Power storage cell

Abstract

To provide a power storage cell capable of suppressing the separation of an overlapping part between current collecting terminals.SOLUTION: A power storage cell 1 includes a pair of cell units 101 and 102, an intermediate member 500, and a cell case. Each cell unit includes at least one electrode body 110, a laminate exterior body 160, and a current collecting terminal 140. The pair of cell units are arranged in an orthogonal direction. The current collecting terminal of one cell unit 101 and the current collecting terminal of the other cell unit 102 include an overlap part where the current collecting terminals are overlapped with each other. The intermediate member 500 includes a pair of arm parts 510 disposed at positions of having the overlap part therebetween in a lamination direction and extending in the orthogonal direction. A length L1 of each arm part 510 in the orthogonal direction is 90% or more of a distance L2 between the opposing surface of one cell unit and the opposing surface of the other cell unit.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] For example, Japanese Patent Application Laid-Open Publication No. 2022-50804 discloses a secondary battery including a plurality of interconnected electrode bodies and an exterior housing that houses the plurality of electrode bodies. The exterior housing is formed in a rectangular parallelepiped shape. Each electrode body has a positive electrode tab and a negative electrode tab that protrude outward in a direction parallel to the longitudinal direction of the exterior housing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-50804 Summary of the Invention [Problem to be solved by the invention]

[0004] In the secondary battery described in Patent Publication No. 2022-50804, if the electrode body is displaced relative to the outer casing due to vibration or the like, stress will be generated at the connection portion of the tabs that are connected to each other, and there is a concern that the connection portion will peel off.

[0005] An object of the present disclosure is to provide an energy storage cell that can suppress peeling at the overlapping portions of the current collecting terminals. [Means for solving the problem]

[0006] A storage cell according to one aspect of the present disclosure includes a pair of cell units connected to each other, an intermediate member disposed between the pair of cell units, and a cell case accommodating the pair of cell units and the intermediate member, wherein each of the cell units has at least one electrode body, a laminated exterior body accommodating the at least one electrode body, and a current collecting terminal connected to the at least one electrode body and protruding from the laminated exterior body in an orthogonal direction perpendicular to the stacking direction of the electrode bodies, the pair of cell units being arranged side by side in the orthogonal direction, and the current collecting terminal of one cell unit of the pair of cell units being protruding from the laminated exterior body in an orthogonal direction perpendicular to the stacking direction of the electrode bodies, the intermediate member is connected to the collector terminal of the other cell unit of the one cell unit, the collector terminal of the one cell unit and the collector terminal of the other cell unit include an overlapping portion where they overlap each other, the laminated outer casing of the one cell unit and the laminated outer casing of the other cell unit include opposing surfaces that face each other in the orthogonal direction, the intermediate member is positioned to sandwich the overlapping portion in the stacking direction, and has a pair of arms extending in the orthogonal direction, and the length of each arm in the orthogonal direction is 90% or more of the distance between the opposing surfaces of the one cell unit and the opposing surfaces of the other cell unit. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide an energy storage cell that can suppress peeling at the overlapping portions of the current collecting terminals. [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 an exploded perspective view of the storage cell shown in FIG. [Figure 3] FIG. 2 is an exploded perspective view of the first cell unit. [Figure 4] FIG. 2 is a front view of the storage cell. [Figure 5] FIG. 5 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 2 is an enlarged view of the laminate exterior body and the vicinity of the arm portion. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. [Figure 8] FIG. 2 is a perspective view schematically showing the vicinity of an intermediate member. [Figure 9] FIG. 10 is a cross-sectional view schematically showing a modified example of the intermediate member. 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 showing a storage cell according to an embodiment of the present disclosure. Fig. 2 is an exploded perspective view of the storage cell shown in Fig. 1. Fig. 3 is an exploded perspective view of a first cell unit. Fig. 4 is a front view of the storage cell. Fig. 5 is a cross-sectional view taken along line VV in Fig. 4. Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 4. This storage cell 1 is mounted, for example, on the bottom of a vehicle.

[0011] 1 to 6, the energy storage cell 1 includes a plurality of cell units 100, a covering sheet 200 (see FIGS. 5 to 7), a cell case 300, an external terminal 400, and an intermediate member 500. Note that the covering sheet 200 is not shown in FIG. 2.

[0012] The multiple cell units 100 include a first cell unit 101, a second cell unit 102, a third cell unit 103, and a fourth cell unit 104. In this embodiment, the multiple cell units 100 include eight cell units 100. However, the number of cell units 100 is not limited to eight. Each cell unit 100 may be, for example, a lithium-ion battery. Each cell unit 100 may be formed of a so-called all-solid-state battery that includes a solid electrolyte.

[0013] The first cell unit 101 is connected to the second cell unit 102. The third cell unit 103 is connected to the fourth cell unit 104. The first cell unit 101 and the third cell unit 103 are adjacent to each other in a second direction perpendicular to both the first direction in which the first cell unit 101 and the second cell unit 102 are aligned and the vertical direction. The second cell unit 102 and the fourth cell unit 104 are adjacent to each other in the second direction. Each cell unit 100 has a shape that is longer in the first direction than in the second direction and that extends longer in the first direction than in the vertical direction. Each cell unit 100 has a shape that extends longer in the vertical direction than in the second direction. The first cell unit 101 and the third cell unit 103 have substantially the same structure. The second cell unit 102 and the fourth cell unit 104 have substantially the same structure.

[0014] Figure 3 is an exploded perspective view of the first cell unit 101. The first cell unit 101 has at least one electrode assembly 110, a spacer 120, a terminal member 130, a current collecting terminal 140, a cover 150, and a laminated exterior body 160. Note that in Figure 2, a portion of the laminated exterior body 160 of the third cell unit 103 and a portion of the laminated exterior body 160 of the fourth cell unit 104 are not shown.

[0015] At least one electrode body 110 includes two electrode bodies 110. However, the number of electrode bodies 110 is not limited to two. Each electrode body 110 is configured as a wound body in which a positive electrode sheet and a negative electrode sheet are wound with a separator interposed therebetween. However, each electrode body 110 may be configured as a laminate in which a positive electrode sheet and a negative electrode sheet are stacked with a separator interposed therebetween. The two electrode bodies 110 are adjacent to each other in the stacking direction in which the positive electrode sheet and the negative electrode sheet are stacked on top of each other. Each electrode body 110 is formed in a shape that is elongated in an orthogonal direction that is orthogonal to both the stacking direction and the up-down direction. The stacking direction (thickness direction) corresponds to the second direction, and the orthogonal direction corresponds to the first direction.

[0016] Each electrode body 110 has a coated portion 112 and an electrode tab 114. The coated portion 112 is a region of the electrode foil on the positive electrode sheet or negative electrode sheet where an active material layer is provided. The electrode tab 114 is a region of the electrode foil on the positive electrode sheet or negative electrode sheet where an active material layer is not provided, i.e., an uncoated portion where the electrode foil is exposed. The electrode tab 114 is formed outside the coated portion 112 in the orthogonal direction.

[0017] The spacer 120 is disposed between a pair of adjacent electrode tabs 114. The spacer 120 is made of an insulating material (synthetic resin, etc.). As shown in Figures 3 and 5, the spacer 120 has a shape in which the dimension in the stacking direction gradually increases as it moves away from the coated section 112 in the perpendicular direction.

[0018] The terminal members 130 are connected to the outer surfaces of the spacers 120 in the orthogonal direction. The terminal members 130 are made of a conductive material (metal such as copper or aluminum). As shown in Fig. 5, the terminal members 130 are connected to a pair of electrode tabs 114 adjacent to each other in the stacking direction.

[0019] The current collecting terminal 140 is connected to the terminal member 130. The current collecting terminal 140, which is electrically connected to the positive electrode tab 114 via the terminal member 130, is made of, for example, aluminum. The current collecting terminal 140, which is electrically connected to the negative electrode tab 114 via the terminal member 130, is made of, for example, copper. The current collecting terminal 140 has a connecting portion 142 and a protruding portion 144.

[0020] The connection portion 142 is connected to the outer surface of the terminal member 130 in the orthogonal direction by welding, etc. The connection portion 142 is formed in a flat plate shape.

[0021] The protrusion 144 protrudes outward from the connection portion 142 in the perpendicular direction. The protrusion 144 is formed in a flat plate shape. As shown in FIG. 5, the protrusion 144 of the current collecting terminal 140 in the first cell unit 101 is connected to the protrusion 144 of the current collecting terminal 140 in the second cell unit 102. Similarly, the protrusion 144 of the current collecting terminal 140 in the third cell unit 103 is connected to the protrusion 144 of the current collecting terminal 140 in the fourth cell unit 104. As shown in FIGS. 5, 6, and 8, a pair of connected protrusions 144 include an overlapping portion 145 where they overlap each other.

[0022] The cover 150 covers the end of the electrode assembly 110 in the orthogonal direction, more specifically, the electrode tabs 114. The cover 150 is made of an insulating material (synthetic resin, etc.). As shown in FIGS. 2 and 3, the cover 150 covers the electrode tab 114 of the pair of electrode tabs 114 of the electrode assembly 110 that is located closer to the external terminal 400. As shown in FIG. 3, the cover 150 has a through hole h through which the protrusion 144 is inserted.

[0023] Of the multiple cell units 100 arranged side by side along the first direction, only the cell unit 100 arranged outermost in the first direction has a cover 150, and the other cell units 100 do not have a cover 150. For example, the first cell unit 101 has a cover 150, and the second cell unit 102 does not have a cover 150. The second cell unit 102 has the same structure as the first cell unit 101, except that it does not have a cover 150.

[0024] The laminated exterior body 160 houses the electrode assemblies 110, the spacer 120, the terminal member 130, a portion of the current collecting terminal 140, and the cover 150. The laminated exterior body 160 is made of a laminated film. As shown in FIGS. 5, 6, and 8, the laminated exterior body 160 has an edge portion 162. The edge portion 162 is formed by connecting (welding) the laminated films together. The protrusion 144 protrudes outward in the orthogonal direction from the edge portion 162 of the laminated exterior body 160.

[0025] 5, 6, and 8, the laminated exterior body 160 of one cell unit 100 of a pair of cell units 100 connected to each other and the laminated exterior body 160 of the other cell unit 100 include opposing surfaces 160s that face each other in an orthogonal direction. For example, the laminated exterior body 160 of the first cell unit 101 and the laminated exterior body 160 of the second cell unit 102 have opposing surfaces 160s that face each other. Each opposing surface 160s contacts the connecting portion 142 in the orthogonal direction.

[0026] The covering sheet 200 (see FIGS. 5 to 7) covers the multiple cell units 100. More specifically, the covering sheet 200 covers the multiple cell units 100 so as to collectively surround these cell units 100. The covering sheet 200 is made of an insulating material (synthetic resin, etc.).

[0027] The cell case 300 houses a plurality of cell units 100 and a covering sheet 200. The cell case 300 is made of, for example, aluminum. The cell case 300 is formed in a rectangular parallelepiped shape that is elongated in a first direction. As shown in FIGS. 1 and 2, the cell case 300 has a case body 310 and a lid 320.

[0028] The case body 310 is formed in the shape of a rectangular tube that is long in the first direction. The case body 310 surrounds the multiple cell units 100 and the cover sheet 200.

[0029] The lid 320 is connected to the case body 310 by welding or the like so as to close the opening of the case body 310 .

[0030] The external terminal 400 is provided on the lid 320. The external terminal 400 is connected to the current collecting terminal 140 of the cell unit 100 that is positioned closest to the lid 320 among the multiple cell units 100.

[0031] The intermediate member 500 is disposed between a pair of cell units 100 connected to each other. The intermediate member 500 is made of, for example, a synthetic resin. The intermediate member 500 has a pair of arm portions 510, at least one connecting portion 520, a pair of clamping portions 530, and a reinforcing wall 540.

[0032] The pair of arms 510 are arranged at positions sandwiching the overlapping portion 145 in the stacking direction. Each arm 510 extends in the orthogonal direction. Each arm 510 is formed in a flat plate shape. Each arm 510 is in contact with or close to the opposing surface 160s of the laminated exterior body 160. As shown in FIG. 6, the length L1 of each arm 510 in the orthogonal direction is 90% or more of the distance L2 between the opposing surface 160s of one cell unit and the opposing surface 160s of the other cell unit of a pair of cell units adjacent to each other in the orthogonal direction. The distance C between each arm 510 and the opposing surface 160s in the orthogonal direction is smaller than the dimension L of the overlapping portion 145 in the orthogonal direction.

[0033] The connecting portion 520 connects the pair of arm portions 510 together. In this embodiment, at least one connecting portion 520 has two connecting portions 520 provided at positions spaced apart from each other in the perpendicular direction. Each connecting portion 520 surrounds the protruding portion 144. Each connecting portion 520 is disposed between the edge portion 162 of the laminate exterior body 160 and the overlapping portion 145.

[0034] An adhesive member made of an insulating material may be filled into the area surrounded by the pair of arm portions 510 and the pair of connecting portions 520. It is preferable that the adhesive member covers the overlapping portion 145.

[0035] The pair of clamping portions 530 clamp each cell unit 100 in the stacking direction. Each clamping portion 530 is connected to the pair of arm portions 510. More specifically, one of the pair of clamping portions 530 is connected to one end of the pair of arm portions 510 in the first direction, and the other of the pair of clamping portions 530 is connected to the other end of the pair of arm portions 510 in the first direction. Each clamping portion 530 has a pair of opposing portions 532 and a pair of clamping pieces 534.

[0036] Each facing portion 532 faces the facing surface 160s of the laminate exterior body 160. Each facing portion 532 has a shape that extends from the end of each arm portion 510 in the orthogonal direction in a direction away from the current collecting terminal 140 in the stacking direction.

[0037] The pair of clamping pieces 534 clamp each laminate exterior body 160. Each clamping piece 534 is connected to the outer end of the opposing portion 532 in the stacking direction. Of the pair of clamping pieces 534 that clamp the first cell unit 101, the clamping piece 534 that is positioned on the inner side in the stacking direction is connected to the clamping piece 534 that is positioned on the inner side in the stacking direction of the pair of clamping pieces 534 that clamp the third cell unit 103. Similarly, of the pair of clamping pieces 534 that clamp the second cell unit 102, the clamping piece 534 that is positioned on the inner side in the stacking direction is connected to the clamping piece 534 that is positioned on the inner side in the stacking direction of the pair of clamping pieces 534 that clamp the fourth cell unit 104.

[0038] The reinforcing wall 540 connects a pair of opposing portions 532 that face each other in the first direction. The reinforcing wall 540 connects the outer ends of the opposing portions 532 in the second direction. The reinforcing wall 540 is in contact with or close to the covering sheet 200. This suppresses relative displacement of the intermediate member 500 with respect to the case body 310 in the second direction. The reinforcing wall 540 may be omitted.

[0039] 2, 5, 6, and 8, a through hole h10 is formed in the arm portion 510 of the pair that is positioned closer to the cell case 300 in the stacking direction. A through hole h40 is formed in the reinforcing wall 540. These through holes h10 and h40 enable welding of the overlapping portion 145 from the outside of the reinforcing wall 540 in the stacking direction. That is, after the intermediate member 500 is placed between a pair of cell units 100 adjacent to each other in the first direction, the overlapping portion 145 is welded through each of the through holes h10 and h40, and the multiple cell units 100 and the intermediate member 500 are inserted into the case body 310 along the first direction.

[0040] As described above, in the energy storage cell 1 of this embodiment, the length L1 of each arm portion 510 in the orthogonal direction is 90% or more of the distance L2 between a pair of opposing surfaces 160s opposing each other in the orthogonal direction, and therefore, for example, relative displacement of the pair of cell units 100 in a direction toward each other with respect to the cell case 300 due to vibration or the like is suppressed. Therefore, peeling of the overlapping portion 145 is suppressed.

[0041] Furthermore, the fact that the distance C between each arm portion 510 and the opposing surface 160s is smaller than the dimension L of the overlapping portion 145 in the orthogonal direction can also contribute to preventing the overlapping portion 145 from peeling off.

[0042] 9, the energy storage cell 1 may have only a plurality of cell units 100 arranged in a row along the first direction. In this case, the positive electrode external terminal 400 is provided on the lid 320 connected to one end of the case body 310 in the first direction, and the negative electrode external terminal 400 is provided on the lid 320 connected to the other end of the case body 310 in the first direction.

[0043] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0044] [Aspect 1] a pair of cell units connected to each other; an intermediate member disposed between the pair of cell units; a cell case that accommodates the pair of cell units and the intermediate member, Each of the cell units is At least one electrode body; a laminate exterior housing that houses the at least one electrode assembly; a current collecting terminal connected to the at least one electrode body and protruding from the laminate exterior body in a direction perpendicular to the stacking direction of the electrode bodies, The pair of cell units are arranged to be aligned in the perpendicular direction, the current collecting terminal of one of the pair of cell units is connected to the current collecting terminal of the other of the pair of cell units, the current collecting terminal of the one cell unit and the current collecting terminal of the other cell unit include overlapping portions in which they overlap each other, the laminate exterior body of the one cell unit and the laminate exterior body of the other cell unit include opposing surfaces that face each other in the orthogonal direction, The intermediate member is the overlapping portion is disposed between the two arms in the stacking direction, and the arms extend in the perpendicular direction; a length of each of the arms in the orthogonal direction that is 90% or more of the distance between the opposing surface of the one cell unit and the opposing surface of the other cell unit;

[0045] In this energy storage cell, the length of each arm in the orthogonal direction is 90% or more of the distance between the opposing surfaces of one cell unit and the other cell unit, which prevents the pair of cell units from moving toward each other relative to the cell casing, thereby preventing separation of the overlapping portions of the current collecting terminals.

[0046] [Aspect 2] 2. The energy storage cell according to claim 1, wherein the intermediate member further includes a connecting portion that connects the pair of arm portions to each other.

[0047] In this aspect, the pair of arms are prevented from moving relative to each other in the orthogonal direction, and therefore fluctuations in the distance between each arm and the opposing surface are suppressed.

[0048] [Aspect 3] 3. The energy storage cell according to aspect 1 or 2, wherein the intermediate member further includes a clamping portion connected to the pair of arm portions and clamping each of the cell units in the stacking direction.

[0049] In this embodiment, the relative position of the intermediate member in the stacking direction with respect to each cell unit is controlled.

[0050] [Aspect 4] The clamping unit is a pair of opposing portions each having a shape extending from an end of each of the arm portions in the orthogonal direction in a direction away from the current collecting terminal in the stacking direction and opposing the opposing surface; a pair of clamping pieces connected to outer ends of the opposing portions in the stacking direction and clamping each of the laminate exterior bodies.

[0051] [Aspect 5] the at least one electrode body includes a pair of electrode bodies arranged adjacent to each other in the stacking direction, Each of the pair of electrode bodies is a coated portion including an active material layer; an electrode tab formed on the outer side of the coated portion in the orthogonal direction, Each of the cell units is a spacer made of an insulating material and disposed between a pair of electrode tabs adjacent to each other in the stacking direction; a terminal member connected to an outer surface of the spacer in the orthogonal direction and connected to each of the electrode tabs; The current collecting terminal is a connection portion connected to an outer surface of the terminal member in the orthogonal direction; a protrusion extending outward in the orthogonal direction from the connection portion and protruding from the laminate exterior body; the protruding portion of the one cell unit and the protruding portion of the other cell unit include the overlapping portion, 5. The energy storage cell according to any one of aspects 1 to 4, wherein the opposing surface of the laminate exterior body is in contact with the connection portion.

[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 disclosure 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 cell unit, 101 first cell unit, 102 second cell unit, 103 third cell unit, 104 fourth cell unit, 110 electrode body, 112 coated portion, 114 electrode tab, 120 spacer, 130 terminal member, 140 current collecting terminal, 142 connection portion, 144 protrusion portion, 145 overlap portion, 150 cover, 160 laminate outer casing, 160s opposing surface, 162 edge portion, 200 covering sheet, 300 cell case, 310 case body, 320 lid, 400 external terminal, 500 intermediate member, 510 arm portion, 520 connecting portion, 530 clamping portion, 532 opposing portion, 534 clamping piece, 540 reinforcing wall.

Claims

1. a pair of cell units connected to each other; an intermediate member disposed between the pair of cell units; a cell case that accommodates the pair of cell units and the intermediate member, Each of the cell units is At least one electrode body; a laminate exterior housing that houses the at least one electrode assembly; a current collecting terminal connected to the at least one electrode body and protruding from the laminate exterior body in a direction perpendicular to the stacking direction of the electrode bodies, The pair of cell units are arranged to be aligned in the perpendicular direction, the current collecting terminal of one of the pair of cell units is connected to the current collecting terminal of the other of the pair of cell units, the current collecting terminal of the one cell unit and the current collecting terminal of the other cell unit include overlapping portions in which they overlap each other, the laminate exterior body of the one cell unit and the laminate exterior body of the other cell unit include opposing surfaces that face each other in the orthogonal direction, the intermediate member is disposed at a position sandwiching the overlapping portion in the stacking direction, and has a pair of arm portions extending in the perpendicular direction, A storage cell, wherein the length of each arm portion in the orthogonal direction is 90% or more of the distance between the opposing surface of one cell unit and the opposing surface of the other cell unit.

2. The energy storage cell according to claim 1 , wherein the intermediate member further includes a connecting portion that connects the pair of arm portions together.

3. The energy storage cell according to claim 2 , wherein the intermediate member further includes a clamping portion connected to the pair of arm portions and configured to clamp each of the cell units in the stacking direction.

4. The clamping unit is a pair of opposing portions each having a shape extending from an end of each of the arm portions in the orthogonal direction in a direction away from the current collecting terminal in the stacking direction and opposing the opposing surface; The energy storage cell according to claim 3 , further comprising: a pair of clamping pieces connected to outer ends of each of the opposing portions in the stacking direction and clamping each of the laminate exterior bodies.

5. the at least one electrode body includes a pair of electrode bodies arranged adjacent to each other in the stacking direction, Each of the pair of electrode bodies is a coated portion including an active material layer; an electrode tab formed on the outer side of the coated portion in the orthogonal direction, Each of the cell units is a spacer made of an insulating material and disposed between a pair of electrode tabs adjacent to each other in the stacking direction; a terminal member connected to an outer surface of the spacer in the orthogonal direction and connected to each of the electrode tabs; The current collecting terminal is a connection portion connected to an outer surface of the terminal member in the orthogonal direction; a protrusion extending outward in the orthogonal direction from the connection portion and protruding from the laminate exterior body; the protruding portion of the one cell unit and the protruding portion of the other cell unit include the overlapping portion, The energy storage cell according to claim 1 , wherein the opposing surface of the laminate exterior body is in contact with the connection portion.

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