Energy storage cell

Abstract

To provide a power storage cell capable of reducing a housing space of a collector tub.SOLUTION: A power storage cell comprises: an electrode body 100; and a cell case 200. The electrode body includes: a plurality of electrodes; and a separator. Each electrode includes: a collector foil; and an active material layer. The collector foil includes a collector tub. The plurality of electrodes includes: a first tub group P1 formed by the plurality of collector tubs arranged so as to be arranged toward the other side from an end part on one side in a second direction; and a second tub group P2 formed by the plurality of collector tubs arranged so as to be arranged toward the one side from the end part of the other side in a second direction. Each collector tub 112p in the first tub group P1 is folded toward the other side from the one side in one direction, and each collector tub 112p in the second tub group P2 is folded toward the one side from the other side in the one direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] International Publication No. 2009 / 031442 discloses a stacked battery comprising a stack electrode assembly, a current collector lead plate, and a battery can. The stack electrode assembly has a current collector tab group formed by bundling a plurality of current collector tabs. The current collector tab group is welded to the underside of the current collector lead plate. The current collector lead plate is welded to the lower end of an external terminal provided on the battery can. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2009 / 031442 Summary of the Invention [Problem to be solved by the invention]

[0004] In the stacked cell described in WO 2009 / 031442, multiple current collecting tabs must be bundled together, which makes each current collecting tab long, and therefore requires a large space inside the battery can to accommodate the group of current collecting tabs formed by bundling multiple current collecting tabs together.

[0005] An object of the present disclosure is to provide a storage cell that can reduce the space required to accommodate current collecting tabs. [Means for solving the problem]

[0006] An energy storage cell according to one aspect of the present disclosure includes an electrode assembly and a cell case that houses the electrode assembly, the electrode assembly having a plurality of electrodes arranged to be aligned in one direction and a separator that insulates each of the plurality of electrodes, each of the plurality of electrodes having a current collecting foil and an active material layer provided on the current collecting foil, the current collecting foil having no active material layer and a current collecting tab that protrudes in a first direction perpendicular to the one direction from a region of the current collecting foil where the active material layer is provided, and the plurality of electrodes are arranged in both the one direction and the first direction. The current collector tabs include a first tab group consisting of a plurality of the current collector tabs arranged in a row from an end on one side in a second direction that is orthogonal to the first direction toward the other side in the second direction, and a second tab group consisting of a plurality of the current collector tabs arranged in a row from an end on the other side in the second direction toward one side in the second direction, wherein each current collector tab in the first tab group is bent from one side to the other side in the first direction, and each current collector tab in the second tab group is bent from the other side to one side in the first direction. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a storage cell that can reduce the space required to accommodate current collecting tabs. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view schematically illustrating a storage cell according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view of the storage cell shown in FIG. [Figure 3] FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 10 is a plan view showing a modified example of the electrode body. [Figure 6] FIG. 10 is a plan view showing a modified example of the electrode body. [Figure 7] FIG. 10 is a cross-sectional view showing a modified example of the storage cell. DETAILED DESCRIPTION OF THE INVENTION

[0009] 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.

[0010] Fig. 1 is a perspective view schematically illustrating a storage cell according to an embodiment of the present disclosure, and Fig. 2 is a cross-sectional view of the storage cell shown in Fig. 1.

[0011] As shown in FIGS. 1 and 2, the energy storage cell 1 includes an electrode assembly 100, a cell case 200, an electrolyte (not shown), a pair of external terminals 300, a pair of connecting members 400, and an insulating member 500.

[0012] Fig. 3 is a plan view of the electrode assembly. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3. As shown in Fig. 3 and Fig. 4, the electrode assembly 100 includes a plurality of electrodes 110, 120 and a separator 130.

[0013] 4, the plurality of electrodes 110, 120 are arranged side by side in one direction (the left-right direction in FIG. 4). The plurality of electrodes 110, 120 includes a plurality of positive electrodes 110 and a plurality of negative electrodes 120.

[0014] Each positive electrode 110 is formed in a rectangular shape that is long in the width direction (a direction perpendicular to both the one direction and the up-down direction). As shown in FIG. 4, 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. As shown in FIGS. 2 and 4, the positive electrode current collector foil 112 has a positive electrode tab (current collector tab) 112p on which the positive electrode active material layer 114 is not provided. The positive electrode tab 112p protrudes from a region of the positive electrode current collector foil 112 where the positive electrode active material layer 114 is provided toward one side (the upper side in this embodiment) in a first direction (the up-down direction in FIG. 4) perpendicular to the one direction.

[0015] As shown in FIGS. 2 and 3, the plurality of positive electrodes 110 includes a first tab group P1 and a second tab group P2.

[0016] The first tab group P1 is made up of a plurality of positive electrode tabs 112p arranged side by side from an end on one side (the left side in FIG. 3) in a second direction orthogonal to both the one direction and the first direction toward the other side in the second direction (the right side in FIG. 3). For example, the number of the positive electrode tabs 112p in the first tab group P1 is set to half of the total number of positive electrode tabs 112p. Each positive electrode tab 112p in the first tab group P1 is bent from one side toward the other side in the one direction (the upper side in FIG. 3, the right side in FIG. 4). Each positive electrode tab 112p in the first tab group P1 is bent in a state where a portion of the positive electrode tab 112p overlaps with the positive electrode tab 112p adjacent to the positive electrode tab 112p. Specifically, the positive electrode tabs 112p in the first tab group P1 are arranged such that the positive electrode tab 112p adjacent to the outer side of one positive electrode tab 112p in the second direction overlaps above the one positive electrode tab 112p. The positive electrode tabs 112p in the first tab group P1 have the same length in the second direction. The positive electrode tabs 112p in the first tab group P1 have the same length in one direction.

[0017] The second tab group P2 is composed of a plurality of positive electrode tabs 112p arranged in a line from an end on the other side in the second direction toward one side in the second direction. Each positive electrode tab 112p in the second tab group P2 is bent from the other side in one direction toward one side (the lower side in FIG. 3). Each positive electrode tab 112p in the second tab group P2 is bent in a state in which a portion of the positive electrode tab 112p overlaps with the positive electrode tab 112p adjacent to the positive electrode tab 112p. Specifically, the plurality of positive electrode tabs 112p in the second tab group P2 are arranged such that, with respect to a given positive electrode tab 112p, the positive electrode tab 112p adjacent to the outer side of the given positive electrode tab 112p in the second direction overlaps above the given positive electrode tab 112p. The lengths of the positive electrode tabs 112p in the second tab group P2 in the second direction are the same. The positive electrode tabs 112p in the second tab group P2 have the same length in one direction.

[0018] Each negative electrode 120 is formed in a rectangular shape that is long in the width direction. As shown in Fig. 4, 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. 2, the negative electrode current collector foil 122 has a negative electrode tab (current collector tab) 122n on which the negative electrode active material layer 124 is not provided. The negative electrode tab 122n protrudes from a region of the negative electrode current collector foil 122 where the negative electrode active material layer 124 is provided toward the other side in the first direction (the lower side in this embodiment).

[0019] 2, the plurality of negative electrodes 120 have a first tab group N1 and a second tab group N2. The configuration of the first tab group N1 is the same as the configuration of the first tab group P1 in the positive electrode, and the configuration of the second tab group N2 is the same as the configuration of the second tab group P2 in the positive electrode. Therefore, a description of the first tab group N1 and the second tab group N2 will be omitted.

[0020] 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.

[0021] 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.

[0022] The case body 210 has an opening 210a (see FIG. 2) that opens in a direction in which each positive electrode tab 112p protrudes. In this embodiment, the opening 210a opens upward. The case body 210 is made of a metal such as aluminum. As shown in FIG. 2, 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 upper end of the peripheral wall 214 forms the opening 210a. 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.

[0023] The lid 220 closes the opening 210a of the case body 210. The lid 220 is connected to the opening 210a 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.

[0024] 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.

[0025] 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 1. 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.

[0026] A pair of external terminals 300 are fixed on the cell case 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. Each external terminal 300 is formed, for example, in the shape of a rectangular parallelepiped. A bus bar (not shown) is connected to each external terminal 300 by welding or the like.

[0027] The pair of connecting members 400 connect the multiple current collecting tabs 112p, 122n to the external terminal 300. The pair of connecting members 400 has a positive electrode connecting portion 410 that connects the multiple positive electrode tabs 112p to the positive electrode external terminal 300, and a negative electrode connecting portion 420 that connects the multiple negative electrode tabs 122n to the negative electrode external terminal 300.

[0028] The positive electrode connecting portion 410 has a positive electrode current collecting plate 412 , a positive electrode connecting pin 414 , and a positive electrode intermediate member 416 .

[0029] Positive electrode current collector 412 is connected to a plurality of positive electrode tabs 112p by welding, etc. Positive electrode current collector 412 is formed in the shape of a flat plate.

[0030] The positive electrode connecting pin 414 is connected to the positive electrode external terminal 300. The positive electrode connecting pin 414 is inserted into a through-hole provided in the lid 220 and connected to the positive electrode external terminal 300 by welding, crimping, or the like.

[0031] The positive electrode intermediate member 416 connects the positive electrode current collector plate 412 and the positive electrode connecting pin 414. The lower surface of the positive electrode intermediate member 416 is connected to the upper surface of the positive electrode current collector plate 412, and the upper surface of the positive electrode intermediate member 416 is connected to the lower end of the positive electrode connecting pin 414.

[0032] The negative electrode connecting portion 420 has a negative electrode current collecting plate 422 , a negative electrode connecting pin 424 , and a negative electrode intermediate member 426 .

[0033] The negative electrode current collector 422 is connected to the plurality of negative electrode tabs 122n by welding, etc. The negative electrode current collector 422 is formed in a flat plate shape.

[0034] The negative electrode connecting pin 424 is connected to the negative electrode external terminal 300. The negative electrode connecting pin 424 is inserted into a through-hole provided in the lid 220 and connected to the negative electrode external terminal 300 by welding, crimping, or the like.

[0035] The negative electrode intermediate member 426 connects the negative electrode current collector plate 422 and the negative electrode connecting pin 424. The lower end of the negative electrode intermediate member 426 is connected to the end of the negative electrode current collector plate 422. The upper surface of the negative electrode intermediate member 426 is connected to the lower end of the negative electrode connecting pin 424.

[0036] 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 lower insulating portion 520, an insulator 530, and an insulating plate 540.

[0037] 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 external terminal 300. The upper insulating part 510 is provided with insertion holes through which the connecting pins 414, 424 are inserted.

[0038] The lower insulating part 520 is fixed to the lower surface of the lid 220. The lower insulating part 520 is disposed between the lid 220 and the upper surfaces of the intermediate members 416, 426. The lower insulating part 520 is provided with insertion holes through which the connecting pins 414, 424 are inserted.

[0039] The insulator 530 is disposed between the connecting pins 414, 424 and the lid 220. The insulator 530 is formed in a cylindrical shape and surrounds the connecting pins 414, 424.

[0040] As described above, in the storage cell 1 of this embodiment, the multiple current collecting tabs 112p, 122n are arranged side by side in the second direction, and each current collecting tab 112p, 122n in the first tab group P1, N1 is bent from one side to the other side in one direction, and each current collecting tab 112p, 122n in the second tab group P2, N2 is bent from the other side to one side in one direction, thereby reducing the storage space for the current collecting tabs 112p, 122n.

[0041] 5, the length in one direction of each positive electrode tab 112p in the first tab group P1 may gradually decrease from one end to the other end in the second direction. Similarly, the length in one direction of each positive electrode tab 112p in the second tab group P2 may gradually decrease from the other end to one end in the second direction. In this case, the length in one direction of the positive electrode tab 112p arranged outermost in the second direction may be set to be the same as the thickness of the electrode assembly 100 in one direction.

[0042] Furthermore, as shown in FIG. 6, the plurality of positive electrode tabs 112p in the first tab group P1 and the plurality of positive electrode tabs 112p in the second tab group P2 may be arranged such that, with respect to a given positive electrode tab 112p, the positive electrode tab 112p adjacent to the inside of the given positive electrode tab 112p in the second direction overlaps above the given positive electrode tab 112p.

[0043] 7, the case body 210 may be formed in a cylindrical shape (e.g., a rectangular cylindrical shape), and the lid 220 may have a first lid portion 220a that closes one opening 210a of the case body 210 and a second lid portion 220b that closes the other opening 210b of the case body 210. In this case, the connecting member 400 may be omitted. That is, the multiple positive electrode tabs 112p may be directly connected to the first lid portion 220a by welding or the like, and the multiple negative electrode tabs 122n may be directly connected to the second lid portion 220b by welding or the like. In this case, the insulating member 500 is provided between the case body 210 and each of the lid portions 220a, 220b.

[0044] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0045] [Aspect 1] An electrode body; a cell case that houses the electrode assembly, The electrode body is A plurality of electrodes arranged in one direction; a separator for insulating each of the plurality of electrodes, Each of the plurality of electrodes A current collecting foil; an active material layer provided on the current collecting foil, the current collecting foil has a current collecting tab that is not provided with the active material layer and that protrudes in a first direction perpendicular to the one direction from a region of the current collecting foil where the active material layer is provided, The plurality of electrodes a first tab group consisting of a plurality of the current collecting tabs arranged side by side from an end on one side in a second direction perpendicular to both the one direction and the first direction to an end on the other side in the second direction; a second tab group consisting of a plurality of the current collecting tabs arranged in a line from an end on the other side in the second direction toward one side in the second direction, Each current collecting tab in the first tab group is bent from one side to the other side in the one direction, the current collecting tabs in the second tab group are bent from the other side to the one side in the one direction.

[0046] In this energy storage cell, the multiple current collecting tabs are arranged in a line in the second direction, and each current collecting tab in the first tab group is bent from one side to the other side in one direction, and each current collecting tab in the second tab group is bent from the other side to one side in one direction, thereby reducing the storage space for the current collecting tabs.

[0047] [Aspect 2] Each current collecting tab in the first tab group is bent in a state where a part of the current collecting tab overlaps with a current collecting tab adjacent to the current collecting tab, 2. The energy storage cell of aspect 1, wherein each current collecting tab in the second tab group is bent in a state where a portion of the current collecting tab overlaps with a current collecting tab adjacent to the current collecting tab.

[0048] In this embodiment, each current collecting tab in the first tab group and the second tab group is folded while overlapping with the adjacent current collecting tab, thereby reducing the dimension of the cell case in the second direction, and further, each electrode is electrically connected to each other, thereby improving reliability.

[0049] [Aspect 3] The lengths of the current collecting tabs in the first tab group in the second direction are the same, 2. The energy storage cell of aspect 1, wherein the current collecting tabs in the second tab group have the same length in the second direction.

[0050] [Aspect 4] The lengths of the current collecting tabs in the first tab group in the one direction are the same, 2. The energy storage cell of claim 1, wherein the current collecting tabs in the second tab group have the same length in the one direction.

[0051] [Aspect 5] a length in the one direction of each current collecting tab in the first tab group gradually decreases from the end on the one side toward the end on the other side in the second direction, The energy storage cell of aspect 1, wherein the length in the one direction of each of the current collecting tabs in the second tab group gradually decreases from the end on the other side toward the end on the one side in the second direction.

[0052] 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]

[0053] 1 storage cell, 100 electrode body, 110 positive electrode, 112 positive electrode current collector foil, 112p positive electrode tab (current collector tab), 114 positive electrode active material layer, 120 negative electrode, 122 negative electrode current collector foil, 122n negative electrode tab (current collector tab), 130 separator, 200 cell case, 210 case body, 220 lid, 220a first lid portion, 220b second lid portion, 300 external terminal, 400 connecting member, 412 positive electrode current collector plate, 414 positive electrode connecting pin, 416 positive electrode intermediate member, 420 negative electrode connecting portion, 422 negative electrode current collector plate, 424 negative electrode connecting pin, 426 negative electrode intermediate member, 500 insulating member, 510 upper insulating portion, 520 lower insulating portion, 530 insulator, N1 First tab group, N2 second tab group, P1 first tab group, P2 second tab group.

Claims

1. An electrode body; a cell case that houses the electrode assembly, The electrode body is A plurality of electrodes arranged in one direction; a separator for insulating each of the plurality of electrodes, Each of the plurality of electrodes A current collecting foil; an active material layer provided on the current collecting foil, the current collecting foil has a current collecting tab that is not provided with the active material layer and that protrudes in a first direction perpendicular to the one direction from a region of the current collecting foil where the active material layer is provided, The plurality of electrodes a first tab group consisting of a plurality of the current collecting tabs arranged side by side from an end on one side in a second direction perpendicular to both the one direction and the first direction toward the other side in the second direction; a second tab group consisting of a plurality of the current collecting tabs arranged side by side from the other end in the second direction toward the one side in the second direction, Each current collecting tab in the first tab group is bent from one side to the other side in the one direction, a power storage cell, wherein each current collecting tab in the second tab group is bent from the other side to the one side in the one direction.

2. Each current collecting tab in the first tab group is bent in a state where a portion of the current collecting tab overlaps with a current collecting tab adjacent to the current collecting tab, The energy storage cell according to claim 1 , wherein each current collecting tab in the second tab group is bent in a state where a portion of the current collecting tab overlaps with a current collecting tab adjacent to the current collecting tab.

3. The lengths of the current collecting tabs in the first tab group in the second direction are the same, The energy storage cell according to claim 1 , wherein the lengths of the current collecting tabs in the second tab group in the second direction are the same.

4. The lengths of the current collecting tabs in the first tab group in the one direction are the same, The energy storage cell according to claim 1 , wherein the lengths of the current collecting tabs in the second tab group in the one direction are the same.

5. a length in the one direction of each current collecting tab in the first tab group gradually decreases from the end on the one side toward the end on the other side in the second direction, The energy storage cell according to claim 1 , wherein the length in the one direction of each of the current collecting tabs in the second tab group gradually decreases from the end on the other side in the second direction toward the end on the one side.

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