Battery case

Abstract

To provide a battery case that can easily position a battery cell in the height direction, thereby enabling efficient connection work between connection terminals and conductive members and preventing a decrease in connection quality.SOLUTION: A battery case includes a first frame in which a plurality of first accommodating holes are formed, each capable of accommodating one end of a battery cell having a connection terminal at one end, and a second frame in which a plurality of second accommodating holes are formed, each capable of accommodating the other end of the battery cell, the first accommodating holes and the second accommodating holes forming an accommodating chamber in which the battery cell can be accommodated, and the second accommodating holes have a positioning portion that positions the other end of the battery cell in the accommodation direction, and the positioning portion is a protrusion formed around the entire circumference of the lower end of the second accommodating hole so as to protrude towards the inside of the second accommodating hole.SELECTED DRAWING: Figure 5A

Description

[Technical Field]

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

[0002] There is a battery module in which a large number of battery cells are housed in a battery case and conductive members are connected to the connection terminals of the battery cells. Patent Document 1 discloses a cooling structure that dissipates heat by bringing a thermally conductive material into contact between the battery cells and a cooling plate for cooling purposes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2023-524698 Summary of the Invention [Problem to be solved by the invention]

[0004] When multiple battery cells are housed in a battery case, there is a possibility that the height positions of the battery cells may vary. This causes variations in the thermal conductivity between the bottom surface of the battery cells and the cooling plate, which can result in poorer cooling quality for some battery cells than for the others.

[0005] The present disclosure aims to provide a battery case that can suppress variations in the height direction position of battery cells and suppress deterioration in the cooling quality of the bottom surface of the battery cells. [Means for solving the problem]

[0006] The battery case of the present disclosure has a first frame in which a plurality of first accommodating holes are formed that can accommodate one end of a battery cell having a connection terminal at one end, and a second frame in which a plurality of second accommodating holes are formed that can accommodate the other end of the battery cell, and the first accommodating holes and the second accommodating holes form an accommodating chamber that can accommodate the battery cell, and the second accommodating holes have a positioning portion that positions the other end of the battery cell in the accommodation direction, and the positioning portion is a protrusion formed around the entire circumference of the lower end of the second accommodating hole so as to protrude toward the inside of the second accommodating hole. [Effects of the Invention]

[0007] In the present disclosure, by positioning the lower end of the battery cell in the second housing hole of the second frame, the height of the bottom surface of the battery cell is aligned with the battery case, thereby preventing a decrease in the cooling quality of the bottom surface of the battery cell. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a diagram showing the appearance of a battery module. [Figure 2] FIG. 2 is an exploded view of the battery module. [Figure 3] FIG. 2 is a further exploded view of the battery module. [Figure 4] FIG. 3 is a partially cutaway perspective cross-sectional view of a second frame. [Figure 5A] FIG. 2 is an enlarged view of the second frame. [Figure 5B] FIG. 2 is an enlarged view of the second frame. [Figure 6A] FIG. 10 is an enlarged view of a first modified example of the second frame. [Figure 6B] FIG. 10 is an enlarged view of a first modified example of the second frame. [Figure 7A] FIG. 10 is an enlarged view of a second modified example of the second frame. [Figure 7B] FIG. 10 is an enlarged view of a second modified example of the second frame. [Figure 8A] FIG. 10 is an enlarged view of a third modified example of the second frame. [Figure 8B]FIG. 10 is an enlarged view of a third modified example of the second frame. [Figure 9A] FIG. 10 is an enlarged view of a fourth modified example of the second frame. [Figure 9B] FIG. 10 is an enlarged view of a fourth modified example of the second frame. [Figure 10] FIG. 10 is an exploded view showing a conventional battery module. [Figure 11A] FIG. 1 is a diagram showing the appearance of a conventional battery module. [Figure 11B] FIG. 10 is a partially enlarged view of a conventional battery module. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that each of the embodiments described below represents a specific example of the present disclosure. Therefore, the components, the arrangement positions and connection forms of the components, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components not recited in independent claims will be described as optional components.

[0010] Furthermore, each drawing is a schematic diagram and is not necessarily an exact illustration. In each drawing, substantially the same components are denoted by the same reference numerals, and redundant explanations will be omitted or simplified.

[0011] First, a comparative example of a battery module 100 will be described. A battery module has a battery case that houses a large number of battery cells, and conductive members are connected to the connection terminals of the battery cells. Fig. 10 shows an exploded view of the main parts of a conventional battery module 100. Fig. 11A shows the external appearance of the battery module 100, and Fig. 11B is a partially enlarged view of the same. Note that some components are not shown.

[0012] The battery cells 103 are housed in a battery case 102 having a first frame 110 and a second frame 120. A number of first housing holes 111 and a number of second housing holes 121 are formed in the first frame 110 and the second frame 120, respectively, so as to face each other, and the first housing holes 111 and the second housing holes 121 form housing chambers for the battery cells 103.

[0013] The upper portion 105 of the battery cell 103 is housed in the first housing hole 111, and the lower portion of the battery cell 103 is housed in the second housing hole 121, so that the battery cell 103 is fixed and housed in the battery case 102.

[0014] Bus bar 140, which serves as a conductive member, is provided on the upper surface of first frame 110, and connection pieces 142 formed to protrude laterally from main body 141 are overlapped with connection terminals 104 of battery cells 103 and joined by laser welding or the like. Note that, in the illustrated example, bus bar 140 and connection terminals 104 are joined by connection pieces 142, but main body 141 of bus bar 140 and connection terminals 104 may also be connected by wire bonding.

[0015] When assembling the battery module 100, the second frame 120 is placed on a mounting base with the second accommodating holes 121 facing upward, the battery cells 103 are accommodated in the second accommodating holes 121 with their connection terminals 104 facing upward, and the first frame 110 is placed and joined on the second frame 120 with its first accommodating holes 111 facing downward so that the upper portions 105 of the battery cells 103 are accommodated in the first accommodating holes 111.

[0016] Next, bus bar 140 is attached onto first frame 110, and connection pieces 142 are bonded to connection terminals 104. Then, a potting agent (not shown) is applied to cover bus bar 140, and then a top cover (not shown) is placed over it. Furthermore, cooling plate 152 is bonded to the bottom of second frame 120 with adhesive 151.

[0017] Because the bus bar 140 is formed by pressing a plate-shaped member or the like, the heights of the numerous connection pieces 142 are approximately the same. When joining the connection pieces 142 to the connection terminals 104, if the heights of the connection terminals 104 of the multiple battery cells 103 are not the same, gaps may form between some of the connection pieces 142 and the connection terminals 104.

[0018] In Figure 11B, the right-hand battery cell 103 is of an appropriate height and is inserted all the way into the first accommodating hole 111 (all the way to the top in the figure), so the connection piece 142 and the connection terminal 104 are in proper contact, whereas the left-hand battery cell 103' is at a lower position than the right-hand battery cell 103 and is not inserted all the way into the first accommodating hole 111', so a gap G is created between the connection piece 142' and the connection terminal 104'.

[0019] In order to join the connection piece 142' and the connection terminal 104', the process becomes complicated, requiring the battery cell 103' to be lifted up while joining, or the connection piece 142' to be pressed down while joining, which reduces the efficiency of the joining work. Furthermore, even if joining is possible, there are problems such as internal stress remaining in the connection piece 142', which reduces the quality of the joining.

[0020] FIG. 1 shows the appearance of a battery module 1 according to the present disclosure, and FIG. 2 is an exploded view of the battery module 1. The battery module 1 houses a large number of battery cells 3 in a resin battery case 2. The battery case 2 has a first frame 10 and a second frame 20, which form a chamber for housing the battery cells 3 inside. A bus bar 40 is attached to the upper surface of the first frame 10 and is connected to the connection terminals of the battery cells 3. The bus bar 40 is covered with a potting material (not shown), and a top cover 50 is further provided thereon, covering the upper surfaces of the first frame 10 and the bus bar 40. A cooling plate 52 is bonded to the lower surface of the second frame 20 with adhesive 51. The lower surfaces of the battery cells 3 are exposed from the bottom of the second frame 20 and are connected to the cooling plate 52 via adhesive 51.

[0021] 3 is an exploded view showing the battery case 2 of the battery module 1. The second frame 20 is a container-like member with an open top and formed with a large number of second accommodating holes 23 that accommodate the lower portions of the battery cells 3. The second frame 20 houses a heat insulating material 38 with a large number of through holes 39 formed therein through which the battery cells 3 pass. The battery cells 3 are inserted into the through holes 39 so that their lower portions are housed in the second accommodating holes 23 and their middle portions are surrounded by the heat insulating material 38.

[0022] The first frame 10 is formed with a first accommodating hole 12 that accommodates the upper part of the battery cell 3, and is assembled to the second frame 20 to form the battery case 2, with the battery cell 3 accommodated in the first accommodating hole 12, the through hole 39, and the second accommodating hole 23.

[0023] 4 is a partially cutaway perspective cross-sectional view of the second frame 20. The second frame 20 has a plate-shaped main body 21 and side walls 22 that rise around the periphery of the main body 21. A number of second housing holes 23 that house the lower portions of the battery cells 3 are formed to penetrate the main body 21 from top to bottom.

[0024] 5A and 5B are enlarged perspective cross-sectional views, partially cut away, of the second frame 20 with the heat insulating material 38 and battery cells 3 assembled thereto, viewed obliquely from below. A protrusion 26 that protrudes inward is formed at the lower end of the inner wall 25 of the second accommodating hole 23. The protrusion 26 protrudes with a substantially uniform width around the entire circumference of the inner wall 25, which has a substantially circular cross section (annular flange portion). In other words, the inner peripheral edge 27 of the protrusion 26 is substantially circular. The lower surface of the protrusion 26 is flush with the lower surface 24 of the main body 21.

[0025] The lower portions of the battery cells 3 are inserted from above into the second accommodating holes 23, and the lower end surfaces of the battery cells 3 abut against the protrusions 26, thereby supporting and positioning the battery cells 3 within the second accommodating holes 23. This aligns the height of the bottom surfaces of the battery cells 3 accommodated in the battery case 2, thereby preventing a decrease in the cooling quality of the battery cells when a cooling plate is joined to the underside of the battery case 2. Furthermore, because the vertical positions of the connection terminals 4 of the battery cells 3 are all aligned, joining the connection pieces 42 of the bus bars 40 to the connection terminals 4 is easier, and the quality of the connection is improved.

[0026] 6A and 6B are diagrams showing a first modified example of the second frame 20. A protrusion 28 that protrudes inward is formed at the lower end of the inner wall 25 of the second accommodating hole 23. The protrusion 28 is formed to protrude around the entire periphery of the inner wall 25, which has a substantially circular cross section (annular flange portion), but its width is not constant. In this example, the inner peripheral edge 29 of the protrusion 28 is substantially square. By using such a shape, it is possible to improve manufacturing efficiency and reduce the amount of material used, while maintaining the function of positioning the bottom of the battery cell 3.

[0027] 7A and 7B are diagrams showing a second modified example of the second frame 20. A protrusion 30 that protrudes inward is formed at the lower end of the inner wall 25 of the second accommodating hole 23. The protrusion 30 is formed to protrude around the entire periphery of the inner wall 25, which has a substantially circular cross section (annular flange portion), but its width is not constant. In this example, the inner peripheral edge 31 of the protrusion 30 is substantially hexagonal. By using such a shape, it is possible to improve manufacturing efficiency and reduce the amount of material used, while maintaining the function of positioning the bottom of the battery cell 3.

[0028] 8A and 8B are diagrams showing a third modified example of the second frame 20. Protrusions 32 that protrude inward are formed at the lower end of the inner wall 25 of the second accommodating hole 23. The protrusions 32 are formed at two opposing locations on the inner wall 25, which has a substantially circular cross section, and there are also portions 33 where no protrusions 32 are formed (multiple flange portions). By using this shape, it is possible to improve manufacturing efficiency and reduce the amount of material used, while maintaining the function of positioning the bottom of the battery cell 3.

[0029] 9A and 9B are diagrams showing a fourth modified example of the second frame 20. Claw-shaped protrusions 35 that protrude inward are formed at the lower end of the inner wall 25 of the second accommodating hole 23. In this example, three protrusions 35 are formed for each second accommodating hole 23 so as to be evenly spaced and close to the protrusions 35 of other adjacent second accommodating holes 23. Furthermore, in this example, unlike the fourth modified example, the lower surfaces of the protrusions 35 are flush with the lower surface 24 of the main body 21. By using such a shape, it is possible to improve manufacturing efficiency and reduce the amount of material used, while maintaining the function of positioning the bottoms of the battery cells 3.

[0030] In the above example, a protrusion is provided at the lower end of the second accommodating hole as the positioning portion, but the form of the positioning portion is not limited to the above example. In addition, the above examples can be modified or combined as appropriate. [Industrial Applicability]

[0031] It can be suitably used in a battery module. [Explanation of symbols]

[0032] 1 Battery Module 2 Battery case 3 battery cells 10 First Frame 20 2nd Frame 40 Busbar 50 Top cover

Claims

1. a first frame having a plurality of first accommodating holes formed therein that can accommodate one end of a battery cell having a connection terminal at the one end; a second frame having a plurality of second accommodating holes formed therein that can accommodate the other ends of the battery cells, the first accommodating holes and the second accommodating holes forming an accommodating chamber that can accommodate the battery cells; and the second accommodating hole has a positioning portion that positions the other end of the battery cell in the accommodating direction, The positioning portion is a protrusion formed around the entire circumference of a lower end portion of the second accommodating hole so as to protrude toward the inside of the second accommodating hole. Battery case.

2. The protruding portion is an annular flange portion having an inner peripheral edge that is substantially circular. The battery case according to claim 1 .

3. The protruding portion is an annular flange portion having an inner peripheral edge in a substantially rectangular shape. The battery case according to claim 1 .

4. The protruding portion is an annular flange portion having an inner peripheral edge in a substantially hexagonal shape. The battery case according to claim 1 .

5. a first frame having a plurality of first accommodating holes formed therein that can accommodate one end of a battery cell having a connection terminal at the one end; a second frame having a plurality of second accommodating holes formed therein that can accommodate the other ends of the battery cells, the first accommodating holes and the second accommodating holes forming an accommodating chamber that can accommodate the battery cells; and the second accommodating hole has a positioning portion that positions the other end of the battery cell in the accommodating direction, the positioning portion is a protrusion provided on at least a part of a lower end portion of the second accommodating hole and formed to protrude toward an inside of the second accommodating hole, The lower surface of the protrusion is flush with the lower surface of the second frame. Battery case.

6. The protrusions are a plurality of flanges formed to face each other. The battery case according to claim 5 .

7. The protrusion is a plurality of claws. The battery case according to claim 5 .

8. The battery case according to any one of claims 1 to 7, a plurality of battery cells, each having one end having a connection terminal housed in the first housing hole and the other end housed in the second housing hole and positioned by the positioning portion; a conductive member attached to an outer surface of the first frame and connected to the connection terminals of the plurality of battery cells; A battery module having:

9. the conductive member is a plate-shaped bus bar, The bus bar and the connection terminal are connected by laser welding. The battery module according to claim 8 .

Images