Battery pack

Abstract

The present application relates to a battery pack, comprising: a box body, which is provided with a cavity for accommodating a plurality of battery cells, and a pressure relief chamber corresponding to an explosion-proofing valve of the battery cells; the plurality of battery cells; and at least one cooling assembly, said cooling assembly being arranged on one side of the battery cells in the direction of arrangement of the plurality of battery cells. The cooling assembly comprises a cooling body and at least one protrusion connected to the cooling body, the cooling body abutting against a plurality of battery cells in a corresponding row, and the protrusion being inserted into the pressure relief chamber.

Description

battery pack

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on July 20, 2023, with application number 202310898476.0. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a battery pack. Background Art

[0003] With the rapid development of new energy vehicles, pure electric vehicle users are increasingly demanding higher range and charging rates. As a result, battery cells are becoming increasingly energy-intensive, leading to higher heat generation during operation. Furthermore, as the number of cells and charging rates increase, temperature consistency becomes increasingly difficult to control, necessitating the use of more efficient liquid cooling solutions to maintain cooling and temperature uniformity across the cells.

[0004] In related technologies, to address the problem of high heat generation in cylindrical battery packs, a serpentine tube side liquid cooling solution is usually adopted, that is, a serpentine tube is in contact with the side of the battery cell, and the coolant flows in the serpentine tube cavity to form convection heat exchange with the battery cell.

[0005] Furthermore, cylindrical cells offer the advantage of releasing pressure downward during thermal runaway. To ensure passenger safety, the heat diffusion after thermal runaway must be channeled. Therefore, the design of the pressure relief path and the structural strength of the battery pack are crucial to vehicle safety. SUMMARY OF THE INVENTION

[0006] The present application provides a battery pack to solve the above technical problems.

[0007] An embodiment of the present application provides a battery pack, comprising: a box body, provided with a cavity for accommodating multiple battery cells and a pressure relief cavity corresponding to the explosion-proof valve of the battery cells; multiple battery cells; at least one cooling assembly, wherein the cooling assembly is arranged on the side of the battery cells along the arrangement direction of the multiple battery cells; wherein the cooling assembly includes a cooling body and at least one protrusion connected to the cooling body, the cooling body abuts against the multiple battery cells in the corresponding row, and the protrusion is inserted into the pressure relief cavity. Beneficial effects

[0008] The beneficial effects of the present application are as follows: by arranging the cooling assembly on the side of the battery cells along the arrangement direction of the multiple battery cells, and arranging a cooling body and at least one protrusion connected to the cooling body in the cooling assembly, so that the cooling body abuts against the multiple battery cells, and the protrusion is inserted into the pressure relief cavity, the present application can utilize the protrusion to support the battery cells and the cooling body, enhance the structural strength of the battery pack, improve the uniformity of the battery cell temperature, and at the same time guide the heat diffusion after thermal runaway of the battery cells to improve safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG1 shows an exploded schematic diagram of a battery pack according to an embodiment of the present application.

[0010] FIG2 shows a side view of a cooling assembly according to an embodiment of the present application.

[0011] FIG3 is a schematic diagram showing the three-dimensional structure of the cooling assembly according to an embodiment of the present application.

[0012] FIG4 shows a schematic structural diagram of a cooling pipe according to an embodiment of the present application.

[0013] FIG5 is a bottom schematic diagram of a cooling assembly according to an embodiment of the present application.

[0014] FIG6 is a schematic diagram showing a pressure relief chamber according to an embodiment of the present application.

[0015] FIG7 is a schematic diagram showing the battery pack after installation according to an embodiment of the present application. Modes for Carrying Out the Invention

[0016] Figure 1 shows an exploded schematic diagram of a battery pack according to an embodiment of the present application. As shown in Figure 1 , the battery pack may include a housing 1, multiple battery cells 2, and at least one cooling assembly 3. The housing 1 may be a rectangular parallelepiped structure with an upward opening, and may include a cavity therein for accommodating the multiple battery cells 2.

[0017] Referring to Figure 1, the plurality of battery cells 2 can be arranged in rows, and the battery cells 2 in two adjacent rows are staggered. For example, in Figure 1, the plurality of battery cells 2 can be arranged along the row direction (i.e., the x-direction), and the battery cells 2 in alternate rows can be arranged along the y-direction perpendicular to the row direction. Specifically, the plurality of battery cells 2 have odd rows and even rows, and the arrangement of the battery cells 2 in the plurality of odd rows is consistent, and the arrangement of the battery cells 2 in the plurality of even rows is consistent, so that different battery cells 2 in odd rows can be arranged on the same straight line along the y-direction, and different battery cells 2 in even rows can also be arranged on the same straight line along the y-direction. In this way, the arrangement of the plurality of battery cells 2 can be more compact, thereby improving the energy density of the battery pack and saving space.

[0018] In one embodiment, the cooling assembly 3 is disposed on the side of the battery cells 2 in the corresponding row along the row direction of the battery cells 2. The cooling assemblies 3 may be arranged sequentially along the y-direction. Alternatively, the cooling assembly 3 may be installed in the gap between two adjacent rows of battery cells 2 along the height direction of the battery cells 2.

[0019] The cooling assembly 3 may be provided with one or more cooling assemblies. When multiple cooling assemblies 3 are provided, two adjacent cooling assemblies 3 may be located on either side of the same row of battery cells 2. Two adjacent cooling assemblies 3 may also be located on either side of two adjacent rows of battery cells 2. This allows the two cooling assemblies 3 to be aligned along the row direction of the battery cells 2, rather than being staggered. This improves the battery pack structure while saving the number of cooling assemblies, reducing costs and also reducing the overall weight of the battery pack.

[0020] In one embodiment, as shown in FIG1 , the cooling assembly 3 may include a cooling body 31 and at least one protrusion 32 connected to the cooling body 31. The cooling body 31 and the at least one protrusion 32 are both arranged along the height direction of the battery cells 2. The cooling body 31 abuts against the multiple battery cells 2 in the corresponding row. The cooling body 31 may partially contact the multiple battery cells 2 in the corresponding row, and other portions of the cooling body 31 may form a gap between the multiple battery cells 2. The multiple protrusions 32 are arranged at intervals along the row direction of the multiple battery cells 2. The space between two protrusions 32 can be referred to as a hollow area.

[0021] By partially hollowing out the bottom of the serpentine tube cold plate to form at least one convex body, the embodiment of the present application can utilize the convex body to support the battery cell and the cooling body, thereby enhancing the structural strength of the battery pack.

[0022] In one embodiment, the cooling body 31 and the convex body 32 can both be hollow structures. The cooling body 31 and the convex body 32 are connected, and the cooling body 31 and the convex body 32 form a U-shaped structure, which can further play a role in equalizing the temperature of the battery cells and solve the high temperature problem caused by fast charging of large cylindrical batteries.

[0023] FIG2 shows a side view of a cooling assembly according to an embodiment of the present application. Referring to FIG2 , the cooling body 31 may include a first sub-body 311 and a second sub-body 312 and a third sub-body 313 disposed at both ends of the first sub-body 311 .

[0024] In one embodiment, the first sub-body 311 extends along the row direction of the plurality of battery cells 2. The first sub-body 311 may have a serpentine (or wavy) structure.

[0025] In one embodiment, the first sub-body 311 includes a plurality of first curved surfaces 3111, which are aligned with the sides of corresponding rows of the battery cells 2. For example, in FIG2 , the first curved surfaces 3111 and the first curved surface 3112 are adjacent to each other, and the protrusion 32 can be connected to the first curved surfaces 3111 and the first curved surfaces 3112. In other words, the protrusion 32 can be connected to two adjacent first curved surfaces 3111.

[0026] 2 , the second sub-body 312 and the third sub-body 313 are both connected to the first sub-body 311. Optionally, the second sub-body 312 and the first sub-body 311 are integrally formed, and the third sub-body 313 and the first sub-body 311 are integrally formed.

[0027] Figure 3 shows a schematic diagram of the three-dimensional structure of the cooling assembly according to an embodiment of the present application. It is worth noting that, to better illustrate the specific structure of the cooling assembly, one row of cells from Figure 1 is hidden in Figure 3. In reality, this row of cells could be located between two cooling assemblies. Referring to Figure 3, from a top-down perspective, the first sub-body 311 of the cooling assembly 3 has a serpentine structure and extends along the row direction of the multiple cells 2.

[0028] In one embodiment, the protrusion 32 may include a first protrusion 321 and a second protrusion 322 connected to the first protrusion 321. The first protrusion 321 is located directly below and connected to the first curved surface 3111; the second protrusion 322 is located directly below and connected to the first curved surface 3112. In other words, the first protrusion 321 and the second protrusion 322 may be connected to two adjacent first curved surfaces, respectively.

[0029] In one embodiment, the bending direction of the first curved surface connected to the first protrusion 321 is opposite to the bending direction of the first curved surface connected to the second protrusion 322. For example, the first curved surface 3111 can be bent along the y direction in Figure 1, and the first curved surface 3112 can be bent in the opposite direction of the y direction in Figure 1. In some embodiments, the first curved surface 3112 can be bent along the y direction in Figure 1, and the first curved surface 3111 can be bent in the opposite direction of the y direction in Figure 1. By connecting the protrusion with the two curved surfaces in opposite bending directions, the supporting effect of the protrusion on the first sub-body can be balanced, thereby making the structure of the cooling component more stable.

[0030] In one embodiment, the first convex portion 321 and the second convex portion 322 are both provided with a second curved surface 3221. Furthermore, the first convex portion 321 and the second convex portion 322 are both second curved surfaces 3221, and the bending direction of the second curved surface is the same as the bending direction of the first curved surface to which the second curved surface is connected. In this way, the first convex portion 321 and the second convex portion 322 are aligned with the corresponding first sub-body 311, thereby providing better support and facilitating the integral molding of the convex body and the first sub-body.

[0031] It should be noted that the first convex portion 321 and the second convex portion 322 may also have other shapes, such as a triangle. The first convex portion 321 is integrally formed with the first curved surface 3111, and the second convex portion 322 is integrally formed with the first curved surface 3112. In actual applications, the first convex portion 321 and the second convex portion 322 may be appropriately modified as needed, and this application is not limited thereto.

[0032] FIG4 is a schematic structural diagram of the cooling pipe of an embodiment of the present application. In conjunction with FIG2 and FIG4 , the second sub-body 312 has at least one connection hole 3121 for passing a cooling pipe, and the cooling pipe can be a liquid inlet pipe 33 or a liquid outlet pipe 34. Specifically, the second sub-body 312 can be provided with two connection holes, namely an inlet 3121 and an outlet 3122, and both the inlet 3121 and the outlet 3122 can be connection holes that pass through the second sub-body 312. The inlet 3121 can be used for the liquid inlet pipe 33 to extend into, so that the liquid inlet pipe 33 is set on the second sub-body 312; the outlet 3122 can be used for the liquid outlet pipe 34 to extend into, so that the liquid outlet pipe 34 is set on the second sub-body 312. The inlet 3121 and the outlet 3122 can be arranged along the height direction of the battery cell 2 to save the overall space in the row direction of the battery cell.

[0033] In one embodiment, coolant can flow into the liquid inlet pipe 33 and then be diverted to the corresponding cooling assembly. The cooling assembly removes heat from the multiple battery cells before flowing out of the liquid outlet pipe 34, forming a heat exchange cycle. It is worth noting that the arrangement of the liquid inlet pipe 33 and the liquid outlet pipe 34 is relative, not absolute. In actual operation, the relative position of the liquid inlet pipe 33 and the liquid outlet pipe 34 can be determined as needed.

[0034] Figure 5 shows a schematic diagram of the bottom of a cooling assembly according to an embodiment of the present application. As shown in Figure 5 , looking upward from the bottom of the cooling assembly, the first protrusion 321 and the second protrusion 322 can be attached to the sides of different rows of battery cells. For example, in Figure 5 , the top row of battery cells is row 1. For example, the second protrusion 322 is attached to the battery cells in row 1, and the first protrusion 321 is attached to the battery cells in row 2. The battery cells attached by the first protrusion 321 and the battery cells attached by the second protrusion 322 are adjacent to each other.

[0035] In one embodiment, a foam sealant 4 is potted between the cooling body 31 and the plurality of battery cells 2. In practical applications, the foam sealant 4 can also be potted between the plurality of battery cells and the sidewalls of the housing 1. As can be seen from Figures 1 and 5 , the overall appearance of the potted foam sealant 4 can be adapted to the sidewall structure of the housing 1, for example, forming a rectangular parallelepiped.

[0036] The foam glue 4 has foaming and bonding properties and can be used to bond the cooling body 31 and the plurality of battery cells 2. Due to the bonding of the foam glue 4, the cooling body 31 and the plurality of battery cells 2 can be considered as a whole, and the at least one protrusion 32 can support the whole.

[0037] By encapsulating foam glue between the cooling body and multiple battery cells, and at the same time bonding the multiple battery cells to the box body through the foam glue, the embodiment of the present application can enhance the overall structural strength of the battery pack, further balance the temperature of the battery cells, improve the temperature consistency of each battery cell, and also play a better insulation role under low temperature conditions.

[0038] FIG6 is a schematic diagram of the pressure relief chamber according to an embodiment of the present application. Referring to FIG6 , the top of the protrusion 32 is connected to the cooling body 31 , and the bottom of the protrusion 32 is in contact with the bottom of the box body 1 to form a pressure relief chamber 5 .

[0039] 1 and 6 , a pressure relief valve 50 is provided on the side wall of the housing 1. The housing 1 also has a pressure relief chamber 5 corresponding to the explosion-proof valve 60 of the battery cell 2. The protrusion 32 abuts the housing 1 and is inserted into the pressure relief chamber 5. The bottoms of the multiple battery cells 2, at least one protrusion 32, and the bottom of the housing 1 collectively form the pressure relief chamber 5. The pressure relief valve 50 is designed to open to reduce the pressure within the pressure relief chamber 5 in the event of thermal runaway of the target battery cell. Optionally, an opening 51 is provided on the side wall of the housing 1, and the pressure relief valve 50 is mounted in the opening 51.

[0040] By using the convex body to form a pressure relief channel, the air pressure will be discharged to the outside of the battery pack along the pressure relief channel when the battery cell experiences thermal runaway, reducing the risk of thermal runaway of the battery cell and improving the safety of the vehicle. At the same time, the pressure relief channel is formed by using a part of the cooling component, which can reduce the cost of the battery pack and improve assembly efficiency.

[0041] Figure 7 shows a schematic diagram of the assembled battery pack according to an embodiment of the present application. As shown in Figure 6 , after multiple battery cells 2 are installed within the housing 1 and foam glue 4 is encapsulated between the battery cells 2, between the battery cells 2 and the cooling assembly 3, and between the battery cells 2 and the sidewalls of the housing 1, the assembled battery pack shown in Figure 7 is obtained. The liquid inlet pipe 33 and the liquid outlet pipe 34 can be exposed on the outer surface of the housing 1 to facilitate loading of the cooling medium. The pressure relief valve 50 is located on the outer surface of the housing 1 for easy opening.

[0042] In summary, the embodiment of the present application arranges the cooling assembly on the side of the battery cells along the arrangement direction of the multiple battery cells, and arranges a cooling body and at least one protrusion connected to the cooling body in the cooling assembly, so that the cooling body abuts against the multiple battery cells, and the protrusion abuts against the box body and is inserted into the pressure relief cavity. The protrusion can be used to support the battery cells and the cooling body, enhance the structural strength of the battery pack, improve the uniformity of the battery cell temperature, and at the same time guide the heat diffusion after thermal runaway of the battery cell, thereby improving safety, reducing the cost of the battery pack, and improving assembly efficiency.

Claims

1. A battery pack, comprising: A box body (1) is provided with a cavity for accommodating a plurality of battery cells (2) and a pressure relief cavity (5) corresponding to an explosion-proof valve (60) of the battery cells (2); Multiple battery cells (2); at least one cooling assembly (3), the cooling assembly (3) being arranged on a side of the battery cell (2) along an arrangement direction of the plurality of battery cells (2); The cooling assembly (3) comprises a cooling body (31) and at least one protrusion (32) connected to the cooling body (31); the cooling body (31) abuts against a plurality of the battery cells (2) in a corresponding row; and the protrusion (32) is inserted into the pressure relief chamber (5).

2. The battery pack according to claim 1, wherein: The convex body (32) abuts against the box body (1).

3. The battery pack according to claim 1, wherein: The cooling body (31) and at least one protrusion (32) are arranged along the height direction of the battery cells (2), wherein two adjacent rows of the battery cells (2) are arranged in a staggered manner, and two adjacent cooling components (3) are respectively located on both sides of two adjacent rows of the battery cells (2).

4. The battery pack according to claim 1, wherein: The cooling body (31) comprises: A first sub-body (311), wherein the first sub-body (311) extends along a row direction in which the plurality of battery cells (2) are arranged.

5. The battery pack according to claim 4, wherein: The first sub-body (311) is a serpentine structure, and the first sub-body (311) comprises: A plurality of first curved surfaces (3111), wherein the plurality of first curved surfaces (3111) are attached to the side portions of the battery cells (2) in corresponding rows.

6. The battery pack according to claim 5, wherein: The convex body (32) comprises: first convex portion (321); The second convex portion (322) is connected to the first convex portion (321), and the first convex portion (321) and the second convex portion (322) are respectively connected to two adjacent first arc surfaces.

7. The battery pack according to claim 6, wherein: The bending direction of the first arc surface connected to the first convex portion (321) is opposite to the bending direction of the first arc surface connected to the second convex portion (322).

8. The battery pack according to claim 6, wherein: The first convex portion (321) and the second convex portion (322) are both provided with a second arc surface (3221), and the bending direction of the second arc surface is the same as the bending direction of the first arc surface connected to the second arc surface.

9. The battery pack according to claim 4, wherein: The cooling body (31) further comprises: Second sub-ontology (312); The third sub-body (313), the second sub-body (312) and the third sub-body (313) are respectively arranged at two ends of the first sub-body (311), and the second sub-body (312) has at least one connecting hole (3121) for passing a cooling pipe.

10. The battery pack according to any one of claims 1 to 9, wherein: A foam glue (4) is encapsulated between the cooling body (31) and the plurality of battery cells (2), and the foam glue (4) is configured to bond the cooling body (31) and the plurality of battery cells (2).

11. The battery pack according to any one of claims 1 to 9, wherein: A pressure relief valve (50) is provided on the side wall of the box body (1), the pressure relief valve (50) being in communication with the pressure relief chamber (5), and the pressure relief valve (50) being configured to open when the target cell is in thermal runaway to reduce the air pressure in the pressure relief chamber (5).

12. The battery pack according to any one of claims 1 to 9, wherein: The cooling body (31) and the convex body (32) are arranged integrally.

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