Battery case

Abstract

To provide a battery case that enables efficient connection of the connection terminals of a battery cell and a conductive member without deteriorating the 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 first accommodating holes have a fixing portion that positions and fixes one end of the battery cell.SELECTED DRAWING: Figure 4A

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 describes a battery module in which multiple cylindrical battery cells are arranged side by side. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2021-501457 Summary of the Invention [Problem to be solved by the invention]

[0004] When multiple battery cells are arranged side by side, the heights of the cells can vary, which can lead to issues such as unstable connection quality when connecting the cells to the electrodes.

[0005] The present disclosure aims to provide a battery case that allows for easy positioning of battery cells in the vertical direction, thereby enabling efficient joining of connection terminals and conductive members without compromising joining quality. [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, the first accommodating holes and the second accommodating holes forming an accommodating chamber that can accommodate the battery cell, and the first accommodating holes have a fixing portion that positions and fixes one end of the battery cell. [Effects of the Invention]

[0007] In the present disclosure, by positioning and fixing the end portion of the battery cell having the connection terminal in the first housing hole of the first frame, the height of the connection terminal of the battery cell is aligned relative to the first frame, which makes the work of connecting the conductive member to the connection terminal more efficient and improves the quality of the connection. [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 4A] FIG. 2 is a cross-sectional view of the battery module. [Figure 4B] FIG. 2 is an enlarged cross-sectional view of the battery module. [Figure 5] 1A to 1C are diagrams illustrating an assembly process of a battery module. [Figure 6] 1A to 1C are diagrams illustrating an assembly process of a battery module. [Figure 7] FIG. 10 is an exploded view showing a conventional battery module. [Figure 8A] FIG. 1 is a diagram showing the appearance of a conventional battery module. [Figure 8B] 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. 7 shows an exploded view of the main parts of a conventional battery module 100. Fig. 8A shows the external appearance of the battery module 100, and Fig. 8B 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 8B, the right-side 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-side battery cell 103' is at a lower position than the right-side 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] The battery module 1 according to the present disclosure makes it possible to easily position the battery cells in the vertical direction, thereby enabling efficient joining of the connection terminals and conductive members, and providing a battery case in which the joining quality is not reduced.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] Fig. 4A is a cross-sectional view of a battery module 1 accommodating battery cells 3 according to the present disclosure, and Fig. 4B is an enlarged view of a main portion thereof. The battery module 1 has a first frame 10 in which a large number of first accommodating holes 12 are formed, and a second frame 20 in which second accommodating holes 23 are formed that correspond to the first accommodating holes 12 and form an accommodating chamber together with the first accommodating holes 12. The first accommodating holes 12 in the first frame 10 and the second accommodating holes 23 in the second frame 20 form an accommodating chamber in which a battery cell 3 is accommodated.

[0025] The first frame 10 is a plate-shaped member, and has a main body 11 formed with a large number of first accommodating holes 12. The first frame 10 functions as a lid-like member for the container-shaped second frame 20. The inner surface of the first accommodating holes 12 is formed with engaging protrusions 13 that protrude inward. The upper side surfaces of the battery cells 3 are formed with engaging recesses 5, and the engaging protrusions 13 engage with the engaging recesses 5, positioning and fixing the battery cells 3 relative to the first frame 10.

[0026] A large number of second accommodating holes 23 are formed in the main body 21 of the second frame 20 at positions corresponding to the first accommodating holes 12. The lower portions 8 of the battery cells 3 are supported by the underside of the second frame 20.

[0027] The peripheral portions of the first frame 10 and the second frame 20 are peripheral wall portions 14, 22, respectively, which are joined together and integrally to form a case-like structure having an internal space.

[0028] A heat insulating material 38 is housed between the first frame 10 and the second frame 20 so as to cover the battery cells 3. The heat insulating material 38 is made of hard urethane and is a thick plate-like member with many through holes 39 formed therein into which the battery cells 3 are inserted. Note that the material of the heat insulating material 38 is not limited to hard urethane.

[0029] The upper part 6 of the battery cell 3 is fixedly accommodated in the first accommodation hole 12 of the first frame 10, the middle part 7 is inserted into the through hole 39 of the insulating material 38, and the lower part 8 is accommodated in the second accommodation hole 23 of the second frame 20.

[0030] 4B, a bus bar 40 serving as a conductive member is attached to the top surface of the first frame 10. The bus bar 40 has a thin plate-shaped main body 41 and plate-shaped connection pieces 42 extending laterally from the main body 41. The main body 41 is attached to the top surface of the first frame 10, and the connection pieces 42 extend to the top surfaces of the connection terminals 4 of the battery cells 3.

[0031] 5 is a diagram showing the procedure for assembling the first assembly 70 during the assembly of the battery module. First, the first frame 10 is placed on a mounting surface in the assembly workshop with its first accommodating hole 12 facing upward. In other words, the first frame 10 is placed on the mounting surface upside down from the position in which it is normally used as the battery module 1.

[0032] Next, the heat insulating material 38 is turned upside down and placed on the first frame 10 with the through-hole 39 positioned above the first receiving hole 12 .

[0033] Next, the battery cell 3 is placed in the first accommodating hole 12 with the upper portion 6 where the connection terminals 4 are located facing downwards by inserting it into the through-hole 39 of the heat insulating material 38. At this time, the engaging protrusions 13 provided in the first accommodating hole 12 engage with the engaging recesses 5 provided in the battery cell 3, fixing the battery cell 3 to the first frame 10.

[0034] Once all the battery cells 3 have been accommodated and fixed in the first accommodating holes 12, the second frame 20 is placed on top of the first frame 10 with its second accommodating holes 23 facing downwards, and the lower parts 8 (upper parts in the figure) of the battery cells 3 are accommodated in the second accommodating holes 23, and the first frame 10 and the second frame 20 are fixed together to form a first assembly 70.

[0035] Next, the first assembly 70 is inverted so that the first frame 10 is on top and the second frame 20 is on the bottom. At this time, a plate-shaped jig 60 is placed on the second frame 20 to prevent the battery cells 3 from falling out of the second housing holes 23 of the second frame 20. Note that if the second frame 20 is provided with positioning parts that prevent the battery cells 3 from falling out, the use of the jig 60 can be omitted.

[0036] FIG. 6 is a diagram showing the procedure for assembling a battery module 1 from the inverted first assembly 70. The busbar 40 is placed on the upper surface of the first assembly 70, i.e., the upper surface of the first frame 10, so that its connection piece 42 is positioned over the predetermined connection terminal 4 of the battery cell 3, and the connection piece 42 and the connection terminal 4 are fixed by welding. Various known welding methods can be used. In the present disclosure, the connection piece 42 and the connection terminal 4 are fixed by laser welding. The welding method may also be ultrasonic welding, etc.

[0037] Then, a potting agent (not shown) is applied to the first frame 10 so as to seal the bus bars 40. Then, the top cover 50 is placed on top of that. Finally, adhesive 51 is applied to the cooling plate 52 used to cool the battery cells 3, and the first assembly 70 is placed on top of that for integration.

[0038] In this way, the first frame 10 is inserted into the first accommodating holes 12 with the upper part 6 containing the connection terminals 4 of the battery cells 3 facing downwards, and then accommodated and fixed therein, so that the height positions of the connection terminals 4 are aligned with respect to the first frame 10. This ensures that the connection pieces 42 of the busbars 40 and the connection terminals 4 of the battery cells 3 are in appropriate contact, allowing the connection pieces 42 and the connection terminals 4 to be efficiently connected by welding.

[0039] In the above example, the battery cells 3 are positioned and fixed to the first frame 10 by engaging the engagement recesses 5 formed in the upper parts 6 of the battery cells 3 with the engagement protrusions 13 formed in the first accommodating holes 12, but the upper parts 6 of the battery cells 3 may also be fixed to the first accommodating holes 12 by an interference fit. Furthermore, instead of an interference fit, the upper parts 6 and the first accommodating holes 12 may also be fixed by adhesive. In other words, the means for fixing the upper parts 6 to the first accommodating holes 12 is not limited in any way as long as it can properly position the upper parts 6 relative to the first accommodating holes 12. [Industrial Applicability]

[0040] It can be suitably used in a battery module. [Explanation of symbols]

[0041] 1 Battery Module 2 Battery case 3 battery cells 10 First Frame 20 2nd Frame 40 Bus bar (conductive member) 50 Top cover 60 Jig 70 1st assembly

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 first accommodating hole has a fixing portion that positions and fixes one end of the battery cell; Battery case.

2. the fixing portion is an engaging protrusion that engages with an engaging recess formed on the battery cell; The battery case according to claim 1 .

3. the fixing portion is a reduced diameter portion that fits the battery cell; The battery case according to claim 1 .

4. The fixing portion is an adhesive portion that adheres the battery cell. The battery case according to claim 1 .

5. the second accommodating hole has a positioning portion that positions the other end of the battery cell in the accommodating direction; The battery case according to any one of claims 1 to 4.

6. The battery case according to claim 1; a plurality of battery cells, each having a connection terminal housed in the first housing hole and positioned and fixed by the fixing portion, and each having the other end housed in the second housing hole; 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:

7. 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 6 .

8. 8. A method for assembling a battery module according to claim 6 or 7, comprising: placing the first frame on a placement surface with the first accommodating hole facing up; The battery cell is accommodated in the first accommodation hole with the connection terminal facing downward, and the battery cell is positioned and fixed in the first accommodation hole by the fixing portion; the second frame is placed on the first frame with the second accommodating hole facing downward to form a first assembly in which the battery cell is accommodated in the accommodating chamber; The first assembly is turned upside down. a conductive member attached to an upper surface of the first frame and connecting the conductive member to the connection terminal; How to assemble a battery module.

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

Images