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 Chinese Patent Application No. 202211598515.7, filed with the Chinese Patent Office on December 14, 2022, the entire contents of which are 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, 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.

[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 flame are instantaneously released inside the cells. Since there is no directional exhaust passage to guide these gases 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, resulting in the spread of thermal runaway and being likely to lead to a fire or explosion, leaving 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 is A battery module comprising a pair of battery assemblies stacked and arranged along the height direction, Each battery assembly includes a support tray and a cell group, the support tray has multiple through holes extending along its height, multiple pressure relief valves for multiple single cells within the cell group are arranged one-to-one in the multiple through holes, a pair of pressure relief valves for cell groups arranged along the height direction are arranged opposite each other, and the support tray is further provided with multiple pressure relief holes, the battery module, A module bracket is provided between a pair of support trays arranged along the height direction and has a first pressure relief passage, wherein a pressure relief cavity is provided between the pair of support trays arranged along the height direction, and the through hole, the pressure relief cavity, the first pressure relief passage, and the pressure relief hole are in communication with each other. The present invention includes a housing in which a battery module is provided, a third pressure relief passage is provided in the housing, and the third pressure relief passage and the pressure relief hole are in communication with each other.

[0007] In one embodiment, each support tray includes a tray body with mounting grooves and a tray extension provided on the periphery of the tray body, and each tray body is provided with a plurality of through holes extending through it along its height direction. 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.

[0008] In one embodiment, both the tray extension and the module bracket are rectangular ring-shaped.

[0009] In one embodiment, The structure further includes a fire-resistant plate placed between a pair of tray bodies arranged along the height direction, with the through-holes of the upper tray body and the lower tray body separated by the fire-resistant plate.

[0010] In one embodiment, side beams and a plurality of first crossbeams are provided inside the housing, the side beams are combined to form a frame structure, and a third pressure relief passage is provided inside the side beams. Multiple first crossbeams are provided inside the frame structure and connected to the side beams, and the multiple first crossbeams divide the frame structure into multiple regions, each of which is provided with a battery module.

[0011] In one embodiment, the first crossbeam is provided with a second pressure relief passage, and the first pressure relief passage, the pressure relief hole, the second pressure relief passage, and the third pressure relief passage are in communication with each other.

[0012] In one embodiment, a pair of support trays arranged along the height direction are symmetrically positioned, and the lower tray extension is provided with a plurality of pressure relief holes, with the pressure relief holes, a second pressure relief passage, and a third pressure relief passage communicating with each other.

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

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

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

[0016] In actual applications, in the two-layer battery assembly of the battery pack according to the embodiment of this application, since the single cell of the battery assembly is a cylindrical cell and the pressure relief valve of the cylindrical cell is located at the bottom of the cell itself, the two-layer battery assembly has a mounting structure in which the bottoms of the single cells are arranged opposite each other. When the battery overheats and becomes uncontrollable, the generated gas and flame concentrate in a pressure relief cavity formed between a pair of support trays arranged vertically through through holes. The generated gas and flame then flow into a first pressure relief passage of the module bracket, further into the pressure relief holes of the support trays, and finally into a 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 this application are, in part, described below, and in part will become apparent from the following description or will be understood through the practice of this application. [Brief explanation of the drawing]

[0018] [Figure 1] This is a schematic diagram of the structure of the battery pack in the embodiment of this application. [Figure 2] This is a schematic diagram of the internal structure of the battery pack in the embodiment of this application. [Figure 3] This is a magnified view of part A in Figure 2. [Figure 4] This is another schematic diagram of the internal structure of the battery pack in the embodiment of this application. [Figure 5] This is a schematic diagram of the structure of the support tray in an embodiment of this application. [Figure 6] This is a schematic diagram of the structure of the module bracket in the embodiment of this application. [Figure 7] This is a schematic diagram showing the disassembled state of the battery pack in the embodiment of this application. [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", "outer", etc. 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 device or element 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 explaining specific embodiments and are not intended to limit this application.

[0021] Hereinafter, referring to FIGS. 1 to 6, the battery pack and the power consumption device according to the embodiments 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 requirements for vehicle weight reduction have 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 related two-layer module battery packs, sealing is difficult, making it challenging to design dedicated exhaust and pressure relief passages. As a result, two-layer module battery packs lack dedicated exhaust and pressure relief passages. Therefore, if thermal runaway occurs in a cell on the module, a large amount of gas and associated flames are instantly released into the cell. Without directional exhaust passages to guide these gases and flames, they spread randomly within the battery pack, easily igniting other components. This can cause thermal runaway in other cells that are operating normally, leading to the spread of thermal runaway and increasing the risk of fire or explosion. There is room for improvement.

[0024] In view of the above, the battery pack in the embodiment of this application is provided with a dedicated exhaust and pressure relief structure in the two-layer module that guides these gases and flames in a specific direction in the event of thermal runaway and prevents the spread of thermal runaway.

[0025] Specifically, please refer to Figures 1 to 6. The battery pack in the embodiment of this 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 stacked vertically along the height direction, each of which includes a support tray 11 and a cell group 12. The support tray 11 has a plurality of through holes 111 extending through it along its height direction, and pressure relief valves for a plurality of single cells within the cell group 12 are arranged in a one-to-one correspondence with the plurality of through holes 111. The pressure relief valves for a pair of cell groups 12 arranged along the height direction are arranged opposite each other, and the support tray 11 is further provided with a plurality of pressure relief holes 112. The module bracket 2 is positioned between the 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 the 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 with each other. The battery module is housed inside the housing 6, and the housing 6 is provided with a third pressure relief passage 71, which is connected to the pressure relief hole 112.

[0027] In actual applications, in the two-layer battery assembly 1 of the battery pack in the embodiment of this application, the single cell of the battery assembly 1 is a cylindrical cell, and the pressure relief valve of the cylindrical cell is located at the bottom of the cell itself, so the two-layer battery assembly 1 has a mounting structure in which the bottoms of the single cells are arranged facing each other. When the battery overheats and becomes uncontrollable, the generated gas and flame concentrate in the pressure relief cavity 3 formed between a pair of support trays 11 arranged vertically through the through hole 111. Next, the generated gas and flame 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 gases and flames are guided through the third pressure relief passage 71, 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 fire or explosion.

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

[0029] Specifically, please refer to Figures 1 to 6. In the battery pack according to the embodiment of this application, each support tray 11 includes a tray body 113 having a mounting groove formed therein and a tray extension 114 provided on the periphery of the tray body 113. Each tray body 113 is provided with a plurality of through holes 111 running through it along its height direction, and 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, the battery module of the battery pack in the embodiment of this application is provided with a pair of support trays 11, and since the support trays 11 include a tray body 113 with mounting grooves formed therein, the tray body 113 itself has a certain height, thereby creating a mounting gap between the pair of tray extensions 114 for attaching the module bracket 2. Therefore, the cell group 12 is mounted corresponding to the mounting grooves of the tray body 113, the module bracket 2 is mounted corresponding to the tray extensions 114, and the cell group 12 is provided correspondingly within the module bracket 2. Consequently, the heights of the cell group 12 and the module bracket 2 partially overlap, making the structure more compact, which in turn reduces the thickness of the battery pack to some extent, achieving miniaturization and weight reduction.

[0031] As can be seen from the above, when the battery overheats and becomes uncontrollable, the generated gas and flame concentrate in the pressure relief cavity 3, then flow toward the edge of the support tray 11, into the first pressure relief passage 21 of the module bracket 2, further into the pressure relief hole 112 of the support tray 11, and finally 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 within the battery pack, effectively preventing the spread of thermal runaway, and preventing more serious fires or explosions.

[0032] Existing battery packs are typically made in a square case shape, and in order to fit this square case shape, the battery pack, tray extension 114, and module bracket 2 in the embodiment of the present invention are all rectangular ring-shaped.

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

[0034] In further applications, it was discovered that, due to the two-layer module configuration of this battery pack, if a single cell in one of the cell groups 12 layers experiences thermal runaway, the generated gas and flames are ejected towards the bottom of a single cell in the opposing cell group 12, causing further thermal runaway. Therefore, to prevent the generated gas and flames from being ejected to the bottom of a single cell in the opposing module and causing thermal runaway, this battery pack is provided with a fire-resistant plate 5 that prevents the diffusion of thermal runaway between the two-layer modules by blocking it.

[0035] Specifically, please refer to Figures 1 to 6. The battery pack in the embodiment of this application further includes a fireproof plate 5, which is positioned between a pair of tray bodies 113 arranged in the height direction, and 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 fireproof plate 5.

[0036] In actual applications, if a single cell in a single-layer cell group 12 of the battery pack in the embodiment of this application experiences thermal runaway, the generated gas and flame will be ejected towards the fireproof plate 5, flow along the fireproof plate 5 toward 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 hole 112 of the support tray 11, and finally flow 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 within the battery pack, effectively preventing the spread of thermal runaway, and preventing more serious fires or explosions. Furthermore, it effectively prevents the generated gases and flames from being ejected to the bottom of a single cell in an opposing module, causing thermal runaway, and prevents the spread of thermal runaway between two-layer modules.

[0037] The fire-resistant board 5 may be a high-temperature resistant mica board, for example, one that can be made by bonding, heating, and pressurizing mica board, mica paper, and organic silicone adhesive, with a mica content of approximately 90% and an organic silicone adhesive content of 10%.

[0038] Further applications have shown that to increase the battery capacity of a battery pack, it is common to include multiple battery modules within the battery pack. In order to allow the multiple battery modules to efficiently dissipate the gas and flame generated when thermal runaway occurs, the structure of the housing 6 in this battery pack has been improved.

[0039] Specifically, please refer to Figures 1 to 6. In the battery pack according to the embodiment of this application, side beams 7 and a plurality of first crossbeams 4 are provided inside the housing 6, the side beams 7 are combined to form a frame structure, a third pressure relief passage 71 is provided inside the side beams 7, the plurality of first crossbeams 4 are provided inside the frame structure and connected to the side beams 7, the plurality of first crossbeams 4 divide the frame structure into a plurality of regions, and a battery module is provided in each region.

[0040] In other embodiments, the first crossbeam 4 is provided with a second pressure relief passage 41, 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.

[0041] In actual applications, the multiple battery modules and multiple first crossbeams 4 of the battery pack in the embodiment of this application are arranged alternately with spacing between them, so that one battery module is positioned between two first crossbeams 4. When the battery overheats and becomes uncontrollable, the generated gas and flame concentrate in the pressure relief cavity 3 formed between a pair of support trays 11 arranged vertically through the through-holes 111. The generated gas and flame then flow into the first pressure relief passage 21 of the module bracket 2, then into the pressure relief holes 112 of the support tray 11, then first into the second pressure relief passage 41 of the first crossbeams 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 within the battery pack, effectively preventing the spread of thermal runaway, and preventing more serious fires or explosions.

[0042] Furthermore, from a positional standpoint, the gas and flame generated by the battery module flow to the first crossbeams 4 on both sides, and are then guided through the second pressure relief passages 41, 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.

[0043] The structure for guiding the flow of the generated gas and flame can be specifically seen in Figures 1 to 6. The side beam 7 is provided with an exhaust port, which communicates with the outside of the housing and a third pressure relief passage 71. The exhaust port is sealed by an explosion-proof valve 72, which communicates with the third pressure relief passage 71. The side beam 7 may specifically be concave in shape.

[0044] In actual applications, if thermal runaway occurs in the battery module, the generated gas and flames flow into the second pressure relief passage 41 in the first crossbeam 4, then into the third pressure relief passage 71 in the side beam 7, and finally into the explosion-proof valve 72, which automatically opens to release the pressure and prevent the battery pack 100 from exploding.

[0045] In a further application, a fireproof plate 5 is provided between a pair of tray bodies 113 arranged along the height direction. When thermal runaway occurs, the generated gas and flames are ejected towards the fireproof plate 5. Therefore, it was found that the fireproof plate 5 needs to be fixed in place to prevent uneven ejection during thermal runaway. This battery pack fastens and fixes the fireproof plate 5 using a clamping structure.

[0046] Specifically, please refer to Figures 1 to 6. In the battery pack of the embodiment of this application, the module bracket 2 and a pair of tray extensions 114 arranged along the height direction are connected by a locking portion 8 to fasten the fireproof plate 5.

[0047] In actual applications, the battery pack secures a pair of tray extensions 114 to the module bracket 2 via locking parts 8, and further fastens the fireproof plate 5 via a pair of tray bodies 113, thereby securing the fireproof plate 5 and preventing uneven ejection during thermal runaway. Here, the locking parts 8 may specifically be bolts or screws.

[0048] The embodiments of this application disclose not only battery packs but also power consumption devices including battery packs. Power consumption devices may include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric bicycles, electric vehicles, ships, and spacecraft. Electric toys may include stationary or mobile electric toys such as game consoles, electric vehicle toys, electric boat toys, and electric airplane toys, and spacecraft may include airplanes, rockets, space shuttles, and spacecraft. Power tools include power tools for metal cutting, power tools for polishing, power tools for assembly, and power tools for railways, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drills, concrete vibrators, and electric planers. [Explanation of Symbols]

[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 part

Claims

1. It is a battery pack, A battery module comprising a pair of battery assemblies (1) arranged in a stack along the height direction, Each of the battery assemblies (1) includes a support tray (11) and a cell group (12), each of the support trays (11) includes a tray body (113) having mounting grooves and a tray extension (114) provided on the periphery of the tray body (113), the tray body (113) of the support tray (11) has a plurality of through holes (111) extending through it in the height direction, pressure relief valves for a plurality of single cells in the cell group (12) are arranged one-to-one in the plurality of through holes (111), a pair of pressure relief valves for the cell group (12) arranged in the height direction are arranged opposite each other, the pair of support trays (11) arranged in the height direction are arranged symmetrically, and the tray extension (114) of the lower support tray (11) is further provided with a plurality of pressure relief holes (112), and A module bracket (2) is positioned between a pair of support trays (11) arranged along the height direction and is provided with a first pressure relief passage (21), wherein a pressure relief cavity (3) is provided between the pair of support trays (11) arranged along the height direction, and the through hole (111), the pressure relief cavity (3), the first pressure relief passage (21), and the pressure relief hole (112) are in communication with each other. A battery pack comprising a housing (6), wherein the battery module is provided inside the housing (6), the housing (6) is provided with a third pressure relief passage (71), and the third pressure relief passage (71) and the pressure relief hole (112) are in communication with each other.

2. The battery pack according to claim 1, wherein the pressure relief cavity (3) is provided between a pair of tray bodies (113) arranged along the height direction, and the module bracket (2) is provided between a pair of tray extensions (114) arranged along the height direction.

3. The battery pack according to claim 2, wherein both the tray extension portion (114) and the module bracket (2) are rectangular ring-shaped.

4. The battery pack according to claim 2, further comprising a fireproof plate (5) provided between a pair of tray bodies (113) arranged along the height direction, wherein 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 fireproof plate (5).

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

6. The housing (6) is provided with side beams (7) and a plurality of first crossbeams (4), the side beams (7) are combined to form a frame structure, and the third pressure relief passage (71) is provided within the side beams (7). The battery pack according to any one of claims 2 to 5, wherein the plurality of first crossbeams (4) are provided inside the frame structure and connected to the side beams (7), and the plurality of first crossbeams (4) divide the frame structure into a plurality of regions, each of which is provided with the battery module.

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

9. The battery pack according to claim 6, wherein the side beam (7) is provided with an explosion-proof valve (72), 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 tray extensions (114) arranged along the height direction are connected by a locking portion (8) to tighten the fireproof plate (5).

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