Battery pack

Abstract

Provided is a battery pack that prevents the spread of thermal runaway. 【Solution means】 The battery pack is a battery module including a pair of battery assemblies, each battery assembly including a support tray and a cell group. The support tray is provided with a plurality of through holes, and pressure relief valves of a plurality of single cells in the cell group are arranged in one-to-one correspondence with the plurality of through holes. The pressure relief valves of the pair of cell groups are arranged to face each other. The support tray is provided with a plurality of pressure relief holes. The battery module, a module bracket provided with a first pressure relief passage, a pressure relief cavity is provided between the pair of support trays, and the through holes, the pressure relief cavity, the first pressure relief passage and the pressure relief holes communicate with each other. The module bracket, and a housing, the battery module is provided in the housing, the housing is provided with a third pressure relief passage, and the third pressure relief passage and the pressure relief holes communicate with each other.

Description

Technical Field

[0001] This application claims priority to a Chinese patent application with application number 202211598515.7 filed with the China National Intellectual Property Administration on December 14, 2022, and the entire content of the above application is incorporated herein by reference.

[0002] This application relates to the technical field of battery packs, and particularly to battery packs.

Background Art

[0003] In recent years, the demand for vehicle lightweighting has been increasing. Especially in the field of new energy vehicles, the cruising range has always been a bottleneck restricting performance development. In related technologies, to extend the cruising range, it usually includes increasing the energy density of the battery pack or the number of modules from the perspective of increasing the total energy of the battery. Also, to improve the space utilization rate of electric vehicles, usually two-layer modules are arranged. With the emergence of the two-layer module structure, the envelope space can be effectively utilized, and the cruising range of electric vehicles can be improved.

[0004] In the design process of the related two-layer module battery pack, due to the difficulty of sealing, it is usually difficult to design a dedicated exhaust and pressure relief passage. Since there is no dedicated exhaust and pressure relief passage in the two-layer module battery pack, when thermal runaway occurs in the cells on the module, a large amount of gas and the accompanying flames are instantaneously released inside the cells. Since there is no directional exhaust passage to guide these gas and flames, they spread randomly inside the battery pack, are likely to ignite other components, and thermal runaway also occurs in other normally used cells, thereby causing the thermal runaway to spread and easily leading to fire or explosion, and there is room for improvement.

Summary of the Invention

Means for Solving the Problems

[0005] In one aspect, this application provides a battery pack that prevents the spread of thermal runaway.

[0006] The battery pack includes a battery module including a pair of battery assemblies stacked and arranged along the height direction, wherein each battery assembly includes a support tray and a cell group, a plurality of through holes are provided through the support tray along its height direction, pressure relief valves of a plurality of single cells in the cell group are arranged in one-to-one correspondence with the plurality of through holes, pressure relief valves of a pair of cell groups arranged along the height direction are arranged opposite to each other, and a plurality of pressure relief holes are further provided in the support tray, a battery module, a module bracket arranged between a pair of support trays arranged along the height direction and provided with a first pressure relief passage, a pressure relief cavity is provided between a pair of support trays arranged along the height direction, and the through holes, the pressure relief cavity, the first pressure relief passage and the pressure relief holes communicate with each other, a module bracket, a housing, wherein the battery module is provided in the housing, a third pressure relief passage is provided in the housing, and the third pressure relief passage and the pressure relief holes communicate with each other, including the housing. In one embodiment, each support tray includes a tray body formed with a mounting groove and a tray extension provided at the periphery of the tray body, and a plurality of through holes are provided through the tray body along its height direction,

[0007] a pressure relief cavity is provided between a pair of tray bodies arranged along the height direction, and the module bracket is provided between a pair of tray extensions arranged along the height direction. In one embodiment, both the tray extension and the module bracket are in a rectangular ring shape.

[0008] In one embodiment,

[0009] it further includes a refractory plate provided between a pair of tray bodies arranged along the height direction, and the through holes of the upper tray body and the through holes of the lower tray body are separated by the refractory plate.

[0010] ​ In one embodiment, side beams and a plurality of first cross beams are provided inside the housing. The side beams are combined to form a frame structure. A third pressure relief passage is provided inside the side beams. The plurality of first cross beams are provided inside the frame structure and connected to the side beams. The plurality of first cross beams divide a plurality of regions inside the frame structure, and a battery module is provided in each region.

[0011] In one embodiment, a second pressure relief passage is provided in the first cross beam, and the first pressure relief passage, the pressure relief hole, the second pressure relief passage, and the third pressure relief passage are in communication.

[0012] In one embodiment, a pair of support trays arranged along the height direction are symmetrically arranged, and a plurality of pressure relief holes are provided in the tray extension part located on the lower side. The pressure relief holes, the second pressure relief passage, and the third pressure relief passage are in communication.

[0013] In one embodiment, an explosion-proof valve is provided on the side beam, and the explosion-proof valve is in communication with the third pressure relief passage.

[0014] In one embodiment, the module bracket and a pair of tray extensions arranged along the height direction are connected by a locking part to clamp the fireproof board.

[0015] In summary, the battery pack provided by the embodiments of the present application has the following beneficial effects.

[0016] In actual applications, in the two-layer battery assembly of the battery pack in the embodiments of the present application, the single cell of the battery assembly is a cylindrical cell, and since the pressure relief valve of the cylindrical cell is arranged at the bottom of the cell itself, the two-layer battery assembly has an attachment structure in which the bottoms of the single cells are arranged opposite to each other. When the battery generates heat and gets out of control, the generated gas and flame concentrate in the pressure relief cavity formed between a pair of support trays arranged along the height direction through the through holes. Next, the generated gas and flame flow into the first pressure relief passage of the module bracket, then into the pressure relief holes of the support tray, and finally into the third pressure relief passage of the housing. These gases and flames are guided through the third pressure relief passage, thereby effectively preventing the gases and flames from spreading randomly within the battery pack, effectively preventing the spread of thermal runaway, and preventing more serious fires or explosions.

[0017] Additional aspects and advantages of the present application will be described in part in the following description, will become apparent in part from the following description, or will be understood through the implementation of the present application.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0019] In the description of this application, the directions or positional relationships indicated by terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" are based on the directions or positional relationships shown in the drawings, and are merely for facilitating the description of this application and simplifying the description, and do not imply or suggest that the devices or elements mentioned must have a specific direction and be constructed and operated in a specific direction. Therefore, it cannot be construed as limiting this application.

[0020] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in this specification in the description of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0021] Hereinafter, with reference to FIGS. 1 to 6, a battery pack and a power consumption device according to an embodiment of this application will be described. Hereinafter, some embodiments of this application will be described in detail in conjunction with the accompanying drawings. The following examples and the features in the examples can be combined with each other as long as they do not conflict.

[0022] In recent years, the demand for weight reduction of automobiles has been increasing. Especially in the field of new energy vehicles, the cruising range has always been a bottleneck restricting performance development. In related technologies, the extension of the cruising range usually includes increasing the energy density of the battery pack or the number of modules from the perspective of increasing the total energy of the battery. Also, in order to improve the space utilization rate of electric vehicles, usually two-layer modules are arranged. With the emergence of the two-layer module structure, the envelope space can be effectively utilized, and the cruising range of electric vehicles can be improved.

[0023] In the design process of a related two-layer module battery pack, it is difficult to seal, so it is usually difficult to design a dedicated exhaust and pressure relief passage. Since there is no dedicated exhaust and pressure relief passage in the two-layer module battery pack, when thermal runaway occurs in the cells on the module, a large amount of gas and the accompanying flames are instantaneously released inside the cells. Since there is no directional exhaust passage to guide these gas and flames, they spread randomly inside the battery pack, are likely to ignite other components, and thermal runaway also occurs in other normally used cells, thereby causing the thermal runaway to spread and easily leading to a fire or explosion, and there is room for improvement.

[0024] In view of the above, in the battery pack according to the embodiment of the present application, the two-layer module is provided with a dedicated exhaust and pressure relief structure that guides these gas and flames in a certain direction and prevents the spread of thermal runaway when thermal runaway occurs.

[0025] Specifically, FIGS. 1 to 6 can be referred to. The battery pack according to the embodiment of the present application includes a battery module, a module bracket 2, and a housing 6.

[0026] In one embodiment, the battery module includes a pair of battery assemblies 1 arranged vertically stacked along the height direction. Each battery assembly 1 includes a support tray 11 and a cell group 12. The support tray 11 is provided with a plurality of through holes 111 penetrating along its height direction. The pressure relief valves of the plurality of single cells in the cell group 12 are arranged in one-to-one correspondence with the plurality of through holes 111. The pressure relief valves of the pair of cell groups 12 arranged along the height direction are arranged oppositely. Further, the support tray 11 is provided with a plurality of pressure relief holes 112. The module bracket 2 is arranged between a pair of support trays 11 arranged along the height direction, and the module bracket 2 is provided with a first pressure relief passage 21. A pressure relief cavity 3 is provided between a pair of support trays 11 arranged along the height direction, and the through holes 111, the pressure relief cavity 3, the first pressure relief passage 21, and the pressure relief holes 112 are in communication. The battery module is provided in a housing 6, and the housing 6 is provided with a third pressure relief passage 71, and the third pressure relief passage 71 and the pressure relief holes 112 are in communication.

[0027] In actual application, in the two-layer battery assembly 1 of the battery pack in the embodiment of the present application, the single cell of the battery assembly 1 is a cylindrical cell, and since the pressure relief valve of the cylindrical cell is arranged at the bottom of the cell itself, the two-layer battery assembly 1 has an attachment structure in which the bottoms of the single cells are arranged oppositely. When the battery generates heat and gets out of control, the generated gas and flame concentrate in the pressure relief cavity 3 formed between a pair of support trays 11 arranged along the height direction through the through holes 111. Next, the generated gas and flame flow into the first pressure relief passage 21 of the module bracket 2, then flow into the pressure relief holes 112 of the support tray 11, and finally flow into the third pressure relief passage 71 of the housing 6. These gas and flame are guided through the third pressure relief passage 71, thereby effectively preventing the gas and flame from spreading randomly in the battery pack, effectively preventing the spread of thermal runaway, and preventing more serious fires or explosions.

[0028] In further applications, although the two-layer module configuration within the battery pack can effectively improve the driving range of an electric vehicle, it has been found that the thickness of the battery pack increases. Therefore, in order to reduce the overall thickness of the battery pack, the structure of the support tray 11 is improved, and accordingly, the installation position of the module bracket 2 is also adjusted, thereby reducing the thickness of the battery pack to a certain extent and achieving miniaturization and weight reduction.

[0029] Specifically, reference can be made to FIGS. 1 to 6. In the battery pack according to the embodiment of the present application, each support tray 11 includes a tray body 113 in which a mounting groove is formed and a tray extension 114 provided at the periphery of the tray body 113. A plurality of through holes 111 are provided through the tray body 113 along its height direction. A pressure relief cavity 3 is provided between a pair of tray bodies 113 arranged along the height direction. The module bracket 2 is provided between a pair of tray extensions 114 arranged along the height direction.

[0030] In actual applications, a pair of support trays 11 are provided for the battery module of the battery pack according to the embodiment of the present application. Since the support tray 11 includes a tray body 113 in which a mounting groove is formed, the tray body 113 itself has a certain height, and thereby an installation gap for mounting the module bracket 2 is formed between a pair of tray extensions 114. Therefore, the cell group 12 is mounted corresponding to the mounting groove of the tray body 113, the module bracket 2 is mounted corresponding to the tray extension 114, and the cell group 12 is provided corresponding to the inside of the module bracket 2. Therefore, the heights of the cell group 12 and the module bracket 2 partially overlap, and the structure becomes more compact, which reduces the thickness of the battery pack to a certain extent and achieves miniaturization and weight reduction.

[0031] As can be seen from the above, when the battery generates heat and becomes uncontrollable, the generated gas and flame concentrate in the pressure relief cavity 3. Next, the generated gas and flame flow towards the edge of the support tray 11, flow into the first pressure relief passage 21 of the module bracket 2, further flow into the pressure relief hole 112 of the support tray 11, and finally flow into the third pressure relief passage 71 of the housing 6. These gas and flame are guided through the third pressure relief passage 71, thereby effectively preventing the gas and flame from spreading randomly within the battery pack, effectively preventing the spread of thermal runaway, and preventing more serious fires or explosions.

[0032] Existing battery packs are usually made in a square case shape. To fit the square case shape, the battery pack, tray extension 114, and module bracket 2 in the embodiments of the present invention are all in a rectangular ring shape.

[0033] Of course, in other embodiments, the tray extension 114 and the module bracket 2 may be circular.

[0034] In a further application, due to the two-layer module configuration of the present battery pack, when a single cell in one layer of the cell group 12 undergoes thermal runaway, the generated gas and flame are ejected towards the bottom of the single cell in the opposing cell group 12, and it has been found that this causes further thermal runaway. Therefore, in order to prevent the generated gas and flame from ejecting towards the bottom of the single cell of the opposing module and causing thermal runaway, the present battery pack is provided with a refractory plate 5 that prevents the spread of thermal runaway between the two-layer modules by blocking.

[0035] Specifically, FIGS. 1 to 6 can be referred to. The battery pack in the embodiments of the present application further includes a refractory plate 5. The refractory plate 5 is disposed between a pair of tray bodies 113 arranged in the height direction. The through hole 111 of the upper tray body 113 and the through hole 111 of the lower tray body 113 are separated by the refractory plate 5.

[0036] In actual applications, when a single cell within one layer of cell groups 12 in the battery pack in the embodiments of this application undergoes thermal runaway, the generated gas and flame will eject towards the refractory plate 5, flow along the refractory plate 5 towards the edge of the support tray 11, then flow into the first pressure relief passage 21 of the module bracket 2, further flow into the pressure relief holes 112 of the support tray 11, and finally flow into the third pressure relief passage 71 of the housing 6. These gas and flame are guided through the third pressure relief passage 71, thereby effectively preventing the gas and flame from spreading randomly within the battery pack, effectively preventing the spread of thermal runaway, and preventing more serious fires or explosions. Also, it effectively prevents the generated gas and flame from ejecting towards the bottom of the single cell of the opposing module and causing thermal runaway, and prevents the spread of thermal runaway between the two-layer modules.

[0037] The refractory plate 5 may be a high-temperature resistant mica plate that can be produced by adhering, heating, and pressing mica paper and an organic silicone adhesive. The mica content is about 90%, and the organic silicone adhesive content is 10%.

[0038] In further applications, in order to increase the battery capacity of the battery pack, it has been found that usually, a plurality of battery modules are provided within the battery pack. In this battery pack, the structure of the housing 6 has been improved to enable the generated gas and flame to be reasonably discharged when thermal runaway occurs in the plurality of battery modules.

[0039] Specifically, reference can be made to FIGS. 1 to 6. In the battery pack in the embodiments of this application, within the housing 6, side beams 7 and a plurality of first cross beams 4 are provided. The side beams 7 are combined to form a frame structure, and a third pressure relief passage 71 is provided within the side beams 7. The plurality of first cross beams 4 are provided inside the frame structure and are connected to the side beams 7. The plurality of first cross beams 4 divide a plurality of regions within the frame structure, and battery modules are provided in each region.

[0040] In other embodiments, a second pressure relief passage 41 is provided in the first cross beam 4, and the first pressure relief passage 21, the pressure relief hole 112, the second pressure relief passage 41, and the third pressure relief passage 71 communicate with each other.

[0041] In actual applications, the plurality of battery modules and the plurality of first cross beams 4 in the battery pack according to the embodiments of the present application are alternately arranged at intervals, so that as a result, one battery module is arranged between two first cross beams 4. When the battery generates heat and gets out of control, the generated gas and flame concentrate in the pressure relief cavity 3 formed between a pair of support trays 11 arranged along the height direction through the through hole 111. Next, the generated gas and flame flow into the first pressure relief passage 21 of the module bracket 2, and then into the pressure relief hole 112 of the support tray 11. After that, it first flows into the second pressure relief passage 41 of the first cross beam 4, and then into the third pressure relief passage 71 of the housing 6. These gases and flames are guided through the third pressure relief passage 71, thereby effectively preventing the gases and flames from spreading randomly in the battery pack, effectively preventing the spread of thermal runaway, and preventing more serious fires or explosions.

[0042] Furthermore, from the perspective of position, the gas and flame generated by the battery module flow to the first cross beams 4 on both sides, and then are guided through the second pressure relief passage 41, thereby effectively preventing the gas and flame from spreading randomly in the battery pack, effectively preventing the spread of thermal runaway, and preventing more serious fires or explosions.

[0043] For the structure that guides the flow of the generated gas and flame, specifically, FIGS. 1 to 6 can be referred to. The side beam 7 is provided with exhaust holes, and the exhaust holes communicate with the outside of the housing and the third pressure relief passage 71. The exhaust holes are blocked by explosion-proof valves 72, and the explosion-proof valves 72 communicate with the third pressure relief passage 71. The side beam 7 can specifically be in a concave shape.

[0044] In actual applications, when a thermal runaway occurs in the battery module, the generated gas and flame flow into the second pressure relief passage 41 in the first cross beam 4, then flow into the third pressure relief passage 71 of the side beam 7, and finally flow into the explosion-proof valve 72. The explosion-proof valve 72 automatically opens to relieve the pressure and prevent the explosion of the battery pack 100.

[0045] In a further application, a refractory plate 5 is provided between a pair of tray bodies 113 arranged along the height direction. When a thermal runaway occurs, the generated gas and flame jet towards the refractory plate 5. It has been found that it is necessary to fix the refractory plate 5 so that the jet does not deviate during thermal runaway. This battery pack fixes the refractory plate 5 by a clamping structure.

[0046] Specifically, reference can be made to FIGS. 1 to 6. In the battery pack according to the embodiment of the present application, the module bracket 2 and a pair of tray extension parts 114 arranged along the height direction are connected by a locking part 8 to clamp the refractory plate 5.

[0047] In actual applications, this battery pack locks a pair of tray extension parts 114 to the module bracket 2 via the locking part 8, and further clamps the refractory plate 5 via a pair of tray bodies 113 to achieve the fixation of the refractory plate 5 and prevent the jet from deviating during thermal runaway. Here, the locking part 8 can specifically be a bolt or a screw.

[0048] Embodiments of the present application disclose not only a battery pack but also a power consumption device including the battery pack. The power consumption device can be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, a power tool, an electric bicycle, an electric vehicle, a ship, a spacecraft, etc. The electric toy may include stationary or mobile electric toys such as a game console, an electric vehicle toy, an electric ship toy, and an electric airplane toy. The spacecraft may include an airplane, a rocket, a space shuttle, and a spaceship, etc. The power tool includes power tools for metal cutting, power tools for polishing, power tools for assembly, and power tools for railways, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an electric impact drill, a concrete vibrator, and an electric saw.

Description of Reference Numerals

[0049] 1 - Battery assembly, 11 - Support tray, 111 - Through hole, 112 - Pressure relief hole, 113 - Tray body, 114 - Tray extension, 12 - Cell group, 2 - Module bracket, 21 - First pressure relief passage, 3 - Pressure relief cavity, 4 - First cross beam, 41 - Second pressure relief passage, 5 - Fireproof plate, 6 - Housing, 7 - Side beam, 71 - Third pressure relief passage, 72 - Explosion-proof valve, 8 - Locking portion

Claims

1. A battery pack, comprising: a battery module including a pair of battery assemblies (1) stacked and arranged along the height direction, each of the battery assemblies (1) includes a support tray (11) and a cell group (12), a plurality of through holes (111) are provided through the support tray (11) along its height direction, pressure relief valves of a plurality of single cells in the cell group (12) are arranged in one-to-one correspondence with the plurality of through holes (111), pressure relief valves of a pair of the cell groups (12) arranged along the height direction are arranged opposite to each other, and a plurality of pressure relief holes (112) are further provided in the support tray (11); a battery module, a module bracket (2) arranged between a pair of the support trays (11) arranged along the height direction and provided with a first pressure relief passage (21), a pressure relief cavity (3) is provided between a pair of the support trays (11) arranged along the height direction, and the through holes (111), the pressure relief cavity (3), the first pressure relief passage (21) and the pressure relief holes (112) are in communication with each other; a module bracket (2), a housing (6), the battery module is provided in the housing (6), a third pressure relief passage (71) is provided in the housing (6), and the third pressure relief passage (71) and the pressure relief holes (112) are in communication with each other; a housing (6); a battery pack.

2. Each of the support trays (11) includes a tray body (113) formed with a mounting groove and a tray extension portion (114) provided at a periphery of the tray body (113), and the plurality of through holes (111) are provided through the tray body (113) along its height direction, the pressure relief cavity (3) is provided between a pair of the tray bodies (113) arranged along the height direction, and the module bracket (2) is provided between a pair of the tray extension portions (114) arranged along the height direction; the battery pack according to Claim 1.

3. Both the tray extension portion (114) and the module bracket (2) are in a rectangular ring shape; the battery pack according to Claim 2.

4. The battery pack according to claim 2, further comprising a refractory plate (5) provided between a pair of the tray bodies (113) arranged along the height direction, wherein a through hole (111) of the tray body (113) located on the upper side and a through hole (111) of the tray body (113) located on the lower side are separated by the refractory plate (5).

5. The battery pack according to claim 4, wherein the refractory plate (5) is a mica plate.

6. Inside the housing (6), a side beam (7) and a plurality of first cross beams (4) are provided. The side beams (7) are combined to form a frame structure, and a third pressure relief passage (71) is provided inside the side beam (7). The plurality of first cross beams (4) are provided inside the frame structure and are connected to the side beam (7). The plurality of first cross beams (4) divide a plurality of regions inside the frame structure, and the battery modules are provided in each of the regions. The battery pack according to any one of claims 2 to 5.

7. The battery pack according to claim 6, wherein a second pressure relief passage (41) is provided in the first cross beam (4), and the first pressure relief passage (21), the pressure relief hole (112), the second pressure relief passage (41), and the third pressure relief passage (71) are in communication with each other.

8. The pair of support trays (11) arranged along the height direction are symmetrically arranged, and a plurality of the pressure relief holes (112) are provided in the tray extension portion (114) located on the lower side. The pressure relief hole (112), the second pressure relief passage (41), and the third pressure relief passage (71) are in communication with each other. The battery pack according to claim 7.

9. The battery pack according to claim 6, wherein an explosion-proof valve (72) is provided in the side beam (7), and the explosion-proof valve (72) is in communication with the third pressure relief passage (71).

10. The battery pack according to claim 4 or 5, wherein the module bracket (2) and a pair of the tray extension portions (114) arranged along the height direction are connected by a locking portion (8) to clamp the refractory plate (5).

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