Power storage device, lid, and manufacturing method of power storage device

Abstract

To provide a power storage device, a lid, and a manufacturing method of the power storage device in which an electrode body is suitably maintained in a sealed state by an exterior body.SOLUTION: A power storage device 10 includes an electrode body 20 and an exterior body 40 that seals the electrode body 20, and the exterior body 40 includes an exterior film 50 wrapped around the electrode body 20 so as to have an opening, a lid 60 disposed in the opening, a first sealing portion 70 in which surfaces of the exterior film 40 that face each other are sealed, and a second sealing portion 80 in which opposing surfaces of the lid 60 and the exterior film 40 are sealed, and the sealing strength of the second sealing portion 80 is 40 N / 15 mm or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electricity storage device, a lid, and a method for manufacturing an electricity storage device. [Background technology]

[0002] Patent Document 1 discloses an all-solid-state battery as an example of an electricity storage device. This all-solid-state battery includes an electrode body and an exterior body that seals the electrode body. The exterior body includes an exterior film that is wrapped around the electrode body to have an opening, and a lid body that is placed on the opening. The exterior film and the outer peripheral surface of the lid body are heat-sealed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-153504 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an electricity storage device, in order to maintain a state in which the electrode body is sealed by the exterior body, it is preferable that the exterior film and the lid body are firmly bonded to each other. In this respect, there is room for improvement in the above-mentioned all-solid-state battery.

[0005] An object of the present invention is to provide an electricity storage device in which an electrode body is suitably maintained in a sealed state by an exterior body, a lid body used in this electricity storage device, and a method for manufacturing the electricity storage device. [Means for solving the problem]

[0006] The energy storage device according to a first aspect of the present invention comprises an electrode body and an exterior body that seals the electrode body, the exterior body including an exterior film that is wrapped around the electrode body to have an opening, a lid body that is placed on the opening, a first sealing portion in which facing surfaces of the exterior film are sealed together, and a second sealing portion in which facing surfaces of the lid body and the exterior film are sealed together, and the sealing strength of the second sealing portion is 40 N / 15 mm or more.

[0007] An energy storage device according to a second aspect of the present invention comprises an electrode body and an outer casing that seals the electrode body, the outer casing including an outer casing film that is wrapped around the electrode body to have an opening, a lid body that is placed in the opening, a first sealing portion in which facing surfaces of the outer casing film are sealed, and a second sealing portion in which facing surfaces of the lid body and the outer casing film are sealed, the lid body including a first surface facing the electrode body and a second surface opposite to the first surface, an inner poly pool is formed between the first surface and the outer casing film, and an outer poly pool is formed between the second surface and the outer casing film, the length of the inner poly pool being shorter than the length of the outer poly pool.

[0008] An energy storage device according to a third aspect of the present invention comprises an electrode body and an exterior body that seals the electrode body, the exterior body including an exterior film that is wrapped around the electrode body to have an opening, a lid body that is placed in the opening, a first sealing portion in which facing surfaces of the exterior film are sealed, and a second sealing portion in which facing surfaces of the lid body and the exterior film are sealed, the exterior film has a lid winding portion that is sealed to the lid body at the second sealing portion, the lid body has a lid sealing surface that is sealed to the exterior film at the second sealing portion, and the ratio of the length of the lid winding portion to the length of the lid sealing surface is 103% or less.

[0009] An electricity storage device according to a fourth aspect of the present invention is an electricity storage device according to the first or third aspect, wherein the lid body includes a first surface on the electrode body side and a second surface opposite the first surface, an inner poly pool is formed between the first surface and the exterior film, and an outer poly pool is formed between the second surface and the exterior film, the exterior film includes a heat-sealable resin layer sealed to the lid body, and a ratio of a thickness of the inner poly pool to a thickness of the heat-sealable resin layer is 200% or less.

[0010] An electricity accumulation device according to a fifth aspect of the present invention is the electricity accumulation device according to the third aspect, wherein the seal strength of the second sealing portion is 40 N / 15 mm or more.

[0011] An electricity storage device according to a sixth aspect of the present invention is an electricity storage device according to any one of the first to fifth aspects, wherein the exterior film includes a heat-sealable resin layer that is sealed to the lid, and a material constituting the heat-sealable resin layer and a material constituting the lid are primarily the same.

[0012] A seventh aspect of the present invention is an energy storage device according to the third aspect, wherein the cover body includes a first surface on the electrode body side and a second surface opposite the first surface, an inner polymer pool is formed between the first surface and the exterior film, and an outer polymer pool is formed between the second surface and the exterior film, and the length of the inner polymer pool is shorter than the length of the outer polymer pool.

[0013] An eighth aspect of the present invention is an energy storage device according to the third aspect, wherein the lid body includes a first surface on the electrode body side and a second surface opposite the first surface, an inner poly pool is formed between the first surface and the exterior film, and an outer poly pool is formed between the second surface and the exterior film, the exterior film includes a heat-sealable resin layer sealed to the lid body, and a ratio of a thickness of the inner poly pool to a thickness of the heat-sealable resin layer is 200% or less.

[0014] A lid body according to a ninth aspect of the present invention is a lid body used as an exterior body for an electricity storage device, the exterior body including an exterior film that is wrapped around an electrode body so as to have an opening, the lid body including a sealing surface that is positioned at the opening and sealed with the exterior film, the sealing surface having a recess.

[0015] A lid body according to a tenth aspect of the present invention is a lid body used as an exterior body for an electricity storage device, the exterior body including an exterior film that is wrapped around an electrode body so as to have an opening, the lid body including a sealing surface that is positioned at the opening and sealed with the exterior film, the sealing surface having a groove.

[0016] A lid body according to an eleventh aspect of the present invention is a lid body used as an exterior body for an electricity storage device, the exterior body including an exterior film wrapped around an electrode body so as to have an opening, the lid body being disposed in the opening and including a first surface facing the electrode body, a second surface opposite the first surface, and a sealing surface connecting the first surface and the second surface and sealed to the exterior film, the sealing surface including an inclined surface that inclines toward the center of the height of the lid body as it moves from the second surface to the first surface.

[0017] A twelfth aspect of the present invention is an energy storage device comprising a lid body according to any one of the ninth to eleventh aspects, and comprises an electrode body and an exterior body that seals the electrode body, wherein the exterior body includes an exterior film wrapped around the electrode body to have an opening, the lid body that is placed in the opening, a first sealing portion in which facing surfaces of the exterior film are sealed, and a second sealing portion in which facing surfaces of the lid body and the exterior film are sealed.

[0018] A manufacturing method for an electricity storage device according to a thirteenth aspect of the present invention is a manufacturing method for an electricity storage device comprising an electrode body and an exterior body that seals the electrode body, wherein the exterior body includes an exterior film that is wrapped around the electrode body to have an opening, a lid body that is placed in the opening, a first sealing portion in which facing surfaces of the exterior film are sealed, and a second sealing portion in which facing surfaces of the lid body and the exterior film are sealed, the lid body including a first surface on the electrode body side and a second surface opposite to the first surface, and the manufacturing method for the electricity storage device includes a sealing step of forming the second sealing portion using a seal bar, and in the sealing step, the seal bar is inclined so as to be closer to the boundary between the first surface and the exterior film than the boundary between the second surface and the exterior film.

[0019] A manufacturing method for an electricity storage device according to a fourteenth aspect of the present invention is a manufacturing method for an electricity storage device comprising an electrode body and an exterior body that seals the electrode body, wherein the exterior body includes an exterior film that is wrapped around the electrode body to have an opening, a lid body that is placed in the opening, a first sealing portion in which facing surfaces of the exterior film are sealed, and a second sealing portion in which facing surfaces of the lid body and the exterior film are sealed, the lid body including a first surface on the electrode body side and a second surface opposite to the first surface, and the manufacturing method for the electricity storage device includes a sealing step of forming the second sealing portion using a seal bar, and in the sealing step, the sealing temperature of a portion including the boundary between the first surface and the exterior film is made lower than the sealing temperature of a portion including the boundary between the second surface and the exterior film. Effect of the Invention

[0020] According to the electricity storage device, the lid, and the method for manufacturing the electricity storage device of the present invention, the state in which the electrode body is sealed by the exterior body is suitably maintained. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view of an electricity accumulation device according to a first embodiment. [Diagram 2]2 is a cross-sectional view showing a layer structure of an exterior film included in the electricity storage device of FIG. 1. [Diagram 3] FIG. 2 is a diagram showing the exterior film of the power storage device in FIG. 1 in an unfolded state. [Figure 4] 2 is a front view of a lid provided in the electricity storage device of FIG. 1. [Diagram 5] FIG. 5 is a side view of the lid of FIG. 4 . [Figure 6] 4 is a flowchart showing an example of a manufacturing process for the electricity storage device in FIG. [Figure 7] FIG. 11 is a cross-sectional view of an electricity storage device according to a second embodiment, viewed from the side of a second sealing portion. [Figure 8] 8 is a cross-sectional view of the electricity storage device in FIG. 7 as viewed from the electrode body side. [Figure 9] 8 is a view of the electricity storage device in FIG. 7 as viewed from the opposite side of the electrode body. [Figure 10] 8 is a perspective view showing an example of a lid provided in the electricity storage device in FIG. 7. [Figure 11] 8 is a perspective view showing another example of a lid provided in the electricity storage device in FIG. 7. [Figure 12] 8 is a perspective view showing still another example of a lid provided in the electricity storage device in FIG. 7. [Figure 13] 8 is a cross-sectional view showing an example of a sealing step in a manufacturing method of the electricity storage device in FIG. 7. [Figure 14] FIG. 11 is a side view of a lid provided in an electricity accumulation device according to a modified example of the first embodiment. [Figure 15] FIG. 13 is a front view of a lid provided in an electricity accumulation device according to another modified example of the first embodiment. [Figure 16] FIG. 13 is a side view of a lid provided in an electricity accumulation device according to a modified example of the second embodiment. [Figure 17] FIG. 13 is a side view of a lid provided in an electricity accumulation device according to another modified example of the second embodiment. [Figure 18] FIG. 13 is a cross-sectional view of an electricity storage device according to another modified example of the second embodiment, viewed from the side of the second sealing portion. [Figure 19] FIG. 19 is a front view of the lid body to which the adhesive film of FIG. 18 is attached. [Figure 20] Table showing the test results of the first test. [Figure 21] Table showing the test results of the second test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an electricity storage device according to one embodiment of the present invention will be described with reference to the drawings. In this specification, a numerical range indicated by "to" means "not less than" or "not more than." For example, the expression "2 to 15 mm" means 2 mm or more and 15 mm or less.

[0023] [1. First embodiment] <1-1. Configuration of the power storage device> Fig. 1 is a plan view showing a schematic diagram of an electricity storage device 10 of a first embodiment. Fig. 2 is a cross-sectional view showing a layer structure of an exterior film 50 included in the electricity storage device 10 of Fig. 1. Fig. 3 is a view showing the exterior film 50 included in the electricity storage device 10 of Fig. 1 in an unfolded state. Fig. 4 is a front view of a lid body 60 included in the electricity storage device 10 of Fig. 1. Fig. 5 is a side view of the lid body 60 of Fig. 4. In Fig. 1, the direction of arrow UD indicates the thickness direction of the electricity storage device 10, the direction of arrow LR indicates the width direction of the electricity storage device 10, and the direction of arrow FB indicates the depth direction of the electricity storage device 10.

[0024] The power storage device 10 includes an electrode body 20, an electrode terminal 30, and an exterior body 40. The electrode body 20 includes electrodes (positive and negative electrodes) constituting a power storage member such as a lithium ion battery, a capacitor, an all-solid-state battery, a semi-solid battery, a quasi-solid battery, a polymer battery, an all-resin battery, a lead-acid battery, a nickel-metal hydride battery, a nickel-cadmium battery, a nickel-iron battery, a nickel-zinc battery, a silver oxide-zinc battery, a metal-air battery, a polyvalent cation battery, or a capacitor, and a separator. In this embodiment, the shape of the electrode body 20 is an approximately rectangular parallelepiped. Note that the term "approximately rectangular parallelepiped" includes, in addition to a complete rectangular parallelepiped, a solid body that can be regarded as a rectangular parallelepiped by modifying the shape of a part of the outer surface, for example. The shape of the electrode body 20 may be, for example, a cylinder or a polygonal prism.

[0025] In this embodiment, the power storage device 10 includes two electrode terminals 30. The electrode terminals 30 are metal terminals used for inputting and outputting electric power in the electrode body 20. One end of the electrode terminal 30 is electrically connected to an electrode (positive electrode or negative electrode) included in the electrode body 20. The other end of the electrode terminal 30 protrudes outward from an edge of the exterior body 40, for example. Note that the electrode terminal 30 may not protrude from the exterior body 40, for example, as long as it is capable of inputting and outputting electric power to and from the electrode body 20. When the cover body 60 described later is made of, for example, a metal, the cover body 60 may also function as the electrode terminal 30. In this case, the cover body 60 having the function as an electrode terminal may or may not protrude from the exterior body 40.

[0026] The metal material constituting the electrode terminal 30 is, for example, aluminum, nickel, copper, etc. For example, when the electrode body 20 is a lithium ion battery, the electrode terminal 30 connected to the positive electrode is usually made of aluminum, etc., and the electrode terminal 30 connected to the negative electrode is usually made of copper, nickel, etc. The outermost layer of the electrode body 20 does not necessarily have to be an electrode, and may be, for example, a protective tape or a separator.

[0027] The exterior body 40 seals the electrode body 20. The exterior body 40 includes an exterior film 50 and a lid body 60. The exterior film 50 is wrapped around the electrode body 20 so as to have an opening 40A, and the lid body 60 is disposed on the side of the electrode body 20 so as to close the opening 40A.

[0028] For example, there is a method of forming a storage portion (recess) for storing the electrode body 20 in the exterior film 50 through cold forming. However, it is not necessarily easy to form a deep storage portion by such a method. If an attempt is made to form a deep storage portion (recess) by cold forming (for example, a forming depth of 15 mm), pinholes or cracks will occur in the exterior film 50, which is likely to cause a decrease in battery performance. On the other hand, the exterior body 40 seals the electrode body 20 by wrapping the exterior film 50 around the electrode body 20, so that the electrode body 20 can be easily sealed regardless of the thickness of the electrode body 20. In addition, in order to reduce the dead space between the electrode body 20 and the exterior film 50 to improve the volumetric energy density of the power storage device 10, it is preferable that the exterior film 50 is wrapped so as to contact the outer surface of the electrode body 20. In addition, in an all-solid-state battery, it is necessary to apply a high pressure uniformly from the outer surface of the battery to exhibit battery performance, so it is necessary to eliminate the space between the electrode body 20 and the exterior film 50, and therefore it is preferable that the exterior film 50 is wrapped so as to contact the outer surface of the electrode body 20.

[0029] The exterior film 50 is, for example, a laminate (laminate film) having a base layer 51, a barrier layer 52, and a heat-sealable resin layer 53 in this order. Note that the exterior film 50 does not need to include all of these layers, and for example, the barrier layer 52 may not be included. That is, the exterior film 50 may be made of any material that is flexible and easily bendable, and may be made of, for example, a resin film. Note that the exterior film 50 is preferably heat-sealable.

[0030] The base layer 51 included in the exterior film 50 is a layer for imparting heat resistance to the exterior film 50 and suppressing the occurrence of pinholes that may occur during processing or distribution. The base layer 51 is configured to include at least one layer of a stretched polyester resin layer and a stretched polyamide resin layer. For example, the base layer 51 includes at least one layer of a stretched polyester resin layer and a stretched polyamide resin layer, so that the barrier layer 52 can be protected during processing of the exterior film 50 and breakage of the exterior film 50 can be suppressed. In addition, from the viewpoint of increasing the tensile elongation of the exterior film 50, the stretched polyester resin layer is preferably a biaxially stretched polyester resin layer, and the stretched polyamide resin layer is preferably a biaxially stretched polyamide resin layer. Furthermore, in terms of excellent puncture strength or impact strength, the stretched polyester resin layer is more preferably a biaxially stretched polyethylene terephthalate (PET) film, and the stretched polyamide resin layer is more preferably a biaxially stretched nylon (ONy) film. The base layer 51 may be configured to include both a stretched polyester resin layer and a stretched polyamide resin layer. The thickness of the base layer 51 is, for example, preferably 5 to 300 μm, and more preferably 20 to 150 μm, from the viewpoint of film strength.

[0031] The barrier layer 52 is bonded to the base layer 51 via, for example, an adhesive layer 54. The barrier layer 52 included in the exterior film 50 is made of, for example, aluminum foil from the viewpoints of processability such as moisture resistance and extensibility, and cost. The aluminum foil preferably contains iron from the viewpoints of packaging suitability and pinhole resistance when packaging the electrode body 20. The iron content in the aluminum foil is preferably 0.5 to 5.0 mass%, and more preferably 0.7 to 2.0 mass%. When the iron content is 0.5 mass% or more, the exterior film 50 can obtain packaging suitability, excellent pinhole resistance, and extensibility. In addition, when the iron content is 5.0 mass% or less, the exterior film 50 can obtain excellent flexibility. The barrier layer 52 may include a metal foil, a vapor deposition film, and a resin layer having barrier properties. Examples of the metal foil include aluminum alloy, stainless steel, titanium steel, and steel plate.

[0032] From the viewpoints of barrier properties, pinhole resistance, and packaging suitability, the thickness of the barrier layer 52 is, for example, preferably 15 to 100 μm, and more preferably 30 to 80 μm. When the thickness of the barrier layer 52 is 15 μm or more, the exterior film 50 is less likely to break even when stress is applied during packaging processing. When the thickness of the barrier layer 52 is 100 μm or less, the increase in mass of the exterior film 50 can be reduced, and a decrease in the weight energy density of the electricity storage device 10 can be suppressed.

[0033] In addition, when the barrier layer 52 is an aluminum foil, it is preferable that at least the surface opposite to the base layer 51 is provided with a corrosion-resistant film in order to prevent dissolution and corrosion. The barrier layer 52 may be provided with a corrosion-resistant film on both sides. Here, the corrosion-resistant film refers to a thin film that is provided with corrosion resistance (e.g., acid resistance, alkali resistance, etc.) on the barrier layer 52 by performing, for example, hydrothermal conversion treatment such as boehmite treatment, chemical conversion treatment, anodizing treatment, plating treatment such as nickel or chromium, or corrosion prevention treatment by applying a coating agent on the surface of the barrier layer 52. Specifically, the corrosion-resistant film refers to a film that improves the acid resistance of the barrier layer 52 (acid-resistant film), a film that improves the alkali resistance of the barrier layer 52 (alkali-resistant film), etc. The treatment for forming the corrosion-resistant film may be one type, or two or more types may be combined. In addition, not only one layer but also multiple layers may be formed. Furthermore, among these treatments, hydrothermal conversion treatment and anodizing treatment are treatments in which the metal foil surface is dissolved by a treatment agent to form a metal compound with excellent corrosion resistance. Note that these treatments may also be included in the definition of chemical conversion treatment. In addition, when the barrier layer 52 has a corrosion-resistant coating, the corrosion-resistant coating is also included in the barrier layer 52.

[0034] The corrosion-resistant coating prevents delamination between the barrier layer 52 (e.g., aluminum alloy foil) and the base layer 51 during molding of the exterior film 50, prevents dissolution and corrosion of the surface of the barrier layer 52 due to hydrogen fluoride produced by a reaction between an electrolyte and moisture, and in particular prevents dissolution and corrosion of aluminum oxide present on the surface of the barrier layer 52 when the barrier layer 52 is an aluminum alloy foil, and also improves the adhesion (wettability) of the surface of the barrier layer 52, thereby preventing delamination between the base layer 51 and the barrier layer 52 during heat sealing and between the base layer 51 and the barrier layer 52 during molding.

[0035] The heat-sealable resin layer 53 is bonded to the barrier layer 52, for example, via an adhesive layer 55. The heat-sealable resin layer 53 included in the exterior film 50 is a layer that imparts heat-sealing sealability to the exterior film 50. Examples of the heat-sealable resin layer 53 include resin films made of polyester resins such as polyethylene terephthalate resins and polybutylene terephthalate resins, polyolefin resins such as polyethylene resins and polypropylene resins, or acid-modified polyolefin resins obtained by graft-modifying these polyolefin resins with an acid such as maleic anhydride. The thickness of the heat-sealable resin layer 53 is preferably, for example, 20 to 300 μm, and more preferably 40 to 150 μm, in terms of sealability and strength.

[0036] The exterior film 50 preferably has one or more layers having a buffer function (hereinafter referred to as "buffer layer") outside the heat-sealable resin layer 53, more preferably outside the barrier layer 52. The buffer layer may be laminated on the outside of the base material layer 51, or the base material layer 51 may also function as a buffer layer. When the exterior film 50 has multiple buffer layers, the multiple buffer layers may be adjacent to each other, or may be laminated via the base material layer 51, the barrier layer 52, etc.

[0037] The material constituting the buffer layer can be arbitrarily selected from materials having cushioning properties. The material having cushioning properties is, for example, rubber, nonwoven fabric, or foam sheet. The rubber is, for example, natural rubber, fluororubber, or silicone rubber. The rubber hardness is preferably about 20 to 90. The material constituting the nonwoven fabric is preferably a material having excellent heat resistance. When the buffer layer is made of nonwoven fabric, the lower limit of the thickness of the buffer layer is preferably 100 μm, more preferably 200 μm, and more preferably 1000 μm. When the buffer layer is made of nonwoven fabric, the upper limit of the thickness of the buffer layer is preferably 5000 μm, and more preferably 3000 μm. The thickness of the buffer layer is preferably in the range of 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 thickness of the buffer layer is most preferably in the range of 1000 μm to 3000 μm.

[0038] When the buffer layer is made of rubber, the lower limit of the thickness of the buffer layer is preferably 0.5 mm. When the buffer layer is made of rubber, the upper limit of the thickness of the buffer layer is preferably 10 mm, more preferably 5 mm, and more preferably 2 mm. When the buffer layer is made of rubber, the preferred range of the thickness of the buffer layer is 0.5 mm to 10 mm, 0.5 mm to 5 mm, or 0.5 mm to 2 mm.

[0039] When the exterior film 50 has a buffer layer, the buffer layer functions as a cushion, thereby preventing the exterior film 50 from being damaged by impact when the electricity storage device 10 is dropped or by handling during production of the electricity storage device 10.

[0040] The lid body 60 has, for example, a rectangular parallelepiped shape and is made of, for example, a resin material. The lid body 60 may be formed by, for example, cold forming the exterior film 50, or may be a metal molded product. The lid body 60 has a first surface 61, a second surface 62, a third surface 63, a fourth surface 64, a fifth surface 65, and a sixth surface 66. The first surface 61 faces the electrode body 20. The second surface 62 is the surface opposite to the first surface 61. The third surface 63 constitutes the upper surface of the lid body 60. The fourth surface 64 constitutes the lower surface of the lid body 60. The fifth surface 65 and the sixth surface 66 constitute the side surfaces of the lid body 60. The third surface 63, the fourth surface 64, the fifth surface 65, and the sixth surface 66 are lid seal surfaces that are heat-sealed to the heat-fusible resin layer 53 of the exterior film 50. Hereinafter, the third surface 63 to the sixth surface 66 may be collectively referred to as a lid sealing surface 67.

[0041] From the viewpoint of suitable heat sealing between the lid 60 and the exterior film 50, it is preferable that the material constituting the lid 60 and the material constituting the heat-sealable resin layer 53 of the exterior film 50 are mainly made of the same material. In this embodiment, the material constituting the lid 60 and the material constituting the heat-sealable resin layer 53 are mainly made of polypropylene. Note that the main material refers to, for example, a material that accounts for 50% or more of the materials contained in the components.

[0042] In this embodiment, the lid body 60 is formed with a through hole 60X into which the electrode terminal 30 is inserted. The through hole 60X penetrates the first surface 61 and the second surface 62. When the electrode body 20 is stored, the electrode terminal 30 protrudes to the outside of the exterior body 40 through the through hole 60X formed in the lid body 60. A small gap between the through hole 60X of the lid body 60 and the electrode terminal 30 is filled with, for example, resin. Note that, in the electricity storage device 10, the position from which the electrode terminal 30 protrudes to the outside can be arbitrarily selected. For example, the electrode terminal 30 may protrude to the outside from a hole formed in any one of the six surfaces of the exterior body 40. In this case, a small gap between the exterior body 40 and the electrode terminal 30 is filled with, for example, resin. In the electricity storage device 10, the lid body 60 and the electrode terminal 30 are provided as separate bodies, but the lid body 60 and the electrode terminal 30 may be formed integrally. If the electrode terminals 30 do not protrude from the edge of the exterior body 40, the lid body 60 does not need to have the through-holes 60X formed therein.

[0043] In this embodiment, with the exterior film 50 wrapped around the electrode body 20 so as to have an opening 40A, the facing surfaces of the exterior film 50 (heat-fusible resin layer 53) are heat-sealed to form the first sealing portion 70.

[0044] The first sealed portion 70 is formed by heat-sealing a portion including the first edge 50A and a portion including the second edge 50B of the exterior film 50 shown in FIG. 3. The first sealed portion 70 extends in the longitudinal direction of the exterior body 40. The position at which the first sealed portion 70 is formed in the exterior body 40 can be selected arbitrarily. In this embodiment, the root 70X of the first sealed portion 70 is located on the side 43 at the boundary between the first surface 41 and the second surface 42 of the exterior body 40. The first surface 41 has a larger area than the second surface 42. The root 70X of the first sealed portion 70 may be located on any surface of the exterior body 40. In this embodiment, the first sealed portion 70 is folded toward, for example, the second surface 42 of the exterior body 40. The first sealed portion 70 may protrude outward from the electrode body 20 in a plan view, or may be folded toward the first surface 41.

[0045] In this embodiment, the second sealing portion 80 is formed by heat-sealing the heat-sealing resin layer 53 of the exterior film 50 and the lid seal surface 67 of the lid body 60. Hereinafter, the seal strength between the heat-sealing resin layer 53 of the exterior film 50 and the lid seal surface 67 of the lid body 60 may be referred to as the seal strength of the second sealing portion 80. The seal strength of the second sealing portion 80 is the seal strength between the heat-sealing resin layer 53 and the lid body 60 at the long side portion of the lid seal surface 67, that is, the lid seal surface 67 extending in the LR (width) direction in FIG. 1. The seal strength of the second sealing portion 80 is measured based on the distance of the second sealing portion 80 in the FB (depth) direction by pulling the exterior film 50 in the UD (up-down) direction in FIG. 1 relative to the lid body 60. The seal strength of the second sealing portion 80 in the case where the lid body 60 is divided into multiple parts including long sides and short sides is the seal strength at the long side portion of the lid seal surface 67 of the multiple parts.

[0046] From the viewpoint of suitably maintaining the state in which the electrode body 20 is sealed by the exterior body 40, the seal strength of the second sealing portion 80 is preferably 40N / 15mm or more, more preferably 50N / 15mm or more, more preferably 60N / 15mm or more, more preferably 70N / 15mm or more, and more preferably 85N / 15mm or more. When the seal strength of the second sealing portion 80 is 40N / 15mm or more, the state in which the electrode body 20 is sealed by the exterior body 40 is suitably maintained even if the electricity storage device 10 is used for, for example, several years (less than 10 years). When the seal strength of the second sealing portion 80 is 85N / 15mm or more, the state in which the electrode body 20 is sealed by the exterior body 40 is suitably maintained even if the electricity storage device 10 is used for, for example, 10 years or more. The seal strength of the second sealing portion 80 is preferably 150N / 15mm or less. A preferred range of the seal strength of the second sealing portion 80 is 40N / 15mm to 150N / 15mm, 50N / 15mm to 150N / 15mm, 60N / 15mm to 150N / 15mm, 70N / 15mm to 150N / 15mm, or 85N / 15mm to 150N / 15mm.

[0047] 3, the exterior film 50 has a lid winding portion 50X that is heat-sealed to the lid seal surface 67 of the lid body 60 at the second sealed portion 80. In the exterior film 50, a predetermined area including the first edge 50A excluding the lid winding portion 50X and a predetermined area including the second edge 50B are portions that configure the first sealed portion 70.

[0048] In the all-solid-state battery described in Patent Document 1, depending on the length of the exterior film, wrinkles may be formed in the exterior body when the exterior film and the outer peripheral surface of the lid are heat-sealed. Therefore, one of the objectives of the present embodiment is to provide an electricity storage device 10 in which wrinkles are less likely to be formed in the exterior body 40.

[0049] In this embodiment, the length LA of the lid winding portion 50X and the length LBX of the lid seal surface 67 are set in order to suppress the occurrence of wrinkles in the exterior body 40 when the second sealing portion 80 is formed in the exterior body 40. The length LBX of the lid seal surface 67 is the sum of the length LB3 of the third surface 63, the length LB4 of the fourth surface 64, the length LB5 of the fifth surface 65, and the length LB6 of the sixth surface 66 shown in FIG. 4. In this embodiment, the ratio RA of the length LA to the length LBX is preferably 103% or less. Since the difference between the length LA and the length LBX is small, the exterior film 50 is unlikely to sag. Therefore, the occurrence of wrinkles in the exterior body 40 is suppressed when the second sealing portion 80 is formed in the exterior body 40. The lower limit of the ratio RA is when the length LA is equal to the length LBX, that is, 100%.

[0050] In the electricity storage device 10, the corners of the lid body 60 may be crushed and sealed after the second sealing portion 80 is formed in order to improve the resin filling between the corners of the lid body 60 and the exterior film 50. In this case, the length LA and the length LBX are the lengths of the lid body 60 before the corners are crushed.

[0051] <1-2. Method for manufacturing electricity storage device> 6 is a flowchart showing an example of a method for manufacturing the power storage device 10. The method for manufacturing the power storage device 10 includes, for example, a first step, a second step, a third step, and a fourth step. The first step to the fourth step are performed by, for example, a manufacturing apparatus for the power storage device 10.

[0052] In the first step of step S11, the manufacturing equipment places the lid body 60 with the electrode terminals 30 attached to both ends of the electrode body 20. By completing the first step, the electrode terminals 30 and the electrodes of the electrode body 20 are electrically connected to each other.

[0053] The second process of step S12 is carried out after the first process. In the second process, the manufacturing device wraps the exterior film 50 around the electrode body 20 and the lid body 60.

[0054] The third step of step S13 is performed after the second step. In the third step, the manufacturing apparatus forms the first sealed portion 70 by heat-sealing the heat-fusible resin layer 53 in the portion including the first edge 50A of the exterior film 50 and the heat-fusible resin layer 53 in the portion including the second edge 50B.

[0055] The fourth step of step S14 is carried out after the third step. The manufacturing apparatus forms the second sealed portion 80 by heat-sealing the exterior film 50 and the lid body 60 together.

[0056] <1-3. Actions and Effects of Electricity Storage Devices> In the electricity storage device 10, the seal strength of the second sealing portion 80 is 40 N / 15 mm or more, so that the exterior film 50 and the lid body 60 are firmly joined together. This allows the electrode body 20 to be suitably maintained in a sealed state by the exterior body 40.

[0057] According to the electricity storage device 10, the ratio RA is 103% or less, so that the exterior body 40 is less likely to wrinkle.

[0058] [2. Second embodiment] The power storage device 200 of the second embodiment differs from the first embodiment in that a polymer pool is formed in the second sealing portion 80, but other configurations are similar to those of the first embodiment. The following describes the power storage device 200 of the second embodiment, focusing on the differences from the first embodiment.

[0059] <2-1. Configuration of the power storage device> Fig. 7 is a cross-sectional view of an electricity storage device 200 of the second embodiment, viewed from the side of the second sealing portion 80. Fig. 8 is a cross-sectional view of the second sealing portion 80, viewed from the electrode body 20 side. Fig. 9 is a view of the second sealing portion 80, viewed from the opposite side of the electrode body 20. The electricity storage device 200 includes an inner polysilicon pool 310 and an outer polysilicon pool 320. Note that through-holes 60X are not shown in Figs. 8 and 9.

[0060] As shown in FIG. 8, the inner poly pool 310 is formed between the first surface 61 of the lid body 60 and the exterior film 50, more specifically, at the boundary between the first surface 61 and the exterior film 50. The inner poly pool 310 is a portion where the thermally adhesive resin layer 53 of the exterior film 50 and the resin material constituting the lid body 60 protrude toward the electrode body 20 side. The inner poly pool 310 is formed, for example, at the boundary between the first surface 61 of the lid body 60 and the exterior film 50 along the longitudinal direction of the lid body 60. In the longitudinal direction of the lid body 60, the length of the region where the inner poly pool 310 is formed is a length HA. Note that the inner poly pool 310 may be formed intermittently along the longitudinal direction of the lid body 60 at the boundary between the first surface 61 of the lid body 60 and the exterior film 50. In this case, the length HA is the sum of the lengths of all the inner poly pools 310 in the longitudinal direction of the lid body 60.

[0061] The outer poly pool 320 is formed between the second surface 62 of the lid body 60 and the exterior film 50, more specifically, at the boundary between the second surface 62 and the exterior film 50. The outer poly pool 320 is a portion where the thermally adhesive resin layer 53 of the exterior film 50 and the resin material constituting the lid body 60 protrude to the opposite side to the electrode body 20. The outer poly pool 310 is formed, for example, at the boundary between the second surface 62 of the lid body 60 and the exterior film 50 along the longitudinal direction of the lid body 60. In the longitudinal direction of the lid body 60, the length of the region where the outer poly pool 320 is formed is the length HB. The outer poly pool 320 may be formed intermittently along the longitudinal direction of the lid body 60 at the boundary between the second surface 62 of the lid body 60 and the exterior film 50. In this case, the length HB is the sum of the lengths of all the outer poly pools 320 in the longitudinal direction of the lid body 60.

[0062] The inner poly pool 310 has end points 311 and 312. The outer poly pool 320 has end points 321 and 322. When the inner poly pool 310 and the outer poly pool 320 are formed in the power storage device 200, cracks are likely to occur in the heat-sealable resin layer 53 of the exterior film 50, starting from the end points 311, 312, 321, and 322. For this reason, the peel strength (seal strength) is likely to decrease compared to when no poly pool is formed. When the power storage device 200 is used, gas is generated from the electrode body 20, and the exterior body 40 expands. When the exterior body 40 expands, a force acts from the side closer to the electrode body 20 to peel the exterior film 50 from the lid body 60. For this reason, in this embodiment, by making the length HA shorter than the length HB, the seal strength of the boundary between the first surface 61 of the lid 60 and the exterior film 50 and its surroundings is made higher than the seal strength of the boundary between the second surface 62 of the lid 60 and the exterior film 50 and its surroundings. A specific configuration for making the length HA shorter than the length HB can be achieved, for example, by changing the shape of the lid seal surface 67 of the lid 60.

[0063] 10, for example, the length HA can be made shorter than the length HB by forming a plurality of stripe-like cuts 63X extending along the longitudinal direction of the cover 60 on the third surface 63 of the cover 60. The number of cuts 63X formed on the third surface 63 can be selected arbitrarily. Note that through-holes 60X are not shown in FIGS. 10 to 12.

[0064] 11, for example, the length HA can be made shorter than the length HB by forming a groove 63Y extending along the longitudinal direction of the lid 60 on the third surface 63 of the lid 60. The number of grooves 63Y formed on the third surface 63 can be selected arbitrarily.

[0065] As shown in FIG. 12, by forming an inclined surface 63Z on a portion of the third surface 63 of the lid body 60, which inclines toward the center of the height of the lid body 60 as it moves from the second surface 62 toward the first surface 61, the length HA can be made shorter than the length HB.

[0066] Length HA can be made shorter than length HB, for example, by improving the step of forming second sealing portion 80 (sealing step) in the manufacturing method of electricity accumulation device 200.

[0067] As shown in FIG. 13, for example, in the sealing process, the sealing bar 400 is tilted so that it is closer to the boundary between the first surface 61 and the exterior film 50 than to the boundary between the second surface 62 and the exterior film 50, and then heat-sealing is performed to form the second sealing portion 80, thereby making it possible to make the length HA shorter than the length HB.

[0068] In another example, in the sealing step, the length HA can be made shorter than the length HB by setting the sealing temperature TA of the portion including the boundary between the first surface 61 and the exterior film 50 lower than the sealing temperature TB of the portion including the boundary between the second surface 62 and the exterior film 50. In this example, the sealing temperatures TA and TB may be changed using one sealing bar, or the sealing temperatures TA and TB may be changed using different sealing bars.

[0069] <2-2. Actions and Effects of Electricity Storage Devices> According to the electricity storage device 200, because the length HA is shorter than the length HB, the seal strength of the boundary between the first surface 61 of the lid body 60 and the exterior film 50 and its periphery is higher than the seal strength of the boundary between the second surface 62 of the lid body 60 and the exterior film 50 and its periphery. Therefore, even if the exterior body 40 expands due to use of the electricity storage device 200, peeling of the exterior film 50 from the lid body 60 from the electrode body 20 side is suppressed.

[0070] <3. Modifications> The above-described embodiments are examples of possible forms of the electricity storage device, the lid, and the method for manufacturing the electricity storage device according to the present invention, and are not intended to limit the forms. The electricity storage device, the lid, and the method for manufacturing the electricity storage device according to the present invention may take forms different from those exemplified in the embodiments. One example of such a form is a form in which a part of the configuration of each embodiment is replaced, changed, or omitted, or a form in which a new configuration is added to each embodiment. Below, several examples of modified versions of each embodiment are shown. Note that the following modified versions can be combined with each other as long as there is no technical contradiction.

[0071] <3-1> In the power storage device 10 of the first embodiment and the power storage device 200 of the second embodiment, the position at which the electrode terminal 30 is arranged can be selected arbitrarily. For example, the electrode terminal 30 may protrude from the first sealing portion .

[0072] <3-2> In the electricity storage device 10 of the first embodiment, an inner poly pool 310 and an outer poly pool 320 may be formed as in the second embodiment. In this modification, the length LA of the inner poly pool 310 and the length LB of the outer poly pool 320 may be equal. In this case, even if the exterior body 40 expands, from the viewpoint of suppressing peeling of the exterior film 50 from the lid body 60 from the electrode body 20 side, it is preferable that the ratio RB of the thickness MB of the inner poly pool 310 to the thickness MA of the heat-sealable resin layer 53 is 200% or less. The thickness MB of the inner poly pool 310 is, for example, the length from the first surface 61 of the lid body 60 to the apex of the inner poly pool 310.

[0073] <3-3> In the electric storage device 10 of the first embodiment, the shape of the lid seal surface 67 of the lid body 60 can be changed arbitrarily. For example, as shown in FIG. 14, an inclined surface 63XA and an inclined surface 63XB may be formed on a part of the third surface 63 of the lid body 60. The inclined surface 63XA inclines so as to approach the center of the height direction of the lid body 60 as it moves from the second surface 62 to the first surface 61. The inclined surface 63XB inclines so as to approach the center of the height direction of the lid body 60 as it moves from the first surface 61 to the second surface 62. The inclination angle θAX of the inclined surface 63XA with respect to the fourth surface 64 and the inclination angle θBX of the inclined surface 63XB with respect to the fourth surface 64 are equal. In this modification, when a polymer pool is formed in the electric storage device 10, the length LA of the inner polymer pool 310 and the length LB of the outer polymer pool 320 are substantially equal.

[0074] <3-4> In the electricity storage device 10 of the first embodiment, the configuration of the lid body 60 can be arbitrarily modified. As shown in FIG. 15, the lid body 60 may include a lid main body 60A and a frame 60B that covers the lid main body 60A. In this modification, for example, the material constituting the lid main body 60A is metal. The material constituting the frame 60B is, for example, a resin that can be suitably sealed with the heat-sealable resin layer 53 of the exterior film 50. In this modification, the third surface 63 to the sixth surface 66 of the lid body 60, i.e., the lid seal surface 67, are formed on the frame 60B. In this modification as well, it is preferable that the ratio RA of the length LA to the length LBX is 103% or less.

[0075] <3-5> In the electricity storage device 200 of the second embodiment, the shape of the lid body 60 can be arbitrarily changed. For example, as shown in Fig. 16, the entire third surface 63 may be an inclined surface that approaches the center in the height direction of the lid body 60 from the second surface 62 toward the first surface 61. In this modification, when a polymer pool is formed in the electricity storage device 10, the length LA of the inner polymer pool 310 is shorter than the length LB of the outer polymer pool 320, and therefore, the same effect as the electricity storage device 200 of the second embodiment can be obtained.

[0076] As shown in FIG. 17, an inclined surface 63YA and an inclined surface 63YB may be formed on a part of the third surface 63 of the lid body 60. The inclined surface 63YA is inclined so as to approach the center of the height direction of the lid body 60 as it moves from the second surface 62 to the first surface 61. The inclined surface 63YB is inclined so as to approach the center of the height direction of the lid body 60 as it moves from the first surface 61 to the second surface 62. The inclination angle θAY of the inclined surface 63YA with respect to the fourth surface 64 is larger than the inclination angle θBY of the inclined surface 63YB with respect to the fourth surface 64. In this modification, when a polymer pool is formed in the power storage device 10, the length LA of the inner polymer pool 310 is shorter than the length LB of the outer polymer pool 320, so that the same effect as the power storage device 200 of the second embodiment can be obtained.

[0077] <3-6> The electricity storage device 10 of the first embodiment and the electricity storage device 200 of the second embodiment may have an adhesive film 500 disposed between the exterior film 50 and the lid body 60 in order to suitably bond the exterior film 50 and the lid body 60. In this modification, for example, the lid body 60 with the adhesive film 500 bonded thereto is attached to the openings 40A at both ends of the exterior body 40, and then the second sealing portion 80 is formed.

[0078] FIG. 18 is a cross-sectional view of the electric storage device 200 of the modified example of the second embodiment, seen from the side of the second sealing portion 80. FIG. 19 is a front view of the lid body 60 in a state in which the adhesive film 500 of FIG. 18 is attached. The adhesive film 500 has an adhesive portion 510 that is attached to the exterior film 50 and the lid body 60 in the second sealing portion 80, and a protruding portion 520 that protrudes from the lid seal surface 67 of the lid body 60. Note that the protruding portion 520 is omitted in FIG. 19. The adhesive film 500 is, for example, wrapped around the lid body 60 so as to cover the entire surface of the lid seal surface 67 of the lid body 60. In this modified example, the inner poly pool 310 is formed between the exterior film 50 and the first surface 61 of the lid body 60, more specifically, at the boundary between the exterior film 50 and the adhesive film 500. The outer poly pool 320 is formed between the exterior film 50 and the second surface 62 of the lid 60, more specifically, at the boundary between the exterior film 50 and the adhesive film 500. The adhesive film 500 has a protruding portion 520, so that the adhesive film 500 is configured to be wider than the lid seal surface 67 of the lid 60 as a whole. This allows the adhesive film 500 to be easily adhered to the lid 60. Furthermore, the adhesive film 500 covers the corners of the boundary between the surfaces of the lid 60, so that the adhesion between the lid 60 and the adhesive film 500 is enhanced. The inner poly pool 310 and the outer poly pool 320 may also be formed between the lid 60 and the adhesive film 500.

[0079] The adhesive film 500 can be selected arbitrarily as long as it is a film capable of adhering the exterior film 50 and the lid body 60. The adhesive film 500 is preferably a laminate (laminate film) having at least a heat-sealable resin layer, a heat-resistant base material layer, and a heat-sealable resin layer in this order. The specifications of the heat-sealable resin layer of the adhesive film 500 can be the same as those of the heat-sealable resin layer 53. The materials constituting the heat-sealable resin layers on both sides of the adhesive film 500 may be the same or different materials, and are appropriately selected according to the materials constituting the heat-sealable resin layer 53 of the exterior film 50 and the materials constituting the lid body 60. The material constituting the heat-sealable resin layer on the side of the adhesive film 500 that is adhered to the lid body 60 is preferably an acid-modified polyolefin resin graft-modified with an acid such as maleic anhydride. The heat-sealable resin layer of the adhesive film 500 on the side to be bonded to the exterior film 50 is preferably made of the same type of material as that constituting the heat-sealable resin layer 53 of the exterior film 50 .

[0080] The heat-resistant base layer may be any film made of a heat-resistant resin, such as a non-stretched or stretched film of polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polymethylpentene (registered trademark), polyacetal cyclic polyolefin, polyethylene, polypropylene, etc. Polyethylene terephthalate is particularly preferred because it is inexpensive and has high strength.

[0081] The adhesive film 500 preferably has adhesiveness. When the second sealing portion 80 is formed with the adhesive film 500 disposed between the exterior film 50 and the lid 60, the adhesive film 500 is unlikely to be displaced relative to the lid 60 and the exterior film 50. By incorporating a tackifier resin into the heat-sealable resin layer of the adhesive film 500, the adhesive film 500 can be given adhesiveness. Examples of the tackifier resin include amorphous polyolefins. Examples of the amorphous polyolefins include amorphous polypropylene and copolymers of amorphous propylene and other α-olefins. The content of the tackifier resin in the base material constituting the heat-sealable resin is preferably 10 to 20% by weight or less.

[0082] In this modification, in order to suppress the occurrence of wrinkles in the exterior body 40 when the second sealing portion 80 is formed in the exterior body 40, the length LA (see FIG. 3) of the lid winding portion 50X and the length LCX of the adhesive portion 510 may be set. The length LCX of the adhesive portion 510 is the sum of the lengths LC3, LC4, LC5, and LC6. The length LC3 is the length of the portion of the adhesive portion 510 that is adhered to the third surface 63. The length LC4 is the length of the portion of the adhesive portion 510 that is adhered to the fourth surface 64. The length LC5 is the length of the portion of the adhesive portion 510 that is adhered to the fifth surface 65. The length LC6 is the length of the portion of the adhesive portion 510 that is adhered to the sixth surface 66. In this modification, the ratio RC of the length LA to the length LCX is preferably 103% or less. Since the difference between the length LA and the length LCX is small, the exterior film 50 is less likely to sag. This prevents wrinkles from occurring in package 40 when second sealing portion 80 is formed in package 40. The lower limit of ratio RC is when length LA and length LCX are equal, that is, 100%.

[0083] [4. Working Example] The inventors of the present application conducted a first test and a second test on the electricity storage devices of the examples and the comparative example. The first test is a test to measure the seal strength of the second sealing portion 80. The second test is a test to check the presence or absence of wrinkles in the exterior body 40. For ease of explanation, the following will be described with the same reference numerals as in the embodiment for the elements constituting the electricity storage devices of the examples and the comparative example that are the same as in the embodiment.

[0084] <4-1. First test> In the first test, the electricity storage devices of Examples 1 to 7 and the electricity storage devices of Comparative Examples 1 and 2 were manufactured, and cross-sections were observed to observe the state of the plastic puddle, and the seal strength was measured by peeling off the exterior film 50 from the first surface 61 side of the lid body 60 toward the second surface 62 side using an autograph (AG-Xplus manufactured by Shimadzu Corporation). The seal strength was measured in the following manner. The lid body 60 and the exterior film 50 to be measured were cut out from the manufactured electricity storage devices 10 of the Examples and Comparative Examples, and the exterior film 50 side was cut into a width of 15 mm in the measurement direction, and the lid body 60 was chucked on the lower side of the autograph chuck part and the exterior film 50 on the upper side, and the measurement was performed at 300 mm / min. The specifications of the electricity storage devices of Examples 1 to 5 and the electricity storage devices of Comparative Examples 1 and 2 are as follows.

[0085] The electricity storage devices of Examples 1, 5, and 6 are the electricity storage device 10 according to the first embodiment. The electricity storage devices of Examples 2 to 4, and 7 are the electricity storage device 200 according to the second embodiment. The lid body 60 of the electricity storage device 200 of Examples 2 and 7 has a shape shown in FIG. 12, and an inclined surface 63Z is formed on the third surface 63. The lid body 60 of the electricity storage device 200 of Example 3 has a shape shown in FIG. 10, and a notch 63X is formed on the third surface 63. The lid body 60 of the electricity storage device 200 of Example 4 has a shape shown in FIG. 11, and a groove 63Y is formed on the third surface 63.

[0086] The sealing conditions for the second sealed portion 80 of the electricity storage devices of Examples 1 to 4 are a temperature of 220°C, a time of 5 seconds, and a pressure of 0.4 MPa. The sealing conditions for the second sealed portion 80 of the electricity storage device of Example 5 are a temperature of 230°C, a time of 5 seconds, and a pressure of 0.4 MPa. The sealing conditions for the second sealed portion 80 of the electricity storage device of Example 6 are a temperature of 200°C, a time of 5 seconds, and a pressure of 0.4 MPa. The sealing conditions for the second sealed portion 80 of the electricity storage device of Example 7 are a temperature of 210°C, a time of 5 seconds, and a pressure of 0.4 MPa.

[0087] The energy storage devices of Examples 1, 5, and 6 have an inner poly reservoir 310 and an outer poly reservoir 320, and lengths LA and LB are equal. The energy storage device of Example 1 has a ratio RB of 160%. The energy storage device of the fifth embodiment has a ratio RB of 240%. The energy storage device of Example 6 has a ratio RB of 260%. The energy storage devices of Examples 2 to 4 and 7 have an inner poly reservoir 310 and an outer poly reservoir 320, and lengths LA are shorter than length LB.

[0088] The specifications of the electricity storage device of Comparative Example 1 are the same as those of the electricity storage device of Example 1, except for the sealing conditions of the second sealed portion 80. The sealing conditions of the second sealed portion 80 of the electricity storage device of Comparative Example 1 are a temperature of 190° C., a time of 5 seconds, and a pressure of 0.4 MPa. The electricity storage device of Comparative Example 1 does not have an inner poly pool 310 or an outer poly pool 320.

[0089] The specifications of the electricity storage device of Comparative Example 2 are the same as those of the electricity storage devices of Examples 2 to 4, except for the sealing conditions of second sealing portion 80. The sealing conditions of second sealing portion 80 of the electricity storage device of Comparative Example 2 are a temperature of 220°C, a time of 3 seconds, and a pressure of 0.4 MPa. The electricity storage device of Comparative Example 2 has inner poly pool 310 and outer poly pool 320, and length LA is longer than length LB.

[0090] FIG. 20 is a table showing the test results of the first test. It was confirmed that in the electricity storage devices of Examples 1 to 7, a high seal strength was obtained as the seal strength of the second sealing portion 80. From the test results of the electricity storage device of Example 1, it was confirmed that even if the length LA and the length LB are equal, the seal strength is high by setting the ratio RB to 200% or less. From the test results of the electricity storage devices of Examples 2 to 4, it was confirmed that the seal strength is high by setting the length LA shorter than the length LB. It was confirmed that the seal strength of the second sealing portion 80 of the electricity storage devices of Examples 5 and 6 is lower than that of the electricity storage device of Example 1. One of the reasons for this is thought to be that the ratio RB is 200% or more.

[0091] <4-2. Second test> In a second test, the electricity storage devices of Examples 8 and 9 and the electricity storage device of Comparative Example 3 were manufactured, and the number of wrinkles in the exterior body 40 was visually confirmed. The specifications of the electricity storage devices of Examples 8 and 9 and the electricity storage device of Comparative Example 3 were as follows.

[0092] The electricity storage devices of Examples 8 and 9 are the electricity storage device 10 related to the first embodiment. In the electricity storage devices of Examples 8 and 9, the sealing conditions for the first sealing portion 70 are a temperature of 210°C, a time of 5 seconds, and a pressure of 0.5 MPa, and the sealing conditions for the second sealing portion 80 are a temperature of 220°C, a time of 5 seconds, and a pressure of 0.5 MPa. The electricity storage device of Example 8 has a ratio RA of 100%. The electricity storage device of Example 9 has a ratio RA of 103%.

[0093] The specifications of the electricity storage device of Comparative Example 3, except for the ratio RA, are the same as those of the electricity storage devices of Examples 8 and 9. The ratio RA of the electricity storage device of Comparative Example 3 is 105%.

[0094] Figure 21 is a table showing the test results of the second test. In the "Occurrence of wrinkles" column in Figure 18, "◯" indicates that no wrinkles were present, "△" indicates that wrinkles were present in three or fewer places, and "×" indicates that wrinkles were present in four or more places.

[0095] It was confirmed that no wrinkles were formed or the formation of wrinkles was suppressed in the exterior body 40 in Examples 8 and 9. This is believed to be because the electricity storage devices in Examples 8 and 9 had a ratio RA of 103% or less. [Explanation of symbols]

[0096] 10, 200: Power storage device 20: Electrode body 40: Exterior body 50: Exterior film 53: Heat-fusible resin layer 60: Lid 61: 1st page 62: 2nd side 63X:Notch 63XA: Inclined surface 63XB: Inclined surface 63YA: Inclined surface 63YB: Inclined surface 63Y: Groove 63Z: Inclined surface 67: Lid sealing surface 70: First sealing part 80: Second sealing part 310: Inner poly pool 320: Outside Poly Pool 500: Adhesive film 510: Adhesive part

Claims

1. A lid body, which is one of the components constituting an outer casing for an electricity storage device that seals an electrode body, the outer casing for the electricity storage device includes an outer casing film that is wrapped around the electrode body so as to have an opening that is rectangular in plan view, In each component constituting the outer casing for the power storage device, the side facing the electrode body is defined as the inside, the side opposite to the side facing the electrode body is defined as the outside, the direction along the long side of the opening is defined as the longitudinal direction, and the direction along the short side of the opening is defined as the lateral direction, the lid is disposed at the opening, has a rectangular shape in a plan view, and includes a lid sealing surface that is sealed with the exterior film, the lid sealing surface includes a first sealing surface constituting one surface in the longitudinal direction, a second sealing surface constituting the other surface in the longitudinal direction, a third sealing surface constituting one surface in the lateral direction, and a fourth sealing surface constituting the other surface in the lateral direction; An inclined surface is provided in an inner end region of the first seal surface, the inclined surface inclining toward the center of the lid body in the short side direction as it moves from the outer side toward the inner side. Lid body.

2. A lid body, which is one of the components constituting an outer casing for an electricity storage device that seals an electrode body, the outer casing for the electricity storage device includes an outer casing film that is wrapped around the electrode body so as to have an opening that is rectangular in plan view, In each component constituting the outer casing for the power storage device, the side facing the electrode body is defined as the inside, the side opposite to the side facing the electrode body is defined as the outside, the direction along the long side of the opening is defined as the longitudinal direction, and the direction along the short side of the opening is defined as the lateral direction, the lid is disposed at the opening, has a rectangular shape in a plan view, and includes a lid sealing surface that is sealed with the exterior film, the lid sealing surface includes a first sealing surface constituting one surface in the longitudinal direction, a second sealing surface constituting the other surface in the longitudinal direction, a third sealing surface constituting one surface in the lateral direction, and a fourth sealing surface constituting the other surface in the lateral direction; The entire first sealing surface is an inclined surface that inclines toward the center of the lid body in the short side direction as it moves from the outside toward the inside. Lid body.

3. A lid body, which is one of the components constituting an outer casing for an electricity storage device that seals an electrode body, the outer casing for the electricity storage device includes an outer casing film that is wrapped around the electrode body so as to have an opening that is rectangular in plan view, In each component constituting the outer casing for the power storage device, the side facing the electrode body is defined as the inside, the side opposite to the side facing the electrode body is defined as the outside, the direction along the long side of the opening is defined as the longitudinal direction, and the direction along the short side of the opening is defined as the lateral direction, the lid is disposed at the opening, has a rectangular shape in a plan view, and includes a lid sealing surface that is sealed with the exterior film, the lid sealing surface includes a first sealing surface constituting one surface in the longitudinal direction, a second sealing surface constituting the other surface in the longitudinal direction, a third sealing surface constituting one surface in the lateral direction, and a fourth sealing surface constituting the other surface in the lateral direction; a first inclined surface inclined from the outer side toward the inner side in an inner end region of the first sealing surface so as to approach a center in the short side direction of the lid body as it moves from the outer side toward the inner side; a second inclined surface inclined from the inside toward the outside so as to approach the center of the lid in the short side direction, in the outer end region of the first sealing surface; Lid body.

4. A lid body, which is one of the components constituting an outer casing for an electricity storage device that seals an electrode body, the outer casing for the electricity storage device includes an outer casing film that is wrapped around the electrode body so as to have an opening that is rectangular in plan view, In each component constituting the outer casing for the power storage device, the side facing the electrode body is defined as the inside, the side opposite to the side facing the electrode body is defined as the outside, the direction along the long side of the opening is defined as the longitudinal direction, and the direction along the short side of the opening is defined as the lateral direction, the lid is disposed at the opening, has a rectangular shape in a plan view, and includes a lid sealing surface that is sealed with the exterior film, the lid sealing surface includes a first sealing surface constituting one surface in the longitudinal direction, a second sealing surface constituting the other surface in the longitudinal direction, a third sealing surface constituting one surface in the lateral direction, and a fourth sealing surface constituting the other surface in the lateral direction; a first inclined surface inclined from the outer side toward the inner side in an inner end region of the first sealing surface so as to approach a center in the short side direction of the lid body as it moves from the outer side toward the inner side; a second inclined surface inclined from the inside toward the outside so as to approach a center in the short side direction of the lid body, The inclination angle of the first inclined surface is larger than the inclination angle of the second inclined surface. Lid body.

5. A lid body, which is one of the components constituting an outer casing for an electricity storage device that seals an electrode body, the outer casing for the electricity storage device includes an outer casing film that is wrapped around the electrode body so as to have an opening that is rectangular in plan view, In each component constituting the outer casing for the power storage device, the side facing the electrode body is defined as the inside, the side opposite to the side facing the electrode body is defined as the outside, the direction along the long side of the opening is defined as the longitudinal direction, and the direction along the short side of the opening is defined as the lateral direction, the lid is disposed at the opening, has a rectangular shape in a plan view, and includes a lid sealing surface that is sealed with the exterior film, the lid sealing surface includes a first sealing surface constituting one surface in the longitudinal direction, a second sealing surface constituting the other surface in the longitudinal direction, a third sealing surface constituting one surface in the lateral direction, and a fourth sealing surface constituting the other surface in the lateral direction; The first sealing surface has a stripe-like cut along the longitudinal direction. Lid body.

6. A lid body, which is one of the components constituting an outer casing for an electricity storage device that seals an electrode body, the outer casing for the electricity storage device includes an outer casing film that is wrapped around the electrode body so as to have an opening that is rectangular in plan view, In each component constituting the outer casing for the power storage device, the side facing the electrode body is defined as the inside, the side opposite to the side facing the electrode body is defined as the outside, the direction along the long side of the opening is defined as the longitudinal direction, and the direction along the short side of the opening is defined as the lateral direction, the lid is disposed at the opening, has a rectangular shape in a plan view, and includes a lid sealing surface that is sealed with the exterior film, the lid sealing surface includes a first sealing surface constituting one surface in the longitudinal direction, a second sealing surface constituting the other surface in the longitudinal direction, a third sealing surface constituting one surface in the lateral direction, and a fourth sealing surface constituting the other surface in the lateral direction; The first sealing surface has a groove along the longitudinal direction. Lid body.

7. An electrode body; an outer casing for an electricity storage device that seals the electrode assembly, An electricity storage device in which the electrode body is sealed with the electricity storage device outer casing, The outer casing for the electricity storage device includes an outer casing film that is wrapped around the electrode body so as to have an opening that is rectangular in plan view; a lid body that is disposed at the opening and has a rectangular shape in a plan view; a first sealing portion formed by sealing opposing surfaces of the exterior film; a second sealing portion formed by sealing the facing surfaces of the lid body and the exterior film together, In each component constituting the outer casing for the power storage device, the side facing the electrode body is defined as the inside, the side opposite to the side facing the electrode body is defined as the outside, the direction along the long side of the opening is defined as the longitudinal direction, and the direction along the short side of the opening is defined as the lateral direction, the lid body has a lid sealing surface that faces the exterior film and is sealed in the second sealing portion, the lid sealing surface includes a first sealing surface constituting one surface in the longitudinal direction, a second sealing surface constituting the other surface in the longitudinal direction, a third sealing surface constituting one surface in the lateral direction, and a fourth sealing surface constituting the other surface in the lateral direction; an inner poly pool is formed along the longitudinal direction between the inner end of the first sealing surface and the exterior film; an outer poly pool is formed along the longitudinal direction between the outer edge of the first sealing surface and the exterior film; The seal strength between the first seal surface and the exterior film is 40 N / 15 mm or more. Energy storage device.

8. An electrode body; an outer casing for an electricity storage device that seals the electrode assembly, An electricity storage device in which the electrode body is sealed with the electricity storage device outer casing, The outer casing for the electricity storage device includes an outer casing film that is wrapped around the electrode body so as to have an opening that is rectangular in plan view; a lid body that is disposed at the opening and has a rectangular shape in a plan view; a first sealing portion formed by sealing opposing surfaces of the exterior film; a second sealing portion formed by sealing the facing surfaces of the lid body and the exterior film together, In each component constituting the outer casing for the power storage device, the side facing the electrode body is defined as the inside, the side opposite to the side facing the electrode body is defined as the outside, the direction along the long side of the opening is defined as the longitudinal direction, and the direction along the short side of the opening is defined as the lateral direction, the lid body has a lid sealing surface that faces the exterior film and is sealed in the second sealing portion, the lid sealing surface includes a first sealing surface constituting one surface in the longitudinal direction, a second sealing surface constituting the other surface in the longitudinal direction, a third sealing surface constituting one surface in the lateral direction, and a fourth sealing surface constituting the other surface in the lateral direction; an inner poly pool is formed along the longitudinal direction between the inner end of the first sealing surface and the exterior film; an outer poly pool is formed along the longitudinal direction between the outer edge of the first sealing surface and the exterior film; The length of the inner poly reservoir is shorter than the length of the outer poly reservoir. Energy storage device.

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