Battery case manufacturing method

Abstract

To enhance a degree-of-freedom of a dimension in one direction of an opening formed in a case main body.SOLUTION: A manufacturing method of a battery case based on the present disclosure, includes a step (S1) of preparing a cylinder body 10 having a first opening end 11 and a second opening end 12 to both sides in a first direction D1; a step (S2) of blocking the first opening end 11 with a first plate-like member 20; a step (S3) of blocking the second opening end 12 with a second plate-like member 30; a step (S4) of obtaining a case main body 210 in which cutting edges 10E, 20E, and 30E of a cylinder body 10, a first plate-like member 20, a second plate-like member 30 are served as an opening OP by cutting the cylinder body 10, the first plate-like member 20, and the second plate-like member 30 along a surface parallel to the first direction D1 in a state where the first opening end 11 is blocked by the first plate-like member 20, and the second opening end 12 is blocked by the second plate-like member 30; and a step (S5) of blocking the opening OP of the case main body 210 with a lid part 250.SELECTED DRAWING: Figure 6C

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a battery case. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2021-158014 (Patent Document 1) discloses a method for manufacturing a battery case in which a sealing plate is integrally attached to the opening of a cylindrical case body with a bottom. In this manufacturing method, a previously prepared blank is drawn and ironed to form an intermediate product with a bottom having an elliptical or oval cross-section. The intermediate product is then further drawn or ironed multiple times to gradually reduce the radii of curvature of the four corners so that the cross-section becomes rectangular, and the thickness of the side walls that form the corners is reduced to form the final product that will become the case body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-158014 Summary of the Invention [Problem to be solved by the invention]

[0004] To further reduce the height of the storage cells, there is a demand for a battery case that is longer in one dimension perpendicular to the opening direction of the case body. However, it is difficult to form an opening that is longer in the one direction using the drawing process disclosed in Patent Document 1. For this reason, conventional methods for manufacturing battery cases have imposed limitations on the dimension of the opening in the one direction.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a method for manufacturing a battery case that can increase the degree of freedom in the dimension in one direction of an opening formed in a case body. [Means for solving the problem]

[0006] A method for manufacturing a battery case according to the present disclosure is a method for manufacturing a battery case including a bottomed, cylindrical case body capable of accommodating an electrode assembly and having a bottom and an opening opposite the bottom, and a lid for closing the opening. The method includes the steps of: preparing a cylindrical body having a first opening end and a second opening end on both sides in one direction, closing the first opening end with a first plate-shaped member, closing the second opening end with a second plate-shaped member, cutting the cylindrical body, the first plate-shaped member, and the second plate-shaped member along a plane parallel to one direction while the first opening end is closed with the first plate-shaped member and the second opening end is closed with the second plate-shaped member to obtain a case body having openings along the cut edges of the cylindrical body, the first plate-shaped member, and the second plate-shaped member, and closing the opening of the case body with the lid.

[0007] According to the above configuration, a cylindrical body having a first open end and a second open end on each side can be prepared without relying on drawing. It is also possible to prepare a cylindrical body that is relatively long in the one direction. Then, by cutting the cylindrical body, the first plate member, and the second plate member along a plane parallel to the one direction, a case body having an opening that is relatively long in the one direction can be easily obtained. In other words, the manufacturing method of a battery case according to the present disclosure allows for greater flexibility in the dimension of the opening formed in the case body in the one direction. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to increase the degree of freedom in the dimension of the opening of the case body in one direction. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view illustrating a storage cell according to an embodiment of the present disclosure. [Figure 2] 2 is a cross-sectional view of the storage cell of FIG. 1 as viewed in the direction of the arrows along line II-II. [Figure 3]3 is a cross-sectional view of the electrode body of FIG. 2 as seen from the direction of the arrows along line III-III. [Figure 4] FIG. 10 is a perspective view showing a storage cell according to a modified example of the present disclosure. [Figure 5] FIG. 1 is a flow diagram illustrating a method for manufacturing a battery case according to an embodiment of the present disclosure. [Figure 6] 6A to 6D are schematic diagrams showing the process from the cylindrical body preparation step to the cutting step in chronological order. [Figure 7] FIG. 10 is a schematic diagram showing a third closing step. DETAILED DESCRIPTION OF THE INVENTION

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present disclosure will be described with reference to the accompanying drawings, in which the same or equivalent elements are designated by the same reference numerals.

[0011] [Energy storage cell] First, a description will be given of a storage cell according to an embodiment of the present disclosure. This storage cell includes a battery case manufactured by a battery case manufacturing method according to an embodiment of the present disclosure. Fig. 1 is a perspective view showing a storage cell according to an embodiment of the present disclosure. Fig. 2 is a cross-sectional view of the storage cell of Fig. 1 as viewed in the direction of the arrows II-II.

[0012] As shown in FIGS. 1 and 2, the energy storage cell 1 includes an electrode assembly 100, a battery case 200, a pair of external terminals 300, a pair of connecting members 400, and an insulating member 500.

[0013] Fig. 3 is a cross-sectional view of the electrode assembly of Fig. 2, seen from the direction of the arrows along line III-III. As shown in Fig. 3, the electrode assembly 100 includes a plurality of electrodes 110, 120 and a separator .

[0014] 3, the multiple electrodes 110, 120 are arranged side by side in a thickness direction T. In this embodiment, the thickness direction T is perpendicular to the height direction H. The multiple electrodes 110, 120 include multiple positive electrodes 110 and multiple negative electrodes 120.

[0015] Each positive electrode 110 is formed in a rectangular shape that is long in the width direction W. The width direction W is a direction perpendicular to both the thickness direction T and the height direction H. Each positive electrode 110 has a positive electrode current collector foil 112 and positive electrode active material layers 114 provided on both sides of the positive electrode current collector foil 112. The positive electrode current collector foil 112 has a positive electrode tab 112p (see FIG. 2) on which the positive electrode active material layer 114 is not provided. The positive electrode tab 112p protrudes toward one side in the width direction W.

[0016] Each negative electrode 120 is formed in a rectangular shape that is long in the width direction. Each negative electrode 120 has a negative electrode current collector foil 122 and a negative electrode active material layer 124 provided on both sides of the negative electrode current collector foil 122. As shown in FIG. 2, the negative electrode current collector foil 122 has a negative electrode tab 122n (see FIG. 2) on which the negative electrode active material layer 124 is not provided. The negative electrode tab 122n protrudes toward the other side in the width direction.

[0017] The separator 130 provides insulation between the positive electrode 110 and the negative electrode 120. The separator 130 is made of an insulating material and has minute voids that allow ions to pass through. As shown in Figure 3, the separator 130 is formed in a zigzag shape.

[0018] The separator 130 has a rectangular shape before being folded in a zigzag shape. The separator 130 is disposed between the electrodes 110, 120 while being folded in a zigzag shape. The separator 130 has a plurality of intervening portions 132a, a plurality of upper folded portions 132b, a plurality of lower folded portions 132c, and an outermost covering portion 132d.

[0019] Each intervening portion 132a is interposed between a pair of electrodes 110, 120 adjacent to each other in one direction. In other words, each intervening portion 132a has the function of insulating between the positive electrode 110 and the negative electrode 120. Each intervening portion 132a is formed of a rectangular region.

[0020] Each upper folded portion 132b connects an upper end portion of one of the plurality of intervening portions 132a to an upper end portion of another intervening portion 132a adjacent to the one intervening portion 132a on one side in one direction of the plurality of intervening portions 132a. In this embodiment, the upper folded portion 132b is disposed above the positive electrode 110.

[0021] Each lower folded portion 132c connects the lower end of one of the plurality of intervening portions 132a to the lower end of another of the plurality of intervening portions 132a that is adjacent to the one intervening portion on the other side in one direction. In this embodiment, the lower folded portion 132c is disposed below the negative electrode 120. In other words, the negative electrode 120 is disposed on the lower folded portion 132c.

[0022] The outermost covering portion 132d collectively covers each of the upper folded portions 132b and each of the lower folded portions 132c. More specifically, the outermost covering portion 132d collectively covers all of the electrodes 110, 120, all of the intervening portions 132a, all of the upper folded portions 132b, and all of the lower folded portions 132c while being wound around a central axis parallel to the width direction. The end 132e of the outermost covering portion 132d is set in a range that does not overlap with the positive electrode active material layer 114 and the negative electrode active material layer 124 in one direction. In this embodiment, the end 132e of the outermost covering portion 132d is provided below each of the electrodes 110, 120. The peripheral surfaces and bottom surfaces of the multiple electrodes 110, 120 and the separator 130 are covered with an insulating film 150 (see FIG. 7 described below, not shown in FIGS. 2 and 3).

[0023] As shown in Figures 1 and 2, the battery case 200 houses the electrode assembly 100. The battery case 200 houses an electrolyte solution (not shown). The battery case 200 is sealed. The battery case 200 is made of a metal such as aluminum or an aluminum alloy.

[0024] The battery case 200 has a cylindrical outer shape with a bottom. The battery case 200 has a case body 210 and a lid portion 250. The case body has a bottom portion 220, a first side surface portion 231, a second side surface portion 232, a first end surface portion 241, and a second end surface portion 242.

[0025] The bottom portion 220 has a flat plate-like outer shape. The bottom portion 220 extends in a plane direction perpendicular to the height direction H. When viewed from the height direction H, the bottom portion 220 has a substantially rectangular outer shape.

[0026] The bottom portion 220 has a pair of long sides 221 and a pair of short sides 222. The long sides 221 extend along the width direction W. The short sides 222 extend along the thickness direction T. The length of each of the pair of long sides 221 is longer than the length of each of the pair of short sides 222.

[0027] The first side surface portion 231 stands up from the bottom portion 220. The direction in which the first side surface portion 231 stands up is the height direction H. Specifically, the first side surface portion 231 stands up from one of the pair of long side portions 221. In this embodiment, the first side surface portion 231 and the bottom portion 220 are integrally formed without being welded.

[0028] The second side surface portion 232 stands up from the bottom portion 220 while facing the first side surface portion 231. Therefore, the direction in which the second side surface portion 232 stands up is also the height direction H. Specifically, the second side surface portion 232 stands up from the other of the pair of long side portions 221. In this embodiment, the second side surface portion 232 and the bottom portion 220 are integrally formed without being welded.

[0029] The first end surface portion 241 is joined by welding to one of the pair of short side portions 222 of the bottom portion 220. The first end surface portion 241 extends in the height direction H from one of the pair of short side portions 222. The first end surface portion 241 is joined to both the first side surface portion 231 and the second side surface portion 232 by welding.

[0030] The second end surface portion 242 is joined by welding to the other of the pair of short side portions 222 of the bottom portion 220. The first end surface portion 241 extends in the height direction H from the other of the pair of short side portions 222. The first end surface portion 241 is joined by welding to both the first side surface portion 231 and the second side surface portion 232.

[0031] Case body 210 also has an opening OP. Opening OP is located opposite bottom 220. Opening OP is formed by the edges of first side surface portion 231, second side surface portion 232, first end surface portion 241, and second end surface portion 242 that are located on the opposite side from bottom 220.

[0032] The lid portion 250 closes the opening OP. The lid portion 250 is connected to the opening OP by welding or the like. The lid portion 250 is formed in a flat plate shape.

[0033] The lid portion 250 has a pressure release valve 272 and a sealing member 274. The pressure release valve 272 is formed in the center of the lid portion 250. The pressure release valve 272 is formed to rupture when the internal pressure of the battery case 200 reaches or exceeds a predetermined pressure. When the pressure release valve 272 ruptures, gas inside the battery case 200 is released to the outside of the battery case 200 through the pressure release valve 272, thereby reducing the internal pressure of the battery case 200.

[0034] The sealing member 274 seals a liquid filling port h formed in the lid portion 250. The liquid filling port h is a through-hole for injecting an electrolyte into the battery case 200 during the manufacturing process of the energy storage cell 1. The liquid filling port h is sealed with the sealing member 274 after the electrolyte is injected into the battery case 200 through the liquid filling port h.

[0035] The pressure release valve 272 and the sealing member 274 may be disposed in a location other than the lid portion 250. Fig. 4 is a perspective view showing an energy storage cell according to a modified example of the present disclosure. As shown in Fig. 4, the first end surface portion 241a may have the pressure release valve 272a and the sealing member 274a. The second end surface portion 242a may have the pressure release valve 272a and the sealing member 274a.

[0036] As shown in Figures 1 and 2, a pair of external terminals 300 are fixed to the battery case 200. One of the pair of external terminals 300 is a positive electrode external terminal, and the other is a negative electrode external terminal. Each external terminal 300 is fixed to the upper surface of the lid portion 250 via an upper insulating portion 510, which will be described later. Each external terminal 300 is made of a metal such as aluminum.

[0037] The pair of connecting members 400 connect the plurality of electrode tabs 112p, 122n to the external terminals 300. One connecting member 400 connects the plurality of positive electrode tabs 112p to the positive electrode external terminals 300, and the other connecting member 400 connects the plurality of negative electrode tabs 122n to the negative electrode external terminals 300. Since the pair of connecting members 400 have substantially the same structure, only one of the connecting members 400 will be described below.

[0038] The connecting member 400 includes a current collecting tab 410 , a sub-tab 420 , and a connecting pin 430 .

[0039] The current collecting tab 410 has a side portion 412 and an upper portion 414. The side portion 412 is located on a side of the electrode assembly 100 in the width direction. The upper portion 414 is located above the electrode assembly 100. The upper portion 414 extends from the upper end of the side portion 412 toward the inside in the width direction.

[0040] The subtabs 420 connect the multiple positive electrode tabs 112p to the current collecting tab 410. One end 422 of the subtab 420 is connected to the multiple positive electrode tabs 112p by welding or the like, and the other end 424 of the subtab 420 is connected to the side portion 412 of the current collecting tab 410 by welding or the like.

[0041] The connecting pin 430 connects the current collecting tab 410 and the external terminal 300. The connecting pin 430 connects the upper part 414 and the external terminal 300. Specifically, the lower end of the connecting pin 430 is inserted into a through hole provided in the upper part 414 and connected to the upper part 414 by welding or the like, and the upper end of the connecting pin 430 is inserted into a through hole provided in the external terminal 300 and connected to the external terminal 300 by welding, crimping or the like.

[0042] The insulating member 500 provides insulation between the battery case 200 and the connecting member 400. The insulating member 500 has an upper insulating portion 510, a lower insulating portion 520, an insulating cylinder 530, and an insulating plate 540.

[0043] The upper insulating part 510 is fixed to the upper surface of the lid part 250. The upper insulating part 510 is disposed between the lid part 250 and the external terminal 300. The upper insulating part 510 is provided with an insertion hole through which the connecting pin 430 is inserted.

[0044] Lower insulating part 520 is fixed to the lower surface of lid part 250. Lower insulating part 520 is disposed between lid part 250 and upper part 414 and the lower part of connecting pin 430. Lower insulating part 520 has an insertion hole through which connecting pin 430 is inserted.

[0045] The insulating cylinder 530 is disposed between the connecting pin 430 and the lid portion 250. The insulating cylinder 530 is formed in a cylindrical shape and surrounds the connecting pin 430.

[0046] The insulating plate 540 is fixed to the lower surface of the upper part 414. The insulating plate 540 is disposed above the electrode assembly 100. Through holes are provided in the insulating plate 540 in a portion located below the pressure release valve 272 and a portion located below the liquid injection port h.

[0047] The insulating member 500 that insulates one of the pair of connecting members 400 (for example, the connecting member 400 electrically connected to the positive electrode tab 112p) from the battery case 200 may not have the upper insulating portion 510. In this case, the external terminal 300 may be in direct contact with the battery case 200, or another conductive member may be disposed between the external terminal 300 and the battery case 200 in place of the upper insulating portion 510.

[0048] [Battery case manufacturing method] Next, a method for manufacturing a battery case according to an embodiment of the present disclosure will be described. FIG. 5 is a flow diagram showing a method for manufacturing a battery case according to an embodiment of the present disclosure. As shown in FIG. 5, the method for manufacturing a battery case according to an embodiment of the present disclosure includes, in this order, a cylindrical body preparing step S1, a first closing step S2, a second closing step S3, a cutting step S4, and a third closing step S5. However, the order of the first closing step S2 and the second closing step S3 is not limited to the above. The second closing step S3 may be performed before the first closing step S2 or may be performed simultaneously with the first closing step S2.

[0049] 6A to 6D are schematic diagrams showing the process from the cylindrical body preparation step to the cutting step in chronological order.

[0050] As shown in Fig. 6A, in the cylindrical body preparation step S1, a cylindrical body 10 is prepared. The cylindrical body 10 has a first open end 11 and a second open end 12 on either side in a first direction D1. Specifically, the cylindrical body 10 has a substantially rectangular cylindrical outer shape. That is, the first open end 11 and the second open end 12 have a substantially rectangular annular outer shape when viewed from the first direction D1.

[0051] The cylindrical body 10 has a pair of first peripheral wall portions 13 and a pair of second peripheral wall portions 14. The pair of first peripheral wall portions 13 face each other in a second direction D2. The second direction D2 is a direction perpendicular to the first direction D1. When viewed from the second direction D2, the first peripheral wall portions 13 have a rectangular outer shape with the first direction D1 as the longitudinal direction.

[0052] The pair of second circumferential wall portions 14 face each other in the third direction D3. The third direction D3 is a direction perpendicular to both the first direction D1 and the second direction D2. When viewed from the third direction, the second circumferential wall portion 14 has a rectangular outer shape with the first direction D1 as its longitudinal direction. The dimension of the second circumferential wall portion 14 in the second direction D2 is shorter than the dimension of the first circumferential wall portion 13 in the third direction D3. The dimension of the first circumferential wall portion 13 in the third direction D3 is shorter than the dimension of the tubular body 10 in the first direction D1 (the dimension of the first circumferential wall portion 13 and the second circumferential wall portion 14 in the first direction D1).

[0053] The cylindrical body 10 is made of a metal such as aluminum or an aluminum alloy. In this embodiment, the cylindrical body 10 is prepared by extrusion molding. As a specific method of extrusion molding, a conventionally known method can be used.

[0054] 6A and 6B, in the first closing step S2, the first opening end 11 is closed with a first plate-shaped member 20. Specifically, the first plate-shaped member 20 is joined to the first opening end 11 by welding such as laser welding. The first plate-shaped member 20 has a substantially rectangular outer shape when viewed from the first direction D1.

[0055] In the second closing step S3, the second opening end 12 is closed with the second plate-shaped member 30. Specifically, the second plate-shaped member 30 is joined to the second opening end 12 by welding such as laser welding. The second plate-shaped member 30 has a substantially rectangular outer shape when viewed from the first direction D1.

[0056] The first plate-shaped member 20 and the second plate-shaped member 30 are made of a metal such as aluminum or an aluminum alloy. The first plate-shaped member 20 and the second plate-shaped member 30 are preferably made of the same type of material as the material that forms the cylindrical body 10.

[0057] 6B to 6D, in the cutting step S4, with the first open end 11 closed by the first plate-shaped member 20 and the second open end 12 closed by the second plate-shaped member 30, the cylindrical body 10, the first plate-shaped member 20, and the second plate-shaped member 30 are cut along a plane parallel to the first direction D1. Specifically, this plane is a plane parallel to both the first direction D1 and the second direction D2.

[0058] As a result of the above-described cutting, the cylindrical body 10 is separated into two pieces in the third direction D3. Specifically, each of the pair of first peripheral wall portions 13 is separated into two pieces in the third direction D3. A pair of cut edges 10E are formed on each of the two separated cylindrical body 10 pieces. The pair of cut edges 10E extend in the first direction D1.

[0059] By the above-described cutting, the first plate-shaped member 20 is separated into two in the third direction D3. Specifically, a cut edge 20E is formed on each of the two separated first plate-shaped members 20. The cut edge 20E extends in the second direction D2.

[0060] By the above-described cutting, the second plate-shaped member 30 is separated into two pieces in the third direction D3. Specifically, a cut edge 30E is formed on each of the two separated second plate-shaped members 30. The cut edge 30E extends in the second direction D2.

[0061] Therefore, in the cutting step S4, a case main body 210 is obtained in which the cut edges 10E, 20E, 30E of the cylindrical body 10, the first plate-shaped member 20, and the second plate-shaped member 30 form openings OP. Specifically, by the above cutting, one of the pair of second peripheral wall portions 14 becomes the bottom portion 220. A portion of each of the pair of first peripheral wall portions 13 becomes the first side surface portion 231 and the second side surface portion 232. A portion of the first plate-shaped member 20 becomes the first end surface portion 241. A portion of the second plate-shaped member 30 becomes the second end surface portion 242.

[0062] Furthermore, in this embodiment, as shown in Figures 6C and 6D, multiple case bodies 210 can be obtained by obtaining a first case body 210A constituted by a portion of each of the cut tubular body 10, the first plate-shaped member 20, and the second plate-shaped member 30, and a second case body 210B constituted by another portion of each of the cut tubular body 10, the first plate-shaped member 20, and the second plate-shaped member 30.

[0063] Fig. 7 is a schematic diagram showing the third closing step S5. As shown in Fig. 7, in the third closing step S5, the opening OP of the case body 210 is closed with the lid portion 250. Specifically, the lid portion 250 is joined to the opening OP by welding such as laser welding.

[0064] The electrode body 100, external terminal 300, connecting member 400, and insulating member 500 are previously assembled to the lid portion 250. The lid portion 250 closes the opening OP, and the electrode body 100 and the like are housed inside the case body 210. At this time, no sealing member 274 is provided on the liquid pouring port h.

[0065] After the opening OP is closed with the lid portion 250, the electrolyte is poured through the pouring port h. After the electrolyte is poured, the pouring port h is sealed with a sealing member 274 (see FIG. 1). In this manner, the battery case 200 according to this embodiment is manufactured. Furthermore, the storage cell 1 is manufactured at the same time as the battery case 200 is manufactured.

[0066] As described above, the manufacturing method of a battery case according to one embodiment of the present disclosure is a manufacturing method of a battery case 200 that can accommodate an electrode body 100 and has a bottomed cylindrical case body 210 having a bottom 220 and an opening OP located opposite the bottom 220, and a lid 250 that closes the opening OP. The manufacturing method includes preparing a tubular body 10 having a first opening end 11 and a second opening end 12 on either side in a first direction D1 (S1); closing the first opening end 11 with a first plate-shaped member 20 (S2); closing the second opening end 12 with a second plate-shaped member 30 (S3); cutting the tubular body 10, the first plate-shaped member 20, and the second plate-shaped member 30 along a plane parallel to the first direction D1 while the first opening end 11 is closed by the first plate-shaped member 20 and the second opening end 12 is closed by the second plate-shaped member 30 to obtain a case body 210 having openings OP at the cut edges 10E, 20E, 30E of the tubular body 10, the first plate-shaped member 20, and the second plate-shaped member 30 (S4); and closing the opening OP of the case body 210 with a lid portion 250 (S5).

[0067] According to the above configuration, the cylindrical body 10 having the first opening end 11 and the second opening end 12 on both sides can be prepared without relying on drawing. At this time, it is also possible to prepare a cylindrical body 10 that is relatively long in the first direction D1. Then, by cutting the cylindrical body 10, the first plate-shaped member 20, and the second plate-shaped member 30 along a plane parallel to the first direction D1, it is possible to easily obtain a case main body 210 having an opening OP that is relatively long in the first direction D1 (width direction W). In other words, according to the manufacturing method of the battery case according to this embodiment, it is possible to increase the degree of freedom in the dimension of the opening OP formed in the case main body 210 in the first direction D1 (width direction W).

[0068] In addition, in the manufacturing method of the battery case according to the embodiment of the present disclosure, the cylindrical body 10 is prepared by molding using extrusion molding.

[0069] According to the above configuration, by forming the cylindrical body 10 by extrusion molding, it becomes easier to prepare a cylindrical body 10 that is relatively long in the first direction D1.

[0070] Furthermore, in a method for manufacturing a battery case according to one embodiment of the present disclosure, a first case body 210A is formed from a portion of each of the cut cylindrical body 10, the first plate-shaped member 20, and the second plate-shaped member 30, and a second case body 210B is formed from another portion of each of the cut cylindrical body 10, the first plate-shaped member 20, and the second plate-shaped member 30, thereby obtaining a plurality of case bodies 210.

[0071] According to the above steps, excess material is prevented from being produced in the cutting step S4, and the yield of the case body 210 relative to the cylindrical body 10, the first plate-shaped member 20, and the second plate-shaped member 30 can be improved.

[0072] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims rather than the description of the above embodiments, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0073] 1 storage cell, 10 cylindrical body, 10E cutting edge, 11 first opening end, 12 second opening end, 13 first peripheral wall portion, 14 second peripheral wall portion, 20 first plate-shaped member, 20E cutting edge, 30 second plate-shaped member, 30E cutting edge, 100 electrode body, 110 positive electrode, 112 positive electrode current collector foil, 112p positive electrode tab, 114 positive electrode active material layer, 120 negative electrode, 122 negative electrode current collector foil, 122n negative electrode tab, 124 negative electrode active material layer, 130 separator, 132a interposition portion, 132b upper folded portion, 132c lower folded portion, 132d outermost coating portion, 132e termination, 150 insulating film, 200 battery case, 210 case body, 210A First case body, 210B second case body, 220 bottom, 221 long side portion, 222 short side portion, 231 first side portion, 232 second side portion, 241, 241a first end portion, 242, 242a second end portion, 250 lid portion, 272, 272a pressure release valve, 274, 274a sealing member, 300 external terminal, 400 connecting member, 410 current collecting tab, 412 side portion, 414 upper portion, 420 sub-tab, 422 one end portion, 424 other end portion, 430 connecting pin, 500 insulating member, 510 upper insulating portion, 520 insulating portion, 530 insulating tube, 540 insulating plate, OP opening, h liquid filling port.

Claims

1. A method for manufacturing a battery case comprising: a cylindrical case body having a bottom and a lid that closes the opening and that can accommodate an electrode assembly and has a bottom and an opening located opposite the bottom, the method comprising: preparing a cylindrical body having a first open end and a second open end on both sides in one direction; closing the first open end with a first plate-like member; closing the second open end with a second plate-like member; with the first opening end closed by the first plate-like member and the second opening end closed by the second plate-like member, cutting the cylindrical body, the first plate-like member, and the second plate-like member along a plane parallel to the one direction to obtain the case main body, with the cut edges of the cylindrical body, the first plate-like member, and the second plate-like member as the openings; and sealing the opening of the case body with the lid portion.

2. The method for manufacturing a battery case according to claim 1 , wherein the cylindrical body is prepared by extrusion molding.

3. 3. The method for manufacturing a battery case according to claim 1 or claim 2, wherein a plurality of the case bodies are obtained by obtaining a first case body constituted by a portion of each of the cut cylindrical body, the first plate-like member, and the second plate-like member, and a second case body constituted by another portion of each of the cut cylindrical body, the first plate-like member, and the second plate-like member.

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