Battery module

Abstract

To provide a battery pack in which a large load is less likely to be locally applied to a part of a battery cell in a vertical direction when a plurality of battery cells are sandwiched between inner surfaces of a case.SOLUTION: A battery module includes a plurality of battery cells 17 stacked in a predetermined direction orthogonal to a vertical direction, and a plurality of resin frames 25 each located between two adjacent battery cells, and each resin frame includes an upper fitting section 31, a lower fitting section 31 located below the upper fitting section, an upper fitting groove 35 into which the upper fitting section can be fitted, and a lower fitting groove 35 located below the upper fitting groove and into which the lower fitting section can be fitted.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a battery module. [Background technology]

[0002] The following Patent Document 1 discloses a battery pack (energy storage device) including a battery stack having a plurality of battery cells (energy storage elements) stacked in a predetermined direction and a plurality of spacers positioned between adjacent battery cells, and a case that houses the battery stack. Both ends of the battery stack in the stacking direction are in contact with two points on the inner surface of the case. In other words, the battery stack is sandwiched between these two points. As a result, a load (constraint load) is applied from the case to each battery cell. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6891597 Summary of the Invention [Problem to be solved by the invention]

[0004] In the battery unit of Patent Document 1, there is a considerable difference between the magnitude of the load acting from the top of the case to the battery stack (battery cells) and the magnitude of the load acting from the bottom of the case to the battery stack (battery cells). If a larger load acts locally on one part of the vertical direction of each battery cell compared to other parts, the performance of each battery cell is likely to deteriorate.

[0005] In consideration of the above, the present invention aims to provide a battery module in which, when multiple battery cells are sandwiched between the inner surface of a case, a large load is unlikely to be applied locally to a portion of the battery cells in the vertical direction. [Means for solving the problem]

[0006] The battery module of the first embodiment comprises a plurality of battery cells stacked in a predetermined direction perpendicular to the vertical direction, and a plurality of resin frames positioned between each of two adjacent battery cells, each of the resin frames comprising an upper fitting portion, a lower fitting portion positioned below the upper fitting portion, an upper fitting groove into which the upper fitting portion can fit, and a lower fitting groove positioned below the upper fitting groove into which the lower fitting portion can fit.

[0007] The battery module of the first aspect includes a plurality of battery cells stacked in a predetermined direction perpendicular to the vertical direction, and a plurality of resin frames positioned between each pair of adjacent battery cells. Therefore, when this battery module is placed inside a box-shaped case and is brought into contact with the inner surface of the case at two points facing each other in the predetermined direction, a restraint load is applied to the battery stack from these two points.

[0008] Each resin frame of the battery module of the first embodiment includes an upper fitting portion, a lower fitting portion located below the upper fitting portion, an upper fitting groove into which the upper fitting portion can fit, and a lower fitting groove located below the upper fitting groove and into which the lower fitting portion can fit. Therefore, the upper fitting portion of one of two adjacent resin frames fits into the upper fitting groove of the other, and the lower fitting portion of one fits into the lower fitting groove of the other. Therefore, when a restraint load is applied to the battery stack from the two locations on the case, the load applied from each resin frame to adjacent battery cells tends to be uniform across each vertical portion of the battery cells. In other words, in the battery module of the first embodiment, when multiple battery cells are sandwiched between the inner surfaces of the case, a large load is unlikely to be applied locally to a portion of the battery cells in the vertical direction.

[0009] The battery module of the second aspect is the battery module of the first aspect, wherein each of the resin frames includes an elongated fitting portion that includes the upper fitting portion and the lower fitting portion and extends in the vertical direction, and an elongated fitting groove that includes the upper fitting groove and the lower fitting groove, extends in the vertical direction, and is capable of fitting with the elongated fitting portion.

[0010] In the battery module of the second aspect, the elongated fitting portions and elongated fitting grooves of two adjacent resin frames fit together over a large area in the vertical direction, which reduces the risk of a large load being applied locally to a portion of the battery cells in the vertical direction when the battery cells are sandwiched between the inner surfaces of the case.

[0011] The battery module of the third aspect is the same as that of the first or second aspect, in which the upper fitting portion, the lower fitting portion, the upper fitting groove, and the lower fitting groove are respectively provided on both sides of each resin frame in a direction perpendicular to the predetermined direction.

[0012] In the battery module of the third aspect, an upper fitting portion, a lower fitting portion, an upper fitting groove, and a lower fitting groove are provided on both sides of each resin frame in a direction perpendicular to the predetermined direction. Therefore, in the battery module of the third aspect, when multiple battery cells are sandwiched between the inner surface of the case, there is less risk of a large load being applied locally to a portion of the battery cells in the vertical direction.

[0013] The battery module of the fourth aspect is the same as that of the third aspect, and each resin frame is provided on both sides with a pair of inner side walls having the upper and lower fitting grooves on their outer surfaces, and a pair of outer side walls having the upper and lower fitting portions on their inner surfaces.

[0014] In the battery module of the fourth aspect, upper and lower fitting grooves provided on the inner sidewall of one of two adjacent resin frames are fitted with upper fitting portions and lower fitting portions provided on the outer sidewall of the other. Therefore, in the battery module of the fourth aspect, the fitted state between the upper fitting portions and the upper fitting groove, and the fitted state between the lower fitting portions and the lower fitting groove, are difficult to release. Furthermore, in the battery module of the fourth aspect, when sandwiched between the inner surfaces of multiple battery cell cases, the two adjacent resin frames are prevented from shifting in a direction perpendicular to a predetermined direction.

[0015] The battery module of the fifth aspect is any one of the first to fourth aspects, wherein each of the resin frames comprises an upper first connection portion located between the both side portions, a lower first connection portion located between the both side portions and lower than the upper first connection portion, an upper second connection portion located between the both side portions and engageable with the ceiling surface of the upper first connection portion from below, and a lower second connection portion located between the both side portions and engageable with the top surface of the lower first connection portion.

[0016] In the battery module of the fifth aspect, the upper second connection portion of one of two adjacent resin frames engages from below with the ceiling surface of the upper first connection portion of the other, and the lower second connection portion of one of the two adjacent resin frames engages with the top surface of the lower first connection portion of the other. Therefore, in the battery module of the fifth aspect, when sandwiched between the inner surfaces of the multiple battery cell cases, the two adjacent resin frames are prevented from shifting vertically relative to each other. [Effects of the Invention]

[0017] As described above, the battery module according to the present invention has the excellent effect of preventing a large load from being locally applied to a portion of the battery cells in the vertical direction when multiple battery cells are sandwiched between the inner surface of the case. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is an exploded perspective view of a battery pack including a battery module according to an embodiment. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. 10 is a perspective view showing a state in which two resin frames are connected to support one battery cell. [Figure 5] FIG. 5 is a schematic cross-sectional view taken along the arrow line 5-5 in FIG. 4. [Figure 6] FIG. 6 is a schematic cross-sectional view taken along the arrow line 6-6 in FIG. 4. [Figure 7] FIG. 2 is a schematic plan view of a portion of the battery pack. [Figure 8] FIG. 10 is a perspective view of a resin frame according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0019] A battery pack 10 including a battery module 12 according to an embodiment will be described below with reference to the accompanying drawings. Note that the arrows UP, FR, and LH in each drawing indicate the upper side in the up-down direction, the front side in the front-to-back direction, and the left side in the left-to-right direction, respectively.

[0020] The battery pack 10 of this embodiment is mounted on, for example, a vehicle. The electric power generated by the battery pack 10 is supplied to, for example, an electric motor that is a drive device of the vehicle. Note that the battery pack 10 may also be mounted on a device other than a vehicle.

[0021] As shown in FIG. 1, the battery pack 10 includes two battery modules 12 (only one of which is shown in FIG. 1) and a battery case 60.

[0022] Each battery module 12 includes a battery stack 15, a shim 52, a bus bar, and a cooling member.

[0023] The battery stack 15 includes a plurality of battery cells 17 arranged in the front-to-rear direction (a predetermined direction), a plurality of insulating resin frames 25 provided between adjacent battery cells 17, and a pair of front and rear end plates 50. Each battery cell 17 includes a substantially rectangular parallelepiped cell body 18 and a pair of terminals 19 (see FIGS. 1 and 4) extending upward from the top surface of the cell body 18. The battery stack 15 may include any number of battery cells 17 and resin frames 25 as long as there is more than one.

[0024] 2 and 3, the resin frame 25, which is an integrally molded resin product, includes a partition plate portion 27, an outer sidewall 29, a long fitting portion 31, an inner sidewall 33, an upper first connecting portion 37, an upper second connecting portion 38, a bottom plate portion 40, a rib 41, a lower first connecting portion 43, and a lower second connecting portion 44. The resin frame 25 is elastically deformable. The resin frame 25 is made of, for example, polypropylene.

[0025] The partition plate portion 27 is a rectangular flat plate that is long in the left-right direction perpendicular to the front-rear direction. The rear ends of the outer side walls 29 are fixed to both left-right sides (direction perpendicular to the predetermined direction) of the front surface of the partition plate portion 27. The front ends of the inner side walls 33 are fixed to both left-right sides of the rear surface of the partition plate portion 27. The left inner side wall 33 is located to the right of the left outer side wall 29, and the right inner side wall 33 is located to the left of the right outer side wall 29. The lower ends of the partition plate portion 27, the outer side wall 29, and the inner side wall 33 are located at the same position, and the upper ends of the partition plate portion 27, the outer side wall 29, and the inner side wall 33 are located at the same position. The side shapes of the left and right outer side walls 29 are rectangular and long in the up-down direction. The inner surfaces (opposing surfaces) of the left and right outer side walls 29 are provided with elongated fitting portions 31 that protrude inward and extend in the up-down direction. The elongated fitting portion 31 is provided across the entire vertical direction of the outer side wall 29. The upper portion, including the upper end of the elongated fitting portion 31, corresponds to the "upper fitting portion," and the lower portion, including the lower end of the elongated fitting portion 31, corresponds to the "lower fitting portion." As shown in FIG. 3 , the cross-sectional shape (planar shape) of the elongated fitting portion 31 when cut along a horizontal plane is an approximately right-angled triangle. The side shapes of the left and right inner side walls 33 are rectangles that are long in the vertical direction. An elongated fitting groove 35 extending in the vertical direction is formed on the outer surface of the left and right inner side walls 33. The elongated fitting groove 35 is provided across the entire vertical direction of the inner side wall 33. In other words, both the upper and lower ends of the elongated fitting groove 35 are open. The upper portion, including the upper end of the elongated fitting groove 35, corresponds to the "upper fitting groove," and the lower portion, including the lower end of the elongated fitting groove 35, corresponds to the "lower fitting groove." As shown in FIG. 3, the cross-sectional shape (planar shape) of the elongated fitting groove 35 when cut along a horizontal plane is a right triangle, which is substantially the same as the cross-sectional shape of the elongated fitting portion 31.

[0026] Furthermore, an upper first connection portion 37 and an upper second connection portion 38 are fixed to the left-right center of the upper edge of the partition plate portion 27. The upper first connection portion 37 extends rearward from the upper surface of the partition plate portion 27, and the upper second connection portion 38 extends forward from the upper surface of the partition plate portion 27. The front shapes of the upper first connection portion 37 and the upper second connection portion 38 are both approximately U-shaped. However, the vertical dimension of the upper second connection portion 38 is smaller than that of the upper first connection portion 37, and the left-right dimension of the upper second connection portion 38 is smaller than that of the upper first connection portion 37.

[0027] 3, the outer peripheral edge of the bottom plate 40 is fixed to the lower part of the rear surface of the partition plate 27 and to the lower parts of the inner surfaces of the left and right inner side walls 33. The bottom plate 40 has a rectangular planar shape. Furthermore, a plurality of ribs 41 extending rearward are provided on the rear surface of the partition plate 27. The rear ends of each rib 41 are located forward of the rear ends of the inner side walls 33 and the bottom plate 40.

[0028] 2, 3, and 6, a lower first connection portion 43 and a lower second connection portion 44 are provided at the lower part of the partition plate portion 27. The lower first connection portion 43 and the lower second connection portion 44 are located below the bottom plate portion 40. The front edges of the pair of left and right lower first connection portions 43 are fixed to a portion located slightly above the lower edge of the rear surface of the partition plate portion 27. The left and right lower first connection portions 43 have a rectangular planar shape. The rear edges of the pair of left and right lower second connection portions 44 are fixed to the lower edge of the front surface of the partition plate portion 27. The left and right lower second connection portions 44 have a rectangular planar shape. As shown in FIG. 6, the left and right lower second connection portions 44 are located slightly above the left and right lower first connection portions 43. Furthermore, in a planar view, the lower first connection portion 43, the lower second connection portion 44, the upper first connection portion 37, and the upper second connection portion 38 are located between the left and right inner side walls 33.

[0029] As shown in FIG. 4, one battery cell 17 is arranged between two resin frames 25 adjacent in the front-to-rear direction. As shown in FIG. 6, the lower end of the battery cell 17 is placed on the bottom plate portion 40 of the front of the two resin frames 25. Hereinafter, as shown in FIGS. 4 to 6, this resin frame 25 will be referred to as resin frame 25F. As a result, the battery cell 17 is positioned between the left and right inner side walls 33 of the resin frame 25F, and the front surface of the battery cell 17 contacts the rear ends of each rib 41 of the resin frame 25F. In this state, the rear of the two resin frames 25 is moved toward the resin frame 25F from behind. Hereinafter, this resin frame 25 will be referred to as resin frame 25R.

[0030] When the resin frame 25R is moved forward relative to the resin frame 25F, the left and right outer side walls 29 of the resin frame 25R are elastically deformed outward, and the inclined surfaces 31RS of the left and right elongated fitting portions 31 contact the rear ends of the left and right inner side walls 33 of the resin frame 25R, respectively. When the resin frame 25R is moved forward relative to the resin frame 25F in this state, the left and right elongated fitting portions 31 of the resin frame 25R fit into the left and right elongated fitting grooves 35 of the resin frame 25F, and the left and right outer side walls 29 of the resin frame 25R elastically return inward. Furthermore, as shown in FIG. 5, the upper second connecting portion 38 of the resin frame 25R enters the internal space of the upper first connecting portion 37 of the resin frame 25F. Furthermore, as shown in FIG. 6, the left and right lower second connecting portions 44 of the resin frame 25R move directly above the left and right lower first connecting portions 43 of the resin frame 25F. At this time, the upper surface of the upper second connection portion 38 of the resin frame 25R contacts the ceiling surface of the upper first connection portion 37 of the resin frame 25F from below, and the left and right lower second connection portions 44 of the resin frame 25R elastically deform upward and contact the upper surfaces of the left and right lower first connection portions 43 of the resin frame 25F.

[0031] As a result, as shown in Figure 4, the front and rear surfaces, left and right surfaces, and bottom surface of one battery cell 17 are covered by the integrated resin frames 25F and 25R, and the upper first connection portion 37 and upper second connection portion 38 face the top surface of the battery cell 17. Furthermore, the rib 41 of the resin frame 25F contacts the front surface of the battery cell 17, and the front surface of the partition plate portion 27 of the resin frame 25R contacts the rear surface of the battery cell 17. In this way, the battery cell 17 is housed within two resin frames 25 lined up in front and behind.

[0032] Furthermore, in the same manner, all of the battery cells 17 are housed in two resin frames 25 arranged in a front-to-back manner. That is, as shown in Figure 7, multiple battery cells 17 and resin frames 25 that are integrated with each other are stacked in the front-to-rear direction.

[0033] As shown in FIG. 1 , the battery case 60 has an open top and a rectangular parallelepiped shape. The battery case 60 includes a bottom plate 61 whose planar shape is a rectangle elongated in the front-to-rear direction, a front wall 62 extending upward from the front edge of the bottom plate 61, a rear wall 63 extending upward from the rear edge of the bottom plate 61, and a pair of left and right side walls 64 extending upward from both left and right sides of the bottom plate 61. The front edges of the left and right side walls 64 are connected to the left and right sides of the front wall 62, respectively, and the rear edges of the left and right side walls 64 are connected to the left and right sides of the rear wall 63, respectively. Furthermore, the lower edge of a partition plate 66 parallel to the side walls 64 is connected to the center of the top surface of the bottom plate 61 in the left-to-right direction. The front edge of the partition plate 66 is fixed to the front surface of the front wall 62, and the rear edge of the partition plate 66 is fixed to the rear surface of the rear wall 63. That is, the partition plate 66 divides the internal space of the battery case 60 into a pair of left and right storage spaces 68 .

[0034] Two battery stacks 15 are inserted into the left and right storage spaces 68 of the battery case 60. Furthermore, as shown in FIG. 7 , the front end plate 50 is inserted between the outer side wall 29 of the resin frame 25 at the front end of the battery stack 15 and the partition plate portion 27, and the rear end plate 50 is inserted into the storage space 68 so as to contact the rear surface of the rear-end battery cell 17. Furthermore, a shim 52 is inserted between the rear end plate 50 and the rear wall portion 63. As a result, the front end plates 50 of the left and right battery stacks 15 press against the rear surface of the front wall portion 62, and the shim 52 presses against the front surface of the rear wall portion 63. In other words, the left and right battery modules 12 are sandwiched between the front wall portion 62 and the rear wall portion 63 of the battery case 60 in the front-rear direction. That is, a restraining load is applied to the left and right battery modules 12 in the front-rear direction from the front wall portion 62 and the rear wall portion 63.

[0035] Furthermore, a bus bar is connected to the terminal 19 of each battery cell 17. Furthermore, cooling members located above the battery modules 12 are provided in the left and right storage spaces 68, respectively. The left and right cooling members cool the left and right battery modules 12 (battery cells 17), respectively. The cool air emitted by the cooling members can move up and down through the spaces formed between adjacent ribs 41, for example.

[0036] (Action and effect) Next, the operation and effects of the embodiment will be described.

[0037] In the battery pack 10 of the embodiment configured as described above, as described above, a restraining load in the front-to-rear direction is applied to the left and right battery modules 12 from the front wall 62 and rear wall 63 of the battery case 60. Because the top surface of the battery case 60 is open, the amount of forward deformation of the upper part of the front wall 62 at this time is likely to be greater than the amount of forward deformation of the lower part of the front wall 62, and the amount of rearward deformation of the upper part of the rear wall 63 is likely to be greater than the amount of rearward deformation of the lower part of the rear wall 63. Therefore, there is a considerable difference between the magnitude of the load applied to the battery modules 12 from the upper parts of the front wall 62 and rear wall 63 and the magnitude of the load applied to the battery modules 12 from the lower parts of the front wall 62 and rear wall 63.

[0038] However, each resin frame 25 includes an elongated fitting portion 31 extending in the vertical direction and an elongated fitting groove 35 extending in the vertical direction into which the elongated fitting portion 31 can fit. Therefore, the elongated fitting portions 31 and the elongated fitting grooves 35 of two adjacent resin frames 25 fit together over a large vertical area. Therefore, when a restraining load in the front-to-rear direction is applied to the battery module 12 from the front wall portion 62 and the rear wall portion 63 of the battery case 60, the load applied from each resin frame 25 to the adjacent battery cells 17 tends to be uniform across all vertical portions of the battery cells 17. That is, in the battery module 12, when multiple battery cells 17 are sandwiched between the front wall portion 62 and the rear wall portion 63 of the battery case 60, a large load is unlikely to be applied locally to a portion of each battery cell 17 in the vertical direction. Therefore, the performance of each battery cell 17 is unlikely to be degraded.

[0039] Furthermore, each resin frame 25 has a pair of outer side walls 29 with elongated fitting portions 31 on the inner surface thereof and a pair of inner side walls 33 with elongated fitting grooves 35 on the outer surface thereof, on both the left and right sides thereof. Therefore, compared to when the resin frame 25 has elongated fitting portions 31 and elongated fitting grooves 35 on only one side thereof, there is less risk of a large load being applied locally to a portion of the battery cell 17 in the vertical direction.

[0040] Furthermore, the outer side walls 29 provided on both left-right sides of one of two adjacent resin frames 25 face from the outside to the inner side walls 33 provided on both sides of the other, and the elongated fitting portions 31 provided on each outer side wall 29 fit into the elongated fitting grooves 35 provided in each inner side wall 33. This prevents the two adjacent resin frames 25 from shifting left-right relative to each other. Furthermore, the fitted state between the elongated fitting portions 31 and the elongated fitting grooves 35 of the adjacent resin frames 25 is difficult to release.

[0041] Furthermore, the outer side walls 29 and inner side walls 33 on both sides of each resin frame 25 cover the sides of the battery cells 17, preventing the battery cells 17 located between adjacent resin frames 25 from moving sideways relative to the resin frames 25.

[0042] Furthermore, the top surface of the upper second connection portion 38 of one of two adjacent resin frames 25 contacts the ceiling surface of the upper first connection portion 37 of the other from below, and the left and right lower second connection portions 44 of one of the frames elastically deform upward and contact the top surfaces of the left and right lower first connection portions 43 of the other frame. This prevents the two adjacent resin frames 25 from being misaligned in the up and down direction.

[0043] Furthermore, the elongated fitting portion 31, the elongated fitting groove 35, the upper first connection portion 37, the upper second connection portion 38, the lower first connection portion 43, and the lower second connection portion 44 function to position the two adjacent resin frames 25 in the up-down and left-right directions. Therefore, there is no risk of the load from the resin frames 25 being unevenly applied to the battery cells 17 due to misalignment of the two adjacent resin frames 25 in the up-down or left-right directions.

[0044] The battery module 12 according to the embodiment has been described above, but the design thereof can be appropriately modified within the scope of the gist of the present invention.

[0045] For example, as in the modified resin frame 25A shown in Fig. 8, the left and right outer side walls 29 may include upper fitting portions 31U and lower fitting portions 31D that are vertically spaced from each other, and the left and right inner side walls 33 may have upper fitting grooves 35U and lower fitting grooves 35D that are vertically spaced from each other. In this modified example, the left and right lower fitting portions 31D of one (front) of two adjacent resin frames 25A fit into the left and right lower fitting grooves 35D of the other (rear), and the left and right upper fitting portions 31U of one fit into the left and right upper fitting grooves 35U of the other. Even in this modified example, when a restraining load in the front-to-rear direction is applied to the battery module 12 from the front wall portion 62 and rear wall portion 63 of the battery case 60, the load applied from each resin frame 25A to adjacent battery cells 17 tends to be uniform across all vertical positions of the battery cells 17.

[0046] The number of battery modules 12 (battery stacks 15) housed in one battery case 60 may be one, or may be three or more.

[0047] The upper first connecting portion 37, the upper second connecting portion 38, the lower first connecting portion 43, and the lower second connecting portion 44 may be omitted from the resin frames 25, 25A.

[0048] The shim 52 may be omitted from the battery pack 10. [Explanation of symbols]

[0049] 12 Battery Module 17 Battery Cells 25 25A Resin frame 29 Outer side wall 31 Long fitting portion (upper fitting portion) (lower fitting portion) 31U upper fitting part 31D Lower fitting part 33 Inner sidewall 35 Long fitting groove (upper fitting groove) (lower fitting groove) 35U upper fitting groove 35D Lower fitting groove 37 Upper first connection 38 Upper second connection 43 Lower first connection part 44 Lower second connection part 50 End Plate 52 Sim

Claims

1. a plurality of battery cells stacked in a predetermined direction perpendicular to the up-down direction; a plurality of resin frames positioned between each pair of adjacent battery cells; Equipped with Each of the resin frames is an upper fitting portion; a lower fitting portion located below the upper fitting portion; an upper fitting groove into which the upper fitting portion can be fitted; a lower fitting groove located below the upper fitting groove and into which the lower fitting portion can be fitted; A battery module comprising:

2. Each of the resin frames is an elongated fitting portion including the upper fitting portion and the lower fitting portion and extending in the up-down direction; an elongated fitting groove including the upper fitting groove and the lower fitting groove, extending in the vertical direction and capable of fitting with the elongated fitting portion; The battery module according to claim 1 .

3. 3. The battery module according to claim 1, wherein the upper fitting portion, the lower fitting portion, the upper fitting groove, and the lower fitting groove are respectively provided on both sides of each of the resin frames in a direction perpendicular to the predetermined direction.

4. On both sides of each of the resin frames, a pair of inner side walls having the upper and lower fitting grooves on their outer surfaces; a pair of outer side walls having the upper fitting portion and the lower fitting portion provided on their inner surfaces; The battery module according to claim 3 , further comprising:

5. Each of the resin frames is an upper first connection portion located between the side portions; a lower first connection portion located between the both side portions and below the upper first connection portion; an upper second connection portion located between the both side portions and engageable with a ceiling surface of the upper first connection portion from below; a lower second connection portion located between the both side portions and engageable with an upper surface of the lower first connection portion; The battery module according to claim 3 .

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