Electricity storage device, reinforcement member, and method for manufacturing electricity storage device

Abstract

This electricity storage device is provided with: an electrode body; an electrode terminal electrically connected to the electrode body; a reinforcing member disposed on a side of the electrode body; and an exterior film for packaging the electrode body and the reinforcing member. The reinforcing member includes: a main body portion; and a movable part connected to the main body part and joined to the exterior film, the movable part being configured so as to be movable with respect to the main body part when the exterior film expands in accordance with an increase in the internal pressure of the electricity storage device.

Description

[0001] (This application is a divisional application of application No. 202380057354.7 filed on August 10, 2023.) Technical Field

[0002] The present invention relates to an electricity storage device, a reinforcing member for an electricity storage device, and a method for manufacturing the electricity storage device. Background Art

[0003] Patent Document 1 discloses an all-solid-state battery as an example of an electrical storage device. The all-solid-state battery includes an electrode body, an electrode terminal, and an outer casing that seals the electrode body. The outer casing includes an outer film wrapped around the electrode body with an opening, and a cover disposed in the opening. One end of the electrode terminal is electrically connected to the electrode body. The other end of the electrode terminal is exposed outside the cover. The electrode terminal extends through the cover.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-153504 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] In the above-mentioned electricity storage device, a gap may be formed between the electrode terminal penetrating the cover and the cover, thereby reducing the sealing performance of the electricity storage device.

[0009] The present invention provides an electricity storage device with high sealing performance, a reinforcing member for the electricity storage device, and a method for manufacturing the electricity storage device.

[0010] Methods for solving problems

[0011] The first aspect of the present invention provides an electrical storage device comprising: an electrode body; an electrode terminal electrically connected to the electrode body; a reinforcing member arranged on the side of the electrode body; and an outer film for packaging the electrode body and the reinforcing member, wherein the electrode terminal has an exposed portion, the exposed portion being a portion exposed to the outside on the side opposite to the electrode body relative to the reinforcing member, and a portion of the exposed portion being bonded to the outer film.

[0012] According to a second aspect of the present invention, in the electricity storage device according to the first aspect, the reinforcing member includes at least a first member and a second member that are divided.

[0013] In the electricity storage device according to a third aspect of the present invention, in the electricity storage device according to the first aspect or the second aspect, the electrode body includes a current collector, and the reinforcing member has a recess for accommodating the current collector.

[0014] In the electricity storage device according to a fourth aspect of the present invention, in the electricity storage device according to the first aspect or the second aspect, the electrode assembly includes a current collector, and the reinforcing member is a frame having a space for arranging the current collector.

[0015] According to a fifth aspect of the present invention, in the electricity storage device according to any one of the first to third aspects, the reinforcing member is plate-shaped and has a hole into which the electrode terminal is inserted.

[0016] In the energy storage device according to the sixth aspect of the present invention, in the energy storage device according to the first aspect or the second aspect, the reinforcing member includes: a main body; and a movable part connected to the main body and joined to the outer film, the movable part being configured to be movable relative to the main body when the outer film expands as the internal pressure of the energy storage device increases.

[0017] In the storage device of the 7th aspect of the present invention, in the storage device of the 1st aspect or the 2nd aspect, the reinforcing component includes: a first surface facing the electrode body; and a second surface, which is connected to the first surface and extends in a direction opposite to the electrode body, and the second surface is inclined toward the center of the height direction of the reinforcing component as it goes in the direction opposite to the electrode body.

[0018] According to an eighth aspect of the present invention, in the energy storage device according to the first or second aspect, the reinforcing member includes a main body portion and an extension portion extending from the main body portion toward the electrode body, wherein the extension portion tapers toward the electrode body.

[0019] The storage device according to the ninth aspect of the present invention is the storage device according to any one of the first to eighth aspects, comprising a buffer film arranged on the inner side of the outer film to improve the strength of the outer film, the buffer film being arranged at at least one of the corners of the electrode body and the corners of the reinforcing member.

[0020] The storage device according to the tenth aspect of the present invention is the storage device according to any one of the first to ninth aspects, wherein the electrode body and the reinforcing member are arranged at a distance from each other, the outer film has an expansion portion located between the electrode body and the reinforcing member, and the expansion portion is configured to bulge when the outer film expands as the internal pressure of the storage device increases.

[0021] The storage device of the 11th aspect of the present invention includes: an electrode body; an electrode terminal electrically connected to the electrode body; a reinforcing component arranged on the side of the electrode body; and an outer film for packaging the electrode body and the reinforcing component, the reinforcing component including: a main body; and a movable part connected to the main body and joined to the outer film, the movable part being configured to be movable relative to the main body when the outer film expands as the internal pressure of the storage device increases.

[0022] The storage device of the 12th aspect of the present invention includes: an electrode body; an electrode terminal electrically connected to the electrode body; a reinforcing component arranged on the side of the electrode body; and an outer film for packaging the electrode body and the reinforcing component, the reinforcing component including: a first surface facing the electrode body; and a second surface connected to the first surface and extending in a direction opposite to the electrode body, the second surface being inclined toward the center of the height direction of the reinforcing component as it extends in a direction opposite to the electrode body.

[0023] The storage device of the 13th aspect of the present invention includes: an electrode body; an electrode terminal electrically connected to the electrode body; a reinforcing component arranged on the side of the electrode body; and an outer film for packaging the electrode body and the reinforcing component, the reinforcing component including: a main body; and an extension portion extending from the main body toward the electrode body, the extension portion becoming thinner at the front end as it goes toward the electrode body.

[0024] The storage device of the 14th aspect of the present invention includes: an electrode body; an electrode terminal electrically connected to the electrode body; a reinforcing component arranged on the side of the electrode body; and an outer film that wraps the electrode body and the reinforcing component, a buffer film that is arranged on the inner side of the outer film and is used to increase the strength of the outer film, and the buffer film is arranged at at least one of the corners of the electrode body and the corners of the reinforcing component.

[0025] The storage device of the 15th aspect of the present invention includes: an electrode body; an electrode terminal electrically connected to the electrode body; a reinforcing member arranged on the side of the electrode body; and an outer film for packaging the electrode body and the reinforcing member, the electrode body and the reinforcing member being arranged at a distance from each other, the outer film having an expansion portion located between the electrode body and the reinforcing member, and the expansion portion being configured to bulge when the outer film expands as the internal pressure of the storage device increases.

[0026] According to a sixteenth aspect of the present invention, in the electricity storage device according to any one of the eleventh to fifteenth aspects, the reinforcing member includes at least a first member and a second member that are divided.

[0027] According to a seventeenth aspect of the present invention, in the electricity storage device according to any one of the eleventh to fifteenth aspects, the electrode body includes a current collector, and the reinforcing member has a recess for accommodating the current collector.

[0028] According to an eighteenth aspect of the present invention, in the electricity storage device according to any one of the eleventh to fifteenth aspects, the reinforcing member is plate-shaped and has a hole into which the electrode terminal is inserted.

[0029] A reinforcing member according to a nineteenth aspect of the present invention is used in the electricity storage device according to any one of the first to eighteenth aspects.

[0030] A reinforcing member according to a 20th aspect of the present invention is the reinforcing member according to the 19th aspect, wherein the reinforcing member is joined to the electrode terminal.

[0031] The manufacturing method of the storage device according to the twenty-first aspect of the present invention is a method for manufacturing a storage device, comprising an electrode body, an electrode terminal electrically connected to the electrode body, a reinforcing member arranged on the side of the electrode body, and an outer film for packaging the electrode body and the reinforcing member. The electrode terminal has an exposed portion, which is a portion exposed to the outside on the side opposite to the electrode body relative to the reinforcing member, and a portion of the exposed portion is bonded to the outer film. The manufacturing method of the storage device includes: a connection step for electrically connecting the electrode body to the electrode terminal; a configuration step for configuring the reinforcing member to form the exposed portion, which is performed after the connection step; a packaging step for packaging the reinforcing member and the electrode body with the outer film, which is performed after the configuration step; and a sealing step for bonding the outer film to the exposed portion, which is performed after the packaging step.

[0032] According to a 22nd aspect of the present invention, in the method for manufacturing an electricity storage device according to the 21st aspect, in the arranging step, the reinforcing member is arranged by insert molding on the electrode terminal connected to the electrode assembly.

[0033] Effects of the Invention

[0034] According to the present invention, it is possible to provide an electricity storage device having high sealing performance, a reinforcing member for the electricity storage device, and a method for manufacturing the electricity storage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a perspective view of the electricity storage device according to the embodiment.

[0036] Figure 2 yes Figure 1 A top view of a power storage device.

[0037] Figure 3 Yes Figure 1 A cross-sectional view of the layer structure of an exterior film included in an electricity storage device.

[0038] Figure 4 yes Figure 1 A perspective view of a reinforcement member included in an electric storage device.

[0039] Figure 5 It is along Figure 2 Cross-sectional view of line D5-D5.

[0040] Figure 6 Yes Figure 1 A flowchart of an example of a method for manufacturing an electricity storage device.

[0041] Figure 7 It is a cross-sectional view of the electricity storage device according to the first modification.

[0042] Figure 8 It is a cross-sectional view of an electricity storage device according to a second modification.

[0043] Figure 9 It is a perspective view of a reinforcing member included in the electricity storage device according to the third modification.

[0044] Figure 10 It is a cross-sectional view of an electricity storage device according to a third modification.

[0045] Figure 11 yes Figure 10 A cross-sectional view of a state where the internal pressure of the outer casing of the electricity storage device increases.

[0046] Figure 12 It is a perspective view of a reinforcing member included in the electricity storage device according to the fourth modification.

[0047] Figure 13 It is a cross-sectional view of an electricity storage device according to a fourth modification.

[0048] Figure 14 It is a perspective view of a reinforcing member included in the electricity storage device according to the fifth modification.

[0049] Figure 15 It is a cross-sectional view of an electricity storage device according to a fifth modification.

[0050] Figure 16 It is a cross-sectional view of an electricity storage device according to a sixth modification.

[0051] Figure 17 It is a cross-sectional view of an electricity storage device according to a seventh modification.

[0052] Figure 18 It is a cross-sectional view of an electricity storage device according to an eighth modification.

[0053] Figure 19It is a plan view of an electricity storage device according to another modified example of the embodiment.

[0054] Figure 20 yes Figure 19 Side view of a power storage device.

[0055] Figure 21 It is a plan view of a power storage device according to still another modified example of the embodiment. DETAILED DESCRIPTION

[0056] Hereinafter, an electric storage device according to an embodiment of the present invention will be described with reference to the accompanying drawings. In addition, the same reference numerals are given to the same or corresponding parts in the figures, and their description will not be repeated. In addition, in the present embodiment, the numerical range represented by "~" means "above" or "below". For example, the expression 2 to 15 mm means above 2 mm and below 15 mm. In the numerical ranges recorded in stages in the present embodiment, the upper limit value or lower limit value recorded in a certain numerical range may also be replaced by the upper limit value or lower limit value of the numerical range recorded in other stages. In addition, the upper limit value and the upper limit value, the upper limit value and the lower limit value, or the lower limit value and the lower limit value recorded separately may be combined as numerical ranges.

[0057] [1. Implementation Method]

[0058] <1-1. Structure of the Energy Storage Device>

[0059] Figure 1 It is a perspective view schematically showing the electricity storage device 10 according to the embodiment. Figure 2 yes Figure 1 10 is a top view of the power storage device 10. Figure 3 Yes Figure 1 1 is a cross-sectional view showing the layer structure of the exterior film 50 included in the power storage device 10 . Figure 4 yes Figure 1 1 is a perspective view of a reinforcing member 60 included in the electricity storage device 10 . Figure 5 It is along Figure 2 The cross-sectional view of the D5-D5 line. Figure 2 and Figure 5 , arrows UD and LR indicate the thickness direction of the energy storage device 10, and arrows LR and FB indicate the width direction of the energy storage device 10. Arrows FB and UD indicate the depth direction of the energy storage device 10. The directions indicated by arrows UD, LR, and FB are the same in the following figures.

[0060] The energy storage device 10 includes an electrode body 20, an electrode terminal 30, and an outer body 40. The electrode body 20 includes, for example, electrodes (positive and negative electrodes) and a separator that constitute an energy storage component such as a lithium-ion battery, a capacitor, or an all-solid-state battery. In the present embodiment, the shape of the electrode body 20 is roughly rectangular. In addition, "roughly rectangular" includes, in addition to a complete rectangular parallelepiped, a solid that is considered to be a rectangular parallelepiped by, for example, modifying the shape of a portion of the outer surface. The shape of the electrode body 20 can be, for example, a cylinder or a polygonal prism.

[0061] In this embodiment, the energy storage device 10 includes two electrode terminals 30. The electrode terminals 30 are metal terminals used for inputting and outputting power to and from 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 by being connected to the current collector 20X. The other end of the electrode terminal 30 protrudes outward from, for example, an edge of the outer casing 40.

[0062] The metal material constituting the electrode terminal 30 is, for example, aluminum, nickel, or copper. For example, in the case of a lithium-ion battery, the electrode terminal 30 connected to the positive electrode is typically made of aluminum, while the electrode terminal 30 connected to the negative electrode is typically made of copper, nickel, or the like. Furthermore, the outermost layer of the electrode body 20 does not necessarily have to be an electrode; for example, it may also be a protective tape or a separator.

[0063] The outer casing 40 seals the electrode body 20. The outer casing 40 includes an outer film 50 and a reinforcing member 60. The outer film 50 encapsulates the electrode body 20 and the reinforcing member 60 disposed on the side of the electrode body 20. In this embodiment, a single outer film 50 is wound around the electrode body 20 and the reinforcing member 60. The outer film 50 is preferably wound around the electrode body 20 and the reinforcing member 60 in the MD (Machine Direction).

[0064] The electrode terminal 30 is joined to the reinforcing member 60 in a manner having an exposed portion 30A, which is a portion exposed to the outside of the electrode body 20 on the opposite side of the reinforcing member 60. From the perspective of properly joining the electrode terminal 30 to the reinforcing member 60, it is preferable to join the adhesive film 31 to the electrode terminal 30. The adhesive film 31 can be arbitrarily selected as long as it is a film that can adhere the electrode terminal 30 made of metal to the reinforcing member 60 made of resin. The adhesive film 31 can be made of, for example, a polyolefin resin such as a polyethylene resin or a polypropylene resin, a cyclic polyolefin resin, or an acid-modified polyolefin resin obtained by grafting these polyolefin resins with an acid such as maleic anhydride. The adhesive film 31 can be a single layer or a film of two or more layers. A gas absorbent, a water absorbent, etc. can be added to the material constituting the adhesive film 31 as needed. When a gas absorbent is added to the material constituting the adhesive film 31, it can absorb gas present within the energy storage device 10 that is about to leak out of the device, as well as gas that is about to enter the device from outside. When a water absorbent is added to the material constituting the adhesive film 31, it can absorb moisture present within the energy storage device 10 that is about to leak out of the device, as well as moisture that is about to enter the device from outside. Known water absorbents can be used as the water absorbent, and inorganic water absorbents are preferred. Preferred examples of inorganic water absorbents include calcium oxide, anhydrous magnesium sulfate, magnesium oxide, calcium chloride, zeolite, aluminum oxide, silica gel, aluminum oxide gel, and burnt alum. Known gas absorbents can be used as the gas absorbent. For example, hydrophobic zeolite with a SiO2 / Al2O3 molar ratio of 1 / 1 to 2000 / 1, bentonite, sepiolite, calcium oxide, copper oxide, or zinc oxide can be used. In the present embodiment, the adhesive film 31 is bonded to substantially the entire portion of the electrode terminal 30 covered by the reinforcing member 60 and to a portion bonded to the exterior film 50 for forming a terminal sealing portion 90 described later.

[0065] For example, there is a method of forming a housing portion (depression) for accommodating the electrode body 20 in the outer film 50 by cold forming. However, it is not necessarily easy to form a deep housing portion by such a method. If you want to form a housing portion (depression) deeper by cold forming (for example, a forming depth of 15 mm), the possibility of pinholes or cracks being generated in the outer film 50 and causing a decrease in battery performance becomes higher. On the other hand, in the present embodiment, the outer body 40 seals the electrode body 20 by winding the outer film 50 around the electrode body 20, so the electrode body 20 can be easily sealed regardless of the thickness of the electrode body 20. Among them, in order to reduce the dead zone between the electrode body 20 and the outer film 50 to increase the volume energy density of the storage device 10, it is preferred that the outer film 50 is wound in a manner in contact with the outer surface of the electrode body 20. In addition, when the energy storage device 10 is an all-solid-state battery, from the perspective of applying high pressure uniformly from the outer surface of the battery in order to exert battery performance, it is also necessary to eliminate the space between the electrode body 20 and the outer film 50. Therefore, it is preferred that the outer film 50 is wound in a manner that is in contact with the outer surface of the electrode body 20.

[0066] like Figure 3 As shown, the exterior film 50 is, for example, a laminate (laminated film) comprising, in order, a base layer 51, a barrier layer 52, and a heat-weldable resin layer 53. However, the exterior film 50 need not include all of these layers; for example, the barrier layer 52 may not be included. Specifically, the exterior film 50 can be made of any flexible and easily bendable material, such as a resin film. Furthermore, the exterior film 50 is preferably heat-sealable.

[0067] The base layer 51 included in the exterior film 50 is a layer used to impart heat resistance to the exterior film 50 and to suppress the formation of pinholes that may occur during processing or distribution. The base layer 51 may be composed, for example, of at least one of a stretched polyester resin layer and a stretched polyamide resin layer. For example, by including at least one of the stretched polyester resin layer and the stretched polyamide resin layer in the base layer 51, the barrier layer 52 can be protected during processing of the exterior film 50, thereby suppressing breakage of the exterior film 50. Furthermore, from the perspective 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, from the perspective of excellent puncture strength and 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 composed of both a stretched polyester resin layer and a stretched polyamide resin layer. From the viewpoint of film strength, the thickness of the base material layer 51 is, for example, preferably 5 μm to 300 μm, and more preferably 5 μm to 150 μm.

[0068] The barrier layer 52 is a layer that at least inhibits the infiltration of moisture. The barrier layer 52 is bonded to the substrate layer 51 via an adhesive layer 54, for example. Examples of the barrier layer 52 include metal foils, vapor-deposited films, and resin layers having barrier properties. Examples of vapor-deposited films include metal vapor-deposited films, inorganic oxide vapor-deposited films, and carbon-containing inorganic oxide vapor-deposited films. Examples of resin layers include polyvinylidene chloride, polymers with chlorotrifluoroethylene (CTFE) as the main component, polymers with tetrafluoroethylene (TFE) as the main component, polymers with fluoroalkyl groups, and polymers with fluoroalkyl units as the main component, and other fluororesins, ethylene-vinyl alcohol copolymers, and the like. In addition, examples of the barrier layer 52 include resin films having at least one of these vapor-deposited films and resin layers. The barrier layer 52 may also be provided in multiple layers. The barrier layer 52 preferably includes a layer composed of a metal material. Specific examples of the metal material constituting the barrier layer 52 include aluminum alloys, stainless steel, titanium steel, and steel plates. When used as a metal foil, it is preferably at least one of aluminum alloy foil and stainless steel foil.

[0069] In the barrier layer 52, the layer composed of the above-mentioned metal material may contain recycled materials of metal materials. As recycled materials of metal materials, for example, recycled materials of aluminum alloy, stainless steel, titanium steel or steel plate can be cited. These recycled materials can be obtained by known methods respectively. Recycled materials of aluminum alloy can be obtained, for example, by the manufacturing method described in International Publication No. 2022 / 092231. The barrier layer 52 may be composed only of recycled materials, or may be composed of a mixture of recycled materials and raw materials. Among them, recycled materials of metal materials refer to various products used in the city, and metal materials that are recycled, separated, refined, etc. from waste discharged from the manufacturing process to become reusable. In addition, the raw materials of metal materials refer to new metal materials refined from natural resources (raw materials) of metals, and are not recycled materials.

[0070] From the perspective of improving the formability of the exterior film 50, the aluminum alloy foil is preferably a soft aluminum alloy foil composed of, for example, an annealed aluminum alloy. From the perspective of further improving formability, an aluminum alloy foil containing iron is preferred. In the aluminum alloy foil containing iron (100% by mass), the iron content is preferably 0.1 to 9.0% by mass, and more preferably 0.5 to 2.0% by mass. An iron content of 0.1% or greater can provide an exterior film 50 with even better formability. An iron content of 9.0% or less can provide an exterior film 50 with even better flexibility. Examples of soft aluminum alloy foil include aluminum alloy foils having compositions specified in JIS H4160: 1994A8021H-O, JIS H4160: 1994A8079H-O, JIS H4000: 2014A8021P-O, or JIS H4000: 2014A8079P-O. Furthermore, silicon, magnesium, copper, manganese, etc. may be added as needed. Softening can be achieved by annealing or the like.

[0071] Examples of the stainless steel foil include austenitic, ferrite, austenitic-ferrite, martensitic, and precipitation-hardened stainless steel foils. Furthermore, from the perspective of providing an exterior film 50 with excellent formability, the stainless steel foil is preferably made of austenitic stainless steel.

[0072] Specific examples of the austenitic stainless steel constituting the stainless steel foil include SUS304, SUS301, and SUS316L. Among them, SUS304 is particularly preferred.

[0073] Regarding the thickness of the barrier layer 52, in the case of metal foil, as long as it functions as a barrier layer that at least inhibits moisture intrusion, it can be, for example, approximately 5 to 200 μm. The thickness of the barrier layer 52 is preferably approximately 85 μm or less, more preferably approximately 50 μm or less, even more preferably approximately 40 μm or less, and particularly preferably approximately 35 μm or less. Furthermore, the thickness of the barrier layer 52 is preferably approximately 10 μm or greater, more preferably approximately 20 μm or greater, and even more preferably approximately 25 μm or greater. Preferred ranges for the thickness of the barrier layer 52 include approximately 10 to 85 μm, approximately 10 to 50 μm, approximately 10 to 40 μm, approximately 10 to 35 μm, approximately 20 to 85 μm, approximately 20 to 50 μm, approximately 20 to 40 μm, approximately 20 to 35 μm, approximately 25 to 85 μm, approximately 25 to 50 μm, approximately 25 to 40 μm, and approximately 25 to 35 μm. When the barrier layer 52 is made of aluminum alloy foil, the above range is particularly preferred. In addition, from the viewpoint of imparting high formability and high rigidity to the exterior film 50, the thickness of the barrier layer 52 is preferably about 35 μm or more, more preferably about 45 μm or more, further preferably about 50 μm or more, further preferably about 55 μm or more, and preferably about 200 μm or less, more preferably about 85 μm or less, further preferably about 75 μm or less, further preferably about 70 μm or less. The preferred range is 35 to 200 μm. The thickness of the outer film 50 is preferably 35 to 85 μm, 35 to 75 μm, 35 to 70 μm, 45 to 200 μm, 45 to 85 μm, 45 to 75 μm, 45 to 70 μm, 50 to 200 μm, 50 to 85 μm, 50 to 75 μm, 50 to 70 μm, 55 to 200 μm, 55 to 85 μm, 55 to 75 μm, and 55 to 70 μm. The outer film 50 has high formability, which facilitates deep drawing and can contribute to a higher capacity of the energy storage device. Furthermore, while the weight of the energy storage device increases when the capacity is increased, increasing the rigidity of the outer film 50 can contribute to a higher sealing performance of the energy storage device. In particular, when the barrier layer 52 is formed of stainless steel foil, the thickness of the stainless steel foil is preferably about 60 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, even more preferably about 30 μm or less, and particularly preferably about 25 μm or less. The thickness of the stainless steel foil is preferably about 10 μm or greater, more preferably about 15 μm or greater. Preferred ranges for the thickness of the stainless steel foil include approximately 10 to 60 μm, approximately 10 to 50 μm, approximately 10 to 40 μm, approximately 10 to 30 μm, approximately 10 to 25 μm, approximately 15 to 60 μm, approximately 15 to 50 μm, approximately 15 to 40 μm, approximately 15 to 30 μm, and approximately 15 to 25 μm.

[0074] In addition, when the barrier layer 52 is an aluminum foil, in order to prevent dissolution, corrosion, etc., it is preferred that a corrosion-resistant film be included on at least the surface opposite to the substrate layer 51. The barrier layer 52 may also include a corrosion-resistant film on both sides. Here, the corrosion-resistant film refers to, for example, the surface of the barrier layer 52 is not subjected to hot water modification treatment such as boehmite treatment, chemical conversion treatment, anodizing treatment, plating treatment with nickel or chromium, etc., or anti-corrosion treatment by coating with a coating agent, so that the barrier layer 52 includes a corrosion-resistant (for example, acid-resistant, alkali-resistant, etc.) film. 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. As a treatment for forming the corrosion-resistant film, one type may be performed, or a combination of two or more types may be performed. In addition, not only one layer but also multiple layers are possible. Among these treatments, hot water reforming and anodizing use a treatment agent to dissolve the surface of the metal foil, forming a metal compound with excellent corrosion resistance. These treatments are sometimes also included in the definition of chemical conversion treatment. Furthermore, if the barrier layer 52 includes a corrosion-resistant film, the barrier layer 52 includes the corrosion-resistant film.

[0075] The corrosion-resistant film prevents delamination between the barrier layer 52 (e.g., aluminum alloy foil) and the substrate layer 51 during the formation of the exterior film 50, and utilizes hydrogen fluoride generated by the reaction of the electrolyte and moisture to prevent the dissolution and corrosion of the surface of the barrier layer 52. In particular, when the barrier layer 52 is an aluminum alloy foil, the film prevents the dissolution and corrosion of aluminum oxide present on the surface of the barrier layer 52, and improves the adhesion (wettability) of the surface of the barrier layer 52, showing the effect of preventing delamination between the substrate layer 51 and the barrier layer 52 during heat sealing and during forming.

[0076] The heat-fusible resin layer 53 is bonded to the barrier layer 52 via, for example, an adhesive layer 55. The heat-fusible 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-fusible resin layer 53 include resin films composed of polyester resins such as polyethylene terephthalate resins and polybutylene terephthalate resins, polyolefin resins such as polyethylene resins and polypropylene resins, cyclic polyolefin resins, or acid-modified polyolefin resins obtained by graft-modifying these polyolefin resins with an acid such as maleic anhydride. From the perspective of sealability and strength, the thickness of the heat-fusible resin layer 53 is preferably 20 to 300 μm, and more preferably 40 to 150 μm.

[0077] The exterior film 50 preferably includes one or more layers having a buffering function (hereinafter referred to as "buffer layer") outside the heat-fusible resin layer 53, more preferably outside the barrier layer 52. The buffer layer can be laminated outside the base layer 51, or the base layer 51 can also function as a buffer layer. When the exterior film 50 includes multiple buffer layers, the multiple buffer layers may be adjacent to each other or laminated with the base layer 51 or the barrier layer 52 interposed therebetween.

[0078] The material constituting the buffer layer can be arbitrarily selected from materials having buffering properties. Examples of materials having buffering properties are rubber, non-woven fabric, or foam sheet. Examples of rubber are natural rubber, fluororubber, or silicone rubber. The rubber hardness is preferably 20 to 90 degrees. The material constituting the non-woven fabric is preferably a material having excellent heat resistance. In the case where the buffer layer is composed of a non-woven fabric, the lower limit of the thickness of the buffer layer is preferably 100 μm, more preferably 200 μm, and more preferably 1000 μm. In the case where the buffer layer is composed of a non-woven fabric, the upper limit of the thickness of the buffer layer is preferably 5000 μm, and more preferably 3000 μm. The preferred range of 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 them, the most preferred range of the thickness of the buffer layer is 1000 μm to 3000 μm.

[0079] When the buffer layer is made of rubber, the lower limit of the buffer layer thickness is preferably 1 mm, more preferably 0.5 mm. When the buffer layer is made of rubber, the upper limit of the buffer layer thickness is preferably 10 mm, more preferably 5 mm, and even more preferably 2 mm. When the buffer layer is made of rubber, the preferred range of the buffer layer thickness is 1 mm to 10 mm, 1 mm to 5 mm, 1 mm to 2 mm, 0.5 mm to 10 mm, 0.5 mm to 5 mm, or 0.5 mm to 2 mm.

[0080] When the exterior film 50 includes a buffer layer, the buffer layer functions as a buffer, thereby suppressing damage to the exterior film 50 due to an impact when the electricity storage device 10 is dropped or due to handling during the manufacture of the electricity storage device 10 .

[0081] In the present embodiment, in a state where the outer film 50 is wound around the electrode body 20 and the reinforcing member 60, the facing surfaces of the outer film 50 (thermo-fusible resin layer 53) are heat-sealed to each other, thereby forming a first sealing portion 70. In the present embodiment, the first sealing portion 70 extends in the longitudinal direction (FB direction) of the outer body 40. In the outer body 40, the position where the first sealing portion 70 is formed can be selected arbitrarily. In the present embodiment, the root 70X of the first sealing portion 70 is preferably located on the edge 43 of the boundary between the first surface 41 and the second surface 42 of the outer body 40. The area of ​​the first surface 41 is larger than the area of ​​the second surface 42. The root 70X of the first sealing portion 70 may also be located on any surface of the outer body 40. In the present embodiment, the first sealing portion 70 is folded, for example, toward the second surface 42 of the outer body 40. When viewed from above, the first sealing portion 70 may extend further outward than the electrode body 20, or may be folded toward the first surface 41.

[0082] The reinforcing member 60 is, for example, rectangular in shape and is made of a resin material. The reinforcing member 60 is a cover that seals the sides of the electrode body 20. Examples of materials for the reinforcing member 60 include polyester resins such as polyethylene terephthalate resins and polybutylene terephthalate resins, polyolefin resins such as polyethylene resins and polypropylene resins, fluororesins, cyclic polyolefin resins, or acid-modified polyolefin resins obtained by grafting these polyolefin resins with acids such as maleic anhydride. The material for the reinforcing member 60 can be selected based on the specific example of the energy storage device 10. If the energy storage device 10 is a lithium-ion secondary battery, the material for the reinforcing member 60 is preferably a material resistant to electrolyte or hydrofluoric acid. If the energy storage device 10 is an all-solid-state battery, the material for the reinforcing member 60 is preferably a material resistant to hydrogen sulfide. Gas absorbents and water absorbents may also be added to the material for the reinforcing member 60 as needed. When a gas absorbent is added to the material constituting the reinforcing member 60, it can absorb gas that is present in the energy storage device 10 and is about to leak out of the energy storage device 10, as well as gas that is about to enter the energy storage device 10 from outside the energy storage device 10. When a water absorbent is added to the material constituting the reinforcing member 60, it can absorb moisture that is present in the energy storage device 10 and is about to leak out of the energy storage device 10, as well as moisture that is about to enter the energy storage device 10 from outside the energy storage device 10. As the water absorbent, any known water absorbent can be used, and an inorganic water absorbent can be preferably used. Preferred specific examples of inorganic water absorbents include calcium oxide, anhydrous magnesium sulfate, magnesium oxide, calcium chloride, zeolite, aluminum oxide, silica gel, aluminum oxide gel, and burnt alum. As the gas absorbent, any known gas absorbent can be used. For example, as the gas absorbent, hydrophobic zeolite having a SiO2 / Al2O3 molar ratio of 1 / 1 to 2000 / 1, bentonite, sepiolite, calcium oxide, copper oxide, or zinc oxide can be cited.

[0083] To ensure proper heat sealing between the reinforcing member 60 and the exterior film 50, the reinforcing member 60 and the heat-fusible resin layer 53 of the exterior film 50 preferably have the same primary material. In this embodiment, the reinforcing member 60 and the heat-fusible resin layer 53 are primarily made of, for example, a polyolefin resin such as a polyethylene resin or a polypropylene resin, or an acid-modified polyolefin resin grafted with an acid such as maleic anhydride. The primary material refers to, for example, a material that accounts for 50% or more of the materials included in the component.

[0084] In addition to being a resin molded product, the reinforcing member 60 may also be a metal molded product. When the reinforcing member 60 is a metal molded product, the material constituting the reinforcing member 60 can be, for example, aluminum, titanium, nickel, copper, stainless steel, iron or titanium materials. When the reinforcing member 60 is a metal molded product or a resin molded product, the reinforcing member 60 preferably has a certain degree of thickness so that even when the storage device 10 is arranged in an overlapping manner, the outer body 40 can be suppressed from deforming. From another perspective, when the reinforcing member 60 is a metal molded product or a resin molded product, when the second sealing portion 80 is formed, the side 60C of the reinforcing member 60 preferably has a certain degree of thickness so that the side 60C of the reinforcing member 60 can be properly heat-sealed with the outer film 50. The minimum value of the thickness of the reinforcing member 60 is, for example, 1.0 mm, more preferably 3 mm, and even more preferably 4 mm. The maximum value of the thickness of the reinforcing member 60 is, for example, 10 mm, more preferably 8.0 mm, and even more preferably 7.0 mm. The maximum value of the thickness of the reinforcing member 60 may also be greater than 10 mm. The preferred range of the thickness of the material of the reinforcing member 60 is 1.0 mm to 10 mm, 1.0 mm to 8.0 mm, 1.0 mm to 7.0 mm, 3.0 mm to 10 mm, 3.0 mm to 8.0 mm, 3.0 mm to 7.0 mm, 4.0 mm to 10 mm, 4.0 mm to 8.0 mm, 4.0 mm to 7.0 mm. In the present invention, when the reinforcing member 60 is a metal molded product or a resin molded product, the material constituting the reinforcing member 60 does not include the film specified by the [Packaging Terms] standard of JIS (Japanese Industrial Standards). The thickness of the reinforcing member 60 may also vary depending on the location of the reinforcing member 60. When the thickness of the reinforcing member 60 varies depending on the location, the thickness of the reinforcing member 60 is the thickness of the thickest part. In addition, the specifications related to these reinforcing members 60 can also be applied similarly to the following variations.

[0085] In this embodiment, from the perspective of appropriately positioning the electrode terminal 30 at a desired position, the reinforcing member 60 includes a first member 61 and a second member 62 that are divided. The first member 61 is positioned above the second member 62. The reinforcing member 60 may also be constructed to include three or more members. When the reinforcing member 60 is composed of multiple divided members, at least two of the members may be made of different materials. The first member 61 and the second member 62 are preferably joined to the electrode terminal 30 via the adhesive film 31 by at least one selected from ultrasonic sealing, high-frequency sealing, heat sealing, hot plate welding, infrared welding, and an adhesive, as needed. Since the electrode terminal 30 is firmly joined to the reinforcing member 60, the reinforcing member 60 can appropriately hold the electrode terminal 30. When the electrode terminal 30 is not joined to the adhesive film 31, the first member 61 and the second member 62 are preferably joined to the electrode terminal 30 by an adhesive. Examples of the adhesive include adhesives used for hot melt or dry lamination.

[0086] The shapes of the first component 61 and the second component 62 can be arbitrarily selected as long as they can sandwich the electrode terminal 30 so that power can be input and output through the electrode terminal 30. The first component 61 and the second component 62 preferably have substantially the same shape. In this embodiment, the length of the first component 61 in the UD direction is longer than the length of the second component 62 in the UD direction. Therefore, the electrode terminal 30 is located below the center of the reinforcing component 60 in the UD direction. The electrode terminal 30 may also be located at the center of the reinforcing component 60 in the UD direction or above the center.

[0087] like Figure 4 As shown, the reinforcing member 60 has a first surface 60A facing the electrode body 20 in the state where the first member 61 and the second member 62 are combined, a second surface 60B opposite to the first surface 60A, and a side surface 60C connecting the first surface 60A and the second surface 60B.

[0088] like Figure 5 As shown, in the present embodiment, the second sealing portion 80 is formed by heat-sealing the outer film 50 to the second surface 60B and the side surface 60C of the reinforcing member 60. Furthermore, in the present embodiment, from the viewpoint of improving the airtightness of the outer body 40, the terminal sealing portion 90 is formed by joining the outer film 50 to the exposed portion 30A of the electrode terminal 30. In the terminal sealing portion 90, the outer film 50 and the exposed portion 30A are joined via the adhesive film 31 as needed. In addition, in the present embodiment, it is sufficient to form at least the terminal sealing portion 90 out of the second sealing portion 80 and the terminal sealing portion 90. In other words, in the present embodiment, at least one of the second surface 60B and the side surface 60C of the reinforcing member 60 may not be joined to the outer film 50.

[0089] <1-2. Method for manufacturing an electricity storage device>

[0090] Figure 6 This is a flowchart illustrating an example of a method for manufacturing the energy storage device 10. The method for manufacturing the energy storage device 10 includes, for example, a first step, a second step, a third step, a fourth step, a fifth step, a sixth step, a seventh step, an eighth step, and a ninth step. The first through ninth steps are performed, for example, by an apparatus for manufacturing the energy storage device 10. In this embodiment, the names of the first through ninth steps are given for convenience and do not imply a specific order of the steps.

[0091] In the first process of step S11 , the manufacturing apparatus manufactures the first member 61 and the second member 62 .

[0092] The second step of step S12 is performed after the first step. In the second step, the manufacturing apparatus joins the adhesive film 31 to the electrode terminal 30. Alternatively, the second step may be performed before the first step.

[0093] The third step (connection step) of step S13 is performed after the second step. In the third step, the manufacturing apparatus connects the electrode terminal 30 to the current collector 20X, thereby electrically connecting the electrode terminal 30 to the electrode of the electrode body 20. Alternatively, the third step may be performed before the second step.

[0094] The fourth step (arrangement step) of step S14 is performed after the first, second, or third steps. In the fourth step, the manufacturing device sandwiches the electrode terminal 30 between the first member 61 and the second member 62. The manufacturing device joins the first member 61 and the second member 62 to the electrode terminal 30 using at least one method selected from ultrasonic sealing, high-frequency sealing, heat sealing, hot plate welding, infrared welding, and adhesives. The fourth step is completed, and the electrode terminal 30 is joined to the reinforcing member 60.

[0095] The fifth step (packaging process) of step S15 is performed after the fourth step. In the fifth step, the manufacturing apparatus packages the electrode assembly 20 and the reinforcing member 60 with the exterior film 50 .

[0096] The sixth process of step S16 is implemented after the fifth process. In the fifth process, the manufacturing device forms a first sealing portion 70 (hereinafter referred to as a "temporary first sealing portion") having an unsealed portion in a portion by heat-sealing the relative heat-fusible resin layers 53 of the outer film 50. In addition, the unsealed portion can be formed, for example, by using a sealing strip having a shape in which a portion does not contact the outer film 50. In another example, the unsealed portion can be formed by sandwiching a fluororesin film or the like between the facing surfaces (heat-fusible resin layers 53) of the outer film 50. By forming the temporary first sealing portion before the second sealing portion 80 and the terminal sealing portion 90, the outer film 50 can be used to hold the electrode body 20, so the position of the electrode body 20 relative to the outer film 50 is not easily shifted. Therefore, when the second sealing portion 80 and the terminal sealing portion 90 are formed, the generation of wrinkles can be suppressed.

[0097] The seventh step of step S17 is performed after the sixth step. In the seventh step, the manufacturing apparatus heat-seals the exterior film 50 and the second surface 60B and the side surface 60C of the reinforcing member 60 to form the second sealed portion 80 .

[0098] The eighth step (sealing step) of step S18 is performed after the seventh step. In the eighth step, the manufacturing apparatus heat-seals the exterior film 50 and the exposed portion 30A of the electrode terminal 30 to form the terminal sealing portion 90. Alternatively, the eighth step may be performed before the seventh step.

[0099] The ninth step of step S19 is performed after the seventh or eighth step. In the ninth step, the manufacturing apparatus injects an electrolyte solution into the unsealed portion of the temporary first sealed portion, evacuates the outer film 50, and then heat-seals the unsealed portion to form the first sealed portion 70. If the energy storage device 10 is an all-solid-state battery, the electrolyte injection step is omitted in the ninth step.

[0100] <1-3. Functions and Effects of Energy Storage Devices>

[0101] According to the electricity storage device 10, since the terminal sealing portion 90 is provided, even if gaps exist between the electrode assembly 20 and the first and second members 61 and 62 of the reinforcing member 60, the gaps are sealed by the exterior film 50. Therefore, the sealing performance of the electricity storage device 10 is improved.

[0102] [2. First Modification of the Embodiment]

[0103] A first modified example of the embodiment (hereinafter referred to as "first modified example") differs from the embodiment in that it includes a reinforcing member 260. The remaining structure is the same as the embodiment. The following description of the first modified example of the embodiment's energy storage device 210 focuses on the differences from the embodiment.

[0104] <2-1. Structure of the Energy Storage Device>

[0105] Figure 7 This is a cross-sectional view of the energy storage device 210 of the first variant. The energy storage device 210 includes a reinforcing member 260. The reinforcing member 260 is a cover that seals the side of the electrode body 20. The reinforcing member 260 includes a first member 261 and a second member 262 that are divided. The first member 261 is arranged above the second member 262. The reinforcing member 260 has a first surface 260A facing the electrode body 20 when the first member 261 and the second member 262 are combined, a second surface 260B opposite to the first surface 260A, and a side surface 260C connecting the first surface 260A and the second surface 260B.

[0106] In the first variant, from the perspective of shortening the distance between the reinforcing member 260 and the electrode body 20 in the FB direction, the reinforcing member 260 has a recess 260X that accommodates at least a portion of the current collector 20X. In the first variant, the recess 260X has a size that can accommodate approximately the entirety of the current collector 20X. The recess 260X is recessed from the first surface 260A toward the second surface 260B. The recess 260X does not penetrate the first surface 260A and the second surface 260B. The depth LA of the recess 260X in the FB direction can be arbitrarily selected. From the perspective of accommodating more current collectors 20X, the additional depth LA is preferably more than half the length of the side surface 260C in the FB direction.

[0107] <2-2. Functions and Effects of Energy Storage Devices>

[0108] The energy storage device 210 of the first modified example can achieve the same functions and effects as the energy storage device 10 of the embodiment. Furthermore, the energy storage device 210 accommodates at least a portion of the current collector 20X in the recess 260X of the reinforcing member 260, thereby shortening the distance between the reinforcing member 260 and the electrode assembly 20 in the FB direction. Consequently, the energy storage device 210 can be constructed in a compact size.

[0109] [3. Second Modification of the Embodiment]

[0110] A second modified example of the embodiment (hereinafter referred to as "second modified example") differs from the embodiment in that it includes a reinforcing member 360. The remaining structure is the same as the embodiment. The following description of the second modified example of the embodiment's energy storage device 310 focuses on the differences from the embodiment.

[0111] <3-1. Structure of the Energy Storage Device>

[0112] Figure 8It is a cross-sectional view of the energy storage device 310 of the second modified example. The energy storage device 310 includes a reinforcing member 360. The reinforcing member 360 is a cover that seals the side of the electrode body 20. Depending on the shape of the reinforcing member 360, the electrode body 20 may not be properly sealed due to damage to the outer film 50 or wrinkles on the outer film 50. The energy storage device 310 of the second modified example is configured to be able to properly seal the electrode body 20. The reinforcing member 360 has a divided first part 361 and a second part 362. The first part 361 is arranged above the second part 362. The reinforcing member 360 has a first surface 360A facing the electrode body 20 when the first part 361 and the second part 362 are combined, a second surface 360B opposite to the first surface 360A, and a side surface 360C connecting the first surface 360A and the second surface 360B.

[0113] The second surface 360B is divided into a first inclined surface 360BX formed on the first part 361 and a second inclined surface 360BY formed on the second part 362. The first inclined surface 360BX and the second inclined surface 360BY extend in a direction opposite to the electrode body 20. The first inclined surface 360BX and the second inclined surface 360BY are inclined toward the center of the height direction (UD direction) of the reinforcing part 360 as they go in a direction opposite to the electrode body 20. In other words, the first inclined surface 360BX and the second inclined surface 360BY are inclined toward the electrode terminal 30 as they go in a direction opposite to the electrode body 20. Therefore, the first inclined surface 360BX and the second inclined surface 360BY approach each other as they go in a direction opposite to the electrode body 20. Since the area of ​​the second surface 360B is large, in the second sealing portion 80, most of the exterior film 50 is bonded to the second surface 60B. Therefore, the sealing performance of the electricity storage device 310 is improved.

[0114] In the second modification, the angle formed between the first inclined surface 360BX and the second inclined surface 360BY and the side surface 360C exceeds 90 degrees to prevent damage to the exterior film 50 and wrinkles in the second sealing portion 80. Furthermore, in the energy storage device 310 of the second modification, the terminal sealing portion 90 can be omitted.

[0115] <3-2. Functions and Effects of Energy Storage Devices>

[0116] The energy storage device 310 of the second modified example achieves the same functions and effects as the energy storage device 10 of the embodiment. Furthermore, in the energy storage device 310, the angle formed between the first inclined surface 360BX and the second inclined surface 360BY and the side surface 360C exceeds 90 degrees. Since the corner at the boundary between the side surface 360C and the second surface 360B is an obtuse angle, damage to the exterior film 50 can be suppressed. Furthermore, wrinkles in the exterior film 50 during the formation of the second sealing portion 80 can be suppressed.

[0117] [4. Third Modification of the Embodiment]

[0118] A third modified example of the embodiment (hereinafter referred to as "third modified example") differs from the embodiment in that it includes a reinforcing member 460. The remaining structure is the same as the embodiment. The following description of the third modified example of the embodiment's energy storage device 410 focuses on the differences from the embodiment.

[0119] <4-1. Structure of the Energy Storage Device>

[0120] Figure 9 It is a perspective view of a reinforcing member 460 included in an electric storage device 410 according to a third modification. Figure 10 is a cross-sectional view of the power storage device 410 . Figure 11 yes Figure 10 A cross-sectional view of an energy storage device 410 in a state where the internal pressure of the outer casing 40 has increased. Due to prolonged use of the energy storage device 410, the internal pressure of the outer casing 40 may increase due to at least one of gas generation and expansion of the electrode body 20. When the internal pressure of the outer casing 40 increases, the outer film 50 may peel off from the reinforcing member 460. If the outer film 50 peels off from the reinforcing member 460, the electrode body 20 may not be properly sealed. The energy storage device 410 of the third modified example is configured to properly seal the electrode body 20.

[0121] like Figure 9 As shown, the reinforcing member 460 includes a first member 461 and a second member 462 that are divided. The reinforcing member 460 is a cover that seals the sides of the electrode body 20. The first member 461 is positioned above the second member 462. The reinforcing member 460 includes a first surface 460A that faces the electrode body 20 when the first member 461 and the second member 462 are combined, a second surface 460B that is opposite to the first surface 460A, and a side surface 460C that connects the first surface 460A and the second surface 460B.

[0122] The first member 461 includes a main body 461X and a movable portion 461Y movable relative to the main body 461X. The second member 462 includes a main body 462X and a movable portion 462Y movable relative to the main body 462X. The main bodies 461X and 462X constitute the first surface 460A, the second surface 460B, and the side surface 460C.

[0123] When the exterior film 50 expands as the electrode assembly 20 expands, the movable portions 461Y and 462Y move relative to the main portions 461X and 462X. The movable portion 461Y is connected to the main portion 461X only at the upper end of the first surface 460A. The movable portion 462Y is connected to the main portion 462X only at the lower end of the first surface 460A. The main portions 461X and 462X and the movable portions 461Y and 462Y may be integrally formed or may be separate and joined.

[0124] The shape of the movable parts 461Y and 462Y can be arbitrarily selected as long as it is a shape that can be movable relative to the main parts 461X and 462X. In the third modified example, the movable parts 461Y and 462Y are in the shape of a triangular prism extending in the LR direction. In the LR direction, the relationship between the length of the movable parts 461Y and 462Y and the length of the main parts 461X and 462X can be arbitrarily selected. In the third modified example, in the LR direction, the length of the movable parts 461Y and 462Y is substantially equal to the length of the main parts 461X and 462X. In the LR direction, the length of the movable parts 461Y and 462Y may be shorter than the length of the main parts 461X and 462X. The movable parts 461Y and 462Y only need to be provided at at least one of the corners of the main parts 461X and 462X in the first surface 460A.

[0125] The upper surface 461YX of the movable portion 461Y is bonded, for example, by heat sealing to the exterior film 50. The lower surface 462YX of the movable portion 462Y is bonded, for example, by heat sealing to the exterior film 50. In the power storage device 410 of the third modification, the terminal sealing portion 90 can also be omitted.

[0126] <4-2. Functions and Effects of Energy Storage Devices>

[0127] According to the electricity storage device 410 of the third modification, in addition to the same operations and effects as those of the electricity storage device 10 of the embodiment, the following operations and effects can be obtained.

[0128] like Figure 11As shown, the storage device 410 generates at least one of gas and expansion of the electrode body 20 due to long-term use, thereby sometimes causing the internal pressure of the outer body 40 to rise. In a typical example, the outer body 40 and the electrode body 20 expand significantly in the UD direction. For example, due to the expansion of the electrode body 20, the outer film 50 is pressed by the electrode body 20. The upper surface 461YX of the movable part 461Y is joined to the outer film 50. Therefore, as the internal pressure of the outer body 40 rises, the movable part 461Y rotates relative to the main body 461X in a manner separated from the first surface 460A with the upper end of the first surface 460A as the rotation center. The lower surface 462YX of the movable part 462Y is joined to the outer film 50. Therefore, as the internal pressure of the outer body 40 rises, the movable part 462Y rotates relative to the main body 462X in a manner separated from the first surface 460A with the lower end of the first surface 460A as the rotation center. According to the electricity storage device 410 , even when the internal pressure of the exterior body 40 increases, it is possible to suppress the exterior film 50 from being peeled off from the reinforcing member 460 .

[0129] [5. Fourth Modification of the Implementation Method]

[0130] A fourth modified example of the embodiment (hereinafter referred to as "the fourth modified example") differs from the embodiment in that it includes a reinforcing member 560. The remaining structure is the same as the embodiment. The following description of the fourth modified example of the embodiment's energy storage device 510 focuses on the differences from the embodiment.

[0131] <5-1. Structure of the Energy Storage Device>

[0132] Figure 12 It is a perspective view of a reinforcing member 560 included in an electric storage device 510 according to a fourth modification. Figure 13 is a cross-sectional view of the power storage device 510 .

[0133] like Figure 12 As shown, the reinforcing member 560 is, for example, plate-shaped and has a first surface 560A facing the electrode body 20 , a second surface 560B opposite to the first surface 560A, and a side surface 560C connecting the first surface 560A and the second surface 560B.

[0134] A hole 560X is formed in the center of the reinforcing member 560, penetrating the first surface 560A and the second surface 560B. The size of the hole 560X is slightly larger than the electrode terminal 30. In the fourth modification, in the fourth step of the manufacturing method of the power storage device 510 (see Figure 6), the electrode terminal 30 connected to the electrode body 20 is inserted into the hole 560X of the reinforcing member 560. In the fourth modification, if a gap is formed between the adhesive film 31 and the hole 560X, the gap is preferably filled with a resin material such as a hot melt or welding. Furthermore, in the energy storage device 510 of the fourth modification, the terminal sealing portion 90 can be omitted.

[0135] The energy storage device 510 of the fourth modification can achieve the same functions and effects as the energy storage device 10 of the embodiment. Furthermore, in the energy storage device 510, since the reinforcement member 560 is not divided, the strength of the reinforcement member 560 is high. Therefore, even when stress is applied to the reinforcement member 560 due to vibration or the like, damage to the reinforcement member 560 can be suppressed.

[0136] [6. Fifth Modification of the Embodiment]

[0137] The energy storage device 610 of the fifth modified example of the embodiment (hereinafter referred to as the "fifth modified example") differs from the embodiment in that it includes a reinforcing member 660. The remaining structure is the same as the embodiment. The following description of the energy storage device 610 of the fifth modified example focuses on the differences from the embodiment.

[0138] <6-1. Structure of the power storage device>

[0139] Figure 14 It is a perspective view of a reinforcing member 660 included in an electricity storage device 610 according to a fifth modification. Figure 15 is a cross-sectional view of the power storage device 610 .

[0140] like Figure 14 As shown, the reinforcing member 660 is a frame having a first surface 660A facing the electrode body 20 , a second surface 660B opposite to the first surface 660A, and a side surface 660C connecting the first surface 660A and the second surface 660B.

[0141] A hole 660X is formed in the center of the reinforcing member 660, penetrating the first surface 660A and the second surface 660B. The hole 660X is sufficiently large relative to the electrode terminal 30. The interior of the hole 660X forms a space 660Y in which at least a portion of the current collector 20X is disposed. In the fifth modification, substantially the entire current collector 20X is disposed within the space 660Y.

[0142] In the fifth modification, in the fourth step of the method for manufacturing the power storage device 610 (see Figure 6), the electrode terminal 30 connected to the electrode body 20 is inserted into the hole 660X of the reinforcing member 660. In the fifth modification, the hole 660X is sufficiently large relative to the electrode terminal 30, so that in the fourth step, the reinforcing member 660 and the electrode terminal 30 are not joined. Therefore, in the second step of the manufacturing method of the power storage device 610 (see Figure 6 ), it is preferable that the adhesive film 31 be bonded only to the portion of the electrode terminal 30 that is bonded to the exterior film 50. Furthermore, in the power storage device 610 of the fifth modification, the terminal sealing portion 90 can also be omitted.

[0143] <6-2. Functions and Effects of Energy Storage Devices>

[0144] The energy storage device 610 of the fifth modification can achieve the same functions and effects as the energy storage device 10 of the embodiment. Furthermore, in the energy storage device 610, since at least a portion of the current collector 20X is accommodated in the space 660Y of the reinforcing member 660, the distance between the reinforcing member 660 and the electrode assembly 20 in the FB direction can be shortened. Consequently, the energy storage device 610 can be constructed in a compact size.

[0145] [7. Sixth Modification of the Implementation Method]

[0146] A sixth modified example of the embodiment (hereinafter referred to as "sixth modified example") differs from the embodiment in that it includes a reinforcing member 760. The remaining structure is the same as the embodiment. The following description of the sixth modified example of the embodiment's energy storage device 710 focuses on the differences from the embodiment.

[0147] <7-1. Structure of the Energy Storage Device>

[0148] Figure 16 It is a cross-sectional view of the energy storage device 710 of the sixth variant. The reinforcing member 760 includes a first member 761 and a second member 762 that are divided. The reinforcing member 760 is a cover that seals the side of the electrode body 20. Depending on the shape of the reinforcing member 760, stress is concentrated on the interface between the reinforcing member 760 and the electrode body 20, and the outer film 50 may be damaged. In the case where the outer film 50 is damaged, the electrode body 20 cannot be properly sealed. The energy storage device 710 of the sixth variant is configured to be able to properly seal the electrode body 20. The first member 761 is arranged above the second member 762. The reinforcing member 760 has a first surface 760A facing the electrode body 20 when the first member 761 and the second member 762 are combined, a second surface 760B opposite to the first surface 760A, and a side surface 760C connecting the first surface 760A and the second surface 760B.

[0149] The first member 761 includes a main body 761X and an extension 761Y extending from the main body 761X toward the electrode body 20. The second member 762 includes a main body 762X and an extension 762Y extending from the main body 762X toward the electrode body 20. The main bodies 761X and 762X define the first surface 760A, the second surface 760B, and the side surface 760C. The main bodies 761X and 762X and the extensions 761Y and 762Y may be integrally formed or may be formed separately and joined together.

[0150] The extension portion 761Y extends from a portion including the upper end of the first surface 760A toward the electrode body 20. The extension portion 761Y has a shape in which the front end becomes thinner as it moves toward the electrode body 20. Preferably, the upper surface 761YX of the extension portion 761Y is bonded to the outer film 50, for example, by heat bonding. Since a larger area of ​​the reinforcing member 760 is bonded to the outer film 50, the reinforcing member 760 is more firmly bonded to the outer film 50. The upper surface 761YX does not have to be bonded to the outer film 50. The front end of the extension portion 761Y covers a portion of the electrode body 20.

[0151] The extension portion 762Y extends from a portion including the lower end of the first surface 760A toward the electrode body 20. The extension portion 762Y has a shape in which the front end becomes thinner as it goes toward the electrode body 20. Preferably, the lower surface 762YX of the extension portion 762Y is bonded to the outer film 50, for example, by heat bonding. Since a larger area of ​​the reinforcing member 760 is bonded to the outer film 50, the reinforcing member 760 is more firmly bonded to the outer film 50. The lower surface 762YX does not have to be bonded to the outer film 50. The front end of the extension portion 762Y covers a portion of the electrode body 20.

[0152] The relationship between the length of the extensions 761Y and 762Y and the length of the main bodies 761X and 762X in the LR direction can be arbitrarily selected. In the sixth modification, the length of the extensions 761Y and 762Y in the LR direction is substantially equal to the length of the main bodies 761X and 762X. The length of the extensions 761Y and 762Y in the LR direction may also be shorter than the length of the main bodies 761X and 762X. Furthermore, in the sixth modification, the terminal seal 90 may be omitted.

[0153] <7-2. Functions and Effects of Energy Storage Devices>

[0154] The energy storage device 710 of the sixth modification can achieve the same functions and effects as the energy storage device 10 of the embodiment. Furthermore, in the energy storage device 710, the extensions 761Y and 762Y taper toward the electrode body 20, thereby suppressing stress concentration at the interface between the reinforcing member 760 and the electrode body 20. Consequently, damage to the exterior film 50 can be suppressed.

[0155] [8. Seventh Modification of the Embodiment]

[0156] A seventh modified example of the embodiment (hereinafter referred to as "the seventh modified example") differs from the embodiment in that it includes a buffer film 820. The remaining structure is the same as the embodiment. The following description of the seventh modified example of the embodiment's energy storage device 810 focuses on the differences from the embodiment.

[0157] <8-1. Structure of the power storage device>

[0158] Figure 17 It is a cross-sectional view of the energy storage device 810 of the seventh variant. When the strength of the outer film 50 is low, pinholes may be generated in the outer film 50. When pinholes are generated in the outer film 50, the electrode body 20 cannot be properly sealed. The energy storage device 810 of the seventh variant is configured to be able to properly seal the electrode body 20. The energy storage device 810 has a buffering film 820 for increasing the strength of the outer film 50. The buffering film 820 is arranged on the inner side of the outer film 50. In order to suppress the generation of pinholes in the outer film 50, the buffering film 820 is arranged at least one of the corners of the electrode body 20 and the corners of the reinforcing member 60. In the seventh variant, the buffering film 820 is arranged at all corners of the electrode body 20 and all corners of the reinforcing member 60. The material constituting the buffering film 820 is, for example, a polyester material, a polyolefin material, or a fluorine material. In addition, in the energy storage device 810 of the seventh variant, the terminal sealing portion 90 can also be omitted.

[0159] <8-2. Functions and Effects of Energy Storage Devices>

[0160] The seventh modified example of the energy storage device 810 can achieve the same functions and effects as the energy storage device 10 of the embodiment. Furthermore, the energy storage device 810 includes the buffer film 820, which improves the strength of the exterior film 50. This prevents the formation of pinholes in the exterior film 50.

[0161] [9. Eighth Modification of the Embodiment]

[0162] An energy storage device 910 according to an eighth variation of the embodiment (hereinafter referred to as "eighth variation") differs from the embodiment in that it includes an exterior film 950. The remaining configuration is the same as the embodiment. The following description of energy storage device 910 according to the eighth variation focuses on the differences from the embodiment.

[0163] <9-1. Structure of the power storage device>

[0164] Figure 18It is a cross-sectional view of an electrical storage device 910 according to the eighth variant. The electrical storage device 910 includes an outer film 950. When the internal pressure of the outer casing 40 rises, the outer film 950 may peel off from the reinforcing member 60. When the outer film 950 peels off from the reinforcing member 60, the electrode body 20 cannot be properly sealed. The electrical storage device 910 according to the eighth variant is configured to properly seal the electrode body 20. The outer film 950 has an expansion portion 951 located between the electrode body 20 and the reinforcing member 60. The expansion portion 951 is configured to be able to bulge when the outer casing 40 expands as the internal pressure of the outer casing 40 rises. The shape of the expansion portion 951 can be arbitrarily selected as long as it is a shape that can bulge. In the eighth variant, the expansion portion 951 is a curved shape that is recessed toward the electrode terminal 30. The expansion portion 951 may be a corner that is recessed toward the electrode terminal 30 or may be a corrugated shape. The swollen portion 951 does not need to be concave, and may be a portion that is flexible enough to swell. In the electricity storage device 910 of the eighth modification, the terminal sealing portion 90 may also be omitted.

[0165] <9-2. Functions and Effects of Energy Storage Devices>

[0166] The eighth modified example of the energy storage device 910 provides the same functions and effects as the energy storage device 10 of the embodiment. Furthermore, the energy storage device 910 includes the expansion portion 951 on the exterior film 50, thereby preventing the exterior film 950 from peeling off from the reinforcing member 60 even when the internal pressure of the exterior body 40 increases.

[0167] [10. Other Modifications]

[0168] The above-mentioned embodiments and modifications are examples of possible forms of the storage device, reinforcement component, and method for manufacturing the storage device of the present invention, and are not intended to limit their forms. The storage device, reinforcement component, and method for manufacturing the storage device of the present invention can adopt forms different from those illustrated in the embodiments and modifications. One example is a form in which a part of the structure of the embodiments and modifications is replaced, changed, or omitted, or a form in which a new structure is added to the embodiments and modifications. Several examples of other modifications of the embodiments and modifications are shown below. In addition, the above-mentioned embodiments and modifications, as well as the other modifications below, can be combined with each other as long as they are not technically inconsistent.

[0169] <10-1>

[0170] In the electricity storage device 10 of the embodiment, the reinforcing member 60 may not be divided into the first member 61 and the second member 62. In this modification, Figure 6In the manufacturing method of the energy storage device 10 shown, the first step can be omitted. In the fourth step, the reinforcing member 60 is insert-molded with the electrode terminal 30 connected to the electrode body 20 (the reinforcing member 60 is arranged by insert molding). In addition, in the fourth step, a heat insulating material for protecting the electrode body 20 is preferably arranged between the electrode body 20 and the portion forming the reinforcing member 60. The heat insulating material is preferably removed after the fourth step. This modification can also be similarly applied to the fourth modification.

[0171] <10-2>

[0172] In the energy storage device 10 of the embodiment, one of the two electrode terminals 30 does not need to be bonded to the exterior film 50. In other words, one of the two electrode terminals 30 does not need to have the terminal sealing portion 90. For example, one of the two electrode terminals 30 that does not have the terminal sealing portion 90 may simply have the second sealing portion 80. In short, the energy storage device 10 only needs to have at least one terminal sealing portion 90. Furthermore, in the first to eighth variations, both terminal sealing portions 90 may be omitted.

[0173] <10-3>

[0174] In the energy storage device 10 of the embodiment, the two electrode terminals 30 may protrude from one of the two reinforcing members 60. In this variation, the portion of the exterior body 40 where the other reinforcing member 60 is located can be sealed using a known method. For example, the portion where the other reinforcing member 60 is located may be sealed using a known single-piece reinforcing member. Alternatively, the other reinforcing member 60 may be omitted, and the electrode body 20 may be sealed by folding the exterior film 50. This variation is also applicable to the first to eighth variations.

[0175] <10-4>

[0176] In the power storage device 10 of the embodiment, the outer film 50 can be a laminate (laminated film) having a heat-fusible resin layer 53 on both sides of the barrier layer 52. In this modification, the first sealing portion 70 can be formed by heat-sealing the heat-fusible resin layers 53 stacked on one side or the other side relative to the barrier layer 52, or can be formed by heat-sealing the heat-fusible resin layer 53 stacked on one side relative to the barrier layer 52 and the heat-fusible resin layer 53 stacked on the other side. In this modification, the root 70X of the first sealing portion 70 is located on any surface of the outer body 40. In this modification, the root 70X of the first sealing portion 70 is preferably located near the edge 43 of the boundary between the first surface 41 and the second surface 42. In this modification, the heat-fusible resin layer 53 can also be bonded to the barrier layer 52 via an adhesive layer 55, for example. This modification can also be applied to the first to eighth modifications in the same manner.

[0177] <10-5>

[0178] In the electricity storage device 10 according to the embodiment, the outer shape of the exterior body 40 can be arbitrarily changed. Figure 19 It is a plan view of an electric storage device 10 according to a modification. Figure 20 yes Figure 19 1 is a side view of the power storage device 10.

[0179] In the energy storage device 10 of this modified example, the exterior film 50 is wound around the electrode body 20, with an extension portion 70Y extending outward from the electrode body 20. While the exterior film 50 is wound around the electrode body 20 with the extension portion 70Y, the facing surfaces (thermo-fusible resin layers 53) of the exterior film 50 are heat-sealed to form a sealed portion 60Y. In this modified example, the extension portion 70Y includes a first extension portion 71Y and a second extension portion 72Y. The electrode body 20 and the reinforcing member 60 are positioned between the first extension portion 71Y and the second extension portion 72Y.

[0180] The first extension portion 71Y is opposite to the second extension portion 72Y via the electrode body 20 and the reinforcing member 60. The first extension portion 71Y has a pair of side portions 71A and 71B in the short side direction of the outer body 40 when viewed from above. The second extension portion 72Y has a pair of side portions 72A and 72B in the short side direction of the outer body 40 when viewed from above. In this modification, the side portions 71A, 71B, 72A, and 72B are folded inwardly in a manner that the heat-fusible resin layer (inner surface) of the outer film 50 is opposite to each other. In other words, the side portions 71A, 71B, 72A, and 72B are folded inwardly in a manner that the base material layer 51 (outer surface) of the outer film 50 is opposite to each other. In this modification, the outer body 40 is a so-called gable top type bag.

[0181] The sealing portion 60Y includes a first extending sealing portion 91Y and a second extending sealing portion 92Y. The first extending sealing portion 91Y is formed on the first extending portion 71Y. The first extending sealing portion 91Y extends in the short side direction of the outer body 40. The first extending sealing portion 91Y includes a pair of side sealing portions 91YA and a central sealing portion 91YB. The pair of side sealing portions 91YA are portions where the heat-fusible resin layers 53 in the folded pair of side portions 71A and 71B are heat-sealed to each other. The central sealing portion 91YB is a portion located between the pair of side sealing portions 91YA. The central sealing portion 91YB is sealed while sandwiching the electrode terminal 30. The portion where the first extending portion 71Y in the outer film 50 is joined to the electrode terminal 30 constitutes the terminal sealing portion 90.

[0182] The second extending seal portion 92Y is formed in the second extending portion 72Y. The second extending seal portion 92Y extends in the short side direction of the outer body 40. The second extending seal portion 92Y includes a pair of side seal portions 92YA and a central seal portion 92YB. The pair of side seal portions 92YA are portions where the heat-fusible resin layers in the pair of side portions 72A and 72B after folding are heat-sealed to each other. The central seal portion 92YB is a portion located between the pair of side seal portions 92YA. The central seal portion 92YB is sealed while sandwiching the two electrode terminals 30. The portion where the second extending portion 72Y in the outer film 50 is joined to the electrode terminal 30 constitutes the terminal seal portion 90.

[0183] Figure 21 It is a top view of the energy storage device 10 of another modified example of the embodiment. The energy storage device 10 of this modified example has an extension portion 270Y. The extension portion 270Y includes a first extension portion 271Y and a second extension portion 272Y that are opposite to each other across the electrode body 20 and the reinforcing member 60. The first extension portion 271Y has a pair of side portions 271A and 271B in the short side direction of the outer casing 40 when viewed from above. The second extension portion 272Y has a pair of side portions 272A and 272B in the short side direction of the outer casing 40 when viewed from above. In this modified example, the side portions 271A, 271B, 272A, and 272B are opposite to each other. Figure 19 Unlike the modified examples shown in FIG. 1 , the outer film 50 is not folded inwardly so that the inner surfaces of the outer film 50 face each other. The width XA of the extended portion 270 in the expanded state is wider than the width XB of the electrode body 20. In this modified example, the outer body 40 is a so-called square-shaped bag.

[0184] The protruding seal portion 290Y includes a first protruding seal portion 291Y and a second protruding seal portion 292Y. The first protruding seal portion 291Y is formed on the first protruding portion 271Y. The first protruding seal portion 291 extends in the short side direction of the outer body 40. The first protruding seal portion 291Y includes a pair of side seal portions 291A and a central seal portion 291B. The pair of side seal portions 291A are portions of the outer film 50 where the heat-fusible resin layers 53 are heat-sealed to each other at the portions located outside the end portions in the width direction of the electrode body 20. The central seal portion 291B is a portion located between the pair of side seal portions 291A. The central seal portion 291B is sealed while sandwiching the electrode terminal 30. The portion of the outer film 50 where the first protruding portion 271Y is joined to the electrode terminal 30 constitutes the terminal seal portion 90.

[0185] The second extended seal portion 292Y is formed in the second extended portion 272Y. The second extended seal portion 292Y extends in the short side direction of the outer body 40. The second extended seal portion 292Y includes a pair of side seal portions 292A and a central seal portion 292B. The pair of side seal portions 292A are portions of the outer film 50 where the heat-fusible resin layers 53 located outside the end portion in the width direction of the electrode body 20 are heat-sealed to each other. The central seal portion 292B is a portion located between the pair of side seal portions 292A. The central seal portion 292B is sealed in a state of sandwiching the two electrode terminals 30. The portion where the second extended portion 272Y in the outer film 50 is joined to the electrode terminal 30 constitutes the terminal seal portion 90. In addition, Figures 19 to 21 The related modification examples can also be applied similarly to the first modification example to the eighth modification example.

[0186] <10-6>

[0187] In the electricity storage device 10 of the embodiment, the electrode assembly 20 and the reinforcing member 60 are packaged by winding one outer film 50, but they may be packaged by joining two or more outer films 50. This modification is also applicable to the first to eighth modifications.

[0188] <10-7>

[0189] In the energy storage device 10 of the embodiment, to more appropriately bond the reinforcing member 60 and the exterior film 50, the reinforcing member 60 and the exterior film 50 may be bonded via an adhesive film. The adhesive film in this modification has the same specifications as the adhesive film 31. In particular, when the reinforcing member 60 is made of a metal, it is preferable to bond the reinforcing member 60 and the exterior film 50 via the adhesive film. This modification is also applicable to the first to eighth modifications.

[0190] <10-8>

[0191] In the energy storage device 10 of the embodiment, the reinforcing member 60 is made of a resin material, but the reinforcing member 60 may also be made of other materials. The reinforcing member 60 may also be made of, for example, ceramics or glass. Examples of ceramics include alumina, zirconia, silicon carbide, forsterite, silicon nitride, steatite, cordierite, sialon, ferrite, barium titanate, and mullite.

[0192] Description of Reference Numerals

[0193] 10, 210, 310, 410, 510, 610, 710, 810, 910: Energy storage devices

[0194] 20: Electrode body

[0195] 20X: Current collector

[0196] 30: Electrode terminal

[0197] 30A: Exposed part

[0198] 50, 950: Exterior film

[0199] 60, 260, 360, 460, 560, 660, 760: Reinforced components

[0200] 61, 261, 361, 461, 761: Part 1

[0201] 62, 262, 362, 462, 762: Part 2

[0202] 260X: Concave

[0203] 360B: Side 2

[0204] 461X, 462X: Main body

[0205] 461Y, 462Y: movable parts

[0206] 560X, 660X: hole

[0207] 660Y: Space

[0208] 761X, 762X: Main body

[0209] 761Y, 762Y: extension

[0210] 820: Buffering film

[0211] 951: Expansion section.

Claims

1. An electric storage device comprising: Electrode body; an electrode terminal electrically connected to the electrode body; a reinforcing member disposed on a side of the electrode body; and An outer film for packaging the electrode body and the reinforcing member, The reinforcement component comprises: Main body; and a movable portion connected to the main body and joined to the exterior film, The movable portion is configured to be movable relative to the main body portion when the exterior film expands as the internal pressure of the electricity storage device increases.

2. The power storage device according to claim 1, wherein The reinforcing member includes at least a divided first member and a divided second member.

3. The power storage device according to claim 1 or 2, wherein The electrode body includes a current collector, The reinforcing member has a recessed portion for accommodating the current collector.

4. The power storage device according to claim 1 or 2, wherein The reinforcing member is plate-shaped and has a hole into which the electrode terminal is inserted. 5 . A reinforcing member used for the electricity storage device according to claim 1 .

6. The reinforcing member according to claim 5, wherein The reinforcing member is joined to the electrode terminal.

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