Pressure release valve, end cover assembly, battery monomer, battery and electric device

Abstract

The invention relates to a pressure release valve, an end cover assembly, a battery monomer, a battery and an electric device, and a plugging structure is used for plugging a part, facing a first side, of an operation hole, so that an overflowing channel is not communicated with the first side of an end cover. When the end cover assembly is assembled in the single battery, communication between the interior of the single battery and the outside can be cut off, and effective water insulation is realized. As the plugging structure is separated from the end cover when being subjected to the pressure pointing from the second side to the first side, when the internal pressure of the battery monomer is increased, the plugging structure is driven to at least partially deform towards the first side, so that the plugging structure is separated from the end cover, the air pressure can be discharged from the flowing channel to the first side, and effective pressure relief is realized. And when the internal pressure of the battery monomer is reduced to a certain value, the plugging structure can cover the working hole again so as to cut off the communication between the overflowing channel and the first side. By means of the design, effective water insulation and pressure relief are achieved, meanwhile, reutilization can be achieved, and the production cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a pressure relief valve, an end cover assembly, a battery monomer, a battery and an electric device. BACKGROUND

[0002] With the rapid development of battery technology, higher requirements are put forward for the reliability of batteries. In order to reduce the risk caused by the increase of internal pressure during the use of the battery, an explosion-proof valve is usually arranged on the end cover of the battery. However, due to the structural design of the traditional explosion-proof valve, most of them are disposable and cannot be reused, which increases the production cost of the battery. SUMMARY

[0003] Therefore, it is necessary to provide a pressure relief valve, an end cover assembly, a battery monomer, a battery and an electric device, which can be reused while effectively preventing water and pressure relief, thereby reducing the production cost.

[0004] In a first aspect, the present application provides an end cover assembly, comprising: an end cover having a first side and a second side in a thickness direction of the end cover, and an operation hole penetrating through the first side and the second side; and a pressure relief valve comprising a valve body and a blocking structure, the valve body being at least partially arranged in the operation hole and forming a flow passage with the second side, and the blocking structure being arranged in a portion of the operation hole facing the first side and being configured to be separated from the end cover at least partially when subjected to a pressure from the second side to the first side, so that the flow passage is communicated with the first side.

[0005] The end cover assembly described above uses the blocking structure to block the portion of the operation hole facing the first side, so that the flow passage is not communicated with the first side of the end cover. When the end cover assembly is assembled in the battery monomer, the communication between the inside of the battery monomer and the outside is interrupted, and effective water prevention is achieved. Since the blocking structure is separated from the end cover when subjected to the pressure from the second side to the first side, when the internal pressure of the battery monomer increases, the blocking structure is at least partially deformed towards the first side, so that it is separated from the end cover, so that the gas pressure can be discharged from the flow passage to the first side, and effective pressure relief is achieved. When the internal pressure of the battery monomer decreases to a certain value, the blocking structure covers the operation hole again to interrupt the communication between the flow passage and the first side. In this way, by using the separation between the blocking structure and the end cover instead of damaging the blocking structure, the pressure relief valve can be reused while effectively preventing water and pressure relief, thereby reducing the production cost.

[0006] In some embodiments, the blocking structure comprises a first blocking member arranged on the valve body and a second blocking member arranged on a side of the first blocking member away from the valve body, both the first blocking member and the second blocking member sealingly abutting the circumferential inner wall of the working hole, and both being configured to be separated from the end cover when subjected to pressure from the second side to the first side. In this way, the first blocking member and the second blocking member are introduced to achieve double-layer sealing at one end of the working hole, further improving the reliability of water isolation.

[0007] In some embodiments, a pressure cavity is formed between the first blocking member and the second blocking member, and the pressure cavity is configured to be in communication with the overflow passage when the first blocking member is separated from the end cover. In this way, the pressure cavity is arranged between the first blocking member and the second blocking member, so that the first blocking member and the second blocking member are stably opened in sequence, making the pressure relief more reliable and stable. At the same time, the pressure cavity is arranged on the side of the first blocking member facing the second blocking member, leaving a reasonable space for the separation of the first blocking member, reducing the probability of the opening of the first blocking member being interfered by the second blocking member.

[0008] In some embodiments, the second blocking member comprises a connecting portion and a blocking portion, the blocking portion being connected to the first blocking member through the connecting portion and sealingly abutting the circumferential inner wall of the working hole, and at least part of the pressure cavity being enclosed among the blocking portion, the connecting portion and the first blocking member. In this way, the second blocking member is designed as the blocking portion and the connecting portion, facilitating the connection of the first blocking member and the second blocking member to achieve stable double sealing.

[0009] In some embodiments, the circumferential edge of the blocking portion radially exceeds the connecting portion and is arranged to be bent towards the side of the valve body. In this way, the circumferential edge of the blocking portion radially exceeds the connecting portion and is arranged to be bent towards the side of the valve body, facilitating the abutment between the blocking portion and the inner wall of the working hole to achieve better sealing.

[0010] In some embodiments, the projection of the second blocking member along the direction of the axis of the pressure relief valve covers the first blocking member and radially exceeds the first blocking member. In this way, the projection of the second blocking member along the axial direction covers the first blocking member, so that the size of the second blocking member is larger than that of the first blocking member, making it easier to deform, and thus the air pressure can sequentially push open the first blocking member and the second blocking member to achieve stable pressure relief.

[0011] In some embodiments, the working hole comprises a first hole section, a second hole section and a third hole section arranged in sequence along the thickness direction of the end cover, the third hole section being arranged close to the second side, the valve body being at least partially arranged in the third hole section, the first blocking member sealingly abutting the inner wall of the second hole section, and the second blocking member sealingly abutting the inner wall of the first hole section. In this way, the working hole is divided into the first hole section, the second hole section and the third hole section along the axial direction, facilitating the assembly of the valve body, the first blocking member and the second blocking member in the working hole to achieve effective water isolation and pressure relief.

[0012] In some embodiments, the cross-sectional area A1 of the second hole section gradually increases from the end of the second hole section close to the third hole section to the end of the second hole section close to the first hole section, and the side surface of the first blocking piece away from the second blocking piece abuts against the inner wall of the second hole section. In this way, the second hole section is designed as a variable cross-section structure, so that the first blocking piece is more easily self-centered in the second hole section, thereby facilitating the rapid assembly of the blocking structure. At the same time, it is also convenient for the gas pressure to push the first blocking piece open, so as to achieve effective and stable pressure relief.

[0013] In some embodiments, the side surface of the first blocking piece away from the second blocking piece includes a sealing surface annularly surrounding the axis of the pressure relief valve, and the sealing surface and the inner wall of the second hole section are both inclined relative to the axis of the pressure relief valve; wherein the angle θ1 between the sealing surface and the axis is greater than or equal to the angle θ2 between the inner wall of the second hole section and the axis. In this way, the angle between the sealing surface and the axis is greater than or equal to the angle between the second hole section and the axis, which facilitates the rapid assembly of the first blocking piece in the second hole section, reduces the requirements for the machining precision and assembly precision of the pressure relief valve. At the same time, it is also convenient for the first blocking piece to be pressed tightly against the inner wall of the second hole section, so as to achieve better sealing.

[0014] In some embodiments, the valve body includes a clamping portion and a fixed portion connected with the clamping portion, the fixed portion is arranged in the work hole, the clamping portion abuts against the surface of the end cover facing the second side, the blocking structure is connected with the fixed portion, and the clamping portion, the fixed portion and the end cover define a flow passage. In this way, the valve body is designed as a clamping portion and a fixed portion, which facilitates the stable clamping of the valve body in the work hole; at the same time, it is also convenient to form a flow passage to achieve effective pressure relief.

[0015] In some embodiments, at least one of the surface of the end cover facing the second side and the clamping portion is provided with a flow groove communicating with the second side, the fixed portion and the inner wall of the work hole form a flow gap, and the flow groove and the flow gap communicate to define a flow passage. In this way, the flow groove and the flow gap are introduced, so that the gas flow can be stably discharged to the first side during pressure relief.

[0016] In some embodiments, the flow groove is arranged on the surface of the end cover facing the second side, and one end of the flow groove extends to communicate with the work hole. In this way, the one end of the flow groove exceeds the clamping portion, and the other end communicates with the work hole, so that the gas flow can stably pass through the flow groove into the flow gap to achieve effective and stable pressure relief.

[0017] In some embodiments, the flow groove includes a plurality of flow grooves, and at least part of the flow grooves are distributed at intervals around the outer periphery of the work hole. In this way, the flow grooves are distributed at intervals around the outer periphery of the work hole, so that the gas flow on the second side enters the flow gap from different directions, which can slow down the pressure relief pressure and is beneficial to improve the pressure relief efficiency.

[0018] In some embodiments, the side of the snap-fit ​​portion facing the sealing structure includes an abutment surface surrounding the outer periphery of the fixing portion. The area A2 of the cross-section of the abutment surface perpendicular to the axis of the pressure relief valve gradually increases from the end of the abutment surface near the fixing portion to the end of the abutment surface away from the fixing portion. This design makes the cross-sectional area of ​​the abutment surface smaller closer to the fixing portion, allowing the valve body assembly to achieve self-centering under the guidance of the abutment surface, reducing the requirements for assembly accuracy. At the same time, the design of the abutment surface, while ensuring stable contact with the end cover, easily forms a gap with the surface of the end cover, facilitating airflow into the flow channel and facilitating stable pressure relief.

[0019] In some embodiments, the side of the snap-fit ​​portion facing away from the sealing structure includes a guide surface. The area A3 of the cross-section of the guide surface perpendicular to the axis of the pressure relief valve gradually decreases from the end of the guide surface near the fixing portion to the end of the guide surface away from the fixing portion. This design, with its rationally designed guide surface structure, allows the valve body to be quickly and stably assembled into the working hole under the guidance of the guide surface, improving assembly efficiency.

[0020] Secondly, this application provides a pressure relief valve, which includes: a valve body; and a sealing structure disposed on the valve body, wherein the portion of the sealing structure extending radially beyond the valve body is configured to be able to warp and deform in a direction away from the valve body.

[0021] In some embodiments, the sealing structure includes a first sealing member on the valve body and a second sealing member on the side of the first sealing member facing away from the valve body. Both the first and second sealing members are configured to warp and deform in the direction away from the valve body. This design, by introducing the first and second sealing members, achieves a double-layer seal at one end of the working hole, further improving the reliability of water sealing.

[0022] In some embodiments, the valve body includes a snap-fit ​​portion and a fixing portion connected to the snap-fit ​​portion, and a sealing structure is connected to the fixing portion and spaced apart from the snap-fit ​​portion. This design, with the valve body consisting of a snap-fit ​​portion and a fixing portion, facilitates the stable locking of the valve body in the working hole; at the same time, it also facilitates the formation of a flow passage to achieve effective pressure relief.

[0023] Thirdly, this application provides a battery cell, which includes the end cap assembly of any of the above.

[0024] Fourthly, this application provides a battery comprising the above-mentioned battery cells.

[0025] Fifthly, this application provides an electrical device that includes the aforementioned battery. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the vehicle structure in some embodiments of this application.

[0027] Figure 2 This is an exploded view of the battery in some embodiments of this application.

[0028] Figure 3 This is a schematic diagram of the structure of a single battery cell in some embodiments of this application.

[0029] Figure 4 This is a top view of the end cap assembly in some embodiments of this application.

[0030] Figure 5 This is a structural cross-sectional view of the end cap assembly in some embodiments of this application.

[0031] Figure 6 This is a cross-sectional view of the pressure relief valve in some embodiments of this application.

[0032] Figure 7 The following is a cross-sectional view of the end cap structure in some embodiments of this application.

[0033] Figure 8 This is a schematic diagram of the bottom structure of the end cap in some embodiments of this application.

[0034] 1000, Vehicle; 100, Battery; 200, Controller; 300, Motor; 110, Battery Cell; 120, Battery Housing; 121, First Part; 122, Second Part; 10, End Cap Assembly; 1, End Cap; 11, First Side; 12, Second Side; 13, Working Hole; 131, First Hole Section; 132, Second Hole Section; 133, Third Hole Section; 14, Flow Groove; X, Thickness Direction; 2, Pressure Relief Valve; 21. Valve body; 211. Snap-fit ​​part; 21a. Abutment surface; 21b. Guide surface; 212. Fixing part; 22. Sealing structure; 221. First sealing element; 22a. Sealing surface; 222. Second sealing element; 22b. Circumferential edge; 223. Pressure cavity; 22c. Connecting part; 22d. Sealing part; 23. Axis; 24. Flow gap; 3. Flow channel; 20. Electrode assembly; 30. Housing; 31. Opening. Detailed Implementation

[0035] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0036] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0037] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0038] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0040] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0041] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0042] During battery cell recycling or manufacturing processes, varying degrees of gas generation can occur inside the cell. If this gas cannot be released in time, it can lead to increased internal pressure, causing the cell to swell and deform, thus affecting its normal performance. Traditional pressure relief methods typically involve installing a rupture membrane in the electrolyte injection hole of the end cap. When the internal pressure of the cell reaches a certain value, the rupture membrane ruptures, allowing the internal gas to escape, achieving effective pressure relief. However, this method relies on a single-use rupture membrane, which cannot be reused, increasing battery production costs.

[0043] Based on this, to address the issue of traditional pressure relief structures being mostly single-use, leading to increased production costs, this application provides an end cap assembly. This assembly utilizes a sealing structure to block the portion of the working hole facing the first side, preventing the flow channel from connecting to the first side of the end cap. When the end cap assembly is assembled in a battery cell, it isolates the battery cell's interior from the outside, achieving effective water isolation. Since the sealing structure separates from the end cap when subjected to pressure from the second side to the first side, when the internal pressure of the battery cell increases, it causes at least a portion of the sealing structure to deform towards the first side, separating it from the end cap. This allows air pressure to be released from the flow channel to the first side, achieving effective pressure relief. When the internal pressure of the battery cell decreases to a certain value, the sealing structure re-covers the working hole, further isolating the flow channel from the first side. This design, through the separation of the sealing structure from the end cap rather than destroying the sealing structure, achieves effective water isolation and pressure relief while allowing for reuse, reducing production costs.

[0044] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of vehicle 1000 in some embodiments of this application.

[0045] This application provides an electrical device that uses a battery 100 as a power source. The electrical device can be, but is not limited to, a mobile phone, tablet, laptop, electric toy, power tool, electric vehicle, electric car, ship, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0046] It should be understood that the technical solutions described in the embodiments of this application are not limited to the electrical devices described above, but for the sake of brevity, the following embodiments all use a vehicle 1000 as an example for illustration.

[0047] Vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery 100 is installed inside vehicle 1000, which can be located at the bottom, front, or rear of vehicle 1000. Battery 100 can be used to power vehicle 1000; for example, battery 100 can serve as the operating power source for vehicle 1000. Vehicle 1000 may also include a controller 200 and a motor 300. Controller 200 controls the battery 100 to supply power to motor 300, for example, to meet the power needs of vehicle 1000 during starting, navigation, and driving.

[0048] In some embodiments of this application, the battery 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0049] Please refer to Figure 2 , Figure 2 This is an exploded view of battery 100 in some embodiments of this application.

[0050] The battery 100 includes a housing and battery cells 110, with the battery cells 110 housed within the battery housing 120. The battery housing 120 provides a cavity for the battery cells 110 and can have various structures. In some embodiments, the housing may include a first portion 121 and a second portion 122, which overlap each other, together defining a cavity for accommodating the battery cells 110. The second portion 122 may be a hollow structure with an opening 31 at one end, while the first portion 121 may be a plate-like structure, covering the opening side of the second portion 122 so that the first portion 121 and the second portion 122 together define the cavity; alternatively, both the first portion 121 and the second portion 122 may be hollow structures with an opening 31 on one side, with the opening side of the first portion 121 overlapping the opening side of the second portion 122. Of course, the battery box 120 formed by the first part 121 and the second part 122 can be of various shapes, such as cylinder, cuboid, etc.

[0051] In battery 100, there can be multiple battery cells 110, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 110 are connected in both series and parallel configurations. Multiple battery cells 110 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 110 is housed within a casing. Alternatively, battery 100 can also consist of multiple battery cells 110 first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is then housed within a battery casing 120. Battery 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 110.

[0052] Each battery cell 110 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited to these.

[0053] A battery cell 110 refers to the smallest unit that makes up a battery 100. A battery cell 110 includes an electrode assembly 20, a housing 30, and an end cap assembly 10.

[0054] Electrode assembly 20 is the component in battery cell 110 where electrochemical reactions occur. Battery cell 110 may contain one or more electrode assemblies 20. Electrode assembly 20 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of electrode assembly 20, while the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of battery 100, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals to form a current loop.

[0055] The housing 30 is an assembly used to cooperate with the end cap 1 in the end cap assembly 10 to form the internal environment of the battery cell 110. This internal environment can accommodate the electrode assembly 20, electrolyte, and other components. The housing 30 and the end cap 1 can be independent components. An opening 31 can be provided on the housing 30, and the end cap 1 can close the opening 31 to form the internal environment of the battery cell 110. Alternatively, the end cap 1 and the housing 30 can be integrated. Specifically, the end cap 1 and the housing 30 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 30, the end cap 1 closes the housing 30. The housing 30 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 30 can be determined according to the specific shape and size of the electrode assembly 20. The material of the housing 30 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. This application embodiment does not impose any special limitations on this.

[0056] The end cap assembly 10 includes an end cap 1, which is a component that covers the opening 31 of the housing 30 to isolate the internal environment of the battery cell 110 from the outside. The shape of the end cap 1 can be adapted to the shape of the housing 30 to fit it. Optionally, the end cap 1 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 1 is less prone to deformation under pressure and impact, allowing the battery cell 110 to have higher structural strength and improved safety performance. Functional components such as electrode terminals can be provided on the end cap 1. The electrode terminals can be used to electrically connect to the electrode assembly 20 for outputting or inputting electrical energy into the battery cell 110. In some embodiments, the end cap 1 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell 110 reaches a threshold. In some embodiments, an insulating member can also be provided on the inner side of the end cap 1, which can be used to isolate the electrical connection portion 22c within the housing 30 from the end cap 1 to reduce the risk of short circuits. For example, the insulating element can be made of plastic, rubber, etc.

[0057] According to some embodiments of this application, please refer to Figure 4 and Figure 5 This application provides an end cap assembly 10, which includes an end cap 1 and a pressure relief valve 2. The end cap 1 has a first side 11 and a second side 12 along its thickness direction X, and has a working hole 13 penetrating the first side 11 and the second side 12. The pressure relief valve 2 includes a valve body 21 and a sealing structure 22. The valve body 21 is at least partially installed in the working hole 13 and forms a flow passage 3 communicating with the second side 12 between itself and the end cap 1. The sealing structure 22 seals the portion of the working hole 13 facing the first side 11 and is configured to at least partially separate from the end cap 1 when subjected to pressure from the second side 12 toward the first side 11, so that the flow passage 3 communicates with the first side 11.

[0058] The internal environment of the battery cell 110 is defined by the end cap 1 and the housing 30. When the pressure relief valve 2 is not installed, the working hole 13 on the end cap 1 communicates with the internal environment of the battery cell 110. The working hole 13 can be of various types; it can be a liquid injection hole on the end cap 1, an explosion-proof hole, or a hole separately opened on the end cap 1 for specific operations. The shape of the working hole 13 can also be designed in various ways. For example, the working hole 13 can be designed as a straight hole extending along the thickness direction X of the end cap 1. In this case, during pressure relief, the sealing structure 22 will be raised and flipped under the action of air pressure, creating a gap between the sealing structure 22 and the inner wall of the working hole 13. Alternatively, the working hole 13 can also be designed as a multi-segment structure with different diameters, in which case the sealing structure 22 can abut against the inner walls between different segments.

[0059] The first side 11 and the second side 12 are the two sides of the end cap 1 along its thickness direction X. For ease of understanding, taking the interior of the battery cell 110 as a reference, the first side 11 can be the side of the end cap 1 facing away from the interior of the battery cell 110, and the second side 12 can be the side of the end cap 1 facing the interior of the battery cell 110. When the pressure relief valve 2 is installed in the working hole 13, the flow passage 3 formed by the valve body 21 in the working hole 13 communicates with the second side 12, allowing the airflow inside the battery cell 110 to enter the flow passage 3, facilitating the increased air pressure to open the sealing structure 22.

[0060] The valve body 21 refers to the structure used for assembly in the working hole 13, which forms a flow passage 3 with the working hole 13. There are various ways to fix the valve body 21 in the working hole 13, such as connecting it to the sealing structure 22; or snapping it into the hole wall of the working hole 13. Alternatively, a pressure cap or similar structure can be provided on the surface of the end cap 1 facing the second side 12, allowing the valve body 21 to be pressed into the working hole 13. The flow passage 3 can be designed in various ways, such as the flow passage 3 being entirely formed by the hole wall of the working hole 13 and the outer surface of the valve body 21; or, a portion of the flow passage 3 being formed by the hole wall of the working hole 13 and the outer surface of the valve body 21, with another portion located inside the valve body 21 and extending to the outer surface of the valve body 21, communicating with the second side 12.

[0061] The sealing structure 22 refers to the portion of the working hole 13 facing the first side 11 that is sealed. It can isolate the flow channel 3 from the first side 11, reducing the entry of gas or liquid from the first side 11 into the flow channel 3, thus achieving effective water isolation. When the internal pressure of the battery cell 110 increases to a certain value, the air pressure from the second side 12 to the first side 11 pushes open the sealing structure 22, separating it from the end cap 1 and forming a gap that allows airflow in the flow channel 3 to drain towards the first side 11. The sealing structure 22 can be an elastic component, such as rubber material, which separates from the end cap 1 and forms a gap under the action of air pressure by tilting deformation. When the air pressure decreases, the sealing structure 22 automatically recovers its deformation and re-seales with the end cap 1. In some examples, when the internal air pressure of the battery cell 110 reaches above 0.01 MPa, the sealing structure 22 can be pushed open to achieve pressure relief and air venting.

[0062] Compared to the sealing structure 22, the valve body 21 is positioned closer to the second side 12 within the working hole 13. When the sealing structure 22 is inserted into the working hole 13 and connected to the valve body 21, the valve body 21 and the sealing structure 22 form a snap-fit ​​structure, ensuring that both are stably engaged within the working hole 13. The connection between the sealing structure 22 and the valve body 21 can be either a fixed connection or a detachable connection. Fixed connections can be, but are not limited to, bonding or integral molding; integral molding connections can be achieved through injection molding, machining, or 3D printing. Detachable connections can be, but are not limited to, snap-fit. Additionally, in some embodiments, when the sealing structure 22 is inserted into the working hole 13, it can also be engaged with the hole wall of the working hole 13.

[0063] With this design, the pressure relief valve 2 can effectively isolate water and relieve pressure, while being reusable, thus reducing production costs.

[0064] Optionally, according to some embodiments of this application, please refer to Figure 5The sealing structure 22 includes a first sealing member 221 disposed on the valve body 21 and a second sealing member 222 disposed on the side of the first sealing member 221 facing away from the valve body 21. Both the first sealing member 221 and the second sealing member 222 are sealed against the circumferential inner wall of the working hole 13, and both are configured to separate from the end cap 1 when subjected to pressure from the second side 12 to the first side 11.

[0065] The second sealing element 222 is disposed on the side of the first sealing element 221 facing away from the valve body 21. This means that the first sealing element 221 and the second sealing element 222 are sequentially distributed along the thickness direction X of the end cover 1, achieving a double seal in the thickness direction X of the end cover 1. When the internal pressure of the battery cell 110 exceeds a certain value, such as a pressure value greater than or equal to 0.01 MPa, the air pressure can first cause the first sealing element 221 to warp and deform, separating it from the end cover 1, such as separating it from at least part of the inner wall of the working hole 13, allowing airflow to be discharged between the first sealing element 221 and the second sealing element 222. Then, the air pressure further drives the second sealing element 222 to warp and deform, causing the second sealing element 222 to also separate from the end cover 1, allowing airflow to be discharged outside the second sealing element 222.

[0066] When the internal air pressure of the battery cell 110 decreases, the first sealing member 221 can re-abut against the circumferential inner wall of the working hole 13 before the second sealing member 222. The materials of the first sealing member 221 and the second sealing member 222 can be the same or different. For example, the elastic modulus of the material of the second sealing member 222 can be less than that of the material of the first sealing member 221. This satisfies the air pressure required to open the first sealing member 221 and can also effectively open the second sealing member 222, thus achieving effective pressure relief.

[0067] The circumferential inner wall of the working hole 13 refers to the annular inner wall along its own circumference on the working hole 13. When the first sealing member 221 and the second sealing member 222 respectively abut against the circumferential inner wall of the working hole 13, the end of the working hole 13 facing the first side 11 can be sealed, reducing the possibility of external gas or liquid entering the battery cell 110 and achieving effective water isolation.

[0068] To facilitate the warping deformation of the first sealing element 221 and the second sealing element 222, both the first sealing element 221 and the second sealing element 222 can be made of elastic materials, such as rubber. At the same time, the shapes of the first sealing element 221 and the second sealing element 222 can be designed in various ways, such as, but not limited to, circles, ovals, squares, pentagons, etc.

[0069] Furthermore, the first sealing element 221 is connected to the valve body 21 in various ways, such as threaded connection, snap-fit, adhesive bonding, or integral molding. Similarly, the connection between the second sealing element 222 and the first sealing element 221 can also be, but is not limited to, threaded connection, snap-fit, adhesive bonding, or integral molding. In some specific embodiments, the first sealing element 221, the second sealing element 222, and the valve body 21 are an integrated structure.

[0070] This design introduces a first sealing element 221 and a second sealing element 222 to achieve a double-layer seal on one end of the working hole 13, further improving the reliability of water-proofing.

[0071] Optionally, according to some embodiments of this application, please refer to Figure 5 A pressure cavity 223 is formed between the first sealing member 221 and the second sealing member 222. The pressure cavity 223 is configured to communicate with the flow channel 3 when the first sealing member 221 is separated from the end cap 1.

[0072] The pressure chamber 223 refers to the space located between the first sealing member 221 and the second sealing member 222. When the first sealing member 221 is opened, airflow flows into the pressure chamber 223, increasing the air pressure in the pressure chamber 223. This air pressure then pushes open the second sealing member 222, causing the second sealing member 222 to separate from the end cap 1. When both the first sealing member 221 and the second sealing member 222 abut against the circumferential wall of the working hole 13, the pressure chamber 223 is sealed between the first sealing member 221, the second sealing member 222, and the inner wall of the working hole 13.

[0073] This design, with a pressure cavity 223 between the first sealing element 221 and the second sealing element 222, ensures that the first sealing element 221 and the second sealing element 222 open stably and sequentially, making pressure relief more reliable and stable. Simultaneously, the pressure cavity 223 is located on the side of the first sealing element 221 facing the second sealing element 222, providing reasonable space for the separation of the first sealing element 221 and reducing the likelihood of interference from the second sealing element 222 during the opening of the first sealing element 221.

[0074] Optionally, according to some embodiments of this application, please refer to Figure 5 The second sealing member 222 includes a connecting part 22c and a sealing part 22d. The sealing part 22d is connected to the first sealing member 221 through the connecting part 22c and seals against the circumferential inner wall of the working hole 13. The sealing part 22d, the connecting part 22c and the first sealing member 221 enclose each other to form at least a portion of the pressure cavity 223.

[0075] The sealing part 22d refers to the structure that seals the working hole 13. Its shape can be, but is not limited to, circular, elliptical, square, pentagonal, etc. Of course, it can also be an irregular shape, as long as it can seal one end of the working hole 13. The connecting part 22c refers to the structure that connects the sealing part 22d and the first sealing member 221. The connecting part 22c can be designed as a cylindrical structure or a square structure, etc.

[0076] The connection between the sealing part 22d and the connecting part 22c can take various forms, such as threaded connection, snap-fit, adhesive bonding, or integral molding. Similarly, the connection between the connecting part 22c and the first sealing member 221 can also be, but is not limited to, threaded connection, snap-fit, adhesive bonding, or integral molding. In some specific embodiments, the sealing part 22d, the connecting part 22c, and the first sealing member 221 are an integral structure.

[0077] This design, in which the second sealing element 222 is designed as a sealing part 22d and a connecting part 22c, facilitates the connection between the first sealing element 221 and the second sealing element 222 to achieve a stable double seal.

[0078] Optionally, according to some embodiments of this application, please refer to Figure 5 The circumferential edge 22b of the sealing part 22d extends beyond the connecting part 22c in the radial direction of the pressure relief valve 2, and is bent along the side facing the valve body 21.

[0079] The circumferential edge 22b of the sealing portion 22d extends radially beyond the connecting portion 22c and bends towards one side of the valve body 21, thus presenting an umbrella-like structure with the connecting portion 22c. When the circumferential edge 22b of the sealing portion 22d abuts against the inner wall of the working hole 13, it is equivalent to covering the inner wall of the vent hole. Thus, when the sealing portion 22d is subjected to pressure from the first side 11 to the second side 12, it will tightly abut against the inner wall of the working hole 13. At the same time, the greater the pressure, the better the sealing effect between the circumferential edge 22b of the sealing portion 22d and the inner wall of the working hole 13.

[0080] In addition, the circumferential edge 22b of the sealing part 22d is bent, which allows for a certain elastic deformation space when it comes into contact with the inner wall of the working hole 13, so that there is a certain pre-compression stress between the sealing part 22d and the inner wall of the working hole 13, thereby improving the sealing effect.

[0081] This design extends the circumferential edge 22b of the sealing part 22d radially beyond the connecting part 22c and bends it toward the side of the valve body 21, which facilitates the contact between the sealing part 22d and the inner wall of the working hole 13, thus achieving a better seal.

[0082] Optionally, according to some embodiments of this application, please refer to Figure 5The projection of the second sealing element 222 along the axis 23 of the pressure relief valve 2 covers the first sealing element 221 and extends beyond the first sealing element 221 radially along the pressure relief valve 2.

[0083] The projection of the second sealing element 222 along the axis 23 of the pressure relief valve 2 covers the first sealing element 221, indicating that the surface area of ​​the second sealing element 222 facing the valve body 21 is larger than the surface area of ​​the first sealing element 221 facing the valve body 21. Because of its larger size, the second sealing element 222 is more easily opened by air pressure compared to the first sealing element 221, allowing the increased air pressure to sequentially open both the first and second sealing elements 221, thus achieving stable pressure relief.

[0084] In some specific embodiments, the second sealing member 222 includes a sealing portion 22d and a connecting portion 22c connected between the sealing portion 22d and the first sealing member 221. The projection of the sealing portion 22d along the axis 23 of the pressure relief valve 2 covers the first sealing member 221 and extends beyond the first sealing member 221 along the radial direction of the pressure relief valve 2.

[0085] This design allows the projection of the second sealing element 222 along the axial direction to cover the first sealing element 221, making the size of the second sealing element 222 larger than that of the first sealing element 221. This makes it easier for the second sealing element 222 to deform, thereby allowing the air pressure to sequentially push open the first sealing element 221 and the second sealing element 222, achieving stable pressure relief.

[0086] Optionally, according to some embodiments of this application, please refer to Figure 6 and Figure 7 The working hole 13 includes a first hole section 131, a second hole section 132 and a third hole section 133 distributed sequentially along the thickness direction X of the end cap 1. The third hole section 133 is located close to the second side 12. The valve body 21 is at least partially installed in the third hole section 133. The first sealing member 221 is sealed against the inner wall of the second hole section 132 and the second sealing member 222 is sealed against the inner wall of the first hole section 131.

[0087] The working hole 13 has a three-section structure in the thickness direction X of the end cap 1. The first section 131 is close to the first side 11, the third section 133 is close to the second side 12, and the second section 132 is located between the first section 131 and the third section 133. When the valve body 21 is at least partially assembled in the third section 133, a flow channel 3 is formed between the valve body 21 and the inner wall of the third section 133. When the sealing structure 22 seals the portion of the working hole 13 facing the first side 11, the first sealing member 221 seals against the inner wall of the second section 132, and the second sealing member 222 seals against the inner wall of the first section 131, achieving a double seal.

[0088] The first hole segment 131, the second hole segment 132, and the third hole segment 133 can all be circular holes, and their diameters can be designed to be different. For example, the maximum diameter of the second hole segment 132 can be greater than the maximum diameter of the third hole segment 133, and the maximum diameter of the first hole segment 131 can be greater than the maximum diameter of the second hole segment 132. When the maximum diameter of the first hole segment 131 is greater than the maximum diameter of the second hole segment 132, the second sealing member 222 can seal against the bottom wall of the first hole segment 131. It should be noted that the inner wall of the first hole segment 131 includes the side wall and the bottom wall surrounding one end of the second hole segment 132, and the second sealing member 222 abuts against this bottom wall.

[0089] In addition, the first hole section 131, the second hole section 132 and the third hole section 133 can all be designed as equal diameter circular holes or as variable diameter circular holes; or, at least one of the first hole section 131, the second hole section 132 and the third hole section 133 can be designed as a variable diameter circular hole.

[0090] This design divides the working hole 13 into a first hole section 131, a second hole section 132, and a third hole section 133 along the axis 23, which facilitates the assembly of the valve body 21, the first sealing component 221, and the second sealing component 222 in the working hole 13, so as to achieve effective water isolation and pressure relief.

[0091] Optionally, according to some embodiments of this application, please refer to Figure 6 and Figure 7 The cross-sectional area A1 of the second hole segment 132 gradually increases from the end of the second hole segment 132 near the third hole segment 133 to the end of the second hole segment 132 near the first hole segment 131. The side of the first sealing member 221 facing away from the second sealing member 222 abuts against the inner wall of the second hole segment 132.

[0092] The cross-sectional area of ​​the second hole segment 132 is larger as it gets closer to the first hole segment 131, and its inner wall can present or approximate a conical surface. In this way, the sealing structure 22 can achieve self-centering under the guidance of the inner wall of the second hole segment 132 during assembly, allowing the sealing structure 22 to be quickly assembled in the appropriate position.

[0093] Furthermore, the inner wall of the second orifice 132 is conical, which allows for a larger space on the side of the first sealing member 221 facing away from the valve body 21. This makes it easier for the gas pressure inside the battery cell 110 to push open the first sealing member 221 when the internal gas pressure increases, achieving effective and stable pressure relief. In some specific embodiments, the second orifice 132 is a circular hole, and the diameter of the second orifice 132 gradually increases from the end of the second orifice 132 near the third orifice 133 to the end of the second orifice 132 near the first orifice 131.

[0094] This design, with the second orifice 132 having a variable cross-section, makes it easier for the first sealing element 221 to self-center within the second orifice 132, thus facilitating the rapid assembly of the sealing structure 22. Simultaneously, it also allows for the pneumatic opening of the first sealing element 221, achieving effective and stable pressure relief.

[0095] Optionally, according to some embodiments of this application, please refer to Figure 6 and Figure 7 The side of the first sealing member 221 facing away from the second sealing member 222 includes a sealing surface 22a that is annular around the axis 23 of the pressure relief valve 2. Both the sealing surface 22a and the inner wall of the second orifice 132 are inclined relative to the axis 23 of the pressure relief valve 2. The angle θ1 between the sealing surface 22a and the axis 23 is greater than or equal to the angle θ2 between the inner wall of the second orifice 132 and the axis 23.

[0096] The sealing surface 22a refers to the annular curved surface around the axis 23 of the pressure relief valve 2, which is inclined relative to the axis 23 of the pressure relief valve 2 to present a portion of a conical surface. Since the angle between the sealing surface 22a and the axis 23 is greater than or equal to the angle between the second orifice 132 and the axis 23, when the first sealing member 221 is inserted into the second orifice 132, the sealing surface 22a can easily abut against the inner wall of the second orifice 132 to form a seal.

[0097] Meanwhile, when the sealing surface 22a abuts against the inner wall of the second hole section 132, since the angle between the sealing surface 22a and the axis 23 is greater than or equal to the angle between the second hole section 132 and the axis 23, there is space between the lower part of the sealing surface 22a and the second hole section 132, which facilitates the structural deformation of the first sealing member 221 along the side facing the valve body 21 during assembly, so that the first sealing member 221 is pressed more tightly against the inner wall of the second hole section 132, achieving better sealing.

[0098] This design ensures that the angle between the sealing surface 22a and the axis 23 is greater than or equal to the angle between the second bore section 132 and the axis 23. This facilitates the rapid assembly of the first sealing element 221 into the second bore section 132, reducing the precision requirements for the machining and assembly of the pressure relief valve 2. Simultaneously, it also allows the first sealing element 221 to be pressed firmly against the inner wall of the second bore section 132, achieving a better seal.

[0099] Optionally, according to some embodiments of this application, please refer to Figure 5 The valve body 21 includes a snap-fit ​​part 211 and a fixing part 212 connected to the snap-fit ​​part 211. The fixing part 212 passes through the working hole 13. The snap-fit ​​part 211 abuts against a surface of the end cap 1 facing the second side 12. The sealing structure 22 is connected to the fixing part 212. The snap-fit ​​part 211, the fixing part 212 and the end cap 1 define and form a flow passage 3.

[0100] The snap-fit ​​part 211 abuts against a surface of the end cap 1 facing the second side 12, and the sealing structure 22 seals a portion of the working hole 13 facing the first side 11; at the same time, a fixing part 212 is connected between the snap-fit ​​part 211 and the sealing structure 22. In this way, the snap-fit ​​part 211 and the sealing structure 22 can be combined to form a clamping structure, so that the pressure relief valve 2 is stably clamped in the working hole 13.

[0101] The connection method between the fixing part 212 and the locking part 211 and the sealing structure 22 can be adhesive bonding, snap-fitting, threaded connection, integral molding, etc. Specifically, in some embodiments, the locking part 211, the fixing part 212 and the sealing structure 22 are an integral structure.

[0102] In addition, there are various structural designs for the flow channel 3. For example, the flow channel 3 is formed between the inner wall of the working hole 13, the outer surface of the fixing part 212 and the snap-fit ​​part 211; or, a part of the flow channel 3 is formed between the inner wall of the working hole 13, the outer surface of the fixing part 212 and the snap-fit ​​part 211, and another part passes through the fixing part 212 and extends out of the fixing part 212 toward the outer surface of the second side 12, etc.

[0103] This design, with the valve body 21 consisting of a snap-fit ​​part 211 and a fixing part 212, allows the valve body 21 to be stably snapped into the working hole 13; at the same time, it also facilitates the formation of the flow passage 3 to achieve effective pressure relief.

[0104] Optionally, according to some embodiments of this application, please refer to Figure 5 At least one of the end cap 1 facing the second side 12 and the snap-fit ​​portion 211 is provided with a flow groove 14 communicating with the second side 12. A flow gap 24 is formed between the fixing portion 212 and the inner wall of the working hole 13. The flow groove 14 and the flow gap 24 communicate to define and form a flow channel 3.

[0105] The flow channel 14 refers to the space located between the end cap 1 and the latching part 211. It can be formed by inwardly recessing at least one surface of the end cap 1 and the latching part 211, and one end of the flow channel 14 extends to communicate with the working hole 13. For example, the flow channel 14 is provided on the surface of the end cap 1 and extends to the inner wall of the working hole 13; or, the flow channel 14 is provided on the latching part 211; or, the flow channel 14 is provided on both the surface of the end cap 1 and the latching part 211. When the sealing structure 22 is separated from the end cap 1, the airflow on the second side 12 can pass through the flow channel 14 and the flow gap 24 in sequence, thereby being discharged to the first side 11.

[0106] The flow gap 24 refers to the space formed between the inner wall of the working hole 13 and the fixing part 212, which, together with the flow groove 14, can define and form the flow channel 3. The flow gap 24 is located between the inner wall of the working hole 13 and the fixing part 212, and can be arranged in a ring around the outer periphery of the fixing part 212.

[0107] This design, which introduces the flow channel 14 and the flow gap 24, allows the airflow to be stably discharged to the first side 11 during depressurization.

[0108] Optionally, according to some embodiments of this application, please refer to Figure 7 and Figure 8 The flow channel 14 is provided on a surface of the end cap 1 facing the second side 12, and one end of it extends to communicate with the working hole 13.

[0109] It is easy to understand that, in order to achieve effective pressure relief, the flow channel 3 needs to be connected to the second side 12. Therefore, when the valve body 21 is assembled in the working hole 13, the snap-fit ​​part 211 abuts against the surface of the end cover 1 facing the second side 12, but does not completely cover the flow channel 14. For example, the end of the flow channel 14 away from the working hole 13 extends out of the snap-fit ​​part 211, so that part of the flow channel 14 is exposed in the second side 12, so that the airflow can stably enter the flow gap 24 from the flow channel 14; or, the end of the flow channel 14 away from the working hole 13 does not extend out of the snap-fit ​​part 211, but there is a gap between it and the snap-fit ​​part 211.

[0110] This design extends one end of the flow channel 14 beyond the snap-fit ​​part 211 and connects the other end to the working hole 13, allowing the airflow to stably pass through the flow channel 14 into the flow gap 24, thus achieving effective and stable pressure relief.

[0111] Optionally, according to some embodiments of this application, please refer to Figure 8 The flow channel 14 includes multiple channels, and at least some of the flow channels 14 are distributed at intervals around the outer periphery of the working hole 13.

[0112] At least some of the flow channels 14 are distributed at intervals around the outer periphery of the working hole 13, so that the airflow on the second side 12 can enter the flow gap 24 from different directions. The specific number of flow channels 14 can be determined according to actual needs.

[0113] This design, with the flow channels 14 spaced around the outer periphery of the working hole 13, allows the airflow from the second side 12 to enter the flow gap 24 from different directions, which can reduce the pressure relief and improve the pressure relief efficiency.

[0114] Optionally, according to some embodiments of this application, please refer to Figure 5 and Figure 6The side of the snap-fit ​​portion 211 facing the sealing structure 22 includes an abutment surface 21a around the outer periphery of the fixing portion 212. The area A2 of the cross section of the abutment surface 21a perpendicular to the axis 23 of the pressure relief valve 2 gradually increases from the end of the abutment surface 21a near the fixing portion 212 to the end of the abutment surface 21a away from the fixing portion 212.

[0115] The contact surface 21a is inclined relative to the axis 23 of the pressure relief valve 2. The cross-sectional area of ​​the contact surface 21a is smaller closer to the fixing part 212, and the whole is a part of an inverted conical surface. When the valve body 21 is assembled in the end of the working hole 13 facing the second side 12, it can achieve effective self-centering under the action of the contact surface 21a, so that the valve body 21 is stably assembled in the preset position, which can reduce the assembly accuracy requirements.

[0116] Meanwhile, the contact surface 21a is part of an inverted conical surface. When the contact surface 21a abuts against a surface of the end cap 1 facing the second side 12, the end of the contact surface 21a away from the fixing part 212 can easily form a gap with the end cap 1, so that the airflow in the second side 12 can easily enter the flow channel 3.

[0117] This design makes the cross-sectional area of ​​the contact surface 21a smaller as it gets closer to the fixing part 212, so that the assembly of the valve body 21 can achieve self-centering under the guidance of the contact surface 21a, reducing the requirements for assembly accuracy. At the same time, the design of the contact surface 21a, while ensuring stable contact with the end cover 1, makes it easy to form a gap with the surface of the end cover 1, which facilitates the airflow into the flow channel 3 and facilitates stable pressure relief.

[0118] Optionally, according to some embodiments of this application, please refer to Figure 5 and Figure 6 The side of the snap-fit ​​part 211 facing away from the sealing structure 22 includes a guide surface 21b. The area A3 of the cross-section of the guide surface 21b perpendicular to the axis 23 of the pressure relief valve 2 gradually decreases from the end of the guide surface 21b near the fixing part 212 to the end of the guide surface 21b away from the fixing part 212.

[0119] It can be seen that the cross-sectional area of ​​the guide surface 21b is larger as it gets closer to the fixing part 212. When the valve body 21 is inserted into the working hole 13 in a manner from the first side 11 to the second side 12, the guide surface 21b can play an effective guiding role, so that the valve body 21 can be quickly assembled in the working hole 13.

[0120] At the same time, it is easy to understand that the area A3 of the cross section of the guide surface 21b gradually decreases from the end of the guide surface 21b near the fixed part 212 to the end of the guide surface 21b away from the fixed part 212, indicating that the guide surface 21b presents an annular cylindrical curved surface, and the area A3 of the cross section can also be understood as the area of ​​the cross section perpendicular to the axis 23 of the pressure relief valve 2 that the guide surface 21b can enclose to form the internal space.

[0121] This design, with its rationally designed structure of the guide surface 21b, allows the valve body 21 to be quickly and stably assembled into the working hole 13 under the guidance of the guide surface 21b, thereby improving assembly efficiency.

[0122] According to some embodiments of this application, please refer to Figure 6 This application provides a pressure relief valve 2, which includes a valve body 21 and a sealing structure 22. The sealing structure 22 is disposed on the valve body 21, and the portion of the sealing structure 22 extending radially beyond the valve body 21 is configured to be able to warp and deform in a direction away from the valve body 21.

[0123] In this embodiment, the pressure relief valve 2 can be installed in the working hole 13 of the end cap 1. The end cap 1 has a first side 11 and a second layer along its thickness direction X. When the pressure relief valve 2 is installed in the working hole 13, a flow channel 3 communicating with the second side 12 is formed between the valve body 21 and the end cap 1. The sealing structure 22 can seal the portion of the working hole 13 facing the first side 11. When the internal air pressure of the battery cell 110 increases, the air pressure pushes open the sealing structure 22 from the second side 12 to the first side 11, causing it to warp and separate from the end cap 1, forming a gap that allows the airflow in the flow channel 3 to be discharged to the first side 11. The sealing structure 22 can be an elastic component, such as rubber material, which separates from the end cap 1 and forms a gap under the action of air pressure by warping. When the air pressure decreases, the sealing structure 22 automatically recovers its deformation and re-seales with the end cap 1. In some examples, when the internal air pressure of the battery cell 110 reaches above 0.01 MPa, the sealing structure 22 can be opened to release pressure and vent air.

[0124] In this embodiment, valve body 21 refers to a structure used for assembly in working hole 13, which forms a flow channel 3 with working hole 13. The sealing structure 22 refers to a structure that seals the portion of working hole 13 facing the first side 11, isolating the flow channel 3 from the first side 11 and reducing the entry of gas or liquid from the first side 11 into the flow channel 3, thus achieving effective water isolation. Furthermore, in this embodiment, valve body 21 and sealing structure 22 can be the same as those in any of the above embodiments.

[0125] With this design, the pressure relief valve 2 can effectively isolate water and relieve pressure, while being reusable, thus reducing production costs.

[0126] Optionally, according to some embodiments of this application, please refer to Figure 6 The sealing structure 22 is provided on the valve body 21 with a first sealing member 221 and a second sealing member 222 on the side of the first sealing member 221 facing away from the valve body 21. Both the first sealing member 221 and the second sealing member 222 are configured to be able to warp and deform in the direction away from the valve body 21.

[0127] The second sealing element 222 is disposed on the side of the first sealing element 221 facing away from the valve body 21. This means that the first sealing element 221 and the second sealing element 222 are sequentially distributed along the thickness direction X of the end cover 1, achieving a double seal in the thickness direction X of the end cover 1. When the internal pressure of the battery cell 110 exceeds a certain value, such as a pressure value greater than or equal to 0.01 MPa, the air pressure can first cause the first sealing element 221 to warp and deform, separating it from the end cover 1, such as separating it from at least part of the inner wall of the working hole 13, allowing airflow to be discharged between the first sealing element 221 and the second sealing element 222. Then, the air pressure further drives the second sealing element 222 to warp and deform, causing the second sealing element 222 to also separate from the end cover 1, allowing airflow to be discharged outside the second sealing element 222.

[0128] When the internal air pressure of the battery cell 110 decreases, the first sealing member 221 can re-abut against the circumferential inner wall of the working hole 13 before the second sealing member 222. The materials of the first sealing member 221 and the second sealing member 222 can be the same or different. For example, the elastic modulus of the material of the second sealing member 222 can be less than that of the material of the first sealing member 221. This satisfies the air pressure required to open the first sealing member 221 and can also effectively open the second sealing member 222, thus achieving effective pressure relief.

[0129] The circumferential inner wall of the working hole 13 refers to the annular inner wall along its own circumference on the working hole 13. When the first sealing member 221 and the second sealing member 222 respectively abut against the circumferential inner wall of the working hole 13, the end of the working hole 13 facing the first side 11 can be sealed, reducing the possibility of external gas or liquid entering the battery cell 110 and achieving effective water isolation.

[0130] To facilitate the warping deformation of the first sealing element 221 and the second sealing element 222, both the first sealing element 221 and the second sealing element 222 can be made of elastic materials, such as rubber. At the same time, the shapes of the first sealing element 221 and the second sealing element 222 can be designed in various ways, such as, but not limited to, circles, ovals, squares, pentagons, etc.

[0131] Furthermore, the first sealing element 221 is connected to the valve body 21 in various ways, such as threaded connection, snap-fit, adhesive bonding, or integral molding. Similarly, the connection between the second sealing element 222 and the first sealing element 221 can also be, but is not limited to, threaded connection, snap-fit, adhesive bonding, or integral molding. In some specific embodiments, the first sealing element 221, the second sealing element 222, and the valve body 21 are an integrated structure.

[0132] This design introduces a first sealing element 221 and a second sealing element 222 to achieve a double-layer seal on one end of the working hole 13, further improving the reliability of water-proofing.

[0133] Optionally, according to some embodiments of this application, please refer to Figure 6 The valve body 21 includes a snap-fit ​​part 211 and a fixing part 212 connected to the snap-fit ​​part 211. The sealing structure 22 is connected to the fixing part 212 and spaced apart from the snap-fit ​​part 211.

[0134] The snap-fit ​​part 211 abuts against a surface of the end cap 1 facing the second side 12, and the sealing structure 22 seals a portion of the working hole 13 facing the first side 11; at the same time, a fixing part 212 is connected between the snap-fit ​​part 211 and the sealing structure 22. In this way, the snap-fit ​​part 211 and the sealing structure 22 can be combined to form a clamping structure, so that the pressure relief valve 2 is stably clamped in the working hole 13.

[0135] The connection method between the fixing part 212 and the locking part 211 and the sealing structure 22 can be adhesive bonding, snap-fitting, threaded connection, integral molding, etc. Specifically, in some embodiments, the locking part 211, the fixing part 212 and the sealing structure 22 are an integral structure.

[0136] In addition, there are various structural designs for the flow channel 3. For example, the flow channel 3 is formed between the inner wall of the working hole 13, the outer surface of the fixing part 212 and the snap-fit ​​part 211; or, a part of the flow channel 3 is formed between the inner wall of the working hole 13, the outer surface of the fixing part 212 and the snap-fit ​​part 211, and another part passes through the fixing part 212 and extends out of the fixing part 212 toward the outer surface of the second side 12, etc.

[0137] This design, with the valve body 21 consisting of a snap-fit ​​part 211 and a fixing part 212, allows the valve body 21 to be stably snapped into the working hole 13; at the same time, it also facilitates the formation of the flow passage 3 to achieve effective pressure relief.

[0138] According to some embodiments of this application, this application provides a battery cell 110, which includes the end cap assembly 10 of any of the above.

[0139] According to some embodiments of this application, this application provides a battery 100, which includes the above-mentioned battery cells 110.

[0140] According to some embodiments of this application, this application provides an electrical device, which includes the battery 100 described above.

[0141] According to some embodiments of this application, please refer to Figures 4 to 8 This application provides a pressure relief valve 2, which includes a valve body 21, a first sealing element 221, and a second sealing element 222. The first sealing element 221 is disposed on the valve body 21, and the second sealing element 222 is disposed on the side of the first sealing element 221 facing away from the valve body 21. A pressure cavity 223 is provided between the first sealing element 221 and the second sealing element 222. When the pressure relief valve 2 is assembled in the working hole 13 of the end cover 1, both the first sealing element 221 and the second sealing element 222 are sealed against the circumferential inner wall of the working hole 13. At the same time, the edges of the first sealing element 221 and the second sealing element 222 can be warped and deformed to separate from the end cover 1, thereby realizing the pressure relief of the battery cell 110.

[0142] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0143] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An end cap assembly, characterized by, The end cover assembly comprises: an end cover (1) having a first side (11) and a second side (12) in a thickness direction (X) of the end cover (1), and a working hole (13) extending through the first side (11) and the second side (12); a pressure relief valve (2) comprising a valve body (21) and a blocking structure (22), the valve body (21) being at least partially arranged in the working hole (13) and forming a flow passage (3) with the end cover (1) to communicate with the second side (12), the blocking structure (22) being blocked on a portion of the working hole (13) towards the first side (11) and being configured to be at least partially separated from the end cover (1) when subjected to a pressure directed from the second side (12) to the first side (11) so as to make the flow passage (3) communicate with the first side (11).

2. The end cap assembly of claim 1, wherein, The blocking structure (22) comprises a first blocking piece (221) arranged on the valve body (21) and a second blocking piece (222) arranged on a side of the first blocking piece (221) away from the valve body (21), the first blocking piece (221) and the second blocking piece (222) are both sealingly abutted on a circumferential inner wall of the working hole (13), and both are configured to be separated from the end cover (1) when subjected to a pressure directed from the second side (12) to the first side (11).

3. The end cap assembly of claim 2, wherein, A pressure cavity (223) is formed between the first blocking piece (221) and the second blocking piece (222), and the pressure cavity (223) is configured to communicate with the flow passage (3) when the first blocking piece (221) is separated from the end cover (1).

4. The end cap assembly of claim 3, wherein, The second blocking piece (222) comprises a connecting portion (22c) and a blocking portion (22d), the blocking portion (22d) is connected to the first blocking piece (221) through the connecting portion (22c) and is sealingly abutted on the circumferential inner wall of the working hole (13), at least part of the pressure cavity (223) is enclosed between the blocking portion (22d), the connecting portion (22c) and the first blocking piece (221).

5. The end cap assembly of claim 4, wherein, A circumferential edge (22b) of the blocking portion (22d) is outside the connecting portion (22c) in a radial direction of the pressure relief valve (2) and is arranged to be bent towards a side of the valve body (21).

6. The end cap assembly of claim 2, wherein, A projection of the second blocking piece (222) in a direction of an axis (23) of the pressure relief valve (2) covers the first blocking piece (221) and is outside the first blocking piece (221) in a radial direction of the pressure relief valve (2).

7. An end cap assembly according to any one of claims 2 to 6, wherein, The working hole (13) comprises a first hole section (131), a second hole section (132) and a third hole section (133) arranged in sequence in the thickness direction (X) of the end cover (1), the third hole section (133) is arranged close to the second side (12), the valve body (21) is at least partially arranged in the third hole section (133), the first blocking piece (221) is sealingly abutted on an inner wall of the second hole section (132), and the second blocking piece (222) is sealingly abutted on an inner wall of the first hole section (131).

8. The end cap assembly of claim 7, wherein, An area A1 of a cross section of the second hole section (132) gradually increases from one end of the second hole section (132) close to the third hole section (133) to the other end of the second hole section (132) close to the first hole section (131), and a side surface of the first blocking member (221) away from the second blocking member (222) abuts against an inner wall of the second hole section (132).

9. The end cap assembly of claim 8, wherein, The side surface of the first blocking member (221) away from the second blocking member (222) comprises a sealing surface (22a) annularly surrounding an axis (23) of the pressure relief valve (2), and the sealing surface (22a) and the inner wall of the second hole section (132) are both inclined relative to the axis (23) of the pressure relief valve (2). An angle θ1 between the sealing surface (22a) and the axis (23) is greater than or equal to an angle θ2 between the inner wall of the second hole section (132) and the axis (23).

10. The end cap assembly of any one of claims 1-6, wherein, The valve body (21) comprises a clamping portion (211) and a fixed portion (212) connected to the clamping portion (211), the fixed portion (212) is arranged in the work hole (13), the clamping portion (211) abuts against a surface of the end cover (1) facing the second side (12), the blocking structure (22) is connected to the fixed portion (212), and the clamping portion (211), the fixed portion (212) and the end cover (1) define the flow passage (3).

11. The end cap assembly of claim 10, wherein, At least one of the surface of the end cover (1) facing the second side (12) and the clamping portion (211) is provided with a flow groove (14) in communication with the second side (12), a flow gap (24) is formed between the fixed portion (212) and the inner wall of the work hole (13), and the flow groove (14) is in communication with the flow gap (24) to define the flow passage (3).

12. The end cap assembly of claim 11, wherein, The flow groove (14) is arranged on the surface of the end cover (1) facing the second side (12), and one end of the flow groove (14) extends to be in communication with the work hole (13).

13. The end cap assembly of claim 12, wherein, The flow groove (14) comprises a plurality of flow grooves (14), and at least part of the flow grooves (14) are distributed at intervals around the outer periphery of the work hole (13).

14. The end cap assembly of claim 10, wherein, A side surface of the clamping portion (211) facing the blocking structure (22) comprises an abutting surface (21a) around the outer periphery of the fixed portion (212), and an area A2 of a cross section of the abutting surface (21a) perpendicular to the axis (23) of the pressure relief valve (2) gradually increases from one end of the abutting surface (21a) close to the fixed portion (212) to the other end of the abutting surface (21a) away from the fixed portion (212).

15. The end cap assembly of claim 10, wherein, A side surface of the clamping portion (211) away from the blocking structure (22) comprises a guide surface (21b), and an area A3 of a cross section of the guide surface (21b) perpendicular to the axis (23) of the pressure relief valve (2) gradually decreases from one end of the guide surface (21b) close to the fixed portion (212) to the other end of the guide surface (21b) away from the fixed portion (212).

16. A pressure relief valve (2) characterized by The pressure relief valve (2) comprises: a valve body (21); A blocking structure (22) is arranged on the valve body (21), and a portion of the blocking structure (22) beyond the valve body (21) in the radial direction of the pressure relief valve (2) is configured to be able to be deformed in a buckling manner in a direction away from the valve body (21).

17. The pressure relief valve (2) according to claim 16, characterized in that The blocking structure (22) is arranged on a first blocking member (221) of the valve body (21) and a second blocking member (222) arranged on a side of the first blocking member (221) away from the valve body (21), and the first blocking member (221) and the second blocking member (222) are both configured to be able to be deformed in a buckling manner in a direction away from the valve body (21).

18. Pressure relief valve (2) according to claim 16 or 17, characterized in that The valve body (21) comprises a clamping portion (211) and a fixed portion (212) connected to the clamping portion (211), and the blocking structure (22) is connected to the fixed portion (212) and is spaced apart from the clamping portion (211).

19. A battery cell, characterized by The battery monomer comprises the end cover assembly of any one of claims 1-15.

20. A battery, characterized by The battery comprises the battery monomer of claim 19.

21. An electrical device, comprising: The electric device comprises the battery of claim 20.

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