Power storage device

Abstract

Power storage device (1), with a power storage module (4); a conductive plate (5, 5A) which is intended to be laminated with the power storage module (4); and a sealing element (80) provided between the conductive plate (5, 5A) and the power storage module (4), wherein the power storage module (4) has an electrode laminate (11) with several laminated metal plates (15, 20A, 20B) and a sealing body (12) which is provided such that it surrounds a side surface of the electrode laminate (11), forms an interior space between adjacent electrodes (14, 18, 19) and seals the interior space, the several metal plates (15, 20A, 20B) have a metal plate (15) of a negative terminal electrode (18), a metal plate (15) of a positive terminal electrode (19) and metal plates (15) of several bipolar electrodes (14) which are provided between the negative terminal electrode (18) and the positive terminal electrode (19), the sealing body (12) has several resin sections (21), each of which has a frame shape and is provided at individual edge sections (15c, 20c) of the several metal plates (15, 20A, 20B) in the electrode laminate (11), the metal plates (20A, 20B) at the laminate ends of the electrode laminate (11) each have an exposed surface (20d) that is exposed by the resin section (21), the exposed surface (20d) has a contact area (20e) that is in contact with the conductive plate (5, 5A) and a non-contact area (20f) that is not in contact with the conductive plate (5, 5A), and the sealing element (80) has a first sealing section (80a) which is provided along an inner edge of the resin section (21) to be in contact with the resin section (21), adheres to the conductive plate (5, 5A) and the non-contact area (20f), fills a section between the conductive plate (5, 5A) and the non-contact area (20f) and seals a section between the conductive plate (5, 5A) and the exposed surface (20d), characterized by the fact that the conductive plate (5A) has several interconnected plate elements (50), and the sealing element (80) has a second sealing section (80b) which is provided along a coupling section (60) formed between the adjacent plate elements (50), adheres to each of the adjacent plate elements (50) and the non-contact area (20f), fills a section between each of the adjacent plate elements (50) and the non-contact area (20f) and seals the section between the conductive plate (5, 5A) and the exposed surface (20d).

Description

[0001] The present disclosure relates to a power storage device.

[0002] A power storage module with a bipolar electrode is known from the prior art, in which a positive electrode is formed on a first surface of a metal plate and a negative electrode is formed on a second surface of the metal plate (see, for example, publication JP 2011-204 386 A). The power storage module disclosed in publication JP 2011-204 386 A has an electrode laminate with a plurality of laminated bipolar batteries and a sealing body configured to seal an interior space formed between adjacent electrodes.

[0003] In a power storage device that incorporates such a power storage module, the power storage modules are laminated together by a conductive plate. The adjacent power storage modules are electrically connected to each other via this conductive plate.

[0004] In the power storage device described above, there is a case where rust forms on a metal plate positioned at one laminate end of the power storage modules. As the rust progresses, the strength of the metal plate decreases, which can lead to problems such as electrolyte leakage.

[0005] Publication WO 2019 / 171 698 A1 is considered the closest prior art. It discloses the features of the preamble of claim 1.

[0006] The object of the invention is to provide a power storage device capable of suppressing the formation and progression of rust on a metal plate at a laminate end.

[0007] A power storage device of the present disclosure comprises a power storage module, a conductive plate arranged to be laminated with the power storage module, and a sealing element provided between the conductive plate and the power storage module. The power storage module has an electrode laminate and a sealing body. The electrode laminate has a plurality of laminated metal plates. The sealing body is arranged to surround a side face of the electrode laminate. The sealing body forms an interior space between adjacent electrodes and seals the interior space. The plurality of metal plates comprises a metal plate of a negative terminal electrode, a metal plate of a positive terminal electrode, and metal plates of a plurality of bipolar electrodes provided between the negative terminal electrode and the positive terminal electrode.The sealing element has multiple resin sections, each frame-shaped and positioned at individual edge sections of multiple metal plates embedded in the electrode laminate. The metal plates at the laminate ends of the electrode laminate each have an exposed surface free of the resin section. This exposed surface has a contact area that is in contact with the conductive plate and a non-contact area that is not in contact with the conductive plate. The sealing element has a first sealing section. The first sealing section is positioned along an inner edge of the resin section to be in contact with it. The first sealing section adheres to both the conductive plate and the non-contact area, filling the gap between them.The first sealing section seals a section between the conductive plate and the exposed surface.

[0008] In this power storage device, the metal plates at the laminate end each have an exposed surface separated from the resin section. This exposed surface comprises a contact area with the conductive plate and a non-contact area. The first sealing section is positioned along the inner edge of the resin section to make contact with it, adhering to both the conductive plate and the non-contact area. This seal fills the gap between the conductive plate and the non-contact area and seals the gap between the conductive plate and the exposed surface. Therefore, it is possible to suppress the formation and progression of rust on the metal plates at the laminate ends.

[0009] The conductive plate comprises a plurality of interconnected plate elements, and the sealing element has a second sealing section. This second sealing section is provided along a coupling section formed between the adjacent plate elements. The second sealing section adheres to each of the adjacent plate elements and the non-contact area, filling the gap between each of the adjacent plate elements and the non-contact area. The second sealing section seals the area between the conductive plate and the exposed surface. In this case, a gap between the plate elements that form the conductive plate is filled by the second sealing section.Therefore, it is possible to suppress the penetration of moisture from the gap, and thus it is possible to suppress the formation and progression of rust on the metal plates at the laminate ends.

[0010] The conductive plate can have a first surface and a second surface in one lamination direction of the electrode laminate. The second sealing section can fill a gap between the adjacent plate elements and can be continuous from the first surface to the second surface. In this case, it is possible to further suppress the formation and progression of rust on the metal plates at the laminate ends.

[0011] At an end section of the coupling segment in one lamination direction of the electrode laminate, the gap between the adjacent plate elements can widen as the plate elements approach the metal plate at the laminate end. In this case, it is likely that the gap between the plate elements that configure the conductive plate will be filled by the sealing element.

[0012] The sealing element can be a liquid seal. In this case, the section between the conductive plate and the non-contact area is likely filled with the sealing element.

[0013] Viewed in the lamination direction of the electrode laminate, the resin section can overlap an outer edge of the conductive plate. In this case, it is possible to prevent the metal plates at the laminate ends from being damaged by contact with the outer edge of the conductive plate.

[0014] The power storage device can further include a sensing element coupled to an end face of the conductive plate. The first sealing section can extend from the inner edge to a position corresponding to a coupling section formed between the sensing element and the conductive plate in the metal plate at the laminate end. In this case, it is prevented that the metal plate at the laminate end enters a gap between the sensing element and the conductive plate, e.g., due to a fluctuation in the internal pressure of the power storage module. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic sectional view showing an example of a power storage device. Fig. Figure 2 is a sectional view showing the internal structure of a power storage module. Fig. Figure 3 is a top view showing the power storage module and a conductive plate on the power storage module. Fig. Figure 4 is a perspective view of a plate element of the conductive plate. Fig. Figure 5 is a perspective view of the plate element of the conductive plate. Fig. Figure 6 is a perspective view of a capture element. Fig. Figure 7 is a top view to describe the position where a sealing element is provided. Fig. 8A and Fig. Figure 8B shows sectional views describing a method for sealing an area between the plate elements with a second sealing section. Fig. 9A and Fig. Figure 9B shows sectional views to describe the procedure for sealing the area between the plate elements with the second sealing section. Fig. Figure 10 is a sectional view to describe a method for sealing a section between the power storage module and the conductive plate with a first sealing section. Fig. 11A and Fig. Figure 11B shows sectional views to describe another method for sealing the area between the plate elements with the second sealing section.

[0015] An embodiment according to the present disclosure is described in detail below with reference to the drawings. The same reference numeral is used in the description of the drawings for the same element or elements with the same function, and the elements are not described repeatedly.

[0016] Fig. Figure 1 is a schematic sectional view showing an example of a power storage device according to the present embodiment. A [missing text] in the Fig. The power storage device 1 shown is used as a battery for various types of vehicles, e.g., for a forklift, a hybrid vehicle, an electric vehicle, and the like. The power storage device 1 has a module laminate 2 with a plurality of laminated power storage modules 4 and a retaining element 3 configured to exert a retaining force on the module laminate 2 in the lamination direction of the module laminate 2. In the following description, the lamination direction of the module laminate 2 is defined as the Z-direction, a first direction perpendicular to the lamination direction is defined as the X-direction, and a second direction perpendicular to the lamination direction and to the first direction is defined as the Y-direction.

[0017] The module laminate 2 has the power storage modules 4, conductive plates 5 which are arranged to be laminated with the power storage modules 4, a detection element 70 (see Fig. 3) and a sealing element 80 (see Fig. 7) The detection element 70 and the sealing element 80 are described below. In the present embodiment, the module laminate 2 has a plurality of power storage modules 4 and a plurality of conductive plates 5. The number of power storage modules 4 is, for example, five, and the number of conductive plates 5 is, for example, four. The power storage module 4 is a bipolar battery and has a rectangular shape when viewed in the Z direction. The power storage module 4 is, for example, at least one consisting of a secondary battery, such as a nickel-metal hydride secondary battery or a lithium-ion secondary battery, and an electrical double-layer capacitor. In the following description, a nickel-metal hydride secondary battery is described as an example of a power storage module 4.

[0018] The numerous power storage modules 4 are stacked along the Z-direction through the conductive plates 5 and electrically connected in series along the Z-direction. The conductive plate 5 is, for example, a plate element made of a conductive material, such as metal. Examples of materials for the conductive plate 5 are aluminum. A plating layer of nickel or a similar material can be formed on the surface of the conductive plate 5. In the Fig. In the example shown, the area of ​​the conductive plate 5, viewed in the Z direction, is smaller than the area of ​​the power storage module 4. However, from the point of view of improving the heat dissipation properties, the area of ​​the conductive plate 5 can be the same as the area of ​​the power storage module 4 or larger than the area of ​​the power storage module 4.

[0019] The plurality of conductive plates 5 consists of several (in the present embodiment, two) conductive plates 5A, which are arranged between the power storage modules 4 arranged side by side in the Z-direction, and several (in the present embodiment, two) conductive plates 5B, which are arranged at the laminate ends of the module laminate 2. The adjacent power storage modules 4 are electrically connected to each other via the conductive plates 5A. Insulating plates B are arranged outside the conductive plates 5B. A negative electrode terminal 7 is connected to one conductive plate 5B, and a positive electrode terminal 6 is connected to the other conductive plate 5B. The positive electrode terminal 6 and the negative electrode terminal 7 are each extended, for example, from an edge region of the conductive plate 5B in the X-direction.The power storage device 1 is charged and discharged via the positive electrode terminal 6 and the negative electrode terminal 7.

[0020] A multitude of through-holes (flow paths) 5a, configured to allow a cooling fluid F (see the Fig. 3 and the Fig. 4), such as air, are provided within the conductive plate 5A arranged between the power storage modules 4. The plurality of through-holes 5a form a cooling mechanism for cooling the power storage modules 4. The conductive plate 5A functions as a connecting element, configured to electrically connect the adjacent power storage modules 4, and as a heat dissipation plate, configured to dissipate the heat generated by the power storage modules 4 by allowing the cooling fluid F to circulate through the plurality of through-holes 5a.

[0021] The retaining element 3 has a pair of end plates 8 configured to enclose the module laminate 2 in the Z-direction, as well as fastening screws 9 and nuts 10 configured to secure the end plates 8. The end plate 8 is a rectangular metal plate with an area that, viewed in the Z-direction, is slightly larger than the area of ​​the power storage module 4, the area of ​​the conductive plate 5, and the area of ​​the conductive plate 5B. An insulating plate B, with electrical insulating properties, is provided between the end plate 8 and the conductive plate 5B. This insulating plate B isolates the end plate 8 and the conductive plate 5B. Insertion holes 8a are provided in the edge regions of the end plate 8 at positions outside the module laminate 2. The fastening screw 9 extends from the insertion hole 8a of one end plate 8 to the insertion hole 8a of the other end plate 8.The nut 10 is screwed onto the distal end section of the fastening screw 9, which protrudes from the insertion bore 8a of the other end plate 8. This connects the power storage modules 4, the conductive plates 5, and the conductive plates 5B to each other via the end plates 8 and assembles them into the module laminate 2. Furthermore, a retaining force is exerted on the module laminate 2 in the Z-direction.

[0022] Next, the structure of the power storage module 4 will be described in detail. Fig. Figure 2 is a cutaway view showing the internal configuration of the power memory module. As shown in the Fig. As shown in Figure 2, the power storage module 4 has an electrode laminate 11 and resin sealing elements 12 configured to seal the electrode laminate 11. The power storage module 4 is, for example, in the shape of a cuboid.

[0023] The electrode laminate 11 has a plurality of electrodes laminated along a lamination direction (Z-direction) through separators 13 and metal plates 20A and 20B, which are arranged at the laminate ends of the electrode laminate 11. The plurality of electrodes has a laminate consisting of a plurality of bipolar electrodes 14, a negative terminal electrode 18, and a positive terminal electrode 19. The laminate of the plurality of bipolar electrodes 14 is located between the negative terminal electrode 18 and the positive terminal electrode 19.

[0024] The bipolar electrode 14 has a metal plate 15 with a first surface 15a and a second surface 15b opposite the first surface 15a, a positive electrode 16 located on the first surface 15a, and a negative electrode 17 located on the second surface 15b. The positive electrode 16 is a positive electrode active material layer formed by applying a positive electrode active material to the metal plate 15. The negative electrode 17 is a negative electrode active material layer formed by applying a negative electrode active material to the metal plate 15. In the electrode laminate 11, the positive electrode 16 in one bipolar electrode 14 faces the negative electrode 17 in the other bipolar electrode 14, which is located adjacent to the bipolar electrode in the Z-direction with the separator 13 between them.In the electrode laminate 11, the negative electrode 17 in one bipolar electrode 14 is opposite the positive electrode 16 in the other bipolar electrode 14, which lies next to the bipolar electrode in the Z direction with the separator 13 in between.

[0025] The negative terminal electrode 18 has a metal plate 15 and a negative electrode 17, which is provided on a second surface 15b of the metal plate 15. The negative terminal electrode 18 is arranged at one end of the electrode laminate 11 in the Z-direction such that the second surface 15b faces the central side of the electrode laminate 11 in the Z-direction. The metal plate 20A is further laminated onto a first surface 15a of the metal plate 15 of the negative terminal electrode 18 and is electrically connected via the metal plate 20A to a conductive plate 5 (see Fig. 1) connected next to the power storage module 4. The negative electrode 17, which is provided on the second surface 15b of the metal plate 15 of the negative terminal electrode 18, lies opposite the positive electrode 16 of the bipolar electrode 14 at one end of the electrode laminate 11 in the Z direction through the separator 13.

[0026] The positive terminal electrode 19 has a metal plate 15 and a positive electrode 16, which is provided on a first surface 15a of the metal plate 15. The positive terminal electrode 19 is arranged at the other end of the electrode laminate 11 in the Z-direction such that the first surface 15a faces the central side of the electrode laminate 11 in the Z-direction. The metal plate 20B is further laminated onto a second surface 15b of the metal plate 15 of the positive terminal electrode 19 and is electrically connected to the other conductive plate 5 via the metal plate 20B (see Figure 1). Fig. 1) connected next to the power storage module 4. The positive electrode 16, which is provided on the first surface 15a of the metal plate 15 of the positive terminal electrode 19, is opposite the negative electrode 17 of the bipolar electrode 14 at the other end of the electrode laminate 11 in the Z direction through the separator 13.

[0027] The metal plate 15 is formed, for example, from a metal such as nickel or a nickel-plated steel plate. As an example, the metal plate 15 is a rectangular nickel foil. Each metal plate 15 is one of the metal plates contained in the electrode laminate 11. An edge section 15c of the metal plate 15 has a rectangular frame shape and is an unapplied area onto which neither a positive electrodeactive material nor a negative electrodeactive material is applied. Examples of the positive electrodeactive material that forms the positive electrode 16 include nickel hydroxide. Examples of the negative electrodeactive material that forms the negative electrode 17 include a hydrogen storage alloy.In the present embodiment, the area where the negative electrode 17 is formed on the second surface 15b of the metal plate 15 is slightly larger than the area where the positive electrode 16 is formed on the first surface 15a of the metal plate 15. The electrode laminate 11 has a plurality of laminated metal plates 15, 20A and 20B.

[0028] The separator 13 is an element for preventing a short circuit between the metal plates 15 and is, for example, in the form of a film. Examples of separators 13 include a porous film made of a polyolefin-based resin such as polyethylene (PE) or polypropylene (PP), a woven or nonwoven fabric made of polypropylene, methylcellulose, or similar materials, and the like. The separator 13 can also be a separator reinforced with a vinylidene fluoride resin compound. It should be noted that the separator 13 is not limited to the plate form, and a bag-shaped separator can also be used.

[0029] The metal plates 20A and 20B are essentially the same elements as the metal plate 15 and consist, for example, of metal such as nickel or a nickel-plated steel plate. Each of the metal plates 20A and 20B is one of the metal plates contained in the electrode laminate 11. For example, the metal plates 20A and 20B are rectangular nickel foils. The metal plates 20A and 20B are unapplied electrodes, in which neither a positive electrodeactive material layer nor a negative electrodeactive material layer is applied to a first surface 20a and a second surface 20b.

[0030] Metal plate 20A is located at one end of the electrode laminate 11. Due to metal plate 20A, the negative terminal electrode 18 is positioned between metal plate 20A and the bipolar electrode 14 along the Z-direction. Metal plate 20B is located at the other end of the electrode laminate 11. Due to metal plate 20B, the positive terminal electrode 19 is positioned between metal plate 20B and the bipolar electrode 14 along the Z-direction. Within the electrode laminate 11, the central region (the areas containing active material layers in the bipolar electrodes 14, the negative terminal electrode 18, and the positive terminal electrode 19) is extended along the Z-direction compared to the surrounding region.Therefore, the metal plates 20A and 20B are bent in a direction in which the central areas of the metal plates 20A and 20B are separated from each other. The central areas of the first surface 20a of metal plate 20A and the second surface 20b of metal plate 20B are in contact with the conductive plates 5.

[0031] The sealing body 12 is formed, for example, from an insulating resin in a rectangular cylindrical shape as a whole. The sealing bodies 12 are designed to surround side surfaces 11a of the electrode laminate 11. The sealing bodies 12 hold the edge regions 15c against the side surfaces 11a. The sealing body 12 has a plurality of frame-shaped first sealing parts 21 (resin sections), each positioned at the edge sections of the metal plates contained in the electrode laminate 11 (i.e., the edge sections 15c of metal plates 15 and the edge sections 20c of metal plates 20A and 20B), and a second sealing part 22, which surrounds the first sealing parts 21 from the outside along the side surface 11a and is connected to each of the first sealing parts 21. The first sealing parts 21 and the second sealing part 22 are, for example, an alkali-resistant insulating resin.Examples of a material that forms the first sealing parts 21 and the second sealing part 22 are polypropylene (PP), polyphenylene sulfide (PPS), modified polyphenylene ether (modified PPE) and the like.

[0032] The first sealing element 21 extends continuously around the entire circumference of at least the edge section 15c of the metal plate 15 and the edge section 20c of the metal plate 20A or 20B and has a rectangular frame shape when viewed in the Z direction. The first sealing element 21 is welded and airtightly connected to the edge section 15c of the metal plate 15 or the edge section 20c of the metal plate 20A or 20B, for example, by ultrasonic waves and / or heat. The first sealing element 21 has an outer side section 21a that projects beyond the edge of the metal plate 15 or the metal plate 20A or 20B, and an inner side section 21b that is located within the edge of the metal plate 15 or the metal plate 20A or 20B. The distal end sections (outer edge sections) of the outer side sections 21a of the first sealing parts 21 are connected to the second sealing part 22 by a weld layer 23. The weld layer 23 is, for example,The first sealing parts 21 are formed by welding their distal end sections together using hot plate welding. The outer side sections 21a of the first sealing parts 21, which abut each other along the Z-direction, can be separate from each other or in contact with each other. Furthermore, the outer side sections 21a of the first sealing parts 21, which lie next to each other along the Z-direction, can be joined together, for example, by hot plate welding.

[0033] The majority of the first sealing parts 21 has a majority of first sealing parts 21A provided at the bipolar electrodes 14 and the positive terminal electrode 19, a first sealing part 21B provided at the negative terminal electrode 18, a first sealing part 21C provided at the metal plate 20A, and first sealing parts 21D and 21E provided at the metal plate 20B.

[0034] The first sealing elements 21A are connected to the first surfaces 15a of the metal plates 15 of the bipolar electrodes 14 and the positive terminal electrode 19. The inner side section 21b of the first sealing element 21A is positioned between the edge sections 15c of the metal plates 15, which lie next to each other in the Z-direction. An area where the edge section 15c on the first surface 15a of the metal plate 15 and the first sealing element 21A overlap forms a connection area between the metal plate 15 and the first sealing element 21A.

[0035] In the present embodiment, the first sealing part 21A is formed from a half-folded film and thus has a two-layer structure. The outer edge section of the first sealing part 21A, which is embedded in the second sealing part 22, is the folded (curved) section of the film. The film in the first layer, which forms the first sealing part 21A, is bonded to the first surface 15a. The inner edge of the film in the second layer lies outside the inner edge of the film in the first layer and forms a stepped section onto which the separating part 13 is placed. The inner edge of the film in the second layer is positioned within the edge of the metal plate 15.

[0036] The first sealing element 21B is connected to the first surface 15a of the metal plate 15 of the negative terminal electrode 18. The inner side section 21b of the first sealing element 21B is arranged side by side in the Z-direction between the edge section 15c of the metal plate 15 of the negative terminal electrode 18 and the edge section 20c of the metal plate 20A. An area where the edge section 15c on the first surface 15a of the metal plate 15 and the inner side section 21b of the first sealing element 21B overlap forms a connection area between the metal plate 15 and the first sealing element 21B. The first sealing element 21B is also connected to the second surface 20b of the metal plate 20A. An area where the edge section 20c on the second surface 20b of the metal plate 20A and the first sealing part 21B overlap forms a connection area between the metal plate 20A and the first sealing part 21B.In the present embodiment, the first sealing part 21B is also connected to the edge section 20c on the second surface 20b of the metal plate 20A.

[0037] The first sealing element 21C is connected to the first surface 20a of the metal plate 20A. In the present embodiment, the first sealing element 21C is arranged closer to an end face in the Z-direction than all other first sealing elements 21. Among the multiple first sealing elements 21, the first sealing element 21C is the first sealing element located at an end face in the Z-direction. An area where the edge section 20c on the first surface 20a of the metal plate 20A and the first sealing element 21C overlap forms a connection area between the metal plate 20A and the first sealing element 21C.

[0038] In the present embodiment, the outer edge sections of the first sealing parts 21B and 21C, which are embedded in the second sealing part 22, are continuously connected to one another. That is, the first sealing parts 21B and 21C are formed from a film that is folded in half, with the edge section 20c of the metal plate 20A sandwiched between them. The outer edge section of the first sealing parts 21B and 21C is the folded (bent) section of the film. The film forming the first sealing parts 21B and 21C is connected to the edge section 20c on both the first surface 20a and the second surface 20b of the metal plate 20A. As described above, both surfaces of the metal plate 20A are connected to the first sealing parts 21B and 21C, making it possible to suppress the leakage of the electrolyte solution, which is due to a so-called alkaline creep phenomenon.

[0039] The first sealing element 21D is connected to the first surface 20a of the metal plate 20B. The inner side section 21b of the first sealing element 21D is arranged side by side in the Z-direction between the edge section 15c of the metal plate 15 of the positive terminal electrode 19 and the edge section 20c of the metal plate 20B. An area where the edge section 20c on the first surface 20a of the metal plate 20B and the first sealing element 21D overlap forms a connection area between the metal plate 20B and the first sealing element 21D.

[0040] The first sealing element 21E is arranged on the edge section 20c on the second surface 20b of the metal plate 20B. In the present embodiment, the first sealing element 21E is arranged closer to the other end face in the Z-direction than all other first sealing elements 21. Furthermore, in the present embodiment, the first sealing element 21E is not connected to the metal plate 20B.

[0041] The metal plate 20A, positioned at the laminate end, has an exposed surface 20d that is exposed by the first sealing element 21. The first surface 20a of the metal plate 20A has the exposed surface 20d that is exposed by the first sealing element 21C. The second surface 20b of the metal plate 20B has an exposed surface 20d that is exposed by the first sealing element 21E. The exposed surfaces 20d each have a contact area 20e (see, for example, Figure 1). Fig. 10), which is in contact with (abuts) the conductive plate 5 and is electrically connected to the conductive plate 5, and a non-contact area (contactless area) 20f (see e.g. Fig. 10), which is not in contact (not touching) with the conductive plate 5.

[0042] In the present embodiment, the outer edge sections of the first sealing parts 21D and 21E, which are embedded in the second sealing part 22, are continuously connected to one another. That is, the first sealing parts 21D and 21E are formed from a film that is folded in half, with the edge section 20c of the metal plate 20B sandwiched between them. The outer edge section of the first sealing parts 21D and 21E is the folded section (bent section) of the film. The film forming the first sealing parts 21D and 21E is connected to the edge section 20c on both the first surface 20a and the second surface 20b of the metal plate 20B.

[0043] In the welding areas, the surfaces of metal plates 15, 20A, and 20B are roughened. The roughened areas could be only the bonding areas; however, in the present embodiment, the first surface 15a of metal plate 15 is completely roughened. Furthermore, the first surface 20a and the second surface 20b of metal plate 20A are completely roughened. Additionally, the first surface 20a of metal plate 20B is completely roughened.

[0044] The roughening can be achieved, for example, by creating numerous protrusions through electroplating. Due to the multitude of protrusions formed in the bonding areas, the resin, in its molten state, penetrates the bonding interfaces with the first sealing element 21 into the spaces between these protrusions, resulting in an anchoring effect. This improves the respective bond strengths between the metal plates 15, 20A, and 20B and the first sealing elements 21. The protrusion formed during roughening has a shape that, for example, increases in thickness from the proximal end to the distal end. Therefore, the cross-sectional shape between the adjacent protrusions becomes an undercut shape, further enhancing the anchoring effect.

[0045] The second sealing elements 22 are located outside the electrode laminate 11 and the first sealing elements 21 to surround the side surfaces 11a of the electrode laminate 11 and to form the outer walls (housing) of the power storage module 4. The second sealing elements 22 are formed, for example, by injection molding a resin and extend along the Z-direction over the entire length of the electrode laminate 11. The second sealing element 22 has a rectangular frame shape that extends along the Z-direction as the axial direction. The second sealing elements 22 are welded to the outer surfaces of the first sealing elements 21, for example, by the heat generated during injection molding.

[0046] The sealing element 12 forms an interior space V between the electrodes located P and seals this interior space V. More precisely, the second sealing elements 22, together with the first sealing elements 21, seal the spaces between the bipolar electrodes 14, which lie next to each other along the Z-direction; the spaces between the negative terminal electrode 18 and the bipolar electrode 14, which lie next to each other along the Z-direction; and the spaces between the positive terminal electrode 19 and the bipolar electrode 14, which lie next to each other along the Z-direction. Therefore, airtight compartments V are formed between the adjacent bipolar electrodes 14, between the negative terminal electrode 18 and the bipolar electrode 14, and between the positive terminal electrode 19 and the bipolar electrode 14.These interior spaces V contain, for example, an electrolytic solution (not shown) containing an alkaline solution such as an aqueous potassium hydroxide solution. The separators 13, the positive electrodes 16, and the negative electrodes 17 are impregnated with the electrolytic solution. The sealing element 12 also seals the area between the metal plate 20A and the negative end electrode 18, and the area between the metal plate 20B and the positive end electrode 19.

[0047] Next, the detailed configuration of the conductive plate 5 described above will be described. Fig. Figure 3 is a top view showing the power storage module 4 and the conductive plate 5A on the power storage module 4. As shown in the Fig. As shown in Figure 3, the conductive plate 5A has a rectangular shape with an area slightly smaller than the planar shape of the power storage module 4 when viewed in the Z direction (i.e., in a top view). The conductive plate 5A is positioned within the frame of the second sealing parts 22. In the present embodiment, the conductive plate 5A has a rectangular shape comprising a pair of long sides 5b and 5c, and a pair of short sides 5d and 5e. The pair of long sides 5b and 5c extends along the X direction and is opposite each other in the Y direction. The pair of short sides 5d and 5e extends along the Y direction and is opposite each other in the X direction.

[0048] In the present embodiment, the pair consisting of long sides 5b and 5c, and the pair consisting of short sides 5d and 5e, form the outer edge of the conductive plate 5A. The pair consisting of long sides 5b and 5c overlaps the first sealing elements 21 in the Z-direction. The pair consisting of short sides 5d and 5e does not overlap the first sealing elements 21 in the Z-direction. The first sealing elements 21 arranged on the pair consisting of short sides 5d and 5e are designed to extend further inward than the first sealing elements 21 arranged on the pair consisting of long sides 5b and 5c.The lengths in the X direction of the first sealing parts 21, which are arranged on the pair of short side 5d and short side 5e, are longer than the lengths in the Y direction of the first sealing parts 21, which are arranged on the pair of long side 5b and long side 5c.

[0049] The conductive plate 5A further has a first surface 5f and a second surface 5g (see Fig. 8A) in the thickness direction (Z-direction). The first surface 5f is in contact with the metal plate 20B, which is located at the laminate end of the power storage module 4 adjacent to the conductive plate 5A on one side in the Z-direction. The second surface 5g is in contact with the metal plate 20A, which is located at the laminate end of the power storage module 4 adjacent to the conductive plate 5A on the other side in the Z-direction. As described above, in the electrode laminate 11, since the central region of the electrode laminate 11 is extended in the Z-direction compared to the surrounding region, the central regions of the first surface 5f and the second surface 5g are in contact with the central regions of the first surface 20a of the metal plate 20A and the second surface 20b of the metal plate 20B, respectively.The conductive plates 5A are arranged in contact with the metal plates 20A and 20B, which are located next to the conductive plates 5A at the laminate ends of the power storage modules 4, and electrically connect the multitude of power storage modules 4 in series.

[0050] The sensing elements 70 are connected to the end face on the short side 5d and the end face on the short side 5e of the conductive plate 5A, respectively. Examples of the sensing element 70 include an element configured to detect the temperature of the power storage module 4, an element configured to detect the voltage output by the power storage module 4, and a sensor configured to monitor the state of the power storage module 4. The sensing element 70 is, for example, made of an alkali-resistant insulating resin such as polypropylene (PP) of the same thickness as the conductive plate 5A.

[0051] The conductive plate 5A has a plurality of (in the present embodiment four) plate elements 50, which are arranged along the X-direction and coupled together. Each plate element 50 has a rectangular shape when viewed in the Z-direction (i.e., in a top view). In the present embodiment, each plate element 50 has a rectangular shape that, when viewed in the Z-direction, has a pair of long sides along the Y-direction and a pair of short sides along the X-direction. The individual plate elements 50 are arranged along the X-direction such that the long sides of adjacent plate elements 50 face each other in the X-direction.

[0052] The plate element 50 has a first surface 50a and a second surface 50b in the thickness direction (Z-direction). The first surface 50a configures a part of the first surface 5f. The second surface 50b configures a part of the second surface 5g.

[0053] The plate element 50 further comprises a pair of end faces 50c and 50d, which are opposite each other in the X-direction, and a pair of end faces 50e and 50f, which are opposite each other in the Y-direction. Each of end faces 50c and 50d is a planar surface that encloses the long side of the plate element 50 and lies along the YZ-plane. Each of end faces 50c and 50d extends along the Y-direction. End face 50c is positioned on the side of the short side 5d in the X-direction, and end face 50d is positioned on the side of the short side 5e in the X-direction. Between two plate elements 50 adjacent in the X-direction, the end surface 50c of one plate element 50 and the end surface 50d of the other plate element 50 face each other in the X-direction.

[0054] Each of the end faces 50e and 50f is a flat surface that encloses the short side of the plate element 50 and extends along the XZ plane. Each of the end faces 50e and 50f extends along the X direction. End face 50e is positioned on the long side 5b and connects one end of end face 50c and one end of end face 50d in the Y direction. End face 50f is positioned on the long side 5c and connects the other end of end face 50c and the other end of end face 50d in the Y direction. In the individual plate elements 50, the positions of the individual end faces 50e and 50f are aligned in the Y direction.

[0055] The plurality of plate elements 50 consists of a plurality of (in the present embodiment, three) plate elements 50A and one plate element 50B. In the present embodiment, the plate element 50B is arranged on the short side 5d of the plurality of plate elements 50A. The end surface 50c of the plate element 50B that is closest to the short side 5d forms the end surface of the conductive plate 5A on the short side 5d. The end surface 50d of the plate element 50A that is closest to the short side 5e forms the end surface of the conductive plate 5A on the short side 5e.

[0056] The Fig. Figure 4 is a perspective view of plate element 50A of the conductive plate 5A. Fig. Figure 5 is a perspective view of plate element 50B of the conductive plate 5A. As shown in the Fig. 4 and the Fig. As shown in Figure 5, the plate elements 50A and 50B have the plurality of through holes 5a described above. The individual through holes 5a penetrate the inner surface of the plate element 50 in the Y-direction from the end face 50e to the end face 50f of the plate elements 50A and 50B and are arranged along the X-direction. The cross-sectional shape of each through hole 5a, viewed in the Y-direction, is, for example, a rectangular shape with a longitudinal direction in the X-direction. The cooling fluid F circulates in each through hole 5a. The cooling fluid F circulates in the individual through holes 5a in the Y-direction, for example, from the side of the end face 50e to the side of the end face 50f of the plate elements 50A and 50B.

[0057] As in the Fig. As shown in Figure 4, the plate element 50A has a projecting section (projection section) 61, which is provided at the end face 50d, and a recessed section (recessed section) 62, which is provided at the end face 50c. The projecting section 61 and the recessed section 62 are formed in shapes that fit together. The projecting section 61 extends from one end to the other end of the end face 50d of the plate element 50A in the Y-direction and has the same XZ cross-sectional shape from one end to the other end of the end face 50d in the Y-direction. That is, the XZ cross-sectional shape of the projecting section 61 is uniform in the Y-direction. The projecting section 61 projects linearly along the X-direction from the central section of the end face 50d of the plate element 50A in the Z-direction.

[0058] The recess section 62 extends in the Y-direction from one end to the other end of the end surface 50c and has the same XZ section shape in the Y-direction from one end to the other end of the end surface 50c. That is, the XZ section shape of the recess section 62 is uniform in the Y-direction. The recess section 62 has a pair of wall sections 62a that overhang linearly in the Z-direction from each end section of the end surface 50c along the X-direction. Two plate elements 50A, which lie next to each other in the X-direction, are coupled together, with the projection section 61 of one plate element 50A and the recess section 62 of the other plate element 50A being adapted to each other to configure a coupling section 60 (see Fig. 8B).

[0059] The plate element 50B differs from the plate element 50A (see Fig. 4) with regard to the fact that, as in Fig. 5 is shown, instead of the recess section 62 (see Fig. 4) the projecting section 61 is provided on the end surface 50c. The plate element 50B is identical to the plate element 50A with respect to the other aspects. The plate element 50A and the plate element 50B, which lie next to each other in the X-direction, are coupled to each other, with the recessed section 62 of the plate element 50A and the projecting section 61 of the plate element 50B being adapted to each other to form a coupling section 60.

[0060] The coupling of the plate elements 50A and 50B forms a plurality of gaps G (three in the present embodiment) on each of the first surface 5f and the second surface 5g of the conductive plate 5A. The gaps G are formed between two adjacent plate elements 50A and between adjacent plate elements 50A and 50B. The gaps G extend in the Y direction along the end face 50d and connect the short side 5d and the short side 5e.

[0061] The Fig. Figure 6 is a perspective view of the capture element. Fig. Figure 6 shows the sensing element 70, which is connected to the short side 5d of the conductive plate 5A, but the sensing element 70, which is connected to the short side 5e of the conductive plate 5A, also has the same configuration. As shown in the Fig. As shown in Figure 6, the sensing element 70 has, for example, a rectangular shape when viewed in the Z direction (i.e., in a top view). In the present embodiment, the sensing element 70, viewed in the Z direction, has a rectangular shape with a pair of long sides along the Y direction and a pair of short sides along the X direction. The sensing element 70 has a first surface 70a and a second surface 70b in the thickness direction (Z direction). The first surface 70a configures the same plane as, for example, the first surface 5f. The second surface 70b configures the same plane as, for example, the second surface 5g.

[0062] The detection element 70 further comprises a pair of end faces 70c and 70d, which are opposite each other in the X-direction, and a pair of end faces 70e and 70f, which are opposite each other in the Y-direction. Each of the end faces 70c and 70d is a planar surface that encloses the long side of the detection element 70 and is located along the YZ-plane. Each of the end faces 70c and 70d extends along the Y-direction. End face 70c is positioned on the side of the conductive plate 5, and end face 70d is positioned opposite the conductive plate 5.

[0063] Each of the end faces 70e and 70f is a planar surface that encloses the short side of the capture element 70 and extends along the XZ plane. Each of the end faces 70e and 70f extends along the X direction. End face 70e is positioned on the long side 5b, and end face 70f is positioned on the long side 5c. End face 70e configures the same plane as, for example, each end face 50e. End face 70f forms the same plane as, for example, each end face 50f.

[0064] The sensing element 70 has a recess section 62 at its end face 70c. The sensing element 70 on the short side 5d of the conductive plate 5A is coupled to the plate element 50B adjacent to the sensing element 70 in the X-direction, wherein the recess section 62 of the sensing element 70 and the projecting section 61 of the plate element 50B are fitted together to configure a coupling section 60. The sensing element 70 on the short side 5e of the conductive plate 5A is coupled to the plate element 50A adjacent to the sensing element 70 in the X-direction, wherein the recess section 62 of the sensing element 70 and the projecting section 61 of the plate element 50A are fitted together to configure a coupling section 60.

[0065] Although not shown, the conductive plate 5B consists of a single plate element. The conductive plate 5B has a rectangular shape with the same area as the planar shape of, for example, a coupled body in which the conductive plate 5A and the pair of sensing elements 70 are coupled together in the Z-direction, and is arranged within the frame of the second sealing part 22.

[0066] Next, the sealing element 80 described above (see Fig. 7) described. The sealing element 80 consists, for example, of a resin. The sealing element 80 consists, for example, of a material that does not contain low molecular weight siloxane. In this case, relay contact failures are suppressed. The sealing element 80 consists, for example, of a material that is not readily hydrolyzable. In this case, a decrease in adhesion due to moisture is suppressed. The sealing element 80 consists, for example, of modified silicone. The sealing element 80 is, for example, a liquid-form gasket. In the present embodiment, the sealing element 80 is an insulating resin, but can also be a conductive resin. The sealing element 80 is provided between the conductive plate 5 and the power storage module 4.The sealing element 80 is provided between the conductive plate 5 and each of the metal plates 20A and 20B at the laminate end of the power storage module 4 and connects (bonds) the conductive plate 5 and the metal plate 20A or 20B to each other. The... Fig. The module laminate 2 shown in Figure 1 is formed, for example, by successively laminating the conductive plates 5 and the power storage modules 4 from below. At the time of lamination, the sealing element 80 is in an uncured liquid state between the conductive plate 5 and the power storage module 4. Therefore, the sealing element 80 can conform to the surface irregularities. The sealing element 80 is applied, for example, using a dispenser.

[0067] Specifically, the sealing element 80 is first positioned at a predetermined location on the conductive plate 5B, which is located at a lamination position. Then, the power storage module 4 is laminated onto the conductive plate 5B, and the conductive plate 5B and the power storage module 4 are connected by the sealing element 80. Subsequently, the sealing element 80 is placed at a predetermined location on the power storage module 4. Then, the conductive plate 5A is laminated onto the power storage module 4, and the power storage module 4 and the conductive plate 5A are connected by the sealing element 80. Similarly, the process of sequentially laminating the power storage module 4 and the conductive plate 5A is repeated while the sealing element 80 is placed at a predetermined location.

[0068] Finally, the gasket element 80 is positioned at a predetermined location on the uppermost power storage module 4. Then, the conductive plate 5B is laminated onto the power storage module 4, and the power storage module 4 and the conductive plate 5B are joined using the gasket element 80. After all conductive plates 5 and power storage modules 4 have been laminated, the gasket elements 80 are cured to form the module laminate 2. While the conductive plates 5 and power storage modules 4 are being laminated, the gasket elements 80 remain liquid, so it is unlikely that surface pressure will be exerted on the conductive plates 5 and the power storage modules 4. Therefore, a liquid-form gasket (surface gasket) is chosen as the gasket element 80, which has a long curing time and does not harden during lamination.

[0069] The Fig. Figure 7 is a top view illustrating the position where the sealing element 80 is located. Fig. Figure 7 shows the sealing element 80 provided on the power storage module 4, which is not the uppermost power storage module 4 (corresponding to the sealing element 80 provided between the conductive plate 5A and the metal plate 20A of the power storage module 4 in the module laminate 2), in the method for forming the module laminate 2 described above. The sealing element 80 has a first sealing section 80a and a plurality of (in the present embodiment, three) second sealing sections 80b. The first sealing section 80a is provided circularly along an inner edge 21c of the first sealing part 21 on the exposed surface 20d of the first surface 20a of the metal plate 20A, in order to be in contact with the first sealing part 21 provided on the edge section 20c of the metal plate 20A.The second sealing sections 80b are provided along the connecting sections 60, which are formed adjacent to each other between the plate elements 50 (see . Fig. 3).

[0070] The first sealing section 80a, for example, has a rectangular ring shape and extends continuously around the entire circumference of the first sealing part 21. The first sealing section 80a provides an airtight seal between the power storage module 4 and the conductive plate 5. The second sealing section 80b extends along the Y-direction. The two end sections of the second sealing section 80b are connected to the first sealing section 80a. The second sealing section 80b provides an airtight seal between the adjacent plate elements 50.

[0071] Although not shown, in the above described method for forming the module laminate 2, the sealing element 80 provided on the conductive plate 5A (corresponding to the sealing element 80 provided between the conductive plate 5A and the metal plate 20B of the power storage module 4 in the module laminate 2) is provided in the same way as the sealing element 80 provided on the power storage module 4, which is not the uppermost power storage module 4.The sealing element 80 provided on the uppermost power storage module 4 (corresponding to the sealing element 80 provided between the conductive plate 5B and the metal plate 20A of the power storage module 4 in the module laminate 2) and the sealing element 80 provided on the conductive plate 5B (corresponding to the sealing element 80 provided between the conductive plate 5B and the metal plate 20B of the power storage module 4 in the module laminate 2) do not have the second sealing section 80b, since the conductive plate 5B consists of a plate-like element.

[0072] A method for sealing the section between the plate elements 50A with the second sealing section 80b is described with reference to the Fig. 8A, the Fig. 8B, the Fig. 9A and the Fig. 9B described. Fig. Figure 8A shows a configuration in which the second sealing section 80b is provided on the power storage module 4. The second sealing section 80b is provided on an end section of the coupling section 60 in the Z-direction corresponding to the gap G formed between the adjacent plate elements 50A. The gaps G are formed on both end sections of the coupling section 60 in the Z-direction. The second sealing section 80b is provided in accordance with the gap G on the side of the metal plate 20A (the side of the second surface 5g). The second sealing section 80b is designed to overlap the gap G on the side of the metal plate 20A when viewed in the Z-direction. In the present embodiment, the gap G is formed between the end section of the end surface 50d in the Z-direction and the distal end section of the wall section 62a.The end section of the end surface 50d in the Z-direction and the distal end section of the wall section 62a each have a chamfered shape (an R-shape or a rounded shape). Therefore, at the end section of the coupling section 60 in the Z-direction, the distance between the adjacent plate elements 50A becomes wide as the plate elements 50A approach the metal plates 20A and 20B.

[0073] The Fig. Figure 8B shows a state in which the conductive plate 5A has been laminated onto the power storage module 4. As shown in the Fig. As shown in Figure 8B, when the conductive plate 5A is laminated onto the metal plate 20A, the second sealing section 80b enters the section between the plate elements 50A and seals the section between the plate elements 50A in the coupling section 60. The sealing element 80 is guided on the inside of the gap G on the side of the metal plate 20A along the chamfered shape of the end section of the end surface 50d in the Z-direction and the chamfered shape of the distal end section of the wall section 62a. The gap G on the side of the metal plate 20A is closed by the second sealing section 80b. The second sealing section 80b enters the gap G and, by extending more than necessary on the metal plate 20A, suppresses any deterioration in conductivity.On the exposed surface 20d in the first surface 20a of the metal plate 20A, the section corresponding to the gap G on the side of the metal plate 20A becomes the non-contact area 20f.

[0074] The Fig. Figure 9A shows a state in which the sealing element 80 is provided on the conductive plate 5A. As shown in the Fig. As shown in Figure 9A, the second sealing section 80b is positioned in accordance with the gap G on the side of the metal plate 20B. At this point, the distance between the adjacent plate elements 50A at the end section of the coupling section 60 in the Z-direction becomes wide as the plate elements 50A approach the metal plates 20A and 20B, thus making it easy to identify the position of the gap G. Therefore, it is possible to easily provide the second sealing section 80b.

[0075] The Fig. Figure 9B shows a sectional view depicting a state in which the power storage module 4 has been laminated onto the conductive plate 5A. As shown in the Fig. As shown in Figure 9B, when the power storage module 4 is laminated onto the conductive plate 5A, the second sealing section 80b enters the section between the plate elements 50A and seals the section between the plate elements 50A in the coupling section 60. The second sealing section 80b is guided on the inside of the gap G on the side of the metal plate 20B along the chamfered shape of the end section of the end surface 50d in the Z-direction and the chamfered shape of the distal end section of the wall section 62a. The gap G on the side of the metal plate 20B is closed with the second sealing section 80b. In this case as well, the second sealing section 80b enters the gap G and, by extending more than necessary on the metal plate 20B, suppresses any deterioration in conductivity.The area between the adjacent plate elements 50A is sealed airtight with the second sealing section 80b in the manner described above.

[0076] On the exposed surface 20d of the second surface 20b of the metal plate 20B, the section corresponding to the gap G on the side of the metal plate 20B becomes the non-contact area 20f. The second sealing section 80b is provided along the connecting section 60 between the adjacent plate elements 50A on both the side of the metal plate 20A and the side of the metal plate 20B. On both the side of the metal plate 20A and the side of the metal plate 20B, the second sealing section 80b adheres to each of the adjacent plate elements 50A and the non-contact area 20f, filling the area between each of the adjacent plate elements 50A and the non-contact area 20f. Here, the second sealing section 80b on the side of the metal plate 20A and the second sealing section 80b on the side of the metal plate 20B are separated from each other and not continuously connected to each other.In particular, the second sealing section 80b adheres to the end section of the end surface 50d in the Z-direction, the distal end section of the wall section 62a, and the non-contact area 20f, and fills the section between the end section of the end surface 50d in the Z-direction, the distal end section of the wall section 62a, and the non-contact area 20f. The end section of the end surface 50d in the Z-direction and the distal end section of the wall section 62a are sections that form the individual edges of the plate element 50A at the end section of the coupling section 60 in the lamination direction D.

[0077] With reference to the Fig. Section 10 describes a method for sealing the section between the power storage module 4 and the conductive plate 5A with the first sealing section 80a. Fig. Figure 10 shows a state in which the conductive plate 5A and the sensing element 70 have been laminated onto the power storage module 4. The conductive plate 5A and the sensing element 70 are coupled together. As described above, the end faces of the short side 5d overlap (see the Fig. 3) and the end face on the side of the short side 5e (see the Fig. 3) the conductive plate 5A, to which the detection element 70 is coupled, is not the first sealing part 21 when viewed in the Z direction. As in the Fig. As shown in Figure 10, the first sealing section 80a extends from the inner edge 21c of the first sealing part 21 in the metal plate 20A to the position corresponding to the coupling section 60 formed between the sensing element 70 and the conductive plate 5A, and is connected to the conductive plate 5A. Therefore, the area between the power storage module 4 and the conductive plate 5A is hermetically sealed by the first sealing section 80a. The first sealing section 80a adheres to the conductive plate 5A and the non-contact area 20f, fills the section between the conductive plate 5A and the non-contact area 20f, and hermetically seals the section between the conductive plate 5A and the exposed surface 20d.

[0078] The sealing element 80, for example, is made of modified silicone, and modified silicone does not adhere to a polyolefin-based plastic material such as polypropylene (PP), which has a low surface free energy (polarity). This means that the sealing element 80 made of modified silicone does not bond with the sensing element 70 made of such a plastic material. It should be noted that the adhesion of the sealing element 80 is achieved through the anchoring action of the sealing element 80, which breaks into the surface irregularities, and through an (intermolecular) physical interaction.

[0079] The first sealing section 80a can be formed by laminating the conductive plate 5A and the sensing element 70 onto the metal plate 20A, or it can be applied to the metal plate 20A in a form in which the first sealing section 80a has been pre-spread. The first sealing section 80a enters the gap G on the side of the metal plate 20A, which is formed at the end section of the coupling section 60 in the Z-direction, thereby suppressing the spreading of the first sealing section 80a on the metal plate 20A more than necessary. Therefore, a deterioration of conductivity is prevented.

[0080] As described above, in the power storage device 1, the metal plates 20A and 20B, which are arranged at the laminate ends of the electrode laminate 11, have exposed surfaces 20d, which are exposed by the first sealing elements 21. The exposed surface 20d has the contact area 20e, which is in contact with the conductive plate 5 and electrically connected to it, and the non-contact area 20f, which is not in contact with the conductive plate 5. The first sealing section 80a of the sealing element 80 is provided along the inner edge 21c to be in contact with the first sealing element 21. The first sealing section 80a fills the area between the conductive plate 5 and the non-contact area 20f and seals the area between the conductive plate 5 and the exposed surface 20d airtight.Therefore, it is possible to suppress the ingress of humid air and / or external moisture into the area between the exposed surface 20d of metal plate 20A and the conductive plate 5, as well as into the area between the exposed surface 20d of metal plate 20B and the conductive plate 5. This makes it possible to suppress the formation and progression of rust on metal plates 20A and 20B.

[0081] The conductive plate 5A has a plurality of plate elements 50 that are coupled together. The second sealing sections 80b of the sealing elements 80 are provided along the coupling sections 60 between the adjacent plate elements 50 on the exposed surfaces 20d of the metal plates 20A and 20B. The second sealing section 80b adheres to each of the adjacent plate elements 50 and the non-contact area 20f, fills the section between each of the adjacent plate elements 50 and the non-contact area 20f, and seals the section between the conductive plate 5 and the exposed surface 20d.Therefore, the columns G are filled with the second sealing sections 80b, thus preventing moisture from entering the section between the exposed surface 20d of metal plate 20A and conductive plate 5A, and the section between the exposed surface 20d of metal plate 20B and conductive plate 5A, from the columns G. Furthermore, since the columns G are filled with the sealing elements 80 and the columns G are closed, the ingress of moisture from metal plates 20A and 20B into the columns G due to fluctuations in the internal pressure of the power storage module 4 is prevented.

[0082] At the end section of the coupling section 60 in the Z-direction, the gap between the adjacent plate elements 50 widens as the plate elements 50 approach the metal plates 20A and 20B. Since, as described above, the openings of the gaps G are wide, it is easy to fill the gaps G between the plate elements 50, which form the conductive plate 5A, with the sealing elements 80. Even if the positional accuracy at the time of deployment of the sealing element 80 is low, it is possible, for example, to infiltrate the interior of the gap G and close the gap G.

[0083] Viewed in the Z direction, the first sealing element 21 overlaps the pair of long sides 5b and 5c, which form part of the outer edge of the conductive plate 5. Therefore, it is possible to prevent damage to the metal plates 20A and 20B due to contact with the pair of long sides 5b and 5c of the conductive plate 5.

[0084] The first sealing sections 80a extend in the metal plates 20A and 20B from the inner edges 21c of the first sealing parts 21 to the position corresponding to the coupling sections 60 between the sensing element 70 and the conductive plate 5A. This prevents the metal plates 20A and 20B from entering gaps between the sensing elements 70 and the conductive plates 5A, for example, due to fluctuations in the internal pressure of the power storage module 4. In the present embodiment, the first sealing parts 21 on the sides of the pair of short sides 5d and 5e, which are provided with the sensing elements 70, extend further inwards than the first sealing parts 21 on the sides of the pair of long sides 5b and 5c.Therefore, the distance from the inner edge 21c of the first sealing element 21 to the position corresponding to the coupling section 60 between the sensing element 70 and the conductive plate 5A is shortened. Therefore, it is possible to reduce the amount of sealing element 80 applied.

[0085] Up to now, the power storage device 1 has been described according to the embodiment described above, but the present disclosure is not limited to the embodiment described above. Fig. 11A and Fig. Figure 11B shows sectional views describing a further method for sealing the area between the plate elements 50A with the second sealing section 80b. Fig. Figure 11A shows a state in which the plate elements 50 are not yet connected to each other. Fig. Figure 11B shows a state in which the plate elements 50 were coupled together. As in the Fig. As shown in Figure 11A, the second sealing section 80b is provided in each recess section 62 of the plate elements 50 before they are coupled. Subsequently, as shown in the Fig. As shown in Figure 11B, the plate elements 50 are coupled together to form the conductive plate 5A. Since the projecting section 61 and the recessed section 62 are connected to the second sealing section 80b, it is possible to seal the section between the plate elements 50.

[0086] When the plate elements 50 are coupled together, the second sealing section 80b is forced out of the interior of the recess section 62. Therefore, the second sealing section 80b leaks out at the first surface 5f and the second surface 5g of the conductive plate 5A. The conductive plate 5A is positioned on the power storage module 4 with the protruding second sealing section 80b, the second sealing section 80b being located in the position corresponding to the coupling section 60 on the metal plate 20A. Although not shown, the power storage module 4 is laminated onto the conductive plate 5A, with the second sealing section 80b also being located in the position corresponding to the coupling section 60 on the metal plate 20B. Therefore, penetration of the metal plates 20A and 20B into the gap G, e.g., due to fluctuations in the internal pressure of the power storage module 4, is prevented.

[0087] In this case as well, the second sealing section 80b is provided along the connecting section 60 between the adjacent plate elements 50A on both the side of the metal plate 20A and the side of the metal plate 20B. On both the side of the metal plate 20A and the side of the metal plate 20B, the second sealing section 80b adheres to each of the adjacent plate elements 50A and the non-contact area 20f and fills the area between each of the adjacent plate elements 50A and the non-contact area 20f. Here, the second sealing section 80b on the side of the metal plate 20A and the second sealing section 80b on the side of the metal plate 20B are continuously connected to each other.This means that the section between the adjacent plate elements 50 is completely filled with a second sealing section 80b and is continuous from the first surface 5f to the second surface 5g.

[0088] With such a configuration it is possible to further suppress the formation and progression of rust on the metal plates 20A and 20B.

[0089] In this embodiment, the first sealing element 21 overlaps, in the Z-direction, the pair of long sides 5b and 5c, which form part of the outer edge of the conductive plate 5. The first sealing element 21 also overlaps the pair of short sides 5d and 5e, which form other parts of the outer edge of the conductive plate 5. In this case, it is also possible to prevent damage to the metal plates 20A and 20B due to contact with the pair of short sides 5d and 5e of the conductive plate 5. Since the first sealing elements 21 are positioned at the locations corresponding to the coupling sections 60 between the sensing element 70 and the conductive plate 5A on the metal plates 20A and 20B, it is also unnecessary to provide the sealing elements 80 at these positions.

[0090] A power storage device comprises a power storage module, a conductive plate, and a sealing element. The power storage module has an electrode laminate and a sealing body. The sealing body has several resin sections. The metal plates at the laminate ends of the electrode laminate each have an exposed surface that is exposed by the resin section. The exposed surface has a contact area and a non-contact area. The sealing element has a first sealing section. The first sealing section is positioned along an inner edge of the resin section to be in contact with the resin section. The first sealing section adheres to the conductive plate and the non-contact area and fills a gap between the conductive plate and the non-contact area. The first sealing section seals a gap between the conductive plate and the exposed surface.

Claims

[1] Power storage device (1), with a power storage module (4); a conductive plate (5, 5A) which is intended to be laminated with the power storage module (4); and a sealing element (80) provided between the conductive plate (5, 5A) and the power storage module (4), wherein the power storage module (4) has an electrode laminate (11) with several laminated metal plates (15, 20A, 20B) and a sealing body (12) which is provided such that it surrounds a side surface of the electrode laminate (11), forms an interior space between adjacent electrodes (14, 18, 19) and seals the interior space, the several metal plates (15, 20A, 20B) have a metal plate (15) of a negative terminal electrode (18), a metal plate (15) of a positive terminal electrode (19) and metal plates (15) of several bipolar electrodes (14) which are provided between the negative terminal electrode (18) and the positive terminal electrode (19), the sealing body (12) has several resin sections (21), each of which has a frame shape and is provided at individual edge sections (15c, 20c) of the several metal plates (15, 20A, 20B) in the electrode laminate (11), the metal plates (20A, 20B) at the laminate ends of the electrode laminate (11) each have an exposed surface (20d) that is exposed by the resin section (21), the exposed surface (20d) has a contact area (20e) that is in contact with the conductive plate (5, 5A) and a non-contact area (20f) that is not in contact with the conductive plate (5, 5A), and the sealing element (80) has a first sealing section (80a) which is provided along an inner edge of the resin section (21) to be in contact with the resin section (21), adheres to the conductive plate (5, 5A) and the non-contact area (20f), fills a section between the conductive plate (5, 5A) and the non-contact area (20f) and seals a section between the conductive plate (5, 5A) and the exposed surface (20d), characterized by , that the conductive plate (5A) has several interconnected plate elements (50), and the sealing element (80) has a second sealing section (80b) which is provided along a coupling section (60) formed between the adjacent plate elements (50), adheres to each of the adjacent plate elements (50) and the non-contact area (20f), fills a section between each of the adjacent plate elements (50) and the non-contact area (20f) and seals the section between the conductive plate (5, 5A) and the exposed surface (20d). [2] Power storage device (1) according to claim 1, wherein the conductive plate (5, 5A) has a first surface (5a, 15a) and a second surface (15b) in a lamination direction of the electrode laminate (11), and the second sealing section (80b) fills a section between the adjacent plate elements (50) and is provided continuously from the first surface (5a, 15a) to the second surface (15b). [3] Power storage device (1) according to claim 1, wherein at an end section of the coupling section (60) in a lamination direction of the electrode laminate (11) a distance between the adjacent plate elements (50) becomes wide when the plate elements (50) approach the metal plate (5, 5A) at the laminate end. [4] Power storage device (1) according to any one of claims 1 to 3, wherein the sealing element (80) is a seal in liquid form. [5] Power storage device (1) according to one of claims 1 to 4, wherein the resin section (21) overlaps an outer edge of the conductive plate (5, 5A) when viewed in a lamination direction of the electrode laminate (11). [6] Power storage device (1) according to any one of claims 1 to 5, further comprising a detection element (70) coupled to an end face of the conductive plate (5, 5A), wherein the first sealing section (80a) extends from the inner edge to a position corresponding to a coupling section (60) formed between the sensing element (70) and the conductive plate (5, 5A) in the metal plate (15) at the laminate end.

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