Pressure relief device, cell, and battery pack

Abstract

The utility model provides a kind of pressure relief device, battery cell and battery pack, the pressure relief device includes body, positioning member and moving piece. Among them, pressure relief cavity is provided in body, and first pressure relief port that pressure relief cavity is also provided with the conduction with outside on body;Positioning member is at least partially set in pressure relief cavity, and positioning member is provided with conveying channel on it, the part of positioning member in pressure relief cavity is provided with second pressure relief port, and one end of conveying channel extends to the outside of body;Moving piece is movably set in conveying channel, and moving piece has first position that moves to stop second pressure relief port to make conveying channel and pressure relief cavity isolated, and moving piece also has second position that moves to avoid second pressure relief port to make conveying channel and pressure relief cavity communicate.The pressure relief device, battery cell and battery pack of the utility model improve the technical problem that battery cell is deformed and cannot be matched with battery pack structure.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a pressure relief device, a battery cell, and a battery pack. Background Technology

[0002] In related technologies, although the battery cell is equipped with an explosion-proof valve to relieve pressure in the event of thermal runaway, the pressure required to open the explosion-proof valve is too high, making it impossible to relieve pressure on the battery cell when the internal pressure is low. This causes the battery cell to deform and become incompatible with the corresponding battery pack structure. Utility Model Content

[0003] The embodiments of this utility model provide a pressure relief device, a battery cell, and a battery pack, which can improve the technical problem of battery cell deformation that makes it impossible to match the battery pack structure.

[0004] In a first aspect, embodiments of the present invention provide a pressure relief device, comprising:

[0005] The body has a pressure relief chamber inside and a first pressure relief port that connects the pressure relief chamber to the outside. With this configuration, when there is gas in the pressure relief chamber, the gas in the pressure relief chamber can be guided to the outside of the pressure relief chamber from the first pressure relief port.

[0006] A positioning element is provided, at least partially disposed in the pressure relief chamber, and a conveying channel is provided on the positioning element. The portion of the positioning element located inside the pressure relief chamber is provided with a second pressure relief port, and one end of the conveying channel extends to the outside of the main body. With this configuration, when the second pressure relief port connects the conveying channel and the pressure relief chamber, and there is gas in the conveying channel, the gas in the conveying channel can be guided to the pressure relief chamber through the second pressure relief port.

[0007] A movable component is movably disposed in the conveying channel, and the movable component has a first position where it moves to block the second pressure relief port to isolate the conveying channel from the pressure relief chamber, and a second position where it moves to avoid the second pressure relief port to connect the conveying channel with the pressure relief chamber. This arrangement allows the movable component to open or close the second pressure relief port, thereby controlling the connection or blockage between the conveying channel and the pressure relief chamber.

[0008] In some embodiments, the movable member includes a movable body and a stop flange disposed on the movable body. The movable body is movably inserted into the conveying channel to switch between a first position and a second position. The stop flange is configured to stop at the end of the conveying channel when the movable member is in the first position. This configuration allows the movable body to have a defined travel distance and facilitates the movable body to open or close the conveying channel and the pressure relief chamber.

[0009] In some embodiments, the pressure relief device further includes an elastic element, the two ends of which abut against the inner wall surface of the pressure relief cavity and the stop flange, respectively;

[0010] The elastic element is configured to be compressed when the pressure in the conveying channel is greater than or equal to a preset value, thereby causing the moving element to switch from the first position to the second position.

[0011] The elastic element is also configured to automatically reset when the pressure in the conveying channel is less than the preset value, thereby switching the moving element from the second position to the first position. This configuration can both prevent the moving element from being subjected to excessive impact and ensure that the moving element automatically resets when the pressure in the conveying channel is less than the preset value.

[0012] In some embodiments, the positioning element includes a positioning sleeve, the positioning sleeve includes a first sleeve segment and a second sleeve segment connected to the first sleeve segment, the cross-sectional area of ​​the first sleeve segment is larger than the cross-sectional area of ​​the second sleeve segment, a limiting step is provided at the connection between the first sleeve segment and the second sleeve segment, the second sleeve segment extends to the outside of the main body, and the conveying channel and the second pressure relief port are both provided in the second sleeve segment;

[0013] When the moving part is in the first position, the stop flange stops at the limiting step; this arrangement allows the cooperation between the stop flange and the end of the conveying channel to provide a clear position for the moving body, thereby enabling the pressure relief device to precisely control the second pressure relief port to switch between the first position and the second position.

[0014] In some embodiments, the first pressure relief port includes at least one, such that when there are multiple first pressure relief ports, if one of the first pressure relief ports is blocked, the other first pressure relief ports can still function; and / or,

[0015] The second pressure relief port includes at least one; thus, when there are multiple second pressure relief ports, if one of the second pressure relief ports is blocked, the other second pressure relief ports can still function.

[0016] In some embodiments, the sum of the flow areas of all the first pressure relief ports is greater than or equal to the sum of the flow areas of all the second pressure relief ports; this arrangement enables the first pressure relief ports to promptly guide the gas ejected from the second pressure relief ports to the outside of the pressure relief device.

[0017] In some embodiments, when there are multiple first pressure relief ports, the multiple first pressure relief ports are spaced apart along the same circumferential direction. This arrangement can avoid damage to the pressure relief chamber caused by concentrated gas pressure; and / or,

[0018] When there are multiple second pressure relief ports, the multiple second pressure relief ports are arranged at intervals along the circumference of the conveying channel. This arrangement can avoid damage to the conveying channel caused by concentrated gas pressure.

[0019] In some embodiments, the pressure relief chamber includes a first sidewall and a second sidewall disposed opposite to each other, the delivery channel extends from the first sidewall to the outside of the body, and the first pressure relief port is disposed on the second sidewall; this arrangement allows a clear and relatively long pressure relief path to be formed within the pressure relief device, thereby reducing the gas flow rate and minimizing the impact of the gas.

[0020] In some embodiments, the second pressure relief port extends radially along the conveying channel. This arrangement ensures that the gas ejected from the second pressure relief port must make a bend before exiting the first pressure relief port, thereby reducing the gas flow rate and minimizing the impact of the gas; or,

[0021] Along the inner and outer directions of the conveying channel, the second pressure relief port is inclined towards the first sidewall; this configuration, compared to the second pressure relief port extending in the radial direction of the conveying channel, can further reduce the gas flow rate and reduce the impact of the gas.

[0022] In some embodiments, the body is provided with a connecting portion located on the side of the body opposite to the first pressure relief port, for at least connecting the body to a predetermined structure; thus, the pressure relief device can be connected to the predetermined structure through the connecting portion, thereby enabling the pressure relief device to perform its pressure relief function.

[0023] Secondly, embodiments of this utility model provide a battery cell, which includes the aforementioned pressure relief device and pressure relief valve. The pressure relief device and the pressure relief valve are spaced apart at the same end of the battery cell, and the delivery channel communicates with the interior of the battery cell. This arrangement allows the pressure relief device to relieve pressure on the battery cell, thereby preventing the battery cell from undergoing severe deformation and becoming unsuitable for the battery pack's casing or other structures. The pressure relief valve can relieve pressure on the battery cell when thermal runaway occurs, preventing excessive damage caused by thermal runaway. The dual pressure relief provided by the pressure relief device and the pressure relief valve further enhances the reliability of the battery cell.

[0024] In some embodiments, the battery cell includes at least one of the pressure relief devices. When there are multiple pressure relief devices, the multiple pressure relief devices are spaced apart on opposite sides of the pressure relief valve. In this configuration, when the battery cell includes multiple pressure relief devices, if one of the pressure relief devices is damaged, the other pressure relief devices can still function.

[0025] Thirdly, embodiments of this utility model provide a battery pack in which the aforementioned battery cells are configured such that the battery cells equipped with the pressure relief device and the pressure relief valve can be matched with the battery pack's housing and other structures, facilitating the assembly of the battery pack.

[0026] In embodiments of this invention, the movable component is movable within the conveying channel and has a first position and a second position. During actual operation, when the pressure relief device is not required to depressurize the battery cell, the movable component is in the first position. At this time, the movable component blocks the second pressure relief port, isolating the conveying channel from the pressure relief chamber. When gas is generated inside the battery cell, the gas can contact the end of the movable component closest to the battery cell via the conveying channel. As the gas increases, the movable component gradually moves away from the battery cell under the pressure generated by the gas, causing it to change from the first position to the second position. At this time, the movable component avoids the location of the second pressure relief port, allowing the conveying channel to connect with the pressure relief chamber. The gas inside the battery cell can then flow through the conveying channel to the second pressure relief port, and then flow into the pressure relief chamber through the second pressure relief port, finally being discharged to the outside of the battery cell through the first pressure relief port, thereby achieving the effect of depressurizing the battery cell, preventing severe deformation of the battery cell, and allowing the battery cell to be matched with the battery pack casing and other structures. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a perspective view of the battery pack provided in an embodiment of the present invention;

[0029] Figure 2 This is a three-dimensional schematic diagram of the battery cell provided in an embodiment of this utility model;

[0030] Figure 3 This is a schematic diagram of the battery cell provided in an embodiment of the present invention from a first-view perspective;

[0031] Figure 4 This is a schematic diagram of the battery cell provided in an embodiment of the present invention from a second perspective;

[0032] Figure 5 This is an exploded view of the battery cell provided in an embodiment of this utility model;

[0033] Figure 6 This is a cross-sectional view of the battery cell provided in an embodiment of the present invention from a third-person perspective;

[0034] Figure 7 for Figure 6 Enlarged view of section A;

[0035] Figure 8 This is a perspective view of the pressure relief device provided in an embodiment of the present invention from a fourth-person perspective.

[0036] Figure 9 This is a three-dimensional schematic diagram of the pressure relief device provided in an embodiment of this utility model from a fifth-angle perspective;

[0037] Figure 10 This is a schematic diagram of the pressure relief device provided in an embodiment of the present invention from a first-view perspective;

[0038] Figure 11 This is a schematic diagram of the pressure relief device provided in an embodiment of the present invention from a third-person perspective.

[0039] 100. Pressure relief device; 10. Body; 11. Pressure relief chamber; 111. First side wall; 112. Second side wall; 12. First pressure relief port; 13. Connecting part; 20. Positioning component; 21. Conveying channel; 22. Second pressure relief port; 23. Positioning sleeve; 231. First body segment; 232. Second body segment; 233. Limiting step; 30. Moving component; 31. Moving main body; 32. Stop flange; 40. Elastic component; 200. Battery cell; 210. Pressure relief valve; 220. Positive electrode; 230. Negative electrode; 240. Mounting hole; 300. Battery pack; 310. Housing. Detailed Implementation

[0040] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0041] As mentioned in the background section, in related technologies, although the battery cell is equipped with an explosion-proof valve to relieve pressure in the event of thermal runaway, the pressure required to open the explosion-proof valve is too high, making it impossible to relieve pressure on the battery cell when the internal pressure is low. This results in the battery cell deforming and becoming incompatible with the corresponding battery pack structure.

[0042] To address the problems existing in the relevant technologies, see [link to relevant documentation]. Figure 1 and Figure 2As shown, this utility model provides a battery pack 300, which includes a battery cell 200 and a housing 310. The battery cell 200 includes a pressure relief device 100 and a pressure relief valve 210, which are spaced apart and disposed at the same end of the battery cell 200. Thus, when the internal air pressure of the battery cell 200 is insufficient to open the pressure relief valve 210, the pressure relief device 100 can be opened by the internal air pressure of the battery cell 200. This relieves pressure on the battery cell 200, preventing severe deformation of the battery cell and allowing the battery cell 200 to better match the structure of the battery pack 300, such as the housing 310. To prevent the pressure relief device 100 from malfunctioning and failing to relieve pressure on the battery cell 200 in a timely manner, the battery cell 200 of this application includes at least one pressure relief device 100. When there are multiple pressure relief devices 100, they are spaced apart and disposed on opposite sides of the pressure relief valve 210. Thus, when one of the pressure relief devices 100 on the battery cell 200 malfunctions and cannot function properly, the other pressure relief devices 100 on the battery cell 200 can still continue to function, thereby preventing the battery cell 200 from undergoing severe deformation and becoming unable to match the structure of the battery pack 300, such as the casing 310. The aforementioned pressure relief device 100 includes a body 10, a positioning member 20, and a moving member 30. The main body 10 is provided with a pressure relief chamber 11, and the main body 10 is also provided with a first pressure relief port 12 that connects the pressure relief chamber 11 to the outside. The positioning member 20 is at least partially disposed in the pressure relief chamber 11, and the positioning member 20 is provided with a conveying channel 21. The portion of the positioning member 20 located in the pressure relief chamber 11 is provided with a second pressure relief port 22. One end of the conveying channel 21 extends to the outside of the main body 10. The moving member 30 is movably disposed in the conveying channel 21. The moving member 30 has a first position where it moves to stop the second pressure relief port 22 to isolate the conveying channel 21 from the pressure relief chamber 11. The moving member 30 also has a second position where it moves to avoid the second pressure relief port 22 to connect the conveying channel 21 with the pressure relief chamber 11.

[0043] In this application, the movable component 30 is movable within the conveying channel 21, and the movable component 30 has a first position and a second position. During actual operation, when the pressure relief device 100 is not required to depressurize the battery cell 200, the movable component 30 is in the first position. At this time, the movable component 30 blocks the second pressure relief port 22, isolating the conveying channel 21 from the pressure relief chamber 11. When gas is generated inside the battery cell 200, the gas can contact the end of the movable component 30 near the battery cell 200 along the conveying channel 21. As the gas increases, the movable component 30 gradually moves away from the battery cell 200 under the pressure generated by the gas, causing the movable component 30 to change from the first position to the second position. At this time, the movable component 30 avoids the position of the second pressure relief port 22, allowing the conveying channel 21 to connect with the pressure relief chamber 11. The gas inside the cell 200 can flow through the delivery channel 21 to the second pressure relief port 22, and then flow into the pressure relief chamber 11 through the second pressure relief port 22. Finally, it is discharged to the outside of the cell 200 through the first pressure relief port 12, thereby achieving the effect of relieving pressure on the cell 200, preventing the cell 200 from undergoing severe deformation, and thus enabling the cell 200 to be matched with the structure such as the casing 310 of the battery pack 300.

[0044] In other words, compared with the existing battery cell 200, the battery cell 200 of this application is equipped with a pressure relief device 100 in addition to a pressure relief valve 210 to relieve pressure on the battery cell 200, thereby preventing the battery cell 200 from undergoing severe deformation and failing to match the structure such as the casing 310 of the battery pack 300.

[0045] It is understood that when the pressure relief device 100 of this application is installed on the battery cell 200, the delivery channel 21 of the battery cell 200 needs to be connected to the inside of the battery cell 200 so that the gas inside the battery cell 200 can be discharged to the outside of the battery cell 200 through the delivery channel 21 and the pressure relief device 100.

[0046] In some embodiments, see Figure 2 , Figure 6 as well as Figure 7 As shown, the moving part 30 includes a moving body 31 and a stop flange 32 disposed on the moving body 31. The moving body 31 is movably inserted into the conveying channel 21 to switch between a first position and a second position. The stop flange 32 is configured to stop at the end of the conveying channel 21 when the moving part 30 is in the first position.

[0047] Specifically, the stop flange 32 is disposed on the moving body 31. When the moving part 30 is in the first position, the stop flange 32 precisely stops at the end of the conveying channel 21, effectively isolating the conveying channel 21 from the pressure relief chamber 11. This design ensures that the pressure inside the battery cell 200 remains stable when pressure relief is not required, and will not leak through the pressure relief device 100. The moving body 31 is movable within the conveying channel 21, and combined with the stopping effect of the stop flange 32, it enables precise switching of the moving part 30 between the first and second positions. The cooperation between the stop flange 32 and the end of the conveying channel 21 provides a clear position for the moving body 31, allowing the pressure relief device 100 to accurately open and close itself through the gas inside the battery cell 200. The moving body 31 is inserted into the conveying channel 21, and this cooperation provides a stable guide for the movement of the moving part 30, ensuring that the moving body 31 will not deviate during movement. The precise pressure relief control function enables the pressure relief device 100 to accurately perform pressure relief operations based on the magnitude of the gas pressure inside the battery cell 200.

[0048] In some embodiments, see Figure 2 , Figure 6 as well as Figure 7 As shown, the pressure relief device 100 also includes an elastic element 40, with both ends of the elastic element 40 abutting against the inner wall surface of the pressure relief chamber 11 and the stop flange 32 respectively; wherein, the elastic element 40 is configured to be compressed when the pressure in the conveying channel 21 is greater than or equal to a preset value, thereby causing the moving element 30 to switch from the first position to the second position; the elastic element 40 is also configured to automatically reset when the pressure in the conveying channel 21 is less than the preset value, thereby causing the moving element 30 to switch from the second position to the first position.

[0049] Specifically, the two ends of the elastic element 40 abut against the inner wall of the pressure relief chamber 11 and the stop flange 32, respectively. When the pressure in the delivery channel 21 is greater than or equal to a preset value, the elastic element 40 is compressed, pushing the moving element 30 from the first position to the second position. At this time, the delivery channel 21 and the pressure relief chamber 11 are connected by the second pressure relief port 22. This allows the pressure relief device 100 to automatically respond to pressure changes in the battery cell 200 and initiate the pressure relief operation without manual intervention. When the pressure in the delivery channel 21 is less than the preset value, the elastic element 40 automatically resets, causing the moving element 30 to switch from the second position back to the first position. At this time, the second pressure relief port 22 is stopped by the moving element 30, the connection between the delivery channel 21 and the pressure relief chamber 11 is blocked, and the pressure relief device 100 stops depressurizing the battery cell 200. This automatic reset function ensures that the pressure relief device 100 closes promptly after the pressure inside the cell 200 returns to normal, thus preventing excessive pressure drop from negatively impacting the cell 200 and preventing external dust and other impurities from entering the cell 200. Furthermore, by setting the elastic parameters of the elastic element 40, the pressure thresholds for triggering and stopping pressure relief (i.e., preset values) can be precisely set, and these preset values ​​can be adjusted according to the pressure requirements of different cells 200, ensuring that the pressure relief device 100 starts or stops pressure relief at the most suitable pressure point. In addition, the elastic buffering effect of the elastic element 40 allows the moving element 30 to switch positions more smoothly, avoiding instability in the pressure relief process caused by instantaneous pressure changes. As the pressure gradually increases and approaches the preset value, the elastic element 40 is gradually compressed, and the moving element 30 gradually avoids the second pressure relief port 22, allowing the transmission channel 21 and the pressure relief chamber 11 to be connected, thus enabling the pressure relief process to proceed smoothly. When the pressure decreases, the elastic element 40 gradually resets, and the moving element 30 gradually stops the second pressure relief port 22, gradually cutting off the connection between the transmission channel 21 and the pressure relief chamber 11, effectively reducing pressure fluctuations and achieving stable pressure relief of the internal pressure of the battery cell 200.

[0050] In some embodiments, see Figure 2 , Figure 6 as well as Figure 7 As shown, the positioning component 20 includes a positioning sleeve 23, which includes a first body segment 231 and a second body segment 232 connected to the first body segment 231. The cross-sectional area of ​​the first body segment 231 is larger than that of the second body segment 232. The connection between the first body segment 231 and the second body segment 232 has a limiting step 233. The second body segment 232 extends to the outside of the body 10. The conveying channel 21 and the second pressure relief port 22 are both located in the second body segment 232. When the moving component 30 is in the first position, the stop flange 32 stops at the limiting step 233.

[0051] Specifically, the cross-sectional area of ​​the first segment 231 of the positioning sleeve 23 (i.e., the cross-sectional area of ​​the channel inside the first segment 231 when it is laterally cut) is larger than the cross-sectional area of ​​the second segment 232 (i.e., the cross-sectional area of ​​the channel inside the second segment 232 when it is laterally cut), and a limiting step 233 is formed at the junction of the two. When the moving part 30 is in the first position, the stop flange 32 stops at the limiting step 233, which provides precise positioning for the moving part 30. This design ensures that the moving part 30 can accurately stop the second pressure relief port 22 every time it is in the first position, forming a reliable isolation between the conveying channel 21 and the pressure relief chamber 11, effectively preventing gas leakage inside the battery cell 200. The stopping effect of the limiting step 233 on the moving part 30 gives the moving part 30 a clear travel limit during movement, reducing unnecessary friction and collision between the moving part 30 and other components. When the moving part 30 moves within the conveying channel 21, it will not collide with other parts due to excessive movement, thereby extending the service life of the moving part 30, the positioning sleeve 23, and the entire pressure relief device 100. The structural design of the positioning sleeve 23 makes its installation process relatively simple. The second body segment 232 extends to the outside of the main body 10. This design ensures that when the pressure relief device 100 is installed on the battery cell 200, it is easy for the second body segment 232 to extend into the interior of the battery cell 200 for connection. Through precise positioning and sealing design, the pressure relief device 100 can accurately control the pressure relief process. The conveying channel 21 and the pressure relief chamber 11 will only connect for pressure relief when the moving part 30 moves to the second position, while it can be reliably isolated in the first position, ensuring the accuracy and reliability of the pressure relief operation.

[0052] In some embodiments, see Figure 7 , Figure 8 as well as Figure 10 As shown, the first pressure relief port 12 includes at least one. Specifically, the number of first pressure relief ports 12 can be reasonably adjusted according to actual conditions and needs, and this application does not impose specific limitations. When there are multiple first pressure relief ports 12, the multiple first pressure relief ports 12 are spaced apart along the circumferential direction of the body 10 at one end of the body 10 away from the second set of body segments 232. This embodiment shows the case where there are two first pressure relief ports 12, and the two first pressure relief ports 12 are evenly spaced apart on the body 10.

[0053] Optionally, the second pressure relief port 22 includes at least one. Specifically, the number of second pressure relief ports 22 can be reasonably adjusted according to actual conditions and needs, and this application does not impose specific limitations. When there are multiple second pressure relief ports 22, the multiple second pressure relief ports 22 are spaced apart along the outer periphery of the second sleeve segment 232. This embodiment shows the case where there are two second pressure relief ports 22, and the two second pressure relief ports 22 are evenly spaced apart on the outer periphery of the second sleeve segment 232. In addition, the distance between the second pressure relief port 22 and the bottom of the pressure relief cavity 11 (i.e., the bottom surface inside the pressure relief cavity 11) can be reasonably adjusted according to actual conditions, and this application does not impose specific limitations. Figure 7 As shown in the figure, this embodiment illustrates a case where the distance between the lower edge of the second pressure relief port 22 and the bottom of the pressure relief chamber 11 is 0.3 mm.

[0054] In some embodiments, see Figure 7 , Figure 8 as well as Figure 10 As shown, the sum of the flow areas of all first pressure relief ports 12 is greater than or equal to the sum of the flow areas of all second pressure relief ports 22.

[0055] Specifically, the flow area mentioned in this application refers to the cross-sectional area obtained by cutting the airflow (i.e., the gas flow formed when the gas flows) in a direction perpendicular to the gas flow direction (i.e., the extension direction of the first pressure relief port 12 or the second pressure relief port 22) when the gas flows through the first pressure relief port 12 or the second pressure relief port 22. The sum of the flow areas of all the first pressure relief ports 12 is greater than or equal to the sum of the flow areas of all the second pressure relief ports 22. This ensures that during the pressure relief process, the first pressure relief port 12 can promptly discharge the gas discharged from the second pressure relief port 22 into the pressure relief chamber 11 to the outside of the pressure relief chamber 11, ensuring smooth pressure relief. When the moving part 30 is in the second position and the conveying channel 21 is connected to the pressure relief chamber 11 for pressure relief, the sufficiently large flow area of ​​the first pressure relief port 12 can quickly release the pressure inside the cell 200. The larger flow area of ​​the first pressure relief port 12 helps to prevent pressure from accumulating in the pressure relief chamber 11 during the pressure relief process. If the flow area of ​​the first pressure relief port 12 is too small, it may cause poor gas discharge from the pressure relief chamber 11. Even if the second pressure relief port 22 is open, the pressure generated by the gas cannot be released in time, thus affecting the pressure relief effect of the pressure relief device 100 on the battery cell 200. A sufficiently large flow area of ​​the first pressure relief port 12 allows pressure to be discharged smoothly, maintaining the pressure in the pressure relief chamber 11 at a low level, ensuring that the pressure relief device 100 can work continuously and effectively. Figure 7 and Figure 10As shown in the figure, this embodiment illustrates a case where there are two first pressure relief ports 12 and two second pressure relief ports 22, and the diameter of both the first pressure relief ports 12 and the second pressure relief ports 22 is 0.8 mm. That is, this embodiment shows a case where the sum of the flow areas of all the first pressure relief ports 12 is equal to the sum of the flow areas of all the second pressure relief ports 22.

[0056] In some embodiments, see Figure 7 , Figure 8 as well as Figure 10 As shown, when there are multiple first pressure relief ports 12, they are spaced apart along the same circumferential direction. Specifically, when there are multiple first pressure relief ports 12 and they are spaced apart along the same circumferential direction, the pressure can be uniformly released from different positions of the pressure relief chamber 11 to the outside of the pressure relief chamber 11. The uniform pressure relief method can prevent pressure imbalance caused by uneven pressure release. If the first pressure relief ports 12 are concentrated on one side of the pressure relief device 100, the pressure on one side of the pressure relief device 100 will be too high during pressure relief. The pressure concentration makes the pressure relief device 100 easily damaged by the impact of gas pressure. Therefore, when there are multiple first pressure relief ports 12, this application adopts the method of multiple first pressure relief ports 12 spaced apart along the same circumferential direction, which can improve the service life of the pressure relief device 100.

[0057] Optionally, when there are multiple second pressure relief ports 22, the multiple second pressure relief ports 22 are arranged at intervals along the circumference of the conveying channel 21. Specifically, when there are multiple second pressure relief ports 22 and they are arranged at intervals along the circumference of the conveying channel 21, the pressure can be evenly released from different positions of the conveying channel 21 into the pressure relief chamber 11. The uniform pressure relief method can prevent pressure imbalance caused by uneven pressure release. If the second pressure relief ports 22 are concentrated on one side, the pressure on one side of the pressure relief device 100 will be too high during pressure relief, and the pressure concentration will make the pressure relief device 100 easily damaged by the impact of gas pressure. Therefore, when there are multiple second pressure relief ports 22, this application adopts the method of arranging multiple second pressure relief ports 22 at intervals along the same circumferential direction, which can improve the service life of the pressure relief device 100.

[0058] In some embodiments, see Figures 7 to 9 As shown, the pressure relief chamber 11 includes a first sidewall 111 and a second sidewall 112 disposed opposite to each other. The conveying channel 21 extends from the first sidewall 111 to the outside of the body 10, and the first pressure relief port 12 is disposed on the second sidewall 112.

[0059] Specifically, in the pressure relief chamber 11, the delivery channel 21 extends from the first side wall 111, while the first pressure relief port 12 is located on the second side wall 112 opposite to the first side wall 111. This design allows for a clear and relatively long pressure relief path within the pressure relief device 100. When pressure relief is required for the battery cell 200, the gas inside the battery cell 200 enters the pressure relief chamber 11 through the delivery channel 21 and then needs to travel a certain distance before being discharged from the first pressure relief port 12. This process helps to buffer and disperse the pressure within the pressure relief chamber 11, preventing excessive impact on the pressure relief device 100 caused by a sudden concentrated release of pressure. This makes the pressure relief process more stable, and a stable pressure relief process can prevent impact and damage to other components within the pressure relief device 100 caused by sudden pressure changes. At the same time, the relatively long pressure relief path and reasonable layout effectively increase the flow space and time of the gas within the pressure relief chamber 11. This facilitates more complete diffusion of the gas within the pressure relief chamber 11, allowing it to be discharged more efficiently to the outside of the pressure relief chamber 11 through the first pressure relief port 12.

[0060] In some embodiments, see 6 and Figure 7 As shown, the second pressure relief port 22 extends radially along the conveying channel 21; or along the inner and outer directions of the conveying channel 21, the second pressure relief port 22 is inclined toward the first sidewall 111.

[0061] Specifically, when the second pressure relief port 22 extends radially along the conveying channel 21, the gas ejected from the second pressure relief port 22 can make a first bend within the conveying channel 21 and then be directly ejected radially towards the side wall of the pressure relief chamber 11. Furthermore, since the first pressure relief port 12 is located on the second side wall 112 of the pressure relief chamber 11 (i.e., the top of the pressure relief chamber 11), the gas in the pressure relief chamber 11 makes a second bend within the pressure relief chamber 11 before being ejected from the first pressure relief port 12 to the outside of the pressure relief chamber 11. This allows the gas to be sufficiently decelerated within the bend in the exhaust channel formed by the conveying channel 21, the second pressure relief port 22, the pressure relief chamber 11, and the first pressure relief port 12, thereby reducing the velocity of the ejected gas and minimizing the impact generated by the gas. When the second pressure relief port 22 is inclined towards the first sidewall 111 along the inward and outward directions of the conveying channel 21, the gas ejected from the second pressure relief port 22 can be ejected towards the first sidewall 111 (i.e., the bottom of the pressure relief chamber 11) of the pressure relief chamber 11 after making a first bend within the conveying channel 21. Since the first pressure relief port 12 is located on the second sidewall 112 of the pressure relief chamber 11, the gas in the pressure relief chamber 11 makes a second bend within the pressure relief chamber 11 before being ejected from the first pressure relief port 12 to the outside of the pressure relief chamber 11. This allows the gas to be sufficiently decelerated within the bend in the exhaust channel formed by the conveying channel 21, the second pressure relief port 22, the pressure relief chamber 11, and the first pressure relief port 12, thereby reducing the speed of the ejected gas and minimizing the impact generated by the gas. Compared to the second pressure relief port 22 extending radially along the conveying channel 21, the inclination of the second pressure relief port 22 towards the first sidewall 111 further decelerates the gas, resulting in a smaller impact from the gas ejected from the first pressure relief port 12. For example... Figure 7 As shown in the figure, this embodiment illustrates the case where the second pressure relief port 22 extends radially along the conveying channel 21. Furthermore, the bent exhaust channel formed by the conveying channel 21, the second pressure relief port 22, the pressure relief chamber 11, and the first pressure relief port 12 can also block any electrolyte that may be carried in the gas ejected from the second pressure relief port 22 within the pressure relief chamber 11, preventing the electrolyte from being ejected and affecting the external electrical insulation of the battery cell 200.

[0062] In some embodiments, see 5. Figure 7 as well as Figure 9 As shown, a connecting part 13 is provided on the main body 10. The connecting part 13 is located on the side of the main body 10 away from the first pressure relief port 12, so as to at least connect the main body 10 to a predetermined structure.

[0063] Specifically, the connecting part 13 is located on the side of the main body 10 away from the first pressure relief port 12, so that the pressure relief device 100 can be easily connected to a predetermined structure such as the battery cell 200. For ease of introduction of the pressure relief device 100, this embodiment mainly describes the case when the pressure relief device 100 is installed on the battery cell 200. When the pressure relief device 100 is installed on the battery cell 200, a mounting hole 240 is provided at the corresponding mounting position on the battery cell 200 to match the connecting part 13. The connecting part 13 can be a threaded connection structure. Correspondingly, if the connecting part 13 is a threaded structure, a corresponding thread will also be provided at the mounting hole 240 to match the thread of the connecting part 13, thereby ensuring the reliability of the connection between the pressure relief device 100 and the battery cell 200. Meanwhile, in order to ensure that gas does not leak from the connection between the pressure relief device 100 and the battery cell 200 after the pressure relief device 100 is installed on the battery cell 200, a sealing ring (not shown in the figure) can be provided between the connection part 13 and the mounting hole 240 to enhance the sealing performance. At the same time, the pressure relief device 100 and the battery cell 200 can also be sealed by welding. This embodiment shows the case where the connection part 13 and the mounting hole 240 are connected and the pressure relief device 100 and the battery cell 200 are sealed by welding.

[0064] In some embodiments, see Figures 9 to 11 As shown, the shape and size of the body 10 can be reasonably adjusted as needed, and this application does not impose specific limitations. This embodiment shows the case where the body 10 is cylindrical. In addition, this embodiment shows the case where the diameter of the cylindrical body 10 is 10 mm and the length (here, the length including the length of the conveying channel 21 extending to the outside of the body 10) is 10.5 mm.

[0065] In some embodiments, see Figure 1 , Figure 3 as well as Figure 4As shown, the shape and size of the battery cell 200 can be reasonably adjusted according to actual conditions and needs, and this application does not impose specific limitations. This embodiment shows that the battery cell 200 is approximately rectangular, and this embodiment shows that the length of the rectangular prism is 173.7 mm, the width is 71.7 mm, and the height is 204.3 mm. In this embodiment, when the pressure relief device 100 is installed on the battery cell 200, the distance between the top of the pressure relief device 100 and the upper end face of the battery cell 200 (i.e., the end face of the battery cell 200 used to install the pressure relief device 100) is 7 mm. In addition, the battery cell 200 of this application is also provided with a positive electrode 220 and a negative electrode 230 for charging and discharging the battery cell 200. The pressure relief device 100 and the pressure relief valve 210 are spaced apart between the positive electrode 220 and the negative electrode 230. The pressure relief device 100 is mainly used to relieve pressure on the battery cell 200 to prevent the battery cell 200 from undergoing severe deformation and becoming unable to match the structure such as the casing 310 of the battery pack 300. The pressure relief valve 210 is mainly used to relieve pressure on the battery cell 200 when thermal runaway occurs, to prevent excessive damage caused by thermal runaway of the battery cell 200.

[0066] In summary, the pressure relief device, battery cell, and battery pack of this application have at least the following beneficial effects:

[0067] (1) By setting pressure relief devices and pressure relief valves at intervals at the same end of the cell, the pressure relief devices can be opened to relieve pressure when the air pressure inside the cell is low, preventing the cell from deforming violently and ensuring that the cell can match the structure of the battery pack, such as the casing.

[0068] (2) The battery cell includes at least one pressure relief device. When there are multiple pressure relief devices, the multiple pressure relief devices are spaced apart on both sides of the pressure relief valve to avoid the failure of a single pressure relief device, which would prevent the battery cell from being unable to be depressurized and further improve the reliability of the battery cell.

[0069] (3) The moving parts in the pressure relief device can be switched by air pressure in the conveying channel, and the pressure relief can be opened and closed without manual intervention. It is not only simple in structure, but also responds in a timely manner.

[0070] (4) The elastic element can automatically compress or reset according to the pressure. The pressure relief threshold of the pressure relief device can be set by adjusting the elastic parameter of the elastic element. The buffering effect of the elastic element can make the pressure relief process more stable, reduce pressure fluctuations, and prevent external impurities from entering the inside of the battery cell.

[0071] (5) The positioning sleeve's limiting step can accurately position the moving parts, ensuring that the moving parts can accurately stop or avoid the pressure relief port, reducing friction and collision between parts, and extending the service life of the pressure relief device.

[0072] (6) The number of the first pressure relief port and the second pressure relief port can be flexibly adjusted, and the total flow area of ​​the first pressure relief port and the total flow area of ​​the second pressure relief port are reasonable, which can prevent pressure from accumulating in the pressure relief device, thereby ensuring uniform pressure relief, and thus reducing the impact on the pressure relief device and extending the service life of the pressure relief device.

[0073] (7) A long pressure relief path is formed inside the pressure relief device, which allows the gas to be buffered and dispersed when it flows inside the pressure relief device, avoiding instantaneous pressure release and protecting the internal components of the pressure relief device.

[0074] (8) The second pressure relief port extends radially or is inclined to form a bent exhaust channel, which can effectively decelerate the gas and reduce the impact when the gas is ejected.

[0075] (9) The connection part of the body is easy to connect with the battery cell. With the help of the sealing ring or welding, the sealing performance is enhanced, which can prevent gas leakage and ensure that the pressure relief device is firmly connected to the battery cell.

[0076] (10) The pressure relief device is responsible for low-pressure pressure relief and deformation prevention, while the pressure relief valve is responsible for thermal runaway pressure relief. The two have a clear division of labor, which improves the overall safety and structural compatibility of the battery pack.

[0077] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A pressure relief device (100), characterized in that, include: The body (10) has a pressure relief chamber (11) inside and a first pressure relief port (12) that connects the pressure relief chamber (11) to the outside. Positioning element (20), the positioning element (20) is at least partially disposed in the pressure relief chamber (11), and the positioning element (20) is provided with a conveying channel (21), the portion of the positioning element (20) located in the pressure relief chamber (11) is provided with a second pressure relief port (22), and one end of the conveying channel (21) extends to the outside of the body (10); A movable member (30) is movably disposed in the conveying channel (21), and the movable member (30) has a first position to move to stop the second pressure relief port (22) so that the conveying channel (21) is isolated from the pressure relief chamber (11), and the movable member (30) also has a second position to move to avoid the second pressure relief port (22) so that the conveying channel (21) is connected to the pressure relief chamber (11).

2. The pressure relief device (100) according to claim 1, characterized in that, The moving part (30) includes a moving body (31) and a stop flange (32) disposed on the moving body (31). The moving body (31) is movably inserted into the conveying channel (21) to switch between a first position and a second position. The stop flange (32) is configured to stop at the end of the conveying channel (21) when the moving part (30) is in the first position.

3. The pressure relief device (100) according to claim 2, characterized in that, The pressure relief device (100) further includes an elastic element (40), the two ends of which abut against the inner wall surface of the pressure relief cavity (11) and the stop flange (32); The elastic element (40) is configured to be compressed when the pressure in the conveying channel (21) is greater than or equal to a preset value, thereby causing the moving element (30) to switch from the first position to the second position. The elastic element (40) is also configured to automatically reset when the pressure in the conveying channel (21) is less than the preset value, thereby switching the moving element (30) from the second position to the first position.

4. The pressure relief device (100) according to claim 2, characterized in that, The positioning component (20) includes a positioning sleeve (23), which includes a first body segment (231) and a second body segment (232) connected to the first body segment (231). The cross-sectional area of ​​the first body segment (231) is larger than that of the second body segment (232). The connection between the first body segment (231) and the second body segment (232) has a limiting step (233). The second body segment (232) extends to the outside of the body (10). The conveying channel (21) and the second pressure relief port (22) are both located in the second body segment (232). When the movable member (30) is in the first position, the stop flange (32) stops at the limiting step (233).

5. The pressure relief device (100) according to claim 1, characterized in that, The first pressure relief port (12) includes at least one; and / or, The second pressure relief port (22) includes at least one.

6. The pressure relief device (100) according to claim 5, characterized in that, The sum of the flow areas of all the first pressure relief ports (12) is greater than or equal to the sum of the flow areas of all the second pressure relief ports (22).

7. The pressure relief device (100) according to claim 5, characterized in that, When there are multiple first pressure relief ports (12), the multiple first pressure relief ports (12) are spaced apart along the same circumferential direction; and / or, When there are multiple second pressure relief ports (22), the multiple second pressure relief ports (22) are arranged at circumferential intervals along the conveying channel (21).

8. The pressure relief device (100) according to claim 1, characterized in that, The pressure relief chamber (11) includes a first sidewall (111) and a second sidewall (112) disposed opposite to each other. The conveying channel (21) extends from the first sidewall (111) to the outside of the body (10). The first pressure relief port (12) is disposed on the second sidewall (112).

9. The pressure relief device (100) according to claim 8, characterized in that, The second pressure relief port (22) extends radially along the conveying channel (21); or, Along the inner and outer directions of the conveying channel (21), the second pressure relief port (22) is inclined toward the first sidewall (111).

10. The pressure relief device (100) according to any one of claims 1 to 9, characterized in that, The body (10) is provided with a connecting part (13), which is located on the side of the body (10) away from the first pressure relief port (12) for at least connecting the body (10) to a predetermined structure.

11. A battery cell (200), characterized in that, The battery cell (200) includes a pressure relief device (100) and a pressure relief valve (210) as described in any one of claims 1 to 10, wherein the pressure relief device (100) and the pressure relief valve (210) are spaced apart at the same end of the battery cell (200), and the delivery channel (21) communicates with the interior of the battery cell (200).

12. The battery cell (200) according to claim 11, characterized in that, The battery cell (200) includes at least one of the pressure relief devices (100). When there are multiple pressure relief devices (100), the multiple pressure relief devices (100) are spaced apart on opposite sides of the pressure relief valve (210).

13. A battery pack (300), characterized in that, The battery pack (300) includes the battery cell (200) as described in any one of claims 11 to 12.

Images