Energy storage module

Abstract

To provide a power storage module that is easy to assemble.SOLUTION: A power storage module 1 based on the present disclosure includes a plurality of power storage cells 10, a module case 20, and a connection member 30. The plurality of power storage cells 10 each have an electrode assembly 100, a cell case 200, and an external terminal 300. The external terminal 300 is electrically connected to the electrode assembly 100, is arranged outside the cell case 200, and is located side by side with the cell case 200 in a second direction D2 orthogonal to a first direction D1. The module case 20 has a bottom surface portion 21 and a peripheral side surface portion 22. The connection member 30 is in contact with the external terminal 300 of each of the power storage cells 10 adjacent to each other, among the plurality of power storage cells 10. At least a part of the connection member 30 is embedded in the peripheral side surface portion 22.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to an energy storage module. [Background technology]

[0002] U.S. Patent Application Publication No. 2016 / 0372793 (Patent Document 1) discloses a conventional rechargeable battery module. The rechargeable battery module includes a plurality of rechargeable batteries and a connection member that electrically connects one of the plurality of rechargeable batteries. The rechargeable battery includes an electrode assembly, a case, a cover plate, a first sub-terminal, and a second sub-terminal. The cover plate seals the opening of the case. The first sub-terminal has a first portion and a second portion integrally formed with the first portion. The first portion is located at one end of the cover plate. The second portion is located on the outer surface of the case. The connection member includes a first connection member. The first connection member is joined to the outer surface of the second portion of the first sub-terminal of an adjacent rechargeable battery among the plurality of rechargeable batteries. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2016 / 0372793 Summary of the Invention [Problem to be solved by the invention]

[0004] In the energy storage module disclosed in Patent Document 1, the connection members are located to the sides of the energy storage cells. This makes it more difficult to connect the connection members to the external terminals than when the connection members are located above the energy storage cells. This makes it difficult to assemble the energy storage module.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide an electricity storage module that is easy to assemble. [Means for solving the problem]

[0006] An energy storage module according to the present disclosure includes a plurality of energy storage cells, a module case, and a connecting member. The energy storage cells are aligned in a first direction. The module case houses the plurality of energy storage cells. The connecting member electrically connects the plurality of energy storage cells to one another. Each of the plurality of energy storage cells includes an electrode assembly, a cell case, and an external terminal. The cell case houses the electrode assembly. The external terminal is electrically connected to the electrode assembly, disposed outside the cell case, and aligned with the cell case in a second direction perpendicular to the first direction. The module case has a bottom surface portion and a peripheral side surface portion. The bottom surface portion is aligned with the plurality of energy storage cells in a third direction perpendicular to both the first and second directions. The peripheral side surface portion rises from the bottom surface portion in the third direction and surrounds the plurality of energy storage cells. The connecting member contacts the external terminals of adjacent energy storage cells among the plurality of energy storage cells. At least a portion of the connecting member is embedded in the peripheral side surface portion.

[0007] According to the above configuration, since at least a part of the connection member is embedded in the peripheral side surface portion, it is easy to align the connection member with the external terminal of the energy storage cell, and therefore it is possible to provide an energy storage module that is easy to assemble. [Effects of the Invention]

[0008] According to the present disclosure, an easily assembled energy storage module is provided. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view schematically illustrating an energy storage module according to an embodiment of the present disclosure. [Figure 2] FIG. 1 is a plan view schematically illustrating an energy storage module according to an embodiment of the present disclosure. [Figure 3] 1 is a perspective view schematically illustrating an energy storage cell according to an embodiment of the present disclosure. [Figure 4] 4 is a cross-sectional view of the energy storage module of FIG. 2 as viewed in the direction of the arrows along line IV-IV. [Figure 5]5 is a cross-sectional view of the electrode body of FIG. 4 as seen in the direction of the arrow VV line. [Figure 6] FIG. 10 is a perspective view schematically showing a process of housing a plurality of energy storage cells in a module case. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present disclosure will be described with reference to the accompanying drawings, in which the same or corresponding elements are designated by the same reference numerals.

[0011] Fig. 1 is a perspective view schematically illustrating an energy storage module according to an embodiment of the present disclosure. Fig. 2 is a plan view schematically illustrating an energy storage module according to an embodiment of the present disclosure. As shown in Figs. 1 and 2, an energy storage module 1 according to an embodiment of the present disclosure includes a plurality of energy storage cells 10, a module case 20, one or more connection members 30, and one or more spacers 40.

[0012] The plurality of energy storage cells 10 are arranged in a first direction D1. Specifically, two or more energy storage cells 10 are arranged so as to be arranged in the first direction D1 of the energy storage cells 10. A spacer 40 is arranged between a pair of energy storage cells 10 adjacent to each other.

[0013] First, the details of the configuration of each of the energy storage cells 10 will be described. Fig. 3 is a perspective view schematically showing an energy storage cell according to an embodiment of the present disclosure. Fig. 4 is a cross-sectional view of the energy storage module of Fig. 2 as viewed in the direction of the arrows IV-IV.

[0014] As shown in FIGS. 3 and 4, the energy storage cell 10 includes an electrode assembly 100, a cell case 200, a pair of external terminals 300, a pair of connecting members 400, and an insulating member 500.

[0015] Fig. 5 is a cross-sectional view of the electrode assembly of Fig. 4 as viewed in the direction of the arrows VV. As shown in Fig. 5, the electrode assembly 100 includes a plurality of electrodes 110, 120 and a separator .

[0016] 5, the plurality of electrodes 110, 120 are arranged to line up in a first direction D1. The plurality of electrodes 110, 120 includes a plurality of positive electrodes 110 and a plurality of negative electrodes 120.

[0017] Each positive electrode 110 is formed in a rectangular shape that is long in the second direction D2 (a direction perpendicular to the paper surface in FIG. 5). The second direction D2 is a direction perpendicular to the first direction D1. Each positive electrode 110 has a positive electrode current collector foil 112 and positive electrode active material layers 114 provided on both sides of the positive electrode current collector foil 112. The positive electrode current collector foil 112 has a positive electrode tab 112p (see FIG. 4) on which the positive electrode active material layer 114 is not provided. The positive electrode tab 112p protrudes toward one side in the second direction D2.

[0018] Each negative electrode 120 is formed in a rectangular shape that is long in the second direction D2. Each negative electrode 120 has a negative electrode current collector foil 122 and negative electrode active material layers 124 provided on both sides of the negative electrode current collector foil 122. As shown in FIG. 4, the negative electrode current collector foil 122 has a negative electrode tab 122n (see FIG. 4) on which the negative electrode active material layer 124 is not provided. The negative electrode tab 122n protrudes toward the other side in the second direction D2.

[0019] The separator 130 provides insulation between the positive electrode 110 and the negative electrode 120. The separator 130 is made of an insulating material and has minute voids that allow ions to pass through. As shown in Figure 5, the separator 130 is formed in a zigzag shape.

[0020] The separator 130 has a rectangular shape before being folded in a zigzag shape. The separator 130 is disposed between the electrodes 110, 120 while being folded in a zigzag shape. The separator 130 has a plurality of intervening portions 132a, a plurality of upper folded portions 132b, a plurality of lower folded portions 132c, and an outermost covering portion 132d.

[0021] Each intervening portion 132a is interposed between a pair of electrodes 110, 120 adjacent to each other in the first direction D1. That is, each intervening portion 132a has a function of insulating between the positive electrode 110 and the negative electrode 120. Each intervening portion 132a is formed of a rectangular region.

[0022] Each upper folded portion 132b connects the upper end of one of the plurality of intervening portions 132a to the upper end of another of the plurality of intervening portions 132a that is adjacent to the one intervening portion 132a on one side in the first direction D1. In this embodiment, the upper folded portion 132b is disposed above the positive electrode 110.

[0023] Each lower folded portion 132c connects the lower end of one of the plurality of intervening portions 132a to the lower end of another of the plurality of intervening portions 132a that is adjacent to the one intervening portion on the other side in the first direction D1. In this embodiment, the lower folded portion 132c is disposed below the negative electrode 120. In other words, the negative electrode 120 is disposed on the lower folded portion 132c.

[0024] The outermost covering portion 132d collectively covers each of the upper folded portions 132b and each of the lower folded portions 132c. More specifically, the outermost covering portion 132d collectively covers all of the electrodes 110, 120, all of the intervening portions 132a, all of the upper folded portions 132b, and all of the lower folded portions 132c while being wound around a central axis parallel to the second direction D2. The end 132e of the outermost covering portion 132d is set in a range that does not overlap with the positive electrode active material layer 114 and the negative electrode active material layer 124 in the first direction D1. In this embodiment, the end 132e of the outermost covering portion 132d is provided below each of the electrodes 110, 120. The peripheral surfaces and bottom surfaces of the multiple electrodes 110, 120 and the separator 130 are covered with an insulating film (not shown).

[0025] As shown in Figures 3 and 4, the cell case 200 houses the electrode assembly 100. The cell case 200 houses an electrolyte (not shown). The cell case 200 is sealed. The cell case 200 has a case body 210 and a lid 220.

[0026] The case body 210 has an opening that opens upward. The case body 210 is made of a metal such as aluminum. The case body 210 has a bottom wall 212 and a peripheral wall 214. The bottom wall 212 is formed in a rectangular, flat plate shape. The peripheral wall 214 stands upright from the bottom wall 212. The peripheral wall 214 is formed in a rectangular tubular shape. The length of the peripheral wall 214 in the second direction D2 is longer than the length of the peripheral wall 214 in the first direction D1. The length of the peripheral wall 214 in the third direction D3 is longer than the length of the peripheral wall 214 in the first direction D1. The third direction D3 is a direction perpendicular to both the first direction D1 and the second direction D2.

[0027] The lid 220 closes the opening of the case body 210. The lid 220 is connected to the opening by welding or the like. The lid 220 is formed in a flat plate shape. The lid 220 is made of a metal such as aluminum. The lid 220 has a pressure release valve 222 and a sealing member 224.

[0028] Pressure release valve 222 is formed in the center of lid 220. Pressure release valve 222 is formed to rupture when the internal pressure of cell casing 200 reaches or exceeds a predetermined pressure. When pressure release valve 222 ruptures, gas within cell casing 200 is released to the outside of cell casing 200 through pressure release valve 222, thereby reducing the internal pressure of cell casing 200.

[0029] The sealing member 224 seals a liquid filling port h formed in the lid 220. The liquid filling port h is a through-hole for injecting an electrolyte into the cell case 200 during the manufacturing process of the energy storage cell 10. The liquid filling port h is sealed by the sealing member 224 after the electrolyte is injected into the case body 210 through the liquid filling port h.

[0030] Each of the pair of external terminals 300 is electrically connected to the electrode body 100 (details will be described later). Each of the pair of external terminals 300 is arranged outside the cell case 200. Each of the pair of external terminals 300 is aligned with the cell case 200 on both sides in a second direction D2 perpendicular to the first direction D1 (see FIG. 4, etc.). This allows the height of the energy storage module 1 to be reduced in the third direction D3 by joining the external terminals 300 to a connecting member 30 (described later) in the second direction D2.

[0031] A pair of external terminals 300 are fixed to the cell casing 200. One of the pair of external terminals 300 is a positive electrode external terminal, and the other is a negative electrode external terminal. Each external terminal 300 is fixed to the upper surface of the lid 220 via an upper insulating part 510, which will be described later. Each external terminal 300 is made of a metal such as aluminum.

[0032] Each of the pair of external terminals 300 has a first terminal portion 310 and a second terminal portion 320. The first terminal portion 310 is located above the cell casing 200. The first terminal portion 310 is fixed to the upper surface of the lid 220 via an upper insulating portion 510. The first terminal portion 310 is formed, for example, in the shape of a rectangular parallelepiped.

[0033] The second terminal portion 320 extends from the first terminal portion 310 along the side surface of the cell case 200. More specifically, the second terminal portion 320 extends along both side portions of the peripheral wall 214 of the case body 210 in the second direction D2.

[0034] The pair of connecting members 400 connect the plurality of electrode tabs 112p, 122n to the external terminals 300. One connecting member 400 connects the plurality of positive electrode tabs 112p to the positive electrode external terminals 300, and the other connecting member 400 connects the plurality of negative electrode tabs 122n to the negative electrode external terminals 300. Since the pair of connecting members 400 have substantially the same structure, only one of the connecting members 400 will be described below.

[0035] The connecting member 400 includes a current collecting tab 410 , a sub-tab 420 , and a connecting pin 430 .

[0036] The current collecting tab 410 has a side portion 412 and an upper portion 414. The side portion 412 is located on a side of the electrode assembly 100 in the second direction D2. The upper portion 414 is located above the electrode assembly 100. The upper portion 414 extends from the upper end of the side portion 412 toward the inside in the second direction D2.

[0037] The subtabs 420 connect the multiple positive electrode tabs 112p to the current collecting tab 410. One end 422 of the subtab 420 is connected to the multiple positive electrode tabs 112p by welding or the like, and the other end 424 of the subtab 420 is connected to the side portion 412 of the current collecting tab 410 by welding or the like.

[0038] The connecting pin 430 connects the current collecting tab 410 and the first terminal portion 310 of the external terminal 300. The connecting pin 430 connects the upper portion 414 and the first terminal portion 310 of the external terminal 300. Specifically, the lower end of the connecting pin 430 is inserted into a through hole provided in the upper portion 414 and connected to the upper portion 414 by welding or the like, and the upper end of the connecting pin 430 is inserted into a through hole provided in the first terminal portion 310 of the external terminal 300 and connected to the external terminal 300 by welding, crimping or the like.

[0039] The insulating member 500 provides insulation between the cell casing 200 and the connecting member 400. The insulating member 500 has an upper insulating portion 510, a horizontal insulating portion 515, a lower insulating portion 520, an insulating cylinder 530, and an insulating plate 540.

[0040] The upper insulating part 510 is fixed to the upper surface of the lid 220. The upper insulating part 510 is disposed between the lid 220 and the first terminal part 310 of the external terminal 300. The upper insulating part 510 is provided with an insertion hole through which the connecting pin 430 is inserted.

[0041] The lateral insulating portion 515 is disposed on the peripheral wall 214 of the case body 210. The lateral insulating portion 515 extends downward from the upper insulating portion 510. The lateral insulating portion 515 is disposed between the peripheral wall 214 of the case body 210 and the second terminal portion 320 of the external terminal 300.

[0042] Lower insulating part 520 is fixed to the lower surface of lid 220. Lower insulating part 520 is disposed between lid 220 and the upper part 414 and the lower part of connecting pin 430. Lower insulating part 520 has an insertion hole through which connecting pin 430 is inserted.

[0043] The insulating cylinder 530 is disposed between the connecting pin 430 and the lid 220. The insulating cylinder 530 is formed in a cylindrical shape and surrounds the connecting pin 430.

[0044] The insulating plate 540 is fixed to the lower surface of the upper part 414. The insulating plate 540 is disposed above the electrode assembly 100. Through holes are provided in the insulating plate 540 in a portion located below the pressure release valve 222 and a portion located below the liquid injection port h.

[0045] The insulating member 500 that insulates one of the pair of connecting members 400 (for example, the connecting member 400 electrically connected to the positive electrode tab 112p) from the cell case 200 may not have the upper insulating portion 510 and the horizontal insulating portion 515. In this case, the external terminal 300 may be in direct contact with the cell case 200, or another conductive member may be disposed between the external terminal and the cell case 200 in place of the upper insulating portion 510 and the horizontal insulating portion 515.

[0046] Next, a description will be given of the module case 20 and the connection members 30 of the energy storage module 1. Fig. 6 is a perspective view that schematically shows a process of housing a plurality of energy storage cells in the module case.

[0047] 1, 2, 4, and 6, the module case 20 houses a plurality of energy storage cells 10. The module case 20 has a bottom surface portion 21 and a peripheral side surface portion 22.

[0048] The bottom surface portion 21 is aligned with the plurality of energy storage cells 10 in the third direction D3. The bottom surface portion 21 is in contact with the plurality of energy storage cells 10. The bottom surface portion 21 has a substantially rectangular outer shape when viewed from the third direction D3.

[0049] The peripheral side surface portion 22 is formed integrally with the bottom surface portion 21. The peripheral side surface portion 22 stands upright from the bottom surface portion 21 in the third direction D3 and surrounds the plurality of energy storage cells 10.

[0050] The module case 20 is made of an insulating material and is made entirely of a resin composition.

[0051] The connection member 30 is in contact with the external terminals 300 of adjacent ones of the plurality of energy storage cells 10. Specifically, the connection member 30 is in contact with the second terminal portions 320 of the external terminals 300 of adjacent ones of the plurality of energy storage cells 10.

[0052] More specifically, the first connection member 30A is arranged on the external terminal 300 (second terminal portion 320) of a first storage cell 10A, which is one of the plurality of storage cells 10, and on the external terminal 300 (second terminal portion 320) of a second storage cell 10B, which is another one of the two or more storage cells 10 and adjacent to the first storage cell 10A. In the present embodiment, the first connection member 30A connects the external terminal 300 on the negative electrode 120 side of the first storage cell 10A and the external terminal 300 on the positive electrode 110 side of the second storage cell 10B.

[0053] The connection member 30 is conductive. Therefore, the connection member 30 electrically connects the external terminal 300 of the first energy storage cell 10A and the external terminal 300 of the second energy storage cell 10B. Consequently, the connection member 30 electrically connects the plurality of energy storage cells 10 to one another.

[0054] At least a portion of the connecting member 30 is embedded in the peripheral side surface portion 22. This can increase the rigidity of the module case 20. The connecting member 30 can be embedded in the peripheral side surface portion 22, for example, by molding the module case 20 by injection molding a resin so as to cover a portion of the connecting member 30.

[0055] The connecting member 30 has a connecting surface 31 that contacts the external terminal 300 and a buried surface 32 that is located opposite the connecting surface 31 (see FIG. 4). The connecting surface 31 and a portion 22b of the inner surface 22a of the peripheral side surface portion 22 that contacts the external terminal 300 are located on the same imaginary plane.

[0056] In this embodiment, the buried surface 32 is not exposed to the outside because its entire surface is in contact with the module case 20. However, a portion of the buried surface 32 may be exposed to the outside of the module case 20 through a hole formed in the module case 20.

[0057] The connection member 30 is made of a metal such as aluminum or an aluminum alloy. The connection member 30 may or may not be joined to the external terminal 300 (second terminal portion 320) by welding or the like.

[0058] In this embodiment, the plurality of energy storage cells 10 further includes a third energy storage cell 10C. Furthermore, the one or more connection members 30 further include a second connection member 30B that is different from the first connection member 30A.

[0059] The third storage cell 10C is located on the opposite side of the first storage cell 10A from the second storage cell 10B. The third storage cell 10C is adjacent to the first storage cell 10A. The second connection member 30B is arranged on the other external terminal 300 (second terminal portion 320) of the first storage cell 10A and on the external terminal 300 (second terminal portion 320) of the third storage cell 10C.

[0060] In this embodiment, both the first connecting member 30A and the second connecting member 30B are provided on the inner surface 22a side of the peripheral side surface portion 22. In this embodiment, all of the connecting members 30 are provided on the inner surface 22a side of the peripheral side surface portion 22.

[0061] As described above, the energy storage module 1 according to an embodiment of the present disclosure includes a plurality of energy storage cells 10, a module case 20, and a connecting member 30. The energy storage cells 10 are aligned in a first direction D1. The module case 20 houses the plurality of energy storage cells 10. The connecting member 30 electrically connects the plurality of energy storage cells 10 to one another. Each of the plurality of energy storage cells 10 includes an electrode assembly 100, a cell case 200, and an external terminal 300. The cell case 200 houses the electrode assembly 100. The external terminal 300 is electrically connected to the electrode assembly 100, is disposed outside the cell case 200, and is aligned with the cell case 200 in a second direction D2 perpendicular to the first direction D1. The module case 20 has a bottom surface portion 21 and a peripheral side surface portion 22. The bottom surface portion 21 is aligned with the multiple energy storage cells 10 in a third direction D3 that is perpendicular to both the first direction D1 and the second direction D2. The peripheral side surface portion 22 stands up from the bottom surface portion 21 in the third direction D3 and surrounds the multiple energy storage cells 10. The connection member 30 is in contact with each external terminal 300 of adjacent energy storage cells 10 among the multiple energy storage cells 10. At least a portion of the connection member 30 is embedded in the peripheral side surface portion 22.

[0062] According to the above configuration, at least a portion of the connection member 30 is embedded in the peripheral side surface portion 22, which makes it easy to align the connection member 30 with the external terminals 300 of the energy storage cells 10. As a result, it is possible to provide an energy storage module 1 that is easy to assemble.

[0063] Furthermore, the external terminals 300 are in further contact with the peripheral side surface portions 22. With this configuration, the energy storage cells 10 can be fixed to the module case 20 more firmly.

[0064] The connecting member 30 has a connecting surface 31 that contacts the external terminal 300 and a buried surface 32 that is located opposite the connecting surface 31. The connecting surface 31 and a portion 22b of the inner surface 22a of the peripheral side surface portion 22 that contacts the external terminal 300 are located on the same imaginary plane.

[0065] The above configuration makes it easier to accommodate the plurality of energy storage cells 10 in the module case 20. For example, as shown in Fig. 6, when the energy storage cells 10 are accommodated in the module case 20 from the side opposite to the bottom surface portion 21, the connection members 30 can be less likely to come into unintentional contact with the energy storage cells 10 in the third direction D3.

[0066] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims rather than the description of the above embodiments, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0067] 1 Energy storage module, 10 Energy storage cell, 10A First energy storage cell, 10B Second energy storage cell, 10C Third energy storage cell, 20 Module case, 21 Bottom surface, 22 Peripheral side surface, 30 Connection member, 30A First connection member, 30B Second connection member, 31 Connection surface, 32 Buried surface, 40 Spacer, 100 Electrode body, 110 Positive electrode, 112 Positive electrode current collector foil, 112p Positive electrode tab, 114 Positive electrode active material layer, 120 Negative electrode, 122 Negative electrode current collector foil, 122n Negative electrode tab, 124 Negative electrode active material layer, 130 Separator, 132a Interposition portion, 132b Upper folded portion, 132c Lower folded portion, 132d Outermost coating portion, 132e End, 200 Cell case, 210 Case body, 212 bottom wall, 214 peripheral wall, 220 lid, 222 pressure release valve, 224 sealing member, 300 external terminal, 310 first terminal portion, 320 second terminal portion, 400 connecting member, 410 current collecting tab, 412 side portion, 414 upper portion, 420 sub-tab, 422 one end portion, 424 other end portion, 430 connecting pin, 500 insulating member, 510 upper insulating portion, 515 lateral insulating portion, 520 insulating portion, 530 insulating tube, 540 insulating plate, h filling port.

Claims

1. A plurality of storage cells arranged in a first direction; a module case that houses the plurality of power storage cells; a connection member that electrically connects the plurality of power storage cells to each other, Each of the plurality of storage cells is An electrode body; a cell case that accommodates the electrode assembly; an external terminal electrically connected to the electrode body, disposed outside the cell casing, and aligned with the cell casing in a second direction perpendicular to the first direction; The module case includes: a bottom surface portion aligned with the plurality of storage cells in a third direction orthogonal to both the first direction and the second direction; a peripheral side surface portion that rises from the bottom surface portion in the third direction and surrounds the plurality of energy storage cells, the connection member contacts the external terminals of adjacent storage cells among the plurality of storage cells, At least a portion of the connecting member is embedded in the peripheral side surface portion, the external terminal is further in contact with the peripheral side surface portion in the second direction, the connection member has a connection surface facing the second direction and in contact with the external terminal; the connection surface and an inner surface of a portion of the peripheral side surface portion that surrounds the connection member are located on the same imaginary plane that extends perpendicular to the second direction.

2. The connecting member further has a recessed surface located opposite the connecting surface, The energy storage module according to claim 1 , wherein the connection surface is located on the same imaginary plane as a portion of the inner surface of the peripheral side surface portion that is in contact with the external terminal.

3. A storage module as described in claim 1 or claim 2, wherein the inner surface of the peripheral side portion that faces the multiple storage cells in the second direction is composed of a plane perpendicular to the second direction.

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