The barrier layer contains 50% by mass or more of recycled aluminum alloy material. The aluminum alloy contained in the barrier layer is recycled material of 1000 series aluminum alloy, recycled material of 3000 series aluminum alloy, or recycled material of 5000 series aluminum alloy. Energy storage device. 　 The recycled aluminum alloy material contained in the barrier layer is less than 100% by mass. If the recycled aluminum alloy is a recycled 1000 series aluminum alloy, the remaining aluminum alloy contained in the barrier layer is virgin 3000 series aluminum alloy or virgin 5000 series aluminum alloy. If the recycled aluminum alloy material is a recycled 3000 series aluminum alloy, the remaining aluminum alloy contained in the barrier layer is a virgin 1000 series aluminum alloy. If the recycled aluminum alloy is a recycled 5000 series aluminum alloy, the remaining aluminum alloy contained in the barrier layer is a virgin 1000 series aluminum alloy. The energy storage device according to claim 7. 　 Exterior components for energy storage devices, The electrode body is enclosed by the aforementioned outer casing member for the energy storage device, The aforementioned exterior member for the energy storage device is It is composed of a laminate comprising, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer. The barrier layer contains 50% by mass or more of recycled aluminum alloy material. The recycled aluminum alloy material is Si: 0.25% by mass or less, Fe: 0.40% by mass or less, Cu: 0.20% by mass or less, Mn: 0.05% by mass or less, Mg: 0.10% by mass or less, The composition satisfies the requirement that unavoidable impurities are 0.15% by mass or less. Energy storage device. 　 Exterior components for energy storage devices, The electrode body is enclosed by the aforementioned outer casing member for the energy storage device, The aforementioned exterior member for the energy storage device is It is composed of a laminate comprising, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer. The barrier layer contains 50% by mass or more of recycled aluminum alloy material. The recycled aluminum alloy material is Si: 0.60% by mass or less, Fe: 0.80% by mass or less, Cu: 0.30% by mass or less, Mn: 0.30 mass% or more, 1.50 mass% or less, Mg: 1.30% by mass or less, Cr: 0.20% by mass or less, Zn: 0.40% by mass or less, and The composition satisfies the requirement that unavoidable impurities are 0.15% by mass or less. Energy storage device. 　 Exterior components for energy storage devices, The electrode body is enclosed by the aforementioned outer casing member for the energy storage device, The aforementioned exterior member for the energy storage device is It is composed of a laminate comprising, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer. The barrier layer contains 50% by mass or more of recycled aluminum alloy material. The recycled aluminum alloy material is Si: 0.40% by mass or less, Fe: 0.70% by mass or less, Cu: 0.20% by mass or less, Mn: 1.00% by mass or less, Mg: 0.20% by mass or more, 5.50% by mass or less, Cr: 0.50% by mass or less, Zn: 0.25% by mass or less, and The composition satisfies the requirement that unavoidable impurities are 0.15% by mass or less. Energy storage device. 　 The electrode body is enclosed by the aforementioned exterior member for the energy storage device, and the device includes a first sealing portion which is sealed by joining the opposing surfaces of the exterior member for the energy storage device together. The energy storage device according to any one of claims 7 to 11. 　 A lid that seals the electrode body together with the exterior member for the energy storage device, The lid and the exterior member for the energy storage device are joined together to form a second sealing portion, which further includes The energy storage device according to any one of claims 7 to 11. 　 The exterior member for the energy storage device includes a first exterior member and a second exterior member. At least one of the first exterior member and the second exterior member has a recess formed therein for housing the electrode body. The energy storage device according to any one of claims 7 to 11. 　 A method for manufacturing an energy storage device according to any one of claims 7 to 11, The process includes manufacturing the exterior member for the energy storage device, which is composed of the laminate, The barrier layer contains 50% by mass or more of the recycled aluminum alloy material. A method for manufacturing energy storage devices.

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