Pressure relief assembly and battery pack

Abstract

The utility model discloses a pressure relief assembly and a battery pack. The pressure relief assembly comprises a valve body; the air inlet channel is formed in the air inlet side of the valve body; the exhaust channel is obliquely arranged between the air inlet channel and the exhaust side of the valve body, the exhaust side of the valve body is communicated with an exhaust port of the exhaust channel, and an air inlet of the exhaust channel is communicated with an exhaust port of the air inlet channel; and the triggering piece is sealed in the air inlet channel. According to the pressure relief valve, the exhaust channel is obliquely arranged between the air inlet channel and the exhaust side of the valve body, so that the pressure relief assembly can be effectively prevented from being opened due to external ball hit or foreign matters.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a pressure relief component and a battery pack. Background Art

[0002] In the prior art, when the battery cells in the battery pack are in thermal runaway, they will generate a large amount of heat and gas, and will emit high-temperature and high-pressure eruptions to the outside, and then release the pressure through the pressure relief valve to discharge the high-temperature and high-pressure eruptions. Therefore, the pressure relief channel of the existing pressure relief valve is generally short and straight to facilitate the flow of the eruptions and to achieve rapid pressure relief, which makes it easy for the pressure relief valve to open when triggered by external ball strikes or foreign objects, resulting in the inability to effectively ensure the sealing of the battery pack, which is easy to be invaded by the outside world, seriously affecting the safety of the battery. Utility Model Content

[0003] In order to overcome at least one defect of the above-mentioned prior art, the utility model provides a pressure relief component, which can effectively prevent the pressure relief component from opening due to external ball impact or foreign objects, so that the pressure relief component has an effective anti-accidental touch function.

[0004] According to an embodiment of the utility model, a pressure relief assembly includes: a valve body; an air intake channel, which is opened on the air intake side of the valve body; an exhaust channel, which is obliquely arranged between the air intake channel and the exhaust side of the valve body, and the exhaust side of the valve body is connected to the air intake channel through the exhaust channel; and a trigger member, which is closed in the air intake channel.

[0005] In the present pressure relief assembly, the exhaust passage is obliquely arranged between the air intake passage and the exhaust side of the valve body, which can effectively prevent external ball impact or foreign matter from triggering the trigger member in the air intake passage and causing the pressure relief assembly to open, so that the pressure relief assembly has an effective anti-accidental touch function.

[0006] According to some embodiments of the present invention, a guide portion is further included, wherein the guide portion is arranged on the air inlet side of the valve body, and the air inlet of the air inlet channel is communicated with the guide portion.

[0007] According to some embodiments of the present invention, the sum of the height of the air guide portion and the height of the air intake passage is smaller than the height of the exhaust passage.

[0008] According to some embodiments of the present utility model, the trigger member is arranged at the exhaust port of the air intake channel, the air outlet of the air intake channel or the middle part of the air intake channel.

[0009] According to some embodiments of the present invention, at least one flow blocking portion is further included, and the flow blocking portion is arranged in the exhaust passage.

[0010] According to some embodiments of the present invention, an angle between the exhaust passage and a plane where the exhaust side of the valve body is located is 25°-30°.

[0011] According to some embodiments of the present invention, there is a distance between the exhaust port of the exhaust channel and the projection of the intake channel on the plane where the exhaust side of the valve body is located.

[0012] Based on the same inventive concept, the utility model also proposes a battery pack, comprising: a box body, in which a battery module and a pressure relief chamber are arranged in sequence from top to bottom, the battery module is composed of a plurality of battery cells, and the pressure relief chamber is connected to the explosion-proof valve of the battery cell; a plurality of pressure relief components as described above, the pressure relief components are assembled at the bottom of the box body, and the air intake channel is connected to the pressure relief chamber.

[0013] In the present battery pack, a plurality of pressure relief assemblies are arranged at the bottom of the box body, so that the ejection material of the explosion-proof valve of the battery cell can be released from the pressure relief chamber from one or more adjacent pressure relief assemblies, thereby shortening the pressure relief path, effectively reducing the residence time of the high-temperature and high-pressure ejection material in the battery pack, reducing the impact of the thermal runaway battery cell on other battery cells, and the exhaust channel arranged at an angle can effectively prevent the accidental opening of the pressure relief assembly by external ball impact or foreign objects, thereby ensuring the sealing of the battery pack and preventing the inside of the battery pack from being invaded by the outside world, thereby ensuring the safety of the battery pack.

[0014] According to some embodiments of the utility model, the box body includes a bottom plate and a plurality of enclosures on the bottom plate that enclose at least one accommodating cavity, the battery module and the pressure relief cavity are arranged sequentially in the accommodating cavity along the pressure relief direction, and the pressure relief assembly is detachably connected to the bottom plate.

[0015] According to some embodiments of the utility model, the bottom plate is provided with an assembly through hole, and the pressure relief assembly is detachably connected to the assembly through hole.

[0016] According to some embodiments of the present invention, a support plate is further included, and the support plate is arranged between the box body and the battery core, so that the support plate and the box body enclose the pressure relief chamber.

[0017] According to some embodiments of the present invention, a plurality of weak parts are further included, wherein the weak parts are arranged on the support plate, and the explosion-proof valve of each battery cell has a weak part arranged opposite thereto.

[0018] According to some embodiments of the present invention, a plurality of pressure relief holes are further included. The pressure relief holes are opened on the support plate, and the explosion-proof valve of each battery cell has a pressure relief hole arranged opposite to it.

[0019] According to some embodiments of the present invention, an exhaust port of the exhaust channel faces the outside of the box.

[0020] In summary, the battery pack provided by the utility model has the following technical effects:

[0021] 1) By obliquely disposing the exhaust channel between the air intake channel and the exhaust side of the valve body, it is possible to effectively prevent external ball impact or foreign matter from triggering the trigger in the air intake channel and causing the pressure relief component to open, so that the pressure relief component has an effective anti-accidental touch function;

[0022] 2) By arranging a plurality of pressure relief components at the bottom of the box body, the ejection of the explosion-proof valve of the battery cell can be released from one or more adjacent pressure relief components through the pressure relief chamber, thereby shortening the pressure relief path, effectively reducing the time that the high-temperature and high-pressure ejection stays in the battery pack, and reducing the impact of the battery cell with thermal runaway on other battery cells. In addition, the exhaust channel arranged at an angle can effectively prevent the accidental opening of the pressure relief component by external ball impact or foreign matter, thereby ensuring the sealing of the battery pack and preventing the inside of the battery pack from being invaded by the outside world, thereby ensuring the safety of the battery pack;

[0023] 3) The exhaust port of the exhaust channel is directed toward the outside of the box body, so that the high-temperature and high-pressure eruptive substances can be guided by the exhaust channel and quickly move away from the battery pack toward the outside of the box body, thereby further reducing the time that the high-temperature and high-pressure eruptive substances stay around the battery pack and avoiding secondary damage to the battery pack by the high-temperature and high-pressure eruptive substances. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of a pressure relief assembly according to Embodiment 1 of the present utility model;

[0025] Figure 2 for Figure 1 AA direction cross-sectional view;

[0026] Figure 3 This is a schematic diagram of the geometric relationship of the pressure relief assembly of the first embodiment of the utility model;

[0027] Figure 4 This is a schematic diagram of the structure of a battery pack according to Embodiment 2 of the present utility model;

[0028] Figure 5 for Figure 4 BB direction cross-sectional view;

[0029] Figure 6 This is a schematic diagram of the structure of the support plate of an embodiment of the utility model;

[0030] Figure 7 It is a schematic structural diagram of a box body according to an embodiment of the utility model.

[0031] The meanings of the reference numerals are as follows:

[0032] 1. Box body; 11. Bottom plate; 12. Enclosure; 2. Pressure relief assembly; 21. Valve body; 22. Air intake channel; 23. Exhaust channel; 24. Flow guide; 25. Trigger; 3. Battery cell; 4. Pressure relief chamber; 41. Support plate; 42. Weak part. DETAILED DESCRIPTION

[0033] For better understanding and implementation, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0034] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0036] Embodiment 1:

[0037] See also Figure 1 and Figure 2 The utility model discloses a pressure relief assembly 2, which includes a valve body 21, an air intake channel 22, an exhaust channel 23 and a trigger 25. In this embodiment, the air intake channel 22 is opened at the air intake side of the valve body 21; the exhaust channel 23 is arranged obliquely between the air intake channel 22 and the exhaust side of the valve body 21, the exhaust side of the valve body 21 is communicated with the exhaust port of the exhaust channel 23, and the air intake of the exhaust channel 23 is communicated with the exhaust port of the air intake channel 22; the trigger 25 is closed in the air intake channel 22. Preferably, the exhaust channel 23 is arranged obliquely between the air intake channel 22 and the exhaust side of the valve body 21, which can effectively prevent the trigger 25 in the air intake channel 22 from being triggered by an external ball strike or foreign matter, thereby enabling the pressure relief assembly 2 to have an effective anti-mistouch function.

[0038] Optionally, the air intake side of the valve body 21 is connected to the exhaust side of the valve body 21 through the air intake channel 22 and the exhaust channel 23 in sequence, so that after the eruption breaks through the trigger member 25 sealed in the air intake channel 22, it passes through the air intake channel 22 and the exhaust channel 23 in sequence and is discharged to the outside; optionally, the trigger member 25 can be an aluminum film, and further, the trigger member 25 can be arranged at any position such as the exhaust port of the air intake channel 22, the air outlet of the air intake channel 22 or the middle of the air intake channel 22, so that the trigger member 25 can close the air intake channel 22; the air intake side of the valve body 21 can be connected to an external pressure relief pipe, a pressure relief chamber 4 and an explosion-proof valve of the battery cell 3, so that the eruption from the outside can flow to the air intake channel 22; optionally, the exhaust side of the valve body 21 can be directly connected to the external environment, a conveying pipe and a collecting cavity, so that the exhaust channel 23 can discharge the eruption.

[0039] See also Figure 1 and Figure 2 In this embodiment, it also includes a guide portion 24, which is arranged on the air inlet side of the valve body 21, and the air inlet of the air inlet channel 22 is connected to the guide portion 24. Preferably, the guide portion 24 is used to guide the external eruption, so that the eruption breaks through the trigger member 25 enclosed in the air inlet channel 22 and flows through the air inlet channel 22 and the exhaust hole in sequence, and is discharged to the outside. Optionally, the guide portion 24 is a sink structure, optionally, the guide portion 24 is a groove with a cross section larger than the cross section of the air inlet channel 22, so that the guide portion 24 can guide the fluid, and optionally, the guide portion 24 is a groove with an inner diameter that decreases in a direction away from the air inlet channel 22, so as to improve the guiding effect of the guide portion 24 on the eruption.

[0040] In the present embodiment, at least one flow blocking portion is further included, and the flow blocking portion is arranged in the exhaust channel 23. Optionally, the flow blocking portion can be a plurality of protrusions arranged in the exhaust channel 23, and the shape of the protrusions includes but is not limited to tooth-shaped, columnar, spherical, etc. Further, the flow blocking portion can change the flow path of the ejection in the exhaust channel 23, thereby adjusting the flow resistance of the exhaust channel 23, and then adjusting the flow rate of the ejection flowing out of the exhaust channel 23, and can effectively improve the protective effect of the exhaust channel 23 on the pressure relief component 2, reduce the probability of foreign objects intruding into the air intake channel 22, and further optimize the anti-accidental touch function of the pressure relief component 2.

[0041] In this embodiment, in order to release pressure quickly, the length of each channel on the valve body should be as small as possible (but not zero), so as to shorten the time that the ejected material stays in the valve body and improve the pressure relief efficiency. Furthermore, the sum of the depth of the guide portion 24 and the depth of the air inlet channel 22 is less than the depth of the exhaust channel 23, so as to shorten the time that the ejected material stays in the guide portion 24 and the air inlet channel 22, so that the ejected material enters the exhaust channel 23 as quickly as possible and is discharged from the exhaust channel 23. The depth of the guide portion 24 is the distance from the air inlet to the exhaust port of the guide portion 24 along the thickness direction of the valve body 21, such as Figure 3 H1 in; the depth of the air inlet channel 22 is the distance from the air inlet of the air inlet channel 22 to the exhaust port along the thickness direction of the valve body 21, such as Figure 3 H2 in; the depth of the exhaust channel 23 is the distance from the air inlet to the exhaust port of the exhaust channel 23 along the thickness direction of the valve body 21, such as Figure 3 H in.

[0042] See also Figure 1 and Figure 2 In this embodiment, the angle between the exhaust channel 23 and the plane where the exhaust side of the valve body 21 is located is α. In order to quickly release pressure, the length of the exhaust channel 23 should be shortened as much as possible, that is, the angle α should be appropriately increased. Preferably, the maximum value of the angle α is 30°, but the actual diversion situation and the anti-mistouch effect of the trigger member 25 must be considered. The angle between the exhaust channel 23 and the plane where the exhaust side of the valve body 21 is located is 25°-30°, that is, 25°≤α≤30°.

[0043] See also Figure 1 and Figure 2 In this embodiment, there is a distance between the exhaust port of the exhaust channel 23 and the projection of the intake channel 22 on the plane where the exhaust side of the valve body 21 is located. That is, the exhaust port of the exhaust channel 23 and the projection of the intake channel 22 on the plane where the exhaust side of the valve body 21 is located do not overlap, thereby preventing foreign matter from passing through the exhaust channel 23 and directly piercing the trigger member 25 closed in the intake channel 22, so that the inclined exhaust channel 23 can effectively prevent foreign matter from triggering the trigger member 25 in the intake channel 22 and causing the pressure relief assembly 2 to open.

[0044] Embodiment 2:

[0045] See also Figure 4 and Figure 5The utility model discloses a battery pack, which includes a box body 1 and a plurality of pressure relief components 2 as described in the first embodiment. In this embodiment, a battery module and a pressure relief chamber 4 are arranged in sequence from top to bottom in the box body 1. The battery module is composed of a plurality of battery cells 3. The pressure relief chamber 4 is connected to the explosion-proof valve of the battery cell 3. The pressure relief component 2 is assembled at the bottom of the box body 1, and the air inlet channel 22 is connected to the pressure relief chamber 4. Preferably, a plurality of pressure relief components 2 are arranged at the bottom of the box body 1, so that the ejection material of the explosion-proof valve of the battery cell 3 can be released from the adjacent one or more pressure relief components 2 through the pressure relief chamber 4, thereby shortening the pressure relief path, effectively reducing the residence time of the high-temperature and high-pressure ejection material in the battery pack, reducing the impact of the thermal runaway battery cell 3 on other battery cells 3, and the exhaust channel 23 is arranged at an angle, which can effectively prevent the pressure relief component 2 from being accidentally opened by external ball impact or foreign objects, thereby ensuring the sealing of the battery pack and preventing the inside of the battery pack from being invaded by the outside, thereby ensuring the safety of the battery pack.

[0046] Optionally, the exhaust channel 23 is directly connected to the outside world. When the battery cell 3 thermally runs away, after the ejection material of its explosion-proof valve enters the pressure relief chamber 4, under the guiding effect of the adjacent guide part 24, the ejection material will break through the corresponding trigger member 25, flow through the intake channel 22 and the exhaust channel 23 in turn, and be discharged to the outside world, thereby shortening the pressure relief path, reducing the time that the high-temperature and high-pressure gas stays in the battery pack, and avoiding the heat from spreading to other battery cells 3.

[0047] See also Figure 7In the present embodiment, the box body 1 includes a bottom plate 11 and a plurality of enclosures 12 on the bottom plate 11 that enclose at least one accommodating cavity. The battery module and the pressure relief cavity 4 are sequentially arranged in the accommodating cavity along the pressure relief direction, and the pressure relief assembly 2 is detachably connected to the bottom plate 11. Optionally, the pressure relief assembly 2 can be assembled to the bottom plate 11 by a detachable connection method such as a bolt connection or a snap connection, so as to facilitate the later maintenance and replacement of the pressure relief assembly 2. Preferably, a plurality of assembly through holes penetrating the bottom plate 11 are distributed on the bottom plate 11, and the pressure relief assembly 2 is detachably connected to the assembly through holes. Furthermore, the pressure relief assembly 2 is sealed to the bottom plate 11 to ensure the sealing of the battery pack. Optionally, a sealant is provided between the valve body 21 and the assembly through hole to ensure that the valve body 21 A sealed connection is formed between the battery pack and the assembly through hole, thereby improving the IP level of the battery pack, preventing the interior of the battery pack from being invaded by the outside world, and ensuring the safety of the battery pack; optionally, the explosion-proof valve of the battery cell 3 is arranged on the side of the battery cell 3 close to the bottom plate 11, so that when the battery cell 3 thermally runs away, the ejection material of the explosion-proof valve can directly enter the pressure relief chamber 4 along the ejection direction, and under the guiding action of the adjacent guide part 24, the ejection material will break through the corresponding trigger member 25, flow through the intake channel 22 and the exhaust channel 23 in turn, and be discharged to the outside.

[0048] Optionally, a plurality of the pressure relief components 2 are distributed at intervals on the bottom plate 11; further, when there is more than one battery module in the accommodating cavity, the quantity relationship between the pressure relief components 2 and the battery modules can be one or more of one-to-one, many-to-one and one-to-many. Preferably, each battery module is provided with two or more pressure relief components 2 in correspondence. Optionally, when the number of the pressure relief components 2 is multiple, the pressure relief components 2 are distributed at equal intervals.

[0049] See also Figure 5 , Figure 6 and Figure 7 In this embodiment, a support plate 41 is further included, and the support plate 41 is arranged between the box body 1 and the battery cell 3, so that the support plate 41 and the box body 1 enclose the pressure relief chamber 4. Preferably, the support plate 41 is spaced apart from the box body 1 to form the pressure relief chamber 4. When the battery cell 3 is thermally runaway, the ejected material flows through the support plate 41 into the pressure relief chamber 4, and under the guiding effect of the adjacent guide portion 24, the corresponding trigger member 25 is broken, and flows through the intake channel 22 and the exhaust channel 23 in sequence, and is discharged to the outside.

[0050] See also Figure 5 , Figure 6 and Figure 7In this embodiment, it also includes a plurality of weak parts 42, which are arranged on the support plate 41, and each explosion-proof valve of the battery cell 3 has a weak part 42 arranged opposite to it. Preferably, when the battery cell 3 is thermally runaway, the ejection of the explosion-proof valve of the battery cell 3 directly enters the pressure relief chamber 4 from the weak part 42, and under the guiding effect of the adjacent guide part 24, the high-temperature and high-pressure gas breaks the corresponding trigger member 25, flows through the intake channel 22 and the exhaust channel 23 in turn, and is discharged to the outside, thereby shortening the pressure relief path, reducing the time that the high-temperature and high-pressure ejection stays in the battery pack, and preventing heat from spreading to other battery cells 3. Furthermore, the weak part 42 can be replaced by a pressure relief hole, that is, the support plate 41 is provided with a plurality of pressure relief holes, and each explosion-proof valve of the battery cell 3 has a pressure relief hole arranged opposite to it. When the battery cell 3 is in thermal runaway, the ejection material of the explosion-proof valve of the battery cell 3 directly enters the pressure relief chamber 4 from the pressure relief hole, and under the guiding effect of the adjacent guide part 24, the high-temperature and high-pressure gas breaks through the corresponding trigger member 25, flows through the intake channel 22 and the exhaust channel 23 in sequence, and is discharged to the outside, thereby shortening the pressure relief path, reducing the time that the high-temperature and high-pressure ejection material stays in the battery pack, and preventing heat from spreading to other battery cells 3.

[0051] See also Figure 4 and Figure 5 In this embodiment, the exhaust port of the exhaust channel 23 faces the outside of the box body 1. When the battery cell 3 is in thermal runaway, the ejection of the explosion-proof valve of the battery cell 3 directly enters the pressure relief chamber 4 from the weak portion 42 or the pressure relief hole. Under the guiding effect of the adjacent guide portion 24, the ejection breaks through the corresponding trigger member 25, and flows through the intake channel 22 and the exhaust channel 23 in sequence, and is discharged to the outside, thereby shortening the pressure relief path, reducing the time that the high-temperature and high-pressure ejection stays in the battery pack, and preventing the heat from spreading to other battery cells 3. Moreover, under the guiding effect of the exhaust channel 23 with the exhaust port facing the outside of the box body 1, the high-temperature and high-pressure ejection can quickly move away from the battery pack toward the outside of the box body 1, further reducing the time that the high-temperature and high-pressure ejection stays around the battery pack, and preventing the high-temperature and high-pressure ejection from causing secondary damage to the battery pack.

[0052] The technical means disclosed in the solution of the utility model are not limited to the technical means disclosed in the above-mentioned implementation mode, but also include technical solutions composed of any combination of the above technical features. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model, and these improvements and modifications are also regarded as the protection scope of the utility model.

Claims

1. A pressure relief assembly, characterized in that: include: Valve body (21); An air intake passage (22), the air intake passage (22) being opened on the air intake side of the valve body (21); an exhaust passage (23), the exhaust passage (23) being arranged obliquely between the intake passage (22) and the exhaust side of the valve body (21), the exhaust side of the valve body (21) being in communication with the intake passage (22) through the exhaust passage (23); A triggering member (25), wherein the triggering member (25) is sealed in the air inlet passage (22).

2. The pressure relief assembly according to claim 1, characterized in that: It also comprises a guide portion (24), the guide portion (24) being arranged on the air inlet side of the valve body (21), and the air inlet of the air inlet channel (22) being in communication with the guide portion (24).

3. The pressure relief assembly according to claim 2, characterized in that: The sum of the height of the guide portion (24) and the height of the air intake channel (22) is smaller than the height of the exhaust channel (23).

4. The pressure relief assembly according to claim 1, characterized in that: The trigger member (25) is arranged at the exhaust port of the air intake channel (22), the air outlet of the air intake channel (22) or the middle part of the air intake channel (22).

5. The pressure relief assembly according to claim 1, characterized in that: It also includes at least one flow blocking portion, which is arranged in the exhaust passage (23).

6. The pressure relief assembly according to claim 1, characterized in that: The included angle between the exhaust passage (23) and the plane where the exhaust side of the valve body (21) is located is 25°-30°.

7. The pressure relief assembly according to claim 1, characterized in that: There is a distance between the exhaust port of the exhaust channel (23) and the projection of the intake channel (22) on the plane where the exhaust side of the valve body (21) is located.

8. A battery pack, characterized in that: include: A box body (1), wherein a battery module and a pressure relief chamber (4) are arranged in sequence from top to bottom in the box body (1), the battery module is composed of a plurality of battery cells (3), and the pressure relief chamber (4) is connected to an explosion-proof valve of the battery cell (3); A plurality of pressure relief assemblies (2) according to any one of claims 1 to 7, wherein the pressure relief assembly (2) is mounted on the bottom of the housing (1), and the air inlet passage (22) is connected to the pressure relief chamber (4).

9. The battery pack according to claim 8, characterized in that: The box body (1) comprises a bottom plate (11) and a plurality of enclosure plates (12) on the bottom plate (11) that enclose at least one accommodating cavity, the battery module and the pressure relief cavity (4) being arranged in sequence in the accommodating cavity along a pressure relief direction, and the pressure relief assembly (2) being detachably connected to the bottom plate (11).

10. The battery pack according to claim 9, characterized in that: The bottom plate (11) is provided with an assembly through hole (13), and the pressure relief assembly (2) is detachably connected to the assembly through hole (13).

11. The battery pack according to claim 8, characterized in that: It also comprises a support plate (41), wherein the support plate (41) is arranged between the box body (1) and the battery core (3), so that the support plate (41) and the box body (1) enclose the pressure relief chamber (4).

12. The battery pack according to claim 11, characterized in that: It also comprises a plurality of weak parts (42), wherein the weak parts (42) are arranged on the support plate (41), and the explosion-proof valve of each battery cell (3) has a weak part (42) arranged opposite thereto.

13. The battery pack according to claim 11, characterized in that: It also comprises a plurality of pressure relief holes, wherein the pressure relief holes are opened on the support plate (41), and the explosion-proof valve of each battery cell (3) has a pressure relief hole arranged opposite thereto.

14. The battery pack according to any one of claims 8 to 13, characterized in that: The exhaust port of the exhaust passage (23) faces the outside of the box body (1).

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