Battery pack

Abstract

The utility model relates to battery structure technical field discloses a kind of battery pack, battery pack includes: battery cell unit, multiple are arranged at intervals along first direction;First fireproof plate, be located between adjacent battery cell unit, and the opposite side of battery cell unit along first direction is equipped with first fireproof plate;Second fireproof plate, and first fireproof plate located at the opposite side of battery cell unit is connected respectively;Second fireproof plate and the first end of the battery cell unit along third direction are oppositely arranged, and second fireproof plate is formed with weak area;Glue filling structure, at least with the second end of battery cell unit along third direction is connected arrangement;Battery pack provided by the utility model, when high temperature and high pressure gas is generated when battery cell thermal runaway, gas is limited by glue filling structure, directional impact second fireproof plate, and the plate body fracture at weak area of second fireproof plate, and outlet is formed along the scratch tear, directional pressure relief exhaust structure is formed, avoid gas irregularly scattered and spray.

Description

Technical Field

[0001] This utility model relates to the field of battery structure technology, specifically to a battery pack. Background Technology

[0002] As the main power source for electric bicycles, lithium-ion batteries are increasingly favored by the market due to their safety, reliability, and high energy density.

[0003] With the introduction of relevant national standards such as the "Safety Technical Specifications for Lithium-ion Batteries for Electric Bicycles", how to reduce the harm caused by thermal runaway after the occurrence of thermal runaway of lithium-ion batteries has become an urgent problem for manufacturers to solve.

[0004] In related technologies, under extreme conditions such as thermal runaway, pouch batteries generate high-temperature and high-pressure gases inside. These gases accumulate instantly and are often ejected randomly, which can cause a chain reaction of thermal runaway in adjacent batteries, or even cause the casing to burst, leading to safety accidents. Utility Model Content

[0005] In view of this, the present invention provides a battery pack to solve the problem that the gas generated during thermal runaway of pouch batteries often sprays out irregularly, causing safety accidents.

[0006] This utility model provides a battery pack, including: a battery module, the battery module including: a battery cell unit, the battery cell unit being arranged at intervals along a first direction; a first fireproof plate, disposed between adjacent battery cell units, the first fireproof plate being disposed on both opposite sides of the battery cell unit along the first direction; a second fireproof plate, respectively connected to the first fireproof plate located on opposite sides of the battery cell unit, the second fireproof plate being disposed opposite to a first end of the battery cell unit along a third direction, the second fireproof plate forming a weak area; and an encapsulation structure, at least connected to a second end of the battery cell unit along a third direction.

[0007] Beneficial effects: By pre-setting weak areas with lower strength in the second fireproof board, and arranging these weak areas to form grooves, when the battery cell experiences thermal runaway and generates high-temperature, high-pressure gas, the gas is restricted by the potting structure and impacts the second fireproof board in a directional manner. The board at the weak area of ​​the second fireproof board breaks and tears along the weak area to form an outlet, creating a directional pressure relief and exhaust structure, effectively preventing the gas from spraying out randomly. In addition, the second fireproof board at the normal battery cell unit remains intact, preventing gas from corroding the normal battery cell and avoiding chain thermal runaway between battery cells, thus significantly reducing the risk of safety accidents caused by thermal runaway.

[0008] In one alternative embodiment, the battery cell includes a body and a sealing edge connected together; the second fireproof plate is located on the side of the sealing edge away from the body.

[0009] In one optional embodiment, the groove includes a first groove and a second groove; the first groove extends along a first direction and is provided with at least two grooves spaced apart along a second direction; the second groove extends along a second direction; wherein the first groove connects at least two second grooves located on the same side at a first end, and a connecting section is formed between the at least two second grooves located on the same side at a second end.

[0010] Beneficial effects: By setting segmented grooves, the tearing direction can be guided. When the second fireproof board is impacted by gas, the second fireproof board is torn along the second groove and the first groove. Since the first groove extends along the first direction and the second groove extends along the second direction, the outlet has a certain length and width, ensuring smooth gas discharge. Since at least two second grooves are located on the same side between the second ends to form a connecting section, the torn board segment is still connected to the second fireproof board by means of the connecting section, preventing the torn board segment from falling off and moving to the exhaust port of the outer shell under the drive of the exhaust airflow, thus blocking the exhaust port.

[0011] In one optional embodiment, the second fireproof plate includes a main board and two wing plates; the two wing plates are respectively connected to a first fireproof plate located on opposite sides of the battery cell unit, and the main board is connected to at least two wing plates; the weak area is located at the main board.

[0012] Beneficial effects: The two ends of the wing plate are connected to the main board and the second fireproof plate respectively, so that the main board is supported by the wing plate at a certain distance, preventing interference between the main board and the components at the cell unit. In addition, when the cell unit generates high temperature and high pressure gas due to thermal runaway, the wing plate can provide a certain buffer distance in the third direction, avoiding the instantaneous high pressure from causing the main board to be overloaded, which could damage the main board or even cause it to detach from the battery module. Driven by the exhaust airflow, the main board moves to the exhaust port at the outer casing, causing blockage of the exhaust port.

[0013] In one optional embodiment, at least two first fireproof plates are provided between adjacent battery cells, and the battery module further includes a protective layer disposed between the at least two first fireproof plates.

[0014] Beneficial effects: By setting at least two first fireproof plates between adjacent battery cells and setting a protective layer between adjacent first fireproof plates, a multi-layer combined protective structure is formed, which can effectively prevent the spread of high temperature and flame generated when a battery cell runs away from thermally between adjacent battery cells and prevent chain thermal runaway.

[0015] In one alternative embodiment, the battery pack further includes a housing that covers the outside of the battery module, and the housing has an exhaust port on one side along a first direction.

[0016] Beneficial effects: The exhaust port is located on one side of the outer casing along the first direction, and the battery cells inside the casing are arranged sequentially along the first direction. When a battery cell experiences thermal runaway, the generated gas breaks through the weak area of ​​the second fireproof plate and flows along the first direction to the exhaust port, forming a straight exhaust path with high exhaust efficiency.

[0017] In one alternative implementation, at least one of the second notches is located on one side edge of the motherboard near the vent; and / or at least two of the first notches are located on opposite sides of the motherboard along a second direction.

[0018] Beneficial effects: The second notch is set on the edge of the motherboard near the exhaust port, and at least two first notches are set on the opposite sides of the motherboard along the second direction. The connecting section is set on the edge of the motherboard away from the exhaust port, so that the torn section of the motherboard flips open to the side away from the exhaust port, without interfering with or blocking the exhaust airflow. The exhaust airflow is discharged in the direction closer to the exhaust port, ensuring smooth exhaust.

[0019] In one optional embodiment, the outer casing includes a housing and a cover. The housing has an opening at one end along a first direction, and the cover is connected to the housing and covers the opening. A portion of the housing located on the side of the main board away from the battery cell unit protrudes in a direction away from the main board to form a first exhaust channel. An exhaust port is opened in the cover, and a second exhaust channel is formed around the exhaust port inside the cover. The second exhaust channel communicates with the first exhaust channel. The inner wall of the second exhaust channel is covered with a fireproof layer.

[0020] Beneficial effects: The gas generated after thermal runaway of the battery cell flows to the exhaust port through the first exhaust channel and is discharged; the second exhaust channel is set in the cover body and is set in the first direction corresponding to the first exhaust channel. The first exhaust channel and the second exhaust channel play the role of guiding the gas to the exhaust port. The first exhaust channel and the second exhaust channel cooperate to form a straight exhaust path, which improves exhaust efficiency.

[0021] In one optional embodiment, the potting structure includes a first potting compound layer disposed between the outer casing and the battery cell, and sealing the second end of the battery cell; the potting structure further includes a second potting compound layer disposed between the outer casing and the battery cell on opposite sides along a second direction.

[0022] Beneficial effects: The battery module is equipped with a potting structure at the end away from the second fireproof plate, at both ends of the cell unit along the second direction, and on the side of the circuit board away from the cell unit. When the cell experiences thermal runaway and generates high-temperature and high-pressure gas, the gas is restricted by the potting structure (only the side where the second fireproof plate is located is not sealed with potting). The gas impacts the second fireproof plate in a directional manner, breaks through the weak area, and is discharged. At the same time, the potting structure can also effectively resist external impacts, absorb vibration energy, prevent the battery module from shaking inside the casing, and improve structural stability.

[0023] In one optional embodiment, the battery cell unit further includes a circuit board disposed on the side of the sealing edge away from the main body, and the circuit board is disposed on both sides of the second fireproof board along the second direction. The battery cell unit further includes a tab extending from the sealing edge, and the tab is electrically connected to the circuit board. A third potting compound layer is provided on the side of the circuit board away from the battery cell unit. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the battery cell unit of this utility model;

[0026] Figure 2 This is a schematic diagram showing the cooperation between the first fireproof board and the second fireproof board of this utility model;

[0027] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0028] Figure 4 This is a top view of the second fireproof board of this utility model;

[0029] Figure 5 This is a schematic diagram showing the combination of the first fireproof board, the second fireproof board, and the battery cell unit of this utility model;

[0030] Figure 6 for Figure 5 Enlarged view of point B in the middle;

[0031] Figure 7 This is a schematic diagram of the battery module of this utility model;

[0032] Figure 8 This is a schematic diagram of the potting compound layer of this utility model;

[0033] Figure 9 This is a schematic diagram of the battery pack of this utility model;

[0034] Figure 10 This is a schematic diagram of the cover of this utility model.

[0035] Explanation of reference numerals in the attached figures:

[0036] 1. Battery module; 11. Circuit board; 12. Electrical connectors;

[0037] 2. Battery cell unit; 21. Main body; 22. Edge sealing;

[0038] 3. First fireproof board; 31. Protective layer; 311. Flame retardant layer; 312. Heat insulation layer;

[0039] 4. Second fireproof board; 41. Main board; 42. Wing plate;

[0040] 5. Polar ears;

[0041] 6. Weak area; 61. First notch; 62. Second notch; 63. Continuous material section;

[0042] 7. Outer shell; 71. Fireproof layer; 72. Second exhaust channel; 73. Exhaust port; 74. First exhaust channel; 75. Cover; 76. Shell; 77. Explosion-proof valve;

[0043] 8. Potting structure; 81. First potting compound layer; 82. Second potting compound layer;

[0044] 9. Third potting compound layer. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0046] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model 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, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0047] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0048] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0049] The following is combined with Figures 1 to 10 The following describes embodiments of the present invention.

[0050] According to an embodiment of the present invention, a battery pack is provided, comprising: a battery module 1, the battery module 1 comprising: a battery cell unit 2, wherein a plurality of battery cell units 2 are spaced apart along a first direction; a first fireproof plate 3 disposed between adjacent battery cell units 2, wherein the first fireproof plate 3 is disposed on both opposite sides of the battery cell unit 2 along the first direction; a second fireproof plate 4 respectively connected to the first fireproof plate 3 located on opposite sides of the battery cell unit 2, wherein the second fireproof plate 4 is disposed opposite to a first end of the battery cell unit 2 along a third direction, and the second fireproof plate 4 forms a weak area 6; and an encapsulation structure 8, which is at least connected to a second end of the battery cell unit 2 along a third direction.

[0051] It should be noted that the strength of the weak area 6 on the second fireproof board 4 is lower than the strength of the other parts of the second fireproof board 4. After the battery cell undergoes thermal runaway, it generates high-temperature and high-pressure gas. Since the potting structure 8 is connected to the second end of the battery cell unit 2 along the third direction, the gas is restricted and impacts the second fireproof board 4. The board at the weak area 6 on the second fireproof board 4 breaks, and the second fireproof board 4 tears along the weak area 6 to form an outlet. The gas is discharged directionally from the outlet, thus playing the role of directional exhaust.

[0052] In this embodiment, by pre-setting a weak area 6 with lower strength at the second fireproof plate 4, when the battery cell generates high-temperature and high-pressure gas due to thermal runaway, the gas is restricted by the potting structure 8 and impacts the second fireproof plate 4 in a directional manner. The plate body at the weak area 6 on the second fireproof plate 4 breaks and tears along the weak area 6 to form an outlet, forming a directional pressure relief and exhaust structure, which effectively prevents the gas from spraying out randomly. In addition, the second fireproof plate 4 at the normal battery cell unit 2 remains intact, preventing the gas from corroding the normal battery cell and avoiding the chain thermal runaway between battery cells, which greatly reduces the risk of safety accidents caused by thermal runaway.

[0053] It should be noted that the weak area 6 can be, but is not limited to, formed by pits. The pits are recessed and formed at the second fireproof board 4 to weaken the strength of the board at that point. Multiple pits are arranged in sequence to form grooves.

[0054] In some embodiments, the battery cell 2 includes a main body 21 and a sealing edge 22 connected together; the second fireproof plate 4 is located on the side of the sealing edge 22 away from the main body 21.

[0055] Specifically, the main function of the edge seal 22 is to release gas when the internal pressure of the battery is too high, so as to prevent the battery from exploding or catching fire due to excessive pressure. Furthermore, the second fireproof plate 4 is set on the side of the edge seal 22 away from the main body 21. When the cell unit 2 is thermally runaway, the second fireproof plate 4 is directly impacted by the gas, and then tears and vents along the weak area 6.

[0056] In some embodiments, the weak area 6 includes a first notch 61 and a second notch 62; the first notch 61 extends along a first direction and is provided with at least two notches spaced apart along a second direction; the second notches 62 extend along a second direction; wherein the first notch 61 connects at least two second notches 62 located at the first end on the same side, and a connecting section 63 is formed between the at least two second notches 62 located at the second end on the same side.

[0057] It should be noted that at least one weak area 6 at the end of the first notch 61 is aligned with at least one weak area 6 at the second notch 62 so that the first notch 61 and the second notch 62 are connected.

[0058] Specifically, by setting segmented weak zones 6, the tearing direction can be guided. When the second fireproof board 4 is impacted by gas, the second fireproof board 4 is torn along the second notch 62 and the first notch 61. Since the first notch 61 extends along the first direction and the second notch 62 extends along the second direction, the outlet has a certain length and width to ensure smooth gas discharge. Since at least two second notches 62 are located on the same side between the second ends to form a connecting section 63, the torn board segment and the second fireproof board 4 are still connected by the connecting section 63, preventing the torn board segment from falling off and moving to the exhaust port 73 at the outer shell 7 under the drive of the exhaust airflow, thus blocking the exhaust port 73.

[0059] In some embodiments, the second fireproof plate 4 includes a main plate 41 and two wing plates 42; the two wing plates 42 are respectively connected to the first fireproof plate 3 located on opposite sides of the battery cell unit 2, and the main plate 41 is connected to the two wing plates 42; the weak area 6 is located at the main plate 41.

[0060] Specifically, the main board 41 and the wing plate 42 can be, but are not limited to, vertically connected; the two ends of the wing plate 42 are respectively connected to the main board 41 and the second fireproof plate 4, so that the main board 41 is supported by the wing plate 42 at a certain distance, preventing the main board 41 from interfering with the components at the battery cell unit 2. When the battery cell unit 2 thermally runs away and generates high temperature and high pressure gas, the wing plate 42 can provide a certain buffer distance in the third direction, avoiding the instantaneous high pressure from causing the main board 41 to be subjected to overload pressure, causing the main board 41 to be damaged as a whole or even detached from the battery module 1. Driven by the exhaust airflow, it moves to the exhaust port 73 at the outer casing 7, causing the exhaust port 73 to be blocked.

[0061] In some embodiments, at least two first fireproof plates 3 are provided between adjacent battery cell units 2, and the battery module 1 further includes a protective layer 31, which is disposed between two adjacent first fireproof plates 3.

[0062] Specifically, the materials of the first fireproof board 3 and the second fireproof board 4 can be, but are not limited to, mica boards. Mica boards are made of multiple layers of stacked mica sheets, which have good mechanical strength and insulation properties. Mica sheets are made of thick mica sheets and have fire resistance and insulation properties. They can maintain structural stability at high temperatures, do not burn, and do not conduct electricity, making them good electrical and thermal insulation materials.

[0063] Specifically, the protective layer 31 includes a stacked flame-retardant layer 311 and a heat insulation layer 312. The heat insulation layer 312 can be aerogel felt, which is a heat insulation material made of aerogel as the main material 21, combined with carbon fiber, ceramic glass fiber cotton, or pre-oxidized fiber felt through a special process. It has low thermal conductivity and light weight. It has fire resistance and extremely low thermal conductivity, and is mainly composed of a gel matrix, composite layer, and adhesive. It can be replaced by other materials for heat insulation and fire protection of battery cells. The flame-retardant layer 311 can be ceramicized silica foam, which is a functional foam material made of silicone rubber as the base material, with the addition of ceramic fillers and a foaming process. It has the soft elasticity of silicone materials and the high temperature resistance and fire resistance of ceramics.

[0064] In this embodiment, by setting at least two first fireproof plates 3 between adjacent battery cell units 2 and setting a protective layer 31 between adjacent first fireproof plates 3, a multi-layer combined protective structure is formed, which can effectively block the spread of high temperature and flame generated when a certain battery cell unit 2 thermally runs away between adjacent battery cell units 2, and prevent chain thermal runaway.

[0065] Optionally, the protective layer 31 and the fireproof layer 71 are bonded together with adhesive; wherein, the flame retardant layer 311 and the heat insulation layer 312 are bonded together with adhesive, and the flame retardant layer 311 covers the side of the heat insulation layer 312 near the exhaust port 73.

[0066] In some embodiments, the battery pack further includes a housing 7, which covers the outside of the battery module 1, and the housing 7 has an exhaust port 73 on one side along a first direction.

[0067] Specifically, the exhaust port 73 is located on one side of the outer casing 7 along the first direction and is close to the second fireproof plate 4; an explosion-proof valve 77 is provided at the exhaust port 73. The explosion-proof valve 77 is a safety valve with a pressure-sensitive triggering mechanism. It is installed at the exhaust port 73 of the battery pack outer casing 7 and is used to automatically open when the internal gas pressure exceeds the safety threshold, quickly release high-temperature and high-pressure gas, and prevent the outer casing 7 from exploding; after the pressure drops, it can reset the seal to prevent external contaminants from entering.

[0068] In this embodiment, the exhaust port 73 is located on one side of the outer casing 7 along the first direction, and the battery cell units 2 inside the outer casing 7 are arranged sequentially along the first direction. When a battery cell unit 2 experiences thermal runaway, the generated gas breaks through the weak area 6 of the second fireproof plate 4 and flows along the first direction to the exhaust port 73, forming a straight exhaust path with high exhaust efficiency.

[0069] In some embodiments, at least one second notch 62 is located on one side edge of the motherboard 41 near the vent 73; at least two first notches 61 are located on opposite sides of the motherboard 41 along a second direction.

[0070] Specifically, the second notch 62 is set on the edge of the main board 41 near the exhaust port 73, and at least two first notches 61 are set on the opposite sides of the main board 41 along the second direction. The connecting section 63 is set on the edge of the main board 41 away from the exhaust port 73, so that the torn section of the main board 41 flips open to the side away from the exhaust port 73, without interfering with or blocking the exhaust airflow. The exhaust airflow is discharged in the direction close to the exhaust port 73, ensuring smooth exhaust.

[0071] In some embodiments, the outer casing 7 includes a housing 76 and a cover 75. The housing 76 has an opening at one end along a first direction, and the cover 75 is connected to the housing 76 and covers the opening. The portion of the housing 76 located on the side of the main board 41 away from the battery cell unit 2 protrudes in a direction away from the main board 41 to form a first exhaust channel 74. An exhaust port 73 is opened in the cover 75, and a second exhaust channel 72 is formed around the exhaust port 73 inside the cover 75. The second exhaust channel 72 communicates with the first exhaust channel 74. The inner wall of the second exhaust channel 72 is covered with a fireproof layer 71.

[0072] Specifically, the gas generated after thermal runaway of the battery cell 2 flows through the first exhaust channel 74 to the exhaust port 73 for discharge; the second exhaust channel 72 is set inside the cover 75 and is set in the first direction corresponding to the first exhaust channel 74. The first exhaust channel 74 and the second exhaust channel 72 guide the gas to flow to the exhaust port 73. The first exhaust channel 74 and the second exhaust channel 72 cooperate to form a straight exhaust path, thereby improving exhaust efficiency.

[0073] Specifically, the fireproof layer 71 can be, but is not limited to, mica paper. Mica paper is an industrial paper made primarily of mica, which has insulation and high-temperature resistance properties. By setting the fireproof layer 71 on the inner wall of the second exhaust channel 72, the fireproof layer 71 can block high temperatures during exhaust, prevent the cover 75 from melting due to high temperatures, and reduce the heat radiation effect on the second exhaust channel 72.

[0074] In some embodiments, the potting structure 8 includes a first potting compound layer 81 disposed between the housing 7 and the battery cell 2, and sealing the second end of the battery cell 2; the potting structure 8 also includes a second potting compound layer 82 disposed between the housing 7 and the opposite sides of the battery cell 2 along a second direction.

[0075] In some embodiments, the battery cell unit 2 further includes a circuit board 11 disposed on the side of the sealing edge 22 away from the main body 21, and the circuit board 11 is disposed on both sides of the second fireproof board 4 along the second direction. The battery cell unit 2 further includes a tab 5 extending from the sealing edge 22, and the tab 5 is electrically connected to the circuit board 11. A third potting compound layer 9 is provided on the side of the circuit board 11 away from the battery cell unit 2.

[0076] Specifically, the battery module 1 also includes an electrical connector 12, the first end of which is connected to the tab 5, and the second end of which is electrically connected to the circuit board 11; wherein, the second end of the electrical connector 12 passes through the circuit board 11 and bends, and extends on the side of the circuit board 11 away from the cell unit 2; the two circuit boards 11 are located on opposite sides of the second fireproof plate 4 along the second direction, and the circuit boards 11 do not interfere with the second fireproof plate 4.

[0077] Specifically, the end of the battery module 1 away from the second fireproof plate 4, the two opposite ends of the cell unit 2 along the second direction, and the side of the circuit board 11 away from the cell unit 2 are all provided with potting structures 8. Thus, when the cell thermally runs away and generates high-temperature and high-pressure gas, the gas is restricted by the potting structure 8 (only the side where the second fireproof plate 4 is located is not sealed with potting). The gas impacts the second fireproof plate 4 in a directional manner, breaks through the weak area 6, and is discharged. At the same time, the potting structure 8 can also effectively resist external impacts, absorb vibration energy, prevent the battery module 1 from shaking inside the outer casing 7, and improve structural stability.

[0078] When the battery pack is working, if a certain cell unit 2 experiences thermal runaway, the cell unit 2 will generate high-temperature and high-pressure gas. The gas impacts the second fireproof plate 4, and the plate at the weak area 6 is torn. The second fireproof plate 4 is torn along the weak area 6, forming an outlet at the torn position. Because the weak area 6 is segmented and located at the edge of the main board 41, the outlet is relatively large. The gas flows smoothly out of the outlet into the first exhaust channel 74 and is discharged towards the exhaust port 73 and the explosion-proof valve 77. When the gas reaches the opening pressure of the explosion-proof valve 77, the explosion-proof valve 77 opens, and the gas is quickly discharged outward. The entire exhaust process is rapid and smooth, and does not affect other cell units 2 in normal condition. The gas is discharged and depressurized in a directional manner, effectively avoiding chain thermal runaway.

[0079] Obviously, the above embodiments are merely examples for clear illustration and are not intended to limit the implementation. Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and all such modifications and variations fall within the scope defined by the present invention.

Claims

1. A battery pack, characterized in that, include: Battery module (1), the battery module (1) comprising: A battery cell unit (2), wherein multiple battery cell units (2) are spaced apart along a first direction; A first fireproof plate (3) is provided between adjacent battery cell units (2), and the first fireproof plate (3) is provided on both sides of the battery cell unit (2) along the first direction; The second fireproof plate (4) is connected to the first fireproof plate (3) located on opposite sides of the battery cell unit (2). The second fireproof plate (4) is arranged opposite to the first end of the battery cell unit (2) in a third direction. The second fireproof plate (4) has a weak area (6). The potting structure (8) is connected to at least the second end of the battery cell unit (2) in a third direction.

2. The battery pack according to claim 1, characterized in that, The weak area (6) includes a first notch (61) and a second notch (62); The first groove (61) extends along a first direction and is provided with at least two grooves at intervals along a second direction; The second notch (62) extends along the second direction; The second groove (62) connects at least two first grooves (61) located on the same side of the first end, and at least two first grooves (61) located on the other side of the second end to form a connecting section (63).

3. The battery pack according to claim 2, characterized in that, The second fireproof board (4) includes a main board (41) and two wing plates (42); Two wing plates (42) are respectively connected to the first fireproof plate (3) located on opposite sides of the battery cell unit (2), and the main board (41) is connected to the two wing plates (42); The weak area (6) is located at the main board (41).

4. The battery pack according to claim 3, characterized in that, At least two first fireproof plates (3) are provided between adjacent battery cell units (2), and the battery module (1) also includes a protective layer (31) between two adjacent first fireproof plates (3).

5. The battery pack according to claim 3, characterized in that, The battery pack also includes a housing (7) which covers the outside of the battery module (1) and has an exhaust port (73) on one side along a first direction.

6. The battery pack according to claim 5, characterized in that, The second notch (62) is located on the edge of the motherboard (41) near the exhaust port (73); And / or, at least two of the first grooves (61) are located at opposite sides of the motherboard (41) along the second direction.

7. The battery pack according to claim 5, characterized in that, The outer casing (7) includes a shell (76) and a cover (75), wherein the shell (76) is open at one end along a first direction, and the cover (75) is connected to the shell (76) and covers the opening; The shell (76) is located on the side of the main board (41) away from the battery cell unit (2), and protrudes in a direction away from the main board (41) to form a first exhaust channel (74); The exhaust port (73) is opened in the cover (75), and a second exhaust channel (72) is formed around the exhaust port (73) inside the cover (75). The second exhaust channel (72) is connected to the first exhaust channel (74). The inner wall of the second exhaust channel (72) is covered with a fireproof layer (71).

8. The battery pack according to claim 5, characterized in that, The potting structure (8) includes a first potting compound layer (81), which is disposed between the outer shell (7) and the battery cell (2) and seals the second end of the battery cell (2); The potting structure (8) further includes a second potting layer (82), which is disposed between the outer shell (7) and the battery cell (2) on opposite sides along the second direction.

9. The battery pack according to claim 1, characterized in that, The battery cell unit (2) includes a main body (21) and a sealing edge (22) connected along a third direction; The second fireproof board (4) is located on the side of the edge seal (22) away from the main body (21).

10. The battery pack according to claim 9, characterized in that, The battery module (1) also includes a circuit board (11), which is located on the side of the sealing edge (22) away from the main body (21), and the second fireproof plate (4) is provided with the circuit board (11) on both sides along the second direction. The cell unit (2) also includes a tab (5) extending from the sealing edge (22), which is electrically connected to the circuit board (11). The circuit board (11) has a third potting compound layer (9) on the side opposite to the battery cell unit (2).

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