Battery pack with thermal runaway protection function

Abstract

The utility model discloses a battery pack with a thermal runaway protection function, and the battery pack comprises a box body which is internally provided with a containing cavity; the battery module is arranged in the accommodating cavity of the box body; the electrical part is arranged in the accommodating cavity of the box body, and the electrical part is positioned at one side part of the battery module; the protection assembly covers the battery module, so that an isolation space is formed in the accommodating cavity above the protection assembly, and a plurality of through holes are formed in the top end, corresponding to the battery module, of the protection assembly; and the anti-explosion valve is arranged at one end, far away from the electrical part, of the box body, and the anti-explosion valve is arranged corresponding to the isolation space. By arranging the isolation space and the anti-explosion valve corresponding to the isolation space, dust substances, electrolyte, high-temperature gas and the like which are erupted during thermal runaway can quickly reach the isolation space and are released out of the battery pack through the anti-explosion valve, so that the insulativity of the interior of the battery pack under thermal runaway is ensured.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery pack with thermal runaway protection function. Background Technology

[0002] Lithium-ion batteries or sodium-ion batteries are widely used in power batteries and energy storage, including residential energy storage, commercial and industrial energy storage, energy storage power stations, and marine energy storage. As their applications become more widespread, their safety requirements are also becoming increasingly stringent. National and industry standards for different application areas have clearly stipulated safety requirements. In particular, the recently released GB / T36276-2023 and GB / T44265-2024 documents have added requirements for battery modules and battery systems to maintain their insulation after thermal runaway.

[0003] Battery modules typically refer to battery packs of varying sizes and specifications, each with an independent sealing design. Their insulation is primarily achieved through the following methods: first, the battery pack assembly design considers electrical clearances and creepage distances, generally employing redundant design; second, the selection of battery pack components considers insulation withstand voltage requirements, such as the insulation protection requirements for cell insulation films, electrical components, and high and low voltage wiring harnesses. These two insulation designs only meet the insulation requirements during factory manufacturing and normal use, and cannot meet the insulation requirements in the event of thermal runaway. After thermal runaway, the electrolyte and internal substances erupt and rapidly fill the entire battery pack, compromising insulation.

[0004] The battery module and battery pack with thermal runaway protection, disclosed in publication number CN219959224U, features perforated structures in all its casings, protective plates, and covers. This allows high-temperature gases to be instantly released to the outside of the module, effectively slowing the rate of internal heat diffusion and significantly reducing the risk of thermal runaway in other cells or even other modules. However, its protective structure only rapidly releases high-temperature gases into the space within the battery pack above the protective structure; it does not promptly expel the high-temperature gases and ejected electrolyte from the battery pack. Therefore, the accumulation of high-temperature gases and ejected electrolyte within the battery pack can still affect insulation and lead to continuous thermal runaway. Utility Model Content

[0005] To address the aforementioned deficiencies in the prior art, the purpose of this application is to provide a battery pack with thermal runaway protection. By setting up an isolation space and a corresponding explosion-proof valve for the isolation space, it is possible to ensure that dust, electrolyte, high-temperature gas, etc., ejected during thermal runaway can quickly reach the isolation space and be released outside the battery pack through the explosion-proof valve, thereby ensuring the insulation of the battery pack's interior under thermal runaway conditions.

[0006] This application provides a battery pack with thermal runaway protection function, including:

[0007] The box contains a cavity.

[0008] The battery module is located inside the housing cavity of the casing.

[0009] Electrical components are housed within the enclosure of the housing and are located on one side of the battery module.

[0010] The protective component covers the battery module, forming an isolation space in the cavity above the protective component. The protective component has several through holes at the top of the battery module.

[0011] An explosion-proof valve is located at the end of the enclosure away from electrical components, and the explosion-proof valve is installed in a corresponding isolated space.

[0012] In a preferred embodiment, the battery module in this application includes a battery module and electrical connectors. The electrical connectors include a BMS board. The battery module includes a plurality of stacked battery cells. Each battery cell has a pressure relief valve at its top. The number of through holes and the pressure relief valves are equal and their positions correspond one-to-one. The battery module is connected to the BMS board through the electrical connectors.

[0013] In a preferred embodiment, the ratio of the size of the pressure relief valve to the size of the through hole is 1 to 1.03.

[0014] In a preferred embodiment, the protective component in this application includes an insulating bracket and a heat-insulating film disposed around the insulating bracket. The insulating bracket covers the top of the battery module, and several through holes are formed on the insulating bracket. The insulating bracket and the heat-insulating film around it cover the top and sides of the battery module.

[0015] In a preferred embodiment, in this application, the insulating support protrudes toward the battery module to form a boss, the end face of the boss contacts the top of the battery module, and several through holes are formed on the boss.

[0016] In a preferred embodiment, the heat insulation film in this application includes a first-end heat insulation film, a second-end heat insulation film, and two side heat insulation films. The first-end heat insulation film is disposed adjacent to the insulating bracket at the top of the battery module and close to the electrical components. The second-end heat insulation film is disposed on the side of the battery module away from the electrical components. The two side heat insulation films are disposed opposite each other on the two sides of the adjacent electrical components of the battery module.

[0017] In a preferred embodiment, in this application, both the insulating bracket and the heat insulation film are bonded and fixed to the battery module with foam adhesive. The opposite sides of the insulating bracket, the top of the second heat insulation film, and the tops of the two side heat insulation films all extend beyond the corresponding ends of the battery module and are all bent toward the battery module to cover the corresponding edge of the battery module.

[0018] In a preferred embodiment, the bottom of the battery module is provided with a liquid cooling plate, and a manifold is provided on the liquid cooling plate corresponding to the peripheral edge of the battery module.

[0019] In a preferred embodiment, the depth and width of the manifold are both 1 to 3 mm, and the ratio of the size of the manifold to the size of the battery module is 0.9 to 1.1.

[0020] In a preferred embodiment, the box body includes a bottom plate and a lid, with the lid covering the bottom plate to form a receiving cavity, and the inner wall of the lid having a high-temperature resistant coating.

[0021] The battery pack with thermal runaway protection provided in this application has the following technical advantages:

[0022] The protective component covers the battery module to isolate the space above it. With several through-holes on the top of the battery module corresponding to the protective component, dust, electrolyte, and high-temperature gases ejected from the battery module during thermal runaway can quickly pass through these through-holes to reach the isolated space. Furthermore, an explosion-proof valve, positioned in the isolated space and away from electrical components, allows the ejected dust, electrolyte, and high-temperature gases to quickly break through the valve and be released outside the battery pack without contaminating the battery module or electrical components. This ensures the insulation of the battery pack, meeting the insulation requirements for battery modules and battery systems after thermal runaway as specified in GB / T36276-2023 and GB / T44265-2024, thus enhancing personnel safety against electric shock. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the battery pack structure of this application;

[0024] Figure 2 This is a structural schematic diagram of the battery pack from another perspective in this application;

[0025] Figure 3 This is an exploded view of the battery pack of this application;

[0026] Figure 4 This is an exploded view of the internal structure of the battery pack in this application;

[0027] Figure 5 A top view comparison of the dimensions of the pressure relief valve and the through-hole in this application;

[0028] Figure 6 This is an enlarged view of the insulating support and a portion thereof in this application;

[0029] Figure 7 This is a schematic diagram of the liquid cooling plate of this application;

[0030] Figure 8This is a partial enlarged view of the liquid cooling plate of this application.

[0031] Figure label:

[0032] 1. Housing; 11. Base plate; 12. Cover; 2. Battery module; 21. Battery module; 211. Battery cell; 212. Pressure relief valve; 22. Electrical connector; 3. Electrical components; 31. BMS board; 4. Protective components; 41. Insulating bracket; 411. Through hole; 412. Boss; 42. First end heat insulation film; 43. Second end heat insulation film; 44. Side heat insulation film; 5. Explosion-proof valve; 6. Foam adhesive; 7. Liquid cooling plate; 71. Manifold. Detailed Implementation

[0033] To better understand and implement this application, the technical solutions in this application will be clearly and completely described below with reference to the accompanying drawings.

[0034] In the description of this application, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0036] See Figure 1-4 This application provides a battery pack with thermal runaway protection, including: a housing 1, a battery module 2, electrical components 3, a protective assembly 4, and an explosion-proof valve 5. Taking a square-structured battery pack as an example, the housing 1 has a square structure and a receiving cavity inside. The battery module 2 is located inside the receiving cavity of the housing 1, and the battery module 2 is generally close to the rear of the housing 1. The electrical components 3 are located inside the receiving cavity of the housing 1, and the electrical components 3 are located on one side of the battery module 2 and at the head of the housing 1.

[0037] Based on this structure, the protective component 4 is placed over the battery module 2 to form an isolation space in the cavity above the protective component 4. The protective component 4 has several through holes 411 corresponding to the top of the battery module 2. The explosion-proof valve 5 is located at the end of the housing 1 away from the electrical components 3, and the explosion-proof valve 5 is positioned corresponding to the isolation space, that is, the explosion-proof valve 5 is located at the upper end of the rear of the housing 1, preferably in the middle area.

[0038] Based on this, the protective component 4 is installed on the battery module 2 to isolate the upper part of the battery module 2 into an isolation space. In conjunction with the several through holes 411 opened on the top of the battery module 2 corresponding to the protective component 4, in the event of thermal runaway, dust, electrolyte, high-temperature gas, etc. ejected from the battery module 2 can quickly pass through the several through holes 411 to reach the isolation space. In addition, with the explosion-proof valve 5 set in the corresponding isolation space and far away from the electrical components 3, the dust, electrolyte, high-temperature gas, etc. ejected into the isolation space can quickly break through the explosion-proof valve 5 and be released outside the battery pack without contaminating the battery module 2 and the electrical components 3. This ensures the insulation of the battery pack and meets the insulation requirements of battery modules and battery systems after thermal runaway in GB / T36276-2023 and GB / T44265-2024, which is conducive to strengthening personnel electric shock protection safety.

[0039] Specifically, battery module 2 includes battery module 21 and electrical connector 22. Electrical component 3 includes BMS board 31. Battery module 21 includes several stacked cells 211. Each cell 211 has a pressure relief valve 212 at its top. The number of through holes 411 and pressure relief valves 212 are equal and their positions correspond one-to-one. Battery module 21 is connected to electrical component 3, such as BMS board 31, through electrical connector 22. Taking a square cell 211 as an example, battery module 21 generally has two or more battery rows arranged side by side. Each battery row includes multiple stacked cells 211 with large surface contact. The top of several cells 211 is provided with a positive terminal, a negative terminal, and a pressure relief valve 212. The positive and negative terminals of cells 211 are connected in series and parallel through aluminum busbars, etc., and are connected to electrical component 3, such as BMS board 31, through electrical connector 22 to realize communication and signal transmission within the battery pack.

[0040] The number of through holes 411 is equal to the number of battery cells 211, and the positions of the through holes 411 correspond one-to-one with the positions of the pressure relief valves 212 of the battery cells 211. This allows the dust, electrolyte, high-temperature gas, etc. inside the battery cell 211 to break through the pressure relief valves 212 and be directly and quickly ejected through the corresponding through holes 411 to the isolation space above the protective component 4, and break through the explosion-proof valve 5 to be released outside the battery pack, so as to ensure the insulation of the battery module 2 and electrical components 3 inside the battery pack.

[0041] Combination Figure 5The ratio of the size of the pressure relief valve 212 to the size of the through hole 411 is 1 to 1.03. That is, the ratio of the length L1 of the pressure relief valve 212 to the length L2 of the through hole 411, and the ratio of the width D1 of the pressure relief valve 212 to the width D2 of the through hole 411 are both 1 to 1.03, and the size of the through hole 411 is slightly smaller than the size of the pressure relief valve 212. This is because when the battery cell 211 experiences thermal runaway, it generally will not completely break through the pressure relief valve 212, but rather break through the middle area of ​​the pressure relief valve 212. The fact that the size of the through hole 411 is slightly smaller than the size of the pressure relief valve 212 ensures that, in the event of thermal runaway, dust, electrolyte, high-temperature gases, etc., inside the battery cell 211 can break through the pressure relief valve 212 and completely pass through the through hole 411, while preventing backflow from the through hole 411 to the top surface of the battery module 2, thus avoiding contamination of the battery module 2 and ensuring its insulation.

[0042] Combination Figure 3 and Figure 4 The protective component 4 includes an insulating bracket 41 and a heat-insulating film disposed around the insulating bracket 41. The insulating bracket 41 covers the top of the battery module 2, and several through holes 411 are formed on the insulating bracket 41. The insulating bracket 41 and the heat-insulating film around it cover the top and sides of the battery module 2. The protective component 4, through the cooperation of the insulating bracket 41 and the heat-insulating film around it, can completely cover the top of the battery module 2 and the three sides away from the electrical components 3. The heat-insulating film can extend to the top of the electrical components 3 to provide comprehensive protection for the electrical structure inside the battery pack. This ensures that thermal runaway dust, electrolyte, high-temperature gases, etc., ejected into the isolation space will not contaminate the battery module 2 and the electrical components 3.

[0043] The heat insulation film includes a first-end heat insulation film 42, a second-end heat insulation film 43, and two side heat insulation films 44. The first-end heat insulation film 42 is disposed adjacent to the insulating bracket 41 at the top of the battery module 2 and close to the electrical component 3. The second-end heat insulation film 43 is disposed at the side of the battery module 2 away from the electrical component 3. The two side heat insulation films 44 are disposed opposite each other on the two sides of the adjacent electrical component 3 of the battery module 2. The first-end heat insulation film 42 is disposed at the front end of the insulating bracket 41 to cooperate with the insulating bracket 41 to protect the top of the battery module 2. The second-end heat insulation film 43 is disposed at the rear end of the insulating bracket 41 to protect the rear end of the battery module 2. The two side heat insulation films 44 are respectively disposed on the left and right sides of the insulating bracket 41 to protect the left and right sides of the battery module 2, thereby achieving comprehensive protection for the battery module 2.

[0044] The insulating bracket 41, the first end heat insulation film 42, the second end heat insulation film 43, and the two side heat insulation films 44 are all made of PC material, which has excellent structural stability, heat resistance and insulation, and is low in cost and easy to obtain. It can play a good role in high temperature resistance and insulation protection at low cost.

[0045] Furthermore, the insulating bracket 41 and the heat insulation film are both bonded and fixed to the battery module 2 with foam adhesive 6. The opposite sides of the insulating bracket 41, the top of the second end heat insulation film 43, and the tops of the two side heat insulation films 44 all extend beyond the corresponding ends of the battery module 2 and are all bent toward the battery module 2 to cover the corresponding edge of the battery module 2. The insulating bracket 41, the first end heat insulation film 42, the second end heat insulation film 43, and the two side heat insulation films 44 are all bonded and fixed to the battery module 2 with foam adhesive 6. The left and right sides of the insulating bracket 41 extend beyond the left and right sides of the battery module 2 and bend downward to cover and adhere to the left and right upper ends of the battery module 2. The top of the second end heat insulation film 43 extends beyond the top of the battery module 2 and bends forward to cover and adhere to the rear upper end of the battery module 2. Then, the tops of the two side heat insulation films 44 extend beyond the top of the battery module 2 and bend toward each other to cover the left and right top ends of the battery module 2. Based on this, the insulating bracket 41, the first end heat insulation film 42, the second end heat insulation film 43, and the two side heat insulation films 44 can stably fit and cover the battery module 2, so as to ensure that the dust, electrolyte, high temperature gas, etc. ejected by thermal runaway reach the isolation space and avoid contaminating the battery module 2 and electrical components 3.

[0046] At the same time, combined Figure 6 An insulating bracket 41 protrudes towards the battery module 2 to form a boss 412. The end face of the boss 412 contacts the top of the battery module 2, and several through holes 411 are formed on the boss 412. The boss 412 can be elongated and arranged in a row corresponding to the pressure relief valves 212 of the battery module 21, so that the boss 412 fits tightly against the position of the pressure relief valve 212 on the battery module 2. This allows dust, electrolyte, high-temperature gas, etc. in the thermal runaway cell 211 to be accurately ejected into the isolation space through the corresponding through holes 411 after breaking through the pressure relief valve 212, thereby avoiding contamination and corrosion of the battery module 2 and electrical components 3.

[0047] In addition, combined Figure 3-4 , Figure 7-8 The bottom of the battery module 2 is provided with a liquid cooling plate 7, and a manifold 71 is opened on the peripheral edge of the liquid cooling plate 7 corresponding to the battery module 2. The liquid cooling plate 7 not only has the function of heat exchange and cooling, but the manifold 71 also allows dust, electrolyte and other substances overflowing from the edge of the protective component 4 to be collected in the manifold 71, preventing them from spreading and thus avoiding contamination and corrosion of the battery module 2 and electrical components 3.

[0048] The manifold 71 has a depth and width of 1–3 mm, and its size is 0.9–1.1 times that of the battery module 2. With the manifold 71's depth and width both being 1–3 mm, the ratio of its overall length L3 to the overall length L4 of the battery module 2 is 0.9–1.1, and the ratio of its overall width D3 to the overall width D4 of the battery module 2 is 0.95–1.05. Thus, the size of the manifold 71 is slightly smaller than that of the battery module 2, ensuring that electrolyte overflowing along the edge of the protective component 4 is smoothly collected in the manifold 71, while also preventing contamination of the battery module 2 and electrical components 3.

[0049] In addition, combined Figure 1-3 The housing 1 includes a base plate 11 and a cover 12. The cover 12 is placed on the base plate 11 to form a receiving cavity, and the inner wall of the cover 12 is provided with a high-temperature resistant coating. The high-temperature resistant coating can further improve the high-temperature resistance of the battery pack.

[0050] The technical means disclosed in this application are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. A battery pack with thermal runaway protection function, characterized in that, include: Box (1), wherein the box (1) is provided with a receiving cavity; Battery module (2), wherein the battery module (2) is disposed within the receiving cavity of the housing (1); Electrical component (3) is disposed in the receiving cavity of the housing (1) and the electrical component (3) is located on one side of the battery module (2); A protective component (4) is provided on the battery module (2) to form an isolation space in the receiving cavity above the protective component (4). The protective component (4) has several through holes (411) corresponding to the top of the battery module (2). An explosion-proof valve (5) is provided at one end of the housing (1) away from the electrical component (3), and the explosion-proof valve (5) is provided corresponding to the isolation space.

2. The battery pack with thermal runaway protection function according to claim 1, characterized in that: The battery module (2) includes a battery module (21) and an electrical connector (22). The electrical connector (3) includes a BMS board (31). The battery module (21) includes a plurality of stacked cells (211). The top of each cell (211) is provided with a pressure relief valve (212). The number of through holes (411) and the number of pressure relief valves (212) are equal and their positions correspond one-to-one. The battery module (21) is connected to the BMS board (31) through the electrical connector (22).

3. The battery pack with thermal runaway protection function according to claim 2, characterized in that: The ratio of the size of the pressure relief valve (212) to the size of the through hole (411) is 1 to 1.

03.

4. The battery pack with thermal runaway protection function according to any one of claims 1-3, characterized in that: The protective component (4) includes an insulating bracket (41) and a heat insulation film disposed around the insulating bracket (41). The insulating bracket (41) covers the top of the battery module (2). A plurality of through holes (411) are formed on the insulating bracket (41). The insulating bracket (41) and the heat insulation film around it cover the top and sides of the battery module (2).

5. The battery pack with thermal runaway protection function according to claim 4, characterized in that: The insulating bracket (41) protrudes toward the battery module (2) to form a boss (412), the end face of the boss (412) is in contact with the top of the battery module (2), and a plurality of through holes (411) are formed on the boss (412).

6. The battery pack with thermal runaway protection function according to claim 4, characterized in that: The heat insulation film includes a first end heat insulation film (42), a second end heat insulation film (43), and two side heat insulation films (44). The first end heat insulation film (42) is disposed adjacent to the insulating bracket (41) at the top of the battery module (2) and close to the electrical component (3). The second end heat insulation film (43) is disposed on the side of the battery module (2) away from the electrical component (3). The two side heat insulation films (44) are disposed opposite each other on the two sides of the adjacent electrical component (3) of the battery module (2).

7. The battery pack with thermal runaway protection function according to claim 6, characterized in that: The insulating bracket (41) and the heat insulation film are both bonded and fixed to the battery module (2) by foam adhesive (6). The opposite sides of the insulating bracket (41), the top of the second end heat insulation film (43), and the top of the two side heat insulation films (44) all extend beyond the corresponding ends of the battery module (2) and are all bent toward the battery module (2) to cover the corresponding edge of the battery module (2).

8. The battery pack with thermal runaway protection function according to any one of claims 1-3, characterized in that: The bottom of the battery module (2) is provided with a liquid cooling plate (7), and the liquid cooling plate (7) is provided with a manifold (71) corresponding to the peripheral edge of the battery module (2).

9. The battery pack with thermal runaway protection function according to claim 8, characterized in that: The depth and width of the manifold (71) are both 1 to 3 mm, and the ratio of the size of the manifold (71) to the size of the battery module (2) is 0.9 to 1.

1.

10. The battery pack with thermal runaway protection function according to any one of claims 1-3, characterized in that: The box body (1) includes a bottom plate (11) and a box cover (12). The box cover (12) is placed on the bottom plate (11) to form the receiving cavity. The inner wall of the box cover (12) is provided with a high temperature resistant coating.

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