Power storage cell

Abstract

To provide a power storage cell capable of improving an energy density.SOLUTION: A power storage cell 1 comprises a pair of electrode bodies 110 each consisting of a wound body. Each of the electrode bodies 110 includes a coated part 112, a non-coated part 114, and a collector tab 116 protruding from the non-coated part. The non-coated part 114 has an outer end surface S1, an inner end surface S2, and a coupling surface S3. The collector tab 116 protrudes from at least one of the inner end surface S2 and the coupling surface S3. The outer end surface S1 in one electrode body 110 is opposed to the inner end surface S2 in the other electrode body 110. The inner end surface S2 in one electrode body is opposed to the outer end surface S1 in the other electrode body. The coupling surface S3 in one electrode body is opposed to the coupling surface S3 in the other electrode body in a direction crossing an axial direction. The collector tab 116 in one electrode body is connected with the collector tab 116 in the other electrode body.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] For example, Japanese Patent Application Laid-Open No. 2016-207516 discloses a battery including a wound electrode assembly, a battery case that houses the wound electrode assembly, and electrode terminals connected to current collecting tabs of the wound electrode assembly. The current collecting tabs protrude upward from a power generation region. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-207516 Summary of the Invention [Problem to be solved by the invention]

[0004] In the electricity storage cell described in JP 2016-207516 A, it is preferable that the energy density is high.

[0005] An object of the present disclosure is to provide a storage cell that can improve energy density. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided a storage cell comprising a pair of electrode bodies each formed of a wound body, each of the electrode bodies including a coated portion including a current collecting foil and an active material layer provided on the current collecting foil, an uncoated portion protruding from the coated portion in an axial direction of the coated portion and constituted only by the current collecting foil, and a current collecting tab protruding from the uncoated portion, the uncoated portion having an outer end face formed on the outside in the axial direction, an inner end face formed inside the outer end face in the axial direction, and a connecting surface connecting the outer end face and the inner end face, and the current collecting tab has a surface that connects the inner end face and the connecting surface. The connecting surface of one of the pair of electrode bodies faces the connecting surface of the other electrode body in a direction intersecting the axial direction, and the current collecting tab of one of the electrode bodies faces the connecting surface of the other electrode body in a direction intersecting the axial direction. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a storage cell that can improve energy density. [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 front view of the cell unit. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. 10 is a perspective view showing a modified example of the electrode body. 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 a front view of a cell unit. Fig. 3 is a front view of an electrode assembly. Fig. 4 is a perspective view of the electrode assembly. This storage cell 1 is mounted, for example, on the bottom of a vehicle.

[0011] As shown in FIGS. 1 to 4, the energy storage cell 1 includes a plurality of cell units 100, a cell case 300, and an external terminal 400.

[0012] The plurality of cell units 100 includes at least a pair of cell units 100. Each cell unit 100 has an electrode assembly 110 and a laminate exterior body 160.

[0013] The electrode assembly 110 is composed of a wound body in which a positive electrode sheet and a negative electrode sheet are wound with a separator interposed therebetween. The electrode assembly 110 is formed in a shape that is long in the axial direction of the wound body (the left-right direction in FIG. 3). The electrode assembly 110 has a coated portion 112, an uncoated portion 114, and a current collecting tab 116.

[0014] The coated portion 112 includes a current collecting foil F (see FIG. 3) and an active material layer M (see FIG. 3) provided on the current collecting foil F. The current collecting foil F is made of a metal foil. The active material layer M is provided on the surface of the current collecting foil F. In FIGS. 3 and 4, the coated portion 112 is shown with a dot pattern.

[0015] The uncoated portion 114 protrudes in the axial direction from the coated portion 112. The uncoated portion 114 is composed only of the current collecting foil F. The uncoated portion 114 has an outer end surface S1, an inner end surface S2, and a connecting surface S3.

[0016] The outer end surface S1 is formed on the outer side in the axial direction and is formed to be substantially flat.

[0017] The inner end surface S2 is formed inside the outer end surface S1 in the axial direction and is formed to be substantially flat.

[0018] The connecting surface S3 connects the outer end surface S1 and the inner end surface S2. The connecting surface S3 intersects with the axial direction. In this embodiment, the connecting surface S3 is perpendicular to the axial direction.

[0019] 3, the outer end surface S1 of one electrode body 110 of the pair of electrode bodies 110 faces the inner end surface S2 of the other electrode body 110. The inner end surface S2 of one electrode body 110 of the pair of electrode bodies 110 faces the outer end surface S1 of the other electrode body 110. The coupling surface S3 of one electrode body 110 of the pair of electrode bodies 110 faces the coupling surface S3 of the other electrode body 110 in a direction intersecting the axial direction.

[0020] The current collecting tab 116 protrudes from the uncoated portion 114. In this embodiment, the current collecting tab 116 protrudes from the inner end surface S2. The current collecting tab 116 is made of a current collecting foil F. The current collecting tab 116 is integrally connected to the current collecting foil F that constitutes the uncoated portion 114. As shown in Figures 2 and 3, the current collecting tab 116 of one electrode body 110 is connected to the current collecting tab 116 of the other electrode body 110.

[0021] The laminated exterior body 160 houses the electrode assembly 110. The laminated exterior body 160 is made of a laminated film. As shown in FIG. 2, the laminated exterior body 160 has an edge portion 162. The edge portion 162 is formed by connecting (welding) pieces of laminated film together. The current collecting tab 116 protrudes from the edge portion 162 of the laminated exterior body 160.

[0022] The laminate exterior body 160 has an outer covering portion 162a, an inner covering portion 162b, and a connecting covering portion 162c. The outer covering portion 162a faces the outer end surface S1. The inner covering portion 162b faces the inner end surface S2. The connecting covering portion 162c faces the connecting surface S3. The current collecting tab 116 protrudes from the inner covering portion 162b.

[0023] The cell case 300 houses a plurality of cell units 100. The cell case 300 is made of, for example, aluminum. The cell case 300 is formed in a rectangular parallelepiped shape. As shown in FIG. 1 , the cell case 300 has a case body 310 and a lid 320.

[0024] The case body 310 is formed in a rectangular cylindrical shape. The case body 310 surrounds the multiple cell units 100. The multiple cell units 100 may be covered with a covering sheet (not shown) made of an insulating material (synthetic resin, etc.), and the case body 310 may surround the multiple cell units 100 and the covering sheet.

[0025] 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. The lid 320 is provided with a pair of external terminals 400.

[0026] As described above, in the energy storage cell 1 of this embodiment, the connecting surfaces S3 of the pair of electrode bodies 110 face each other in the intersecting direction that intersects the axial direction. In other words, a portion of the uncoated portion 114 of one electrode body 110 and a portion of the uncoated portion 114 of the other electrode body 110 overlap each other in the intersecting direction. This reduces the axial dimension of each electrode body 110 compared to when the uncoated portions 114 of the pair of electrode bodies 110 do not overlap each other in the intersecting direction and the outer end faces of the uncoated portions 114 face each other in the axial direction. This makes it possible to increase the size of each electrode body 110 by that amount, i.e., improve the energy density.

[0027] As shown in FIG. 5, the current collecting tab 116 may protrude from the coupling surface S3 in the intersecting direction.

[0028] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0029] [Aspect 1] A pair of electrode bodies each made up of a wound body is provided, Each of the electrode bodies is a coated portion including a current collecting foil and an active material layer provided on the current collecting foil; an uncoated portion protruding from the coated portion in the axial direction of the coated portion and constituted only by the current collecting foil; a current collecting tab protruding from the uncoated portion, The uncoated portion is an outer end surface formed on the outer side in the axial direction; an inner end surface formed inside the outer end surface in the axial direction; a connecting surface connecting the outer end surface and the inner end surface, the current collecting tab protrudes from at least one of the inner end surface and the connecting surface; the outer end surface of one of the pair of electrode bodies faces the inner end surface of the other electrode body, the inner end surface of one of the pair of electrode bodies faces the outer end surface of the other electrode body, the connecting surface of one of the pair of electrode bodies faces the connecting surface of the other electrode body in a direction intersecting the axial direction, A storage cell, wherein the current collecting tab of one of the electrode bodies is connected to the current collecting tab of the other of the electrode bodies.

[0030] In this energy storage cell, the connecting surfaces of the pair of electrode bodies face each other in a direction intersecting the axial direction, so the dimension of each electrode body in the axial direction is reduced compared to when the outer end faces of the pair of electrode bodies face each other in the axial direction, which makes it possible to increase the size of each electrode body by that amount, i.e., to improve the energy density.

[0031] [Aspect 2] Further provided is a laminate exterior body that houses each of the electrode assemblies, The laminate exterior body is an outer covering portion facing the outer end surface; an inner covering portion facing the inner end surface; a connecting cover portion facing the connecting surface.

[0032] 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]

[0033] 1 energy storage cell, 100 cell unit, 110 electrode body, 112 coated portion, 114 uncoated portion, 116 current collecting tab, 160 laminated exterior body, 162 edge portion, 162a outer coating portion, 162b inner coating portion, 162c connecting coating portion, 300 cell case, 400 external terminal, S1 outer end surface, S2 inner end surface, S3 connecting surface.

Claims

1. A pair of electrode bodies each made up of a wound body is provided, Each of the electrode bodies is a coated portion including a current collecting foil and an active material layer provided on the current collecting foil; an uncoated portion protruding from the coated portion in the axial direction of the coated portion and constituted only by the current collecting foil; a current collecting tab protruding from the uncoated portion, The uncoated portion is an outer end surface formed on the outer side in the axial direction; an inner end surface formed inside the outer end surface in the axial direction; a connecting surface connecting the outer end surface and the inner end surface, the current collecting tab protrudes from at least one of the inner end surface and the connecting surface; the outer end surface of one of the pair of electrode bodies faces the inner end surface of the other electrode body, the inner end surface of one of the pair of electrode bodies faces the outer end surface of the other electrode body, the connecting surface of one of the pair of electrode bodies faces the connecting surface of the other electrode body in a direction intersecting the axial direction, A storage cell, wherein the current collecting tab of one of the electrode bodies is connected to the current collecting tab of the other of the electrode bodies.

2. Further provided is a laminate exterior body that houses each of the electrode assemblies, The laminate exterior body is an outer covering portion facing the outer end surface; an inner covering portion facing the inner end surface; The energy storage cell according to claim 1 , further comprising a connecting covering portion facing the connecting surface.

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