Case, and manufacturing method for power storage cell

Abstract

To reduce bounce of an electrolyte solution at liquid injection.SOLUTION: A case is used to accommodate an electrode body and an electrolyte solution of a power storage cell. The case has a cuboid external shape. 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 first bottom wall has a rectangular planar shape. The first bottom wall has a long side direction and a short side direction. The long side direction is parallel to a long side of the first bottom wall. The short side direction is parallel to a short side of the first bottom wall. The first bottom wall includes a liquid injection port. The liquid injection port has an aspect ratio of less than 1. The aspect ratio represents a ratio of a maximum diameter of the liquid injection port in the short side direction to a maximum diameter of the liquid injection port in the long side direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a case and a method for manufacturing an energy storage cell. [Background technology]

[0002] JP 2019-145294 A discloses a liquid injection port. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-145294 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. The case houses the electrode body. The electrolyte is injected through an injection port provided in the case. Inside the case, the electrode body is impregnated with the electrolyte. Conventionally, the planar shape of the injection port is circular. In other words, the aspect ratio of the injection port is 1. The nozzle is inserted along the central axis of the injection port. The electrolyte is sprayed from the nozzle. The electrode body is disposed directly below the injection port. The electrolyte that collides with the electrode body may bounce back toward the injection port, reducing work efficiency.

[0005] An objective of the present disclosure is to reduce electrolyte splashback. [Means for solving the problem]

[0006] 1. In one aspect of the present disclosure, a case is provided. The case is used to house an electrode body and an electrolyte of a storage cell. The case has a rectangular parallelepiped outer shape. 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 first bottom wall has a rectangular planar shape. The first bottom wall has a longitudinal direction and a transverse direction. The longitudinal direction is parallel to the long side of the first bottom wall. The transverse direction is parallel to the short side of the first bottom wall. A liquid inlet is provided in the first bottom wall. The liquid inlet has an aspect ratio of less than 1. The aspect ratio indicates the ratio of the maximum diameter of the liquid inlet in the transverse direction to the maximum diameter of the liquid inlet in the longitudinal direction.

[0007] In one aspect of the present disclosure, the inlet has an aspect ratio of less than 1. A nozzle may be inserted obliquely with respect to the central axis of the inlet. The nozzle may be inclined along the longitudinal direction of the inlet. It is expected that the electrolyte is sprayed from an inclined nozzle to reduce the splashing of the electrolyte.

[0008] 2. The case described in "1" above may include, for example, the following configuration: The aspect ratio of the liquid injection port is 0.25 to 0.75.

[0009] 3. The case described in "1" or "2" above may include, for example, the following configuration. The case further includes an inner plate. The inner plate is disposed within the case. The inner plate extends in a direction from the first bottom wall toward the second bottom wall. A through hole is formed in the inner plate.

[0010] For example, the electrolyte may be sprayed through a nozzle inserted into the through hole of the inner plate. The inner plate may function as a shielding plate. That is, the inner plate is expected to block the electrolyte from bouncing back toward the injection port.

[0011] 4. In one aspect of the present disclosure, there is provided a method for producing a storage cell, the method for producing a storage cell including the following steps (a) to (d) in this order: (a) Prepare a case described in any one of items "1" to "3" above. (b) The electrode body is placed in the case. (c) Insert the nozzle into the case through the injection port. (d) With the nozzle tilted in the longitudinal direction, electrolyte is injected into the case through the nozzle.

[0012] It is expected that injecting the electrolyte from an inclined nozzle will reduce the amount of electrolyte splashing.

[0013] 5. The method for producing a storage cell described in "4" above may include, for example, the following configuration: In the above (a), the case described in "3" above is prepared. The above (d) includes injecting an electrolyte solution into the case from a nozzle while the nozzle is inserted into the through-hole of the inner plate.

[0014] It is expected that the electrolyte will be reduced by injecting the electrolyte while the nozzle is tilted and inserted into the through-hole in the inner plate, thereby reducing the amount of electrolyte that splashes back.

[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] 2 is a schematic flowchart of a method for producing a storage cell in the present embodiment. [Diagram 2] FIG. 4 is a schematic diagram showing an example of a case in the present embodiment. [Diagram 3] 4 is a schematic plan view showing a first bottom wall of the case in the present embodiment. FIG. [Figure 4] FIG. 2 is a schematic cross-sectional view showing an example of a case in 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 schematic cross-sectional view showing an example of an electrode body in the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] 1. Manufacturing method of energy storage cells 1 is a schematic flow chart of a method for manufacturing a storage cell in this embodiment. Hereinafter, the "method for manufacturing a storage cell in this embodiment" may be abbreviated as "this manufacturing method." This manufacturing method includes "(a) preparation of a case," "(b) storage of an electrode body," "(c) insertion of a nozzle," and "(d) injection," in this order.

[0019] (a) Case preparation FIG. 2 is a schematic diagram showing an example of a case in this embodiment. FIG. 3 is a schematic plan view showing a first bottom wall of the case in this embodiment. The manufacturing method includes preparing a case 200. The 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 in FIG. 2, etc. The "width direction" is the W direction in FIG. 2, etc. The "thickness direction" is the T direction in FIG. 2, 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 the object.

[0020] The case 200 may be made of, for example, metal. The case 200 may include, for example, Al or the like. The case 200 has a rectangular parallelepiped shape. The case 200 includes a first bottom wall 201, a peripheral wall 203, and a second bottom wall 202. The second bottom wall 202 faces the first bottom wall 201 in the H direction. The peripheral wall 203 has a rectangular cylindrical shape. The peripheral wall 203 connects the first bottom wall 201 and the second bottom wall 202.

[0021] The first bottom wall 201 has a rectangular planar shape. The second bottom wall 202 also has a rectangular planar shape. The first bottom wall 201 has a longitudinal direction and a lateral direction. The longitudinal direction is the L direction in FIG. 2. The L direction is parallel to the long side of the contour line of the first bottom wall 201. The L direction is parallel to the W direction. The lateral direction is the S direction in FIG. 2. The S direction is parallel to the short side of the contour line of the first bottom wall 201. The S direction is parallel to the T direction.

[0022] The first bottom wall 201 is provided with a liquid inlet 204. The liquid inlet 204 may be disposed at any position within the first bottom wall 201. The liquid inlet 204 may be disposed, for example, near the center of the first bottom wall 201. The liquid inlet 204 has an aspect ratio of less than 1. The aspect ratio is the ratio of the maximum diameter of the liquid inlet 204 in the S direction to the maximum diameter of the liquid inlet 204 in the L direction. The aspect ratio may be, for example, 0.9 or less, 0.8 or less, 0.7 or less, 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, or 0.2 or less. The aspect ratio may be, for example, 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, 0.5 or more, 0.6 or more, 0.7 or more, or 0.8 or more. The aspect ratio may be, for example, 0.25 to 0.75.

[0023] The maximum diameter of the liquid injection port 204 in the S direction may be, for example, any of 1 mm or more, 2 mm or more, 3 mm or more, 4 mm or more, 5 mm or more, 6 mm or more, 7 mm or more, 8 mm or more, 9 mm or more, or 10 mm or more. The maximum diameter of the liquid injection port 204 in the S direction may be, for example, any of 20 mm or less, 10 mm or less, 9 mm or less, 8 mm or less, 7 mm or less, 6 mm or less, 5 mm or less, 4 mm or less, 3 mm or less, 2 mm or less, or 1 mm or less.

[0024] The liquid inlet 204 may have any planar shape as long as the aspect ratio is less than 1. The planar shape of the liquid inlet 204 may be, for example, an ellipse, a diamond, a rectangle, a rectangle with rounded corners, or the like.

[0025] FIG. 4 is a schematic cross-sectional view showing an example of the case in this embodiment. The case 200 may further include, for example, an inner plate 205. The inner plate 205 can block the electrolyte from bouncing back from the electrode body 100. The inner plate 205 may be held, for example, by the first bottom wall 201. The inner plate 205 may be held, for example, by the peripheral wall 203. The inner plate 205 extends in the H direction. That is, the inner plate 205 extends in a direction from the first bottom wall 201 toward the second bottom wall 202. The inner plate 205 may be parallel to the H direction. The inner plate 205 may be inclined with respect to the H direction. The dimension of the inner plate 205 in the H direction may be set so as not to contact the electrode body 100. The inner plate 205 may be adjacent to the end of the liquid inlet 204 in the W direction (L direction). The inner plate 205 may be disposed directly below the end of the liquid inlet 204. The inner plate 205 may be spaced apart in the W direction from the end of the liquid pouring hole 204 .

[0026] The inner plate 205 may have a through hole 206. A nozzle 207 is inserted through the through hole 206. The through hole 206 in the inner plate 205 may have any planar shape. The planar shape of the through hole 206 may be a shape that allows the nozzle 207 to easily pass through. The planar shape of the through hole 206 may be, for example, a circle, an ellipse, a rounded rectangular shape, a rectangular shape, or the like. The clearance between the through hole 206 and the nozzle 207 may be, for example, 0.1 to 1 mm.

[0027] (b) Storage of the electrode body This manufacturing method includes storing the electrode body 100 in the case 200. For example, the first bottom wall 201 may form a lid. For example, the second bottom wall 202 and the peripheral wall 203 may form a can. The can has an opening. The opening may open in the H direction, for example. The electrode body 100 can be stored in the can through the opening. After the electrode body 100 is stored, the opening is closed with a lid. For example, the lid may be welded to the can by laser processing.

[0028] (c) Inserting the nozzle This manufacturing method includes inserting a nozzle 207 into the case 200 from the liquid injection port 204. The nozzle 207 may be inserted through a through hole 206 of an inner plate 205. The nozzle 207 is inserted at an incline with respect to the H direction. The nozzle 207 may be inserted at an incline in the L direction (W direction). The angle (inclination angle θ) between the axial direction of the nozzle 207 and the H direction may be, for example, more than 0°, 5° or more, 15° or more, 30° or more, 45° or more, 60° or more, or 75° or more. The inclination angle θ may be, for example, less than 90°, 75° or less, 60° or less, 45° or less, 30° or less, 15° or less, or 5° or less.

[0029] (d) Liquid injection This manufacturing method includes injecting the electrolyte from the nozzle 207 into the case 200 while the nozzle 207 is tilted in the L direction (W direction). Because the nozzle 207 is tilted, it is considered that the electrolyte that collides with the electrode body 100 is less likely to bounce back toward the injection port 204. When the nozzle 207 is inserted into the through-hole 206 of the inner plate 205, it is expected that the inner plate 205 will also block the rebound of the electrolyte. Since there is less rebound of the electrolyte, for example, it is expected that the injection speed of the electrolyte will be improved.

[0030] After a predetermined amount of electrolyte is injected, the injection hole 204 is closed with a sealing member. The sealing member may be welded to the first bottom wall 201.

[0031] 2. Energy storage cells A storage cell suitable for this manufacturing method will be described below. Fig. 5 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 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.

[0032] 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 be a single body. The case 200 may be composed of a plurality of members. The case 200 may include, for example, a can 210 and a lid 220. The can 210 includes a second bottom wall 202 and a peripheral wall 203. The width of the peripheral wall 203 may be greater than the thickness of the peripheral wall 203. The height of the peripheral wall 203 may be greater than the thickness of the peripheral wall 203. Note that the "thickness of the peripheral wall 203" here indicates the outer dimension of the case 200 in the T direction.

[0033] The lid 220 closes the opening of the can 210. The lid 220 includes a first bottom wall 201. The lid 220 may be, for example, flat. The lid 220 may include, for example, a pressure release valve 222, a sealing member 224, and the like.

[0034] The pressure relief valve 222 releases the internal pressure of the case 200. When the internal pressure reaches or exceeds a set value, the pressure relief valve 222 can be opened. The sealing member 224 seals the liquid inlet 204.

[0035] 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 electrode body 100 may be covered with, for example, an insulating film (not shown).

[0036] The "first aspect ratio" refers to the ratio of the width to the height in the electrode body 100. 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 in the electrode body 100. 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.

[0037] The electrode body 100 may have any structure. The electrode body 100 may be, for example, a wound type. The electrode body 100 may be, for example, a laminated type.

[0038] FIG. 6 is a schematic cross-sectional view showing an example of an electrode assembly in this embodiment. The electrode assembly 100 in FIG. 4 is a laminated type. 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 laminated. That is, the T direction of the storage cell 1 is parallel to the lamination 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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."

[0044] 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.

[0045] The energy storage cell 1 further includes external terminals 300. The 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 metal, for example. The external terminals may contain Al, Cu, Ni, or the like. The external terminals 300 may have, for example, a rectangular parallelepiped shape. The external terminals 300 may be connected to a bus bar (not shown).

[0046] The pair of connecting members 400 connect the electrode tabs and the external terminals 300. The electrode tabs indicate the first electrode tabs 116 or the second electrode tabs 126. The two connecting members 400 may have substantially the same structure.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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 assembly 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 port 204. [Explanation of symbols]

[0053] 1 storage cell, 100 electrode body, 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 flat portion, 132 folded portion, 135 zigzag portion, 136 outer periphery, 200 case, 201 first bottom wall, 202 second bottom wall, 203 peripheral wall, 204 liquid inlet, 205 inner plate, 206 through hole 207 nozzle, 210 can, 220 lid, 222 pressure relief valve, 224 sealing member, 300 outer terminal, 400 connecting member, 410 current collecting tab, 412 side portion, 414 upper portion, 420 sub-tab, 422 first end, 424 second end, 430 connecting pin, 500 insulating member, 510 first part, 520 second part, 530 third part, 540 fourth part.

Claims

1. A case for housing an electrode assembly and an electrolyte of a storage cell, It has a rectangular parallelepiped shape, 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 first bottom wall has a rectangular planar shape, The first bottom wall has a longitudinal direction and a lateral direction, The longitudinal direction is parallel to a long side of the first bottom wall, The short direction is parallel to a short side of the first bottom wall, A liquid inlet is provided in the first bottom wall, the inlet has an aspect ratio of less than 1; and The aspect ratio indicates a ratio of a maximum diameter of the liquid injection port in the short direction to a maximum diameter of the liquid injection port in the long direction. case.

2. the aspect ratio is from 0.25 to 0.75; The case according to claim 1.

3. The case further includes an inner plate; The inner plate is disposed within the case, The inner plate extends in a direction from the first bottom wall toward the second bottom wall, and A through hole is formed in the inner plate. The case according to claim 1.

4. (a) preparing a case according to any one of claims 1 to 3; (b) housing the electrode body in the case; (c) inserting a nozzle into the case through the injection port; and (d) injecting the electrolyte from the nozzle into the case while the nozzle is inclined in the longitudinal direction; In this order: A method for manufacturing a storage cell.

5. In the step (a), the case according to claim 3 is prepared, and The step (d) includes injecting the electrolyte from the nozzle into the case while the nozzle is inserted into the through hole of the inner plate. The method for producing the storage cell according to claim 4 .

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