Battery case

Abstract

A battery case according to the present invention has: a first frame in which a plurality of first accommodating holes are formed, the first accommodating holes being 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, and an accommodating chamber capable of accommodating the battery cells is formed by the first accommodating holes and the second accommodating holes, the second accommodating holes being capable of accommodating the other ends of the battery cells, the second accommodating hole has a positioning portion for positioning the other end portion of the battery cell in the accommodating direction, and the positioning portion is a protruding portion formed so as to protrude toward the inside of the second accommodating hole over the entire circumference of the lower end portion of the second accommodating hole.

Description

Technical Field

[0001] The present disclosure relates to battery casings. Background Art

[0002] A battery module is constructed by housing multiple battery cells in a battery case and connecting conductive components to the cell terminals. Patent Document 1 discloses a cooling structure in which a heat-conducting material is placed between the battery cells and a cooling plate, allowing them to contact and release heat.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2023-524698. Summary of the Invention

[0006] Problems to be solved by the invention

[0007] When a battery case houses multiple battery cells, the cells may be positioned at different heights. This can lead to differences in thermal conductivity between the bottom surfaces of the battery cells and the cooling plate, resulting in reduced cooling quality for some battery cells compared to others.

[0008] An object of the present disclosure is to provide a battery case that can suppress variations in the height positions of battery cells and suppress a decrease in the cooling quality of the bottom surfaces of the battery cells.

[0009] Solutions to the Problem

[0010] The battery case disclosed herein comprises: a first frame, which is formed with a plurality of first accommodating holes, and the first accommodating holes can accommodate one end of a battery cell having a connecting terminal at one end; and a second frame, which is formed with a plurality of second accommodating holes, and the first accommodating holes and the second accommodating holes form an accommodating chamber that can accommodate the battery cell, and the second accommodating hole can accommodate the other end of the battery cell, and the second accommodating hole has a positioning portion for positioning the other end of the battery cell in the accommodating direction, and the positioning portion is a protrusion formed in a manner of protruding toward the inner side of the second accommodating hole along the entire circumference of the lower end of the second accommodating hole.

[0011] Effects of the Invention

[0012] According to the present disclosure, by positioning the lower end of the battery cell in the second receiving hole of the second frame, the height of the battery cell bottom surface relative to the battery case is aligned, thereby suppressing a reduction in cooling quality of the battery cell bottom surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a diagram showing the appearance of a battery module.

[0014] Figure 2 This is an exploded view of the battery module.

[0015] Figure 3 This is a further exploded view of the battery module.

[0016] Figure 4 It is a partially cutaway perspective sectional view of the second frame.

[0017] Figure 5A This is an enlarged view of the second frame.

[0018] Figure 5B This is an enlarged view of the second frame.

[0019] Figure 6A It is an enlarged view of the first modified example of the second frame.

[0020] Figure 6B It is an enlarged view of the first modified example of the second frame.

[0021] Figure 7A It is an enlarged view of a second modification of the second frame.

[0022] Figure 7B It is an enlarged view of a second modification of the second frame.

[0023] Figure 8A It is an enlarged view of the third modified example of the second frame.

[0024] Figure 8B It is an enlarged view of the third modified example of the second frame.

[0025] Figure 9A It is an enlarged view of a fourth modification of the second frame.

[0026] Figure 9B It is an enlarged view of a fourth modification of the second frame.

[0027] Figure 10 This is an exploded view of a conventional battery module.

[0028] Figure 11A This is a diagram showing the appearance of a conventional battery module.

[0029] Figure 11B yes Figure 11A Magnified view of part A.

[0030] Description of Reference Numerals

[0031] 1 battery module

[0032] 2 Battery housing

[0033] 3 battery cells

[0034] 10 First Frame

[0035] 20 Second Frame

[0036] 40 busbars

[0037] 50 Top cover DETAILED DESCRIPTION

[0038] The following describes an embodiment of the present disclosure with reference to the accompanying drawings. Each embodiment described below represents a specific example of the present disclosure. Therefore, the various components, their configurations, and connection methods shown in the following embodiments are examples, and are not intended to limit the present disclosure. Furthermore, components of the following embodiments that are not described in the technical solution are described as arbitrary components.

[0039] In addition, each figure is a schematic diagram and does not necessarily illustrate accurately. It should be noted that in each figure, the same reference numerals are given to substantially the same structure, and repeated descriptions are omitted or simplified.

[0040] First, a comparative example battery module 100 will be described. There is a battery module in which a plurality of battery cells are housed in a battery case and conductive members are connected to connection terminals of the battery cells. Figure 10 FIG1 is an exploded view showing the main parts of a conventional battery module 100. Figure 11A shows the appearance of the battery module 100, Figure 11B yes Figure 11A An enlarged view of section A. Some parts are omitted from the illustration.

[0041] The battery cells 103 are housed in a battery housing 102 having a first frame 110 and a second frame 120. A plurality of first and second receiving holes 111 and 121 are formed in the first and second frames 110 and 120 in an opposing manner, respectively, forming a housing for the battery cells 103.

[0042] The upper portion 105 of the battery cell 103 is received in the first receiving hole 111 , and the lower portion of the battery cell 103 is received in the second receiving hole 121 , so that the battery cells 103 are respectively fixed and received in the battery case 102 .

[0043] The bus bar 140, a conductive component, is provided on the upper surface of the first frame 110. A connecting piece 142, formed to protrude laterally from a main body 141, overlaps with the connecting terminal 104 of the battery cell 103 and is joined together by laser welding or the like. In the illustrated example, the bus bar 140 and the connecting terminal 104 are joined by the connecting piece 142. However, in some cases, the main body 141 of the bus bar 140 and the connecting terminal 104 are connected by wire bonding.

[0044] When assembling the battery module 100, the second frame 120 is placed on the loading platform with the second receiving hole 121 facing upward, the battery cell 103 is received in the second receiving hole 121 with its connection terminal 104 facing upward, and the first frame 110 is placed on the second frame 120 with its first receiving hole 111 facing downward and the upper part 105 of the battery cell 103 is received in the first receiving hole 111 for combination.

[0045] Next, busbar 140 is mounted on first frame 110, and connecting tabs 142 are bonded to connection terminals 104. Furthermore, a potting agent (not shown) is applied to cover busbar 140, and then a top cover (not shown) is placed over it. Furthermore, a cooling plate 152 is bonded to the bottom of second frame 120 using adhesive 151.

[0046] The busbar 140 is formed by press-molding a plate-shaped member, so the heights of the multiple connecting pieces 142 are approximately the same. When the connecting pieces 142 are joined to the connecting terminals 104, if the heights of the connecting terminals 104 of the multiple battery cells 103 are not aligned, gaps may form between some of the connecting pieces 142 and the connecting terminals 104.

[0047] exist Figure 11B In the figure, the height of the battery cell 103 on the right side is appropriate and is inserted into the deepest part of the first receiving hole 111 (inserted into the uppermost part in the figure). Therefore, the connecting piece 142 is properly in contact with the connecting terminal 104. In contrast, the battery cell 103' on the left side is at a lower position than the battery cell 103 on the right side and is therefore not inserted into the deepest part of the first receiving hole 111'. Therefore, a gap G is generated between the connecting piece 142' and the connecting terminal 104'.

[0048] In order to join the connecting piece 142' to the connecting terminal 104', there are the following problems: the complexity of the process, such as lifting the battery cell 103' while joining or pressing the connecting piece 142' while joining, leads to a decrease in the efficiency of the joining operation. Moreover, even if joining is possible, internal stress will remain in the connecting piece 142', thereby reducing the joining quality.

[0049] Figure 11 shows the appearance of the battery module 1 of the present disclosure, Figure 2 This is an exploded view of the battery module 1. The battery module 1 accommodates a plurality of battery cells 3 in a resin battery case 2. The battery case 2 has a first frame 10 and a second frame 20, and the first frame 10 and the second frame 20 form a storage chamber for the battery cells 3 inside. A bus bar 40 is installed on the upper surface of the first frame 10, and the bus bar 40 is connected to the connection terminal of the battery cell 3. The bus bar 40 is covered with a potting agent not shown in the figure, and a top cover 50 is provided thereon, and the top cover 50 covers the upper surface of the first frame 10 and the bus bar 40. In addition, a cooling plate 52 is bonded to the lower surface of the second frame 20 by an adhesive 51. The lower surface of the battery cell 3 is exposed from the lower part of the second frame 20 and is connected to the cooling plate 52 by an adhesive 51.

[0050] Figure 3 This is an exploded view of the battery case 2, further disassembled from the battery module 1. The second frame 20 is a container-like component with an open top, formed with multiple second accommodating holes 23 for accommodating the lower portions of the battery cells 3. The second frame 20 houses a thermal insulation material 38, which has multiple through-holes 39 formed therein for inserting the battery cells 3. The battery cells 3 are accommodated at their lower portions in the second accommodating holes 23, with their intermediate portions inserted into the through-holes 39, surrounded by the thermal insulation material 38.

[0051] The first frame 10 is formed with a first receiving hole 12 for receiving the upper portion of the battery cell 3 . The first frame 10 is assembled to the second frame 20 to form the battery case 2 . The battery cell 3 is received in the first receiving hole 12 , the through hole 39 , and the second receiving hole 23 .

[0052] Figure 4 This is a partially cutaway perspective cross-sectional view of the second frame 20. The second frame 20 includes a plate-shaped main body 21 and sidewalls 22 extending around the main body 21. Multiple second receiving holes 23 are formed vertically through the main body 21 to accommodate the lower portions of the battery cells 3.

[0053] Figure 5A and Figure 5B This is an enlarged view of a partially cutaway perspective sectional view showing the state in which the heat insulating material 38 and the battery cell 3 are assembled on the second frame 20, as viewed from an oblique angle below. A protrusion 26 is formed at the lower end of the inner wall 25 of the second receiving hole 23, protruding inward. The protrusion 26 (annular flange) is formed to protrude with approximately the same width around the entire circumference of the inner wall 25, which has a generally circular cross-section. In other words, the inner peripheral edge 27 of the protrusion 26 is generally circular in shape. Furthermore, the lower surface of the protrusion 26 is flush with the lower surface 24 of the main body 21.

[0054] The lower portion of the battery cell 3 is inserted from above into the second receiving hole 23, with the lower end surface of the battery cell 3 abutting against the protrusion 26, thereby supporting and positioning the battery cell 3 within the second receiving hole 23. This aligns the bottom surfaces of the battery cells 3 housed in the battery case 2, thus minimizing degradation in the cooling quality of the battery cells when the cooling plate is attached to the lower surface of the battery case 2. Furthermore, the vertical alignment of the connection terminals 4 of the battery cells 3 facilitates the connection between the connecting tabs 42 of the busbar 40 and the connection terminals 4, improving the quality of the connection.

[0055] Figure 6A and Figure 6B This figure shows 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 receiving hole 23. The protrusion 28 (annular flange) is formed protruding from the entire circumference of the inner wall 25, which is roughly circular in cross section, but its width is not constant. In this example, the inner peripheral edge 29 of the protrusion 28 is roughly quadrilateral. By setting it to such a shape, it is possible to achieve improved manufacturing efficiency and reduction in material usage while still serving the function of positioning the bottom of the battery cell 3.

[0056] Figure 7A and Figure 7B This figure shows 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 (annular flange portion) is formed protruding from the entire circumference of the inner wall 25, which is roughly circular in cross section, but its width is not constant. In this example, the inner peripheral edge 31 of the protrusion 30 is roughly hexagonal. By setting it to such a shape, it is possible to achieve improved manufacturing efficiency and reduction in material usage while still serving the function of positioning the bottom of the battery cell 3.

[0057] Figure 8A and Figure 8B This figure shows a third modified example of the second frame 20. A protrusion 32 is formed at the lower end of the inner wall 25 of the second receiving hole 23, protruding inward. The protrusions 32 are formed at two opposing locations on the inner wall 25, which has a generally circular cross-section. There are also portions 33 (plural flanges) where the protrusions 32 are not formed. This shape improves manufacturing efficiency and reduces material usage while still functioning as a base for positioning the battery cells 3.

[0058] Figure 9A and Figure 9BThis figure shows a fourth modified example of the second frame 20. A claw-shaped protrusion 35 that protrudes inward is formed at the lower end of the inner wall 25 of the second receiving hole 23. In this example, three protrusions 35 are formed at equal intervals in one second receiving hole 23, and the protrusions 35 are formed in a manner close to the protrusions 35 of other adjacent second receiving holes 23. In this example, the lower surface of the protrusion 35 is flush with the lower surface 24 of the main body 21. By setting it to such a shape, while still serving the function of positioning the bottom of the battery cell 3, it is possible to achieve improved manufacturing efficiency and reduction in material use.

[0059] In the above example, a protrusion is provided at the lower end of the second receiving hole as a positioning portion, but the form of the positioning portion is not limited to the above example. In addition, the above examples can also be appropriately modified or combined.

[0060] Industrial Applicability

[0061] The present invention can be suitably used in a battery module.

Claims

1. A battery housing, characterized in that: have: a first frame formed with a plurality of first receiving holes capable of receiving one end of a battery cell having a connection terminal at one end; as well as a second frame having a plurality of second receiving holes formed therein, wherein the first receiving holes and the second receiving holes form a receiving chamber capable of receiving the battery cell, wherein the second receiving hole is capable of receiving the other end of the battery cell; The second receiving hole has a positioning portion for positioning the other end portion of the battery cell in the receiving direction. The positioning portion is a protrusion formed along the entire circumference of the lower end portion of the second accommodation hole so as to protrude toward the inside of the second accommodation hole.

2. The battery case according to claim 1, wherein The protrusion is an annular flange portion whose inner peripheral edge is substantially circular.

3. The battery case according to claim 1, wherein The protrusion is an annular flange portion having a substantially quadrilateral inner peripheral edge.

4. The battery case according to claim 1, wherein The protrusion is an annular flange portion having a substantially hexagonal inner peripheral edge.

5. A battery housing, characterized in that: have: a first frame formed with a plurality of first receiving holes capable of receiving one end of a battery cell having a connection terminal at one end; as well as a second frame having a plurality of second receiving holes formed therein, wherein the first receiving holes and the second receiving holes form a receiving chamber capable of receiving the battery cell, wherein the second receiving hole is capable of receiving the other end of the battery cell; The second receiving hole has a positioning portion for positioning the other end portion of the battery cell in the receiving direction. The positioning portion is a protrusion provided at at least a portion of the lower end portion of the second receiving hole and formed so as to protrude toward the inside of the second receiving hole. A lower surface of the protrusion is on the same plane as a lower surface of the second frame.

6. The battery case according to claim 5, wherein: The protrusions are a plurality of flange portions formed in an opposing manner.

7. The battery case according to claim 5, wherein: The protrusions are a plurality of claws.

8. A battery module, characterized in that: have: The battery housing according to claim 1; a plurality of battery cells, wherein one end portion of the battery cell having a connection terminal is received in the first receiving hole, and the other end portion of the battery cell is received in the second receiving hole and positioned relative to the second receiving hole by the positioning portion; as well as A conductive component is mounted on an outer surface of the first frame and connected to the connection terminals of the plurality of battery cells.

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

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