Pressure relief valve and battery pack

Abstract

The present application provides a pressure relief valve and a battery pack. The pressure relief valve comprises a valve body; a through pressure relief hole is formed in the valve body; whistle holes are formed on the outer peripheral surface of the valve body; the whistle holes extend to the inner peripheral surface of the pressure relief hole, and form, on the inner peripheral surface, openings communicated with the pressure relief hole. The whistle holes are configured to produce a sound when allowing part of gas in the pressure relief hole to be discharged.

Description

Pressure relief valve and battery pack

[0001] The present application claims priority to the Chinese patent application No. 202421313834.3, filed on June 7, 2024, to the Chinese Patent Office, the whole content of the above application being incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of battery, in particular to a pressure relief valve and a battery pack. BACKGROUND

[0003] In the related art, when a battery module in a battery pack experiences thermal runaway, a battery management system (BMS) in the battery pack sends a thermal runaway fault signal for prompt. SUMMARY

[0004] However, in practical applications, when the battery module experiences thermal runaway, the high-temperature gas ejected from the battery cell of the battery module can damage the battery management system, resulting in the battery management system being unable to send a thermal runaway fault signal in time for prompt.

[0005] The present application provides a pressure relief valve. The pressure relief valve comprises a valve body, the valve body is provided with a through-going pressure relief hole, the outer circumferential surface of the valve body is provided with a whistle hole, the whistle hole extends to the inner circumferential surface of the pressure relief hole and forms an opening in communication with the pressure relief hole on the inner circumferential surface, and the whistle hole is configured to produce a sound when part of the gas in the pressure relief hole is discharged.

[0006] The present application also provides a battery pack, comprising:

[0007] a housing, the housing comprising a cavity;

[0008] a battery module, arranged in the cavity;

[0009] a pressure relief valve, the pressure relief valve being as described above, the pressure relief valve comprising a valve body, the valve body being provided with a through-going pressure relief hole, the outer circumferential surface of the valve body being provided with a whistle hole, the whistle hole extending to the inner circumferential surface of the pressure relief hole and forming an opening in communication with the pressure relief hole on the inner circumferential surface, the whistle hole being configured to produce a sound when part of the gas in the pressure relief hole is discharged, the pressure relief valve being connected with the housing, and the pressure relief hole of the valve body being configured to communicate the cavity with the outside of the housing. ADVANTAGEOUS EFFECTS

[0010] The pressure relief valve provided in the application is provided with a whistle hole communicated with the pressure relief hole on the outer circumferential surface of the valve body. When thermal runaway occurs in the battery module, the high-temperature gas sprayed out of the battery cell is discharged to the outside of the shell of the battery pack through the pressure relief hole. In this process, a part of the high-temperature gas is discharged from the whistle hole of the valve body at a high speed and a sound signal is generated. Even if the battery management system fails to send a thermal runaway fault signal in time for prompt, the sound signal generated by the pressure relief valve can also be prompted.

[0011] The battery pack provided in the application is provided with a whistle hole communicated with the pressure relief hole on the outer circumferential surface of the valve body of the pressure relief valve. When thermal runaway occurs in the battery module, the high-temperature gas sprayed out of the battery cell is discharged to the outside of the shell of the battery pack through the pressure relief hole. In this process, a part of the high-temperature gas is discharged from the whistle hole of the valve body at a high speed and a sound signal is generated. Even if the battery management system fails to send a thermal runaway fault signal in time for prompt, the sound signal generated by the pressure relief valve can also be prompted, improving the safety of the battery pack. BRIEF DESCRIPTION OF DRAWINGS

[0012] FIG. 1 is a structural schematic view of one embodiment of the pressure relief valve provided in the application;

[0013] FIG. 2 is another angle view of one embodiment of the pressure relief valve provided in the application;

[0014] FIG. 3 is a sectional view of one embodiment of the pressure relief valve provided in the application, wherein the sectional view is along the inlet to outlet direction of the pressure relief hole;

[0015] FIG. 4 is an exploded structural schematic view of the pressure relief valve provided in the application;

[0016] FIG. 5 is a sectional view of one embodiment of the valve body and the flow dividing part provided in the application, wherein the sectional view is along the inlet to outlet direction of the pressure relief hole;

[0017] FIG. 6 is a structural schematic view of one embodiment of the battery pack provided in the application;

[0018] FIG. 7 is a sectional view of one embodiment of the battery pack provided in the application, wherein the sectional view is along the inlet to outlet direction of the pressure relief hole.

[0019] Explanation of reference signs:

[0020] Battery pack 10; housing 11; cavity 12; battery module 13; pressure relief valve 100; valve body 110; pressure relief hole 1100; inlet 1101; outlet 1102; inner peripheral surface 1103; outer peripheral surface 1104; first hole section 1110; second hole section 1120; flow channel 1121; whistle hole 1130; opening 1131; inclined surface 111; side surface 112; flow dividing portion 120; flow dividing plate 121; sharp portion 130; sharp end 131; connecting end 132; clamping portion 140; mounting protrusion 150; sealing film 160; sealing member 170. Embodiments of the present application

[0021] In the description of the present application, unless specifically defined and limited otherwise, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0022] In the present application, unless specifically defined and limited otherwise, the first feature "on" or "below" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, and the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, and the horizontal height of the first feature is less than that of the second feature.

[0023] In the description of the present embodiment, the terms "up", "down", "left", "right", "front", "back" and other orientation or position relationships are based on the orientation or position relationship shown in the drawings, which is for the convenience of description and simplification of operation, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used to distinguish the description and have no special meaning.

[0024] In the related art, when a battery module in a battery pack experiences thermal runaway, a battery management system (BMS) in the battery pack sends a thermal runaway fault signal for prompt. However, in actual application, when the battery module experiences thermal runaway, high-temperature gas ejected from the battery cell of the battery module can damage the battery management system, so that the battery management system cannot send the thermal runaway fault signal in time for prompt. In addition, when the battery pack is subjected to extrusion or puncture, the battery management system can be damaged first, and when the battery module experiences thermal runaway later, the battery management system cannot send the thermal runaway fault signal in time for prompt.

[0025] When the battery pack is used for a vehicle, if the battery management system does not send the thermal runaway fault signal in time for prompt when the battery module experiences thermal runaway, not only property loss will be caused, but also the escape time of the people in the vehicle will be shortened, and in severe cases, a safety accident can even be caused.

[0026] To improve the above problems, an embodiment of the present application provides a pressure relief valve. The pressure relief valve is used for a battery pack.

[0027] As shown in FIGS. 1, 6 and 7, the pressure relief valve 100 includes a valve body 110, the valve body 110 is provided with a through pressure relief hole 1100, the pressure relief valve 100 is configured to be connected with an outer shell 11 of a battery pack 10, the pressure relief hole 1100 of the valve body 110 is configured to communicate a cavity 12 of the outer shell 11 with the outside of the outer shell 11. As shown in FIGS. 1 and 5, the pressure relief hole 1100 includes opposite inlet 1101 and outlet 1102, when the pressure relief valve 100 is connected with the outer shell 11, the inlet 1101 of the pressure relief hole 1100 is communicated with the cavity 12 of the outer shell 11, and the outlet 1102 of the valve body 110 is communicated with the outside of the outer shell 11. A battery module 13 (not shown in the figure) is arranged in the cavity 12 of the outer shell 11. When the battery module 13 experiences thermal runaway, high-temperature gas ejected from the battery cell of the battery module 13 can be discharged to the outside of the outer shell 11 of the battery pack 10 through the pressure relief hole 1100, so as to reduce the pressure in the outer shell 11.

[0028] In some possible implementation manners, as shown in FIGS. 1 to 5, a whistle hole 1130 can be arranged on the outer circumferential surface 1104 of the valve body 110, the whistle hole 1130 extends to the inner circumferential surface 1103 of the pressure relief hole 1100, and forms an opening 1131 communicated with the pressure relief hole 1100 on the inner circumferential surface 1103, wherein the whistle hole 1130 is configured to produce sound when part of the gas in the pressure relief hole 1100 is discharged.

[0029] The pressure relief valve 100 provided by the embodiments of the present application is provided with a whistle hole 1130 communicated with the pressure relief hole 1100 on the outer circumferential surface 1104 of the valve body 110. When the battery module 13 is in thermal runaway, the high-temperature gas sprayed from the battery cell of the battery module 13 is discharged to the outside of the shell 11 of the battery pack 10 along the direction indicated by the arrow in FIG. 5 through the pressure relief hole 1100. In this process, a part of the high-temperature gas is discharged from the whistle hole 1130 of the valve body 110 at a high speed and a sound signal is generated. Even if the battery management system fails to send a thermal runaway fault signal in time for prompting, the sound signal generated by the pressure relief valve 100 can be used for prompting. The high-speed gas flowing through the whistle hole 1130 can be made to generate turbulence to produce sound, or the high-speed gas flowing through the whistle hole 1130 can be made to make the edge of the opening 1131 vibrate at a high speed to produce sound, which can be determined according to the structure of the whistle hole 1130.

[0030] In some possible implementation manners, the valve body 110 can include an inclined surface 111 located on one side of the whistle hole 1130 along the direction from the inlet 1101 to the outlet 1102, the inclined surface 111 extending from the outer circumferential surface 1104 of the valve body 110 to the edge of the opening 1131 of the whistle hole 1130, and in the direction from the outlet 1102 to the inlet 1101 of the pressure relief hole 1100, the inclined surface 111 is inclined toward the pressure relief hole 1100. In this way, when the high-speed airflow in the pressure relief hole 1100 flows through the whistle hole 1130, it is easier to form a spiral vortex in the whistle hole 1130, so that the gas vibrates rapidly and a larger sound is generated.

[0031] As shown in FIGS. 1, 3 and 5, the valve body 110 can also include a side surface 112 located on one side of the whistle hole 1130 along the direction from the outlet 1102 to the inlet 1101, the side surface 112 extending from the outer circumferential surface 1104 of the valve body 110 to the edge of the opening 1131 of the whistle hole 1130. The side surface 112 is connected with the inclined surface 111 and encloses the whistle hole 1130. The side surface 112 can be substantially perpendicular to the direction from the inlet 1101 to the outlet 1102 of the valve body 110.

[0032] In some possible implementation manners, the number of whistle holes 1130 on the valve body 110 can be multiple. The multiple whistle holes 1130 respectively extend from the outer circumferential surface 1104 of the valve body 110 to the inner circumferential surface 1103 of the pressure relief hole 1100, and respectively form openings 1131 communicated with the pressure relief hole 1100 on the inner circumferential surface 1103 of the pressure relief hole 1100. When the high-temperature gas sprayed from the battery cell of the battery module 13 is discharged to the outside of the shell 11 of the battery pack 10 through the pressure relief hole 1100, a part of the high-speed gas in the pressure relief hole 1100 is discharged from the multiple whistle holes 1130 and sound is generated, thereby improving the total volume of the sound.

[0033] The plurality of whistles 1130 can be arranged along the circumference of the valve body 110, so that the gas in the pressure relief hole 1100 has a high speed when being discharged from the plurality of whistles 1130, and the sound generated has a high volume. Moreover, the plurality of whistles 1130 are arranged along the circumference of the valve body 110, which does not increase the length of the valve body 110 from the inlet 1101 to the outlet 1102 of the pressure relief hole 1100.

[0034] Of course, the plurality of whistles 1130 can also be arranged in sequence along the direction from the inlet 1101 to the outlet 1102 of the pressure relief hole 1100. When the high-temperature gas ejected from the battery cell of the battery module 13 is discharged to the outside of the shell 11 of the battery pack 10 through the pressure relief hole 1100, a part of the high-speed gas in the pressure relief hole 1100 can also be discharged from the plurality of whistles 1130 and generate sound.

[0035] It should be noted that the shapes of the plurality of whistles 1130 opened in the valve body 110 can be the same or different, as long as a part of the gas in the pressure relief hole 1100 can generate sound when being discharged from the whistle 1130. Of course, the former can make the plurality of whistles 1130 more convenient.

[0036] In some possible implementation manners, as shown in FIGS. 1, 3 and 5, the pressure relief valve 100 can further include a flow dividing portion 120 arranged in the pressure relief hole 1100, which divides the pressure relief hole 1100 into a plurality of flow channels 1121. The gas entering from the inlet 1101 of the pressure relief hole 1100 is divided into different flow channels 1121. The plurality of flow channels 1121 can be arranged along the circumference of the valve body 110, and the plurality of flow channels 1121 and the openings 1131 of the plurality of whistles 1130 are in one-to-one correspondence and in communication. In this way, a part of the high-speed gas in each flow channel 1121 can be discharged from the corresponding whistle 1130, and the sounds generated by the high-speed gas discharged from the plurality of whistles 1130 do not interfere with each other, which is conducive to improving the volume of the sound generated by the high-speed gas discharged from the whistle 1130.

[0037] The flow channel 1121 can be located between the inlet 1101 and the outlet 1102 of the pressure relief hole 1100, and has a spacing from the inlet 1101 and the outlet 1102 of the pressure relief hole 1100. Alternatively, the flow channel 1121 can extend from the inlet 1101 to the outlet 1102 of the pressure relief hole 1100.

[0038] In some possible implementation manners, the flow distribution portion 120 can include a plurality of flow distribution plates 121 arranged along the circumference of the valve body 110, and two adjacent flow distribution plates 121 and the inner circumferential surface 1103 of the pressure relief hole 1100 together form a flow channel 1121. Specifically, one side edge of the plurality of flow distribution plates 121 extends along the direction from the inlet 1101 to the outlet 1102 of the pressure relief hole 1100 and is connected together, and two adjacent flow distribution plates 121 are arranged at an angle, and the other side of the plurality of flow distribution plates 121 is respectively connected with the inner circumferential surface 1103 of the pressure relief hole 1100, so that two adjacent flow distribution plates 121 and the inner circumferential surface 1103 of the pressure relief hole 1100 together form a flow channel 1121. In this way, the other side edge of the flow distribution plate 121 can be integrally connected with the valve body 110, so as to improve the connection stability of the flow distribution portion 120 and the valve body 110, and the flow distribution portion 120 can stably distribute the gas in the pressure relief hole 1100.

[0039] As shown in FIGS. 1-4, the pressure relief valve 100 can further include a sealing film 160 connected with the valve body 110, and the sealing film 160 closes the inlet 1101 to prevent impurities such as water and dust from entering the cavity 12 in the shell 11 of the battery pack 10 through the pressure relief hole 1100 of the pressure relief valve 100. In this way, the sealing film 160 can be a waterproof and breathable film, so that the gas can pass through the sealing film 160, and the impurities such as water and dust are prevented from entering the cavity 12 through the pressure relief hole 1100, so as to maintain the pressure difference between the cavity 12 in the shell 11 and the outside, and avoid the situation that the battery module 13 in the cavity 12 does not appear thermal runaway, but the pressure in the cavity 12 is too high, and the sealing film 160 is broken due to the high temperature and high pressure.

[0040] In this way, the sharp portion 130 can be arranged on the valve body 110 of the pressure relief valve 100, and the sharp portion 130 is located on one side of the sealing film 160 along the direction from the inlet 1101 to the outlet 1102 of the pressure relief hole 1100, and the sharp portion 130 is configured to pierce the sealing film 160. In this way, when the battery module 13 in the cavity 12 of the shell 11 appears thermal runaway, the pressure in the cavity 12 of the shell 11 rapidly increases, and the sealing film 160 is deformed and expanded towards the sharp portion 130. When the sealing film 160 is deformed to contact the sharp portion 130, the sharp portion 130 pierces the sealing film 160, so that the high-temperature and high-pressure gas in the cavity 12 rapidly passes through the pressure relief hole 1100 and is discharged, and part of the high-pressure gas in the pressure relief hole 1100 is discharged through the whistle hole 1130 and produces sound.

[0041] In some possible implementation manners, the sharp portion 130 can be arranged on one side of the flow distribution portion 120 facing the sealing film 160, so that the sharp portion 130 is arranged more conveniently, and there is no need to additionally arrange a fixing structure in the pressure relief hole 1100 to fix the sharp portion 130.

[0042] Specifically, the sharp part 130 is located in the pressure relief hole 1100. The sharp part 130 includes a sharp end 131 and a connecting end 132, and the sharp end 131 and the connecting end 132 of the sharp part 130 are sequentially arranged at two ends of the sharp part 130 along the direction from the inlet 1101 to the outlet 1102 of the pressure relief hole 1100. The sharp end 131 of the sharp part 130 faces the sealing film 160. The connecting end 132 of the sharp part 130 is connected to the side of the shunt part 120 facing the sealing film 160. Among them, the sharp part 130 is located at the side edge where the plurality of shunt plates 121 are connected to each other, so that the sharp part 130 is generally located at the center position of the pressure relief hole 1100, and when the sharp part 130 contacts the expanded sealing film 160, the sharp part 130 can pierce the sealing film 160 from the center position of the sealing film 160.

[0043] As shown in FIGS. 3 and 5, the pressure relief hole 1100 includes a first hole section 1110 and a second hole section 1120 arranged along the direction from the inlet 1101 to the outlet 1102, and the opening 1131 of the whistle hole 1130 is located in the second hole section 1120, that is, the opening 1131 of the whistle hole 1130 communicates with the second hole section 1120. The high-speed gas entering from the inlet 1101 of the pressure relief hole 1100 first flows through the first hole section 1110 and then enters the second hole section 1120. Part of the high-speed gas in the second hole section 1120 is discharged through the whistle hole 1130 and produces sound, and another part of the high-speed gas in the second hole section 1120 flows along the second hole section 1120 to the outlet 1102 of the pressure relief hole 1100.

[0044] In some possible implementations, the radial cross-sectional area of the first hole section 1110 of the pressure relief hole 1100 can be less than the radial cross-sectional area of the second hole section 1120. The whistle hole 1130 reduces the radial cross-sectional area of the first hole section 1110, so that the gas flow speed in the first hole section 1110 is higher, and thus the gas flow rate transmitted from the first hole section 1110 to the second hole section 1120 and discharged through the whistle hole 1130 is increased, so as to produce sound with higher volume.

[0045] It should be noted that the radial cross-sections of the first hole section 1110 and the second hole section 1120 refer to the areas of the regions enclosed by the profile lines formed by the intersection between the inner circumferential surfaces of the first hole section 1110 and the second hole section 1120 and the planes perpendicular to the direction from the inlet 1101 to the outlet 1102 of the pressure relief hole 1100.

[0046] Among them, the radial cross-sectional area of the first hole section 1110 can be less than or equal to 80 mm 2 , so that the gas flowing through the first hole section 1110 has a relatively high speed. The radial cross-sectional area of the first hole section 1110 can be 75 mm 2 , 60 mm 2 , 50 mm 2 , 30 mm 2etc., which can be determined according to the type of the battery pack 10.

[0047] In addition, the radial cross-sectional area of the first hole section 1110 can be greater than or equal to 12 mm 2 to avoid the radial cross-sectional area of the first hole section 1110 being too small, so that when the battery module 13 is in thermal runaway, the high-temperature and high-pressure gas in the cavity 12 cannot be discharged in time through the pressure relief hole 1100. The radial cross-sectional area of the first hole section 1110 can be 20 mm 2 , 25 mm 2 , 40 mm 2 , 45 mm 2 etc., which can be determined according to the type of the battery pack 10.

[0048] In some possible implementations, the minimum distance between the end of the first hole section 1110 away from the inlet 1101 and the opening 1131 of the whistle hole 1130 can be less than or equal to 6 mm. In this way, the opening 1131 of the whistle hole 1130 can be closer to the first hole section 1110, so that when the gas at a high speed is discharged from the end of the first hole section 1110 away from the inlet 1101 of the pressure relief hole 1100, a part of the gas can quickly enter the whistle hole 1130 and be discharged through the whistle hole 1130 to produce a sound with a high volume. The minimum distance between the end of the first hole section 1110 away from the inlet 1101 and the opening 1131 of the whistle hole 1130 can be less than 5.5 mm, 4 mm, etc., which can be determined according to the structure of the valve body 110.

[0049] In addition, the minimum distance between the end of the first hole section 1110 away from the inlet 1101 and the opening 1131 can be greater than or equal to 3 mm. In this way, the opening 1131 of the whistle hole 1130 can be prevented from being too close to the first hole section 1110, so that the opening 1131 of the whistle hole 1130 is not blocked by the step at the connection between the first hole section 1110 and the second hole section 1120, and the gas discharged from the end of the first hole section 1110 away from the inlet 1101 of the pressure relief hole 1100 can enter the whistle hole 1130 through the opening 1131, or the amount of gas entering is too small to produce a sound. The minimum distance between the end of the first hole section 1110 away from the inlet 1101 and the opening 1131 of the whistle hole 1130 can be less than 3.5 mm, 4.5 mm, etc., which can be determined according to the structure of the valve body 110.

[0050] In some possible implementation manners, when the pressure relief valve 100 comprises the shunt portion 120, the shunt portion 120 can be located at the second hole section 1120, so that the shunt portion 120 divides the second hole section 1120 into a plurality of flow channels 1121. Specifically, the other side of each of the plurality of shunt plates 121 of the shunt portion 120 can be connected with the inner circumferential surface of the second hole section 1120, so that the adjacent two shunt plates 121 and the inner circumferential surface of the second hole section 1120 together form a flow channel 1121. The shunt plate 121 can extend from the second hole section 1120 to the outlet 1102 of the pressure relief hole 1100, away from the first hole section 1110. Thus, the gas discharged from the first hole section 1110 away from the inlet 1101 of the pressure relief hole 1100 can immediately enter the flow channel 1121, and the gas in the flow channel 1121 also has a high speed.

[0051] In some possible implementation manners, as shown in FIGS. 1 to 5, the pressure relief valve 100 can further comprise a clamping portion 140, which is protruded from the end face of the valve body 110 at the end provided with the inlet 1101. Thus, the pressure relief valve 100 can be quickly connected with the shell 11 by clamping the clamping portion 140 with the shell 11. The plurality of clamping portions 140 can be arranged along the circumference of the inlet 1101 to improve the connection stability of the pressure relief valve 100 and the shell 11.

[0052] In some possible implementation manners, as shown in FIGS. 2 to 4, the pressure relief valve 100 can further comprise a sealing member 170, which is arranged at the end of the valve body 110 provided with the inlet 1101. When the pressure relief valve 100 is connected with the shell 11, the gap between the valve body 110 and the shell 11 can be sealed by the sealing member 170. The sealing member 170 can be arranged opposite to the end face of the valve body 110 at the end provided with the inlet 1101, and when the pressure relief valve 100 is connected with the shell 11, the sealing member 170 is clamped between the shell 11 and the end face of the valve body 110 at the end provided with the inlet 1101, so as to seal the gap between the shell 11 and the end face of the valve body 110 at the end provided with the inlet 1101.

[0053] Specifically, the mounting protrusion 150 can be protruded from the end face of the valve body 110 at the end provided with the inlet 1101, and the mounting protrusion 150 extends along the circumference of the inlet 1101 to form an annular structure. The sealing member 170 is an annular sealing ring, and is sleeved on the mounting protrusion 150, so that the sealing member 170 is arranged opposite to the end face of the valve body 110 at the end provided with the inlet 1101. The plurality of clamping portions 140 are respectively protruded from the end of the mounting protrusion 150 away from the valve body 110, and are arranged along the circumference of the mounting protrusion 150.

[0054] Continuing to refer to FIGS. 2-4, the inlet 1101 edge of the valve body 110 has a spacing with the inner side surface 112 of the mounting protrusion 150. The sealing film 160 is located in the space enclosed by the mounting protrusion 150. The sealing film 160 is arranged on the end surface of the one end of the valve body 110 provided with the inlet 1101 and seals the inlet 1101. One side surface of the sealing film 160 can be pasted with the corresponding end surface of the valve body 110 by pasting.

[0055] The embodiments of the present application also provide a battery pack, which comprises a pressure relief valve, the specific structure of which is referred to the above embodiments. Since the battery pack adopts all the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0056] As shown in FIGS. 6 and 7, the battery pack 10 comprises a housing 11, a battery module 13 and a pressure relief valve 100. The housing 11 comprises a cavity 12, the battery module 13 is arranged in the cavity 12, and the pressure relief valve 100 is connected with the housing 11. The pressure relief hole 1100 of the valve body 110 of the pressure relief valve 100 is configured to communicate the cavity 12 of the housing 11 with the outside of the housing 11.

[0057] The battery pack 10 provided by the embodiments of the present application is configured to communicate the cavity 12 of the housing 11 with the outside of the housing 11 through the pressure relief hole 1100 of the valve body 110 of the pressure relief valve 100, and the peripheral surface 1104 of the valve body 110 is provided with a whistle hole 1130 communicating with the pressure relief hole 1100. When the battery module 13 occurs thermal runaway, the high-temperature gas ejected from the battery cell of the battery module 13 is discharged to the outside of the housing 11 of the battery pack 10 through the pressure relief hole 1100. In this process, a part of the high-temperature gas will be discharged from the whistle hole 1130 of the valve body 110 at a high speed and generate a sound signal. Even if the battery management system fails to send a thermal runaway fault signal in time for prompting, the sound signal generated by the pressure relief valve 100 can also be used for prompting.

Claims

1. A pressure relief valve, comprising a valve body, the valve body being provided with a pressure relief hole extending therethrough, and the outer circumferential surface of the valve body being provided with a whistle hole extending to the inner circumferential surface of the pressure relief hole and forming an opening in communication with the pressure relief hole, the whistle hole being configured to produce sound when part of the gas in the pressure relief hole is discharged.

2. The pressure relief valve of claim 1, wherein, The pressure relief hole comprises opposite inlet and outlet, the valve body comprises a bevel on one side of the whistle hole along the direction from the inlet to the outlet, the bevel extending from the outer circumferential surface to the edge of the opening, and the bevel is inclined towards the pressure relief hole in the direction from the outlet to the inlet.

3. The pressure relief valve of claim 1, wherein, The whistle hole is in plurality, and the plurality of whistle holes are arranged along the circumference of the valve body. 4.The pressure relief valve of claim 3, further comprising a flow dividing part arranged in the pressure relief hole, the flow dividing part dividing the pressure relief hole into a plurality of flow channels, the plurality of flow channels being arranged along the circumference of the valve body, and the plurality of flow channels being in one-to-one correspondence with the openings of the plurality of whistle holes.

5. The pressure relief valve of claim 4, wherein, The flow dividing part comprises a plurality of flow dividing plates arranged along the circumference of the valve body, and two adjacent flow dividing plates and the inner circumferential surface of the pressure relief hole form the flow channel.

6. The pressure relief valve of claim 5, wherein, The pressure relief hole comprises opposite inlet and outlet, one side edge of the plurality of flow dividing plates extends along the direction from the inlet to the outlet and is connected together, two adjacent flow dividing plates are arranged at an angle, and the other side edge of the plurality of flow dividing plates is respectively connected with the inner circumferential surface, so that two adjacent flow dividing plates and the inner circumferential surface form the flow channel.

7. The pressure relief valve of claim 6, wherein, The other side edge of the flow dividing plate is integrally connected with the valve body.

8. The pressure relief valve of claim 4, wherein, The pressure relief hole comprises opposite inlet and outlet, the pressure relief valve further comprises a sealing film connected with the valve body, the sealing film closes the inlet, and one side of the flow dividing part towards the sealing film is provided with a sharp part.

9. The pressure relief valve of claim 8, wherein, The sealing film is a waterproof and breathable film.

10. The pressure relief valve of claim 8, wherein, The sharp part comprises a sharp end and a connecting end, the sharp end is towards the sealing film, and the connecting end is connected with one side of the flow dividing part towards the sealing film.

11. The pressure relief valve of claim 8, wherein, The valve body comprises opposite inlet and outlet, and the sealing film is arranged on the end surface of the valve body provided with the inlet.

12. The pressure relief valve of any one of claims 1 to 11, wherein, The pressure relief hole comprises opposite inlet and outlet, the pressure relief hole comprises a first hole section and a second hole section arranged along the direction from the inlet to the outlet, the opening is located in the second hole section, and the radial cross-sectional area of the first hole section is smaller than the radial cross-sectional area of the second hole section.

13. The pressure relief valve of claim 12, wherein, the radial cross-sectional area of the first hole section is greater than or equal to 12 mm 2 ; the radial cross-sectional area of the first hole section is less than or equal to 80 mm 2 .

14. The pressure relief valve of claim 12, wherein, The minimum distance between the end of the first hole section away from the inlet and the opening is less than or equal to 6mm, and the minimum distance between the end of the first hole section away from the inlet and the opening is greater than or equal to 3mm. 15.The pressure relief valve of claim 12, further comprising a flow dividing part arranged in the second hole section and dividing the second hole section into a plurality of flow channels, the plurality of flow channels being arranged along the circumference of the valve body, and the plurality of flow channels being in one-to-one correspondence with the openings of the plurality of whistle holes.

16. The pressure relief valve of claim 15, wherein, The flow dividing part comprises a plurality of flow dividing plates arranged along the circumference of the valve body, and two adjacent flow dividing plates and the inner circumferential surface of the second hole section form the flow channel.

17. The pressure relief valve of claim 16, wherein, The flow distribution plate extends from an end of the second hole section proximate to the first hole section toward the outlet.

18. The pressure relief valve of any one of claims 1 to 17, wherein, The pressure relief hole includes opposite inlet and outlet, and the pressure relief valve further includes a clamping portion protruding from an end face of an end of the valve body provided with the inlet, and the clamping portion is configured to be clamped with the shell of the battery pack.

19. The pressure relief valve of any one of claims 1 to 17, wherein, The pressure relief hole includes opposite inlet and outlet, and the pressure relief valve further includes a sealing member provided at an end of the valve body provided with the inlet, and the sealing member is configured to seal the gap between the valve body and the shell of the battery pack. 20.A battery pack, comprising: a shell including a cavity; a battery module provided in the cavity; a pressure relief valve according to any one of claims 1 to 19, the pressure relief valve being connected with the shell, and the pressure relief hole of the pressure relief valve being configured to communicate the cavity and the outside of the shell.

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