Energy storage cells and modules

Abstract

To facilitate a positioning of component such as a bus bar for connecting power storage cells to each other.SOLUTION: A power storage cell 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 fixed to the cell case 200. The external terminal 300 includes a first terminal portion 310 and a second terminal portion 320. The first terminal portion 310 is located above the cell case 200. The second terminal portion 320 extends from the first terminal portion 310 along the side surface of the cell case 200. The second terminal portion 320 is provided with a recess 321. The recess 321 is formed on a surface of the second terminal portion 320 opposite to the other surface thereof that faces the cell case 200.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] U.S. Patent Application Publication No. 2016 / 0372793 (Patent Document 1) discloses a conventional rechargeable battery. 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 is located on one end of the cover plate and extends adjacent to the outer surface of the case. The second sub-terminal is located on the other end of the cover plate and extends adjacent to the other outer surface of the case. [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 rechargeable battery (storage cell) disclosed in Patent Document 1, in order to reduce the height of the storage module, the external terminals (sub-terminals) of adjacent storage cells are electrically connected to each other by bus bars or the like on the side of the case. However, it is not easy to position the bus bars or the like with respect to the external terminals located on the side of the case.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a storage cell and a storage module that can easily position components such as bus bars for connecting storage cells to each other. [Means for solving the problem]

[0006] An energy storage cell according to the present disclosure includes an electrode assembly, a cell case, and an external terminal. The cell case houses the electrode assembly. The external terminal is fixed to the cell case. The external terminal has a first terminal portion and a second terminal portion. The first terminal portion is located above the cell case. The second terminal portion extends from the first terminal portion along a side surface of the cell case. The second terminal portion has a recess. The recess is formed on the surface of the second terminal portion opposite the surface facing the cell case.

[0007] An energy storage module according to one embodiment of the present disclosure includes two or more of the above-described energy storage cells, a band, and a bus bar. The two or more energy storage cells are arranged side by side in the horizontal direction. The band surrounds the two or more energy storage cells. The bus bar is arranged on a recess of a first energy storage cell, which is one of the two or more energy storage cells, and on a recess of a second energy storage cell, which is another of the two or more energy storage cells and adjacent to the first energy storage cell. The bus bar is provided on a surface of the band facing the energy storage cells. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to easily position components such as bus bars for connecting energy storage cells to each other. [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. 10 is another perspective view schematically illustrating the 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. 1 as viewed from 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 from the direction of the arrow VV line. [Figure 6] FIG. 10 is a perspective view schematically illustrating a process of attaching bands to a plurality of storage cells. 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 another perspective 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 two or more energy storage cells 10, a band 20, and one or more bus bars 30.

[0012] The two or more storage cells 10 are arranged side by side in the horizontal direction. Specifically, the two or more storage cells 10 are arranged side by side in the thickness direction of the storage cells 10. A spacer (not shown) may be arranged between a pair of adjacent storage cells 10.

[0013] First, the details of the configuration of the energy storage cell 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. 1 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, seen from 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 side by side in one direction (the left-right direction in FIG. 5). 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 width direction (a direction perpendicular to both one direction and the up-down direction). 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 width direction (a direction perpendicular to the paper surface in FIG. 5).

[0018] Each negative electrode 120 is formed in a rectangular shape that is long in the width direction. Each negative electrode 120 has a negative electrode current collector foil 122 and a negative electrode active material layer 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 width direction.

[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 one direction. In other words, each intervening portion 132a has the 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 one direction. 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 one direction. 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 width direction. 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 one direction. 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 square cylindrical shape. The length of the peripheral wall 214 in the width direction is longer than the length of the peripheral wall 214 in the thickness direction. The length of the peripheral wall 214 in the height direction is longer than the length of the peripheral wall 214 in the thickness direction.

[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] 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.

[0031] 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.

[0032] The second terminal portion 320 extends from the first terminal portion 310 along the side surface of the cell casing 200. More specifically, the second terminal portion 320 extends along the peripheral wall 214 of the case body 210 in the thickness direction.

[0033] The second terminal portion 320 has a recess 321. The recess 321 is formed on the surface of the second terminal portion 320 opposite the surface facing the cell case 200 (case main body 210). When viewed in the direction in which the second terminal portion 320 and the cell case 200 (case main body 210) are aligned (i.e., the width direction), the recess 321 extends from one edge 322 to the other edge 323 in the lateral direction of the second terminal portion 320 (see FIG. 3).

[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 width direction. 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 width direction.

[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 band 20 and the bus bar 30 of the energy storage module 1. Fig. 6 is a perspective view that schematically shows a process of attaching the band to a plurality of energy storage cells.

[0047] 1, 2, 4, and 6, the band 20 surrounds two or more storage cells 10. The band 20 extends in a circular shape along a horizontal direction perpendicular to the vertical direction. The band 20 has a belt-like outer shape.

[0048] The band 20 is configured to be stretchable. The band 20 surrounds the energy storage cells 10 in a stretched state. When the band 20 surrounds the energy storage cells 10, it constrains two or more energy storage cells 10 by its tendency to contract. The band 20 is configured to be able to stretch further from the state in which it surrounds the energy storage cells 10. The material constituting the band 20 is not particularly limited. The band 20 may be made of an elastic material such as silicone rubber.

[0049] In this embodiment, the band 20 is composed of a single band member formed in a ring shape. However, the band 20 may also be formed in a ring shape by connecting both ends of a single strip-shaped band member to each other. In other words, the band 20 may have a connection portion formed by connecting the both ends to each other.

[0050] The band 20 may be composed of two or more strip-shaped band members. In this case, the ends of adjacent band members may be connected to each other, thereby forming the band 20 in a ring shape. In other words, the band 20 may have two or more connection parts formed by connecting the ends of two or more band members to each other.

[0051] At the connection portion, the band members constituting the band 20 may be separable from each other. The length of the band 20 in the annular extension direction may be adjustable at the connection portion. This allows the design of the band 20 to be easily changed when the shape of the energy storage cells 10 or the number of energy storage cells 10 is changed. The connection portion may have a structure similar to a belt buckle so that the length of the band 20 can be changed.

[0052] The bus bar 30 (first bus bar 30A) is arranged on a recess 321 of a first storage cell 10A, which is one of the two or more storage cells 10, and on a recess 321 of a second storage cell 10B, which is another one of the two or more storage cells 10 and is adjacent to the first storage cell 10A.

[0053] The bus bar 30 is electrically conductive. Therefore, the bus bar 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. The bus bar 30 is made of a metal such as aluminum or an aluminum alloy. The bus bar 30 may or may not be joined to these external terminals 300 by welding or the like.

[0054] In this embodiment, the two or more storage cells 10 further include a third storage cell 10C. Moreover, the one or more bus bars 30 further include a second bus bar 30B different from the first bus bar 30A.

[0055] The third storage cell 10C is located on the opposite side of the first storage cell 10A from the second storage cell 10B side. The third storage cell 10C is adjacent to the first storage cell 10A. The second bus bar 30B is arranged on another recess 321 of the first storage cell 10A and on the recess 321 of the third storage cell 10C.

[0056] The bus bar 30 is provided on a surface of the band 20 facing the energy storage cells 10. A portion of the bus bar 30 is embedded in the band 20.

[0057] In this embodiment, both the first bus bar 30A and the second bus bar 30B are provided on the surface of the band 20 facing the energy storage cells 10. More specifically, all of the bus bars 30 located on the inner periphery of the band 20 are provided on the surface of the band 20 facing the energy storage cells 10. These bus bars 30 are fixed on the surface of the band 20. On the surface of the band 20, these bus bars 30 are spaced apart from each other.

[0058] As described above, in the energy storage cell 10 according to one embodiment of the present disclosure, the second terminal portion 320 has the recessed portion 321. The recessed portion 321 is formed on the surface of the second terminal portion 320 opposite to the surface facing the cell case 200.

[0059] According to the above configuration, by placing the bus bar 30 on the recess 321, it is easy to position the bus bar 30 relative to the external terminal 300. Therefore, it is easy to position the bus bar or other member for connecting the energy storage cells 10 to each other.

[0060] The recess 321 extends from one edge 322 to the other edge 323 in the lateral direction of the second terminal 320 when viewed from the direction in which the second terminal 320 and the cell casing 200 are aligned.

[0061] According to the above configuration, the bus bar 30 can slide on the recess 321 in the thickness direction of the cell case 200. This makes it easy to position the bus bar 30 and other components relative to the second terminal portion 320 in the vertical direction, and to adjust the position of the bus bar 30 and other components relative to the second terminal portion 320 in the horizontal direction. This further improves the workability of connecting the energy storage cells 10 to each other.

[0062] Moreover, the energy storage module 1 according to an embodiment of the present disclosure includes two or more energy storage cells 10, a band 20, and a bus bar 30. The two or more energy storage cells 10 are arranged side by side in the horizontal direction. The band 20 surrounds the two or more energy storage cells 10. The bus bar 30 is arranged on a recess 321 of a first energy storage cell 10A, which is one of the two or more energy storage cells 10, and on a recess 321 of a second energy storage cell 10B, which is another one of the two or more energy storage cells 10 and adjacent to the first energy storage cell 10A. The bus bar 30 is provided on a surface of the band 20 facing the energy storage cells 10.

[0063] According to the above configuration, the height of the energy storage module 1 can be reduced compared to when the external terminals 300 are connected to each other by bus bars above the external terminals 300. Furthermore, by attaching the bands 20 to the plurality of energy storage cells 10 from above and below (see FIG. 6), the bus bars 30 can be easily disposed in each recess 321. This further improves the workability of connecting the energy storage cells 10 to each other.

[0064] Moreover, the band 20 is configured to be stretchable. With this configuration, the band 20's tendency to shrink allows it to restrain a plurality of energy storage cells 10. Furthermore, by restraining the energy storage cells 10 with the band 20, the bus bar 30 can be fixed on the recess 321 before welding the bus bar 30 to the external terminal 300, or without welding. Furthermore, by stretching the band 20, the bus bar 30 can be easily removed from above the recess 321. Therefore, the workability of connecting the energy storage cells 10 can be further improved.

[0065] 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 above description of the embodiments, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0066] 1 Energy storage module, 10 Energy storage cell, 10A First energy storage cell, 10B Second energy storage cell, 10C Third energy storage cell, 100 Electrode body, 110 (Positive electrode) electrode, 112 Positive electrode current collector foil, 112p Electrode tab (Positive electrode tab), 114 Positive electrode active material layer, 120 (Negative electrode) electrode, 122 Negative electrode current collector foil, 122n Electrode tab (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, 321 recess, 322 one end edge, 323 other end edge, 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, 20 band, 30 bus bar, 30A first bus bar, 30B second bus bar.

Claims

1. An electrode body; a cell case that accommodates the electrode assembly; an external terminal fixed to the cell casing; the external terminal has a first terminal portion located above the cell case and a second terminal portion extending from the first terminal portion along a side surface of the cell case, The second terminal portion has a recess that is a bus bar connection portion formed on a surface of the second terminal portion opposite a surface facing the cell case.

2. The energy storage cell according to claim 1 , wherein the recess extends from one lateral edge to the other lateral edge of the second terminal portion when viewed in a direction in which the second terminal portion and the cell casing are aligned.

3. Two or more of the storage cells according to claim 1 or 2 arranged side by side in a horizontal direction; a band surrounding two or more of the storage cells; a bus bar disposed on the recess of a first storage cell that is one of the two or more storage cells and on the recess of a second storage cell that is another one of the two or more storage cells and adjacent to the first storage cell, The bus bar is provided on a surface of the band facing the storage cells.

4. The energy storage module according to claim 3 , wherein the band is configured to be stretchable.

Images