Sealed can body, battery, method for manufacturing sealed can body, and method for manufacturing battery

Abstract

The sealed can body according to one embodiment of the present disclosure is provided with a body and a lid. The body is a single bent metal plate. The body comprises: a bottom surface which is continuous with one short side of the lid, the long sides of the bottom surface being along the lid in the vertical direction; two long wall surfaces which are continuous with the long sides of the lid, the long sides of the long wall surfaces being along the lid in the vertical direction; a short wall surface which faces the lid; and one top surface which is continuous with the other short side of the lid, the long sides of the top surface being along the lid in the vertical direction. The bottom surface and the two long wall surfaces are continuous with each other via a bent portion of the metal plate. The top surface and the two long wall surfaces are continuous with each other via a bent portion of the metal plate. A first welded portion extending from the lid body to the short wall surface is present inside the top surface. A second welded portion extending from the top surface to the bottom surface is present on the short wall surface. The top surface and the short wall surface are continuous with each other via a third welded portion extending from one of the long wall surfaces to the other long wall surface.

Description

Sealed can body, battery, method for manufacturing a sealed can body, and method for manufacturing a battery

[0001] The present disclosure relates to a sealed can body, a battery, a method for manufacturing a sealed can body, and a method for manufacturing a battery. This application claims priority based on Japanese Patent Application No. 2024-157509 filed in Japan on September 11, 2024, the content of which is incorporated herein by reference.

[0002] In recent years, motor vehicles that use electric power as one of their driving sources, such as hybrid vehicles and electric vehicles, have attracted attention. As a power source for such motor vehicles, secondary batteries with high energy capacity have been put into practical use. Examples of storage batteries with high energy capacity include lithium-ion batteries.

[0003] For secondary batteries mounted in motor vehicles such as automobiles, a structure is adopted in which a power generation element and a current collector are housed in a rectangular housing. The housing of a secondary battery for automobiles is composed of a metal plate or the like and has high rigidity.

[0004] In recent years, lithium iron phosphate-based lithium-ion batteries have begun to be applied to secondary batteries for automobiles. One of the advantages of lithium iron phosphate-based lithium-ion batteries is that thermal runaway is less likely to occur and they have high safety. Another advantage of lithium iron phosphate-based lithium-ion batteries is that they are inexpensive. On the other hand, lithium iron phosphate-based lithium-ion batteries have the drawback of having a low energy density. Therefore, in order to use lithium iron phosphate-based lithium-ion batteries as secondary batteries for automobiles, it has been studied to increase the packing density and improve the storage capacity per unit volume.

[0005] An example of a secondary battery with a high packing density is a blade battery. An example of a battery that can be used as a blade battery is shown in FIG. 1. The blade battery includes a sealed can body 1 having a substantially rectangular parallelepiped shape housing. The sealed can body 1 has, for example, a body 11 and a lid body 12. The body 11 has a substantially rectangular parallelepiped shape with all six faces being substantially rectangular, and one face is an opening. The lid body 12 seals the opening of the body 11. In the present disclosure, the vertical direction of the lid body 12 is referred to as the longitudinal direction X. The direction parallel to the short side of the lid body 12 is referred to as the thickness direction Y. The direction parallel to the long side of the lid is referred to as the height direction Z.

[0006] The casing of the blade battery is flat. That is, the dimension b along the thickness direction Y of the blade battery is very small compared to the dimension a along the length direction X and the dimension c along the height direction Z. By using the blade battery as a battery cell and stacking multiple blade batteries along the thickness direction Y, it is possible to construct a battery unit with a high loading density.

[0007] Furthermore, the height Z of the blade battery constrains the thickness of the vehicle's floor. This is because the blade battery is installed inside the vehicle's floor with its height Z oriented vertically. Therefore, in the sealed casing of the blade battery, the dimension c along the height Z is smaller than the dimension a along the longitudinal X.

[0008] Furthermore, it is preferable that the electrodes 21 of the blade battery are provided on the lid 12 of the sealed can body 1. When such a blade battery is installed in a vehicle, the electrodes 21 are located on the side of the vehicle. Such a blade battery is sometimes referred to as a side-terminal battery. By using a side-terminal battery as the secondary battery of a vehicle, the thickness of the vehicle's floor can be reduced, resulting in a lower floor for the vehicle.

[0009] The aforementioned horizontal terminal type blade battery contributes to lowering the floor of automobiles and improving the battery unit loading density. However, it is difficult to manufacture the body of such a blade battery by deep drawing. Therefore, the body of the blade battery is manufactured by bending a metal plate into a roughly rectangular parallelepiped and then welding the ends of the metal plate.

[0010] Examples of techniques for manufacturing battery cases by welding the edges of bent metal plates are disclosed in Patent Documents 1 to 7.

[0011] Japanese Patent Publication No. 6142466, Japanese Unexamined Patent Publication No. 2014-059954, Japanese Unexamined Patent Publication No. Hei 6-333541, Japanese Unexamined Patent Publication No. 2002-198011, Japanese Unexamined Patent Publication No. 2012-133913, Japanese Unexamined Patent Publication No. 2009-004361, Japanese Unexamined Patent Publication No. 2001-236929

[0012] Recently, there has been a demand for lighter rechargeable batteries for automobiles. To meet this demand, attempts have been made to use aluminum for the casing material and to reduce the wall thickness of the casing. However, it is believed that such weight reduction methods make it difficult to ensure the structural strength acceptable for rechargeable batteries installed in moving vehicles.

[0013] Furthermore, when sealing cans are manufactured by deep drawing, variations in the wall thickness of the cans become significant. If the overall wall thickness of the cans is reduced, areas with excessively thin walls will occur. This makes it difficult to ensure the structural strength of the cans.

[0014] On the other hand, when a sealed casing is manufactured by bending a single metal sheet and welding its ends, thermal distortion occurs in the casing. This thermal distortion creates gaps between the stacked battery cells, reducing the battery unit's loading density. In particular, with long, plate-shaped blade batteries, the welded portion of the casing becomes longer, and the amount of thermal distortion increases.

[0015] In view of the above circumstances, the present disclosure aims to provide a sealed can body, a battery, a method for manufacturing a sealed can body, and a method for manufacturing a battery, which have the structural strength necessary for the housing of a rectangular secondary battery, particularly a battery with lateral terminals, are lightweight, have low thermal distortion, and have high production efficiency.

[0016] The gist of this disclosure is as follows:

[0017] (1) A sealed container according to one aspect of the present disclosure comprises a body having a rectangular parallelepiped shape with all six sides being rectangular and one side being an opening, and a lid that seals the opening, wherein the body is a single bent metal plate, and the body has a bottom surface that is connected to one of the short sides of the lid and whose long side is aligned with the vertical direction of the lid, two long wall surfaces that are connected to the long side of the lid and whose long sides are aligned with the vertical direction of the lid, a short wall surface that is opposite to the lid, and a short wall surface that is connected to the other short side of the lid, (1) Preferably, in the sealed can body described in (1) above, the bottom surface and the two long wall surfaces are connected via a bent portion of the metal plate, the top surface and the two long wall surfaces are connected via a bent portion of the metal plate, a first weld is present inside the top surface extending from the lid to the short wall surface, a second weld is present on the short wall surface extending from the top surface to the bottom surface, and the top surface and the short wall surface are connected via a third weld extending from one long wall surface to the other long wall surface. (2) Preferably, in the sealed can body described in (1) above, the bottom surface and the short wall surface are connected via a fourth weld. (3) Preferably, in the sealed can body described in (2) above, the second weld and the fourth weld are connected at the end of the fourth weld. (4) Preferably, in the sealed can body described in any one of (1) to (3) above, the second weld has a second A weld that extends from one end to the other of the boundary between the short wall surface and the bottom surface, is located inside the short wall surface and is bent, and a second B weld that extends from the boundary between the top surface and the short wall surface to the second A weld, and the bottom surface and the short wall surface are connected via the bent portion of the metal plate. (5) Preferably, in the sealed can body described in any one of (1) to (4) above, the short wall surface and the two long wall surfaces are connected via the bent portion of the metal plate. (6) Preferably, in the sealed can body described in any one of (1) to (5) above, the first weld is located in the center of the top surface. (7) Preferably, in the sealed can body described in any one of (1) to (6) above, the first weld and the second weld are separated.(8) Preferably, in the sealed can body described in (7) above, the end of the first weld and one end of the third weld are connected, and the end of the second weld and the other end of the third weld are connected. (9) Preferably, the sealed can body described in any one of (1) to (8) above is a battery case. (10) Preferably, in the sealed can body described in any one of (1) to (9) above, the second weld is provided inside the short wall surface. (11) Preferably, in the sealed can body described in any one of (1) to (10) above, the metal plate is a Ni-plated steel plate, a stainless steel plate, or an aluminum alloy plate.

[0018] (12) A battery according to another aspect of the present disclosure comprises a battery case, wherein the battery case is a sealed container as described in any one of paragraphs (1) to (11) above.

[0019] (13) A method for manufacturing a sealed can according to another aspect of the present disclosure is a method for manufacturing a sealed can including a lid and a body, comprising the steps of: manufacturing a material metal sheet; bending one of the material metal sheets to form a rectangular parallelepiped shape; and welding the portions of the material metal sheets that are butted together or overlapped in the bending step, wherein the material metal sheet has a rectangular bottom region and two identical long wall regions, each having a rectangular shape and positioned on both long sides of the bottom region, with the dimensions of the long sides of the long wall regions being the same as the dimensions of the long sides of the bottom region, and The dimensions of the short side of the long wall region are greater than the dimensions of the short side of the base region, and the long side of the base region and the long side of the long wall region are in contact with each other with their ends aligned. The long wall region and the first top region are located on the long side of one of the long wall regions opposite to the base region, and the dimensions of the long side of the first top region are the same as the dimensions of the long side of the base region, and the long side of the base region and the long wall region are in contact with each other with their ends aligned. The second top region are located on the long side of the other long wall region opposite to the base region. The second top surface area has the same dimension as the long side of the bottom surface area, and the long side of the bottom surface area and the long side of the long wall surface area are in contact with each other with their ends aligned. The first short wall surface area is located on one of the short sides of one of the long wall surface areas, and the dimension of the long side of the first short wall surface area is the same dimension as the short side of the long wall surface area, and the short side of one of the long wall surface areas and the long side of the first short wall surface area are in contact with each other with their ends aligned. The second short wall surface area is located on the other of the long wall surface areas, and the first short wall surface area is located on one of the short sides of one of the long wall surface areas. The first top region and the second top region have a shape obtained by dividing the bottom region into two parts, and the first short wall region and the second short wall region have a shape obtained by dividing a rectangular shape into two parts, where the dimension of the long side is the same as the dimension of the short side of the long wall region and the dimension of the short side is the same as the dimension of the short side of the bottom region.In the bending process, the end on the long side of the first top surface region and the end on the long side of the second top surface region are butted together or overlapped, and in the welding process, the end on the long side of the first top surface region and the end on the long side of the second top surface region are welded together to form the first welded part and the top surface, and in the bending process, the end on the long side of the first short wall surface region and the end on the long side of the second short wall surface region are butted together or overlapped, and in the welding process, the end on the long side of the first short wall surface region and the second short wall surface The ends on the longer sides of the region are welded together to form a second weld and a short wall. In the bending process, the ends on the shorter sides of the rectangular region formed by the first top surface region and the second top surface region are butted together or overlapped with the ends on the shorter sides of the rectangular region formed by the first short wall region and the second short wall region. In the welding process, the ends on the shorter sides of the rectangular region formed by the first top surface region and the second top surface region are welded together with the ends on the shorter sides of the rectangular region formed by the first short wall region and the second short wall region to form a third weld. (14) Preferably, in the method for manufacturing a sealed can described in (13) above, in the bending step, the ends on the short sides of the first short wall region and the rectangular region formed by the first short wall region and the ends on the short sides of the bottom region are butted together or overlapped, and in the welding step, the ends on the short sides of the first short wall region and the rectangular region formed by the first short wall region and the ends on the short sides of the bottom region are welded together to form a fourth welded part. (15) Preferably, in the method for manufacturing a sealed can described in (14) above, the first short wall region and the second short wall region have a right-angled triangular shape, the dimensions of the short sides of the first short wall region and the second short wall region are the same as the dimensions of the short sides of the bottom region, the hypotenuse of the first short wall region and the hypotenuse of the second short wall region are parallel before the bending process, in the bending process the hypotenuse of the first short wall region and the hypotenuse of the second short wall region are butted together or overlapped, in the welding process the hypotenuse of the first short wall region and the hypotenuse of the second short wall region are welded together to form the second weld, and the second weld and the fourth weld areIt is provided by continuous welding. (16) Preferably, in the method for manufacturing a sealed can body described in any one of the above items (13) to (15), the material metal plate further has a third short wall region provided on the short side of the bottom region, the boundary between the third short wall region and the bottom region extends from one end to the other on the short side of the bottom region, in the bending step the boundary between the third short wall region and the bottom region is made into a bent portion, and the first short wall region and the second short wall region are aligned with the third short wall region A notch having a matching shape is provided, and in the bending step, the end of the third short wall region and the end of the notch are brought into a butt joint or overlapping state, and in the welding step, the end of the third short wall region and the end of the notch are welded together to form a second A weld, and in the welding step, the end on the long side of the first short wall region and the end on the long side of the second short wall region are welded together to form a second B weld. (17) Preferably, in the method for manufacturing a sealed can described in any of (13) to (16) above, both the first short wall region and the second short wall region are made into a rectangular shape of the same shape, and in the welding step, the end on the long side of the first top surface region and the end on the long side of the second top surface region are welded together at the center of the long sides of the two long wall regions to form the first weld. (18) Preferably, in the method for manufacturing a sealed can body described in any of (13) to (17) above, the first top surface region and the first short wall surface region are arranged to be in contact with the same long wall surface region, the dimension of the short side of the first top surface region on the side of the first short wall surface region is different from the dimension of the short side of the first short wall surface region on the side of the first top surface region, and the first welded part and the second welded part are separated in the welding process. (19) Preferably, in the method for manufacturing a sealed can body described in any of (13) to (18) above, the dimension of the short side of the second top surface region on the side of the first short wall surface region and the second short wall surface region is the same as the dimension of the short side of the bottom surface region, the dimension of the short side of the first short wall surface region or the second short wall surface region that is joined to the short side of the second top surface region on the side of the first short wall surface region and the second short wall surface region is the same as the dimension of the short side of the bottom surface region, and in the welding process,The end of the first weld is connected to one end of the third weld, and the end of the second weld is connected to the other end of the third weld. (20) Preferably, in the method for manufacturing a sealed can described in any of (13) to (19) above, the material metal plate has relief portions provided in the first top surface region and the second top surface region, and / or relief portions provided in the first short wall surface region and the second short wall surface region, and the relief portions provided in the first top surface region and the second top surface region have a shape that extends the first top surface region and the second top surface region along the long side direction of the first top surface region and the first top surface region. Furthermore, the relief portions provided in the first short wall region and the second short wall region have a shape that extends the first short wall region and the second short wall region along the long side direction of the first short wall region and the second short wall region, and in the welding process, the starting or ending point of welding for forming the first weld and / or the second weld is set inside the relief portion, and the method for manufacturing the sealed can body further comprises a step of cutting off the relief portion after the welding process. (21) Preferably, in the method for manufacturing the sealed can body described in any of (13) to (20) above, the sealed can body is a battery case.

[0020] (22) A method for manufacturing a battery according to another aspect of the present disclosure includes a method for manufacturing a sealed can described in any of (13) to (21) above.

[0021] According to this disclosure, it is possible to provide a sealed can body, a battery, a method for manufacturing a sealed can body, and a method for manufacturing a battery, which have the necessary structural strength for the housing of a rectangular secondary battery, especially a battery with lateral terminals, are lightweight, have low thermal distortion, and have high production efficiency.

[0022] This is a perspective view of a battery with horizontal terminals. This is a perspective view of an example of a sealed can body just before the lid is attached to the body. This is a plan view of the raw metal plate used as the material for the body in Figure 2. This is a perspective view of an example of a body in which the first weld, second weld, and third weld are connected at their ends. This is a perspective view of an example of a body in which a short wall and one long wall are connected via a second weld. This is a perspective view of an example of a body in which the second weld has a Y-shape. This is a perspective view of an example of a body in which the first weld and the second weld are separated. This is a perspective view of an example of a body in which the first weld, second weld, and third weld are connected at their ends. This is a plan view of the raw metal plate used as the material for the body in Figure 4. This is a plan view of the raw metal plate used as the material for the body in Figure 6. This is a plan view of the raw metal plate used as the material for the body in Figure 7. This is a plan view of the raw metal plate used as the material for the body in Figure 8. This is a plan view of a raw metal plate with a relief section. This is a perspective view of the body in Figure 13 immediately after the raw metal plate has been welded.

[0023] The sealed container, battery, method for manufacturing the sealed container, and method for manufacturing the battery related to this disclosure will be described in detail below. In this disclosure, "identical dimensions" means so-called "approximately identical dimensions." If the difference in dimensions is 0.4 mm or less, the dimensions of the two objects are considered to be identical. Preferably, if the difference in dimensions of the two objects is 0.2 mm or less, the dimensions of the two objects are considered to be identical. In this disclosure, "right angle" means so-called "approximately right angle." An angle of 88 degrees or more and 92 degrees or less is considered a right angle. In this disclosure, "rectangle" means so-called "approximately rectangular." Specifically, a shape in which the dimensions of opposite sides are "approximately identical" and the angle between adjacent sides is "approximately right angle" is considered a rectangle. In this disclosure, "cuboid" means so-called "approximately cuboid." A hexahedron in which all faces are "approximately rectangular" is considered a cuboid.

[0024] (1. Sealed Can Body) The sealed can body 1 according to this embodiment, as shown in Figures 1 and 2, etc., comprises a body 11 having a rectangular parallelepiped shape with all six sides being rectangular and one side being an opening 115, and a lid 12 that seals the opening 115, wherein the body 11 is a single bent metal plate, and the body 11 has a bottom surface 114 that is connected to one short side of the lid 12 and whose long side is aligned with the vertical direction of the lid 12, two long wall surfaces 113 that are connected to the long side of the lid 12 and whose long sides are aligned with the vertical direction of the lid 12, a short wall surface 112 that is opposite to the lid 12, and the other short side of the lid 12 The lid has a top surface 111 whose long side is aligned with the vertical direction of the lid 12, and the bottom surface 114 and two long wall surfaces 113 are connected via bent portions 130 of the metal plate, and the top surface 111 and the two long wall surfaces 113 are connected via bent portions 130 of the metal plate, and inside the top surface 111 there is a first welded portion 131 that extends from the lid 12 to the short wall surface 112, and on the short wall surface 112 there is a second welded portion 132 that extends from the top surface 111 to the bottom surface 114, and the top surface 111 and the short wall surface 112 are connected via a third welded portion 133 that extends from one long wall surface 113 to the other long wall surface 113.

[0025] (Body 11) The sealed can body 1 has a body 11. The body 11 has a rectangular parallelepiped shape with all six faces being rectangular. However, one of the six faces is an opening 115. The inside of the body 11 is hollow. Battery components such as current collectors are installed inside the body 11 through the opening 115. In this disclosure, "rectangle" means a rectangle in which the dimension of the long side is greater than the dimension of the short side. The body 11 may be a perfect rectangular parallelepiped, or it may have a shape in which the edges of the rectangular parallelepiped are slightly chamfered. The body 11 is a single bent metal plate. Figure 3 shows an example of a metal plate (raw metal plate 3) before bending. First, the metal plate in Figure 2 is bent along the dashed line, and then the ends of the butted or overlapping metal plates are welded to obtain the body 11. When the body 11 is cut along the welded part described later and unfolded, it becomes a single metal plate like the raw metal plate 3 in Figure 3.

[0026] (Lid 12) The sealed container 1 has a lid 12, as shown in Figures 1 and 2, etc. The lid 12 is a rectangular, flat member that seals the opening 115 of the body 11. The body 11 and the lid 12 are joined together to form a single rectangular parallelepiped shape. The lid 12 and the end of the body 11 are joined by welding, crimping, or other arbitrary joining means. The body 11 and the lid 12 are joined together after the battery components are installed inside the body 11. When the sealed container 1 is used as the housing for a horizontal terminal type battery 2, electrodes 21, etc., are provided on the lid 12.

[0027] (Bottom surface 114, long wall surface 113, short wall surface 112, top surface 111) The body 11 has a bottom surface 114, a long wall surface 113, a short wall surface 112, and a top surface 111. These surfaces are defined as follows: ・Bottom surface 114: A surface that connects to one short side of the lid 12, and whose long side (i.e., the long side of the bottom surface 114) is aligned with the vertical direction of the lid 12. ・Long wall surface 113: Two surfaces that connect to the long side of the lid 12, and whose long sides (i.e., the long sides of the long wall surface 113) are aligned with the vertical direction of the lid 12. ・Short wall surface 112: A surface that faces the lid 12. ・Top surface 111: A surface that connects to the other short side of the lid 12, and whose long side (i.e., the long side of the top surface 111) is aligned with the vertical direction of the lid 12.

[0028] For the purposes of this disclosure, the following terms are used: ・Longest direction X: Vertical direction of the lid 12 ・Thickness direction Y: Direction parallel to the short side of the lid 12 ・Height direction Z: Direction parallel to the long side of the lid 12 ・Length a of the sealing can body 1: Dimension of the sealing can body 1 along the longest direction X ・Thickness b of the sealing can body 1: Dimension of the sealing can body 1 along the thickness direction Y ・Height c of the sealing can body 1: Dimension of the sealing can body 1 along the height direction Z When the sealing can body 1 according to this embodiment is used as the housing for an in-vehicle battery 2, it is preferable to install the sealing can body 1 in the vehicle with the height direction Z facing the vertical direction of the vehicle. In this case, the bottom surface 114 or the top surface 111 faces the ceiling of the vehicle.

[0029] However, the installation method described above is merely one example of the use of the sealed container 1. The top surface 111 of the sealed container 1 may be oriented toward the side of an automobile. The terms "top surface 111," "bottom surface 114," and "height direction Z" are used for convenience in describing the sealed container 1. These terms do not limit the use of the sealed container 1 according to this embodiment.

[0030] The dimensions of the long side of the long wall surface 113, the long side of the top surface 111, and the long side of the bottom surface 114 are the same as the length a of the sealed can body 1. The dimensions of the short side of the top surface 111, the short side of the bottom surface 114, the short side of the short wall surface 112, and the short side of the lid 12 are substantially the same as the thickness b of the sealed can body 1. The dimensions of the short side of the long wall surface 113, the long side of the short wall surface 112, and the long side of the lid 12 are substantially the same as the height c of the sealed can body 1. Therefore, a to c satisfy the following equation: a > c > b Preferably, the thickness b of the sealed can body 1 is very small compared to the length a and height c of the sealed can body 1.

[0031] (Bent portion 130 and first welded portion 131) The bottom surface 114, one long wall surface 113, the top surface 111, and the other long wall surface 113 form an annular surface with a rectangular cross-section. Since the body 11 is constructed by bending a single metal plate, the annular surface always includes one or more welded portions. In the sealed can body 1 according to this embodiment, the welded portions that make up the annular surface are formed inside the top surface 111. "Inside the top surface 111" refers to the area excluding the edge of the top surface 111. The boundary between the long wall surface 113 and the top surface 111, and the boundary between the long wall surface 113 and the top surface 111 are all bent portions 130.

[0032] In other words, the bottom surface 114 and the two long walls 113 are connected via the bent portion 130 of the metal plate, the top surface 111 and the two long walls 113 are connected via the bent portion 130 of the metal plate, and inside the top surface 111 there is a welded section that extends from the lid 12 to the short wall 112. Hereinafter, the welded section on the top surface 111 that extends from the lid 12 to the short wall 112 will be referred to as the "first welded section 131".

[0033] Prior to the bending process of the metal sheet, the top surface 111 is divided into a first top surface region 311A ​​and a second top surface region 311B, as shown in Figure 3. The first welded section 131 joins the first top surface region 311A ​​and the second top surface region 311B to form the top surface 111.

[0034] The first weld 131 may extend parallel to the long side of the top surface 111, as illustrated in Figure 2. In the sealed can body 1 of Figure 2, the first weld 131 is considered to be inside the top surface 111. On the other hand, as illustrated in Figure 4, the first weld 131 may be at an angle to the long side of the top surface 111. In Figure 4, both ends of the first weld 131 overlap with the edge of the top surface 111. However, if only the ends of the first weld 131 overlap with the edge of the top surface 111, a thermal distortion suppression effect can be obtained, similar to the first weld 131 in Figure 2. Therefore, the first weld 131 in the sealed can body 1 of Figure 4 is also considered to be inside the top surface 111. On the other hand, if at least a part of the first weld 131 is included in the boundary between the top surface 111 and the long wall surface 113 and extends along that boundary, the first weld 131 is not considered to be inside the top surface 111. For example, if a portion of the first weld 131 is included in the boundary between the top surface 111 and the long wall surface 113, extends along the boundary, and its length is 10% or more of the length a of the sealed can body 1, then the first weld 131 is not considered to be inside the top surface 111. The length a of the sealed can body 1 is equal to the length of the boundary between the top surface 111 and the long wall surface 113. The shape of the first weld 131 is not particularly limited, as long as it extends from the lid 12 to the short wall surface 112 and is separated from the boundary between the top surface 111 and the long wall surface 113. Details of modifications of the first weld 131 will be described later.

[0035] (Second Weld 132) A second weld 132 extends from the top surface 111 to the bottom surface 114 on the short wall surface 112. As shown in Figures 2 and 4, this second weld 132 may be located inside the short wall surface 112 and separated from the boundary between the short wall surface 112 and the long wall surface 113. In this case, the boundary between the short wall surface 112 and each of the pair of long wall surfaces 113 is formed as a bent portion 130 overall. This further suppresses thermal distortion of the sealed can body 1. Note that, as shown in Figure 4, a sealed can body 1 in which the end of the bent portion 130 between the short wall surface 112 and the long wall surface 113 coincides with the end of the second weld 132 is also considered to be a sealed can body 1 in which the second weld 132 is located inside the short wall surface 112 and separated from the boundary between the short wall surface 112 and the long wall surface 113. The second weld 132 in Figure 4, like the second weld 132 in Figure 2, can exert an effect of further suppressing thermal distortion. On the other hand, as shown in Figure 5, the second weld 132 may be provided at the edge of the short wall surface 112, that is, at the boundary between the short wall surface 112 and the long wall surface 113. Even if the weld is provided on the short side of the long wall surface 113, that is, at the boundary between the long wall surface 113 and the short wall surface 112, thermal distortion of the long wall is suppressed. Compared to welding on the long side, welding on the short side has less influence on thermal distortion. However, in this case, the second weld 132 is not considered to be inside the short wall surface 112. For example, if a part of the second weld 132 is included in the boundary between the short wall surface 112 and the long wall surface 113 and extends along the boundary, and its length is 10% or more of the height c of the sealed can body 1, then the second weld 132 is not considered to be inside the short wall surface 112. The height c of the sealed can body 1 is equal to the length of the boundary between the short wall surface 112 and the long wall surface 113. As shown in Figure 6, the second weld 132 may have a Y-shape. In the sealed can body 1 of Figure 6, the end of the second weld 132 coincides with the end of the bent portion 130 located between the short wall surface 112 and the long wall surface 113. However, the portion of the second weld 132 other than the end is not included in the boundary between the short wall surface 112 and the long wall surface 113. Therefore, the second weld 132 in Figure 6 is also considered to be inside the short wall surface 112. The shape of the second weld 132 is not particularly limited as long as it extends from the top surface 111 to the bottom surface 114.

[0036] As shown in Figures 2 and 4, when the second weld 132 is provided inside the short wall surface 112, the short wall surface 112 has a first short wall region 312A and a second short wall region 312B. In the stage prior to bending the metal sheet, the first short wall region 312A and the second short wall region 312B are provided separately, as shown in Figure 3. The second weld 132 joins the first short wall region 312A and the second short wall region 312B to form the short wall surface 112. As shown in Figures 2 and 4, the first short wall region 312A and the second short wall region 312B are connected to the long wall surface 113 via the bent portion 130. Details of modified versions of the second weld 132 will be described later.

[0037] (Third weld 133) The top surface 111 and the short wall surface 112 are connected via a third weld 133 that extends from one long wall surface 113 to the other long wall surface 113. That is, a third weld 133 is provided at the boundary between the top surface 111 and the short wall surface 112.

[0038] (Boundary between short wall surface 112 and bottom surface 114) The boundary between the short wall surface 112 and the bottom surface 114 may be a welded joint or a bent joint 130. For example, in the sealed can body 1 illustrated in Figures 2, 4, and 5, the short wall surface 112 and the bottom surface 114 are connected via a welded joint. Hereinafter, the welded joint provided at the boundary between the short wall surface 112 and the bottom surface 114 will be referred to as the "fourth welded joint 134". On the other hand, in the sealed can body 1 illustrated in Figure 6, the short wall surface 112 and the bottom surface 114 are connected via a bent joint 130.

[0039] Table 1 summarizes the configuration applied to the boundary between two adjacent surfaces in the body 11 of the sealed can body 1 according to this embodiment.

[0040]

[0041] (Effects) The body 11 of the sealed can body 1 according to this embodiment is constructed by bending and welding a single metal plate, rather than by deep drawing. As a result, the thickness of the sealed can body 1 is made uniform throughout, improving the strength of the sealed can body 1. The sealed can body 1 according to this embodiment can be made lighter by reducing its thickness.

[0042] Also, in the body 11 of the sealed can body 1 according to the present embodiment, there are no welding parts inside the long wall surface 113 and along the long sides of the long wall surface 113. The long wall surface 113 has a large area and is prone to thermal distortion. By reducing the amount of welding parts on the long wall surface 113, thermal distortion can be effectively suppressed.

[0043] Further, in the sealed can body 1 according to the present embodiment, the strength against the deflection of the long wall surface 113 is enhanced by the short wall surface 112 and the top surface 111. Therefore, when the material metal plate 3 is bent to form the body 11, it is possible to suppress, as much as possible, the long wall surface area 313 corresponding to the long wall surface 113 from being deformed. Furthermore, the structural strength of the body 11 can be sufficiently ensured.

[0044] Also, when forming the body 11 of the sealed can body 1 by conventional deep drawing, a slight taper occurs over the entire sealed can body 1. When stacking battery cells using the sealed can body 1 as a housing to form a battery 2 unit, the taper of the sealed can body 1 may create a gap between the battery cells, adversely affecting the lifespan of the battery 2. However, since the body 11 of the sealed can body 1 according to the present embodiment is formed by bending, it can be manufactured without generating a taper.

[0045] In addition, since the body 11 of the sealed can body 1 according to the present embodiment is formed by bending a single metal plate, the welding length is suppressed. Therefore, the sealed can body 1 according to the present embodiment has high production efficiency.

[0046] Above, the most basic aspect of the sealed can body 1 according to the present embodiment has been described. Hereinafter, various modifications of the sealed can body 1 according to the present embodiment will be described.

[0047] (Body 11 having a fourth welding part 134) As described above, the boundary between the short wall surface 112 and the bottom surface 114 can be made the fourth welding part 134. For example, in the sealed can body 1 illustrated in FIGS. 2, 4, 5, 7, and 8, the short wall surface 112 and the bottom surface 114 are continuous via the fourth welding part 134.

[0048] When the fourth weld 134 is provided in the fuselage 11, it is more preferable that the second weld 132 and the fourth weld 134 are connected at the end of the fourth weld 134. Figures 4, 5, and 8 show perspective views of an example configuration in which the second weld 132 and the fourth weld 134 are connected at the end of the fourth weld 134. In Figures 4 and 8, the second weld 132 forms the diagonal of the short wall surface 112. In Figure 5, the second weld 132 forms the boundary between the short wall surface 112 and one of the long wall surfaces 113. In either case, the second weld 132 and the fourth weld 134 are connected at the end of the fourth weld 134.

[0049] As illustrated in Figures 4, 5, and 8, when the second weld 132 and the fourth weld 134 are connected at the end of the fourth weld 134, the second weld 132 and the fourth weld 134 can be formed continuously. On the other hand, as illustrated in Figure 2, when the second weld 132 and the fourth weld 134 are connected near the center of the fourth weld 134, it is necessary to form the second weld 132, then temporarily stop the welding work, move the welding equipment, and then resume the welding work. Therefore, the production efficiency of the fuselage 11 in which the second weld 132 and the fourth weld 134 are connected at the end of the fourth weld 134 can be further increased.

[0050] (Body 11 without a fourth weld 134) The boundary between the short wall surface 112 and the bottom surface 114 can also be a bent portion 130. For example, in the sealed can body 1 illustrated in Figure 6, the short wall surface 112 and the bottom surface 114 are connected via a bent portion 130. In this case, the joining of the short wall surface 112 and the bottom surface 114 is carried out inside the short wall surface 112.

[0051] One example of a means for joining the short wall surface 112 and the bottom surface 114 inside the short wall surface 112 is to make the second weld 132 Y-shaped. For example, as illustrated in Figure 6, the second weld 132 may have a second A weld 132A and a second B weld 132B. The second A weld 132A corresponds to the upper half of the letter "Y", and the second B weld 132B corresponds to the lower half of the letter "Y".

[0052] The second A weld 132A extends from one end to the other of the boundary between the short wall surface 112 and the bottom surface 114, is located inside the short wall surface 112, and is bent. In Figure 6, the second A weld 132A has a shape consisting of two straight lines and a vertex between them. However, the second A weld 132A may have another shape, such as a semicircle.

[0053] The second B weld 132B extends from the top surface 111 to the second A weld 132A. Specifically, the second B weld 132B extends from the boundary between the top surface 111 and the short wall surface 112 to the second A weld 132A. In Figure 6, the second B weld 132B is parallel to the long side of the short wall surface 112. However, the second B weld 132B may be inclined with respect to the long side of the short wall surface 112. Also, in Figure 6, the second B weld 132B is connected to the apex of the second A weld 132A. However, the second B weld 132B can be connected to any point on the second A weld 132A. For example, the end of the second B weld 132B may be connected to the end of the second A weld 132A.

[0054] As illustrated in Figure 6, by making the boundary between the short wall surface 112 and the bottom surface 114 a bent portion 130, the welding length can be further reduced. This reduction in welding length leads to further improvements in the production efficiency of the fuselage 11 and further reductions in thermal distortion.

[0055] (Boundary between short wall surface 112 and long wall surface 113) As illustrated in Figure 5, a second welded joint 132 may be provided at the boundary between the short wall surface 112 and one of the long wall surfaces 113. When the short wall surface 112 and one of the long wall surfaces 113 are connected via the second welded joint 132, it becomes easy to provide various battery components such as electrodes 21 on the short wall surface 112. For example, a splitting valve port or a liquid injection port can be installed on the short wall surface 112.

[0056] On the other hand, as illustrated in Figure 2, the short wall surface 112 and the two long wall surfaces 113 may be connected via a bent portion 130 of the metal plate. In this case, the second welded portion 132 is located inside the short wall surface 112. As described above, the long wall surface 113 is the surface most susceptible to thermal distortion. By separating the long wall surface 113 from the second welded portion 132, thermal distortion of the sealed can body 1 can be further reduced.

[0057] (Position of the first weld 131) The first weld 131 is preferably located in the center of the top surface 111, as illustrated in Figures 2, 6, 7, and 14. The center of the top surface 111 is the midpoint between the two long sides of the top surface 111. When the first weld 131 is located in the center of the top surface 111, the first weld 131 and the midpoint between the two long sides of the top surface 111 generally overlap, and the difference between the two is 1 mm or less. As described above, the long wall surface 113 is the surface where thermal distortion is most likely to occur. By positioning the first weld 131 in the center of the top surface 111, the influence of the first weld 131 on the two long wall surfaces 113 can be minimized, and the thermal distortion of the sealed can body 1 can be further reduced.

[0058] On the other hand, the first weld 131 may be provided at a location away from the center of the top surface 111. For example, as illustrated in Figures 4, 5, and 8, the end of the first weld 131 and the end of the third weld 133 may be connected. In this case, part or all of the first weld 131 is inclined with respect to the long side of the top surface 111. When the end of the first weld 131 and the end of the third weld 133 are connected, the first weld 131 and the third weld 133 can be manufactured by continuous welding. This further improves the production efficiency of the fuselage 11.

[0059] (Positional relationship between the first weld 131 and the second weld 132) The end of the first weld 131 and the end of the second weld 132 may be connected. Figures 2, 5, and 6 show an example of a fuselage 11 in which the end of the first weld 131 and the end of the second weld 132 are connected. When the end of the first weld 131 and the end of the second weld 132 are connected, the first weld 131 and the second weld 132 can be manufactured by continuous welding. This further improves the production efficiency of the fuselage 11.

[0060] On the other hand, the first weld 131 and the second weld 132 may be separated. Specifically, at the boundary between the top surface 111 and the short wall surface 112, the end of the first weld 131 and the end of the second weld 132 may be separated. Figures 4, 7, and 8 show examples of a body 11 in which the first weld 131 and the second weld 132 are separated.

[0061] As shown in Figures 2, 5, and 6, when the end of the first weld 131 and the end of the second weld 132 are connected, the first weld 131, the second weld 132, and the third weld 133 intersect at a single point on the boundary between the top surface 111 and the short wall surface 112. Welding defects are slightly more likely to occur at the intersection of these welds. If it is necessary to further improve the joining quality of the sealed can body 1, it is preferable to separate the first weld 131 and the second weld 132.

[0062] (Connection of the first weld 131, the second weld 132, and the third weld 133) As illustrated in Figures 4 and 8, the end of the first weld 131 may be connected to one end of the third weld 133, and the end of the second weld 132 may be connected to the other end of the third weld 133. In this case, the first weld 131, the second weld 132, and the third weld 133 form a single weld without branching. More preferably, the end of the first weld 131 may be connected to one end of the third weld 133, one end of the second weld 132 may be connected to the other end of the third weld 133, and the other end of the second weld 132 may be connected to the end of the fourth weld 134. In this case, the first weld 131, the second weld 132, the third weld 133, and the fourth weld 134 form a single weld without any branching.

[0063] If the first weld 131, the second weld 132, and the third weld 133 are a single weld, the first weld 131, the second weld 132, and the third weld 133 can be manufactured by continuous welding. If the first weld 131, the second weld 132, the third weld 133, and the fourth weld 134 are a single weld, the first weld 131, the second weld 132, the third weld 133, and the fourth weld 134 can be manufactured by continuous welding. In these cases, the production efficiency of the fuselage 11 can be further increased. In these cases, it is also possible to avoid the first weld 131, the second weld 132, and the third weld 133 intersecting at a single point.

[0064] (Applications of the sealed can body 1) The sealed can body 1 according to this embodiment is preferably used as the housing of the battery 2, i.e., as a battery case. The sealed can body 1 according to this embodiment has the structural strength required for the housing of the battery 2, is lightweight, has low thermal distortion, and has high production efficiency. Therefore, by using the sealed can body 1 as a battery case, the performance of the battery case can be dramatically improved.

[0065] (2. Battery 2) Battery 2 according to another embodiment of the present disclosure comprises a battery case. The battery case is the sealed container 1 according to the present embodiment described above.

[0066] A more specific example of the battery 2 is described below. The battery 2 has an electrode body housed inside a battery case, positive and negative current collectors electrically connected to the electrode body, and an electrolyte. The battery case lid 12 is provided with electrodes 21 electrically connected to the current collectors. The lid 12 is provided with an electrolyte injection port and an injection plug to seal the injection port. The lid 12 is also provided with a cleavage valve port and a cleavage valve to seal the cleavage valve port. The cleavage valve port cleaves open when the pressure inside the battery case increases due to some abnormality, releasing the pressure inside the battery case.

[0067] The battery 2 according to this embodiment has high structural strength, is lightweight, exhibits low thermal distortion, and has high production efficiency.

[0068] The battery 2 according to this embodiment may be a battery cell. A battery cell is the smallest unit of a battery in a battery module. A battery module is constructed by electrically connecting multiple battery cells. Multiple battery modules can be further electrically connected to form a battery pack. A battery pack can also be constructed by electrically connecting a large number of battery cells without constructing a battery module. A battery module or battery pack can be used, for example, as a power source for an electric vehicle. However, it is not essential to use a battery module or battery pack in an electric vehicle. It is also possible to mount a large number of battery cells in an electric vehicle without constructing a module or pack.

[0069] (3. Method for Manufacturing the Sealed Can Body 1) Another embodiment of the present disclosure is a method for manufacturing the sealed can body 1, which includes a lid 12 and a body 11, comprising the steps of: manufacturing a material metal plate 3; bending a single material metal plate 3 to form a rectangular parallelepiped shape; and welding the portions of the material metal plates 3 that are butted together or overlapped in the bending step, wherein the material metal plate 3 has a rectangular bottom region 314 and two identical elongated wall regions 313, each having a rectangular shape and positioned on both long sides of the bottom region 314, with the dimensions of the long sides of the elongated wall regions 313 being equal to the dimensions of the bottom region 314 A long wall region 313, the long side of which is the same as the long side of the long wall region 314, and the short side of which is larger than the short side of the base region 314, and the long side of the base region 314 and the long side of the long wall region 113 are in contact with each other with their ends aligned, and a first top region 311A, which is located on the long side of one of the long wall regions 313 opposite to the base region 314, and the long side of the first top region 311A ​​is the same as the long side of the base region 314, and the long side of the base region 314 and the long side of the long wall region 313 are in contact with each other with their ends aligned, and a second top region 311B is located on the long side of the other long wall region 313 opposite to the bottom region 314, the dimension of the long side of the second top region 311B is the same as the dimension of the long side of the bottom region 314, and the long side of the bottom region 314 and the long side of the long wall region 313 are in contact with each other with both ends aligned. and first short wall region 312A is located on one short side of one long wall region 313, the dimension of the long side of the first short wall region 312A is the same as the dimension of the short side of the long wall region 313, and the short side of one long wall region 313 and the long side of the first short wall region 312A are However, it has a first short wall region 312A and a second short wall region 312B, which are in contact with each other with their ends aligned. The second short wall region 312B is located on the short side of the other long wall region 313 where the first short wall region 312A is located, and the dimension of the long side of the second short wall region 312B is the same as the dimension of the short side of the long wall region 313, and the short side of the other long wall region 313 and the long side of the second short wall region 312B are in contact with each other with their ends aligned. The first top region 311A ​​and the second top region 311B have a shape obtained by dividing the bottom region 314 into two parts.The first short wall region 312A and the second short wall region 312B have a rectangular shape which is divided into two parts, with the length of the long side being the same as the length of the short side of the long wall region 313 and the length of the short side being the same as the length of the short side of the bottom region 314. In the bending process, the end on the long side of the first top region 311A ​​and the end on the long side of the second top region 311B are butted together or overlapped. In the welding process, the end on the long side of the first top region 311A ​​and the end on the long side of the second top region 311B are welded together to form the first welded part 131 and the top surface 111. In the bending process, the end on the long side of the first short wall region 312A and the end on the long side of the second short wall region 312B are butted together or overlapped. In the welding process, the long-side end of the first short wall region 312A and the long-side end of the second short wall region 312B are welded together to form the second welded portion 132 and the short wall surface 112. In the bending process, the short-side ends of the rectangular regions formed by the first top surface region 311A ​​and the second top surface region 311B are butted together or overlapped, and in the welding process, the short-side ends of the rectangular regions formed by the first top surface region 311A ​​and the second top surface region 311B are welded together to form the third welded portion 133.

[0070] (S1 Manufacturing of the raw material metal plate 3) In the manufacturing method of the sealed can body 1 according to this embodiment, first, a raw material metal plate 3 as illustrated in Figure 3 is manufactured. The raw material metal plate 3 has a rectangular parallelepiped shape in which all six sides are rectangular, and has the shape of an unfolded body 11 which has an opening 115 on one side. An example of the specific shape of the raw material metal plate 3 is described below.

[0071] The material metal plate 3 has a bottom region 314, two long wall regions 313, a first top region 311A, a second top region 311B, a first short wall region 312A, and a second short wall region 312B. The bottom region 314, the two long wall regions 313, the first top region 311A, and the second top region 311B are arranged in a row to form a strip-shaped region. The first short wall region 312A and the second short wall region 312B are located on one side of this strip-shaped region. The material metal plate 3 has the shape obtained by cutting the above-described body at the welded joint and unfolding it.

[0072] (Bottom region 314) When the material metal plate 3 is bent to form the body 11, the bottom region 314 becomes the bottom surface 114 of the body 11. The bottom region 314 has a rectangular shape. The dimension of the long side of the bottom region 314 is the same as the length a of the sealed can body 1. The dimension of the short side of the bottom region 314 is the same as the thickness b of the sealed can body 1.

[0073] (Long wall region 313) When the material metal plate 3 is bent to form the body 11, the two long wall regions 313 each become the two long wall surfaces 113 of the body 11. The long wall regions 313 have a rectangular shape. The two long wall regions 313 are each positioned on both long sides of the bottom region 314. That is, the bottom region 314 is positioned between the two long wall regions 313.

[0074] The length of the long side of the long wall region 313 is the same as the length a of the sealed can body 1. The length of the short side of the long wall region 313 is the same as the height c of the sealed can body 1. Also, the length c of the short side of the long wall region 313 is greater than the length b of the short side of the bottom region 314. The long sides of the long wall region 313 and the long side of the bottom region 314 are in contact with each other with their ends aligned.

[0075] (First top surface region 311A ​​and second top surface region 311B) The first top surface region 311A ​​and the second top surface region 311B become the top surface 111 of the body 11 when the material metal plate 3 is bent to form the body 11. The first top surface region 311A ​​and the second top surface region 311B have a shape in which the top surface 111 is divided into two. In the material metal plate 3 of Figure 3, the first top surface region 311A ​​and the second top surface region 311B are rectangular in shape. On the other hand, in the material metal plate 3 used as the material for the body 11 of Figure 4, the shape of the first top surface region 311A ​​and the second top surface region 311B is a right triangle.

[0076] The dimensions of the long sides of the first top surface region 311A ​​and the second top surface region 311B are the same as the length a of the sealed can body 1. The dimensions of the rectangle formed by combining the first top surface region 311A ​​and the second top surface region 311B are the same as the dimensions of the top surface region. When overlapping and welding the first top surface region 311A ​​and the second top surface region 311B, an overlap allowance 32 may be provided on the long sides of the first top surface region 311A ​​and / or the second top surface region 311B. When butt welding the first top surface region 311A ​​and the second top surface region 311B, an overlap allowance 32 is not necessary.

[0077] The first top surface area 311A ​​is located on the long side of one long wall surface area 313, opposite to the bottom surface area 314. The long side of the long wall surface area 313 and the long side of the first top surface area 311A ​​are in contact with each other with their ends aligned. The second top surface area 311B is located on the long side of the other long wall surface area 313, opposite to the bottom surface area 314. The long side of the long wall surface area 313 and the long side of the second top surface area 311B are in contact with each other with their ends aligned. The long wall surface area 313 and the bottom surface area 314 are located between the first top surface area 311A ​​and the second top surface area 311B.

[0078] The first top surface region 311A, one long wall region 313, the bottom surface region 314, the other long wall region 313, and the second top surface region 311B are arranged in a line. Furthermore, all the short sides of these regions are aligned on the same line. By folding the strip-shaped region formed by these regions at a right angle at the boundary of these regions, a cylinder with a rectangular cross-section is formed. One opening of the cylinder is sealed by the first short wall region 312A and the second short wall region 312B, which will be described later, and the other opening is sealed by a lid.

[0079] (First short wall region 312A and second short wall region 312B) The first short wall region 312A and the second short wall region 312B become the short walls 112 of the body 11 when the material metal plate 3 is bent to form the body 11. The first short wall region 312A and the second short wall region 312B have a shape obtained by dividing a rectangle into two, where the dimension of the long side is the same as the dimension of the short side of the long wall region, and the dimension of the short side is the same as the dimension of the short side of the bottom region. This shape is the same as the shape of the lid and the short walls 112. In the material metal plate 3 of Figure 3, the first short wall region 312A and the second short wall region 312B are rectangular in shape. On the other hand, in the material metal plate 3 used as the material for the body 11 of Figure 4, the shape of the first short wall region 312A and the second short wall region 312B is a right triangle.

[0080] Note that the short wall surface 112 does not necessarily have to be divided. In the material metal plate 3 used as the material for the fuselage 11 in Figure 5, the short wall surface region 312 is not divided. In this case, the material metal plate 3 has one short wall surface region 312. The undivided short wall surface region 312 has a rectangular shape.

[0081] The dimension of the long side of the short wall region 312, or the region formed by combining the first short wall region 312A and the second short wall region 312B, is the same as the height c of the sealed can body 1. The dimension of the short side of the short wall region 312, or the dimension of the short side of the region formed by combining the first short wall region 312A and the second short wall region 312B, is the same as the thickness b of the sealed can body 1. Overlaps 32 can also be provided at the ends of the first short wall region 312A and the second short wall region 312B as needed.

[0082] The short wall region 312 is located on the short side of one of the long wall regions 313. If the short wall region 312 is divided, the first short wall region 312A is located on the short side of one of the long wall regions 313, and the second short wall region 312B is located on the short side of the other long wall region 313. The short side of the long wall region 313 and the long side of the first short wall region 312A are in contact with each other with their ends coincided. Also, the long side of the long wall region 313 and the short side of the second short wall region 312B are connected with their ends coincided. The long side of the long wall region 313 and the short side of the first short wall region 312A are on the same line, and the long side of the long wall region 313 and the short side of the second short wall region 312B are on the same line.

[0083] A metal sheet 3 having such a shape can be manufactured, for example, by punching out a bulk metal sheet or by laser cutting a bulk metal sheet. The manufacturing method of the metal sheet 3 can be appropriately selected depending on its shape and material.

[0084] (S2 Bending of the metal sheet 3) (S3 Welding of the metal sheet 3) Next, the metal sheet 3 is bent into a rectangular parallelepiped shape. Then, the parts of the metal sheet 3 that are butted together or overlapping are welded together. This forms the body 11. Details of bending and welding are described below.

[0085] The points to be bent are the boundaries of the bottom region 314, the two long wall regions 313, the first top region 311A, the second top region 311B, and the short wall region 312, as described above. These boundaries are bent at right angles to form the bent portion 130.

[0086] (Formation of the first welded portion 131) As described above, the first top surface region 311A, one long wall region 313, the bottom surface region 314, the other long wall region 313, and the second top surface region 311B are arranged in a row. When the boundaries of these regions are bent at a right angle, the long side end of the first top surface region 311A ​​and the long side end of the second top surface region 311B are butted together or overlapped. When the long side end of the first top surface region 311A ​​and the long side end of the second top surface region 311B are butt-welded or overlap-welded, the first welded portion 131 and the top surface are formed. These regions then constitute a cylinder with a rectangular cross-section.

[0087] (Formation of the second welded portion 132) With the cylinder formed as described above, if the boundary between the long wall region 313 and the first short wall region 312A, and the boundary between the long wall region 313 and the second short wall region 312B are further bent at a right angle, the long side end of the first short wall region 312A and the long side end of the second short wall region 312B will be butt-welded or overlapped. When the long side end of the first short wall region 312A and the long side end of the second short wall region 312B are butt-welded or overlap-welded, the second welded portion 132 and the short wall are formed.

[0088] (Formation of the third welded portion 133) When the boundary between the long wall region 313 and the short wall region 312 is bent at a right angle by bending, the short-side end of the first top surface region 311A ​​and the short-side end of the short wall region 312 come into a butt joint or overlapping state. Furthermore, the short-side end of the second top surface region 311B and the short-side end of the short wall region 312 come into a butt joint or overlapping state. In other words, the short-side ends of the rectangular region formed by the first top surface region and the second top surface region come into a butt joint or overlapping state. When these are butt-welded or overlap-welded, the third welded portion 133 is formed.

[0089] (Formation of the fourth weld 134) Furthermore, as a result of the bending process described above, the first short wall region 312A and the short side end of the rectangular region formed by the first short wall region 312A and the short side end of the bottom region 314 are butted together or overlapped. When these are butt welded or overlapped welded, the fourth weld 134 is formed.

[0090] (S4 Joining the body 11 and the lid 12) The body 11 is manufactured by bending and welding a metal plate 3. The body 11 has a rectangular parallelepiped shape with all six sides being rectangular, and one side is an opening 115. The sealed can body 1 is manufactured by attaching the lid 12 to this opening 115 and joining the body 11 and the lid 12. The method of joining the body 11 and the lid 12 is not particularly limited. Examples of joining methods include crimping and welding.

[0091] Furthermore, when using the sealed can body 1 as a battery case, it is necessary to install the battery components inside the body 11 before joining the body 11 and the lid 12.

[0092] (Formation of the second welded section 132 and the fourth welded section 134 by continuous welding) Figure 9 shows a plan view of the material metal plate 3, which is the material of the fuselage 11 in Figure 4. As shown in Figure 9, the shapes of the first short wall region 312A and the second short wall region 312B may be right-angled triangles. Here, the sides that form the right angle of the right-angled triangle are called the short side and the long side, and the side opposite the right angle is called the hypotenuse. The hypotenuse may be a straight line or a curve. The dimensions of the short sides of the first short wall region 312A and the second short wall region 312B are the same as the dimensions of the short side of the base region 314. Also, the hypotenuse of the first short wall region 312A and the hypotenuse of the second short wall region 312B are parallel before bending. An overlap 32 may be provided on the hypotenuse of the first short wall region 312A and / or the hypotenuse of the second short wall region 312B.

[0093] When the material metal plate 3 having the above configuration is bent, the hypotenuse of the first short wall region 312A and the hypotenuse of the second short wall region 312B come into butt or overlapping position. When the hypotenuse of the first short wall region 312A and the hypotenuse of the second short wall region 312B are welded together, a second welded portion 132 is formed along the diagonal of the short wall surface 112.

[0094] In this case, the second weld 132 and the fourth weld 134 can be formed by continuous welding. That is, when manufacturing the second weld 132 and the fourth weld 134, there is no need to stop welding and move the welding position. This further improves the production efficiency of the fuselage 11.

[0095] (Omission of the fourth weld 134 using the third short wall region 312C) Figure 10 shows a plan view of the material metal plate 3, which is the material of the body 11 in Figure 6. The material metal plate 3 in Figure 10 has a third short wall region 312C provided on the short side of the bottom region 314. The end of the third short wall region 312C extends from one end to the other on the short side of the bottom region 314 and is bent. The end of the third short wall region 312C is the boundary between the third short wall region 312C and the bottom region 314. In the bending process S2, the boundary between the third short wall region 312C and the bottom region 314 is made into a bent portion 130.

[0096] Furthermore, the first short wall region 312A and the second short wall region 312B of the material metal plate 3 in Figure 10 are provided with notches having a shape that matches the third short wall region 312C. When the material metal plate 3 is bent, the end of the third short wall region 312C and the end of the notch come into contact or overlap. The first short wall region 312A, the second short wall region 312B, and the third short wall region 312C constitute the short wall surface 112 of the fuselage 11.

[0097] After bending the material metal plate 3, the end of the third short wall region 312C and the end of the notch are butt-welded or overlap-welded. This forms the second A weld 132A shown in Figure 6. Also, the long-side end of the first short wall region 312A and the long-side end of the second short wall region 312B are welded together. This forms the second B weld 132B shown in Figure 6. According to the material metal plate 3 of Figure 10, a Y-shaped second weld 132 can be formed, and the formation of the fourth weld 134 can be omitted.

[0098] (Position of the first weld 131) As explained with reference to Figure 2, from the viewpoint of further suppressing thermal distortion, it is preferable to position the first weld 131 in the center of the top surface 111. That is, in welding process S3, it is preferable to weld the end on the long side of the first top surface region 311A ​​and the end on the long side of the second top surface region 311B in the center of the long sides of the two long wall regions 313 to form the first weld 131. In order to manufacture such a body 11, it is preferable to make both the first short wall region 312A and the second short wall region 312B of the material metal plate 3 into rectangular shapes of the same dimensions. This makes it possible to position the first weld 131 in the center of the long sides of the two long wall regions 313 in the welding process.

[0099] (Separation between the first weld 131 and the second weld 132) As explained with reference to Figures 4 and 7, from the viewpoint of further improving the joining quality of the sealed can body 1, it is preferable that the first weld 131 and the second weld 132 are separated. In order to manufacture such a body 11, it is preferable that the dimension of the short side of the first top surface region 311A ​​on the side of the first short wall surface region 312A is different from the dimension of the short side of the first short wall surface region 312A on the side of the first top surface region 311A ​​in the raw metal plate 3. In this case, the first top surface region 311A ​​and the first short wall surface region 312A are in contact with the same long wall surface region 313.

[0100] Figure 9 shows a plan view of the material metal plate 3 that will be used to form the body 11 in Figure 4. In Figure 9, both the first top surface region 311A ​​and the first short wall surface region 312A are in contact with the long wall surface region 313 on the right side of the paper. The dimension of the short side of the first top surface region 311A ​​on the side of the first short wall surface region 312A is 0. The dimension of the short side of the first short wall surface region 312A on the side of the first top surface region 311A ​​is b. When the material metal plate 3 having such a configuration is bent to form the body 11, the butt joint or overlapping joint of the first top surface region 311A ​​and the second top surface region 311B is formed discontinuously with the butt joint or overlapping joint of the first short wall surface region 312A and the second top surface region 311B. By welding such a body 11, the first welded joint 131 and the second welded joint 132 can be separated, as illustrated in Figure 4.

[0101] Figure 11 shows a plan view of the material metal plate 3 that will be used to form the body 11 in Figure 7. In Figure 11, both the first top surface region 311A ​​and the first short wall surface region 312A are in contact with the long wall surface region 313 on the right side of the paper. The dimension of the short side of the first top surface region 311A ​​on the side of the first short wall surface region 312A is approximately b / 2. The dimension of the short side of the first short wall surface region 312A on the side of the first top surface region 311A ​​is greater than b / 2 and less than b. When the material metal plate 3 having such a configuration is bent to form the body 11, the abutting or overlapping portion of the first top surface region 311A ​​and the second top surface region 311B is formed discontinuously with the abutting or overlapping portion of the first short wall surface region 312A and the second top surface region 311B. By welding the fuselage 11 in this manner, the first welded portion 131 and the second welded portion 132 can be separated, as illustrated in Figure 7.

[0102] (Connection of the first weld 131, the second weld 132, and the third weld 133) On the other hand, as explained with reference to Figures 4 and 8, from the viewpoint of further improving the productivity of the sealed can body 1, it is preferable that the first weld 131, the second weld 132, and the third weld 133 are connected at their ends to form a single weld. In order to manufacture such a weld, the dimensions of the short sides of the second top surface region 311B on the side of the first short wall region 312A and the second short wall region 312B are made the same as the dimensions b of the short side of the bottom surface region 314. Furthermore, the dimensions of the short sides of the first short wall region 312A or the second short wall region 312B that are joined to the short sides of the second top surface region 311B on the side of the first short wall region 312A and the second short wall region 312B are made the same as the dimensions b of the short side of the bottom surface region 314.

[0103] Figure 9 shows a plan view of the material metal plate 3 that will be used as the material for the body 11 in Figure 4. In Figure 9, the dimension of the short side α1 on the side of the first short wall region 312A and the second short wall region 312B of the second top surface region 311B is the same as the dimension b of the short side of the bottom surface region 314. Also in Figure 9, the short side β1 on the side of the first top surface region 311A ​​of the first short wall region 312A is joined to α1. The dimension of β1 is also the same as the dimension b of the short side of the bottom surface region 314. By bending the material metal plate 3 having such a configuration to form the body 11, and then butting the ends of the material metal plate 3 together or overlapping them, the first weld 131, the third weld 133, and the second weld 132 can be made into a single weld.

[0104] Figure 12 shows a plan view of the material metal plate 3 that will be used as the material for the body 11 in Figure 8. In Figure 12, the dimension of the short side α2 on the side of the first short wall region 312A and the second short wall region 312B of the second top surface region 311B is the same as the dimension b of the short side of the bottom surface region 314. Also in Figure 12, the short side β2 on the side of the first top surface region 311A ​​of the first short wall region 312A is joined to α2. The dimension of β2 is also the same as the dimension b of the short side of the bottom surface region 314. By bending the material metal plate 3 having such a configuration to form the body 11, and butting the ends of the material metal plate 3 together or overlapping them, the first weld 131, the third weld 133, and the second weld 132 can be made into a single weld.

[0105] Note that the first top surface area 311A ​​and the second top surface area 311B are simply distinctions made for convenience from the two divided top surfaces 111, and there is no need to distinguish between them. Therefore, "first top surface area 311A" in the above-described explanation of the material metal plate 3 may be replaced with "second top surface area 311B". That is, or, the dimensions of the short sides of the first top surface area 311A ​​on the side of the first short wall surface area 312A and the second short wall surface area 312B may be the same as the dimensions b of the short side of the bottom surface 114, and the dimensions of the short sides of the first short wall surface area 312A or the second short wall surface area 312B that are joined to the short sides of the first short wall surface area 312A and the second short wall surface area 312B on the side of the first top surface area 311A ​​may be the same as the dimensions b of the short side of the bottom surface 114.

[0106] (Exclusion of welding start or end using relief sections) The material metal plate 3 may have relief sections 331 and 332, as illustrated in Figure 13. The relief sections 331 and 332 are regions where the welding start and / or end points are located. The relief sections 331 and 332 are cut out from the sealing can body 1. By cutting out the relief sections 331 and 332 from the sealing can body 1, the welding start or end can be excluded from the sealing can body 1.

[0107] The start of a weld is the region of the weld bead formed from the start of welding until the weld stabilizes. The end of a weld is the region of the weld bead formed immediately before the end of welding. The region of the weld bead formed when the weld is stable is sometimes called the steady-state region. In the steady-state region, the width of the weld bead is approximately constant, that is, the difference between the maximum and minimum widths of the weld bead is 0.7 mm or less. On the other hand, the start and end of the weld bead have different widths or surface characteristics than the steady-state region. The start or end of the weld bead can be distinguished from the steady-state region by visual inspection of the weld bead.

[0108] Welding defects are prone to occur at the beginning and end of welds. In particular, hole-like defects called craters are prone to occur at the end of welds. By excluding one or both of the beginning and end of the weld from the sealing can body 1, the reliability of the sealing can body 1 can be further improved. It is especially preferable to exclude the end of the weld from the sealing can body 1. When the beginning and end of the weld are excluded from the sealing can body 1, the weld of the sealing can body 1 consists substantially only of the steady-state portion.

[0109] The specific configuration of the relief section will be explained with reference to Figures 13 and 14. An example of a relief section is the first relief section 331 provided in the first top surface area 311A ​​and the second top surface area 311B. The first relief section 331 has a shape that extends the first top surface area 311A ​​and the second top surface area 311B along the long side direction of the first top surface area 311A ​​and the second top surface area 311B.

[0110] When the end of the welded portion of the sealed can body 1 is excluded, the welding to form the first welded portion 131 is started from the opposite side of the first relief portion 331. This forms a body 11 having the first relief portion 331 at the end of the top surface 111, as illustrated in Figure 14. The end of the first welded portion 131 is formed within the first relief portion 331. Since the first relief portion 331 is unnecessary in the sealed can body 1, it is cut off. This results in a first welded portion 131 from which the end has been excluded.

[0111] Another example of a relief section is a second relief section 332 provided in the first short wall region 312A and the second short wall region 312B. The second relief section 332 has a shape that extends the first short wall region 312A and the second short wall region 312B along the long side direction of the first short wall region 312A and the second short wall region 312B.

[0112] When the end of the weld of the sealed can body 1 is excluded, welding to form the second weld 132 is started from the opposite side of the second relief portion 332. This forms a body 11 having the second relief portion 332 at the end of the short wall surface 112, as illustrated in Figure 14. The end of the second weld 132 is formed within the second relief portion 332. Since the second relief portion 332 is unnecessary in the sealed can body 1, it is cut off. This results in a second weld 132 with its end excluded. Subsequently, a third weld 133 is formed.

[0113] The above describes the case where the end of the weld is inside the relief section. As described above, when welding, the starting point of the welding to form the first weld 131 and / or the second weld 132 is set inside the relief section, and the manufacturing method of the sealed can body 1 further includes a step of cutting off the relief section after welding, thereby obtaining the first weld 131 and / or the second weld 132 from which one or both of the starting and ending ends are excluded. It is preferable that at least one of the first relief section 331 and the second relief section 332 is provided in the material metal plate 3, and it is even more preferable that both are provided in the material metal plate 3. The above description used the end as an example, but the same applies to the starting end. In addition, relief sections may be formed on both the starting and ending sides. For example, if the starting end of the weld is excluded from the sealed can body 1, the welding to form the first weld 131 can be started from the relief section.

[0114] (Uses of the sealed can body 1) The sealed can body 1 obtained by the manufacturing method according to this embodiment is preferably used as the housing of the battery 2, i.e., as a battery case. The manufacturing method of the sealed can body 1 according to this embodiment can produce a sealed can body 1 that has the structural strength required for the housing of the battery 2, is lightweight, has low thermal distortion, and has high production efficiency.

[0115] (4. Method for Manufacturing Battery 2) Another embodiment of the present disclosure provides a method for manufacturing battery 2, comprising the step of manufacturing a sealed can body 1. The step of manufacturing the sealed can body 1 is the method for manufacturing the sealed can body 1 according to the present embodiment described above.

[0116] While embodiments of the present disclosure have been described above, the disclosure is not limited thereto and can be modified as appropriate without departing from the technical idea. Below, more preferred examples of the sealed container, battery, method for manufacturing the sealed container, and method for manufacturing the battery according to the present embodiment will be described. Unless otherwise specified, the configurations described below are applicable to all of the sealed container, battery, method for manufacturing the sealed container, and method for manufacturing the battery.

[0117] (Material of the body 11 and lid 12) The body 11 of the sealed can body 1 is a metal plate. Preferred configurations for the metal plate are described below. The configurations described below are also applicable to raw metal plates.

[0118] Examples of metal plates constituting the body 11 include Ni-plated steel sheets, stainless steel sheets, and aluminum alloy sheets. The thickness of the Ni-plated layer on the Ni-plated steel sheet is preferably, for example, 0.7 to 7.0 μm. The Ni-plated layer is a plating layer mainly composed of Ni, optionally containing elements such as Co, W, and Fe. Examples of stainless steel sheets include SUS304, SUS316, SUS430, SUS436S, SUS439, and Sn-added SUS (product names NSSC FW1, NSSC FW2). From the viewpoint of reducing manufacturing costs, it is preferable to use ferritic stainless steel sheets such as SUS439. Examples of aluminum alloy sheets include 1000 series and 3000 series alloys. From the viewpoint of preventing galvanic corrosion, it is preferable that the material of the lid 12 be the same as the material of the body 11.

[0119] The thickness of the metal plate constituting the sealing can body 1 is preferably in the range of 0.15 mm to 2.5 mm. In order to reduce the thickness of the metal plate while ensuring the strength of the sealing can body 1, it is preferable to use a high-strength material for the metal plate. For example, Ni-plated steel sheet or stainless steel sheet is preferable because it has high strength. When the metal plate is a Ni-plated steel sheet or stainless steel sheet, it is even more preferable to set the thickness of the metal plate in the range of 0.15 to 1.6 mm. The plate thickness of the body 11 and the lid 12 may be different, and the plate thickness of the lid 12, on which the electrodes are placed, may be increased to increase its rigidity.

[0120] (Welded parts and welding methods) The welded parts may be butt welds or lap welds. A butt weld is a weld formed by butt welding the end faces of the material metal plates 3 together. A lap weld is a weld obtained by overlapping the ends of the material metal plates 3 and performing through welding or fillet welding. When forming a lap weld, an overlap allowance 32 is provided in the material metal plates 3.

[0121] The weld bead formed in the welded area is preferably a laser weld bead or an arc weld bead. The method for welding the material metal plate 3 is preferably laser welding or arc welding. Suitable examples of laser welding include fiber lasers, disk lasers, and semiconductor lasers. Laser welding may be performed using a continuous-wave laser or a pulse-wave laser. If necessary, a filler material such as filler wire may be added to the welded area.

[0122] (Variation in the thickness of the long wall surface 113) The long wall surface 113 is the widest surface in the sealed can body 1 and is prone to thermal distortion. From the viewpoint of suppressing thermal distortion, it is preferable that the variation in the thickness of the long wall surface 113 be small. For example, it is preferable that the variation in the thickness of the long wall surface 113 is 0.8% or less of the maximum thickness of the long wall surface 113.

[0123] 1. Sealed container 11. Body 111. Top surface 112. Short wall surface 113. Long wall surface 114. Bottom surface 115. Opening 12. Lid 130. Folded section 131. First welded section 132. Second welded section 132A. Second A welded section 132B. Second B welded section 133. Third welded section 134. Fourth welded section 14. Sealed joint 2. Battery 21. Electrode 3. Material metal plate 311A. First top surface area 311B. Second top surface area 312. Short wall surface area 312A. First short wall surface area 312B. Second short wall surface area 312C. Third short wall surface area 313. Long wall surface area 314. Bottom surface area 32. Overlap 331. First relief section 332. Second relief section X Length direction (Y), Thickness direction (Z), Height direction

Claims

1. A sealed container comprising: a body having a rectangular parallelepiped shape with all six faces being rectangular and one face being an opening; and a lid that seals the opening, wherein the body is a single bent metal plate, and the body has: a bottom surface connected to one of the short sides of the lid and whose long side is aligned with the vertical direction of the lid; two long wall surfaces connected to the long side of the lid and whose long sides are aligned with the vertical direction of the lid; a short wall surface facing the lid; and a top surface connected to the other short side of the lid and whose long side is aligned with the vertical direction of the lid, wherein the bottom surface and the two long wall surfaces are connected via the bent portion of the metal plate, and the top surface and the two long wall surfaces are connected via the bent portion of the metal plate, and a first welded portion extending from the lid to the short wall surface exists inside the top surface. The short wall surface has a second weld extending from the top surface to the bottom surface, and the top surface and the short wall surface are connected by a third weld extending from one long wall surface to the other long wall surface, forming a sealed can body.

2. The sealing can body according to claim 1, wherein the bottom surface and the short wall surface are connected via a fourth weld.

3. The sealing can body according to claim 2, wherein the second weld and the fourth weld are connected at the end of the fourth weld.

4. The sealed can body according to claim 1, wherein the second welded portion comprises a second A welded portion extending from one end to the other of the boundary between the short wall surface and the bottom surface, located inside the short wall surface, and being bent, and a second B welded portion extending from the boundary between the top surface and the short wall surface to the second A welded portion, and the bottom surface and the short wall surface are connected via the bent portion of the metal plate.

5. The sealing can body according to any one of claims 1 to 4, wherein the short wall surface and the two long wall surfaces are connected via the bent portion of the metal plate.

6. The sealing can body according to any one of claims 1 to 4, wherein the first welded portion is located in the center of the top surface.

7. The sealing can body according to any one of claims 1 to 4, wherein the first weld and the second weld are separated.

8. The sealing can body according to claim 7, wherein the end of the first weld and one end of the third weld are connected, and the end of the second weld and the other end of the third weld are connected.

9. A battery case, the sealed container according to any one of claims 1 to 4.

10. The sealing can body according to any one of claims 1 to 4, wherein the second welded portion is provided inside the short wall surface.

11. The sealing can body according to any one of claims 1 to 4, wherein the metal plate is a Ni-plated steel plate, a stainless steel plate, or an aluminum alloy plate.

12. A battery comprising a battery case, wherein the battery case is a sealed can body according to any one of claims 1 to 4.

13. A method for manufacturing a sealed can body including a lid and a body, comprising: a step of manufacturing a material metal plate; a step of bending one of the material metal plates to form a rectangular parallelepiped shape; and a step of welding the portions of the material metal plates that are butted together or overlapped in the bending step, wherein the material metal plate comprises: a bottom region having a rectangular shape; and two identical long wall regions, each having a rectangular shape and positioned on both long sides of the bottom region, wherein the dimensions of the long sides of the long wall regions are the same as the dimensions of the long sides of the bottom region, and the dimensions of the short sides are greater than the dimensions of the short sides of the bottom region, and the long sides of the bottom region and the long sides of the long wall regions are in contact with each other with their ends aligned, A first top surface region, located on the long side of one of the long wall regions opposite to the bottom surface region, wherein the dimension of the long side of the first top surface region is the same as the dimension of the long side of the bottom region, and the long side of the bottom region and the long side of the long wall region are in contact with each other with their ends aligned; A second top surface region, located on the long side of the other long wall region opposite to the bottom surface region, wherein the dimension of the long side of the second top surface region is the same as the dimension of the long side of the bottom region, and the long side of the bottom region and the long side of the long wall region are in contact with each other with their ends aligned; A first short wall region is located on one short side of one of the long wall regions, the dimension of the long side of the first short wall region is the same as the dimension of the short side of the long wall region, and the short side of one of the long wall regions and the long side of the first short wall region are in contact with each other with their ends aligned; A second short wall region is located on the short side of the other long wall region on the side where the first short wall region is located, the dimension of the long side of the second short wall region is the same as the dimension of the short side of the long wall region, and the short side of the other long wall region and the long side of the second short wall region are in contact with each other with their ends aligned; The first top region and the second top region have a shape obtained by dividing the bottom region into two parts.The first short wall region and the second short wall region have a rectangular shape which is divided into two, with the length of the long side being the same as the length of the short side of the long wall region and the length of the short side being the same as the length of the short side of the bottom region. In the bending process, the end on the long side of the first top surface region and the end on the long side of the second top surface region are butted together or overlapped. In the welding process, the end on the long side of the first top surface region and the end on the long side of the second top surface region are welded together to form a first welded section and a top surface. In the bending process, the end on the long side of the first short wall region and the end on the long side of the second short wall region are butted together or overlapped. In the welding process, the end on the long side of the first short wall region and the end on the long side of the second short wall region are welded together to form a second welded section and a short wall. A method for manufacturing a sealed can body, wherein in the bending step, the ends on the short sides of the rectangular regions formed by the first top surface region and the second top surface region are butted together or overlapped with the ends on the short sides of the rectangular regions formed by the first short wall region and the second short wall region, and in the welding step, the ends on the short sides of the rectangular regions formed by the first and second top surface regions are welded together to form a third welded portion.

14. The method for manufacturing a sealed can body according to claim 13, wherein in the bending step, the ends on the short sides of the first short wall region and the rectangular region formed by the first short wall region are butted together or overlapped with the ends on the short sides of the bottom region, and in the welding step, the ends on the short sides of the first short wall region and the rectangular region formed by the first short wall region are welded together with the ends on the short sides of the bottom region to form a fourth welded portion.

15. The method for manufacturing a sealed can body according to claim 14, wherein the first short wall region and the second short wall region have a right-angled triangular shape, the dimensions of the short sides of the first short wall region and the second short wall region are the same as the dimensions of the short sides of the bottom region, the hypotenuse of the first short wall region and the hypotenuse of the second short wall region are parallel before the bending process, in the bending process the hypotenuse of the first short wall region and the hypotenuse of the second short wall region are butted together or overlapped, in the welding process the hypotenuse of the first short wall region and the hypotenuse of the second short wall region are welded together to form the second welded portion, and the second welded portion and the fourth welded portion are provided by continuous welding.

16. The method for manufacturing a sealed can according to claim 13, wherein the material metal plate further has a third short wall region provided on the short side of the bottom region, the boundary between the third short wall region and the bottom region extends from one end to the other on the short side of the bottom region, in the bending step the boundary between the third short wall region and the bottom region is made into a bent portion, the first short wall region and the second short wall region are provided with notches having a shape consistent with the third short wall region, in the bending step the end of the third short wall region and the end of the notch are butted together or overlapped, in the welding step the end of the third short wall region and the end of the notch are welded together to form a second A weld, and in the welding step the end on the long side of the first short wall region and the end on the long side of the second short wall region are welded together to form a second B weld.

17. A method for manufacturing a sealed can body according to any one of claims 13 to 16, wherein both the first short wall region and the second short wall region are made into a rectangular shape of the same shape, and in the welding process, the end on the long side of the first top region and the end on the long side of the second top region are welded at the center of the long sides of the two long wall regions to form the first welded portion.

18. A method for manufacturing a sealed can according to any one of claims 13 to 16, wherein the first top surface region and the first short wall surface region are arranged to be in contact with the same long wall surface region, the dimension of the short side of the first top surface region on the side of the first short wall surface region is made different from the dimension of the short side of the first short wall region on the side of the first top surface region, and the first welded portion and the second welded portion are separated in the welding process.

19. The method for manufacturing a sealed can according to any one of claims 13 to 16, wherein the dimensions of the short sides of the second top surface region on the side of the first short wall region and the second short wall region are the same as the dimensions of the short side of the bottom surface region, the dimensions of the short side of the first short wall region or the second short wall region joined to the short sides of the second top surface region on the side of the first short wall region and the second short wall region are the same as the dimensions of the short side of the bottom surface region, and in the welding process, the end of the first welded part is connected to one end of the third welded part, and the end of the second welded part is connected to the other end of the third welded part.

20. The material metal plate has relief portions provided in the first top surface region and the second top surface region, and / or relief portions provided in the first short wall region and the second short wall region, the relief portions provided in the first top surface region and the second top surface region have a shape that extends the first top surface region and the second top surface region along the long side direction of the first top surface region and the first top surface region, the relief portions provided in the first short wall region and the second short wall region have a shape that extends the first short wall region and the second short wall region along the long side direction of the first short wall region and the second short wall region, the welding process, the start point or end point of welding for forming the first weld and / or the second weld is set inside the relief portion, and the method for manufacturing the sealed can body further comprises a step of cutting off the relief portion after the welding process, as described in any one of claims 13 to 16.

21. The method for manufacturing a sealed container according to any one of claims 13 to 16, wherein the sealed container is a battery case.

22. A method for manufacturing a battery, comprising a method for manufacturing a sealed can body according to any one of claims 13 to 16.

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