Electric storage device and method for manufacturing the same

Abstract

A power storage device (1) includes: a housing main body (210) made of metal and having an opening in at least one direction; a power storage module (100) disposed within the housing main body; a blocking plate (220) made of metal and welded to the housing main body so as to block the opening of the housing main body; an insulating sheet (300) covering the inner surface of the housing main body and the inner surface of the blocking plate; and a covering portion (400) made of an insulating material and covering the boundary portion (215) between the inner surface of the housing main body and the inner surface of the blocking plate.

Description

Technical Field

[0001] The present disclosure relates to an electricity storage device and a method for manufacturing the same. Background Art

[0002] For example, Japanese Patent Application Laid-Open No. 2003-187755 discloses a secondary battery including a case and a plurality of electrodes housed in the case. The case has a box-shaped portion with an upper opening and a lid portion that closes the opening of the box-shaped portion. Insulating films are provided on the inner surface of the box-shaped portion and the inner surface of the lid portion. Summary of the Invention

[0003] In the secondary battery described in Japanese Patent Application Laid-Open No. 2003-187755, the lid portion is welded to the box-shaped portion, and thus, the insulating film melts at the boundary portion between the box-shaped portion and the lid portion. In this case, the insulation becomes insufficient.

[0004] An object of the present disclosure is to provide an electricity storage device capable of ensuring insulation and a method for manufacturing the same.

[0005] An electricity storage device according to one aspect of the present disclosure includes a housing main body, an electricity storage module, a blocking plate, an insulating sheet, and a covering portion. The housing main body is made of metal and has an opening in at least one direction. The electricity storage module is disposed in the housing main body. The blocking plate is made of metal and is welded to the housing main body so as to block the opening of the housing main body. The insulating sheet covers the inner surface of the housing main body and the inner surface of the blocking plate. The covering portion is made of an insulating material and covers the boundary portion between the inner surface of the housing main body and the inner surface of the blocking plate.

[0006] In addition, a method for manufacturing an electricity storage device according to one aspect of the present disclosure includes a preparation step, a disposition step, a welding step, and an injection step. In the preparation step, a housing main body and a blocking plate are prepared. The housing main body is made of metal, has an insulating sheet on its inner surface, and has an opening in at least one direction. The blocking plate is made of metal, has an insulating sheet on its inner surface, and is shaped to block the opening of the housing main body. In the disposition step, the electricity storage module is disposed in the housing main body. In the welding step, the blocking plate is welded to the housing main body so that the opening of the housing main body is blocked by the blocking plate. In the injection step, an insulating material having insulating properties is injected into the housing main body from the outside of the housing main body so as to form a covering portion that covers the boundary portion between the inner surface of the housing main body and the inner surface of the blocking plate.

[0007] The above and other objects, features, aspects, and advantages of the present invention will become apparent from the following detailed description of the present invention when read in conjunction with the accompanying drawings. Brief Description of the Drawings

[0008] Figure 1 This is a cross-sectional view schematically showing the structure of an energy storage device according to an embodiment of the present disclosure.

[0009] Figure 2 This is a cross-sectional view schematically showing the state after the welding process. Detailed Embodiment

[0010] Embodiments of the present disclosure will be described with reference to the accompanying drawings. In the accompanying drawings referred to below, the same or corresponding components are given the same reference numerals.

[0011] Figure 1 This is a perspective view schematically showing the structure of an energy storage device according to an embodiment of the present disclosure. The energy storage device 1 is mounted on a vehicle, for example.

[0012] As Figure 1 shown, the energy storage device 1 includes: an energy storage module 100, a housing 200, an insulating sheet 300, and a covering portion 400. A cooling device 2 can be provided in contact with the energy storage device 1.

[0013] The energy storage module 100 has at least one energy storage unit 101. In the present embodiment, the energy storage module 100 has a plurality of energy storage units 101. The plurality of energy storage units 101 are stacked in one direction. Furthermore, Figure 1 although 3 energy storage units 101 are shown, the number of energy storage units 101 is not particularly limited. As the energy storage unit 101, for example, a lithium-ion battery can be cited.

[0014] The energy storage unit 101 is a so-called laminated type unit. That is, the energy storage unit 101 has a plurality of electrode bodies 110, current collector plates 120, a laminated film 130, an adhesive member 140, and an electrolytic solution (not shown). Furthermore, the energy storage unit 101 can also be composed of an all-solid-state battery having a solid electrolyte instead of a separator and an electrolytic solution.

[0015] The plurality of electrode bodies 110 are stacked in one direction. The end portions of each electrode body 110 are electrically connected to the current collector plate 120.

[0016] The laminated film 130 covers a part of the plurality of electrode bodies 110 and the current collector plates 120. The end portions of the current collector plates 120 protrude from the laminated film 130. The end portions of each current collector plate 120 are connected by a bus bar 102 so that the plurality of energy storage units 101 are electrically connected in series. The laminated film 130 is connected to the current collector plate 120 via the adhesive member 140. An electrolytic solution is filled in the laminated film 130.

[0017] The housing 200 houses the energy storage module 100. The housing 200 is made of metal (such as aluminum). The housing 200 has a housing main body 210 and a blocking plate 220.

[0018] The housing main body 210 is open in at least one direction. In the present embodiment, the housing main body 210 is formed in a rectangular tube shape having a central axis extending in a direction orthogonal to the stacking direction of each power storage unit 101. An injection port h (see Figure 2 ) is provided on the housing main body 210.

[0019] The blocking plate 220 is welded to the housing main body 210 so as to block the opening of the housing main body 210. The blocking plate 220 is formed in a flat plate shape.

[0020] The cooling device 2 is arranged to be in contact with the blocking plate 220. In other words, the cooling device 2 is arranged to be in contact with the housing 200 in a direction orthogonal to the stacking direction of each power storage unit 101.

[0021] The insulating sheet 300 covers the inner surfaces of the housing main body 210 and the blocking plate 220. The insulating sheet 300 may also cover the outer surface of the housing main body 210.

[0022] The covering portion 400 is made of an insulating material having insulation properties. The covering portion 400 is preferably made of a material having heat conductivity. The covering portion 400 covers the boundary portion 215 between the inner surface of the housing main body 210 and the inner surface of the blocking plate 220. The covering portion 400 is formed by injecting the insulating material (in this embodiment, a potting material) into the housing 200 through the injection port h of the housing 200. The covering portion 400 preferably covers, together with the bonding member 140, the entire area of the portion of the current collector plate 120 protruding from the laminated film 130 and the entire area of the bus bar 102. In this way, the relative displacement of the power storage module 100 with respect to the housing 200 can be suppressed. The covering portion 400 covers the insulating sheet 300 provided on the inner surface of the blocking plate 220.

[0023] As Figure 1 shown, the power storage device 1 may further include a restricting unit 500. The restricting unit 500 is disposed between the power storage module 100 and the housing main body 210. Furthermore, the restricting unit 500 may also be disposed between a pair of adjacent power storage units 101.

[0024] The restricting unit 500 restricts the relative displacement of the power storage module 100 with respect to the housing 200 in the stacking direction of each power storage unit 101. The restricting unit 500 is made of a material having dilatancy, for example. That is, when each power storage unit 101 expands or the like, and each power storage unit 101 relatively displaces with respect to the housing 200 at a small speed in the stacking direction, the restricting unit 500 absorbs the expansion of each power storage unit 101 by elastic deformation. On the other hand, when the power storage device 1 vibrates or the like, and each power storage unit 101 relatively displaces with respect to the housing 200 at a relatively large speed in the stacking direction, the restricting unit 500 restricts the relative displacement of each power storage unit 101 with respect to the housing 200 by exhibiting a relatively large elastic modulus. Thereby, the resonance of the power storage module 100 when the power storage device 1 vibrates is suppressed.

[0025] The volume resistivity of the power storage device 1 described above is preferably 1.0×10 6 Ω·cm or more.

[0026] Next, a manufacturing method of the power storage device 1 will be described. This manufacturing method includes a preparation process, an arrangement process, a welding process, and an injection process.

[0027] In the preparation process, a housing main body 210 having an insulating sheet 300 on its inner surface and a closing plate 220 having an insulating sheet 300 on its inner surface are prepared.

[0028] In the arrangement process, the power storage module 100 is arranged in the housing main body 210 having the insulating sheet 300.

[0029] In the welding process, as Figure 2 shown, the closing plate 220 is welded to the housing main body 210 to close the opening of the housing main body 210 by the closing plate 220 having the insulating sheet 300. At this time, the insulating sheet 300 covering the boundary portion 215 between the inner surface of the housing main body 210 and the inner surface of the closing plate 220 sometimes melts.

[0030] In the injection process, an insulating material having insulating properties is injected into the housing 200 from outside the housing 200 through an injection port h provided in the housing main body 210 to form a covering portion 400 covering the boundary portion 215 between the inner surface of the housing main body 210 and the inner surface of the closing plate 220. The insulating material is a material (potting material) for forming the covering portion 400. In this process, in order to improve the permeability to the boundary portion 215 (the portion where the inner surface of the housing 200 is exposed), a material having a viscosity of 5 Pa·s or more is injected as the insulating material.

[0031] As described above, in the power storage device 1 of the present embodiment, the inner surfaces of the housing main body 210 and the plugging plate 220 are covered with the insulating sheet 300, and the boundary portion 215 between the inner surface of the housing main body 210 and the inner surface of the plugging plate 220 is covered with the covering portion 400, so that insulation can be ensured.

[0032] In addition, in the above-described embodiment, instead of cooling the main surface of the power storage unit 101 from the outside of the housing 200 in the stacking direction of the power storage unit 101, the cooling device 2 cools the current collecting plate 120 and the bus bar 102 through the covering portion 400 made of potting material from the side portion of the housing 200 in a direction perpendicular to the stacking direction. Since the current collecting plate 120 and the bus bar 102 are made of metal, the power storage module 100 is effectively cooled. In addition, it is possible to reduce the size of the entire device including the power storage device 1 and the cooling device 2 in the stacking direction.

[0033] Those skilled in the art can understand that the above exemplary embodiments are specific examples of the following methods.

[0034] The power storage device in the above-described embodiment includes a housing main body, a power storage module, a plugging plate, an insulating sheet, and a covering portion. The housing main body is made of metal and has an opening in at least one direction. The power storage module is disposed in the housing main body. The plugging plate is made of metal and is welded to the housing main body so as to plug the opening of the housing main body. The insulating sheet covers the inner surfaces of the housing main body and the plugging plate. The covering portion is made of an insulating material and covers the boundary portion between the inner surface of the housing main body and the inner surface of the plugging plate.

[0035] In this power storage device, the inner surfaces of the housing main body and the plugging plate are covered with the insulating sheet, and the boundary portion between the inner surface of the housing main body and the inner surface of the plugging plate is covered with the covering portion, so that insulation can be ensured.

[0036] In addition, the volume resistivity of the power storage device is preferably 1.0×10 6 Ω·cm or more.

[0037] The manufacturing method of the electricity storage device in the above-described embodiment includes a preparation step, an arrangement step, a welding step, and an injection step. In the preparation step, a housing main body and a blocking plate are prepared. The housing main body is made of metal, has an insulating sheet on its inner surface, and is open in at least one direction. The blocking plate is made of metal, has an insulating sheet on its inner surface, and is shaped to block the opening of the housing main body. In the arrangement step, an electricity storage module is arranged in the housing main body. In the welding step, the blocking plate is welded to the housing main body in such a manner that the opening of the housing main body is blocked by the blocking plate. In the injection step, an insulating material having insulating properties is injected into the housing main body from the outside of the housing main body in such a manner as to form a covering portion that covers the boundary portion between the inner surface of the housing main body and the inner surface of the blocking plate.

[0038] In this manufacturing method, even when the insulating sheet melts at the boundary portion between the inner surface of the housing main body and the inner surface of the blocking plate in the welding step, since the boundary portion is covered by the covering portion made of the insulating material in the subsequent injection step, an electricity storage device with ensured insulating properties can be manufactured.

[0039] In addition, in the injection step, as the insulating material, it is preferable to inject a material having a viscosity of 5 Pa·s or more.

[0040] Although the embodiments of the present invention have been described, it should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is represented by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

Claims

1. A method for manufacturing a power storage device, the power storage device having a housing that houses a power storage module, the housing having a housing main body and a plugging plate, the power storage module being disposed within the housing main body, the power storage module having a plurality of power storage cells, each power storage cell being a laminated type cell and having a plurality of electrode bodies, a current collector plate, a laminated film, an adhesive member, and an electrolytic solution, and an end portion of the current collector plate protruding from the laminated film. The plurality of power storage cells are laminated in one direction, and the method for manufacturing the power storage device includes a preparation process, a configuration process, a welding process, and an injection process. In the preparation process, the housing main body and the plugging plate are prepared. The housing main body is made of metal and has an insulating sheet provided on its inner surface, that is, the inner surface of the housing main body is covered by the insulating sheet, and the housing main body is open in at least one direction and is formed in a rectangular tube shape having a central axis extending in a direction orthogonal to the lamination direction of each power storage cell. In addition, an injection port is provided on the housing main body. The plugging plate is made of metal and has an insulating sheet provided on its inner surface, that is, the inner surface of the plugging plate is covered by the insulating sheet, and the plugging plate is shaped to plug the opening of the housing main body. In the configuration process, the power storage module is disposed within the housing main body such that the extending direction of the central axis of the housing main body is orthogonal to the lamination direction of each power storage cell of the power storage module, and a restricting unit made of a material having dilatancy is disposed between the power storage module and the housing main body to restrict the relative displacement of the power storage module with respect to the housing in the lamination direction of each power storage cell. In the welding process, the plugging plate is welded to the housing main body such that the opening of the housing main body is plugged by the plugging plate, and in the welding process, the insulating sheet covering the boundary portion between the inner surface of the housing main body and the inner surface of the plugging plate melts. In the injection process, an insulating material having insulating properties is injected into the housing main body from outside the housing main body through the injection port to form a covering portion covering the boundary portion between the inner surface of the housing main body and the inner surface of the plugging plate. In the method for manufacturing the power storage device, a cooling device is further provided in contact with the plugging plate of the housing in a direction orthogonal to the lamination direction of each power storage cell.

2. The method for manufacturing a power storage device according to claim 1, wherein in the injection process, a material having a viscosity of 5 Pa·s or more is injected as the insulating material.

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