Metal structure, housing, battery module, and battery pack

Abstract

This metal structure (M) comprises: a first metal member (M1) and a second metal member (M2); and a welding part (W) that joins a first end part (E1) of the first metal member (M1) in a prescribed direction side and a second end part (E2) of the second metal member (M2) in a different direction side that is not parallel to the prescribed direction, in a manner such that the first end part (E1) and the second end part (E2) are aligned with each other in the different direction. The welding part (W) on an opposite side of the first end part (E1) from the second end part (E2) extends to the edge of the first end part (E1) in the prescribed direction.

Description

Metal structure, housing, battery module and battery pack

[0001] The present invention relates to a metal structure, a housing, a battery module, and a battery pack.

[0002] In recent years, various battery packs have been developed. A battery pack includes a battery module and a housing that houses the battery module. A battery module includes battery cells and a housing that houses the battery cells.

[0003] Patent Document 1 describes laser welding of a copper plate and an aluminum plate, in which the copper plate and the aluminum plate are overlapped with each other, and the aluminum plate is irradiated with a laser.

[0004] Patent Document 2 describes laser welding of a copper plate and an aluminum plate, in which the copper plate and the aluminum plate are overlapped with each other and a laser is irradiated onto the copper plate.

[0005] JP 2018-12125 A JP 2020-66044 A

[0006] The ends of a plurality of metal members may be joined together by a weld. When the ends of a plurality of metal members are joined together by a weld, it may be necessary to improve the joining strength between the ends of the plurality of metal members.

[0007] One example of an object of the present invention is to improve the bonding strength between the ends of a plurality of metal members. Other objects of the present invention will become apparent from the description of this specification.

[0008] One aspect of the present invention is as follows: 1. A metal structure comprising: a plurality of metal members; and a weld that joins one end of one of the metal members on a side in a predetermined direction and another end of another of the metal members on a side in another direction non-parallel to the predetermined direction, with the one end and the other end aligned in the other direction, wherein the weld extends to an edge of the one end in the predetermined direction on the side opposite the one end to the other end. 2. The metal structure according to 1., wherein the weld has a penetration depth in the other direction. 3. The metal structure according to 2., wherein the weld is not present at an edge of the other end on the side in the predetermined direction. 4. The metal structure according to 1., wherein the weld has a penetration depth in the predetermined direction. 5. The metal structure according to any one of 1. to 4., wherein the weld is a laser weld. 6. A housing including the metal joined body according to any one of 1. to 5.. 7. A battery module comprising: a battery cell; and a housing for housing the battery cell, as set forth in 6. 8. A battery pack comprising: a battery module; and a housing for housing the battery module, as set forth in 6.

[0009] According to the above aspect of the present invention, the bonding strength between the ends of a plurality of metal members can be improved.

[0010] FIG. 2 is a perspective view of a metal structure according to an embodiment. FIG. 3 is a cross-sectional view taken along the line AA in FIG. 1. FIG. 4 is a cross-sectional view of a metal structure according to a comparative example. FIG. 5 is a scanning electron microscope (SEM) cross-sectional view of a metal structure M according to an example. FIG. 6 is a cross-sectional view of a metal structure according to a modified example. FIG. 7 is a perspective view of a battery module according to an embodiment. FIG. 8 is a perspective view of a plurality of battery cells housed inside a cell casing according to an embodiment. FIG. 9 is a top view of a battery pack according to an embodiment.

[0011] Hereinafter, embodiments and modifications of the present invention will be described with reference to the drawings. In all the drawings, like components are designated by like reference numerals, and descriptions thereof will be omitted as appropriate.

[0012] In this specification, unless otherwise specified, the term "metal" refers to not only pure metals but also alloys.

[0013] Fig. 1 is a perspective view of a metal structure M according to an embodiment of the present invention, and Fig. 2 is a cross-sectional view taken along the line AA in Fig. 1 .

[0014] For the purpose of explanation, directions D1, D2, and D3 are shown in Figures 1 and 2. The D1 direction is the extension direction from a first end E1 (described later) of a first metal member M1 (described later). The D2 direction is the extension direction from a second end E2 (described later) of a second metal member M2 (described later). The D1 and D2 directions are perpendicular to each other. The D3 direction is perpendicular to both the D1 and D2 directions. Therefore, the D1, D2, and D3 directions are non-parallel to each other. In Figure 2, the white circle with an X indicating the D3 direction indicates that the arrow pointing to the D3 direction is pointing into the paper.

[0015] Hereinafter, as necessary, the tip side of the arrow indicating the D1 direction will be referred to as the +D1 side, the opposite side of the tip of the arrow indicating the D1 direction will be referred to as the -D1 side, the tip side of the arrow indicating the D2 direction will be referred to as the +D2 side, the opposite side of the tip of the arrow indicating the D2 direction will be referred to as the -D2 side, the tip side of the arrow indicating the D3 direction will be referred to as the +D3 side, and the opposite side of the tip of the arrow indicating the D3 direction will be referred to as the -D3 side.

[0016] As shown in Figures 1 and 2, the metal structure M according to the embodiment includes a first metal member M1, a second metal member M2, and a welded portion W. As shown in Figure 1, the first metal member M1 has a generally plate shape perpendicular to the D2 direction, and the second metal member M2 has a generally plate shape perpendicular to the D1 direction. However, the shapes and orientations of the first metal member M1 and the second metal member M2 are not limited to the example shown in Figure 1. The first metal member M1 and the second metal member M2 may be made of the same metal or different metals. The first metal member M1 and the second metal member M2 are made of, for example, aluminum or an aluminum alloy.

[0017] 1 and 2, the first metal member M1 has a first end E1. The first end E1 is located on the -D1 side of the first metal member M1 in the D1 direction. The first metal member M1 has a thickness in the D2 direction of, for example, 1 mm or more and 10 mm or less. The first metal member M1 extends from the first end E1 in the D1 direction.

[0018] 1 and 2, the second metal member M2 has a second end E2. The second end E2 is located on the -D2 side of the second metal member M2 in the D2 direction. The second metal member M2 has a thickness in the D1 direction of, for example, 2 mm or more and 20 mm or less. The second metal member M2 extends in the D2 direction from the second end E2.

[0019] As shown in FIGS. 1 and 2, the first metal member M1 is arranged parallel to the D1 direction, and the second metal member M2 is arranged parallel to the D2 direction. Therefore, the first metal member M1 and the second metal member M2 are arranged non-parallel to each other. As shown in FIGS. 1 and 2, the first end E1 and the second end E2 are aligned in the D2 direction. The +D2 side of the first end E1 and the -D2 side of the second end E2 may be in contact with each other. Alternatively, the +D2 side of the first end E1 and the -D2 side of the second end E2 may be spaced apart with a gap between the +D2 side of the first end E1 and the -D2 side of the second end E2. As shown in FIGS. 1 and 2, when viewed from the D3 direction, the first metal member M1 and the second metal member M2 have a substantially right-angled corner formed by the first end E1 and the second end E2. Therefore, when viewed from the D3 direction, the metal structure M is substantially L-shaped. However, the corner formed by the first end E1 and the second end E2 is not limited to being a substantially right angle, and may be a corner greater than 0 degrees and less than 90 degrees, or a corner greater than 90 degrees and less than 180 degrees, with the +D1 side being 0 degrees when viewed from the D3 direction. In other words, when viewed from the D3 direction, the first end E1 and the second end E2 may be perpendicular or oblique.

[0020] The weld W joins the first end E1 and the second end E2 together. In the embodiment, the weld W is a laser weld having a penetration depth in the D2 direction. As shown in FIG. 2 , the end of the weld W on the +D2 side extends into the second end E2. The depth D of the portion of the weld W extending into the second end E2 is, for example, 0.1 mm or more and 10 mm or less. In laser welding to form the weld W, a laser beam is irradiated onto the side surface of the first end E1 on the -D2 side. The laser welding may be, for example, wobbling laser welding. In wobbling laser welding, the laser beam moves by combining a linear movement along the welding direction parallel to the D3 direction with a wobbling movement in a direction intersecting the welding direction. However, the laser beam may simply move linearly along the welding direction without the wobbling movement. In the example shown in FIG. 1 , the weld W has a weld bead extending in the D3 direction.

[0021] 2, the weld W extends from the −D2 side of the first end E1 to the edge of the first end E1 on the −D1 side in the D1 direction. By adjusting the irradiation position of the laser beam for laser welding to form the weld W, the weld W can be formed up to the edge of the first end E1 on the −D1 side in the D1 direction. For example, when viewed from the D2 direction, the center of the weld W in the D1 direction may be shifted toward the −D1 side with respect to the center of the second end E2 in the D1 direction.

[0022] As shown in FIG. 2 , no weld W is present on the edge of the second end E2 on the −D1 side in the D1 direction. Therefore, compared to when a weld W is present on the edge of the second end E2 on the −D1 side in the D1 direction, the resistance of the second end E2 to impacts received from the −D1 side can be improved. The width of the weld W in the D1 direction tends to decrease toward the +D2 side. Therefore, by adjusting the position of the weld W in the D1 direction and the depth of the weld W in the D2 direction, it is possible to eliminate the weld W from the edge of the second end E2 on the −D1 side in the D1 direction. However, a weld W may be present on the edge of the second end E2 on the −D1 side in the D1 direction.

[0023] 3 is a cross-sectional view of a metal structure MZ according to a comparative example. The metal structure MZ according to the comparative example is similar to the metal structure M according to the embodiment, except for the following points.

[0024] The metal structure MZ according to the comparative example has a welded portion WZ. The end of the welded portion WZ on the -D1 side in the D1 direction does not reach the edge of the first end E1 on the -D1 side in the D1 direction. Therefore, on both sides of the welded portion WZ of the first metal member M1 in the D1 direction, there are non-welded portions that have not been melted by welding. The end on the +D2 side of the welded portion WZ according to the comparative example extends into the second end E2. The width of the welded portion WZ in the D1 direction of the welded portion WZ according to the comparative example decreases as it moves toward the +D2 side.

[0025] The metal structure M according to the embodiment and the metal structure MZ according to the comparative example will be compared.

[0026] A metal structure MZ according to a comparative example will be described. In the metal structure MZ according to the comparative example, the width in the D1 direction of the portion on the -D2 side of the weld WZ is wider than the width in the D1 direction of the portion on the +D2 side of the weld WZ. Therefore, during cooling after welding to form the weld WZ, the shrinkage in the D1 direction of the portion on the -D2 side of the weld WZ is likely to be greater than the shrinkage in the D1 direction of the portion on the +D2 side of the weld WZ. Therefore, during cooling after welding to form the weld WZ, stress may be generated that causes the weld WZ and its surrounding area of ​​the first metal member M1 to warp convexly toward the +D2 side. During cooling after welding to form the weld WZ, heat is conducted from the weld WZ toward the +D1 side via the first metal member M1, and heat is conducted from the weld WZ toward the +D2 side via the second metal member M2. However, since the non-welded portion of the first metal member M1 on the -D1 side of the welded portion WZ of the first metal member M1 is almost entirely free of the metal constituting the first metal member M1, heat is less likely to be conducted from the welded portion WZ toward the -D1 side. Therefore, during cooling after welding to form the welded portion WZ, the portion on the -D1 side of the welded portion WZ is more likely to remain molten for a longer period of time than the portion on the +D1 side of the welded portion WZ. Therefore, during cooling after welding to form the welded portion WZ, the portion on the -D1 side of the welded portion WZ is more molten than the portion on the +D1 side of the welded portion WZ, which can generate the above-mentioned stress. This stress can cause cracks to form between the first end E1 and the second end E2 near the boundary between the welded portion WZ and the unmelted portion of the first metal member M1. In the structure shown in FIG. 3, these cracks occur most prominently on the +D1 side of the welded portion WZ.

[0027] The metal structure M according to the embodiment will now be described. As described above, in the metal structure M according to the embodiment, the weld W extends to the edge on the -D1 side of the first end E1 in the D1 direction on the -D2 side of the first end E1. Therefore, compared to the metal structure MZ according to the comparative example, where a non-welded portion of the first metal member M1 is present on the -D1 side of the weld WZ, the shrinkage of the weld W in the D1 direction makes it easier for the portion of the weld W on the -D1 side to move toward the +D1 side during cooling after welding to form the weld W. Therefore, in the metal structure M according to the embodiment, compared to the metal structure MZ according to the comparative example, the movement of the portion of the weld W on the -D1 side toward the +D1 side during cooling after welding to form the weld W can more easily relieve the above-mentioned stress. Therefore, in the embodiment, compared to the comparative example, it is possible to make it less likely for cracks to occur near the weld W between the first end E1 and the second end E2. Therefore, in the embodiment, the bonding strength of the first end E1 and the second end E2 can be improved compared to the comparative example, thereby improving the reliability and lifespan of the bonding portion between the first end E1 and the second end E2.

[0028] In the metal structure M according to the embodiment, the joint strength between the first end E1 and the second end E2 can be relatively high even when the +D2 side surface of the first end E1 and the −D2 side surface of the second end E2 are in contact with each other or when the +D2 side surface of the first end E1 and the −D2 side surface of the second end E2 are spaced apart. For example, even when the +D2 side surface of the first end E1 and the −D2 side surface of the second end E2 are in contact with each other or when the dimension in the D2 direction of the gap between the +D2 side surface of the first end E1 and the −D2 side surface of the second end E2 is greater than 0 and 0.5 mm or less, the shear strength of the first end E1 and the second end E2 can be 1,000 N or more per 10 mm of the length of the weld W in the D3 direction when the first end E1 and the second end E2 are made of an aluminum alloy.

[0029] FIG. 4 is a scanning electron microscope (SEM) cross-sectional view of the metal structure M according to the embodiment.

[0030] In the example shown in FIG. 4 , the first metal member M1 is an aluminum plate having a thickness of 3.0 mm in the D2 direction, and the second metal member M2 is an aluminum plate having a thickness of 5.0 mm in the D1 direction. The weld W was formed by wobbling laser welding. In wobbling laser welding, a laser beam was moved from the −D3 side toward the +D3 side by combining a linear movement along the welding direction parallel to the D3 direction with a wobbling movement in a direction intersecting the welding direction, and the laser beam was irradiated onto the −D2 side of the first end E1. By wobbling laser welding, the weld W has a weld bead extending in the D3 direction. The cross section shown in FIG. 4 shows a cross section of the end of the weld bead on the −D3 side.

[0031] As shown in FIG. 4, the weld W has a penetration depth in the D2 direction. The end of the weld W on the +D2 side extends into the second end E2. The weld W extends to the edge of the first end E1 on the -D1 side in the D1 direction on the -D2 side of the first end E1. In the example shown in FIG. 4, the weld W does not exist on the edge of the first end E1 on the -D1 side in the D1 direction on the +D2 side of the first end E1. The weld W does not exist on either edge of the second end E2 in the D1 direction.

[0032] 4, no cracks were observed between the first end E1 and the second end E2 on the -D1 side of the welded portion W. Therefore, it can be said that the joint strength between the first end E1 and the second end E2 can be improved by having the welded portion W extend to the edge of the first end E1 on the -D1 side in the D1 direction on the -D2 side of the first metal member M1.

[0033] 5 is a cross-sectional view of a metal structure MA according to a modified example. The metal structure MA according to the modified example is similar to the metal structure M according to the embodiment, except for the following points.

[0034] The welded portion WA according to the modified example joins the first end E1 and the second end E2 together. The welded portion WA according to the modified example is a laser welded portion having a penetration depth in the D1 direction. In the laser welding for forming the welded portion WA according to the modified example, a laser beam is irradiated onto the end face on the -D1 side of the first end E1 and the side face on the -D1 side of the second end E2. The laser welding may be, for example, wobbling laser welding.

[0035] The welded portion WA according to the modified example, like the welded portion W according to the embodiment, extends to the edge of the first end E1 on the -D1 side in the D1 direction on the -D2 side of the first end E1. Therefore, like the embodiment, the modified example can improve the joining strength of the first end E1 and the second end E2 compared to the comparative example.

[0036] Fig. 6 is a perspective view of a battery module 10 according to an embodiment. Fig. 7 is a perspective view of a plurality of battery cells 100 housed inside a cell housing 200 according to an embodiment.

[0037] 6 and 7 show the X, Y, and Z directions for the sake of explanation. The X direction indicates the front-to-rear direction of the battery module 10. The Y direction is perpendicular to the X direction. The Y direction indicates the left-to-right direction of the battery module 10. The Z direction is perpendicular to both the X and Y directions. The Z direction indicates the up-down direction of the battery module 10. The arrows pointing to the X direction, the Y direction, and the Z direction indicate the front, left, and up directions of the battery module 10, respectively. Hereinafter, as necessary, the tip side of the arrow indicating the X direction will be referred to as the +X side, the opposite side of the tip of the arrow indicating the X direction will be referred to as the −X side, the tip side of the arrow indicating the Y direction will be referred to as the +Y side, the opposite side of the tip of the arrow indicating the Y direction will be referred to as the −Y side, the tip side of the arrow indicating the Z direction will be referred to as the +Z side, and the opposite side of the tip of the arrow indicating the Z direction will be referred to as the −Z side. The relationship between the X direction, Y direction, and Z direction and the front-rear direction, left-right direction, and up-down direction of the battery module 10 is not limited to the above example.

[0038] The battery module 10 includes a plurality of battery cells 100 and a cell housing 200 .

[0039] As shown in Fig. 7 , the plurality of battery cells 100 are stacked in the Y direction. Hereinafter, where necessary, the plurality of battery cells 100 stacked alternately in the Y direction will be referred to as a stack of battery cells 100. The dimension of each battery cell 100 in the X direction is the dimension in the longitudinal direction of each battery cell 100. The dimension of each battery cell 100 in the Z direction is the dimension in the lateral direction of each battery cell 100. The dimension of each battery cell 100 in the Y direction is the dimension in the thickness direction of each battery cell 100. The shape of each battery cell 100 is not limited to this example.

[0040] Each battery cell 100 includes a battery element (not shown), an exterior material 102, a positive electrode tab 104, and a negative electrode tab 106. In one example, the battery element includes a plurality of positive electrodes and a plurality of negative electrodes (not shown) stacked alternately in the Y direction, and a separator (not shown) positioned between adjacent positive electrodes and negative electrodes in the Y direction. The exterior material 102 seals the battery element and an electrolyte (not shown). The positive electrode tab 104 is electrically connected to the positive electrode of the battery element. The positive electrode tab 104 is pulled out from one of both sides of the exterior material 102 in the X direction. The negative electrode tab 106 is electrically connected to the negative electrode of the battery element. The negative electrode tab 106 is pulled out from the other side of the exterior material 102 in the X direction. However, the structure of each battery cell 100 is not limited to this example.

[0041] Each battery cell 100 may be an all-solid-state battery. In an all-solid-state battery, a solid electrolyte layer is provided in a portion corresponding to a separator. An all-solid-state battery does not contain an electrolyte solution. Unless otherwise specified, the following description will be given assuming that each battery cell 100 is a battery cell containing an electrolyte solution.

[0042] The multiple battery cells 100 are electrically connected in a series-parallel combination. Specifically, cell groups including at least two battery cells 100 adjacent to each other in the Y direction and connected in parallel are stacked in the Y direction and connected in series. On the +X side of the stack of battery cells 100, a positive electrode tab 104 drawn from a battery cell 100 of one cell group connected in parallel and a negative electrode tab 106 drawn from a battery cell 100 of another cell group connected in parallel are electrically connected to each other, forming a tab group 108 including the positive electrode tab 104 and the negative electrode tab 106. The positive electrode tab 104 and the negative electrode tab 106 in the tab group 108 are joined to each other by, for example, laser welding. A tab group 108 is also located on the −X side of the stack of battery cells 100. Thus, multiple cell groups are connected in series from the cell group located at one end of the stack of battery cells 100 in the Y direction to the cell group located at the other end of the stack of battery cells 100 in the Y direction.

[0043] The electrical connection of the plurality of battery cells 100 is not limited to the above example. For example, a stack of battery cells 100 may be formed by connecting single battery cells 100 in series.

[0044] The cell casing 200 houses a stack of battery cells 100. The cell casing 200 has a first plate 210, a second plate 220, a third plate 230, a fourth plate 240, a fifth plate 250, and a sixth plate 260. The first plate 210 and the second plate 220 have a generally plate shape perpendicular to the X direction. The third plate 230 and the fourth plate 240 have a generally plate shape perpendicular to the Y direction. The fifth plate 250 and the sixth plate 260 have a generally plate shape perpendicular to the Z direction.

[0045] The first plate 210 covers the +X side portion of the stack of battery cells 100. The second plate 220 covers the -X side portion of the stack of battery cells 100. The third plate 230 covers the +Y side portion of the stack of battery cells 100. The fourth plate 240 covers the -Y side portion of the stack of battery cells 100. The fifth plate 250 covers the +Z side portion of the stack of battery cells 100. The sixth plate 260 covers the -Z side portion of the stack of battery cells 100.

[0046] 6 , the +Y side end of the fifth plate 250 and the +Z side end of the third plate 230 are joined to each other by a welded portion W. Therefore, in a state in which the cell housing 200 corresponds to the metal structure M, the fifth plate 250 corresponds to the first metal member M1, and the third plate 230 corresponds to the second metal member M2, as described for the metal structure M according to the embodiment, the +Y side end of the fifth plate 250 and the +Z side end of the third plate 230 can be joined to each other by a welded portion W. The same applies to the pair of the -Y side end of the fifth plate 250 and the +Z side end of the fourth plate 240.

[0047] The portion to which the weld W according to the embodiment can be applied is not limited to the example shown in FIG. 6 . For example, the +Y side end of the sixth plate 260 and the −Z side end of the third plate 230 may be joined to each other by a weld W. The same applies to the set of the −Y side end of the sixth plate 260 and the −Z side end of the fourth plate 240. The +Y side end of the first plate 210 and the +X side end of the third plate 230 may be joined to each other by a weld W. The same applies to the set of the −Y side end of the first plate 210 and the +X side end of the fourth plate 240, the set of the +Y side end of the second plate 220 and the −X side end of the third plate 230, and the set of the −Y side end of the second plate 220 and the −X side end of the fourth plate 240.

[0048] 8 is a top view of the battery pack 1 according to the embodiment. In FIG. 8, the white circle with a black dot indicating the Z direction indicates that the arrow indicating the Z direction is pointing towards the front of the page.

[0049] The battery pack 1 includes a plurality of battery modules 10 and a module housing 20 .

[0050] In the example shown in Fig. 8, four battery modules 10 are arranged in two rows and two columns in the X direction and the Y direction, respectively. However, the number and arrangement of the battery modules 10 are not limited to the example shown in Fig. 8. Each battery module 10 may be similar to the battery modules 10 described using Figs. 6 and 7.

[0051] The module housing 20 houses multiple battery modules 10. The module housing 20 has a lower plate 22 and side frames 24. The lower plate 22 has a generally plate shape perpendicular to the Z direction. When viewed from the Z direction, the lower plate 22 has a generally rectangular shape with a pair of sides generally parallel to the X direction and another pair of sides generally parallel to the Y direction. However, the shape of the lower plate 22 is not limited to the example shown in FIG. 8 . The multiple battery modules 10 are located on the +Z side of the +Z side surface of the lower plate 22. When viewed from the Z direction, the side frames 24 surround the multiple battery modules 10. The side frames 24 are located on the +Z side of the +Z side surface of the lower plate 22. The module housing 20 further has an upper plate (not shown) located on the +Z side of the multiple battery modules 10 and the side frames 24. The multiple battery modules 10 are covered by the upper plate.

[0052] As shown in FIG. 8 , the side frame 24 includes a first side plate 24a, a second side plate 24b, a third side plate 24c, and a fourth side plate 24d. When viewed from the Z direction, the first side plate 24a and the second side plate 24b extend along the +X side and the -X side of the lower plate 22, respectively. The first side plate 24a and the second side plate 24b have a generally plate shape perpendicular to the X direction. The third side plate 24c and the fourth side plate 24d extend along the +Y side and the -Y side of the lower plate 22, respectively. The third side plate 24c and the fourth side plate 24d have a generally plate shape perpendicular to the Y direction.

[0053] 8 , the +Y side end of the first side plate 24a and the +X side end of the third side plate 24c are joined to each other by a weld W. Therefore, with the module housing 20 corresponding to the metal structure M, the first side plate 24a corresponding to the first metal member M1, and the third side plate 24c corresponding to the second metal member M2, as described for the metal structure M according to the embodiment, the +Y side end of the first side plate 24a and the +X side end of the third side plate 24c can be joined to each other by a weld W. The same applies to the set of the -Y side end of the first side plate 24a and the +X side end of the fourth side plate 24d, the set of the +Y side end of the second side plate 24b and the -X side end of the third side plate 24c, and the set of the -Y side end of the second side plate 24b and the -X side end of the fourth side plate 24d.

[0054] Although the embodiments and modifications of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various configurations other than those described above can also be adopted.

[0055] This application claims priority based on Japanese Patent Application No. 2023-217959, filed December 25, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0056] REFERENCE SIGNS LIST 1 battery pack, 10 battery module, 20 module housing, 22 lower plate, 24 side frame, 24a first side plate, 24b second side plate, 24c third side plate, 24d fourth side plate, 100 battery cell, 102 exterior material, 104 positive electrode tab, 106 negative electrode tab, 108 tab group, 200 cell housing, 210 first plate, 220 second plate, 230 third plate, 240 fourth plate, 250 fifth plate, 260 sixth plate, E1 first end, E2 second end, M, MA, MZ metal structure, M1 first metal member, M2 second metal member, W, WA, WZ welded portion

Claims

1. A metal structure comprising: a plurality of metal members; a welding portion that joins one end portion on one side in a predetermined direction of one of the metal members and the other end portion on the other side in a direction non-parallel to the predetermined direction of the other metal member, with the one end portion and the other end portion arranged side by side in the other direction; and the welding portion existing up to the edge in the predetermined direction of the one end portion on the side opposite to the other end portion of the one end portion.

2. The metal structure according to claim 1, wherein the welding portion has a penetration depth in the other direction.

3. The metal structure according to claim 2, wherein the welding portion does not exist at the edge on the side in the predetermined direction of the other end portion.

4. The metal structure according to claim 1, wherein the welding portion has a penetration depth in the predetermined direction.

5. The metal structure according to any one of claims 1 to 4, wherein the welding portion is a laser welding portion.

6. A housing comprising the metal joint according to any one of claims 1 to 4.

7. A battery module comprising a battery cell and the housing according to claim 6 that houses the battery cell.

8. A battery pack comprising a battery module and the housing according to claim 6 that houses the battery module.

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