Power storage device

Abstract

To provide a power storage device which can be easily configured.SOLUTION: A power storage device includes an electrode body and an externally equipped body for sealing the electrode body. The externally equipped body includes: an external film for covering the electrode body to have an extension unit extending to the outside of the electrode body; and a sealed unit which is sealed in a manner that surfaces of the external film which face each other are joined to each other; an extension seal unit formed in the extension unit; and a back attachment seal unit extending in a direction which intersects with a direction in which the extension seal unit extends in plan view.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electricity storage device. [Background technology]

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

[0003] [Patent Document 1] JP2019-153504A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above electricity storage device, the opening of the exterior body is closed by the lid body, and therefore the device has many components.

[0005] An object of the present invention is to provide an electricity storage device that can be easily constructed. [Means for solving the problem]

[0006] The energy storage device according to a first aspect of the present invention comprises an electrode body and an exterior body that seals the electrode body, the exterior body including an exterior film that wraps the electrode body so as to have a protruding portion that protrudes outward beyond the electrode body, and a seal portion that is sealed by joining opposing surfaces of the exterior film, the seal portion including an protruding seal portion formed on the protruding portion and a back seal portion that extends in a direction intersecting the direction in which the protruding seal portion extends in a planar view.

[0007] An energy storage device according to a second aspect of the present invention is the energy storage device according to the first aspect, wherein the exterior film is wrapped around the electrode body so as to have the protruding portion, the back seal portion is formed by sealing a portion including a first edge and a portion including a second edge of the exterior film, and the protruding seal portion includes a portion where a portion including a third edge of the exterior film is sealed.

[0008] An electricity storage device according to a third aspect of the present invention is the electricity storage device according to the second aspect, wherein the protruding seal portion further includes a portion where a portion including a fourth edge of the exterior film is sealed.

[0009] An electricity storage device according to a fourth aspect of the present invention is an electricity storage device according to any one of the first to third aspects, wherein the protrusion has at least one side portion folded inward so that the outer surfaces of the exterior films face each other.

[0010] An electricity accumulation device according to a fifth aspect of the present invention is the electricity accumulation device according to the fourth aspect, wherein a base of the back seal portion is positioned outside the at least one side portion.

[0011] An energy storage device according to a sixth aspect of the present invention is an energy storage device according to any one of the third to fifth aspects, further comprising an electrode terminal electrically connected to the electrode body, the protrusion has a pair of side portions folded inward so that the outer surfaces of the exterior film face each other, the protrusion seal portion includes a pair of side seals which are portions where the pair of side portions are sealed, and a central seal portion located between the pair of side seal portions, and the central seal portion is sealed with the electrode terminal sandwiched between them.

[0012] An electricity accumulation device according to a seventh aspect of the present invention is the electricity accumulation device according to any one of the first to third aspects, wherein the width of the protruding portion in an expanded state is wider than the width of the electrode body.

[0013] An eighth aspect of the present invention is an energy storage device according to the seventh aspect, further comprising an electrode terminal electrically connected to the electrode body, wherein the protruding seal portion includes a pair of side seal portions located outside the widthwise ends of the electrode body when the protruding portion is expanded, and a central seal portion located between the pair of side seal portions, and the central seal portion is sealed with the electrode terminal sandwiched between them.

[0014] An electricity accumulation device according to a ninth aspect of the present invention is the electricity accumulation device according to the seventh or eighth aspect, wherein a base of the back seal portion includes a portion that overlaps with the protruding portion in an unfolded state in a plan view.

[0015] An electricity accumulation device according to a tenth aspect of the present invention is the electricity accumulation device according to any one of the seventh to ninth aspects, wherein at least a part of the protruding portion is folded so as to face a surface of the exterior body.

[0016] An energy storage device according to an eleventh aspect of the present invention is an energy storage device according to any one of the first to tenth aspects, wherein, in a plan view, the length of the portion of the protrusion excluding the protrusion seal portion in a direction along the back seal portion is equal to or greater than half the thickness of the electrode body.

[0017] An electricity accumulation device according to a twelfth aspect of the present invention is the electricity accumulation device according to any one of the first to eleventh aspects, wherein a base of the back seal portion is located on a boundary between surfaces of the electrode body.

[0018] An energy storage device according to a thirteenth aspect of the present invention comprises an electrode body, and an exterior body including an exterior film and sealing the electrode body, the exterior body including a sealing portion sealed by joining facing surfaces of the exterior film, and a through hole formed in at least one of the sealing portion and a portion outside the sealing portion with respect to the electrode body.

[0019] A fourteenth aspect of the present invention is an energy storage device according to the thirteenth aspect, wherein the outer casing has a protruding portion in which the outer casing film protrudes outward beyond the electrode body, the seal portion has a back seal portion in which a portion including a first edge and a portion including a second edge of the outer casing film are sealed, and a protruding seal portion formed on the protruding portion in which a portion including a third edge of the outer casing film is sealed, and the through hole is formed in the back seal portion.

[0020] An energy storage device according to a fifteenth aspect of the present invention is the energy storage device according to the fourteenth aspect, further comprising an electrode terminal electrically connected to the electrode body, and the protruding seal portion is sealed in a state in which the electrode terminal is sandwiched between the protruding seal portion.

[0021] An electricity storage device according to a sixteenth aspect of the present invention is an electricity storage device according to the fourteenth or fifteenth aspect, wherein the protrusion has at least one side portion folded inward so that the outer surfaces of the exterior films face each other.

[0022] An electricity accumulation device according to a seventeenth aspect of the present invention is the electricity accumulation device according to the fourteenth or fifteenth aspect, wherein the width of the protruding portion in an expanded state is wider than the width of the electrode body. Effect of the Invention

[0023] The electricity storage device according to the present invention can be easily configured. [Brief description of the drawings]

[0024] [Figure 1] FIG. 2 is a plan view of the electricity accumulation device according to the first embodiment. [Diagram 2] FIG. 2 is a side view of the electricity storage device of FIG. 1. [Diagram 3] FIG. 2 is a diagram showing the exterior film of the power storage device in FIG. 1 in an unfolded state. [Figure 4] 4 is a flowchart showing an example of a manufacturing process for the electricity storage device in FIG. [Diagram 5] FIG. 11 is a plan view of an electricity accumulation device according to a second embodiment. [Figure 6] FIG. 11 is a plan view of an electricity accumulation device according to a third embodiment. [Figure 7] 7 is a flowchart showing an example of a manufacturing process for the electricity storage device in FIG. 6. [Figure 8] FIG. 13 is a plan view of an electricity accumulation device according to a fourth embodiment. [Figure 9] FIG. 13 is a plan view of an electricity accumulation device according to a fifth embodiment. [Figure 10] FIG. 10 is a side view of the electricity storage device of FIG. [Figure 11] FIG. 10 is a front view of the electricity storage device in FIG. [Figure 12] 10 is a flowchart showing an example of a method for manufacturing the electricity accumulation device in FIG. [Figure 13] FIG. 13 is a cross-sectional view of an electricity accumulation device according to a modified example of the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, an electricity storage device according to one embodiment of the present invention will be described with reference to the drawings. In this specification, a numerical range indicated by "to" means "not less than" or "not more than." For example, the expression "2 to 15 mm" means 2 mm or more and 15 mm or less.

[0026] [1. First embodiment] <1-1. Configuration of the power storage device> Fig. 1 is a plan view that shows a schematic diagram of an electricity storage device 10 of a first embodiment. Fig. 2 is a side view of the electricity storage device 10 of Fig. 1. Fig. 3 is a diagram showing an exterior film 50 provided on the electricity storage device 10 of Fig. 1 in an unfolded state. In Figs. 1 and 2, the direction of arrows UD indicates the thickness direction of the electricity storage device 10, and the direction of arrows LR indicates the width direction of the electricity storage device 10. Furthermore, the direction of arrow FB indicates the depth direction of the electricity storage device 10. The directions indicated by the arrows UDLRFB are common to the subsequent figures.

[0027] The electricity storage device 10 includes an electrode body 20, an electrode terminal 30, and an exterior body 40. The electrode body 20 includes electrodes (positive and negative electrodes) constituting an electricity storage member such as a lithium ion battery, a capacitor, or an all-solid-state battery, as well as a separator. In this embodiment, the shape of the electrode body 20 is a substantially rectangular parallelepiped. Note that the term "substantially rectangular parallelepiped" includes not only a perfect rectangular parallelepiped, but also a solid body that can be regarded as a rectangular parallelepiped by modifying the shape of a portion of the outer surface, for example. The shape of the electrode body 20 may be, for example, a cylinder or a polygonal prism.

[0028] In this embodiment, the electricity storage device 10 includes two electrode terminals 30. The electrode terminals 30 are metal terminals used for inputting and outputting electric 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. The other end of the electrode terminal 30 protrudes outward from an edge of the exterior body 40.

[0029] The metal material constituting the electrode terminal 30 is, for example, aluminum, nickel, copper, etc. For example, when the electrode body 20 is a lithium ion battery, the electrode terminal 30 connected to the positive electrode is usually made of aluminum, etc., and the electrode terminal 30 connected to the negative electrode is usually made of copper, nickel, etc. The outermost layer of the electrode body 20 does not necessarily have to be an electrode, and may be, for example, a protective tape or a separator.

[0030] The exterior body 40 is composed of an exterior film 50, and seals the electrode body 20. In the electricity storage device 10, the exterior body 40 is formed by wrapping the exterior film 50 around the electrode body 20 and sealing the open portion.

[0031] For example, there is a method of forming a storage portion (recess) for storing the electrode body 20 in the exterior film 50 through cold forming. However, it is not necessarily easy to form a deep storage portion by such a method. If an attempt is made to form a deep storage portion (recess) by cold forming (for example, a forming depth of 15 mm), pinholes or cracks will occur in the exterior film 50, which is likely to cause a decrease in battery performance. On the other hand, the exterior body 40 seals the electrode body 20 by wrapping the exterior film 50 around the electrode body 20, so that the electrode body 20 can be easily sealed regardless of the thickness of the electrode body 20. In addition, in order to reduce the dead space between the electrode body 20 and the exterior film 50 to improve the volumetric energy density of the power storage device 10, it is preferable that the exterior film 50 is wrapped so as to contact the outer surface of the electrode body 20. In addition, in an all-solid-state battery, it is necessary to apply a high pressure uniformly from the outer surface of the battery to exhibit battery performance, so it is necessary to eliminate the space between the electrode body 20 and the exterior film 50, and therefore it is preferable that the exterior film 50 is wrapped so as to contact the outer surface of the electrode body 20.

[0032] The exterior film 50 is, for example, a laminate (laminate film) having a base layer, a barrier layer, and a heat-sealable resin layer in this order. Note that the exterior film 50 does not need to include all of these layers, and for example, may not include the barrier layer. That is, the exterior film 50 only needs to be made of a material that is flexible and easily bendable, and may be made of, for example, a resin film. Note that the exterior film 50 is preferably heat-sealable.

[0033] The substrate layer included in the exterior film 50 is a layer for imparting heat resistance to the exterior film 50 and suppressing the occurrence of pinholes that may occur during processing or distribution. The substrate layer is configured to include at least one layer of a stretched polyester resin layer and a stretched polyamide resin layer. For example, the substrate layer includes at least one layer of a stretched polyester resin layer and a stretched polyamide resin layer, so that the barrier layer can be protected during processing of the exterior film 50 and breakage of the exterior film 50 can be suppressed. In addition, from the viewpoint of increasing the tensile elongation of the exterior film 50, the stretched polyester resin layer is preferably a biaxially stretched polyester resin layer, and the stretched polyamide resin layer is preferably a biaxially stretched polyamide resin layer. Furthermore, in terms of excellent puncture strength or impact strength, the stretched polyester resin layer is more preferably a biaxially stretched polyethylene terephthalate (PET) film, and the stretched polyamide resin layer is more preferably a biaxially stretched nylon (ONy) film. The substrate layer may be configured to include both a stretched polyester resin layer and a stretched polyamide resin layer, and is preferably arranged in the order of a stretched polyester resin layer, an adhesive layer, and a stretched polyamide resin layer from the outside. From the viewpoint of film strength, the thickness of the substrate layer is preferably, for example, 5 to 300 μm, and more preferably 20 to 150 μm. As described above, when the substrate layer is a multilayer structure including a stretched polyester resin layer, an adhesive layer, and a stretched polyamide resin layer, the thickness of the substrate layer is preferably 25 to 35 μm, and more preferably 35 to 45 μm.

[0034] The barrier layer included in the exterior film 50 is made of, for example, aluminum foil from the viewpoints of processability such as moisture resistance and extensibility, and cost. The aluminum foil preferably contains iron from the viewpoints of packaging suitability and pinhole resistance when packaging the electrode body 20. The iron content in the aluminum foil is preferably 0.5 to 5.0 mass%, and more preferably 0.7 to 2.0 mass%. When the iron content is 0.5 mass% or more, the exterior film 50 can obtain packaging suitability, excellent pinhole resistance, and extensibility. When the iron content is 5.0 mass% or less, the exterior film 50 can obtain excellent flexibility. The barrier layer may include a metal foil, a vapor deposition film, and a resin layer having barrier properties. Examples of the metal foil include aluminum alloy, stainless steel, titanium steel, and steel plate.

[0035] From the viewpoints of barrier properties, pinhole resistance, and packaging suitability, the thickness of the barrier layer is, for example, preferably 15 to 100 μm, and more preferably 30 to 80 μm. The thickness of the barrier layer may be 30 to 50 μm, 50 to 70 μm, or 70 to 90 μm. When the thickness of the barrier layer is 15 μm or more, the exterior film 50 is less likely to break even when stress is applied during packaging processing. When the thickness of the barrier layer is 100 μm or less, the increase in mass of the exterior film 50 can be reduced, and a decrease in the weight energy density of the electricity storage device 10 can be suppressed.

[0036] In addition, when the barrier layer is an aluminum foil, it is preferable to provide a corrosion-resistant film at least on the surface opposite to the base layer in order to prevent dissolution and corrosion. The barrier layer may have a corrosion-resistant film on both sides. Here, the corrosion-resistant film refers to a thin film that is provided with corrosion resistance (e.g., acid resistance, alkali resistance, etc.) on the surface of the barrier layer by performing, for example, hydrothermal conversion treatment such as boehmite treatment, chemical conversion treatment, anodizing treatment, plating treatment such as nickel or chromium, or corrosion prevention treatment by applying a coating agent. Specifically, the corrosion-resistant film means a film that improves the acid resistance of the barrier layer (acid-resistant film), a film that improves the alkali resistance of the barrier layer (alkali-resistant film), etc. As a treatment for forming a corrosion-resistant film, one type may be performed, or two or more types may be combined. In addition, not only one layer but also multiple layers may be formed. Furthermore, among these treatments, hydrothermal conversion treatment and anodizing treatment are treatments in which the metal foil surface is dissolved by a treatment agent to form a metal compound with excellent corrosion resistance. These treatments may be included in the definition of chemical conversion treatment. In addition, when the barrier layer has a corrosion-resistant coating, the corrosion-resistant coating is also included in the barrier layer.

[0037] The corrosion-resistant coating prevents delamination between the barrier layer (e.g., aluminum alloy foil) and the base layer when the exterior film 50 is formed, prevents dissolution and corrosion of the barrier layer surface due to hydrogen fluoride produced by a reaction between an electrolyte and moisture, and in particular prevents dissolution and corrosion of aluminum oxide present on the barrier layer surface when the barrier layer is an aluminum alloy foil, and improves the adhesion (wettability) of the barrier layer surface, thereby preventing delamination between the base layer and barrier layer during heat sealing and between the base layer and barrier layer during forming.

[0038] The heat-sealable resin layer is bonded to the barrier layer, for example, via an adhesive layer. The heat-sealable resin layer included in the exterior film 50 is a layer that imparts heat-sealing sealability to the exterior film 50. Examples of the heat-sealable resin layer include resin films made of polyester resins such as polyethylene terephthalate resins and polybutylene terephthalate resins, polyolefin resins such as polyethylene resins and polypropylene resins, or acid-modified polyolefin resins obtained by graft-modifying these polyolefin resins with an acid such as maleic anhydride. The thickness of the heat-sealable resin layer is preferably, for example, 20 to 300 μm, more preferably 40 to 150 μm, from the viewpoints of sealability and strength.

[0039] The exterior film 50 preferably has one or more layers having a buffer function (hereinafter referred to as "buffer layer") outside the heat-sealable resin layer, more preferably outside the barrier layer. The buffer layer may be laminated on the outside of the base layer, or the base layer may also function as a buffer layer. When the exterior film 50 has multiple buffer layers, the multiple buffer layers may be adjacent to each other, or may be laminated via a base layer, a barrier layer, or the like.

[0040] The material constituting the buffer layer can be arbitrarily selected from materials having cushioning properties. The material having cushioning properties is, for example, rubber, nonwoven fabric, or foam sheet. The rubber is, for example, natural rubber, fluororubber, or silicone rubber. The rubber hardness is preferably about 20 to 90. The material constituting the nonwoven fabric is preferably a material having excellent heat resistance. When the buffer layer is made of nonwoven fabric, the lower limit of the thickness of the buffer layer is preferably 100 μm, more preferably 200 μm, and more preferably 1000 μm. When the buffer layer is made of nonwoven fabric, the upper limit of the thickness of the buffer layer is preferably 5000 μm, and more preferably 3000 μm. The thickness of the buffer layer is preferably in the range of 100 μm to 5000 μm, 100 μm to 3000 μm, 200 μm to 5000 μm, 200 μm to 3000 μm, 1000 μm to 5000 μm, or 1000 μm to 3000 μm. Among these, the thickness of the buffer layer is most preferably in the range of 1000 μm to 3000 μm.

[0041] When the buffer layer is made of rubber, the lower limit of the thickness of the buffer layer is preferably 0.5 mm. When the buffer layer is made of rubber, the upper limit of the thickness of the buffer layer is preferably 10 mm, more preferably 5 mm, and more preferably 2 mm. When the buffer layer is made of rubber, the preferred range of the thickness of the buffer layer is 0.5 mm to 10 mm, 0.5 mm to 5 mm, or 0.5 mm to 2 mm.

[0042] When the exterior film 50 has a buffer layer, the buffer layer functions as a cushion, thereby preventing the exterior film 50 from being damaged by impact when the electricity storage device 10 is dropped or by handling during production of the electricity storage device 10.

[0043] In this embodiment, the exterior film 50 is wrapped around the electrode body 20 so as to have an overhanging portion 70 that overhangs outward beyond the electrode body 20. With the exterior film 50 wrapped around the electrode body 20 so as to have the overhanging portion 70, the surfaces (thermally adhesive resin layers) of the exterior film 50 that face each other are heat sealed to form a sealed portion 60. In this embodiment, the overhanging portion 70 includes a first overhanging portion 71 and a second overhanging portion 72. The electrode body 20 is located between the first overhanging portion 71 and the second overhanging portion 72.

[0044] The first overhanging portion 71 faces the second overhanging portion 72 via the electrode body 20. The first overhanging portion 71 has a pair of side portions 71A, 71B in the short-side direction of the exterior body 40 in a plan view. The second overhanging portion 72 has a pair of side portions 72A, 72B in the short-side direction of the exterior body 40 in a plan view. In this embodiment, the side portions 71A, 71B, 72A, and 72B are folded inward so that the heat-sealable resin layers (inner surfaces) of the exterior film 50 face each other. In other words, the side portions 71A, 71B, 72A, and 72B are folded inward so that the base material layers (outer surfaces) of the exterior film 50 face each other. In this embodiment, the exterior body 40 is a so-called Gabeltop-type pouch.

[0045] The seal portion 60 includes a back seal portion 80 and a protruding seal portion 90. The back seal portion 80 is formed by heat sealing a portion including a first edge 51 and a portion including a second edge 52 of the exterior film 50 shown in FIG. 3. The back seal portion 80 extends in the longitudinal direction of the exterior body 40. The position at which the back seal portion 80 is formed in the exterior body 40 can be selected arbitrarily. In this embodiment, the base 80X of the back seal portion 80 is preferably located on the side 43X of the boundary between the first surface 41 and the second surface 42 of the exterior body 40. The first surface 41 has a larger area than the second surface 42. The base 80X of the back seal portion 80 may be located on any surface of the exterior body 40, and may be located outside the outer periphery of the electrode body 20 in a plan view. The base 80X of the back seal portion 80 may be located outside at least one of the side portions 71A, 71B, 72A, and 72B. When the base 80X of the back seal portion 80 is located outside at least one of the side portions 71A, 71B, 72A, and 72B, the back seal portion 80 and the protruding seal portion 90 are separated from each other, so that the back seal portion 80 and the protruding seal portion 90 can be easily formed. Furthermore, when another power storage device 10 is placed on the first surface 41, a gap is unlikely to be formed between the stacked power storage device 10, so that the loading efficiency is improved. In this embodiment, the back seal portion 80 protrudes outward from the electrode body 20 in a plan view. The back seal portion 80 may be folded toward the second surface 42 of the exterior body 40, for example.

[0046] In the electricity storage device 10 of this embodiment, the back seal portion 80 is not formed on the first surface 41 having a large area. The first surface 41 is flatter than when a sealing portion such as the back seal portion 80 is in contact with the first surface 41. Therefore, even if another electricity storage device 10 is placed on the first surface 41, the other electricity storage device 10 does not tilt. As a result, according to the electricity storage device 10, when a plurality of electricity storage devices 10 are stacked, unevenness in the distribution of pressure applied to the lower electricity storage device 10 can be suppressed. In other words, when a module is formed by stacking a plurality of electricity storage devices 10, the back seal portion 80 is not arranged on the surface (first surface 41) adjacent to the adjacent electricity storage device 10. In addition, such a configuration is preferable from the viewpoint that it is necessary to apply high pressure uniformly from the outer surface of the battery in an all-solid-state battery to exhibit battery performance.

[0047] The overhanging seal portion 90 includes a first overhanging seal portion 91 and a second overhanging seal portion 92. The first overhanging seal portion 91 is formed in the first overhanging portion 71. The first overhanging seal portion 91 extends in the short direction of the exterior body 40. The first overhanging seal portion 91 is formed by heat-sealing a portion of the exterior film 50 including the third edge 53. The first overhanging seal portion 91 includes a pair of side seal portions 91A and a central seal portion 91B. The pair of side seal portions 91A are portions where the heat-fusible resin layers of the pair of folded side portions 71A and 71B are heat-sealed to each other. The central seal portion 91B is a portion located between the pair of side seal portions 91A. The central seal portion 91B is sealed with the electrode terminal 30 sandwiched therebetween.

[0048] The second overhanging seal portion 92 is formed in the second overhanging portion 72. The second overhanging seal portion 92 extends in the short direction of the exterior body 40. The second overhanging seal portion 92 is formed by heat-sealing a portion of the exterior film 50 including the fourth edge 54 (see FIG. 3). The second overhanging seal portion 92 includes a pair of side seal portions 92A and a central seal portion 92B. The pair of side seal portions 92A are portions where the heat-fusible resin layers of the pair of folded side portions 72A, 72B are heat-sealed to each other. The central seal portion 92B is a portion located between the pair of side seal portions 92A. The central seal portion 92B is sealed with the two electrode terminals 30 sandwiched therebetween.

[0049] The relationship between the seal width HA of the back seal portion 80 and the seal width HB of the protruding seal portion 90 can be selected arbitrarily. In this embodiment, the seal width HA of the back seal portion 80 is wider than the seal width HB of the protruding seal portion 90.

[0050] In a plan view, the length LA of the portion of the overhanging portion 70 excluding the overhanging seal portion 90 in the direction along the back seal portion 80 can be selected arbitrarily. From the viewpoint of suppressing interference between the seal bar and the electrode body 20 when forming the overhanging seal portion 90 in the manufacturing process of the electricity storage device 10, it is preferable that the length LA be equal to or greater than half the thickness LB of the electrode body 20 (see FIG. 2).

[0051] <1-2. Method for manufacturing electricity storage device> 4 is a flowchart showing an example of a method for manufacturing the power storage device 10. The method for manufacturing the power storage device 10 includes, for example, a first step, a second step, a third step, a fourth step, and a fifth step. The first step to the fifth step are performed by, for example, a manufacturing apparatus for the power storage device 10.

[0052] In the first process of step S11, the manufacturing equipment wraps the exterior film 50 around the electrode body 20 so that a protruding portion 70 is formed in the electrode body 20.

[0053] The second step of step S12 is performed after the first step. In the second step, the manufacturing device heat-seals the heat-sealable resin layer of the portion including the first edge 51 of the exterior film 50 and the heat-sealable resin layer of the portion including the second edge 52 to form a back-attached seal portion (hereinafter referred to as a "temporary back-attached seal portion") having a part that is not sealed. The unsealed portion can be formed, for example, by using a seal bar having a shape that does not contact the exterior film 50. In another example, the unsealed portion can be formed by interposing a fluororesin film or the like between the mutually facing surfaces (heat-sealable resin layers) of the exterior film 50. By forming the temporary back-attached seal portion before the first protruding seal portion 91 and the second protruding seal portion 92, the electrode body 20 can be held by the exterior film 50, so that the position of the electrode body 20 relative to the exterior film 50 is unlikely to shift. Therefore, when the first protruding seal portion 91 and the second protruding seal portion 92 are formed, the occurrence of wrinkles is suppressed.

[0054] The third step of step S13 is carried out after the second step. In the third step, the manufacturing device folds the side portions 71A, 71B of the first protruding portion 71 inward and heat-seals the heat-fusible resin layers of the portion including the third edge 53 of the exterior film 50 to form the first protruding seal portion 91. When forming the first protruding seal portion 91 in the third step, the manufacturing device also heat-seals the end of the back seal portion 80 on the first protruding portion 71 side again. Therefore, the end of the back seal portion 80 on the first protruding portion 71 side is double-sealed.

[0055] The fourth step of step S14 is performed after the third step. In the fourth step, the manufacturing device folds the side portions 72A and 72B of the second overhang portion 72 inward and heat-seals the heat-fusible resin layers of the portion including the fourth edge 54 of the exterior film 50 to form the second overhang seal portion 92. When forming the second overhang seal portion 92 in the fourth step, the manufacturing device also heat-seals the end of the back seal portion 80 on the second overhang portion 72 side again. Therefore, the end of the back seal portion 80 on the second overhang portion 72 side is double-sealed. The order of the fourth step and the third step may be reversed.

[0056] The fifth step of step S15 is performed after the third step or the fourth step. In the fifth step, the manufacturing equipment injects an electrolyte solution from an unsealed portion of the temporary back seal portion, evacuates the exterior film 50, and then heat-seals the unsealed portion to form the back seal portion 80. Note that, when the power storage device 10 is an all-solid-state battery, the step of injecting the electrolyte solution in the fifth step is omitted.

[0057] <1-3. Actions and Effects of Electricity Storage Devices> The electricity storage device 10 includes an electrode body 20 and an exterior body 40 that seals the electrode body 20. The exterior body 40 includes an exterior film 50 that wraps the electrode body 20 so as to have a protruding portion 70 that protrudes outward beyond the electrode body 20, and a seal portion 60 that is sealed by joining opposing surfaces of the exterior film 50. The seal portion 60 includes a protruding seal portion 90 formed on the protruding portion 70, and a back seal portion 80 that extends in a direction intersecting the direction in which the protruding seal portion 90 extends in a plan view. According to the electricity storage device 10, the electrode body 20 is sealed without using a lid or the like, and therefore the configuration can be simplified.

[0058] [2. Second embodiment] The power storage device 200 of the second embodiment differs from the first embodiment in that it includes a protruding portion 270 and a protruding seal portion 290, but other configurations are similar to those of the first embodiment. The following describes the power storage device 200 of the second embodiment, focusing on the differences from the first embodiment.

[0059] <2-1. Configuration of the power storage device> FIG. 5 is a plan view that illustrates a schematic diagram of an electricity storage device 200 according to a second embodiment. In this embodiment, the overhanging portion 270 includes a first overhanging portion 271 and a second overhanging portion 272 that face each other via the electrode body 20. The first overhanging portion 271 has a pair of side portions 271A and 271B in the short-side direction of the exterior body 40 in a plan view. The second overhanging portion 272 has a pair of side portions 272A and 272B in the short-side direction of the exterior body 40 in a plan view. In this embodiment, unlike the first embodiment, the side portions 271A, 271B, 272A, and 272B are not folded inward so that the inner surfaces of the exterior film 50 face each other, in other words, the outer surfaces of the exterior film 50 face each other. The width XA of the overhanging portion 270 in the unfolded state is wider than the width XB of the electrode body 20. In this embodiment, the exterior body 40 is a so-called brick-shaped pouch. In this embodiment, the base 80X of the back sticker portion 80 overlaps with the first protruding portion 271 and the second protruding portion 272 in a plan view.

[0060] The overhang seal portion 290 includes a first overhang seal portion 291 and a second overhang seal portion 292. The first overhang seal portion 291 is formed in the first overhang portion 271. The first overhang seal portion 291 extends in the short direction of the exterior body 40. The first overhang seal portion 291 is formed by heat-sealing a portion of the exterior film 50 including the third edge 53. The first overhang seal portion 291 includes a pair of side seal portions 291A and a central seal portion 291B. The pair of side seal portions 291A are portions in which the heat-fusible resin layers of the exterior film 50 located outside the ends of the electrode body 20 in the width direction are heat-sealed to each other. The central seal portion 291B is a portion located between the pair of side seal portions 291A. The central seal portion 291B is sealed with the electrode terminal 30 sandwiched therebetween. From the viewpoint of configuring the power storage device 200 compactly, in the first overhanging portion 271, the central seal portion 291B may be folded so as to face the third surface 43 of the exterior body 40, and may be joined to the third surface 43 by adhesive or the like. In addition, in a state in which the central seal portion 291B is folded so as to face the third surface 43 of the exterior body 40, the pair of side seal portions 291A may be folded so as to face the pair of second surfaces 42 or third surfaces 43 of the exterior body 40, and may be joined to the second surface 42 or third surface 43 by adhesive or the like. Note that, when at least one of the pair of side seal portions 291A is folded so as to face the second surface 42 or third surface 43 of the exterior body 40, the width XA of the overhanging portion 270 may be narrower than the width XB of the electrode body 20. The width XA of the overhanging portion 270 is the width when the pair of side seal portions 291A is in an expanded state.

[0061] The second overhang seal portion 292 is formed in the second overhang portion 272. The second overhang seal portion 292 extends in the short direction of the exterior body 40. The second overhang seal portion 292 is formed by heat-sealing a portion of the exterior film 50 including the fourth edge 54. The second overhang seal portion 292 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 exterior film 50 in which the heat-fusible resin layers of portions located outside the ends of the electrode body 20 in the width direction 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 in which the two electrode terminals 30 are sandwiched between them. From the viewpoint of configuring the power storage device 200 compactly, in the second overhanging portion 272, the central seal portion 292B may be folded so as to face the fourth surface 44 of the exterior body 40, and may be joined to the fourth surface 44 by adhesive or the like. In addition, in a state in which the central seal portion 292B is folded so as to face the fourth surface 44 of the exterior body 40, the pair of side seal portions 292A may be folded so as to face the pair of second surfaces 42 or fourth surfaces 44 of the exterior body 40, and may be joined to the second surface 42 or fourth surface 44 by adhesive or the like. Note that, when at least one of the pair of side seal portions 292A is folded so as to face the second surface 42 or fourth surface 44 of the exterior body 40, the width XA of the overhanging portion 270 may be narrower than the width XB of the electrode body 20. The width XA of the overhanging portion 270 is the width when the pair of side seal portions 292A is in an expanded state. According to the power storage device 200 of the present embodiment, the same effects as those of the power storage device 10 of the first embodiment can be obtained.

[0062] <2-2. Manufacturing method of electricity storage device> The electricity storage device 200 of this embodiment can be manufactured, for example, by a method similar to the manufacturing method of the electricity storage device 10 of the first embodiment. The electricity storage device 200 can be manufactured by omitting the folding inward of the side portions 271A, 271B of the first protrusion 271 in the third step of the manufacturing method of the electricity storage device 10 of the first embodiment, and omitting the folding inward of the side portions 272A, 272B of the second protrusion 272 in the fourth step.

[0063] [3. Third embodiment] The power storage device 300 of the third embodiment differs from the first embodiment in that it includes a through hole 60A, but other configurations are similar to those of the first embodiment. The following describes the power storage device 300 of the third embodiment, focusing on the differences from the first embodiment.

[0064] Japanese Patent Publication No. 4509242 discloses an example of an electricity storage device, which includes an electrode assembly and an exterior film that seals the electrode assembly.

[0065] In recent years, there has been a demand for higher capacity electricity storage devices. This has resulted in an increase in the weight of the electrode body, making it difficult to fix the electricity storage device at a desired position when transporting the electricity storage device and when placing the electricity storage device at an installation location. The electricity storage device 300 of the third embodiment aims to provide an electricity storage device that can be easily fixed at a desired position.

[0066] <3-1. Configuration of the power storage device> In this embodiment, a through hole 60A penetrating the exterior body 40 is formed in the seal portion 60 so that the power storage device 300 can be easily fixed at a desired position. For example, a jig for fixing the power storage device 300 is attached to the through hole 60A. The jig is, for example, a rod inserted into the through hole 60A, or a pin inserted into the through hole 60A. When the jig is a rod, the power storage device 300 may be fixed by fixing the rod and the back-attached seal portion 80 with, for example, a clip while the jig is inserted into the through hole 60A. When the jig is a pin, the power storage device 300 may be fixed by inserting the pin into the through hole 60A and hammering the pin into a plate.

[0067] The position where the through hole 60A is formed in the seal portion 60 can be selected arbitrarily. The through hole 60A is preferably formed in the back seal portion 80 having a wide seal width. Since the through hole 60A is formed at a position away from the electrode terminal 30, the through hole 60A and the electrode terminal 30 are unlikely to interfere with each other. Since the through hole 60A is formed in the back seal portion 80 having a wide seal width of the seal portion 60, the area of ​​the through hole 60A is large. Since the distance between the through hole 60A and the outer edge of the back seal portion 80 can be sufficiently secured, the barrier property of the exterior body 40 is unlikely to decrease. In this embodiment, as shown in FIG. 1, the through hole 60A is formed in the back seal portion 80 near the first protruding seal portion 91.

[0068] The shape of the through hole 60A can be selected arbitrarily. In this embodiment, the shape of the through hole 60A is a circle. The shape of the through hole 60A may be an ellipse, a triangle, a rectangle, or a polygon having pentagons or more sides.

[0069] The number of through holes 60A formed in the seal portion 60 can be selected arbitrarily. In this embodiment, the number of through holes 60A formed in the seal portion 60 is one. The number of through holes 60A formed in the seal portion 60 may be two or more.

[0070] <3-2. Manufacturing method of electricity storage device> Fig. 7 is a flowchart showing an example of a method for manufacturing the power storage device 300. The method for manufacturing the power storage device 300 includes, for example, a sixth step in addition to the first step to the fifth step (see Fig. 4) of the first embodiment. The first step to the sixth step are performed, for example, by a manufacturing apparatus for the power storage device 300. Note that the first step to the fifth step are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0071] The sixth step of step S16 is performed after the fifth step. In the sixth step, the manufacturing apparatus forms a through hole 60A in the back seal portion 80. Since the through hole 60A is formed in the back seal portion 80, for example, by attaching a jig to the through hole 60A, the plurality of electricity storage devices 10 can be easily transported. In addition, the plurality of electricity storage devices 10 can be easily aligned. Note that the sixth step may be performed after the second step and before the third step or the fourth step. In other words, the through hole 60A may be formed in a sealed portion of the temporary back seal portion.

[0072] <3-3. Actions and Effects of Electricity Storage Devices> According to the electricity storage device 300, a through hole 60A is formed in the seal portion 60. Therefore, even if the weight of the electrode body 20 is heavy, the electricity storage device 10 can be easily fixed in a desired position by attaching a jig to the through hole 60A.

[0073] [4. Fourth embodiment] The power storage device 400 of the fourth embodiment differs from the second embodiment in that it includes a through hole 60A, but other configurations are similar to those of the second embodiment. The following describes the power storage device 400 of the fourth embodiment, focusing on the differences from the second embodiment.

[0074] <4-1. Configuration of the power storage device> In this embodiment, the through hole 60A is formed at approximately the center in the longitudinal direction of the back seal portion 80. Since the through hole 60A is formed in a portion where the back seal portion 80 and the protruding portion 70 do not overlap in a plan view, a tool can be easily inserted into the through hole 60A. According to the electricity storage device 400 of this embodiment, the same effects as those of the electricity storage device 300 of the third embodiment can be obtained.

[0075] <4-2. Manufacturing method of electricity storage device> The power storage device 400 of this embodiment can be manufactured, for example, by a method similar to the manufacturing method of the power storage device 300 of the third embodiment. The power storage device 400 can be manufactured by omitting inward folding of the side portions 271A, 271B of the first protrusion 271 in the third step of the manufacturing method of the power storage device 300 of the third embodiment, and omitting inward folding of the side portions 272A, 272B of the second protrusion 272 in the fourth step.

[0076] [5. Fifth Embodiment] The power storage device 500 of the fifth embodiment differs from the third embodiment in that it includes an exterior body 340, but other configurations are similar to those of the third embodiment. The following describes the power storage device 500 of the fifth embodiment, focusing on the differences from the third embodiment.

[0077] <5-1. Configuration of the power storage device> Fig. 9 is a plan view that typically illustrates an electricity storage device 500 of a fifth embodiment. Fig. 10 is a side view of the electricity storage device 500 of Fig. 9. Fig. 11 is a front view of the electricity storage device 300 of Fig. 9.

[0078] The electricity storage device 500 includes an exterior body 340. The exterior body 340 is formed by fitting a lid body 600 into each of the openings at both ends of an exterior film 50 wrapped around the electrode assembly 20. With the lid body 600 fitted in, the exterior film 50 and the lid body 600 are heat sealed together.

[0079] The lid body 600 is a bottomed tray-like member having a rectangular shape in a plan view, and is formed by, for example, cold forming the exterior film 50. The lid body 600 does not necessarily have to be made of the exterior film 50, and may be a metal molded product or a resin molded product. In the power storage device 500, the lid body 600 is arranged so that the bottom side of the lid body 600 is located inside the exterior body 340. In the power storage device 500, the bottom side of the lid body 600 does not necessarily have to be located inside the exterior body 340. In the power storage device 500, the bottom side of the lid body 600 may be located outside the exterior body 340.

[0080] When the electrode body 20 is stored, the electrode terminal 30 protrudes to the outside of the exterior body 340 through a through hole formed in the lid body 600. A small gap between the through hole of the lid body 600 and the electrode terminal 30 is filled with, for example, resin. In the electricity storage device 500, the position from which the electrode terminal 30 protrudes to the outside can be selected arbitrarily. For example, the electrode terminal 30 may protrude to the outside from a hole formed in any one of the six faces of the exterior body 340. In this case, a small gap between the exterior body 340 and the electrode terminal 30 is filled with, for example, resin. In the electricity storage device 500, the lid body 600 and the electrode terminal 30 are provided as separate bodies, but the lid body 600 and the electrode terminal 30 may be formed integrally.

[0081] In this embodiment, the back seal portion 80 is folded toward the second surface 42 of the exterior body 40. The back seal portion 80 and the second surface 42 are not joined. The through hole 60A is formed in the back seal portion 80 near one of the lid bodies 600. According to the electricity storage device 500 of this embodiment, the same effects as those of the electricity storage device 300 of the third embodiment can be obtained.

[0082] <5-2. Manufacturing method of electricity storage device> 12 is a flowchart showing an example of a method for manufacturing the power storage device 500. The method for manufacturing the power storage device 500 includes, for example, a first step, a second step, a third step, and a fourth step. The first step to the fourth step are performed by, for example, a manufacturing apparatus for the power storage device 500.

[0083] In the first step of step S21, the manufacturing equipment places the lid body 600 with the electrode terminals 30 attached to both ends of the electrode body 20. By completing the first step, the electrode terminals 30 and the electrodes of the electrode body 20 are electrically connected to each other.

[0084] The second process of step S22 is carried out after the first process. In the second process, the manufacturing device wraps the exterior film 50 around the electrode body 20 and the lid body 600.

[0085] The third step of step S23 is carried out after the second step. In the third step, the manufacturing device heat-seals the heat-fusible resin layer of the portion including the first edge 51 of the exterior film 50 and the heat-fusible resin layer of the portion including the second edge 52 to form a temporary back seal portion.

[0086] The fourth step of step S24 is carried out after the third step. The manufacturing device seals the electrode body 20 by heat sealing the exterior film 50 and the lid body 600 together.

[0087] The fifth step of step S25 is performed after the fourth step. In the fifth step, the manufacturing apparatus injects an electrolyte solution from an unsealed portion of the temporary back seal portion, evacuates the exterior film 50, and then heat-seals the unsealed portion to form the back seal portion 80. When the power storage device 500 is an all-solid-state battery, the step of injecting the electrolyte solution in the fifth step is omitted.

[0088] The sixth step of step S26 is performed after the fifth step. In the sixth step, the manufacturing device forms a through hole 60A in the back seal portion 80. The sixth step may be performed after the third step and before the fourth step. In other words, the through hole 60A may be formed in the sealed portion of the temporary back seal portion.

[0089] <6. Variations> The above-mentioned embodiments are examples of forms that the power storage device according to the present invention can take, and are not intended to limit the forms. The power storage device according to the present invention can take forms different from those exemplified in the embodiments. One example is a form in which a part of the configuration of each embodiment is replaced, changed, or omitted, or a form in which a new configuration is added to each embodiment. Below, some examples of modified versions of each embodiment are shown. The following modified versions can be combined with each other as long as there is no technical contradiction.

[0090] <6-1> In the first embodiment, the shape of the exterior body 40 can be changed arbitrarily. In the exterior body 40, one to three of the side portions 71A, 71B, 72A, and 72B of the overhanging portion 70 do not need to be folded. For example, the side portions 71A and 71B of the first overhanging portion 71 or the side portions 72A and 72B of the second overhanging portion 72 do not need to be folded inward. In this modification, the exterior body 40 is a pouch having a shape that is a mixture of a Gabeltop type and a brick type.

[0091] <6-2> In the first and second embodiments, the shape of the exterior body 40 may be, for example, a bag shape such as a three-sided sealed type, a four-sided sealed type, a pillow type, or a gusset type.

[0092] <6-3> In the first and second embodiments, the form of sealing the portion including the fourth edge 54 of the exterior film 50 can be changed as desired. For example, in the exterior body 40, the fourth edge 54 of the exterior film 50 may be sealed with a lid body arranged on the side of the electrode body 20, thereby sealing the electrode body 20.

[0093] <6-4> In the first embodiment, the two electrode terminals 30 may protrude, for example, from the first protruding portion 71 or the second protruding portion 72 of the exterior body 40. Similarly, in the second embodiment, the two electrode terminals 30 may protrude from the first protruding portion 271 or the second protruding portion 272.

[0094] <6-5> In the third and fourth embodiments, the position where the through hole 60A is formed can be selected arbitrarily. For example, in the third embodiment, the through hole 60A may be formed in at least one of the first protruding seal portion 91 and the second protruding seal portion 92. For example, in the fourth embodiment, the through hole 60A may be formed in at least one of the first protruding seal portion 291 and the second protruding seal portion 292.

[0095] <6-6> In the third embodiment, the shape of the exterior body 40 can be changed arbitrarily. In the exterior body 40, one to three of the side portions 71A, 71B, 72A, and 72B of the overhanging portion 70 do not need to be folded. For example, the side portions 71A and 71B of the first overhanging portion 71 or the side portions 72A and 72B of the second overhanging portion 72 do not need to be folded inward. In this modification, the exterior body 40 is a pouch having a shape that is a mixture of a Gabeltop type and a brick type.

[0096] In another example, as shown in FIG. 13, the exterior body 40 may have an extension portion 100 that is connected to the back seal portion 80 and is located outside the back seal portion 80 with respect to the electrode body 20. The extension portion 100 includes a folded portion 110 in which the exterior film 50 is folded back, and an unsealed portion 120 that is located between the folded portion 110 and the back seal portion 80. In the folded portion 110, the heat-sealable resin layers of the folded exterior film 50 that face each other are heat-sealed. In the unsealed portion 120, the exterior film 50 is not sealed. In this modification, a through hole 60A may be formed in the folded portion 110, and a through hole 60B may be formed in the unsealed portion 120. That is, in this modification, at least one of the through hole 60A and the through hole 60B may be formed.

[0097] In another example, the shape of the exterior body 40 may be a bag (pouch) shape. The bag shape may be, for example, a three-sided sealed type, a four-sided sealed type, a pillow type, a gusset type, or the like.

[0098] <6-7> In the third embodiment, the two electrode terminals 30 may protrude, for example, from the first protruding portion 71 or the second protruding portion 72 of the exterior body 40. Similarly, in the fourth embodiment, the two electrode terminals 30 may protrude from the first protruding portion 271 or the second protruding portion 272.

[0099] <6-8> In the third embodiment, the electricity storage device 10 may be manufactured using an exterior film 50 in which the through holes 60A are formed in advance. In this modification, a pair of through holes 60A are formed in advance in the exterior film 50 at a position where the back seal portion 80 is to be formed. The manufacturing apparatus wraps the exterior film 50 around the electrode body 20 so that the positions of the pair of through holes 60A coincide with each other, and forms the back seal portion 80 in a state where a predetermined tension is applied to the exterior film 50. The electricity storage device 400 of the fourth embodiment and the electricity storage device 500 of the fifth embodiment can also be manufactured by a similar method.

[0100] <6-9> In the third and fourth embodiments, the form of sealing the portion including the fourth edge 54 of the exterior film 50 can be changed as desired. For example, in the exterior body 40, the fourth edge 54 of the exterior film 50 may be sealed with a lid body arranged on the side of the electrode body 20, thereby sealing the electrode body 20. [Explanation of symbols]

[0101] 10, 200, 300: Energy storage device 20: Electrode body 30: Electrode terminal 40, 340: Exterior body 50: Exterior film 51: First Edge 52: Second Edge 53: The third edge 54: The Fourth Edge 60: Seal part 60A, 60B: Through hole 70, 270: Overhang 71A, 271A: Side 71B, 271B: Side 72A, 272A: Side 72B, 272B: Side 80: Back sticker section 90, 290: Protruding seal part

Claims

1. An electrode body; an exterior body that seals the electrode body, the exterior body is an exterior film that wraps the electrode body so as to have a protruding portion that protrudes outward beyond the electrode body; a seal portion formed by joining the opposing surfaces of the exterior film together, The sealing portion is a protruding seal portion formed on the protruding portion; a back seal portion extending in a direction intersecting the direction in which the protruding seal portion extends in a plan view; the exterior film is wrapped around the electrode body so as to have the protruding portion, The spine seal portion seals a portion including a first edge and a portion including a second edge of the exterior film, the protruding seal portion includes a portion where a portion including a third edge of the exterior film is sealed, The protruding portion has a first side portion folded inward on the side of the spine seal portion so that the outer surfaces of the exterior films face each other, and a second side portion folded inward on the side opposite to the spine seal portion so that the outer surfaces of the exterior films face each other, a base of the spine seal portion is located outside the first side portion; The tip of the back seal portion extends outward in the extending direction of the protruding seal portion in a plan view. Energy storage device.

2. The protruding seal portion further includes a portion where a portion including a fourth edge of the exterior film is sealed. The electricity storage device according to claim 1 .

3. the electrode assembly further includes an electrode terminal electrically connected to the electrode body, the protruding seal portion including a pair of side seal portions where the first side portion and the second side portion are sealed, and a central seal portion located between the pair of side seal portions; The central seal portion is sealed with the electrode terminal sandwiched therebetween. The electricity storage device according to claim 1 or 2.

4. In a plan view, the length of the portion of the protruding portion excluding the protruding seal portion in a direction along the back seal portion is equal to or greater than half the thickness of the electrode body. The electricity storage device according to claim 1 or 2.

5. The base of the back seal portion is located on the boundary between the surfaces of the electrode body. The electricity storage device according to claim 1 or 2.

6. A through hole is provided in the back seal portion. The electricity storage device according to claim 1 or 2.

Images