Battery module

Abstract

A battery module. The battery module comprises a box body (1), a battery cell assembly (2), an upper cover (3) and a BMS board (4), wherein the battery cell assembly (2) is disposed in the box body (1), the BMS board (4) is installed in the upper cover (3), an opening is provided on the box body (1), and the upper cover (3) covers the opening; and the battery cell assembly (2) comprises a support (21) and battery cells (22) disposed in the support (21), and the BMS board (4) is located on the support (21) and is electrically connected to the battery cells (22). The battery module further comprises a protective member (8), wherein the protective member (8) is connected into the upper cover (3), the battery cells (22) perform spraying towards an outer side surface of the protective member (8), and the protective member (8) is circumferentially disposed on an outer side of the BMS board (4) and abuts against the support (21), so as to separate the BMS board (4) from the battery cells (22). The battery module separates a BMS board (4) from battery cells (22) by means of a protective member (8) and a support (21), such that the BMS board (4) and the battery cells (22) can be effectively protected, thereby improving the safety of the battery cells (22) during thermal runaway; and it can also be ensured that the battery module has a small occupied area and a compact structure.

Description

battery module

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on April 3, 2024, with application number 202420687540.0. 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 protection technology, and in particular to a battery module. Background Art

[0003] In cylindrical battery modules, to prevent thermal interactions between the cylindrical cells and the Battery Management System (BMS) board, two separate chambers are typically placed within the module housing. This allows the cylindrical cells and the BMS board to be physically separated. The BMS board is the circuit board used to monitor and protect the cylindrical cells.

[0004] However, due to the above-mentioned separation method of the two cavities, a larger box body is required, which makes the entire cylindrical battery module occupy a larger area and results in poor structural compactness inside the box body. Technical issues

[0005] The present application provides a battery module that can improve the safety of battery cells during thermal runaway, while ensuring that the battery module occupies a small area and has a compact structure. Solution

[0006] In a first aspect, an embodiment of the present application provides a battery module, comprising a box, a cell assembly, a top cover, and a BMS board, wherein the cell assembly is disposed within the box, the BMS board is mounted within the top cover, the box is provided with an opening, and the top cover is disposed over the opening; the cell assembly comprises a bracket and a cell disposed within the bracket, the BMS board is located on the bracket and electrically connected to the cell, and the battery module further comprises:

[0007] A protective member is connected to the inside of the upper cover, and the battery cells are ejected toward the outer side of the protective member. The protective member is arranged around the outer side of the BMS board and abuts against the bracket to separate the BMS board and the battery cells. Beneficial effects

[0008] By installing the BMS board in the upper cover and locating it on the bracket of the battery cell assembly, and the battery cell spraying toward the outer side of the protective part, and then arranging a protective part in the upper cover, the protective part is arranged around the outer side of the BMS board and abuts against the bracket, so that the BMS board and the battery cell can be completely separated by the protective part and the bracket; when the battery cell has thermal runaway and generates high-temperature and high-pressure gas, the isolation effect of the bracket and the protective part prevents the generated gas from being sprayed to the BMS board, ensuring that the BMS board is not damaged, so that the BMS board can promptly report the thermal runaway alarm signal, buy a certain amount of time for escape, and thus improve safety during thermal runaway; at the same time, the heat generated by the BMS board during operation is isolated to prevent the battery cell from being heated, so as to better protect the battery cell and thus increase the service life of the battery cell; by arranging a protective part between the bracket of the battery cell assembly and the upper cover, compared with directly arranging two separated cavities in the box body, a larger box body is not required, so that the structure of the entire box body occupies a smaller area and has a more compact structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG1 is a schematic structural diagram of a battery module provided in this application;

[0010] FIG2 is a schematic diagram of the exploded structure of the battery module provided in this application;

[0011] FIG3 is a schematic diagram of the assembly structure between the protective member and the bracket provided in the present application;

[0012] FIG4 is a schematic structural diagram of the upper cover and the protective member when not assembled at one viewing angle provided by the present application;

[0013] FIG5 is a schematic structural diagram of the upper cover and the protective member when not assembled, provided by the present application, from another perspective.

[0014] Description of reference numerals:

[0015] 1-Box; 2-Cell assembly; 21-Bracket; 22-Cell; 221-Injection end; 3-Upper cover; 31-Mounting block; 4-BMS board; 5-Pole; 6-Bus; 7-Explosion-proof valve;

[0016] 8-protective part; 81-U-shaped plate; 82-notch plate; 821-avoidance notch. Modes for Carrying Out the Invention

[0017] This embodiment provides a battery module that can improve thermal runaway safety while ensuring a compact structure and a small footprint for the entire battery module. In this embodiment, the battery module is a 12V cylindrical battery module.

[0018] As shown in Figures 1 and 2, the battery module includes a case 1, a cell assembly 2, a top cover 3 and a BMS board 4. The cell assembly 2 is arranged in the case 1, and the BMS board 4 is installed in the top cover 3. An opening is provided on the case 1, and the top cover 3 is provided at the opening so that the cell assembly 2 and the BMS board 4 can be encapsulated in the case 1; the cell assembly 2 includes a bracket 21 and a cell 22 arranged in the bracket 21, and the BMS board 4 is placed horizontally on the bracket 21, and the BMS board 4 is electrically connected to the cell 22. The BMS board 4 and the cell 22 in this embodiment are common structures in existing battery modules, and their working principles are not described here. The BMS board 4 is connected to the top cover 3 by fasteners. In this embodiment, the fasteners can be bolts.

[0019] As shown in Figures 2 to 5, the battery module also includes a protective member 8. The battery cells 22 are ejected toward the outer side of the protective member 8. The protective member 8 is connected to the inside of the upper cover 3. The protective member 8 is arranged around the outside of the BMS board 4 and abuts against the bracket 21. The BMS board 4 and the battery cells 22 can be separated by the mutually abutting bracket 21 and upper cover 3. In this embodiment, the battery cells 22 are cylindrical cells, which are placed horizontally in the box body 1.

[0020] Compared with the related art, the battery module in this embodiment changes the physical separation structure between the BMS board 4 and the battery cell 22; by installing the BMS board 4 in the upper cover 3 and horizontally placing it on the bracket 21 of the battery cell assembly 2, and then providing a protective member 8 in the upper cover 3, and allowing the battery cell 22 to be ejected toward the outer side of the protective member 8, so that the protective member 8 is arranged around the outer side of the BMS board 4 and abuts against the bracket 21, so that the BMS board 4 and the battery cell 22 can be completely separated by the protective member 8 and the bracket 21; when the battery cell 22 has thermal runaway and generates high-temperature and high-pressure gas, the generated gas is prevented from being heated due to the isolation effect of the bracket 21 and the protective member 8. The spray is sprayed onto the BMS board 4 to ensure that the BMS board 4 is not damaged, so that the BMS board 4 can report the thermal runaway alarm signal in time, buy a certain amount of time for escape, and thus improve the safety during thermal runaway; at the same time, the heat generated by the BMS board 4 during operation is isolated to prevent the battery cell 22 from being heated, so as to better protect the battery cell 22, thereby increasing the service life of the battery cell 22; a protective member 8 is provided between the bracket 21 of the battery cell assembly 2 and the upper cover 3. Compared with directly providing two separated cavities in the box body 1, a larger volume of the box body 1 is not required, so that the structure of the entire box body 1 occupies a smaller area and has a better compact structure.

[0021] The protective member 8 and the upper cover 3 are integrally formed, that is, they are integrally injection molded. This simplifies and facilitates processing, eliminating the need for additional assembly of the protective member 8 and the upper cover 3, saving time and effort. Furthermore, it ensures a tight seal between the protective member 8 and the upper cover 3, preventing heat generated by the operation of the BMS board 4 and high-temperature, high-pressure gases generated by thermal runaway of the battery cells 22 from flowing out or in through the gap between the upper cover 3 and the protective member 8, thereby ensuring a separation between the BMS board 4 and the battery cells 22. In other embodiments, the upper cover 3 and the protective member 8 may also be separate structures, which is not a limitation here.

[0022] It is worth noting that since the upper cover 3 is usually made of plastic material, the protective member 8 which is an integrally molded structure with the upper cover 3 is also made of plastic material. When heat or high-temperature and high-pressure gas flows to the protective member 8, it is easy to melt the protective member 8 quickly in a short period of time and damage the BMS board 4, resulting in the BMS board 4 inside the protective member 8 being unable to report the thermal runaway alarm signal in time.

[0023] In this embodiment, the upper cover 3 and protective member 8 are integrally injection-molded from polyamide-66 (PA66) with 30% glass fiber (GF). This allows for a higher melting point of the upper cover 3 and protective member 8, ranging from 200°C to 220°C. This prolongs the time between thermal runaway and melting of the protective member 8 (10s-12s), allowing the protective member 8 to melt over a longer period of time, allowing the BMS inside the protective member 8 to generate a thermal runaway alarm signal. PA66, short for polyamide 66 or nylon 66, is a thermoplastic resin material, while GF, short for glass fiber, is an inorganic, non-metallic material with excellent performance.

[0024] As shown in FIG2 , a plurality of spaced-apart battery cells 22 are disposed within the bracket 21, and an arcuate groove configured to accommodate the battery cells 22 is provided within the casing 1. That is, the upper and lower ends of the battery cells 22 are respectively mounted within the bracket 21 and the arcuate groove, to ensure the stability and reliability of the installation of the battery cells 22 within the casing 1. In this embodiment, four battery cells 22 are disposed within the casing 1.

[0025] In order to save the usable space in the box body 1 and make the entire battery module more compact, as shown in Figures 2 and 3, the protective member 8 is directly in contact with the bracket 21, that is, the outer side surface of the protective member 8 is flush with the outer side surface of the bracket 21, the battery cell 22 is perpendicular to the outer side surface of the bracket 21, and a notch is provided on the outer side surface of the bracket 21 for exposing the injection end 221 of the battery cell 22, that is, the explosion-proof structure of the battery cell 22 is arranged corresponding to the notch, so that the injection end 221 of the battery cell 22 is sprayed outward toward the outer side surface of the protective member 8, so as to ensure that the protective member 8 can block the high-temperature and high-pressure gas ejected from the injection end 221 of the battery cell 22.

[0026] As shown in Figures 2 to 5, the protective member 8 includes a U-shaped plate 81 and a notch plate 82. The notch plate 82 is located on the open side of the U-shaped plate 81. The U-shaped plate 81 and the notch plate 82 are both directly in contact with the bracket 21. The U-shaped plate 81 and the notch plate 82 can be used to surround the BMS board 4 inside the protective member 8, thereby separating the battery cells 22 from the BMS board 4. The outer side of the U-shaped plate 81 is flush with the outer side of the bracket 21.

[0027] It is worth noting that making the outer side surface of the U-shaped plate 81 flush with the outer side surface of the bracket 21, compared to making the outer side surface of the U-shaped plate 81 protrude outward from the outer side surface of the bracket 21, can ensure that the injection end 221 of the battery cell 22 sprays outward toward the outer side surface of the U-shaped plate 81, thereby increasing the path for the gas ejected from the injection end 221 to reach the U-shaped plate 81, and further providing more time for the protective part 8 to protect the BMS board 4, so as to buy more time for escape.

[0028] As shown in Figures 3 to 5, an avoidance notch 821 is provided on the notch plate 82 to provide an avoidance space for the mounting block 31 on the upper cover 3. That is, the mounting block 31 is located at the avoidance notch 821 to avoid interference between the mounting block 31 and the notch plate 82; the mounting block 31 is configured to mount the pole 5, one end of the pole 5 is electrically connected to the BMS board 4, and the other end of the pole 5 extends out of the top of the upper cover 3.

[0029] As shown in Figures 1 to 3, an explosion-proof valve 7 is provided on the box body 1, so that the high-temperature and high-pressure gas generated by the thermal runaway of the battery cell 22 can be discharged to the outside of the box body 1 through the explosion-proof valve 7 to ensure the safety of thermal runaway; and the explosion-proof valve 7, the notch plate 82 and an injection end 221 of the battery cell 22 are located on the same side of the box body 1.

[0030] By arranging the explosion-proof valve 7, the notch plate 82 and an injection end 221 of the battery cell 22 on the same side of the box body 1, when the injection end 221 of the battery cell 22 ejects gas due to thermal runaway, a large amount of gas will be directly ejected from the explosion-proof valve 7, preventing a large amount of gas from being ejected from the avoidance notch 821 of the notch plate 82 to the BMS board 4, thereby ensuring the isolation and protection effect of the notch plate 82 on the BMS board.

[0031] It is worth noting that, as shown in FIG3 , a U-shaped plate 81 is provided at the other injection end 221 of the battery cell 22 , so that the gas ejected from the injection end 221 can be separated by the U-shaped plate 81 , thereby ensuring the protection effect on the BMS board 4 .

[0032] The connection between the pole 5 and the BMS board 4 is sealed by sealant to avoid the generation of gaps at the connection between the pole 5 and the BMS board 4; the upper cover 3 and the box body 1 are sealed by sealant, and the connecting wires connected to the BMS board 4 are sealed and passed through the bracket 21, that is, sealant is provided between the connecting wires and the bracket 21, so that the entire battery module can be sealed and connected, avoiding the heat generated by the BMS board 4 and the high-temperature and high-pressure gas generated by the thermal runaway of the battery cell 22 from running around, thereby better protecting the BMS board 4 and the battery cell 22.

[0033] As shown in Figure 2, the battery module also includes a bus 6, one end of the bus 6 is electrically connected to the BMS board 4, and the other end of the bus 6 is electrically connected to the battery cell 22. That is, the current of the battery cell 22 is conducted to the outside of the battery module through the bus 6, the BMS board 4 and the pole 5 in sequence.

[0034] The battery module in this embodiment, through the action of the protective member 8 and the bracket 21, can, on the one hand, isolate the thermal runaway gas of the battery cell 22 from the BMS board 4, ensuring that the BMS board 4 is not damaged so that a thermal runaway alarm signal can be reported in time, thereby buying time for escape; on the other hand, it can isolate the heat generated by the operation of the BMS board 4, preventing the battery cell 22 from being heated, thereby improving the service life and performance of the battery cell 22.

Claims

1. A battery module, comprising a box (1), a battery cell assembly (2), an upper cover (3) and a battery management system (BMS) board (4), wherein the battery cell assembly (2) is arranged in the box (1), the BMS board (4) is installed in the upper cover (3), the box (1) is provided with an opening, and the upper cover (3) is arranged to cover the opening; the battery cell assembly (2) comprises a bracket (21) and a battery cell (22) arranged in the bracket (21), the BMS board (4) is located on the bracket (21) and is electrically connected to the battery cell (22), and the battery module further comprises: A protective member (8) is connected to the inside of the upper cover (3), the battery cell (22) is ejected toward the outer side of the protective member (8), and the protective member (8) is arranged around the outer side of the BMS board (4) and abuts against the bracket (21) to separate the BMS board (4) and the battery cell (22).

2. The battery module according to claim 1, wherein: The protective member (8) and the upper cover (3) are an integrally formed structure.

3. The battery module according to claim 2, wherein: The melting point of the protective element (8) is in the range of 200°C to 220°C.

4. The battery module according to any one of claims 1 to 3, wherein: The outer side surface of the protective member (8) is flush with the outer side surface of the bracket (21); a notch is provided on the outer side surface of the bracket (21) for exposing the injection end (221) of the battery cell (22); and the explosion-proof structure of the battery cell (22) is arranged corresponding to the notch.

5. The battery module according to any one of claims 1 to 3, wherein: The protective element (8) comprises: A U-shaped plate (81) and a notch plate (82), wherein the notch plate (82) is located at the opening side of the U-shaped plate (81), an avoidance notch (821) is provided on the notch plate (82), and the U-shaped plate (81) and the notch plate (82) are both in contact with the bracket (21).

6. The battery module according to claim 5, wherein: An explosion-proof valve (7) is provided on the box body (1); the explosion-proof valve (7), the notch plate (82) and the injection end (221) of the battery cell (22) are located on the same side of the box body (1).

7. The battery module according to claim 5, wherein: The upper cover (3) is further provided with a mounting block (31), the mounting block (31) being configured to mount a pole (5), the pole (5) being electrically connected to the BMS board (4), and the mounting block (31) being located at the avoidance notch (821).

8. The battery module according to claim 7, wherein: The pole (5) is sealedly connected to the BMS board (4).

9. The battery module according to any one of claims 1 to 3, wherein: The upper cover (3) is sealedly connected to the box body (1), and the connecting wire connected to the BMS board (4) passes through the bracket (21) in a sealed manner.

10. The battery module according to any one of claims 1 to 3, further comprising: A busbar (6), one end of the busbar (6) being electrically connected to the BMS board (4), and the other end of the busbar (6) being electrically connected to the battery cell (22).

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