Power storage cell

Abstract

To accelerate the permeation of an electrolyte solution.SOLUTION: A power storage cell includes an external terminal, a lead plate, and an electrode body. The electrode body has a height direction, a width direction, and a thickness direction. The height direction, the width direction, and the thickness direction are orthogonal to each other. The electrode body includes a plurality of electrodes. The plurality of electrodes are stacked in the thickness direction. Each of the plurality of electrodes includes an electrode tab. The electrode tab extends outward in the width direction. The lead plate electrically connects the external terminal and the electrode tab. At least a part of the lead plate extends in the height direction along end faces of the plurality of electrodes. One or more through holes are formed in the lead plate. The through hole penetrates the lead plate in the width direction. The lead plate includes a bonding surface. The bonding surface is bonded to the electrode tab. The bonding surface has unevenness.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] JP2015-097194A discloses a current collector. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-097194 A Summary of the Invention [Problem to be solved by the invention]

[0004] An electrode body can be formed by stacking a plurality of electrodes. During injection, the electrolyte penetrates into the gaps between the electrodes from a direction perpendicular to the stacking direction of the electrodes, so that the electrode body can be impregnated with the electrolyte. To connect each of the plurality of electrodes to a lead plate (current collector), the lead plate is arranged in a direction perpendicular to the stacking direction. The lead plate may hinder the movement of the electrolyte, which may delay the impregnation of the electrolyte.

[0005] The objective of the present disclosure is to facilitate impregnation of the electrolyte. [Means for solving the problem]

[0006] The energy storage cell includes an external terminal, a lead plate, and an electrode body. The electrode body has a height direction, a width direction, and a thickness direction. The height direction, width direction, and thickness direction are mutually perpendicular. The electrode body includes a plurality of electrodes. The plurality of electrodes are stacked in the thickness direction. Each of the plurality of electrodes includes an electrode tab. The electrode tab extends outward in the width direction. The lead plate electrically connects the external terminal and the electrode tab. At least a portion of the lead plate extends in the height direction along end faces of the plurality of electrodes. One or more through holes are formed in the lead plate. The through holes penetrate the lead plate in the width direction. The lead plate includes a bonding surface. The bonding surface is bonded to the electrode tab. The bonding surface has irregularities.

[0007] The through holes formed in the lead plate can form a flow path for the electrolyte. The electrolyte passes through the through holes, and the impregnation of the electrolyte can be promoted. The formation of the through holes may reduce the bonding strength between the lead plate and the electrode tab. It is expected that the reduction in the bonding strength can be reduced by providing the bonding surface of the lead plate with irregularities.

[0008] Hereinafter, an embodiment of the present disclosure (hereinafter, may be abbreviated as "the present embodiment") will be described. However, the present embodiment does not limit the technical scope of the present disclosure. The present embodiment is illustrative in all respects. The present embodiment is non-restrictive. The technical scope of the present disclosure includes all modifications within the meaning and scope equivalent to the description of the claims. For example, it is also originally intended that any configuration may be extracted from the present embodiment and arbitrarily combined.

[0009] Geometric terms should not be interpreted in a strict sense. Examples of geometric terms include "parallel," "perpendicular," and the like. For example, "parallel" may deviate slightly from the strict meaning of "parallel." Geometric terms may include, for example, tolerances, errors, and the like in design, work, and manufacturing. The dimensional relationships in each figure may not match the actual dimensional relationships. The dimensional relationships in each figure may be changed to help the reader understand. For example, the length, width, thickness, and the like may be changed. Furthermore, some configurations may be omitted. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a first schematic diagram showing an example of a power storage cell in this embodiment. [Diagram 2] FIG. 2 is a second schematic diagram showing an example of the power storage cell in this embodiment. [Diagram 3] FIG. 3 is a schematic cross-sectional view showing an example of an electrode body in this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] FIG. 1 is a first schematic diagram showing an example of a storage cell in this embodiment. The storage cell 1 has a height direction, a width direction, and a thickness direction. The height direction, width direction, and thickness direction are perpendicular to each other. The "height direction" is the H direction. The "width direction" is the W direction. The "thickness direction" is the T direction. The height direction may be parallel to the vertical direction, for example. The width direction and the thickness direction may be parallel to the horizontal direction, for example. "Height" refers to the dimension in the height direction. "Width" refers to the dimension in the width direction. "Thickness" refers to the dimension in the thickness direction, or the thickness of an object.

[0012] The energy storage cell 1 includes a can 210, a lid 220, an external terminal 300, a lead plate 410, an electrode body 100, and an electrolyte (not shown). The lid 220 closes the opening of the can 210, thereby sealing the energy storage cell 1. The external terminal 300 is provided on the lid 220. A liquid injection port 221 may be provided on the lid 220. The electrolyte can be injected from the liquid injection port 221. The electrolyte is a liquid electrolyte. The electrolyte may contain, for example, a lithium salt and an organic solvent.

[0013] The electrode assembly 100 includes a plurality of electrodes. The term "electrode" refers collectively to a positive electrode 110 and a negative electrode 120. The electrodes are stacked in the T direction. Each of the electrodes includes an electrode tab. The positive electrode 110 includes a positive electrode tab 112p. The negative electrode 120 includes a negative electrode tab 122n. The electrode tabs extend outward in the W direction.

[0014] The lead plate 410 may be made of, for example, a metal. The lead plate 410 may have a thickness of, for example, 1 to 3 mm. The lead plate 410 may include, for example, Al, Ni, Cu, or the like. The lead plate 410 electrically connects the external terminal 300 and the positive electrode tab 112p. The lead plate 410 electrically connects the external terminal 300 and the negative electrode tab 122n. At least a part of the lead plate 410 extends in the H direction along the end faces of the multiple electrodes. One or more through holes 10 are formed in the lead plate 410. Each of the through holes 10 penetrates the lead plate 410 in the W direction. The planar shape of the through hole 10 is arbitrary. The planar shape of the through hole 10 may be a circle, an ellipse, a rectangle, or the like. The through hole 10 may have a maximum diameter of, for example, 1 to 10 mm.

[0015] FIG. 2 is a second schematic diagram showing an example of a storage cell in this embodiment. The lead plate 410 includes a joint surface 11. The joint surface 11 is joined to the positive electrode tab 112p or the negative electrode tab 122n. The joint surface 11 includes irregularities. The irregularities can be formed, for example, by blasting or the like. The joint surface 11 may have an arithmetic mean roughness (Ra) of, for example, 1 to 1000 μm. After joining, the portion including the joint surface 11 is folded as shown by the curved arrow f, thereby forming the shape shown in FIG. 1. The positive electrode tab 112p and the negative electrode tab 122n may also have a through hole 10. The through hole 10 of the electrode tab may be larger or smaller than the through hole 10 of the lead plate 410.

[0016] 3 is a schematic cross-sectional view showing an example of an electrode assembly in this embodiment. The electrode assembly 100 includes one or more positive electrodes 110, one or more negative electrodes 120, and one or more separators 130. The positive electrodes 110 and the negative electrodes 120 are alternately stacked in the T direction. That is, the T direction is the stacking direction of the electrodes. The number of the positive electrodes 110 and the negative electrodes 120 may be any of 2 or more, 5 or more, 10 or more, 50 or more, or 100 or more. The number of the positive electrodes 110 and the negative electrodes 120 may be any of 200 or less, 100 or less, 50 or less, 10 or less, or 5 or less.

[0017] The positive electrode 110 may include, for example, a positive electrode collector 112 and a positive electrode active material layer 114. The positive electrode collector 112 may include, for example, an Al foil or the like. The positive electrode tab 112p may be a part of the positive electrode collector 112. The positive electrode tab 112p may be joined to an end of the positive electrode collector 112 in the W direction. The positive electrode active material layer 114 is disposed on a surface of the positive electrode collector 112. The positive electrode active material layer 114 may be disposed on only one side of the positive electrode collector 112. The positive electrode active material layer 114 may be disposed on both sides of the positive electrode collector 112. The positive electrode active material layer 114 includes a positive electrode active material. The positive electrode active material may include, for example, a lithium nickel composite oxide or the like.

[0018] The negative electrode 120 may include, for example, a negative electrode current collector 122 and a negative electrode active material layer 124. The negative electrode current collector 122 may include, for example, Cu foil or the like. The negative electrode tab 122n may be a part of the negative electrode current collector 122. The negative electrode tab 122n may be joined to an end of the negative electrode current collector 122 in the W direction. The negative electrode active material layer 124 is disposed on a surface of the negative electrode current collector 122. The negative electrode active material layer 124 may be disposed on only one side of the negative electrode current collector 122. The negative electrode active material layer 124 may be disposed on both sides of the negative electrode current collector 122. The negative electrode active material layer 124 includes a negative electrode active material. The negative electrode active material may include, for example, graphite, SiO, Si, or the like.

[0019] The separator 130 has electrical insulation properties. The separator 130 is porous. The separator 130 may include, for example, a microporous film made of polyolefin. The thickness of the separator 130 may be, for example, 5 to 50 μm, 5 to 30 μm, or 5 to 15 μm. The separator 130 separates the positive electrode 110 from the negative electrode 120. The separator 130 may be, for example, two or more sheets. For example, the separator 130 may be inserted between each of the positive electrode 110 and the negative electrode 120.

[0020] Separator 130 may be, for example, a single sheet. For example, separator 130 may include zigzag fold portion 135. Separator 130 is folded in a zigzag shape at zigzag fold portion 135. The zigzag shape may also be expressed as, for example, a "bellows shape" or an "accordion shape."

[0021] The zigzag fold portion 135 includes a planar portion 131 and a folded portion 132. In the planar portion 131, the separator 130 extends in a planar shape. In the folded portion 132, the separator 130 is folded. The folded portion 132 is disposed at both ends in the H direction. The separator 130 is folded so as to sandwich the positive electrode 110 or the negative electrode 120 alternately. The planar portion 131 sandwiches the positive electrode 110 or the negative electrode 120. The separator 130 may further include, for example, an outer peripheral portion 136. The outer peripheral portion 136 may be wound so as to wrap the zigzag fold portion 135. Note that the zigzag fold portion may be formed by folding the separator 130 at both ends in the W direction. [Explanation of symbols]

[0022] 1 storage cell, 10 through hole, 11 joint surface, 100 electrode body, 110 positive electrode, 112 positive electrode current collector, 112p positive electrode tab, 114 positive electrode active material layer, 120 negative electrode, 122 negative electrode current collector, 122n negative electrode tab, 124 negative electrode active material layer, 130 separator, 131 flat portion, 132 folded portion, 135 zigzag folded portion, 136 outer periphery, 210 can, 220 lid, 221 filling port, 300 external terminal, 410 lead plate, f curved arrow.

Claims

[Claim 1] The external terminal, the lead plate, and the electrode body are included. The electrode body has a height direction, a width direction, and a thickness direction, the height direction, the width direction, and the thickness direction are perpendicular to each other, The electrode assembly includes a plurality of electrodes, The plurality of electrodes are stacked in the thickness direction, each of the plurality of electrodes includes an electrode tab; The electrode tab extends outward in the width direction, the lead plate electrically connects the external terminal and the electrode tab; At least a portion of the lead plate extends in the height direction along end surfaces of the plurality of electrodes, One or more through holes are formed in the lead plate, the through hole penetrates the lead plate in the width direction, The lead plate includes a bonding surface, the bonding surface is bonded to the electrode tab; and The joining surface has projections and recesses. Energy storage cell.

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