Power storage cell

Abstract

To accelerate permeation of an electrolyte solution into an electrode body.SOLUTION: A power storage cell includes a case, an electrode body, and an electrolyte solution. The electrode body includes a first electrode and a second electrode. The case accommodates the electrode body and the electrolyte solution. The case includes a first bottom wall, a peripheral wall, and a second bottom wall. The second bottom wall faces the first bottom wall. The peripheral wall connects between the first bottom wall and the second bottom wall. The peripheral wall has a square tubular shape. The peripheral wall includes a pair of main walls and a pair of side walls. The pair of main walls face each other and the pair of side walls face each other. The pair of side walls connect between the pair of main walls. Each of the pair of main walls has a larger area than each of the pair of side walls. A first through hole is formed in the first bottom wall. A second through hole is formed in at least one of the pair of side walls. The second through hole exists at a position closer to the second bottom wall than to the first bottom wall.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] JP 2022-067369 A discloses a battery case having an electrolyte injection port and a suction port. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-067369 A Summary of the Invention [Problem to be solved by the invention]

[0004] The energy storage cell includes a case, an electrode body, and an electrolyte. After the electrode body is housed in the case, the electrolyte is injected through an inlet provided in the case. From the viewpoint of increasing capacity, it is required to reduce the clearance between the case and the electrode body inside the case. By reducing the clearance, the flow path of the electrolyte after injection is reduced. As a result, there is a possibility that the electrolyte will not penetrate sufficiently into the electrode body.

[0005] In order to improve the permeation of the electrolyte, it is conceivable to provide an air intake port in the case at a position opposite the electrolyte injection port. When the electrolyte is injected, the gas in the case is sucked in through the air intake port, and it is expected that the suction force will promote the permeation of the electrolyte. However, there is a demand for further promotion of the electrolyte permeation.

[0006] An object of the present disclosure is to promote the permeation of an electrolyte into an electrode body. [Means for solving the problem]

[0007] 1. The energy storage cell includes a case, an electrode body, and an electrolyte. The electrode body includes a first electrode and a second electrode. The case houses the electrode body and the electrolyte. The case includes a first bottom wall, a peripheral wall, and a second bottom wall. The second bottom wall faces the first bottom wall. The peripheral wall connects the first bottom wall and the second bottom wall. The peripheral wall is a rectangular tube. The peripheral wall includes a pair of main walls and a pair of side walls. The pair of main walls face each other. The pair of side walls face each other. The pair of side walls connect the pair of main walls. Each of the pair of main walls has an area larger than each of the pair of side walls. A first through hole is formed in the first bottom wall. A second through hole is formed in at least one of the pair of side walls. The second through hole is located closer to the second bottom wall than the first bottom wall.

[0008] For example, the first through hole may be used as a liquid inlet and the second through hole may be used as an air inlet. For example, the first through hole may be used as an air inlet and the second through hole may be used as a liquid inlet.

[0009] By having the first through hole and the second through hole have the positional relationship of "1" above, the case can be held so that the liquid inlet is located higher than the air inlet in the vertical direction. By having the liquid inlet located higher than the air inlet, gravity can act on the electrolyte in addition to suction force. It is expected that the penetration of the electrolyte is promoted by the synergistic effect of suction force and gravity.

[0010] By having the first through hole and the second through hole have the positional relationship of "1" above, the intake direction can cross the vertical direction. It is expected that the penetration of the electrolyte is further promoted by the action of forces from multiple directions on the electrolyte.

[0011] 2. The storage cell described in "1" above may include, for example, the following configuration. The storage cell 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 first bottom wall and the second bottom wall are disposed at both ends in the height direction. The pair of side walls are disposed at both ends in the width direction. The pair of main walls are disposed at both ends in the thickness direction. In the case, a first groove is formed on a surface of at least one of the pair of main walls. The position of the first groove in the width direction corresponds to the position of the first through hole in the width direction. The first groove extends in the height direction.

[0012] The first grooves formed in the surface of the main wall can form a flow path for the electrolyte. For example, it is expected that the electrolyte injected from the first through-holes will be smoothly introduced into the first grooves, thereby accelerating the permeation of the electrolyte.

[0013] 3. The energy storage cell according to "1" or "2" above may include, for example, the following configuration: A second groove is formed on the surface of the electrode body. The position of the second groove in the width direction corresponds to the position of the first through hole in the width direction. The second groove extends in the height direction.

[0014] The second grooves formed on the surface of the electrode body can form a flow path for the electrolyte. For example, it is expected that the electrolyte injected from the first through-holes will be smoothly introduced into the second grooves, thereby accelerating the penetration of the electrolyte.

[0015] 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.

[0016] 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]

[0017] [Figure 1] FIG. 4 is a schematic diagram showing an example of a case in the present embodiment. [Diagram 2] 1 is a schematic cross-sectional view illustrating an example of a storage cell according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a schematic cross-sectional view showing an example of an electrode body in the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] FIG. 1 is a schematic diagram showing an example of a case in this embodiment. Case 200 may have, for example, 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" indicates the dimension in the height direction. "Width" indicates the dimension in the width direction. "Thickness" indicates the dimension in the thickness direction, or the thickness of the object.

[0019] The case 200 may have, for example, a rectangular parallelepiped shape. The "first aspect ratio" refers to the ratio of the width to the height of the case 200. The first aspect ratio may be, for example, 1 or more, 1.5 or more, 2 or more, 2.5 or more, 3 or more, 5 or more, or 10 or more. The first aspect ratio may be, for example, 10 or less, 5 or less, 3 or less, 2.5 or less, 2 or less, or 1.5 or less. The "second aspect ratio" refers to the ratio of the thickness to the height of the case 200. The second aspect ratio may be, for example, 0.1 or more, 0.2 or more, 0.3 or more, 0.5 or more, or 1 or more. The second aspect ratio may be, for example, 1 or less, 0.5 or less, 0.3 or less, or 0.2 or less.

[0020] The case 200 includes a first bottom wall 201, a peripheral wall 203, and a second bottom wall 202. The first bottom wall 201 may form a lid. The first bottom wall 201 may be provided with, for example, a pair of external terminals 300. The first bottom wall 201 may be provided with, for example, a pressure release valve (not shown) or the like.

[0021] The peripheral wall 203 and the second bottom wall 202 may form a can. The first bottom wall 201 and the second bottom wall 202 are disposed at both ends in the H direction. In the H direction, the second bottom wall 202 faces the first bottom wall 201. The peripheral wall 203 connects the first bottom wall 201 and the second bottom wall 202. The peripheral wall 203 is a rectangular tube. The peripheral wall 203 includes a pair of main walls 203a and a pair of side walls 203b. The pair of main walls 203a are disposed at both ends in the T direction. The pair of main walls 203a face each other. The pair of side walls 203b are disposed at both ends in the W direction. The pair of side walls 203b face each other. The pair of side walls 203b connect the pair of main walls 203a. Each of the pair of main walls 203a has a larger area than each of the pair of side walls 203b.

[0022] A first through hole 11 is formed in the first bottom wall 201. The first through hole 11 can be closed by a first plug (not shown). A second through hole 12 is formed in at least one of the pair of side walls 203b. The second through hole 12 can be closed by a second plug (not shown). The second through hole 12 is located closer to the second bottom wall 202 than the first bottom wall 201. The second through hole 12 is located lower in the H direction than the first through hole 11. The second through hole 12 may be formed in either one of the side walls 203b. The second through hole 12 may be formed in both side walls 203b. A plurality of second through holes 12 may be formed. The positions of the second through holes 12 in the H direction may differ between the two side walls 203b.

[0023] 2 is a schematic cross-sectional view showing an example of a storage cell in this embodiment. The storage cell 1 includes a case 200, an electrode assembly 100, and an electrolyte (not shown). The case 200 houses the electrode assembly 100 and the electrolyte. The electrolyte is a liquid electrolyte. The electrolyte may include, for example, an organic solvent and a lithium salt.

[0024] In the case 200, the first groove 21 may be formed on the surface of at least one of the pair of main walls 203a. The first groove 21 may be formed on either one of the main walls 203a. The first groove 21 may be formed on both of the main walls 203a. The position of the first groove 21 in the W direction may correspond to the position of the first through hole 11 in the W direction. The position of the first groove 21 in the W direction may coincide with the position of the first through hole 11 in the W direction. The first groove 21 extends in the depth direction of FIG. 2 (H direction in FIG. 1). The first groove 21 may extend from the first bottom wall 201 to the second bottom wall 202. The first groove 21 may extend linearly, for example. The first groove 21 may be formed by laser processing, for example.

[0025] The second groove 22 may be formed on the surface of the electrode body 100. The position of the second groove 22 in the W direction may correspond to the position of the first through hole 11 in the W direction. The position of the second groove 22 in the W direction may coincide with the position of the first through hole 11 in the W direction. The second groove 22 may face the first groove 21 in the T direction. The second groove 22 may have a width smaller than that of the first groove 21. The second groove 22 extends in the H direction. The second groove 22 may cross the surface of the electrode body 100 in the H direction. For example, the second groove 22 may be formed by forming a groove on the surface of an electrode included in the electrode body 100. The groove of the electrode may be formed by, for example, stripe coating or the like.

[0026] Here, the first groove 21 and the second groove 22 are collectively referred to as "groove". The groove may have any cross-sectional shape. The cross-sectional shape of the groove may be, for example, V-shaped, U-shaped, rectangular, or trapezoidal. The width of the groove may be, for example, 10 to 1000 μm, 100 to 500 μm, or 300 to 500 μm. The ratio of the groove depth to the thickness of the side wall 203b may be, for example, 0.1 to 0.9, or 0.3 to 0.7. The pitch between adjacent grooves 10 may be, for example, 0.1 to 10 mm. The shapes and sizes of the multiple grooves 10 may all be the same or different from each other.

[0027] FIG. 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 first electrodes 110, one or more second electrodes 120, and one or more separators 130. In the T direction, the first electrodes 110 and the second electrodes 120 are alternately stacked. That is, the T direction is the stacking direction of the first electrodes 110 and the second electrodes 120. The number of the first electrodes 110 and the second 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 first electrodes 110 and the second electrodes 120 may be any of 200 or less, 100 or less, 50 or less, 10 or less, or 5 or less.

[0028] The second electrode 120 has a different polarity than the first electrode 110. For example, the first electrode 110 may be a positive electrode and the second electrode 120 may be a negative electrode. For example, the first electrode 110 may be a negative electrode and the second electrode 120 may be a positive electrode.

[0029] The first electrode 110 may include, for example, a first current collector 112 and a first active material layer 114. The first current collector 112 may include, for example, a metal foil or the like. The metal foil may include, for example, Al, Cu, Ni, Ti, Fe, or the like. The first active material layer 114 is disposed on a surface of the first current collector 112. The first active material layer 114 may be disposed on only one side of the first current collector 112. The first active material layer 114 may be disposed on both sides of the first current collector 112. The first active material layer 114 includes a positive electrode active material or a negative electrode active material. The positive electrode active material may include, for example, a lithium nickel composite oxide, or the like. The negative electrode active material may include, for example, graphite, SiO, Si, or the like.

[0030] The second electrode 120 may include, for example, a second current collector 122 and a second active material layer 124. The second current collector 122 may include, for example, a metal foil or the like. The second active material layer 124 is disposed on a surface of the second current collector 122. The second active material layer 124 may be disposed on only one side of the second current collector 122. The second active material layer 124 may be disposed on both sides of the second current collector 122. The second active material layer 124 includes a positive electrode active material or a negative electrode active material. The second active material layer 124 may have the same area as the first active material layer 114, or may have a different area. For example, the area of ​​the second active material layer 124 may be larger than the area of ​​the first active material layer 114. The ratio of the area of ​​the second active material layer 124 to the area of ​​the first active material layer 114 may be, for example, any of 1.01 or more, 1.05 or more, or 1.1 or more. The ratio of the area of ​​the second active material layer 124 to the area of ​​the first active material layer 114 may be, for example, any of 1.1 or less, 1.05 or less, or 1.01 or less.

[0031] 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 first electrode 110 from the second 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 first electrode 110 and the second electrode 120.

[0032] 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."

[0033] The zigzag fold portion 135 includes a flat portion 131 and a folded portion 132. In the flat portion 131, the separator 130 extends in a flat 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 alternately sandwich the first electrode 110 or the second electrode 120. The flat portion 131 sandwiches the first electrode 110 or the second 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]

[0034] 1 storage cell, 10 groove, 11 first through hole, 12 second through hole, 21 first groove, 22 second groove, 100 electrode body, 110 first electrode, 112 first current collector, 114 first active material layer, 120 second electrode, 122 second current collector, 124 second active material layer, 130 separator, 131 flat portion, 132 folded portion, 135 zigzag folded portion, 136 outer periphery, 200 case, 201 first bottom wall, 202 second bottom wall, 203 peripheral wall, 203a main wall, 203b side wall, 300 external terminal.

Claims

[Claim 1] The battery includes a case, an electrode body, and an electrolyte. The electrode body includes a first electrode and a second electrode, The case accommodates the electrode body and the electrolyte, The case includes a first bottom wall, a peripheral wall, and a second bottom wall; The second bottom wall faces the first bottom wall, The peripheral wall connects the first bottom wall and the second bottom wall, The peripheral wall is in the shape of a rectangular tube, The peripheral wall includes a pair of main walls and a pair of side walls, The pair of main walls face each other, The pair of side walls face each other, the pair of side walls connect the pair of main walls, Each of the pair of main walls has an area larger than each of the pair of side walls, A first through hole is formed in the first bottom wall, A second through hole is formed in at least one of the pair of side walls, and The second through hole is located closer to the second bottom wall than to the first bottom wall. Energy storage cell.

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