Manufacturing method of battery shell

Abstract

Provided is a method for manufacturing a battery case, comprising the steps of: preparing a cylindrical body having a first open end and a second open end on both sides in a first direction, respectively; the first open end is closed through a first plate-shaped component; the second open end is closed through a second plate-shaped component; cutting the cylindrical body, the first plate-like member, and the second plate-like member along a plane parallel to the first direction in a state in which the first open end is closed by the first plate-like member and the second open end is closed by the second plate-like member, thereby obtaining a housing main body having the cut edges of the cylindrical body, the first plate-like member, and the second plate-like member as openings; the opening of the housing main body is closed by a cover portion.

Description

Technical Field

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

[0002] Japanese Patent Gazette No. 2021-158014 discloses a method for manufacturing a battery case in which a sealing plate is integrally installed on the opening of a shell body with a bottomed cylindrical shape. In this manufacturing method, a pre-prepared blank is subjected to drawing and thinning to form an intermediate product with a bottom having an elliptical or oblong cross-sectional shape. In addition, the intermediate product is further subjected to multiple drawing or thinning processes to gradually reduce the radius of curvature of the four corners in such a way that the cross-sectional shape becomes rectangular, and the wall thickness of the side wall portion forming the above-mentioned corners is reduced to form the final product as the above-mentioned shell body. Summary of the invention

[0003] In order to further reduce the height of the storage unit, it is required that the battery case be further lengthened in a direction orthogonal to the opening direction of the case body. However, in the deep drawing process disclosed in Japanese Patent Publication No. 2021-158014, it is difficult to form an opening with a longer dimension in the above-mentioned direction. Therefore, in the previous manufacturing method of the battery case, the size of the opening in the above-mentioned direction is restricted.

[0004] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide a method for manufacturing a battery case that can increase the degree of freedom of the dimension in one direction of an opening formed in a case body.

[0005] The manufacturing method of the battery shell based on the present disclosure is a manufacturing method of the battery shell that can accommodate an electrode body and has a shell body with a bottom and a cover, wherein the shell body has a bottom and an opening located at the opposite position of the bottom, and the cover closes the opening. The manufacturing method includes the following steps: 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; in a state where the first opening end is closed by the first plate-shaped member and the second opening end is closed by the second plate-shaped member, cutting the cylindrical body, the first plate-shaped member, and the second plate-shaped member along a surface parallel to one direction, thereby obtaining a shell body with the cut edges of the cylindrical body, the first plate-shaped member, and the second plate-shaped member as an opening; and closing the opening of the shell body with the cover.

[0006] According to the above structure, a cylindrical body having a first open end and a second open end on both sides can be prepared without relying on drawing. At this time, a cylindrical body that is relatively long in the above one direction can also be prepared. In addition, by cutting the cylindrical body, the first plate-shaped member and the second plate-shaped member along a surface parallel to the above one direction, a shell body having an opening that is relatively long in the above one direction can be easily obtained. That is, according to the manufacturing method of the battery shell based on the present disclosure, the degree of freedom of the size of the opening formed in the shell body in the above one direction can be increased.

[0007] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a perspective view showing a power storage unit according to one embodiment of the present disclosure.

[0009] Figure 2 Observe in the direction of the arrow on line II-II Figure 1 A cross-sectional view of a power storage unit.

[0010] Figure 3 Observe from the direction of the arrow on line III-III Figure 2 A cross-sectional view of an electrode body.

[0011] Figure 4 It is a perspective view showing a power storage unit according to a modification of the present disclosure.

[0012] Figure 5 1 is a flowchart showing a method for manufacturing a battery case according to an embodiment of the present disclosure.

[0013] FIG. 6A to FIG. 6D This is a schematic diagram showing the process from the tubular body preparation process to the cutting process in time series.

[0014] Figure 7 It is a schematic diagram which shows the state of the third sealing process. DETAILED DESCRIPTION

[0015] The embodiments of the present disclosure are described with reference to the accompanying drawings. In the drawings referred to below, the same or corresponding components are denoted by the same reference numerals.

[0016] [Power storage unit] First, a power storage unit according to an embodiment of the present disclosure will be described. The power storage unit includes a battery case manufactured by the method for manufacturing a battery case according to an embodiment of the present disclosure. Figure 1 It is a perspective view showing a power storage unit according to one embodiment of the present disclosure. Figure 2 Observe in the direction of the arrow on line II-II Figure 1 A cross-sectional view of a power storage unit.

[0017] like Figure 1 and Figure 2 As shown, the power storage cell 1 includes an electrode body 100 , a battery case 200 , a pair of external terminals 300 , a pair of connecting members 400 , and an insulating member 500 .

[0018] Figure 3 Observe from the direction of the arrow on line III-III Figure 2 A cross-sectional view of the electrode body. Figure 3 As shown, the electrode body 100 includes a plurality of electrodes 110 and 120 and a separator 130 .

[0019] like Figure 3 As shown, the plurality of electrodes 110 and 120 are arranged in a row in the thickness direction T. In the present embodiment, the thickness direction T is orthogonal to the height direction H. The plurality of electrodes 110 and 120 include a plurality of positive electrodes 110 and a plurality of negative electrodes 120 .

[0020] Each positive electrode 110 is formed into 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 includes a positive electrode collector foil 112 and a positive electrode active material layer 114 provided on both sides of the positive electrode collector foil 112. The positive electrode collector foil 112 includes a positive electrode tab 112p (see Figure 2 ). The positive electrode tab 112p protrudes toward one side in the width direction W.

[0021] Each negative electrode 120 is formed in a rectangular shape that is long in the width direction. Each negative electrode 120 includes 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. Figure 2 As shown, the negative electrode current collector foil 122 has a negative electrode tab 122n without a negative electrode active material layer 124 (see Figure 2 ). The negative electrode tab 122n protrudes toward the other side in the width direction.

[0022] The separator 130 insulates the positive electrode 110 from the negative electrode 120. The separator 130 is made of an insulating material and has tiny gaps that allow ions to pass through. Figure 3 As shown, the partition 130 is formed in a zigzag shape.

[0023] The separator 130 has a rectangular shape before being formed into a zigzag shape. The separator 130 is formed into a zigzag shape and arranged between the electrodes 110 and 120. 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.

[0024] Each intervening portion 132a is interposed between a pair of electrodes 110 and 120 adjacent to each other in one direction. That is, each intervening portion 132a has a function of insulating the positive electrode 110 from the negative electrode 120. Each intervening portion 132a is composed of a rectangular region.

[0025] Each upper folded portion 132b connects the upper end of one of the plurality of clamping portions 132a and the upper end of a clamping portion 132a adjacent to the one clamping portion 132a on one side in one direction. In the present embodiment, the upper folded portion 132b is disposed above the positive electrode 110.

[0026] Each lower folded portion 132c connects the lower end of one of the plurality of clamping portions 132a and the lower end of the clamping portion 132a adjacent to the one of the plurality of clamping portions 132a on the other side in one direction. In the present 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.

[0027] The outermost covering portion 132d covers all the upper folded portions 132b and all the lower folded portions 132c. In more detail, the outermost covering portion 132d winds all the electrodes 110, 120, all the clamping portions 132a, all the upper folded portions 132b and all the lower folded portions 132c around a central axis parallel to the width direction and covers them together. The terminal 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 the present embodiment, the terminal end 132e of the outermost covering portion 132d is provided below each electrode 110, 120. In addition, the peripheral surface and bottom surface of the plurality of electrodes 110, 120 and the separator 130 are covered with an insulating film 150 (refer to the later-described Figure 7 ,exist Figure 2 as well as Figure 3 (not shown in the figure).

[0028] like Figure 1 and Figure 2 As shown, the electrode body 100 is housed in the battery case 200. An electrolyte solution (not shown) is housed in the battery case 200. The battery case 200 is sealed. The battery case 200 is made of metal such as aluminum or an aluminum alloy.

[0029] The battery case 200 has a bottomed cylindrical shape and includes a case body 210 and a cover 250 . The case body includes a bottom 220 , a first side surface 231 , a second side surface 232 , a first end surface 241 , and a second end surface 242 .

[0030] 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.

[0031] The bottom portion 220 has a pair of long sides 221 and a pair of short sides 222 . The long sides 221 extend in the width direction W. The short sides 222 extend in 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 .

[0032] The first side surface portion 231 stands from the bottom portion 220. The direction in which the first side surface portion 231 stands is the height direction H. Specifically, the first side surface portion 231 stands from one of the pair of long sides 221. In the present embodiment, the first side surface portion 231 and the bottom portion 220 are integrally formed without being welded.

[0033] The second side surface portion 232 faces the first side surface portion 231 and rises from the bottom portion 220. Therefore, the direction in which the second side surface portion 232 rises is also the height direction H. Specifically, the second side surface portion 232 rises from the other of the pair of long sides 221. In the present embodiment, the second side surface portion 232 and the bottom portion 220 are not welded but are formed integrally.

[0034] The first end surface 241 is welded to one of the pair of short sides 222 of the bottom 220. The first end surface 241 extends from one of the pair of short sides 222 in the height direction H. The first end surface 241 is welded to both the first side surface 231 and the second side surface 232.

[0035] The second end surface 242 is welded to the other of the pair of short sides 222 of the bottom 220. The first end surface 241 extends from the other of the pair of short sides 222 in the height direction H. The first end surface 241 is welded to both the first side surface 231 and the second side surface 232.

[0036] The housing body 210 has an opening OP located on the opposite side of the bottom 220 . The opening OP is formed by the end edges of the first side surface portion 231 , the second side surface portion 232 , the first end surface portion 241 , and the second end surface portion 242 located on the opposite side of the bottom 220 .

[0037] The cover 250 closes the opening OP. The cover 250 is connected to the opening OP by welding or the like. The cover 250 is formed in a flat plate shape.

[0038] The cover 250 includes a pressure release valve 272 and a sealing member 274. The pressure release valve 272 is formed in the central portion of the cover 250. The pressure release valve 272 is formed to rupture when the internal pressure of the battery case 200 is greater than a predetermined pressure. When the pressure release valve 272 ruptures, the gas in the battery case 200 is released to the outside of the battery case 200 through the pressure release valve 272, so that the internal pressure of the battery case 200 is reduced.

[0039] The sealing member 274 seals the injection port h formed in the lid 250 . The injection port h is a through hole for injecting electrolyte into the battery case 200 during the manufacturing process of the power storage unit 1 . After the electrolyte is injected into the battery case 200 through the injection port h, the injection port h is sealed by the sealing member 274 .

[0040] In addition, the pressure release valve 272 and the sealing member 274 may be arranged at a position different from the cover portion 250 . Figure 4 1 is a perspective view showing a storage unit according to a modified example of the present disclosure. Figure 4 As shown, the first end surface portion 241a may also include a pressure release valve 272a and a sealing member 274a. The second end surface portion 242a may also include a pressure release valve 272a and a sealing member 274a.

[0041] like Figure 1 and Figure 2 As shown, a pair of external terminals 300 are fixed to the battery case 200. One of the pair of external terminals 300 is the external terminal of the positive electrode, and the other is the external terminal of the negative electrode. Each external terminal 300 is fixed to the upper surface of the cover 250 via an upper insulating portion 510 described later. Each external terminal 300 is made of metal such as aluminum.

[0042] A pair of connecting members 400 connects the plurality of electrode tabs 112p and 122n to the external terminal 300. One connecting member 400 connects the plurality of positive electrode tabs 112p to the positive external terminal 300, and the other connecting member 400 connects the plurality of negative electrode tabs 122n to the negative external terminal 300. The pair of connecting members 400 each have substantially the same structure, so one connecting member 400 will be described below.

[0043] The connecting member 400 includes a current collector tab 410 , a secondary tab 420 , and a connecting pin 430 .

[0044] The current collector tab 410 has a side portion 412 and an upper portion 414. The side portion 412 is located on the side of the electrode body 100 in the width direction. The upper portion 414 is located above the electrode body 100. The upper portion 414 extends from the upper end of the side portion 412 toward the inner side in the width direction.

[0045] The auxiliary tab 420 connects the plurality of positive tabs 112p to the collector tab 410. One end 422 of the auxiliary tab 420 is connected to the plurality of positive tabs 112p by welding or the like, and the other end 424 of the auxiliary tab 420 is connected to the side portion 412 of the collector tab 410 by welding or the like.

[0046] The connecting pin 430 connects the collector tab 410 to the external terminal 300. The connecting pin 430 connects the upper portion 414 to the external terminal 300. Specifically, the lower end of the connecting pin 430 is connected to the upper portion 414 by welding or the like while being inserted into a through hole provided in the upper portion 414, and the upper end of the connecting pin 430 is connected to the external terminal 300 by welding, riveting or the like while being inserted into a through hole provided in the external terminal 300.

[0047] The insulating member 500 insulates the battery case 200 from the connecting member 400. The insulating member 500 includes an upper insulating portion 510, a lower insulating portion 520, an insulating tube 530, and an insulating plate 540.

[0048] The upper insulating portion 510 is fixed to the upper surface of the cover portion 250. The upper insulating portion 510 is disposed between the cover portion 250 and the external terminal 300. The upper insulating portion 510 is provided with an insertion hole through which the coupling pin 430 is inserted.

[0049] The lower insulating portion 520 is fixed to the lower surface of the cover portion 250. The lower insulating portion 520 is disposed between the cover portion 250 and the upper portion 414 and the lower portion of the connecting pin 430. The lower insulating portion 520 is provided with an insertion hole through which the connecting pin 430 is inserted.

[0050] The insulation tube 530 is disposed between the connection pin 430 and the cover portion 250. The insulation tube 530 is formed in a cylindrical shape and surrounds the connection pin 430.

[0051] The insulating plate 540 is fixed to the lower surface of the upper portion 414. The insulating plate 540 is disposed above the electrode body 100. Through holes are provided in the insulating plate 540 at a portion below the pressure release valve 272 and at a portion below the liquid injection port h.

[0052] In addition, 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 other conductive members may be arranged between the external terminal 300 and the battery case 200 instead of the upper insulating portion 510.

[0053] [Method for manufacturing battery case] Next, a method for manufacturing a battery case according to an embodiment of the present disclosure will be described. Figure 5 1 is a flow chart showing a method for manufacturing a battery case according to an embodiment of the present disclosure. Figure 5 As shown, a method for manufacturing a battery case according to an embodiment of the present disclosure includes a cylindrical body preparation step S1, a first sealing step S2, a second sealing step S3, a cutting step S4, and a third sealing step S5 in sequence. However, the order of the first sealing step S2 and the second sealing step S3 is not limited to the above order. The second sealing step S3 can be implemented before the first sealing step S2, or it can be implemented simultaneously with the first sealing step S2.

[0054] Figure 6A to Figure 6D This is a schematic diagram showing the process from the tubular body preparation process to the cutting process in time series.

[0055] like Fig. 6A As shown, 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 both sides in the first direction D1. Specifically, the cylindrical body 10 has a generally rectangular cylindrical shape. That is, when viewed from the first direction D1, the first open end 11 and the second open end 12 have a generally rectangular ring shape.

[0056] 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 the second direction D2. The second direction D2 is a direction orthogonal to the first direction D1. When viewed from the second direction D2, the first peripheral wall portion 13 has a rectangular shape with the first direction D1 as the long side direction.

[0057] A pair of second peripheral wall portions 14 face each other in the third direction D3. The third direction D3 is a direction orthogonal to both the first direction D1 and the second direction D2. The second peripheral wall portion 14 has a rectangular shape with the first direction D1 being the long side direction when viewed from the third direction. In addition, the dimension of the second peripheral wall portion 14 in the second direction D2 is shorter than the dimension of the first peripheral wall portion 13 in the third direction D3. The dimension of the first peripheral 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 peripheral wall portion 13 and the second peripheral wall portion 14 in the first direction D1).

[0058] The cylindrical body 10 is made of metal such as aluminum or an aluminum alloy, for example. In the present embodiment, the cylindrical body 10 is prepared by extrusion molding. As a specific method of extrusion molding, a conventionally known method can be adopted.

[0059] like Fig. 6A and Figure 6B As shown, in the first closing step S2, the first open end 11 is closed by the first plate-shaped member 20. Specifically, the first plate-shaped member 20 is welded to the first open end 11 by laser welding or the like. The first plate-shaped member 20 has a substantially rectangular outer shape when viewed from the first direction D1.

[0060] In the second closing step S3, the second open end 12 is closed by the second plate-shaped member 30. Specifically, the second plate-shaped member 30 is welded to the second open end 12 by laser welding or the like. The second plate-shaped member 30 has a substantially rectangular outer shape when viewed from the first direction D1.

[0061] The first plate member 20 and the second plate member 30 are made of metal such as aluminum or an aluminum alloy. The first plate member 20 and the second plate member 30 are preferably made of the same material as the material forming the cylindrical body 10 .

[0062] like Figure 6B to Figure 6D As shown, in the cutting process S4, 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 in a state where 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. Specifically, the plane is parallel to both the first direction D1 and the second direction D2.

[0063] By the above-mentioned cutting, the cylindrical body 10 is separated into two in the third direction D3. Specifically, the pair of first peripheral wall portions 13 are separated into two in the third direction D3. A pair of cutting edges 10E are formed on each of the two separated cylindrical bodies 10. The pair of cutting edges 10E extend along the first direction D1.

[0064] By the above-mentioned 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 along the second direction D2.

[0065] By the above-mentioned cutting, the second plate-shaped member 30 is separated into two 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 along the second direction D2.

[0066] Therefore, in the cutting process S4, the housing 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 are used as the opening OP. Specifically, through the above-mentioned cutting, one of the pair of second peripheral wall portions 14 becomes the bottom 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.

[0067] In addition, in this embodiment, if Figure 6C and Fig.6D As shown, a plurality of shell bodies 210 can be obtained by obtaining a first shell body 210A composed of a portion of the cut cylindrical body 10, the first plate-shaped part 20 and the second plate-shaped part 30 and a second shell body 210B composed of another portion of the cut cylindrical body 10, the first plate-shaped part 20 and the second plate-shaped part 30.

[0068] Figure 7 Schematic diagram showing the third sealing process. Figure 7 As shown, in the third closing step S5, the opening OP of the case body 210 is closed by the cover 250. Specifically, the cover 250 is joined to the opening OP by welding such as laser welding.

[0069] The electrode body 100, the external terminal 300, the connecting member 400, and the insulating member 500 are pre-assembled in the lid 250. The lid 250 closes the opening OP and accommodates the electrode body 100 and the like in the case body 210. In this case, the sealing member 274 is not provided at the liquid injection port h.

[0070] After the opening OP is closed by the cover 250, the electrolyte is injected from the injection port h. After the electrolyte is injected, the injection port h is sealed by the sealing member 274 (see Figure 1 ). In this way, the battery case 200 according to the present embodiment is manufactured. In addition, the battery case 200 is manufactured and the power storage unit 1 is manufactured.

[0071] As described above, a method for manufacturing a battery case according to one embodiment of the present disclosure is a method for manufacturing a battery case 200 that can accommodate an electrode body 100 and has a bottomed cylindrical case body 210 and a cover 250, wherein the case body 210 has a bottom 220 and an opening OP located on the opposite side of the bottom 220, and the cover 250 closes the opening OP. The manufacturing method comprises the following steps: preparing a cylindrical body 10 having a first opening end 11 and a second opening end 12 on both sides in a first direction D1 (S1); closing the first opening end 11 by using a first plate-shaped member 20 (S2); closing the second opening end 12 by using a second plate-shaped member 30 (S3); in a state where 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, 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, thereby obtaining a shell body 210 having cut edges 10E, 20E, 30E of the cylindrical body 10, the first plate-shaped member 20 and the second plate-shaped member 30 as an opening OP (S4); and closing the opening OP of the shell body 210 by using a cover portion 250 (S5).

[0072] According to the above structure, the cylindrical body 10 having the first open end 11 and the second open end 12 on both sides can be prepared without relying on drawing. At this time, a cylindrical body 10 that is relatively long in the first direction D1 can also be prepared. In addition, by cutting the cylindrical body 10, the first plate-shaped member 20 and the second plate-shaped member 30 along a surface parallel to the first direction D1, it is possible to easily obtain a shell body 210 having an opening OP that is relatively long in the first direction D1 (width direction W). That is, according to the manufacturing method of the battery shell involved in this embodiment, the degree of freedom of the size of the opening OP formed in the shell body 210 in the first direction D1 (width direction W) can be increased.

[0073] In addition, in the method for manufacturing a battery case according to one embodiment of the present disclosure, the cylindrical body 10 is prepared by molding the cylindrical body 10 by extrusion molding.

[0074] According to the above-mentioned structure, the cylindrical body 10 is formed by extrusion molding, so that it is easier to prepare the cylindrical body 10 which is relatively long in the first direction D1.

[0075] In addition, in a method for manufacturing a battery case according to an embodiment of the present disclosure, a plurality of case bodies 210 are obtained by obtaining a first case body 210A formed by a portion of each of the cut cylindrical body 10, the first plate-shaped part 20 and the second plate-shaped part 30, and a second case body 210B formed by another portion of each of the cut cylindrical body 10, the first plate-shaped part 20 and the second plate-shaped part 30.

[0076] According to the above-described steps, it is possible to suppress the surplus of components in the cutting step S4 , and to improve the yield rate of the case body 210 with respect to the cylindrical body 10 , the first plate-shaped member 20 , and the second plate-shaped member 30 .

[0077] Although the embodiments of the present invention have been described, the embodiments disclosed this time should be considered to be illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims, and it is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A method for manufacturing a battery case, wherein the battery case is capable of accommodating an electrode body and comprises a bottomed cylindrical case body and a cover, wherein the case body has a bottom and an opening located on the opposite side of the bottom, and the cover closes the opening, The manufacturing method of the battery case comprises the following steps: 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-shaped member; closing the second open end with a second plate-shaped member; In a state where the first opening end is closed by the first plate-shaped member and the second opening end is closed by the second plate-shaped member, the cylindrical body, the first plate-shaped member and the second plate-shaped member are cut along a plane parallel to the one direction, thereby obtaining the shell body having the cut edges of the cylindrical body, the first plate-shaped member and the second plate-shaped member as the opening; and The opening of the housing body is closed by the cover.

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

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

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