Power storage cell

Abstract

To reduce an impregnation time of an electrolytic solution.SOLUTION: A power storage cell contains a following construction. The power storage cell contains: a case; an electrode body; and an electrolytic solution. The case houses the electrode body, and the electrolytic solution. The electrode body contains: a first electrode; a second electrode; and a separator. The separator contains a ridge-folding part, and a valley-folding part. In a length direction of the separator, the ridge-folding part and the valley-folding part are alternately arranged. In the ridge-folding part, the separator is folded so as to be ridge-folding toward an external side of the electrode body. In the valley-folding part, the separator is folded so as to be the valley-folding part toward the external side of the electrode body. The first electrode is arranged to an inner side of the ridge-folding part. In an inner side of the valley-folding part, the second electrode is arranged. A penetration hole is formed to a tip of at least one of the ridge-folding part and the valley-folding part.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] JP 2021-044133 A discloses a folded separator. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-044133 Summary of the Invention [Problem to be solved by the invention]

[0004] The energy storage cell includes an electrode body and an electrolyte. The electrode body has, for example, a zigzag structure. In the zigzag structure, the separator is folded in a zigzag shape. The separator is a porous film. The electrolyte permeates the separator, thereby impregnating the electrode body with the electrolyte. In the zigzag structure, the separator has a folded portion. Since the electrolyte has difficulty permeating the folded portion, it may take a long time to impregnate the electrolyte.

[0005] An object of the present disclosure is to shorten the impregnation time of the electrolyte. [Means for solving the problem]

[0006] 1. In one aspect of the present disclosure, an energy storage cell includes the following configuration. The energy storage cell includes a case, an electrode assembly, and an electrolyte. The case houses the electrode assembly and the electrolyte. The electrode assembly includes a first electrode, a second electrode, and a separator. The separator includes a mountain fold and a valley fold. The mountain fold and the valley fold are alternately arranged in the length direction of the separator. In the mountain fold, the separator is bent so as to form a mountain fold toward the outside of the electrode assembly. In the valley fold, the separator is bent so as to form a valley fold toward the outside of the electrode assembly. A first electrode is arranged inside the mountain fold. A second electrode is arranged inside the valley fold. A through hole is formed at an end of at least one of the mountain fold and the valley fold.

[0007] By forming through holes at the ends of the separator's folded parts (mountain folds and valley folds), it is expected that the electrolyte will easily pass through the folded parts, which is to say, it is expected that the time required for the electrolyte to be impregnated will be shortened.

[0008] 2. The energy storage cell according to "1" above may include, for example, the following configuration: The tip where the through hole is formed is recessed toward the inside of the electrode body.

[0009] The tip is recessed inward, so that a flow path for the electrolyte can be formed. The formation of the flow path is expected to shorten the impregnation time.

[0010] 3. The storage cell according to "1" or "2" 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, width direction, and thickness direction are perpendicular to one another. The tip of the mountain fold and the tip of the valley fold are each located at both ends in the height direction.

[0011] 4. The energy storage cell according to any one of "1" to "3" above may include, for example, the following configuration. The first electrode includes a first electrode tab. The second electrode includes a second electrode tab. In the width direction, the electrode body includes a first side end and a second side end. In the width direction, the second side end is located opposite the first side end. The first electrode tab is disposed at the first side end. The second electrode tab is disposed at the second side end.

[0012] 5. In one aspect of the present disclosure, the energy storage cell may include the following configuration. The energy storage cell includes a case, an electrode assembly, and an electrolyte. The case houses the electrode assembly and the electrolyte. The electrode assembly includes a first electrode, a second electrode, and a separator. The separator includes a mountain fold and a valley fold. The mountain fold and the valley fold are alternately arranged in the length direction of the separator. In the mountain fold, the separator is bent so as to form a mountain fold toward the outside of the electrode assembly. In the valley fold, the separator is bent so as to form a valley fold toward the outside of the electrode assembly. A first electrode is arranged inside the mountain fold. A second electrode is arranged inside the valley fold. A through hole is formed at an end of at least one of the mountain fold and the valley fold. The tip where the through hole is formed is recessed toward the inside of the 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 perpendicular to one another. The tip of the mountain fold and the tip of the valley fold are each disposed at both ends in the height direction. The first electrode includes a first electrode tab. The second electrode includes a second electrode tab. In the width direction, the electrode body includes a first side end and a second side end. In the width direction, the second side end is located opposite the first side end. The first electrode tab is disposed at the first side end. The second electrode tab is disposed at the second side end.

[0013] 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.

[0014] 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]

[0015] [Figure 1] FIG. 1 is a first schematic cross-sectional view showing an example of an electrode body in the present embodiment. [Diagram 2] FIG. 2 is a schematic plan view illustrating an example of a separator in the present embodiment. [Diagram 3] FIG. 2 is an enlarged view of region III in FIG. [Figure 4] FIG. 2 is a schematic perspective view showing an example of a storage cell according to the present embodiment. [Diagram 5] 1 is a schematic cross-sectional view illustrating an example of a storage cell according to an embodiment of the present invention. [Figure 6] FIG. 2 is a second schematic cross-sectional view showing an example of an electrode body in the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] 1. Electrode body FIG. 1 is a first schematic cross-sectional view showing an example of an electrode body in this embodiment. The electrode body 100 has a zigzag structure. The electrode body 100 includes a first electrode 110, a second electrode 120, and a separator 130. The separator 130 is folded in a zigzag shape. That is, the separator 130 includes mountain folds 132a and valley folds 132b. The T direction in FIG. 1 is the length direction of the separator 130. In the T direction, the mountain folds 132a and the valley folds 132b are alternately arranged. The "zigzag shape" can also be expressed as, for example, a "bellows shape" or an "accordion shape."

[0017] The H direction in FIG. 1 is the height direction of the electrode assembly 100. The tip of the mountain fold 132a is disposed at one end of the H direction. The tip of the valley fold 132b is disposed at the other end of the H direction. That is, the tip of the mountain fold 132a and the tip of the valley fold 132b are disposed at both ends of the H direction. At the mountain fold 132a, the separator 130 is bent so as to be mountain-folded toward the outside of the electrode assembly 100. At the valley fold 132b, the separator 130 is bent so as to be valley-folded toward the outside of the electrode assembly 100. The first electrode 110 is disposed inside the mountain fold 132a. The second electrode 120 is disposed inside the valley fold 132b. The second electrode 120 faces the first electrode 110 with the separator 130 sandwiched therebetween.

[0018] A through hole 132c is formed at the tip of at least one of the mountain folds 132a and the valley folds 132b. The through hole 132c may be formed at the tip of the mountain folds 132a or the valley folds 132b. The through hole 132c may be formed at the tip of both the mountain folds 132a and the valley folds 132b. It is expected that the electrolyte will pass through the through hole 132c, thereby shortening the impregnation time of the electrolyte.

[0019] 2 is a schematic plan view showing an example of a separator in this embodiment. The through hole 132c has any planar shape. The through hole 132c may be, for example, a circular hole, an elliptical hole, a square hole, an oblong hole, an oblong hole, or the like. The maximum diameter d of the through hole 132c may be, for example, 0.1 mm or more, 0.2 mm or more, 0.3 mm or more, 0.4 mm or more, 0.5 mm or more, 0.6 mm or more, 0.7 mm or more, 0.8 mm or more, 0.9 mm or more, or 1 mm or more. The maximum diameter d of the through hole 132c may be, for example, 5 mm or less, 3 mm or less, 2 mm or less, 1 mm or less, or 0.5 mm or less.

[0020] The through-hole 132c may extend linearly. For example, the through-hole 132c may extend along the mountain fold line La. For example, the through-hole 132c may intersect with the mountain fold line La. For example, the through-hole 132c may extend along the valley fold line Lb. For example, the through-hole 132c may intersect with the valley fold line Lb. For example, the linearly extending through-hole 132c may be formed by making a cut in the separator 130.

[0021] FIG. 3 is an enlarged view of region III in FIG. 1. The tip where the through hole 132c is formed may be recessed toward the inside of the electrode body 100. By recessing the tip, for example, it is expected that a flow path of the electrolyte will be formed in the depth direction (W direction) of FIG. 3. By forming the flow path, it is expected that the impregnation time of the electrolyte will be shortened. The recession amount A indicates the depth of the recess of the tip. The recession amount A may be, for example, any of 0.1 mm or more, 0.2 mm or more, 0.3 mm or more, 0.4 mm or more, 0.5 mm or more, 0.6 mm or more, 0.7 mm or more, 0.8 mm or more, 0.9 mm or more, or 1 mm or more. The recession amount A may be, for example, any of 5 mm or less, 3 mm or less, 2 mm or less, 1 mm or less, or 0.5 mm or less.

[0022] 2. Energy storage cells FIG. 4 is a schematic perspective view showing an example of a storage cell in this embodiment. The storage cell 1 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 in FIG. 4, etc. The "width direction" is the W direction in FIG. 4, etc. The "thickness direction" is the T direction in FIG. 4, etc. 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 an object.

[0023] Fig. 5 is a schematic cross-sectional view showing an example of a storage cell in this embodiment. Fig. 5 shows a cross section perpendicular to the T direction. The storage cell 1 includes a case 200, an electrode body 100, and an electrolyte (not shown). The electrolyte is a liquid electrolyte. The electrolyte may include, for example, an organic solvent and a lithium salt.

[0024] The electrode body 100 may be covered with an insulating film (not shown). The electrode body 100 may have, for example, a cubic outer shape. The electrode body 100 may have, for example, a rectangular parallelepiped outer shape. The electrode body 100 may have, for example, a flat rectangular parallelepiped shape. The "first aspect ratio" indicates the ratio of the width to the height in the electrode body 100. The first aspect ratio may be, for example, any of 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, any of 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" indicates the ratio of the thickness to the height in the electrode body 100. The second aspect ratio may be, for example, any of 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, any one of 1 or less, 0.5 or less, 0.3 or less, or 0.2 or less.

[0025] FIG. 6 is a second schematic cross-sectional view showing an example of the 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 of the storage cell 1 is parallel to 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] The separator 130 has electrical insulation properties. The separator 130 is porous. The separator 130 may include, for example, a microporous membrane 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.

[0030] Separator 130 includes zigzag fold portion 135. Zigzag fold portion 135 includes mountain fold portion 132a, flat portion 131, and valley fold portion 132b. In flat portion 131, separator 130 extends in a plane. In mountain fold portion 132a and valley fold portion 132b, separator 130 is folded back. Separator 130 is folded back so as to sandwich first electrode 110 or second electrode 120 alternately. Flat portion 131 sandwiches first electrode 110 or second electrode 120.

[0031] Separator 130 may further include, for example, an outer peripheral portion 136. Outer peripheral portion 136 may be wound so as to wrap zigzag portion 135. Note that separator 130 may be folded back at both ends in the W direction to form zigzag portions.

[0032] A through hole 132c is formed at the tip of at least one of the mountain folds 132a and the valley folds 132b. The through hole 132c may also penetrate the outer circumferential portion 136. The through hole 132c of the mountain folds 132a and the valley folds 132b and the through hole 132c of the outer circumferential portion 136 may be continuous or independent from each other.

[0033] The case 200 houses the electrolyte and the electrode assembly 100. The case 200 may be sealed. The case 200 may be sealed. The case 200 may include, for example, a can 210 and a lid 220. The can 210 has an opening. The opening opens in the H direction. The can 210 may be made of, for example, a metal. The can 210 may include, for example, Al or the like. The can 210 may include, for example, a bottom wall 212 and a peripheral wall 214. The bottom wall 212 may be, for example, flat. The planar shape of the bottom wall 212 may be, for example, rectangular. The peripheral wall 214 stands up from the bottom wall 212. The peripheral wall 214 may be, for example, a rectangular tube. The width of the peripheral wall 214 may be greater than the thickness of the peripheral wall 214. The height of the peripheral wall 214 may be greater than the thickness of the peripheral wall 214. It should be noted that "the thickness of the peripheral wall 214" here refers to the outer dimension of the case 200 in the thickness direction.

[0034] The lid 220 closes the opening of the can 210. The lid 220 may be welded to the peripheral wall 214. The lid 220 may be, for example, flat. The lid 220 may be made of metal. The lid 220 may include, for example, Al, etc. The lid 220 may include, for example, a pressure release valve 222, a sealing member 224, etc.

[0035] The pressure release valve 222 may be disposed, for example, near the center of the lid 220. The pressure release valve 222 releases the internal pressure of the case 200. When the internal pressure reaches or exceeds a set value, the pressure release valve 222 can be opened. The sealing member 224 seals the liquid injection hole 221. An electrolyte can be injected from the liquid injection hole 221.

[0036] A pair of external terminals 300 are fixed to the lid 220. The external terminals 300 are connected to the first electrode 110 or the second electrode 120. The external terminals 300 may be made of a metal, for example. The external terminals 300 may contain Al, Cu, Ni, or the like. The external terminals 300 may have an outer shape of a rectangular parallelepiped, for example. The external terminals 300 may be connected to a bus bar (not shown).

[0037] A pair of connecting members 400 connect the electrode tabs to the external terminal 300. The two connecting members 400 may have substantially the same structure. The electrode tabs indicate the first electrode tab 116 or the second electrode tab 126. The first electrode 110 includes the first electrode tab 116. The second electrode 120 includes the second electrode tab 126. In the W direction, the electrode body 100 includes a first side end portion 101 and a second side end portion 102. In the W direction, the second side end portion 102 is located on the opposite side to the first side end portion 101. The first electrode tab 116 is disposed at the first side end portion 101. The second electrode tab 126 is disposed at the second side end portion 102.

[0038] The connecting member 400 may include, for example, a current collecting tab 410, a sub-tab 420, and a connecting pin 430. The current collecting tab 410 includes a side portion 412 and an upper portion 414. The side portion 412 is located on a side of the electrode body 100 in the W direction. The upper portion 414 is located above the electrode body 100. The upper portion 414 extends from an upper end of the side portion 412 toward the inside in the W direction.

[0039] The sub-tab 420 connects the electrode tabs to the current collecting tab 410. The sub-tab 420 may include a first end 422 and a second end 424. The first end 422 is connected to the electrode tabs. The second end 424 is connected to the side portion 412.

[0040] The connecting pin 430 connects the current collecting tab 410 to the external terminal 300. The connecting pin 430 connects the upper portion 414 to the external terminal 300. For example, a lower end of the connecting pin 430 may be inserted into a through hole provided in the upper portion 414.

[0041] The insulating member 500 insulates the case 200 from the connecting member 400. The insulating member 500 may include a first portion 510, a second portion 520, a third portion 530, and a fourth portion 540, for example.

[0042] The first part 510 is fixed to the upper surface of the lid 220. The first part 510 is disposed between the lid 220 and the external terminal 300. The second part 520 is fixed to the lower surface of the lid 220. The second part 520 is disposed between the lid 220 and the upper part 414. The second part 520 is disposed between the lid 220 and a lower part of the connecting pin 430. The third part 530 is disposed between the connecting pin 430 and the lid 220. The third part 530 is cylindrical. The third part 530 surrounds the connecting pin 430. The first part 510, the second part 520 and the third part 530 are provided with through holes. The connecting pin 430 is inserted through the through holes.

[0043] The fourth part 540 is plate-shaped. It is fixed to the lower surface of the upper part 414. The fourth part 540 is disposed above the electrode body 100. In the fourth part 540, a through hole is provided below the pressure release valve 222. In the fourth part 540, a through hole is also provided below the liquid injection hole 221. [Explanation of symbols]

[0044] 1 Energy storage cell, 100 Electrode body, 101 First side end, 102 Second side end, 110 First electrode, 112 First current collector, 114 First active material layer, 116 First electrode tab, 120 Second electrode, 122 Second current collector, 124 Second active material layer, 126 Second electrode tab, 130 Separator, 131 Planar portion, 132a Mountain fold portion, 132b Valley fold portion, 132c Through hole, 135 Zigzag fold portion, 136 Outer periphery, 200 Case, 210 Can, 212 Bottom wall, 214 Peripheral wall, 220 Lid, 221 Injection hole, 222 Pressure release valve, 224 Sealing member, 300 External terminal, 400 Connecting member, 410 Current collecting tab, 412 Side portion, 414 Upper portion, 420 subtab, 422 first end, 424 second end, 430 connecting pin, 500 insulating member, 510 first part, 520 second part, 530 third part, 540 fourth part, A setback amount, III area, La mountain fold line, Lb valley fold line, d maximum diameter.

Claims

1. The battery includes a case, an electrode body, and an electrolyte. The case accommodates the electrode body and the electrolyte, The electrode assembly includes a first electrode, a second electrode, and a separator, the separator includes mountain folds and valley folds, The mountain folds and the valley folds are alternately arranged in a longitudinal direction of the separator, At the mountain fold portion, the separator is bent so as to form a mountain fold toward an outside of the electrode assembly, At the valley fold portion, the separator is bent so as to form a valley fold toward an outer side of the electrode assembly, The first electrode is disposed on the inner side of the mountain fold, The second electrode is disposed on the inner side of the valley fold, and A through hole is formed at a tip of at least one of the mountain fold portion and the valley fold portion. Energy storage cell.

2. The tip where the through hole is formed is recessed toward the inside of the electrode body. The storage cell according to claim 1 .

3. having 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, and The tip of the mountain fold and the tip of the valley fold are respectively disposed at both ends in the height direction. The storage cell according to claim 1 .

4. the first electrode includes a first electrode tab; the second electrode includes a second electrode tab; In the width direction, the electrode body includes a first side end portion and a second side end portion, In the width direction, the second side end portion is located on an opposite side to the first side end portion, the first electrode tab is disposed at the first side end; and The second electrode tab is disposed on the second side end. The storage cell according to claim 3 .

5. The battery includes a case, an electrode body, and an electrolyte. The case accommodates the electrode body and the electrolyte, The electrode assembly includes a first electrode, a second electrode, and a separator, the separator includes mountain folds and valley folds, The mountain folds and the valley folds are alternately arranged in a longitudinal direction of the separator, At the mountain fold portion, the separator is bent so as to form a mountain fold toward an outside of the electrode assembly, At the valley fold portion, the separator is bent so as to form a valley fold toward an outer side of the electrode assembly, The first electrode is disposed on the inner side of the mountain fold, The second electrode is disposed on the inner side of the valley fold, A through hole is formed at a tip of at least one of the mountain fold portion and the valley fold portion, The tip where the through hole is formed is recessed toward the inside of the electrode body, having 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 height direction, the width direction, and the thickness direction are perpendicular to each other, the tip of the mountain fold and the tip of the valley fold are disposed at both ends in the height direction, the first electrode includes a first electrode tab; the second electrode includes a second electrode tab; In the width direction, the electrode body includes a first side end portion and a second side end portion, In the width direction, the second side end portion is located on an opposite side to the first side end portion, the first electrode tab is disposed at the first side end; and The second electrode tab is disposed on the second side end. Energy storage cell.

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